• TABLE OF CONTENTS
HIDE
 Front Cover
 Front Matter
 Table of Contents
 Introduction
 Factors affecting hay grown for...
 Estimated cost of installation...
 Farmer acceptance
 Selecting equipment
 Sources of power to operate...
 Drive
 Design of air heater
 Chimney
 Field preparation and curing...
 Seed drying
 Summary






Group Title: Bulletin - University of Florida Agricultural Experiment Station ; 477
Title: Hay and seed drying with a slatted floor system
CITATION PAGE IMAGE ZOOMABLE PAGE TEXT
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00026560/00001
 Material Information
Title: Hay and seed drying with a slatted floor system
Series Title: Bulletin University of Florida. Agricultural Experiment Station
Physical Description: 46 p. : ill., charts, plans ; 23 cm.
Language: English
Creator: Myers, J. Mostella ( Julian Mostella ), 1921-
Killinger, G. B ( Gordon Beverly ), 1908-
Bledsoe, R. W
Publisher: University of Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1951
 Subjects
Subject: Hay -- Drying -- Florida   ( lcsh )
Haying equipment   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Bibliography: p. 46.
Statement of Responsibility: by J.M. Myers, G.B. Killinger and R.W. Bledsoe.
General Note: Cover title.
Funding: This collection includes items related to Florida’s environments, ecosystems, and species. It includes the subcollections of Florida Cooperative Fish and Wildlife Research Unit project documents, the Florida Sea Grant technical series, the Florida Geological Survey series, the Howard T. Odum Center for Wetland technical reports, and other entities devoted to the study and preservation of Florida's natural resources.
 Record Information
Bibliographic ID: UF00026560
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000925732
oclc - 18265189
notis - AEN6388

Table of Contents
    Front Cover
        Page 1
    Front Matter
        Page 2
        Page 3
    Table of Contents
        Page 4
    Introduction
        Page 5
    Factors affecting hay grown for artificial drying
        Page 6
        Page 7
    Estimated cost of installation of an artificial drier
        Page 8
        Cost of operation
            Page 8
    Farmer acceptance
        Page 9
        Design of hay drier
            Page 9
            Page 10
        Ventilation of mow
            Page 11
        Mow floor
            Page 11
        Hay track and fork
            Page 12
        Parts and functional uses
            Page 12
            Page 13
        Types of air distribution systems
            Page 14
            Page 15
        Design of main duct
            Page 16
        Design of slatted floor distribution system
            Page 17
            Page 18
    Selecting equipment
        Page 19
        Volume of air needed
            Page 19
        Types of fans suitable for hay drying
            Page 20
        Characteristics of fans
            Page 20
    Sources of power to operate fan
        Page 21
    Drive
        Page 22
        Supplemental heat
            Page 22
        Amount of heat required
            Page 23
        Sources of supplemental heat
            Page 24
            Page 25
            Page 26
    Design of air heater
        Page 27
    Chimney
        Page 28
        Portable driers
            Page 28
    Field preparation and curing methods
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
    Seed drying
        Page 36
        Page 37
        Page 38
        Page 39
        Page 40
        Page 41
        Page 42
        Page 43
        Page 44
        Page 45
    Summary
        Page 46
        Literature Cited
            Page 46
Full Text


Bulletin 477 ,


UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATIONS
WILLARD M. FIFIELD, Director
GAINESVILLE, FLORIDA




Hay and Seed Drying With A

Slatted Floor System


by

J. M. MYERS, G. B. KILLINGER and R. W. BLEDSOE


Fig. 1.-Pangola grass hay being windrowed
Florida Agricultural Experiment Station farm.


at the University of


May 1951











BOARD OF CONTROL

Frank M. Harris, Chairman, St. Peters-
burg
N. B. Jordan, Quincy
Hollis Rinehart, Miami
Eli H. Fink, Jacksonville
George J. White, Sr., Mount Dora
W. F. Powers, Secretary, Tallahassee
EXECUTIVE STAFF
J. Hillis Miller, Ph.D., Presidents
J. Wayne Reitz, Ph.D., Provost for Agr.'
Willard M. Fifield, M.S., Director
J. R. Beckenbach, Ph.D., Asso. Director
L. 0. Gratz, Ph.D., Asst. Dir., Research
Geo. F. Baughman, M.S., Business Mgr.'
Rogers L. Bartley, B.S., Admin. Mgr.8
Claranelle Alderman, Accountants

MAIN STATION, GAINESVILLE
AGRICULTURAL ECONOMICS
H. G. Hamilton, Ph.D., Agr. Econo-
mist1 8
R. E. L. Greene, Ph.D., Agr. Economist
Zach Savage, M.S.A., Associate
A. H. Spuriock, M.S.A., Associate
D. E. Alleger, M.S., Associate
D. L. Brooke, M.S.A., Associate
M. R. Godwin, Ph.D., Associate
H. W. Little, M.S., Assistant4
Tallmadge Bergen, B.S., Assistant
D. C. Kimmel, Ph.D., Assistant
A. L. Larson, Ph.D., Agr. Economist
Orlando, Florida (Cooperative USDA)
G. Norman Rose, B.S., Asso. Agr.
Economist
J. C. Townsend, Jr., B.S.A., Agr.
Statistician'
J. B. Owens, B.S.A., Agr. Statistician
AGRICULTURAL ENGINEERING
Frazier Rogers, M.S.A., Agr. Engineer' *
J. M. Johnson, B.S.A.E., Asso. Agr. Eng."
J. M. Myers, B.S., Asso. Agr. Engineer
R. E. Choate, B.S.A.E., Asst. Agr. Engr.'
A. M. Pettis, B.S.A.E., Asst. Agr. Eng.2 *
AGRONOMY
Fred. H. Hull, Ph.D., Agronomist'
G. B. Killinger, Ph.D., Agronomists
H. C. Harris, Ph.D.. Agronomist
R. W. Bledsoe, Ph.D., Agronomist
W. A. Carver, Ph.D., Associate
Darrel D. Morey, Ph.D., Associate
Fred A. Clark, B.S., Assistant
Myron C. Grennell, B.S.A.E., Assistant
E. S. Horner, Ph.D.. Assistant
A. T. Wallace, Ph.D., Assistant
D. E. McCloud, Ph.D.. Assistant
ANIMAL HUSH. AND NUTRITION
T. J. Cunha, Ph.D., An. Hush.H s
R. S. Glasscock, Ph.D., An. Hush."
G. K. Davis, Ph.D., Animal Nutritionist'
R. L. Shirley, Ph.D., Biochemist'
J. E. Pace, M.S., Asst. An. Husb.'
S. John Folks, B.S.A., Asst. An. Husb.*
Katherine Boney, B.S., Asst. Chem.
James M. Wing, M.S., Asst. Dairy Husb.
A. M Pearson, Ph.D., Asst. An. Husb.'
John D. Feaster, Ph.D., An. Nutritionist
H. D. Wallace, Ph.D., Asst. An. Hush.
DAIRY SCIENCE
E. L. Fouts, Ph.D., Dairy Tech.' '
R. B. Becker, Ph.D., Dairy Hush."
S. P. Marshall, Ph.D., Asso. Dairy
Hush.'
W. A. Krlenke, M.S., Asso. in Dairy Mfs."
P. T. Dix Arnold, M.S.A., Asst. Dairy
Husb.'
Leon Mull, Ph.D., Asst. Dairy Tech.
H. Wilkowske, Ph.D., Asst. Dairy Tech.


EDITORIAL
J. Francis Cooper, M.S.A., Editor'
Clyde Beale, A.B.J., Associate Editor'
L. Odell Griffith, B.A.J., Asst. Editor'
J. N. Joiner, B.S.A., Assistant Editor' 4
ENTOMOLOGY
A. N. Tissot, Ph.D., Entomologist'
L. C. Kuitert, Ph.D., Associate
H. E. Bratley, M.S.A., Assistant
F. A. Robinson, M.S., Asst. Apiculturist

HOME ECONOMICS
Ouida D. Abbott, Ph.D., Home Econ.'
R. B. French, Ph.D., Biochemist

IIORTICULTURE
G. H. Blackmon, M.S.A., Horticulturist'
F. S. Jamison, Ph.D., Horticulturist'
Albert P. Lorz, Ph.D., Horticulturist
H. M. Reed, B.S., Chem., Veg. Processing
R. K. Showalter, M.S., Asso. Hort.
R. A. Dennison, Ph.D., Asso. Hort.
R. H. Sharpe, M.S.. Asso. Horticulturist
F. S. Lagasse, Ph.D., Asso. Hort.2
R. D. Dickey, M.S.A., Asst. Hort.
L. H. Halsey, M.S.A., Asst. Hort.
C. D. Hall, Ph.D., Asst. Horticulturist
S. E. McFadden, Ph.D., Asst. Hort.
Austin Griffiths, Jr., B.S., Asst. Hort.
LIBRARY
Ida Keeling Cresap, Librarian
PLANT PATHOLOGY
W. B. Tisdale, Ph.D., Plant Patholo-
gist' '
Phares Decker, Ph.D., Plant Pathologist
Erdman West, M.S., Mycologist and
Botanist
Robert W. Earhart, Ph.D., Plant Path.'
Howard N. Miller, Ph.D., Asso. Plant
Path.
Lillian E. Arnold, M.S., Asst. Botanist
C. TV. Anderson, Ph.D., Asst. Plant Path.
POULTRY HUSBANDRY
N. R. Mehrhof, M.Agr., Poultry Husb.1 '
J. C. Driggers, Ph.D., Asso. Poultry
Husb.
SOILS
F. B. Smith, Ph.D., Microbiologist' s
Gaylord M. Volk, Ph.D., Chemist
J. R. Henderson, M.S.A., Soil Technolo-
gist'
J. R. Neller, Ph.D., Soils Chemist
Nathan Gammon, Jr., Ph.D., Soils
Chemist
R. A. Carrigan, Ph.D., Biochemist'
Ralph G. Leighty, B.S., Asso. Soil
Surveyor'
G. D. Thornton, Ph.D., Asso.4
Microbiologist'
Charles F. Eno, Ph.D., Asst. Soils
Microbiologist
H. W. Winsor, B.S.A., Assistant Chemist
R. E. Caldwell, M.S.A., Asst. Chemists
V. W. Carlisle, B.S., Asst. Soil Surveyor
James H. Walker, M.S.A., Asst. Soil
Surveyor
S. N. Edson, M. S., Asst. Microbiologist
William K. Robertson, Ph.D., Asst.
Chemist
O. E. Cruz, B.S.A., Asst. Soil Surveyor
%T. G. Blue, Ph.D., Asst. Biochemist
VETERINARY SCIENCE
D. A. Sanders, D.V.M., Veterinarian'
M. W. Emmel, D.V.M., Veterinarian'
C. F. Simpson, D.V.M., Asso.
Veterinarian
L. E. Swanson, D.V.M., Parasitologist
Glenn Van Ness, D.V.M., Asso. Poultry
Pathologist
G. E. Batte, D.V.M., Asso. Parasitologist










BRANCH STATIONS

NORTH FLORIDA STATION, QUINCY
J. D. Warner, M.S., Vice-Director in
Charge
R. R. Kincaid, Ph.D., Plant Pathologist
L. G. Thompson, Ph.D., Soils Chemist
W. C. Rhoads, M.S., Entomologist
W. H. Chapman, M.S., Asso. Agronomist
Frank S. Baker, Jr., B.S., Asst. An.
Husb.
Mobile Unit, Monticello
R. W. Wallace, B.S., Associate
Agronomist
Mobile Unit, Marlanna
R. W. Lipscomb, M.S., Associate
Agronomist
Mobile Unit, Pensacola
R. L. Smith, M.S., Associate Agronomist

Mobile Unit, Chipley
J. B. White, B.S.A., Associate
Agronomist
CITRUS STATION, LAKE ALFRED
A. F. Camp, Ph.D., Vice-Director in
Charge
W. L. Thompson, B.S., Entomologist
J. T. Griffiths, Ph.D., Asso.
Entomologist
R. F. Suit, Ph.D., Plant Pathologist
E. P. Ducharme, Ph.D., Asso. Plant
Path.4
R. K. Voorhees, Ph.D., Asso.
Horticulturist
C. R. Stearns, Jr., B.S.A., Asso. Chemist
J. W. Sites, M.S.A., Horticulturist
H. 0. Sterling, B.S., Asst. Horticulturist
H. J. Reitz, Ph.D., Asso. Horticulturist
Francine Fisher, M.S., Asst. Plant Path.
I. W. Wander, Ph.D., Soils Chemist
J. W. Kesterson, M.S., Asso. Chemist
R N. Hendrickson, B.S., Asst. Chemist
J. C. Bowers, M.S., Asst. Chemist
D. S. Prosser, Jr., B.S., Asst.
Horticulturist
R. W. Olsen, B.S., Biochemist
F. W. Wenzel, Jr., Ph.D., Supervisory
Chem.
Alvin H. Rouse, M.S., Asso. Chemist
H. W. Ford, Ph.D., Asst. Horticulturist
L. W. Faville, Ph.D., Asst. Chemist
L. C. Knorr, Ph.D., Asso. Histologist'
R. M. Pratt, B.S., Asso. Ent.-Pathologist
W. A. Simanton, Ph.D., Entomologist
E. J. Desyck, Ph.D., Asso. Horticulturist
C. D. Leonard, Ph.D., Asso. Horticul-
turist
EVERGLADES STATION,
BELLE GLADE
R. V. Allison, Ph.D., Vice-Director in
Charge
Thomas Bregger, Ph.D., Sugar
Physiologist
J. W. Randolph, M.S., Agricultural Egr.
W. T. Forsee, Jr., Ph.D., Chemist
R. W. Kidder, M.S., Asso. Animal Husb.
T. C. Erwin, Assistant Chemist
C. C. Seale, Asso. Agronomist
N. C. Hayslip, B.S.A., Asso, Entomolo-
gist
E. A. Wolf, M.S., Asst. Horticulturist
W. H. Thames, M.S., Asst. Entomologist
W. N. Stoner, Ph.D., Asst. Plant Path.
W. A. Hills, M.S., Asso. Horticulturist
W. G. Genung, B.S.A., Asst. Entomologist
D. W. Smith, B.S., Asst. Chemist
Frank V. Stevenson, M.S., Asso. Plant
Pathologist
Raymond H. Webster, Ph.D., Asst.
Agronomist
Robert J. Allen, M.S., Asst. Agronomist


SUB-TROPICAL STATION,
HOMESTEAD
Geo. D. Ruehle, Ph.D., Vice-Dir. in
Charge
D. 0. Wolfenbarger, Ph.D., Entomologist
Francis B. Lincoln, Ph.D., Horticulturist
Milton Cobin, B.S., Asso. Horticulturist
Robert A. Conover, Ph.D., Plant Path.
John L. Malcolm, Ph.D., Asso. Soils
Chemist
R. W. Harkness, Ph.D., Asst. Chemist

W. CENT. FLA. STATION,
BROOKSVILLE
William Jackson. B.S.A., Animal
Husbandman in Charge2
RANGE CATTLE STATION, ONA
W. G. Kirk, Ph.D., Vice-Director in
Charge
E. M. Hodges, Ph.D., Agronomist
D. W. Jones, M.S., Asst. Soil
Technologist
CENTRAL FLORIDA STATION,
SANFORD
R. W. Ruprecht, Ph.D., Vice-Dir. in
Charge
J. W. Wilson, Sc.D., Entomologist
P. J. Westgate, Ph.D., Asso. Hort.
Ben. F. Whitner, Jr., B.S.A., Asst. Hort.
Geo. Swank, Jr., Ph.D., Asst. Plant Path.
W. FLA. STATION, JAY
C. E. Hutton, Ph.D., Vice-Director in
Charge
H. W. Lundy, B.S.A., Associate
Agronomist

SUWANEE VALLEY STA., LIVE OAK
G. E.. Ritchey, M.S., Agronomist in
Charge
GULF COAST STA., BRADENTON
E. L. Spencer, Ph.D., Soils Chemist in
Charge
E. G. Kelsheimer, Ph.D., Entomologist
David G. Kelbert, Asso. Horticulturist
Robert O. Magie, Ph.D., Gladioli Hort.
J. M. Walter, Ph.D., Plant Pathologist
Donald S. Burgis, M.S.A., Asst. Hort.
C. M. Geraldson, Ph.D., Asst. Hort.


FIELD LABORATORIES

Watermelon, Grape, Pasture-Leesburg
G. K. Parris, Ph.D., Plant Path. in
Charge
C. C. Helms, Jr., B.S., Asst. Agronomist

Strawberry-Plant City
A. N. Brooks, Ph.D., Plant Pathologist

Vegetables-Hastings
A. H. Eddins, Ph.D., Plant Path. Jin
Charge
E. N. McCubbin, Ph.D., Horticulturist

SPecans-Monticello
A. M. Phillips, B.S., Asso. Entomologist2
John R. Large, M.S., Asso. Plant Path.

Frost Forecasting-Lakeland
Warren O. Johnson, B.S., Meterologist'
SHead of Department
2 In cooperation with U. S.
a Cooperative, other divisions, U. of F.
*On leave.













CONTENTS


INTRODUCTION -----------.~...--.....----...--.. -.... 5
FACTORS AFFECTING HAY GROWN FOR ARTIFICIAL DRYING .....--.........--------. 6
ESTIMATED COST OF INSTALLATION OF AN ARTIFICIAL DRIER ..-.........--..... 8
COST OF OPERATION.--------------- ----. -.......... ......... 8
FARMER ACCEPTANCE -...--...--.............- .......----------... 9
DESIGN OF HAY DRIER ....... ..........--------------- ---- 9
Building Requirements .................----------------- 9
Roof--------------------- .....-...- ..-...-....-. --.. ------. 9
Ventilation of Mow ...............------------- 11
Mow Floor -...-.. .- -...........---..- .- ----- 11
Hay Track and Fork----------- --------- --- 12
Parts and Their Functional Uses ..--..-..... .........---------------- 12
Types of Air Distribution Systems .------- .. ..14
Design of Main Duct -._ ..........--------------.-- 16
Design of Slatted Floor Distribution System --._ --- 17
SELECTING EQUIPMENT ----.....---- ..- .... 19
Fan ---...................------------- -----...... .. ......-- ----- 19
Volume of Air Needed ...--- .- ..--- ----------------------- 19
Types of Fans Suitable for Hay Drying ....................... .......---------- 20
Characteristics of Fans .--...... .........--------------..-.... 20
SOURCES OF POWER TO OPERATE FAN --- ------~..--------.. 21
DRIVE --...- -----.~.--......... .. ... ...---------- 2....... 22
SUPPLEMENTAL HEAT -....-...------..--...~.. .. ........... 22
Amount of Heat Required -----------...- ..------- ....... 23
Sources of Supplemental Heat ._.. -------..... -. .............-------- 24
Type of Burner .... .... ... ...------------.-..........---. 24
Selection of Burner Size .........- ........------ .....---.. .. ----........... 24
DESIGN OF AIR HEATER ............------------.--..--.....-...- .....--- ...... 27
CHIMNEY -..... .... ...-- ......-- ........................-------- 28
PORTABLE DRIERS -.........-....... ............----------------------... ........ --.----.- 28
FIELD PREPARATION AND CURING METHODS --...-...... ...............---------- 29
SEED DRYING -- ----------.~ .... .....- ... 36
SUMMARY ..... ---......-._...-.... .-----.-... ..............----------.. 46
LITERATURE CITED --- ---------........--....-..--..- --. 46









Hay and Seed Drying With A

Slatted Floor System


By J. M. MYERS, G. B. KILLINGER and R. W. BLEDSOE


Introduction

It has been recognized for many years that the major limit-
ing factor in the production of high quality hay in Florida is
the difficulty encountered in curing. With plentiful rainfall,
especially during the summer, and a long growing season,
Florida's climatic conditions are ideal for growing hay crops
but very poor for curing hay. To produce high quality hay in
Florida, some method of curing other than in the field must be
used.
The field curing method has four major disadvantages: (1)
The fire hazard due to spontaneous combustion when hay is
placed in the barn before it is sufficiently dry; (2) loss of leaves
by shattering; (3) danger of damage or total loss due to rainfall;
and (4) reduction in quality by sunburning and bleaching. With
the barn curing method described below, fire hazard due to spon-
taneous combustion is practically eliminated because a continu-
ous flow of air through the hay prevents heat accumulation. The
loss of leaves by shattering and the chances of damage by rainfall
are reduced greatly if hay is placed in the barn soon after it is
cut. Hay usually can be placed in the barn the same day it is cut
when a drier is used, while hay left in the field usually requires
three days or longer before it is dry enough to be stored safely
in a barn. The reduction in quality of hay due to sunburning
and bleaching is less if hay is exposed to the sun for only a short
time.
During a hay-making season there are very few periods
when hay crops may be cut, dried in the field and stored in the
barn without some rain falling on the hay.
An analysis of weather data recorded in Jacksonville during
the hay-making season of 1947 indicates that there were only
20 drying periods during which hay could have been cut, dried
in the field and placed in the barn without some precipitation
on the hay. During that period there were 80 days suitable for
making hay to be dried on a barn hay drier. Even though the







Florida Agricultural Experiment Stations


records show that there were 20 periods suitable for field drying,
the chances of predicting the weather for two or more consecu-
tive days are many times less than predicting the weather for
one day. Actually, the risk of having hay damaged by rainfall
increases greatly when field drying is practiced.
The barn method of curing hay in Florida is somewhat more
difficult than that encountered in less humid regions of the
United States. Generally, unheated air is used to dry hay in
sections of the country where barn hay drying has been widely
accepted. Due to the high relative humidity of air in Florida,
sufficient drying cannot be done with air unless it is either heated
or dehumidified. At present it is less expensive to heat than to
dehumidify air. This means that if hay is mechanically dried in
Florida, the installation and operating cost of the equipment
will be slightly higher than in less humid regions.
Many farmers in Florida have a surplus of grasses and
legumes during the summer but are forced to buy hay during
the winter months to maintain the weight and health of their
livestock. Thousands of tons of high quality forage such as
clover, carpet grass, Pangola grass, Bahia grass, Bermuda grass,
Paragrass and Hairy indigo are lost because of lack of equip-
ment, labor and general information on how to preserve econom-
ically such feedstuffs. Florida farmers purchase many tons of
imported hay annually. High freight rates, together with other
factors, force both beef and dairy cattlemen to pay premium
prices for this imported hay.


Factors Affecting Hay Grown For Artificial Drying
Types of Hay Cured.-Several varieties of hay have been
cured in the experimental drier at the Experiment Station farm
near Gainesville. The most successful from an economic stand-
point were Hairy indigo, Pensacola Bahia, Pangola grass, Les-
pedeza and mixed hays. Cattail millet was dried on this experi-
mental drier but tests to date indicate a very high drying cost
for it. Generally speaking, hay crops that are not too stemmy
and do not have any peculiar water-holding characteristics are
best adapted to curing on a barn hay drier.
Yield, Composition and Curing Characteristics of Several
Grasses and Legumes Cut for Hay.-During the 1949 season a
two-acre tract of Pangola grass established in 1948 was fertil-
ized with 500 pounds per acre of 6-6-6 fertilizer on February 25








Hay and Seed Drying


and cut for hay on July 25. This particular tract of hay should
have been cut between June 10 and June 15, as it was just
coming into full bloom at that time. Conditions beyond control
made cutting at the proper time impossible. By July 25 it was
past the blooming stage and the deep blue-green color was fading
to a yellowish green. This cutting averaged 3.82 tons per acre
of barn-dried hay. The protein, mineral and feed analyses were
low as compared with Pangola cut for hay at a less mature stage.
The average composition of this barn of hay was as follows:
Ash 3.93, phosphorus 0.16, potassium 0.69, calcium 0.24, crude
fiber 35.6, ether extract 1.18, nitrogen-free extract 55.91 and
crude protein 3.38 percent.
Immediately after the first crop of Pangola hay was removed
a top-dressing of 200 pounds per acre of nitrate of soda was ap-
plied. The second cutting of hay was made September 26 and
averaged 2.31 tons of barn-dried hay per acre. The chemical
composition of this second cutting was greatly improved, prob-
ably' due mostly to its stage of growth when cut. Samples taken
from the bales after drying analyzed as follows: Ash 7.20, phos-
phorus 0.43, potassium 1.54, calcium 0.62, crude fiber 33.07, ether
extract 2.42, nitrogen-free extract 50.00 and crude protein 7.31
percent.
A field of Pensacola Bahia supporting a good growth of com-
mon lespedeza was cut for hay on August 8, 1949. This Bahia-
.lespedeza hay was grown on a Leon fine sand which had been
limed and had received annual February application of 500
pounds of 0-10-10 fertilizer per acre. The barn-dried yield of
Bahia-lespedeza hay was 3.5 tons per acre. Only one cutting
was made on this grass-legume mixture, although considerable
growth was available and it could have been cut again on Oc-
tober 1. The chemical composition of this Bahia-lespedeza mix-
ture was as follows: Ash 4.58, phosphorus 0.18, potassium 1.38,
calcium 1.07, crude fiber 32.12, ether extract 2.52, nitrogen-free
extract 49.55 and crude protein 11.22 percent.
Preliminary investigations with sweet yellow lupines and
early Hairy indigo have been started. Sweet yellow lupines cut in
an early bloom stage analyzed from 14.38 to 18.50 percent pro-
tein and yielded 2.5 tons of dry hay per acre. Early Hairy indigo
in the bloom stage analyzed 13.12 to 15.61 percent protein and
yielded 4.2 tons of dry hay per acre from one cutting.
Perennial grasses have the ability to recover and make new
growth after they are cut for hay. Annual grasses may or may








Florida Agricultural Experiment Stations


not recover and annual legumes must be cut at the proper stage
of growth and height to enable the plants to produce good second
growth. Trials to date indicate indigo will die if cut too close
while in the bloom stage. Some leaves should be left on the
stubble part of the plant after the haying operation. Early
mowing of indigo when the plants are six inches to a foot in
height causes the plant to branch out and subsequent mowings
are less harmful. Often two cuttings of indigo hay can be had
from the same planting and occasionally a third cutting is
available.
Protein content is considerably higher in immature than in
mature plants. When Pangola grass, Bahia grass, Hairy indigo
and other crops reach full bloom or seeding stage the feed qual-
ities of the forage are greatly reduced as compared to the same
crop several weeks earlier.
The younger the vegetative growth of plants when cut for
hay the better will be the quality of hay. Inversely, the diffi-
culties of curing and cost will be greater on immature plants.
In an active vegetative state most grasses and legumes will
average 80 to 90 percent water. Mature plants, or those past
the full bloom and freely setting seed, will usually contain 55
percent or less of water.

Estimated Cost of Installing an Artificial Drier
The initial cost of installing a hay drier varies with the size
of the mow floor. The major items needed and their approxi-
mate cost are listed below:
Electric motor (5 h.p.) --...-. ..... $125 to $200
Blower & drive ---~.. ----....-... $170 to $250
Oil burner ........-....__.------.... $150
Heat exchanger ..$...1..------- -..- $100 to $200
Duct & floor --...-...-- ....- $250 to $350
Controls _-... ----_ --.....-......-.. $ 35
Total $830 to $1,185
The average cost of equipment and materials is approximately
75c per square foot of floor area for a medium-size barn. The
cost per square foot for a small barn will be slightly higher.

Cost of Operation
The experimental data in Table 1 indicate that the fuel and
electricity cost for curing a ton of hay is between $3 and $5
per ton. The major factors that cause the drying cost to vary








Florida Agricultural Experiment Stations


not recover and annual legumes must be cut at the proper stage
of growth and height to enable the plants to produce good second
growth. Trials to date indicate indigo will die if cut too close
while in the bloom stage. Some leaves should be left on the
stubble part of the plant after the haying operation. Early
mowing of indigo when the plants are six inches to a foot in
height causes the plant to branch out and subsequent mowings
are less harmful. Often two cuttings of indigo hay can be had
from the same planting and occasionally a third cutting is
available.
Protein content is considerably higher in immature than in
mature plants. When Pangola grass, Bahia grass, Hairy indigo
and other crops reach full bloom or seeding stage the feed qual-
ities of the forage are greatly reduced as compared to the same
crop several weeks earlier.
The younger the vegetative growth of plants when cut for
hay the better will be the quality of hay. Inversely, the diffi-
culties of curing and cost will be greater on immature plants.
In an active vegetative state most grasses and legumes will
average 80 to 90 percent water. Mature plants, or those past
the full bloom and freely setting seed, will usually contain 55
percent or less of water.

Estimated Cost of Installing an Artificial Drier
The initial cost of installing a hay drier varies with the size
of the mow floor. The major items needed and their approxi-
mate cost are listed below:
Electric motor (5 h.p.) --...-. ..... $125 to $200
Blower & drive ---~.. ----....-... $170 to $250
Oil burner ........-....__.------.... $150
Heat exchanger ..$...1..------- -..- $100 to $200
Duct & floor --...-...-- ....- $250 to $350
Controls _-... ----_ --.....-......-.. $ 35
Total $830 to $1,185
The average cost of equipment and materials is approximately
75c per square foot of floor area for a medium-size barn. The
cost per square foot for a small barn will be slightly higher.

Cost of Operation
The experimental data in Table 1 indicate that the fuel and
electricity cost for curing a ton of hay is between $3 and $5
per ton. The major factors that cause the drying cost to vary








Hay and Seed Drying


are: (1) Moisture content' of hay when placed on drier; (2)
weather conditions during the drying period; (3) type of hay
being dried; (4) depth of hay on drier; and (5) whether the
hay is long, chopped or baled.
Of these factors, the most important ones are weather con-
ditions during the drying period and moisture content of the
hay when placed on the drier. When the relative humidity is
high during the drying period, or the moisture content of the
hay is over 50 percent at the time it is placed on the drier, the
drying time is extended, thereby increasing the use of fuel and
electricity.

Farmer Acceptance
There is much interest in hay drying in all sections of the
state. The latest report is that there are approximately 30 slatted
floor hay driers in operation in this state (see Fig. 2). On a
national basis, farmer acceptance is centered mostly in the East
Central part of the United States, with the greatest interest in
Virginia, Tennessee, Ohio, Pennsylvania and North Carolina.

Design of Hay Drier
Building Requirements.-A barn hay drier can be installed
in almost any type of building that does not have too many posts
or supports on the mow floor. Some alterations may have to
be made if a drier is to be installed in a building which is not
specifically designed for that purpose. The strength and sound-
ness of the structural members should be checked, as the weight
of partially cured hay is sometimes twice as heavy as hay that.
is already dry enough for storage.
To calculate the dry hay capacity of a barn, or the size barn
to accommodate a given amount of hay, the following density
per ton should be used:
Baled hay .................... 325 cubic feet per ton
Loose hay ...........--...--- 400 cubic feet per ton
Chopped hay---................ 325 cubic feet per ton.
Roof.-A self-supporting roof is the ideal type of roof for a
hay drying barn. The roof should not leak, as wet spots on the
hay will cause uneven drying and probably molding.
'All references to percent moisture in this bulletin are figured on a
wet basis.








Hay and Seed Drying


are: (1) Moisture content' of hay when placed on drier; (2)
weather conditions during the drying period; (3) type of hay
being dried; (4) depth of hay on drier; and (5) whether the
hay is long, chopped or baled.
Of these factors, the most important ones are weather con-
ditions during the drying period and moisture content of the
hay when placed on the drier. When the relative humidity is
high during the drying period, or the moisture content of the
hay is over 50 percent at the time it is placed on the drier, the
drying time is extended, thereby increasing the use of fuel and
electricity.

Farmer Acceptance
There is much interest in hay drying in all sections of the
state. The latest report is that there are approximately 30 slatted
floor hay driers in operation in this state (see Fig. 2). On a
national basis, farmer acceptance is centered mostly in the East
Central part of the United States, with the greatest interest in
Virginia, Tennessee, Ohio, Pennsylvania and North Carolina.

Design of Hay Drier
Building Requirements.-A barn hay drier can be installed
in almost any type of building that does not have too many posts
or supports on the mow floor. Some alterations may have to
be made if a drier is to be installed in a building which is not
specifically designed for that purpose. The strength and sound-
ness of the structural members should be checked, as the weight
of partially cured hay is sometimes twice as heavy as hay that.
is already dry enough for storage.
To calculate the dry hay capacity of a barn, or the size barn
to accommodate a given amount of hay, the following density
per ton should be used:
Baled hay .................... 325 cubic feet per ton
Loose hay ...........--...--- 400 cubic feet per ton
Chopped hay---................ 325 cubic feet per ton.
Roof.-A self-supporting roof is the ideal type of roof for a
hay drying barn. The roof should not leak, as wet spots on the
hay will cause uneven drying and probably molding.
'All references to percent moisture in this bulletin are figured on a
wet basis.











0




TABLE 1.-SAMPLES OF DATA TAKEN ON THE OPERATION OF EXPERIMENTAL DRIER LOCATED IN GAINESVILLE REGARDING COST OF DRY-

ING, AMOUNTS OF AIR, TEMPERATURE AND MOISTURE CONTENTS. .


Moist. Cont. Moist. Cont. Lbs. Hours Cost z
When Placed When Removed Cured Cfm per Drying per
Crop Form on Drier from Drier Hay Sq. Ft. Temp. Rise Gals. Fuel Kwh Elec. Time Ton 1o

Hairy Indigo Baled (round) 49.8% 20.2% 6,490 18 35'F. 79 81 99 $3.86
Hairy Indigo Baled (round) 51.0% 19.0% 5,435 22 22F. 52 99 124 $3.77
Pangola Baled (round) 56.0% 18.0% 5,145 23 29F. 69 82 111 $4.72 ^
Pangola Baled (square) 46.0% 18.0% 14,700 23.8 30F. 80 628 146- $3.86
Lespedeza-
Bahia Mix Baled (square) 49.0% 16.4% 16,350 24.1 31*F. 200 467 108 $4.41
Pangola Baled (square) 45.5% 17.0% -14,720 23.9 19F 108 424 97 $3.34
Pangola and
Hairy Indigo Baled (square) 49.3% 15.4% 12,870 24.0 20F. 100 438 103 $3.60 .







Hay and Seed Drying


Ventilation of Mow.-Adequate ventilation of the mow above
the hay line is essential. Ventilation must be sufficient to permit
the moist air which passes out of the hay to move away from
the hay; otherwise, moisture may condense on the roof and fall
on the hay (see Fig. 3).
It is best to have cross ventilation to move the moist air out
of the building. Two or three feet of hardware cloth around the
sides of the building next to the rafters would be satisfactory.
However, doors, windows and roof ventilators will usually prove
sufficient. The combined area of all openings should be at least
one square foot per 200 cubic feet per minute of air delivered
by the fan (6)2.
Mow Floor.-The mow floor should be as nearly air-tight as
possible. If the floor has air leaks, air which should have been
forced through the hay will be lost through the floor. When
heated air is used it does not take much air leakage to increase
greatly the cost of drying. A well-laid tongue-and-groove floor
or a double floor of rough or dressed boards with building paper

Italic figures in parentheses refer to Literature Cited.

Fig. 2.-Hay and seed drier built and operated by the Soil Conserva-
tion District at Lake City, Florida. This drier will hold approximately
40 tons of hay or 50,000 pounds of lupine seed per loading.







Hay and Seed Drying


Ventilation of Mow.-Adequate ventilation of the mow above
the hay line is essential. Ventilation must be sufficient to permit
the moist air which passes out of the hay to move away from
the hay; otherwise, moisture may condense on the roof and fall
on the hay (see Fig. 3).
It is best to have cross ventilation to move the moist air out
of the building. Two or three feet of hardware cloth around the
sides of the building next to the rafters would be satisfactory.
However, doors, windows and roof ventilators will usually prove
sufficient. The combined area of all openings should be at least
one square foot per 200 cubic feet per minute of air delivered
by the fan (6)2.
Mow Floor.-The mow floor should be as nearly air-tight as
possible. If the floor has air leaks, air which should have been
forced through the hay will be lost through the floor. When
heated air is used it does not take much air leakage to increase
greatly the cost of drying. A well-laid tongue-and-groove floor
or a double floor of rough or dressed boards with building paper

Italic figures in parentheses refer to Literature Cited.

Fig. 2.-Hay and seed drier built and operated by the Soil Conserva-
tion District at Lake City, Florida. This drier will hold approximately
40 tons of hay or 50,000 pounds of lupine seed per loading.







Florida Agricultural Experiment Stations


between is satisfactory. A good sturdy floor with small cracks
may be made air-tight by the use of roofing material put on the
floor in the same manner as it would be placed on a roof. A
concrete floor also is satisfactory.

Hay Track and Fork.-The need for a hay fork and track
is great when handling partially dried long hay with a moisture
content of 35 to 50 percent, which is considerably heavier than
field-dried hay. For uniform drying, it is necessary to place the
hay on the drier uniformly, with as little packing as possible.
The hay fork facilitates this operation. When hay is dried in the
bale the hay track and fork are not necessary. In some cases,
however, a conveyor may prove helpful.

Parts and Functional Uses.-Parts of the hay drier and their
functional uses follow:
A. Mechanical Equipment:
1. Blower or fan-to deliver air under pressure to the
system.
2. Electric motor or gasoline engine-source of power to
operate fan.
3. V-belt drive-to transmit power from motor to fan.
4. Pressure burner (with stack switch)-to supply heat.

Fig. 3.-Barn hay drier at the Agricultural Experiment Station farm.
Note mow ventilators under the eaves and on the roof ridge.

.. 11- V' ,. ---
.-*1. .







Florida Agricultural Experiment Stations


between is satisfactory. A good sturdy floor with small cracks
may be made air-tight by the use of roofing material put on the
floor in the same manner as it would be placed on a roof. A
concrete floor also is satisfactory.

Hay Track and Fork.-The need for a hay fork and track
is great when handling partially dried long hay with a moisture
content of 35 to 50 percent, which is considerably heavier than
field-dried hay. For uniform drying, it is necessary to place the
hay on the drier uniformly, with as little packing as possible.
The hay fork facilitates this operation. When hay is dried in the
bale the hay track and fork are not necessary. In some cases,
however, a conveyor may prove helpful.

Parts and Functional Uses.-Parts of the hay drier and their
functional uses follow:
A. Mechanical Equipment:
1. Blower or fan-to deliver air under pressure to the
system.
2. Electric motor or gasoline engine-source of power to
operate fan.
3. V-belt drive-to transmit power from motor to fan.
4. Pressure burner (with stack switch)-to supply heat.

Fig. 3.-Barn hay drier at the Agricultural Experiment Station farm.
Note mow ventilators under the eaves and on the roof ridge.

.. 11- V' ,. ---
.-*1. .







Hay and Seed Drying


5. Heat exchanger-to exchange the heat from the flame
or burned fuel to the air (see Fig. 4).
6. Controls
(a) Magnetic starter-to protect electric motor.
(b) Humidistat-to turn on heat automatically when
the humidity rises above a set point. The use of
this control is optional.
(c) High limit switch-to cut off the heat if, for
some reason, the fan should stop.
(d) Thermostat-to control temperature of air. This
control is necessary for seed drying but is op-
tional for hay drying.
B. Fan and Heater Room or Shed: To house the fan, heater,
motor and controls. If there is sufficient room in the barn to

Fig. 4.-Heat exchanger which adds heat to the drying air. Note the
smoke stack, center and right, which carries away the products of com-
bustion, thereby reducing the fire hazard.








Florida Agricultural Experiment Stations


house the equipment, and the barn has a concrete floor, the fan
and heater room is not necessary.
C. Slatted Floor: To deliver the air uniformly into the hay.
Types of Air Distribution Systems.-There are numerous
types of air distribution systems. The slatted floor system de-
scribed here is well suited for all-around use. This type of system
is adaptable to both seed and hay drying (6).
The classification and description of main duct arrangements
are listed below:
A. Side Main Duct: The side main duct is located along either
side of the building. In this type of installation, the slatted floor
extends from only one side of the main duct. It costs less to
construct this type of main duct because the wall of the barn
may be used for one side of the duct. If the wall has cracks
through which air will leak, building paper may be used to make
the duct air-tight. The side main duct is not recommended for
buildings with a width of more than 30 feet (see Fig. 5).
B. Center Main Duct: The center main duct is located along
the center axis of either dimension of the barn, depending on
which is the most convenient. The slatted floor extends outward


N SIDE MAIN
DUCT ARRANGEMENT

Fig. 5.-Side main duct arrangement of slatted floor hay drier. This
arrangement is recommended for narrow hay mows.
































CENTER MAIN
DUCT ARRANGEMENT

Fig. 6.-Center main duct arrangement of slatted floor hay drier. This arrangement is recommended for large hay mows.
C1







Florida Agricultural Experiment Stations


from both sides of the main duct. The center main duct is
recommended where both the length and width of the barn
exceed 30 feet. This arrangement is excellent for seed and grain
drying, as the drying floor on one side of the main duct can be
used for drying seed or grain while the other side is being loaded
or unloaded (see Fig. 6). For plans showing more details, see
Figures 28 and 29.
Design of Main Duct.-The size of the main duct is based on
the volume of air delivered by the fan. The main duct should


CALKING


Nl

Fig. 7.-Detailed construction plan for a typical main duct. The
framing is built around the outside of the main duct to reduce friction
loss.








Hay and Seed Drying


never be smaller than the fan opening. Table 2 shows the proper
size main duct for various air deliveries:
TABLE 2.-RECOMMENDED MAIN DUCT SIZES BASED ON VARIOUS Am DELIVERIES
IN CUBIC FEET OF AIR PER MINUTE.
Cu. Ft. of Air Size of Square Cross-section
per Minute Main Duct in Ft. Area Sq. Ft.
0- 6,000 2' x 2' 4
6,000 15,000 3' x 3' 9
15,000 25,000 4' x 4' 16
25,000 40,000 5' x 5' 25
40,000 62,000 6' x 6' 36

Note.-It is not necessary for the main duct to be square. If it is con-
structed in a rectangular shape, however, the wide dimension should be
not more than double the length of the narrow dimension. The cross
sectional area of the main duct should always correspond with the
recommendations above.

Several building materials may be used to fabricate the main
duct. The materials best suited are tongue-and-groove sheathing,
masonite, 1/2-inch plywood and plaster board. Select the mate-
rial that is cheapest in the locality where the hay drier is being
constructed. (See Fig. 7 for construction details.)
It is general practice in many areas to have openings in the
top of the main duct to permit the drying of hay placed over it.
When this is practiced, the size of openings in the main duct
must be adjusted for various depths and varieties of hay in
order to obtain proper air distribution. Because of the compli-
cated nature of these adjustments it is felt that the space over
the main duct should not be used for drying except in special
cases. In some installations it may prove practical to build the
main duct along the outside of the drying barn, thereby utilizing
the entire inside area of the barn for hay or seed drying.

Design of Slatted Floor Distribution System.-The slatted
floor should cover the entire drying floor area; it is recommended
that it be made from 1 x 2 inch rough lumber placed 4 inches on
centers. Thbse slats are supported on rough sawed joists placed
approximately 2 feet on centers. These joists are placed on the
barn floor perpendicular to the long axis of the main duct. The
dimensions of the joist vary as to the length of the joist and
the amount of air delivered. Recommended dimensions are
shown in Table 3.
In order to prevent excess air leakage, it is recommended
that a strip of building paper or lumber, a foot wide, be placed







Florida Agricultural Experiment Stations


TABLE 3.-CHosS-SECTIONAL DIMENSIONS OF SLATTED FLOOR JOIST BASED ON
LENGTH OF JOIST AND AN AIR DELIVERY RATE OF 20 Cu. FT. PER
MINUTE PER SQ. FT. OF DRYIN. AREA.
Length Dimensions of
of Joist Cross-section Amt. of Air
0 22 ft. 2 in. x 6 in. 20 cu. ft. per min. per
sq. ft. of floor area
23 28 ft. 2 in. x 8 in. 20 cu. ft. per min. per
sq. ft. of floor area
29 31 ft. 2 in. x 10 in. 20 cu. ft. per min. per
sq. ft. of floor area
32 36 ft. 2 in. x 12 in. 20 cu. ft. per min. per
sq. ft. of floor area

on the slatted floor adjacent to all vertical walls. This will
prevent air from channeling up the side of a smooth wall.
It is necessary to have access to the mow floor to facilitate
the removal of leaves and small pieces of hay that may fall
through the openings in the slatted floor. It is recommended
that approximately 6 feet of the slatted floor, parallel to the
main duct, be removable. This removable section should be on
the opposite side of the barn from the main duct, as the air
will usually have enough velocity to blow the leaves and small
pieces of hay to the outer side of the slatted floor where they
can be removed easily (see Fig. 8 for details).

Fig. 8.-This removable section of the slatted floor facilitates the re-
moval of hay that falls through cracks in the floor.
*!- *: *- -







Hay and Seed Drying


Selecting Equipment
As a safety precaution, it is suggested that all mechanical
equipment and controls be stamped with the Fire Underwriters'
label of approval. If insurance is to be carried on a drying in-
stallation, it will have to be inspected by the insurer and a
rate established.
Fan.-Factors that govern the fan to be selected for a hay
drier are listed below:
1. The maximum size electric motor that can be operated
from the distribution electric line serving the installation. The
average rural line is limited to 5 h.p. motors or smaller.
2. Volume of air required.
3. Estimated static pressure against which the fan must
work.
4. Velocity of air delivery should be not more than 2,000
feet per minute.
A fan or blower selected must be able to deliver air under
pressure to the slatted floor system. The volume of air delivered
is measured in cubic feet per minute' and is written cfm. The
volume of air delivered varies with the static pressure against
which the fan is working. Performance charts are furnished for
all fans by the manufacturer. These charts show the air delivery
against various static pressures, the horsepower requirement
and the speed at which the fan operates for each set of con-
ditions.
Static pressure is the compressive force of the air exerted
in all directions normal to any surface in contact with the air,
and is measured in inches of water (5). One inch of water static
pressure will elevate a column of water one inch. The greater the
depth and density of the hay the harder it will be for the fan to
force air through the hay and the greater the static pressure
will be. Also the greater the static pressure the greater the
horsepower requirement to deliver a given amount of air.
Volume of Air Needed.-The system should be designed for
approximately 20 cfm of air per square foot of floor area. As an
example, consider a mow floor 20 ft. x 30 ft. The area of the
mow floor will be -20 x 30- 600 square feet. This area (600
sq. ft.) multiplied by 20 cfm would give 12,000 cfm of air for
the fan output.
The horsepower requirement and rpm of fans must be ob-
tained from the performance data chart of each fan. Select a
fan that will deliver 20 cfm of air per square foot of floor aiea







Hay and Seed Drying


Selecting Equipment
As a safety precaution, it is suggested that all mechanical
equipment and controls be stamped with the Fire Underwriters'
label of approval. If insurance is to be carried on a drying in-
stallation, it will have to be inspected by the insurer and a
rate established.
Fan.-Factors that govern the fan to be selected for a hay
drier are listed below:
1. The maximum size electric motor that can be operated
from the distribution electric line serving the installation. The
average rural line is limited to 5 h.p. motors or smaller.
2. Volume of air required.
3. Estimated static pressure against which the fan must
work.
4. Velocity of air delivery should be not more than 2,000
feet per minute.
A fan or blower selected must be able to deliver air under
pressure to the slatted floor system. The volume of air delivered
is measured in cubic feet per minute' and is written cfm. The
volume of air delivered varies with the static pressure against
which the fan is working. Performance charts are furnished for
all fans by the manufacturer. These charts show the air delivery
against various static pressures, the horsepower requirement
and the speed at which the fan operates for each set of con-
ditions.
Static pressure is the compressive force of the air exerted
in all directions normal to any surface in contact with the air,
and is measured in inches of water (5). One inch of water static
pressure will elevate a column of water one inch. The greater the
depth and density of the hay the harder it will be for the fan to
force air through the hay and the greater the static pressure
will be. Also the greater the static pressure the greater the
horsepower requirement to deliver a given amount of air.
Volume of Air Needed.-The system should be designed for
approximately 20 cfm of air per square foot of floor area. As an
example, consider a mow floor 20 ft. x 30 ft. The area of the
mow floor will be -20 x 30- 600 square feet. This area (600
sq. ft.) multiplied by 20 cfm would give 12,000 cfm of air for
the fan output.
The horsepower requirement and rpm of fans must be ob-
tained from the performance data chart of each fan. Select a
fan that will deliver 20 cfm of air per square foot of floor aiea







Florida Agricultural Experiment Stations


working against the static pressure of the system loaded with
hay. The static pressure will vary with the type and depth of
hay on the drier and whether the hay is long, chopped or baled.
Hay with large leaves and small stems will offer more resistance
to air flow than stemmy hay; also, the higher the moisture
content of the hay the greater the resistance to air flow. Hay
of average density offers the following resistance to air flow:
Long hay .--------.............. 8' to 10' depth-static pressure, average- .75 inch
Chopped hay --..----------...... 6' to 8' depth-static pressure, average-1.0 inch
Baled hay (conventional) 6' to 8' depth-static pressure, average-1.0 inch
Types of Fans Suitable for Hay Drying.-Cotton gin fans,
ensilage cutter blowers and common ventilating fans are not
suitable for hay-drying purposes. The following types of fans
have been used successfully for hay drying in this state:
1. Centrifugal blower-forward curved blade
2. Centrifugal blower-backward curved blade
3. Propeller type fan
Characteristics of Fans.-Characteristics of various types of
fans follow.
Centrifugal Blower-Forward Curved Blade.-The forward
curved blade centrifugal blower operates at low speeds with low
air velocities. This class of fan is divided into two general types:
(1) Heavy gauge metal construction with single width and single
inlet or double width and double inlet; (2) light gauge metal
construction with double inlet and single width. Two units may
be mounted on one shaft.
This type of fan is not ideally suited for hay drying because
of an overloading characteristic which may cause the motor
driving the fan to overload. The performance curve for this
type fan indicates that the maximum h.p. is required when
operating at free delivery. As the pressure builds up, or the
depth of hay on the drier increases, the h.p. requirement de-
creases. This means that if a hay drier is designed for 10 feet
of average type long hay or a static pressure of 0.75 inches of
water, and only 6 feet of stemmy hay that offered a static pres-
sure resistance of 0.4 inches of water is placed on the drier the
motor would be overloaded due to the increased h.p. required
to operate the fan. This characteristic is particularly undesir-
able when the hay drier may be used for other purposes such
as seed and grain drying.
The static pressure on this type of fan may be controlled







Florida Agricultural Experiment Stations


working against the static pressure of the system loaded with
hay. The static pressure will vary with the type and depth of
hay on the drier and whether the hay is long, chopped or baled.
Hay with large leaves and small stems will offer more resistance
to air flow than stemmy hay; also, the higher the moisture
content of the hay the greater the resistance to air flow. Hay
of average density offers the following resistance to air flow:
Long hay .--------.............. 8' to 10' depth-static pressure, average- .75 inch
Chopped hay --..----------...... 6' to 8' depth-static pressure, average-1.0 inch
Baled hay (conventional) 6' to 8' depth-static pressure, average-1.0 inch
Types of Fans Suitable for Hay Drying.-Cotton gin fans,
ensilage cutter blowers and common ventilating fans are not
suitable for hay-drying purposes. The following types of fans
have been used successfully for hay drying in this state:
1. Centrifugal blower-forward curved blade
2. Centrifugal blower-backward curved blade
3. Propeller type fan
Characteristics of Fans.-Characteristics of various types of
fans follow.
Centrifugal Blower-Forward Curved Blade.-The forward
curved blade centrifugal blower operates at low speeds with low
air velocities. This class of fan is divided into two general types:
(1) Heavy gauge metal construction with single width and single
inlet or double width and double inlet; (2) light gauge metal
construction with double inlet and single width. Two units may
be mounted on one shaft.
This type of fan is not ideally suited for hay drying because
of an overloading characteristic which may cause the motor
driving the fan to overload. The performance curve for this
type fan indicates that the maximum h.p. is required when
operating at free delivery. As the pressure builds up, or the
depth of hay on the drier increases, the h.p. requirement de-
creases. This means that if a hay drier is designed for 10 feet
of average type long hay or a static pressure of 0.75 inches of
water, and only 6 feet of stemmy hay that offered a static pres-
sure resistance of 0.4 inches of water is placed on the drier the
motor would be overloaded due to the increased h.p. required
to operate the fan. This characteristic is particularly undesir-
able when the hay drier may be used for other purposes such
as seed and grain drying.
The static pressure on this type of fan may be controlled







Hay and Seed Drying


by the use of an adjustable damper played in the fan outlet. This
will keep the motor from overloading but will reduce the amount
of air output and the fan efficiency.
Centrifugal Blower-Backward Curved Blade.-This type of
fan is superior to the forward curved blade for hay drying and
seed drying, due to its non-overloading characteristics. It oper-
ates at a higher speed than a forward curved blade fan of the
same capacity. Because of its high speed a stronger and more
rigid frame and housing is required. This, in turn, makes the
cost of this type fan higher than the forward curved blade type.
This fan has the ability to deliver air against high or low
static pressures without overloading the motor. If static pres-
sures higher than 1.5 inches of water are expected it is recom-
mended that this type of fan be used.
Propeller Type Fan-The propeller type fan is suitable for
hay drying purposes. The major advantages of this type fan
are: It is light in weight, compact, requiring little space for
installation, and low in cost.
Disadvantages of this type of fan are that it is noisy and
not suited for operations where exceedingly high static pressures
are encountered. For installations where less than 1.5 inches of
water static pressure is expected, a propeller type fan is usually
satisfactory.

Sources of Power to Operate Fan
The most convenient and dependable source of power is the
electric motor. On farms where electricity is not available, an
internal combustion engine may be used. Electric motors are
easier to install in conjunction with an automatic safety control
system.
Electric Motor.-The electric motor must be of sufficient size
to operate the fan selected. The motor size may be limited, by
the type of electric service available. Most single phase lines are
limited to 5 horsepower, especially in rural areas. Repulsion-
induction motors are preferable in hay drying installation. How-
ever, a capacitor motor may be used if it is already available for
other uses on the farm.
Internal Combustion Engine.-If electricity is not available,
the use of an internal combustion engine as a source of power is
satisfactory, even though it is considered to be an added fire
hazard. Caution should be taken when handling fuel around the








Florida Agricultural Experiment Stations


engine. It is recommended that the engine not be placed in a
position where the fan intake will pull air over or around the
engine.

Drive
The most desirable drive for hay driers is a short center
V-belt drive. Flat pulleys are not recommended because belts
are more likely to run off this type' pulley.
Pulley Size.-The drive and driven pulley size should be
selected very carefully in order that the fan will operate at the
correct speed. Standard "A-B" V-pulleys with composite grooves
are designed to accommodate either "A" or "B" cross-section
V-belts. The "A" belts ride slightly below the top of the pulley
grooves; the "B" belts approximately flush. The pitch diameter
therefore is larger when using "B" section belts than with "A"
section belts. For this reason, it is necessary when selecting the
proper size pulley to consider the pitch diameter corresponding
to the type of V-belt to be used.
Center distance between pulleys should not exceed 2/2 to 3
times the sum of the pulley diameters, nor should it be less
than the diameter of the larger pulley.
Belts.-The number and size of V-belts for a hay drying
installation are listed below:
3 hp motor-1 "B" section belt or 2 "A" section belts
5 hp motor-2 "B" section belts
71/A hp motor-3 "B" section belts.

Supplemental Heat
In Florida, because of the high relative humidity which pre-
vails during the summer months, the use of supplemental heat
is required to successfully dry hay in the barn. Supplemental
heat increases the moisture-holding capacity of air (2).
The following advantages are realized when supplemental
heat is used in a hay drying installation:
1. Shortens the drying time and thus enables more dryings
during the hay making season.
2. Makes the hay drier suitable for grain and seed drying.
3. Produces high quality hay during unfavorable weather
conditions.
4. Increases the hours per day of effective drying.








Florida Agricultural Experiment Stations


engine. It is recommended that the engine not be placed in a
position where the fan intake will pull air over or around the
engine.

Drive
The most desirable drive for hay driers is a short center
V-belt drive. Flat pulleys are not recommended because belts
are more likely to run off this type' pulley.
Pulley Size.-The drive and driven pulley size should be
selected very carefully in order that the fan will operate at the
correct speed. Standard "A-B" V-pulleys with composite grooves
are designed to accommodate either "A" or "B" cross-section
V-belts. The "A" belts ride slightly below the top of the pulley
grooves; the "B" belts approximately flush. The pitch diameter
therefore is larger when using "B" section belts than with "A"
section belts. For this reason, it is necessary when selecting the
proper size pulley to consider the pitch diameter corresponding
to the type of V-belt to be used.
Center distance between pulleys should not exceed 2/2 to 3
times the sum of the pulley diameters, nor should it be less
than the diameter of the larger pulley.
Belts.-The number and size of V-belts for a hay drying
installation are listed below:
3 hp motor-1 "B" section belt or 2 "A" section belts
5 hp motor-2 "B" section belts
71/A hp motor-3 "B" section belts.

Supplemental Heat
In Florida, because of the high relative humidity which pre-
vails during the summer months, the use of supplemental heat
is required to successfully dry hay in the barn. Supplemental
heat increases the moisture-holding capacity of air (2).
The following advantages are realized when supplemental
heat is used in a hay drying installation:
1. Shortens the drying time and thus enables more dryings
during the hay making season.
2. Makes the hay drier suitable for grain and seed drying.
3. Produces high quality hay during unfavorable weather
conditions.
4. Increases the hours per day of effective drying.







Hay and Seed Drying


The use of supplemental heat in a hay drying installation
has some disadvantages, the major ones being increased fire
hazard and increased installating and operating costs.
Amount of Heat Required.-Results of research at the Florida
Agricultural Experiment Station indicate that a good rate of
drying can be obtained by increasing the temperature of the
drying air approximately 20 F. above the outside air when air
is forced through the hay at a rate of 20 cfm per sq. ft. of
slatted floor area. On the basis of results to date, this amount
of heat gives the greatest drying efficiency. The drying time may
be shortened by increasing the drying air temperature, but the
initial cost of equipment and the operating cost will be in-
creased (4). The temperature may be increased as much as 50 F.
without damaging the hay or equipment if the equipment is
properly selected and installed.
The addition of heat to air increases the moisture-absorbing

Fig. 9.-Heat exchanger made of corrugated stainless steel.


A


J?

*> y,







Florida Agricultural Experiment Stations


capacity of air and the addition of heat to the hay increases
the vapor pressure of the moisture in the hay. By increasing
the vapor pressure of the moisture within the hay the tendency
of this moisture to vaporize is increased (3).
The following is an example of how much the addition of
heat to air increases the moisture-absorbing capacity of air.
Air at 850 F. and 90% relative humidity contains 0.00165 pounds
of moisture per cubic foot. When saturated, this air will contain
0.00185 pounds of moisture per cubic foot, or an increase of
0.00020 pounds. If the temperature of this air is raised 200 F.
(to 1050 F.) the relative humidity will be reduced to approxi-
mately 50%, but it will still contain 0.00165 pounds of moisture
per cubic foot. This heated air has a capacity of absorbing
0.00335 pounds of moisture per cubic foot of air (.00335 minus
.00165), or 0.00170 pounds per cubic foot (750%) more than
the unheated air. However, except at the beginning of the drying
period, the air leaving the hay will not be saturated (100%
relative humidity), so the full absorptive capacity of the air
is not utilized. The air usually leaves the hay at an average
relative humidity of 85%. On this basis, entering air at 105 F.
has the ability to absorb (.00283 minus .00165) 0.00118 pounds
per cubic foot, as against a net loss of (.00157 minus .00165)
0.00008 pounds per cubic foot of unheated air. In other words,
hay would take on moisture, if being dried with unheated air
under this set of conditions, instead of releasing moisture:
Sources of Supplemental Heat.-Considering the cost of
fuels in most Florida localities, the most economical method of
heating air is the hot air furnace, burning fuel oil. A heat
exchanger (see Fig. 9) equipped with a pressure oil burner is
probably the most satisfactory type of hot air furnace to install.
It is recommended that the heat exchanger be made of stainless
steel to prevent burning out and corrosion. It is not recommended
that a heating arrangement be used whereby the open flame
comes in contact with the air that is being forced through the
hay. This type of heating arrangement adds to the fire hazard.
Type of Burner.-A pressure type oil burner is recommended
for hay drying installation (see Fig. 10). Most burners have a
capacity range that covers 2 to 5 gallons per hour. When select-
ing the proper size nozzle for a particular installation, be sure
the size is included in capacity range of the burner.
Selection of Burner Size.-The size of burner can be deter-
mined after the amount of air to be heated and the desired








Hay and Seed Drying


temperature rise have been established. The following example
illustrates a method of determining the approximate size of
burner needed.
Equation:
cfm x 60 x Temperature Rise = gph
55 x Efficiency x 138,000
cfm = Cubic feet of air per minute delivered by the fan
when the hay drier is loaded
60 = Minutes per hour
Temperature Rise = Desired temperature rise in degrees Fahrenheit
(20 F. recommended for hay)
55 = The approximate cubic feet of air that can be
raised 1 F. with the use of 1 Btu (heat unit)
Efficiency = The efficiency of this type of heat exchanger will
vary between 70% and 85%
138,000 = Average Btu value of 1 gallon of #2 fuel oil

Fig. 10.-A domestic type pressure oil burner installed in a hay drying
barn located on the Agricultural Experiment Station farm. This is an
experimental arrangement where air is being pulled over the heat ex-
changer. See recommended arrangement in Fig. 11.


'1)








Florida Agricultural Experiment Stations

Problem = How many gallons of #2 fuel oil must be burned per
hour to raise the temperature of 20,000 cfm 20 F.?
Assume an overall efficiency of the heat exchanger is
75%.
20,000 x 60 x 20 = 4.22 gallons per hour
55 x .75 x 138,000


Fig. 11.-Plan of air heater showing details of construction, firebox
dimensions and burner size selection chart. Note the position of the
heater relative to the fan or blower. Direction of air travel is from the fan
toward the heater. See Tables 3 and 4 for air heater dimensions and stack
sizes.








Hay and Seed Drying


Design of Air Heater
The amount of 24-gauge stainless steel surface required to
transmit the heat produced by burning one gallon of oil per
hour is approximately 20 square feet for the type of heat ex-
changer shown in Fig 10, 40 square feet for two gallons per
hour, etc. If a farm is not equipped to make this heater, a
commercial heat exchanger may be purchased. Almost every
sheet metal shop is equipped to make this type of heater.
The plan for the air heater (Fig. 11) does not show specific
dimensions of the heat exchanger or the wall which channels
the air around the heat exchanger. Table 4, showing heat
exchanger dimensions, is for suggestive purposes and not a
definite recommendation. If the heater has the necessary heating
surface (20 square feet per gallon of fuel burned per hour) the
shape is not too important. It must be large enough to accom-
modate the proper size firebox. Should it be necessary to put
the heater in a limited space, the walls of the heater may be
made of corrugated metal or radiating fins may be welded on
the outside.
Heaters burning more than 5 gallons per hour of fuel should
have some steel bars welded across the angle iron frame to give
more strength and to prevent excessive buckling of the stainless
steel heating surfaces.
The distance between the heater and the walls, top and floor
of the duct that channels the air close to the heater should be
such that the velocity of the air passing the heater is 2,000 feet
per minute.
As an example, the distance between the walls, top and floor
of the channeling duct, and a heater that is 40 inches wide and

TABLE 4.-SUGGESTED DIMENSIONS FOR Am HEATERS
BASED ON FUEL OIL CONSUMPTION IN
GALLONS PER HOUR.
Width Depth Length
1 gph 20% 32 23 in.
2 gph 22% 32 43 in.
3 gph 25 39 60 in.
4 gph 30 39 60 in.
5 gph 30 44 60 in.
6 gph 40 48 60 in.
7 gph 40 60 64 in.
8 gph 44 60 72 in.
9 gph 48 60 76 in.
10 gph 48 60 96 in.







Florida Agricultural Experiment Stations


48 inches high over which 20,000 cfm of air is drawn should be
approximately 7 inches.
In most installations it is preferable to locate the heater in
the center of the air stream between the fan and the main duct.
Locate the burner outside the chanelling duct in order that it
will be easily accessible for adjustment.

Chimney
The chimney, or stack, should be of sufficient size and height
to give the proper draft for good combustion. The height of the
stack should be of such length that it will extend above all
objects within 30 feet. A heavy gauge galvanized iron stack
may be used. Minimum size stacks recommended for various
capacities of oil are given in Table 5. A draft regulator placed
in the stack will assist greatly in adjusting the burner.

TABLE 5.-RECOMMENDED STACK SIZES BASED ON FUEL
OIL CONSUMPTION IN GALLONS PER HOUR.
1 gallon per hour 9" diameter
2 gallons per hour 10" diameter
3 gallons per hour 11" diameter
4 gallons per hour 12" diameter
5 gallons per hour 13" diameter
6 gallons per hour 15" diameter
7 gallons per hour 18" diameter
8 gallons per hour 18" diameter
9 gallons per hour 22" diameter
10 gallons per hour 22" diameter

In order to get best results, a heating engineer should be
employed to-adjust the burner after it has been installed.

Portable Driers

Some manufacturers are building portable driers which are
being sold in Florida. The Agricultural Experiment Station has
not tested any portable driers and cannot make a direct state-
ment as to the worth of this type of drier when used under
Florida conditions. A few portable driers, forced air and drum
type, have been installed in this State and are being used for
seed and hay drying purposes.
A'prospective purchaser of a portable drier should be certain
that the unit selected has sufficient capacity to satisfy his needs.
Some manufacturers rate the capacity of their driers in tons of







Florida Agricultural Experiment Stations


48 inches high over which 20,000 cfm of air is drawn should be
approximately 7 inches.
In most installations it is preferable to locate the heater in
the center of the air stream between the fan and the main duct.
Locate the burner outside the chanelling duct in order that it
will be easily accessible for adjustment.

Chimney
The chimney, or stack, should be of sufficient size and height
to give the proper draft for good combustion. The height of the
stack should be of such length that it will extend above all
objects within 30 feet. A heavy gauge galvanized iron stack
may be used. Minimum size stacks recommended for various
capacities of oil are given in Table 5. A draft regulator placed
in the stack will assist greatly in adjusting the burner.

TABLE 5.-RECOMMENDED STACK SIZES BASED ON FUEL
OIL CONSUMPTION IN GALLONS PER HOUR.
1 gallon per hour 9" diameter
2 gallons per hour 10" diameter
3 gallons per hour 11" diameter
4 gallons per hour 12" diameter
5 gallons per hour 13" diameter
6 gallons per hour 15" diameter
7 gallons per hour 18" diameter
8 gallons per hour 18" diameter
9 gallons per hour 22" diameter
10 gallons per hour 22" diameter

In order to get best results, a heating engineer should be
employed to-adjust the burner after it has been installed.

Portable Driers

Some manufacturers are building portable driers which are
being sold in Florida. The Agricultural Experiment Station has
not tested any portable driers and cannot make a direct state-
ment as to the worth of this type of drier when used under
Florida conditions. A few portable driers, forced air and drum
type, have been installed in this State and are being used for
seed and hay drying purposes.
A'prospective purchaser of a portable drier should be certain
that the unit selected has sufficient capacity to satisfy his needs.
Some manufacturers rate the capacity of their driers in tons of







Hay and Seed Drying


hay that can be dried per day. Be wary of these ratings, as they
may be based on drying alfalfa (which is easier to dry than most
Florida hay crops) in states that are less humid than Florida.

Field Preparation and Curing Methods
The moisture content of hay to be cured on the barn drier
should be reduced to at least 50% for long hay, and 35-45% for
baled hay, by field drying before it is placed in the curing barn.
The day selected for cutting the hay should be as dry as pos-
sible. Do not select a day following a heavy rainfall for mowing
hay, as the air and soil will be damp, thus reducing the rate of
field drying. A day when the sun is shining and the relative
humidity is low is ideal for cutting, as the hay will lose much
of its moisture in a short period of field drying.
Hay should be mowed in the morning after the dew or surface
moisture has evaporated and should be permitted to dry in the
swath for about three hours. Then it should be windrowed (see
Fig. 12). After drying in the windows for another two hours,
more or less, the hay can be baled (Fig. 13) and/or hauled to
the hay barn. If the day is partly cloudy and field drying con-

Fig. 12.-A portable drier that is being manufactured and sold in
Florida.







Florida Agricultural Experiment Stations


editions are poor the hay should be dried in the swath until im-
mediately before baling or loading before it is windrowed. If
four or five hours of field drying is not enough to reduce suffi-
ciently the moisture content, the field drying period should be
extended as long as is necessary. Do not permit the moisture
content of the hay, while field drying, to drop below 35%c, as
the quality of the hay will be lowered, due to bleaching and
shattering of leaves.
Figures 14, 15 and 16 show data taken on rates of field
drying for several hay crops under various weather conditions.
Also one set of graphs (Fig. 17) shows a comparison of rates of
field drying between crushed and uncrushed forage.
Hay should be baled as loosely as possible in order that proper
air circulation through the bale can be obtained, but tight enough
to facilitate handling of the bales without breaking when dry (1).
Hay that is baled too tightly will be more difficult to dry, as the
air will move around the bale instead of through it. This will
mean additional drying cost and perhaps mold damage in the
middle of the bale. Baled hay should be hauled to the curing
barn within two hours after it is baled, placed on the drier and
the blower turned on. Baled hay will begin heating very quickly
and will lose quality if permitted to go through a heat.


Fig. 13.-Baling Pangola grass hays with a pick-up baler.







Hay and Seed Drying


CROP, Hairy Indigo
WEATHER CONDITIONS: Fair all day. No clouds.


Inn


I




E 5





0
pi
1^1o
iZ'
*):


A.M.


P.M.


A IA I3 9


CROP: Hairy Indigo.
WEATHER CONDITIONS: Portly cloudy in the
morning. Cloudy in the afternoon.


A.M.


10(


3:0

cc 2


RPM.
ID


Fig. 14.-Graphs showing rate of field drying for Hairy Indigo during
the first four to six hours after cutting, as affected by temperature and
relative humidity of the air (time vs. percent moisture).


A I n__ ___






2 i____ 'V... ______
3f






0


w- -r



/
r,.



0


v


"t







32 Florida Agricultural Experiment Stations
CROP: Cowpeas
WEATHER CONDITIONS: Fair all day, no clouds.


100


A.M.
8 10


P.M.
12 2


CROP: Swe
WEATHER


8et


Yellow Lupine.


CONDITIONS: Fair to partly cloudy.


A.M.


=_
E




I 2
*x^ >


100


80


60


40


P M.


Fig. 15.-Graphs showing rate of field drying for cowpeas and sweet
yellow lupine during the first four to six hours after cutting, as affected
by temperatfife and relative humidity of the air (time vs. percent moist-
ure).


0 _ _


0 _ _


8 10 12 2 4

. .._ ______ _______ _______ ~ _.. .


LV' -"







Hay and Seed Drying


CROP: Pangola Grass
WEATHER CONDITIONS: Fair all day, no clouds.


IOC


80


60


40


20


A.M.
8 10


P.M.
2


CROP: Pangolo Grass
WEATHER CONDITIONS: Fair


E


A.M.
10


all day, no clouds.


P.M.


Fig. 16.-Graphs showing rate of field drying for Pangola grass during
the first four to six hours after cutting, as affected by temperature and
relative humidity of the air (time vs. percent moisture).


8'N


)







Florida Agricultural Experiment Stations


CROPi Hairy Indigo
WEATHER CONDITIONS: Fair in


the morning. Partly


cloudy in the


100


80


afternoon,
A.M.
8 10


P.M.
2


t I I r


60


40 __


20


CROP: Pangola Grass
WEATHER CONDITIONS:
cloudy in the afternoon.

A. h


100


80


60


40


20


Fair in the morning. Partly


1. R M.


It 120 0


Fig. 17.-Graphs comparing the field drying rate of crushed and un-
crushed Pangola grass and Hairy indigo (time vs. percent moisture).


S IV IA 1 & -r




N
*

Ns







Hay and Seed Drying


The amount of hay that can be handled in one day should
be cut each day and this should be enough to cover the entire
drying floor with at least one layer of baled hay. If equipment
and labor are not available to fill the barn the first day filling
may be completed the next day. If the barn is not filled in one
day start drying the hay that is in the barn immediately after
it is loaded into the barn. The cost of drying a barn of hay that is
filled over a two or three-day period is approximately the same
as for a barn that is filled in one day.
When placing loose hay on the drier take care to place it at a
uniform depth over the entire drying floor. Walking on and
packing the hay should be held to a minimum. When placing
baled hay on the drier it is important to fit the bales as closely
together as possible. Stack rectangular bales so that the bales in
every layer will be across the layer of bales below. Round bales
should be stacked so that the long axis of all the bales are
parallel.
After the drier has been loaded, the top layer should be
checked for air leaks. If any leaks are found, break open a few
bales and pack loose hay into the cracks until the air leakage
has stopped. If these air leaks are not closed the static pressure
on the system will drop and the amount of air passing through
hay inside of the bales will be greatly reduced.
To obtain greatest efficiency, heated air should not be used
during the entire drying period. Heat should be used' only at
night and during periods of daylight when the relative humidity
is high. Tests have shown that when the relative humidity is
70% or less, considerable drying can be expected with unheated
air. A humidistat may be placed in the burner circuit which will
automatically turn on the heat when the relative humidity is
above the set point and turn off the heat when the relative
humidity drops below the set point (70%). If for some reason
it is necessary to complete the drying in the shortest possible
time, heat may be used during the entire drying period. When
weather conditions are average it takes from four to six days
to dry a barn of hay.
The simplest method of determining when the hay is dry
enough for safe storage is to examine the top layer of hay to
a depth of 12 inches. If this layer of hay feels sufficiently dry,
the drier should be turned off for a period of 24 hours; then the
blower should be started again and the top layers examined to
determine whether or not the hay is starting to heat. If any








Florida Agricultural Experiment Stations


heating is detected, the hay is not dry enough for storage and
the drying operation should be continued. If no heat is detected
the hay is dry enough for permanent storage.
If moisture testing equipment is available the hay should
be reduced to 20% moisture (wet basis). The sample of hay to
be tested should be taken from the top 12-inch layer.


Seed Drying

The slatted floor hay drier is adaptable for use as a seed or
grain drier.
Seed drying experiments conducted with the hay drier located
on the Agricultural Experiment Station at Gainesville indicate
that a satisfactory seed drying operation may be expected (see
Table 6).

TABLE 6.-SAMPLES OF DATA TAKEN ON COST, RATES OF AIR FLOW, DRYING TIME
AND MOISTURE CONTENT WHILE DRYING LUPINE AND
HAIRY INDIGO SEED.
Cost of Fuel & Moisture
Electricity for Average Moisture Con-
Amount Drying 100 Lbs. Rate Drying Temp. Content- tent-
Seed (dry) of Dry Seed cf Air Time Increase Beginning End
Sweet yel-
low lupine 4500 lbs. $ .131/2 55 cfm 18 hrs. 20 F. 25% 11%
Bitter blue
lupine ,5686 lbs. $ .07 45 cfm 16 hrs. 21 F. 17% 11%
Bitter blue
lupine 4880 lbs. $ .06 35 cfm 18 hrs. 28 F. 17% 10.6%
*Hairy
indigo 700 lbs. $1.58 35 cfm 31 hrs. 30 F. -

The seed pods were harvested with a combine. Approximately 50%
of the seed pods were green. After the pods were dry they were run
through the combine again to remove the seed from the pods. The weight
of the seed in the pods before drying was approximately 4,000 pounds.

It is unlikely that a farmer would wish to dry in one batch
enough seed or grain to cover a floor large enough to dry 20 to
30 tons of hay. The amount of air to be used will vary according
to type of seed to be dried and depth of seed on the drier. No
conclusive data are available as to the proper amount of air to
use for greatest efficiency. Until such information is available
it is recommended that approximately 35 to 40 cubic feet per
minute per square foot of drying floor be used when drying
seed or grain.
Since a hay drier is designed for a delivery of 20 cfm of air
per square foot of drying floor, it is recommended that gates be







Hay and Seed Drying


placed in the main duct to limit the air flow to approximately
one-half of the drying floor (see Fig. 18). This will give an air
delivery of approximately 40 cfm per sq. ft. of drying floor,
which is the recommended amount for seed.
Temperature of the drying air should not exceed a maximum
of 115' F. if the grain is to be used for seed.
Seed may be dried in bags or placed on hardware cloth or
screen wire laid over the slatted floor and dried in bulk. Con-
sidering the additional labor involved when drying seed in bulk,
it is probably better to dry seed in the bag. When drying seed
in the bag it is recommended that the bag be about 75% full
in order that it can be flattened out to make a more uniform
layer of seed over the drier floor (Fig. 19). Any openings be-
tween bags through which air can escape should be filled with
empty bags.

Fig. 18.-Photograph taken inside a main duct. Note the gate and
the grooves for additional gates which may be used to limit the flow of
air to any portion of the drying floor.







Florida Agricultural Experiment Stations


According to data given in Table 7, seed should be placed
over the drying floor in the following depths (maximum), when
the drier described in this bulletin is used. These depths of seed
will give the drying system a static pressure of approximately
1 inch of water.

TABLE 7.-SEED SHOULD BE PLACED IN THE FOLLOWING DEPTHS
MAXIMUMM) WHEN SEED DRYING Is TO BE DONE WITH
ORDINARY HAY DRYING EQUIPMENT.

Depth
Seed Seed in Bag Loose Seed
Hairy Indigo 1 bag 8 inches
Peanuts (for oil) 6 bags 6 feet
Peanuts (for seed) 3 bags 2/2 feet
Pensacola Bahia /z bag 4 inches
Lupine 4 bags 4 feet

Note.-The depth per bag is approximately 10 inches.

Fig. 19.-A method that may be used when placing bags of seed over
the slatted floor.

RIn.








Hay and Seed Drying 39

Figures 20 through 27 show the amount of air that will flow
through depths of seeds when various air pressures are exerted.


.o01 0t .o3 .4.0 .3 .2 -3 -4 I Z 4 5 o
AIR PRESSURE (INCHES WATER)
Fig. 20.-Resistance of bagged blue lupine seed, bin walls and floor
(1/8" mesh hardware cloth) to air flow.


.01 03 .04.o05 .1 .2 *3 .4 .5 / z j > to
AIR PRESSURE (INCHES WATER)
Fig. 21.-Resistance of loose blue lupine seed, bin walls and floor (/s"
mesh hardware cloth) to air flow.








Florida Agricultural Experiment Stations


Fig. 22.-Resistance of bagged Hairy indigo seed, bin walls and floor
(10 mesh screen wire) to air flow.


.01 .u *. .o .I +. ... *s 3 4- b to
AIR PRESSURE (INCHES WATER)
Fig. 23.-Resistance of loose Hairy indigo seed, bin walls and floor
(10 mesh screen wire) to air flow.








Hay and Seed Drying


F.. I I

C,





NO
140---------^- ,--- ---- --__-






NO TE 11 7 PER 1AG /
g3 ---- _^ .--- --- ---- -. -


I.0 .-0 .03 04.0 .1 I 4 1 0 _
AI/ PRESSURE INCHES S WA TER)
Fig. 24.-Resistance of bagged peanuts, bin walls and floor (/4" mesh
hardware cloth) to air flow.



^'i- LL


11_ I I I 11II I I It 11111 I___
.0A .0 -0 .04.05 .1 .3 .4.5 1 :'
AIR PRESSURE (INCHES WATER)


Fig. 25.-Resistance of loose peanuts, bin walls and floor (/4" mesh
hardware cloth) to air flow.


4 s









Florida Agricultural Experiment Stations


VNOTE- DPT R DA /





4:
U'4. ---- --_ --- --- -- -- -^ __





-- --- 7 r

'"2 v r -r nz QAG 10, -/


AIR PRESSURE (INCHES WATER)

Fig. 26.-Resistance of bagged Pensacola Bkhia grass seed, bin
and floor (10 mesh screen wire) to air flow.


walls


o ,___ /-/ -*" .-

S40








-/ /


_.02 .03 PI-W
ai /
/ I/ /









01/ .02 .03 '04^. AIR PRESSURE (INCHES WATER)

Fig. 27.-Resistance of loose Pensacola Bahia grass seed, bin walls and
floor (10 mesh screen wire) to air flow.


1At --












-D-
FN OU L r




WNn WALL





MATERIAL












SLATTED RiR
tEARr OD.C.




BANFLOOR








Florida Agricultural Experiment Stations


TABLE 8.-DIMENSIONS OF MAIN DUCT TO ACCOMPANY CONSTRUCTION
PLAN FOR SIDE MAIN DUCT ARRANGEMENT (FIG. 28).


Cubic Feet of
Air per Minute
Delivered by
the Fan
0 6,000
6,000 15,000
15,000 25,000
25,000 40,000
40,000 62,000


C D E F G H


Depends
on
Fan
Openings


Note-Dimension "B" is based on air delivery or barn size.


TABLE 9.-DIMENSIONS OF SLATTED FLOOR JOISTS TO ACCOMPANY CONSTRUCTION
PLAN FOR SIDE MAIN DUCT ARRANGEMENT (FIG. 28).

Cross-Section
A Dimensions of
Floor Joist
0 22' 2" x 6"
23' 28' 2" x 8"
29' 31' 2" x 10"
32' 36' 2" x 12"



TABLE 10.-DIMENSIONS OF MAIN DUCT TO ACCOMPANY CONSTRUCTION
PLAN FOR CENTER MAIN DUCT ARRANGEMENT (FIG. 29.)


Cubic Feet of
Air per Minute
Delivered by
the Fan
0 6,000
6,000 15,000
15,000 25,000
25,000 40,000
40,000 62,000


C D E F G H


2' 4'
2' 4'
2' 4'
2' -4'
2' -4'


2' Depends
2' on
2' Fan
2' Openings
2'


Note-Dimension "B" is based on air delivery or barn size.


TABLE 11.-DIMENSIONS OF SLATTED FLOOR JOISTS TO ACCOMPANY CONSTRUCTION
PLAN FOR CENTER MAIN DUCT ARRANGEMENT (FIG. 29).

Cross-Section
A Dimensions of
Floor Joist
0 -22' 2" x 6"
23' 28' 2" x 8"
29' 31' 2" x 10"
32' 36' 2" x 12"




































:D FLOOR
- SEE
)N TABLE
r O.C.




FLOOR


Fig. 29.-Construction plan for center main duct arrangement of slatted floor hay drier. See Tables 10 and 11 for
dimensions.








Florida Agricultural Experiment Stations


Summary

The purpose of this bulletin is to aid the average farmer in
designing, building and selecting the equipment for a drier to
suit his needs. Those who plan to do commercial drying probably
would need a larger drier and also need to invest more money
in equipment to obtain a higher degree of efficiency.
Research data taken during 1948 and 1949 indicate how hay
or seed may be dried on the type drier described in this bulletin.
It is apparent that Florida hay crops can be grown and processed
into high quality hay.
The drying equipment needs of farmers and cattlemen are
so varied that it is not practical to include plans in this bulletin
to suit everyone's requirements. The recommendations and
drawings included in this bulletin are primarily to assist anyone
in designing a hay or seed drier which will operate satisfactorily
under Florida conditions.
The Agricultural Engineering Department of the Agricul-
tural Experiment Station and Extension Service will assist resi-
dents of the state of Florida with special problems encountered
in the design of drying equipment.


Literature Cited
1. COOPER, A. W., and E. L. MILLER. Planning and operating a mow
hay curing system. Purdue Univ. Agr. Exp. Sta. S. C. 355. 1949.
2. DAVIS, ROY B., JR. Supplemental heat in mow drying of hay. Agr.
Eng. Jour. 28: 7. 289, 290, 293. 1947.
3. DAVIS, ROY B., JR., and GORDON E. BARLOW, JR. Supplemental
heat in mow drying of hay. Part II. Agr. Eng. Jour. 29: 6: 251-254.
1948.
4. DAVIS, ROY B., JR., G. E. BARLOW, JR., and D. P. BROWN. Supple-
mental heat in mow drying of hay. Part III. Agr. Eng. Jour. 31: 5:
223-26. 1950.
5. SCHALLER, JOHN A., NOLAN MITCHELL and W. H. DICKERSON,
JR. Principles of design, installation, and operation-barn hay drier.
Agr. Eng. Pub. No. 6. Tenn. Valley Auth., Knoxville, Tenn. 1945.
6. V. P. I. AGR. ENG. DEPT. in cooperation with VA. FARM ELECTRI-
FICATION COUNCIL. Handbook on design of slatted floor barn hay
drier. VFED-3. June, 1946.








Florida Agricultural Experiment Stations


Summary

The purpose of this bulletin is to aid the average farmer in
designing, building and selecting the equipment for a drier to
suit his needs. Those who plan to do commercial drying probably
would need a larger drier and also need to invest more money
in equipment to obtain a higher degree of efficiency.
Research data taken during 1948 and 1949 indicate how hay
or seed may be dried on the type drier described in this bulletin.
It is apparent that Florida hay crops can be grown and processed
into high quality hay.
The drying equipment needs of farmers and cattlemen are
so varied that it is not practical to include plans in this bulletin
to suit everyone's requirements. The recommendations and
drawings included in this bulletin are primarily to assist anyone
in designing a hay or seed drier which will operate satisfactorily
under Florida conditions.
The Agricultural Engineering Department of the Agricul-
tural Experiment Station and Extension Service will assist resi-
dents of the state of Florida with special problems encountered
in the design of drying equipment.


Literature Cited
1. COOPER, A. W., and E. L. MILLER. Planning and operating a mow
hay curing system. Purdue Univ. Agr. Exp. Sta. S. C. 355. 1949.
2. DAVIS, ROY B., JR. Supplemental heat in mow drying of hay. Agr.
Eng. Jour. 28: 7. 289, 290, 293. 1947.
3. DAVIS, ROY B., JR., and GORDON E. BARLOW, JR. Supplemental
heat in mow drying of hay. Part II. Agr. Eng. Jour. 29: 6: 251-254.
1948.
4. DAVIS, ROY B., JR., G. E. BARLOW, JR., and D. P. BROWN. Supple-
mental heat in mow drying of hay. Part III. Agr. Eng. Jour. 31: 5:
223-26. 1950.
5. SCHALLER, JOHN A., NOLAN MITCHELL and W. H. DICKERSON,
JR. Principles of design, installation, and operation-barn hay drier.
Agr. Eng. Pub. No. 6. Tenn. Valley Auth., Knoxville, Tenn. 1945.
6. V. P. I. AGR. ENG. DEPT. in cooperation with VA. FARM ELECTRI-
FICATION COUNCIL. Handbook on design of slatted floor barn hay
drier. VFED-3. June, 1946.




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