CONTROL
AND DISPOSAL
OF COTTON-GINNIN
WASTES
U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
Public Health Service
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CONTROL AND DISPOSAL
OF
COTTON-GINNING WASTES
A Symposium
Sponsored by
National Center for Air Pollution Control
Public Health Service
U. S. Department of Health, Education, and Welfare
and
Agricultural Engineering Research Division
Agricultural Research Service
U. S. Department of Agriculture
Dallas, Texas
May 3 and 4, 1966
U. S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
Public Health Service
Bureau of Disease Prevention
and Environmental Control
Cincinnati, Ohio
1967
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The ENVIRONMENTAL HEALTH SERIES of reports was estab-
lished to report the results of scientific and engineering studies of
man's environment: The community, whether urban, suburban, or
rural, where he lives, works and plays; the air, water, and earth he
uses and re-uses; and the wastes he produces and must dispose of in
a way that preserves these natural resources. This SERIES of reports
provides for professional users a central source of information on the
intramural research activities of programs and Centers within the
Public Health Service, and on their cooperative activities with state
and local agencies, research institutions, and industrial organizations.
The general subject area of each report is indicated by the two letters
that appear in the publication number; the indicators are
AP — Air PoUution
AH — Arctic Health
EE — Environmental Engineering
FP — Food Protection
OH — Occupational Health
RH — Radiological Health
SW — Solid Wastes
WP — Water Supply and Pollution Control
Triplicate tear-out abstract cards are provided with reports in the
SERIES to facilitate information retrieval. Space is provided on the
cards for the user's accession number and additional key words.
Reports in the SERIES will be distributed to requesters, as sup-
plies permit. Requests should be directed to the program identified
on the title page or to the Publications Office, Room 4112, Federal
Office Building, 550 Main Street, Cincinnati, Ohio 45202.
Public Health Service Publication No. 999-AP-31
11
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CONTENTS
Page
Welcome Address: Richard E. Boyd 1
Opening Remarks: William E. Holy 3
The Roles of Local, State, and Federal Agencies in Controlling Air
Pollution: Gene B. Welsh 5
The Roles of the State Extension's Gin and Mechanization Special-
ists: B. G. Reeves 11
Methods Employed in Harvesting Cotton: B. G. Reeves 19
Operations and Characteristics of the Cotton Gin: Edward H. Bush 25
Methods of Collecting Seed Cotton Trash: Vernon P. Moore and
O. L. McCaskill 29
Current Gin Trash Disposal Practices: A. M. Pendleton 39
Methods of Collecting Lint Cotton Trash: V. L. Stedronsky 45
Progress Report — Air Pollution Study of Cotton Gins in Texas:
Otto Paganini 51
The Outlook for Defoliants and Pesticides: Fred C. Elliot 59
The Community Gin Company's Trash Collection and Disposal
System: Andrew O'Neal 63
Practical Considerations in the Design and Operation of the In-
Line Filter: Travis C. McLain 67
Considerations for Determining Acceptable Ambient and Source
Concentrations for Particulates from Cotton Gins: Stanley T.
Cuffe and James C. Knudson 79
Recommendations for Needed Research and Development: Ralph
C. Graber 91
Panel Discussion 93
V. L. Stedronsky ' Edward H. Bush
Andrew O'Neal Stanley T. Cuffe
Otto Paganini
Summary of Conference: G. R. Herzik, Jr 101
m
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WELCOME ADDRESS
Richard E. Boyd
Regional Health Director
U. S. Public Health Service
Dallas, Texas
I am pleased to have the opportunity to welcome each of you,
both to Dallas and to this important technical symposium on the
Control and Disposal of Cotton-Ginning Wastes. The Dallas Regional
Office of the U. S. Public Health Service, which I represent, is most
privileged to be your host.
The U. S. Department of Agriculture, cosponsors of the sym-
posium and a major contributor to your program, has asked me to add
their welcome to mine.
I understand also that the National Cotton Ginners' Association
has been kept informed of the planning for this symposium and has
indicated its wishes to cooperate toward the symposium's success.
You are gathered together, today and tomorrow, to work toward
the resolution of technical problems associated with the control of
air pollution from cotton-ginning operations. Some of you were
among those who attended a similar meeting on this same subject
held in Greenville, Mississippi, in 1955. It was the recommendation
of this first meeting that a second meeting be held on these problems,
after certain field studies had been completed. This is the second
meeting, some 11 years later.
Technological changes in cotton-harvesting and cotton-ginning
operations over the past decade, and wider use of pesticides, desic-
cants, and defoliant chemicals in cotton production suggested the need
for a second technical seminar of this type to reevaluate the problem
of air pollution.
In addition, a social change in this country further supports the
need for a second meeting. As the people of this country have in-
creasingly gained access to scientific facts about the nature and mag-
nitude of air pollution and about the capability that exists for dealing
with it more effectively, they have called for greater control efforts
by the agencies that serve them at all levels of governmnt. This in-
sistence upon better air pollution control is reflected most pointedly
in the development and passage of the Federal Clean Air Act of 1963.
Many states and local agencies have responded to this same demand
by the passage of new state laws and local ordinances governing air
pollution.
New air pollution control agencies are being established each
year. These agencies are being staffed with personnel not always
experienced or trained in the field of air pollution control.
Your symposium will serve, not only as a means of reviewing
Boyd 1
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technical problems associated with the control of air pollution from
cotton gins, but also as an orientation for these new personnel.
With a better understanding of these problems, reasonable ap-
proaches to their solution should result.
COTTON-GINNING WASTES
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OPENING REMARKS
William E. Holy
Regional Program Director
First, I would like to add my welcome to that of Dr. Boyd's;
secondly, if you will allow me a few minutes of your time, there are
a few things that need to be said before we start our formal meeting.
The symposium you are attending has been designed to serve as
a means of exchange of technical information related to the interests
of the representatives of Federal, state, and local governmental agen-
cies, universities, schools, and the cotton-ginning industry here in
attendance.
You have been provided with a handout that sets forth the
primary objectives of the symposium. These objectives can be
achieved if we concentrate our efforts toward their achievement.
The agenda includes items that may be elementary to some at-
tendees. Your patience and indulgence during these presentations
will be appreciated.
We hope by the afternoon session of the second day of the sym-
posium, sufficient background information will have been presented
to set the stage for an open and free discussion of the problems that
have been covered. Out of these discussions should come guidelines
for future approaches to these problems.
I would like to take this opportunity to acknowledge the im-
portant parts the U. S. Department of Agriculture and the Cotton
Ginners' Association have played in support of this symposium. The
U. S. Department of Agriculture is a co-sponsor of the symposium
and a major contributor to the program. The research carried out at
their cotton-ginning laboratories on control of ginning wastes repre-
sents the best available technical information on this subject. It
would have been impossible to have held the symposium without their
cooperation.
The National Cotton Ginners' Association has been kept informed
of every step taken in the planning of this symposium. Their secre-
tary has advised me of their interest in the symposium and their will-
ingness to cooperate in any way that will help accomplish its objec-
tives.
The Texas Cotton Ginners' Association participated in the plan-
ning of the symposium and are contributors to the program. Their
assistance is most appreciated. I would like to mention that the
Texas Cotton Ginners' Association has published their own "Manual
on Control of Air Pollution from Cotton Gins," for use of ginners in
their association. They have also taken a leadership role in working
toward solving gin waste disposal problems.
I would also like to express my appreciation to Mr. Pendleton,
Holy 3
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Cotton Ginning Engineer, Agriculture Extension Service, and others
in Extension field work for their valuable assistance and support of
our symposium.
My colleagues at the Federal, state, and local level of air pollution
control are most interested in the conclusions or recommendations
that will result from this symposium. We feel sure reasonable solu-
tions can be achieved for the problems that will be discussed.
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THE ROLES OF LOCAL, STATE, AND
FEDERAL AGENCIES IN CONTROLLING
AIR POLLUTION
Gene B. Welsh
Regional Program Director for Air Pollution
Region IV, Atlanta, Georgia
Air pollution is not new. Natural sources such as windblown
dust, smoke, and fly ash have been with us since the beginning of
time. Manmade air pollution probably started about the time that
man began to use fire for beneficial purposes such as cooking and
warmth. Industrial development in the United States during the
late 1800's led to many new and different types of air pollution. Most
of this new pollution was due primarily to the use of coal and other
materials to produce consumer goods and provide transportation.
Thus the air pollution problem was first recognized as being pri-
marily due to smoke, dust, and dirt.
About 1948 a new type of air pollution problem was noted in
Los Angeles. This air pollution had a different appearance from
that of the usual smoke, dust, and dirt. The Los Angeles area used
oil and gas rather than coal, and many other things were different,
and yet they had an air pollution problem. This type of air pollu-
tion caused irritation to eyes, damage to plants, and other effects
that had not been evident from the other type of air pollution.
Later it was given the name of photochemical smog because it was
produced by a photochemical reaction of the gaseous pollutants in
the atmosphere.
At about the same time and shortly thereafter, a number of
acute episodes occurred during which many people died and large
numbers became acutely ill. The most dramatic episodes were those
in Donora, Pennsylvania, in 1948, and in London, England, in 1952
and 1962. In Donora, 20 deaths occurred and approximately 5,000
people became ill. In London, in 1952, approximately 4,000 deaths
above normal occurred, and thousands became ill. Just 10 years
later, in 1962, London experienced its second episode when approx-
imately 300 deaths above normal occurred and thousands of people
became ill.
i
At present, practically all major urban areas have an air pol-
lution problem of one type or another. Some of these problems are
due primarily to automobiles, some are due primarily to industry,
and some are due to a combination of sources such as the automo-
bile, industry, and commercial and residential activities. Air pollu-
tion is not a problem that affects only the large cities; some smaller
communities also have significant air pollution problems. These are
usually due to the presence of one large industry or a group of small
activities associated with one industry. Cotton ginning is a good
Welsh
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example of one activity that can contribute to a significant air
pollution problem in small communities.
Three things are usually required for the creation of an air pol-
lution problem: (1) There must be a source of pollution; (2) there
must be a method of transportation; and (3) there must be a re-
ceptor affected by the pollution. We cannot change the weather
conditions such as wind speed and direction that provide the method
of transportation of air pollution. We cannot remove all the people,
animals, or vegetation from the area affected by the air pollution,
and we cannot purify the air after it has been polluted. This leaves
only one choice: The control or prevention of air pollution must be
undertaken at its source.
As indicated previously, industrial developments in the United
States in the late 1800's created large quantities of air pollutants
primarily as a result of using coal and other raw materials to produce
consumer goods and provide transportation. In 1881, Chicago adopted
a smoke control ordinance and started the first program to control
air pollution. Shortly thereafter, St. Louis, Cincinnati, and other
cities also established smoke abatement programs. These early efforts
established the often repeated concept that responsibility for air
pollution control rests solely with the local and state governments.
From 1930 to about 1950, dramatic improvements were made in the
control of smoke by some local programs operating strictly within
the confines of this concept. We are familiar with the past success
of Chicago, Pittsburgh, St. Louis, Cleveland, and other cities that
suffered from a pall of smoke pollution and a dirty atmosphere. This
was such an obviously dirty and undesirable nuisance that we are
amazed that the population tolerated it so long.
When the Los Angeles photochemical air pollution problem
emerged; a different type of local program was established. First,
it covered an entire county; second, it received more money, re-
sources, and authority than any program had ever had before; and
third, it established probably the most ambitious and stringent air
pollution control program in the world. Even so, the very difficult
and more complex air pollution problems that faced Los Angeles
obviously would not yield to local efforts alone, no matter how vig-
orously and relentlessly these were applied. This problem, along with
the acute episodes previously mentioned and more public concern
about the air pollution problem, led to the development and establish-
ment of state air pollution programs.
Additional problems along with still more public concern about
air pollution led to the establishment of the first identifiable Federal
air pollution program. In 1955 the Federal Government was author-
ized to aid local and state air pollution programs in the field of re-
search and technical assistance. The continued growth of the national
air pollution problem coupled with the improved documentation of
its subtle as well as obvious effects on the public health and welfare
demonstrated that local and state efforts, even when backed by Fed-
eral research and technical assistance, were not adequate to cope
COTTON-GINNING WASTES
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with the challenge posed by the air pollution problem. Recognition
of this fact was reflected in the development and passage of the Clean
Air Act of 1963 and in the subsequent amendments thereto in 1965.
This added new dimensions to the Federal role in air pollution prob-
lems. It also marked an important shift in the national policy and
recognized that a combination of efforts by the local, state, and Fed-
eral agencies was necessary to control air pollution. The Clean Air
Act of 1963 reaffirmed the position that Congress took in 1955: The
prevention and control of air pollution is primarily the responsibility
of state and local governments.
For about the last 80 to 85 years, the roles of local, state, and
Federal air pollution agencies have been and still are in a phase of
development and evolution. As new air pollution problems emerge
in the future, we can expect the respective roles to be changed and
modified. At present, local, state, and Federal agencies have fairly
definite roles in controlling air pollution.
Local agencies are primarily directed toward regulatory control
of air pollution. The role of the local agency largely depends upon
the nature and extent of the problem, the funds and personnel avail-
able to operate the program, the nature of the state laws that estab-
lish the powers and duties of the local agencies, and the activities
and policies of the state agencies. Local-agency activities may range
from a one-man smoke abatement effort up to attempts by a staff of
over 200 people to control a multitude of air pollution sources, con-
duct research, and develop new approaches. The local program bud-
gets presently range from 2 cents per capita per year up to 80 cents
per capita per year. In 1965 the median budget for local agencies
was about 15 cents per capita per year. Although the local air
pollution control agency may engage in a variety of activities, it has
three general roles: (1) Defining the nature and extent of the air
pollution problems, (2) controlling and preventing air pollution (cor-
recting the problem), and (3) operating the program.
Since state agencies have not been widely and extensively
involved in air pollution control activities, their role is primarily in
the phase of development and evolution. Wide variations in their
approaches are very evident, owing to differences in their problems
and in the laws or authority for a program. In 1965, 19 states had
established some form of regulatory activity consisting of 10 active
regulatory programs, and 8 with authority and budget but not ex-
tensive involvement in regulatory activities, and 1, the State of Cali-
fornia's, with regulatory powers for only motor vehicles. In 1961,
only five states were engaged in regulatory activities, and these were
modestly funded and their regulatory role was limited. In 1965, 34
states had air pollution programs with budgets of $5,000 or more.
Thirteen of these were created during 1965 partly because of the
stimulatory effect of the Federal grants program. For 1965 the
average per capita budget in the states having programs was less
than 2 cents per capita per year. The U.S. Constitution places the
right and responsibility with the states for the exercise of policy
Welsh
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powers to protect the public health and safety. Since most states have
delegated some of this police power to cities and counties, air pol-
lution can be controlled at the local level. This does not mean that
the state agency can remain aloof from air pollution problems and
leave them entirely to the local governments. The states still have
a basic responsibility to look after the needs of their citizens and the
needs of those cities or counties they have created or authorized.
In the air pollution field, as in others, the state agency's roles can
be placed in five general categories: (1) Leadership, (2) coordination,
(3) evaluation, (4) services, and (5) operations. Leadership is a
primary role of the state agencies. Coordination must be accom-
plished with local agencies, other state agencies, and in some cases,
agencies within another state. Evaluation may be accomplished by
monitoring air quality, studying the effects, determining the effective-
ness of the local agencies, and establishing priorities for the allocation
of financial and personnel resources. Services, which probably rep-
resent the most important role of the state agencies, may include
training, technical assistance, technical information, and specialized
laboratory analyses. In their role of operations, the state agencies
may have to assume the responsibilities for air pollution emergen-
cies, conduct some research, conduct a public information program,
and in some cases, actually do the regulatory control work because
they have the specific authority or a local agency is not present in a
particular problem area. If the state agency engages in the regula-
tory control of air pollution, then it also has the three general roles
previously outlined for local agencies.
The roles of the Federal agencies are a little more specific. The
Department of Health, Education, and Welfare, and the Public Health
Service have their roles fairly well defined by the Clean Air Act.
These roles can be summarized as: (1) Research and development:
(2) technical and financial assistance to state and local programs;
(3) abatement of air pollution in international, interstate, and under
certain conditions, intrastate areas; (4) development of air quality
criteria; and (5) establishment of standards for the control of air
pollution from new motor vehicles. The Clean Air Act also specifies
that the role of other Federal agencies should be one of cooperation
with the Department of Health, Education, and Welfare, and any
other air pollution control agency in preventing and controlling air
pollution from their respective facilities.
That the responsibility for the control of air pollution should be
at the lowest level of government capable of dealing effectively with
the problem in its entirety is a generally accepted concept. This
has been amplified by Section 101 of the Clean Air Act, which spe-
cifically states that the prevention and control of air pollution at its
source is the primary responsibility of state and local governments
and that Federal financial assistance and leadership are essential to
the development of cooperative Federal, state, regional, and local
programs to prevent and control air pollution. If we accept either
or both of these statements, then the roles of the local, state, and Fed-
eral agencies in air pollution control are fairly well defined. In
COTTON-GINNING WASTES
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simplest terms, the local agencies control air pollution. The state
agencies assist the local agencies and do the control work where
there is no local agency or when the problem is beyond the capa-
bility of the local agency. Federal agencies assist the state and local
agencies in the prevention and control of air pollution, support re-
search, and engage in activities that are beyond the resources and
capabilities of the state and local agencies.
Air pollution control cannot be accomplished without close coop-
eration among all levels of government, industry, and the general
public. The air resource of any area, whether it is a city, a county,
a state, or an entire nation, will be controlled or neglected in pro-
portion to the extent of the citizens' desire and demand. Certainly,
everyone has a role in the control of air pollution.
Welsh
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THE ROLES OF THE STATE EXTENSION'S
GIN AND MECHANIZATION SPECIALISTS
B. G. Reeves
Extension Cotton Mechanization and Ginning Specialist
Texas Agricultural Extension Service
Texas A&M University
College Station, Texas
Because techniques for accurately measuring the lint and seed
value of mechanically harvested, unginned cotton have not been
perfected, the first sale that places these products in the market chan-
nels normally occurs after ginning. This makes ginning the last step
in cotton production and points up the importance of producers' un-
derstanding the ginning process. If quality of the lint and seed is to
be preserved during ginning, then harvesting practices should be
geared to the capabilities of the local ginning facility.
The major objectives during the ginning process are to obtain
maximum dollar returns for the producer from each bale and main-
tain fiber properties for the manufacturer and ultimate consumer.
Success in achieving these aims is determined primarily by: (1) The
type of harvesting job done, or the condition of seed cotton arriving
on the gin yard; (2) the capabilities of the equipment in the gin; and
(3) the judiciousness of the selection and use of ginning equipment
by ginners as determined by the condition of the cotton and the
status of current market premiums and discounts.
Although ginning research has shown that the sequence of ma-
chinery used and the skill of the gin operator displayed in ginning
have a marked effect on bale value, the condition of the seed cotton
arriving on the gin yard has a greater effect. Growing conditions and
resulting inherent qualities of lint and seed vary from year to year,
but techniques and practices controlled by producers have much to
do with the conditions of harvested seed cotton. Thus, the type of
harvesting job done largely determines the results obtained from the
ginning process.
RECOMMENDATIONS FOR GIN MACHINERY
SEQUENCE
The local ginner is in a position to exercise good judgment in
the selection and settings of gin machinery for a given set of seed
cotton conditions. In so doing, he can make use of the machinery
recommendations established through extensive programs of the U.
S. Department of Agriculture's Ginning Research Laboratories and
of the Extension Service. These recommendations are designed to
serve the best interests of producers, ginners, and spinners. The basic
machinery components for a cotton gin processing mechanically har-
vested cotton are listed in recommended sequence:
Reeves 11
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1. Suction unloading telescope,
2. green-boll trap,
3. air line cleaner (recommended only in sandy areas to pro-
tect the machinery from abrasion),
4. bulk feed control unit,
5. dryer (24-shelf tower or equivalent) with 3-million Btu
burner with modulating or automatic moisture-sensitive
control,
6. a 6- or 7-cylinder inclined cleaner with grid selection,
7. bur machine,
8. green leaf and stick machine,
9. dryer (24-shelf tower or equivalent) with 3-million Btu
burner with modulating or automatic moisture-sensitive
control,
10. a 6- or 7-cylinder inclined cleaner with grid section,*
11. extractor feeders,
12. gin stands,f
13. tandem saw-type cleaning with complete bypass system,!
14. press.
*Six additional cylinders of second-stage cleaning are recommended on
high-capacity gin stands. This additional cleaning is to offset the loss
of cleaning efficiency in feeder and huller fronts of stands. If the gin is
equipped with less than this amount of machinery, grades on the damper,
trashier cotton will be such that full value will probably not be realized
from the lint. Machinery bypasses play an important part in a modern
gin. They allow the gin operator to fit machinery selection to the con-
dition of the cotton to be ginned. In this way the gin plant is made
flexible, excessive machining of clean or high-grade white cotton can
be avoided and trashy low-grade, light-spotted, or spotted cotton can
also be processed properly.
fResearch tests and the experience of commercial ginners have shown
that cotton should enter the gin stands with a fiber moisture content of
6.5 to 8 percent. This is a desirable goal in that fiber length can be pre-
served and other fiber qualities such as neps and short fibers can be
maintained within desirable limits when the lint and seed are separated
at this moisture level. Weather conditions in some areas are such that
fiber moisture will often be at the 4 to 5 percent level in the field. This
fact alone plays a major role in the Texas High Plains cotton produc-
tion for it makes stripper harvesting feasible. Dry burs do not cause
damage to seed cotton held in storage before ginning and can be easily
removed during ginning. This also means that dryers are not always
needed to facilitate proper seed cotton cleaning, ginning, and lint cleaning,
but that moisture should be added to the fiber in the overhead cleaning
equipment to protect the qualities of the fiber from the action of the gin
stand and lint cleaners. Moist-air-type fiber moisture restoration equip-
ment can be used for this purpose to approach the desirable goal of 6.5
to 8 percent fiber moisture in the gin stands. Moisture-air-type fiber
moisture restoration equipment is also useful to eliminate the problems
caused by static electricity during ginning of extremely dry cotton. !'
12 COTTON-GINNING WASTES
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CAPABILITIES OF THE GIN COMPONENTS
Green-Boll Trap. Since green bolls, rocks, and other, similar
types of objects should be removed from cotton before it enters the
ginning machinery, all gins should be equipped with a green-boll
trap. These units are sometimes referred to as rock traps. Rocks and
tramp iron can damage gin machinery severely, and the wet fibers
of green bolls are likely to stick to gin machinery saws and cause a
considerable reduction in the gin plant's efficiency. Sometimes shut-
down periods are required for picking the gin stand saws. At times
the sap from green bolls may cause dust and trash to build up inside
fan scrolls, and this can also cause shutdown periods for cleaning.
Boll traps for gins are available in various models. Many are
efficient at green-boll removal; however, in high-capacity gin plants,
some green bolls enter the gin machinery if a relatively high per-
centage of green bolls is present in the cotton. For this and other
reasons to be discussed, green or unopened bolls should be separated
from the mature cotton during stripper harvesting. Highly efficient
green-boll separators have been developed for use on strippers. When
green bolls are efficiently removed during harvest, the performance
of gins and the quality of the lint and seed of most stripped cotton
are greatly improved.
The relatively high percentage of moisture present in green bolls
can cause deterioration in lint and seed quality during seed cotton
storage before ginning. Unopened bolls, either green or dry, normally
contain relatively immature fiber. If this fiber is not separated from
the mature fiber either as a whole opened boll or as waste in the
lint cleaners, the micronaire of the bale can be lowered. In either
case, bale value is reduced, and producers should, therefore, make
every feasible effort to separate green or unopened bolls from the
mature cotton during the stripping process.
Bulk Feed Control. Gin plants should be equipped with a bulk
uniform-feed control unit. The unit should be located in the machin-
ery sequence in such a way as to ensure that each machine is fed
cotton at the proper uniform rate for peak efficiency. The bulk feed
control unit should not be used as an overflow bin, for this results
JLint cleaning normally pays the producer a dividend in bale value on cotton
that grades below Middling White without lint cleaning. If the cotton
grades below Middling White after one stage of lint cleaning, the second
stage of lint cleaning may further increase bale value provided the mois-
ture content of the cotton is at the percent level as it enters the press
box. Bale value is the prime factor for consideration. Lint cleaning
improves lint grade by removing trash and smoothing the sample — both
involve a reduction in bale weight. If the premium for the higher grade
obtained by cleaning is great enough to offset the resulting differences in
bale weight, then lint cleaning pays the producer. Spinning qualities
of the lint can be preserved during two stages of lint cleaning provided
the fiber moisture is within the range of 6.5 to 8 percent. For these rea-
sons, the lint-cleaning system should be maintained within the recom-
mended range.
Reeves 13
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in a recirculation of the overflow cotton through the overhead clean
and drying equipment.
Dryers and Moisture Regulation. The amount of moisture in
seed cotton during cleaning and ginning is the most important factor
affecting cotton quality. Temperatures of the dryer should be ad-
justed on the basis of the moisture in the wagon sample and in the
lint at the lint slide. Temperatures of the dryer should be regulated
so that cotton is presented to the gin saw within the 6.5 to 8 percent
lint moisture range. The amount of moisture removed from the
cotton should be increased or decreased by increasing or decreasing
the temperature in the dryers, or the time that cotton is exposed
to hot air in the dryer, or both. Wet cotton passes through the clean-
ing equipment in wads that may cause chokages and inefficient clean-
ing. When cotton is ginned, damp samples are not as clean or as
smooth, and lower grades result. If cotton is ginned while excessively
dry, the fibers are brittle. Cotton cleans easily at the 3 to 5 percent
moisture level, but the fibers are weakened or broken. This results
in increased "short fiber" content. In extreme cases excessively dry
cotton suffers a staple length reduction during ginning owing to
fiber breakage. These facts emphasize the importance of fiber mois-
ture during ginning, and the part controlled drying and moisture
restoration play in efficient ginning.
Cleaners and Extractors. Stripped cotton contains burs, bracts,
sticks, stems, dead leaves, and sometimes green leaves. Each type
of trash involves a special type of cleaning job. Cylinder-type cleaners
fluff the cotton and remove sand, fine leaf, and bract particles; bur
machines extract sticks and burs; green leaf and stick machines ex-
tract burs, sticks, stems, and green leaves. Since the bur machine
is an efficient, high-capacity, dry-bur extractor, good results are ob-
tained by using a bur machine in combination with a green-leaf and
stick machine. This allows the bur machine to remove the bulk of
bur trash and prepare the cotton for the specialized action of the
green-leaf and stick machine. The slingoff principle of the stick
machine makes it especially efficient in green-leaf and stem re-
moval. If the bulk of the bur trash has been removed when the
cotton enters the green-leaf and stick machine, the benefits of the
slingoff principle are fully used in the specialized removal of green
leaves and stems. Research has shown that the best cleaning, results
are accomplished when two-stage drying, cylinder cleaning, and
extraction are used alternately in the overhead cleaning sequence.
In other words, the machinery sequence should be such that the two
stages of drying are split with cleaning and extracting machinery.
Gin Stands. The gin stand is the heart of the gin plant and should
be maintained in top condition to perform efficiently. Saws and ribs
should be inspected frequently and necessary replacements made.
Saws should be kept sharp and replaced when the diameter has been
reduced by as much as 1/16 inch. Rib and saw clearance should be
checked and maintained according to factory recommendations to
avoid fiber damage and maintain ginning capacity.
14 COTTON-GINNING WASTES
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Lint Cleaners. Tandem lint cleaning has been proved profitable
to producers on spotted, light-spotted, or low-grade cotton. Spin-
ning quality can be maintained during lint cleaning when the fiber
moisture is maintained within the 6.5 to 8 percent range. Adjust-
ment and operation of the lint cleaner are important in preserving
quality, and factory recommendations should be followed closely.
MAINTAINING THE MERCHANDISABILITY OF COTTON
IN THE GINNING PROCESS
After ginning, both sides of bales are sampled for fiber evalua-
tion. Both sides are sampled because trade rules stipulate that bale
value be based upon the low-grade side of the bale if there is a
difference in the halves of the composite sample. To improve the
merchandisability, producers of cotton should cooperate with ginners
in grouping loads of similar-quality seed cotton for block ginning.
By ginning cotton with similar-quality moisture and trash content
in blocks of several bales, the occurrence of two-sided bales can be
minimized. Wet and dry cotton should not be placed on the same
trailer since this will likely result in two-sided bales.
Gin operators should exercise diligence in their efforts to elimi-
nate two-sided bales through proper operation of gin machinery.
Gin stand breasts should be pulled when trailers are changed to
avoid getting linters in the sample as a result of the saws' running
in a dry seed roll. When remnants are married, caution should be
exercised to see that the grade and staple of the remnants are the
same or very similar to avoid widely different two-sided bales. Good
housekeeping should be practiced by pressroom crews to ensure that
only clean cotton goes into the press box.
The gin plant should be equipped with a live overflow suction
system so that overflow cotton can be placed directly on the distrib-
utor. Overflow cotton should not be dropped in the bulk feed control
bin and recirculated through the dryers and overhead cleaning. The
drying and overhead cleaning equipment should be bypassed with
the overflow cotton; otherwise, excessive drying and cleaning results
in a two-sided bale and the producer is penalized by the reduction
in bale weight.
HANDLING GIN TRASH
Handling the trash and dirt removed from machine-stripped
cotton is a part of the ginning process that can become a nuisance if
the gin plant is not equipped with an efficient disposal system. Tre-
mendous progress has been made during recent years in the develop-
ment of gin trash-handling equipment. At present, a combination of
trash collection devices can be used to collect and handle gin trash
efficiently with a minimum of hand labor. The basic components of
a gin trash-collecting facility are:
1. High-efficiency cyclones. High-efficiency cyclones are small-
diameter, long-barrel cyclones developed by the Atomic En-
Reeves 15
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ergy Commission arid adapted to the collection of gin trash.
They give satisfactory performance on the small, lightweight
trash particles encountered in ginning operations. These units
work well on high-volume, high-velocity air systems such
as the suction unloading system, the drying cleaning system,
and trash conveying systems with high-velocity fans that are
operated against fairly high resistance pressure.
2. Lint fly catchers. On condenser exhausts the air-trash sep-
arating problem involves a small amount of fine lint fly in a
large volume of air produced by fans that operate against
very low resistance pressure. This situation is not adaptable
to centrifugal-type catchers. A screen wire cage is desirable
for this trash-collecting job. The screen cage is constructed
of 14- to 18-mesh-per-inch galvanized screen wire on a cylin-
drical frame, approximately 3 feet x 4 feet. It is used to
collect the lint fly from condenser exhausts. The lint fly builds
up in a layer on the screen and sluffs off when the mass be-
comes too heavy to be held in place by the exhausting air. If
the screen is damp, the lint fly sticks to the screen and inhibits
air exhaust, which causes backpressure on the condenser and
an eventual chokedown of the gin plant. For this reason, the
screen must be kept dry for the screen cage collector to per-
form satisfactorily. Louvers can be placed around the cages or
under a roof for efficiency. Cyclones and screen cage lint fly
catchers are available in Agriculture Handbook No. 260,
Handbook for Cotton Ginners, ARS, USDA.
3. In-line filter. The in-line air filter is a recent development
of the USDA ginning laboratory, Mesilla Park, New Mexico.
It involves a stainless steel, bolting cloth (40- to 150-mesh-
per-inch) collecting action and a pressure-differential, auto-
matically operated wiping brush mechanism. This unit has
displayed desirable performance in the laboratory and in
field trials. Additional information on this type equipment is
in ARS 42-103, September 1964, USDA Southwestern Cotton
Ginning Research Laboratory, Mesilla Park, New Mexico.
This filter is adaptable to the trash-collecting problem en-
countered on lint cleaner and press condenser exhaust fans
and was designed as a replacement for the screen cage lint
fly catcher. The design is such that protection from moisture
is achieved satisfactorily without elaborate housing or
louvering.
BUR HOPPERS
Bur hoppers are used to collect trash after it has been separated
from the air used to exhaust it from the gin plant. They play a vital
role in the mechanization of gin trash handling. These units are
normally of sufficient capacity for collecting the trash from 30 to 50
bales. When equipped with a screw conveyor to distribute the trash
over the length of the bin, they are self-loading. Bur hoppers are
16 COTTON-GINNING WASTES
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elevated bottom-dump bins that dump directly into hauling equip-
ment.
TRASH DISTRIBUTORS
Distributor trucks are used to transport the trash to farms and
distribute it at a uniform rate of 2 to 4 tons per acre. Commercial
trash-distributing equipment is also adaptable to four-wheel-type
trailers. Trash distributors are of two types, low-flight screw con-
veyors and dragchains with flail-type spreaders. Both types are
power takeoff operated and play an important part in trash handling.
This equipment is fully mechanized and spreads the trash uniformly.
PRECLEANING MACHINERY INSTALLATIONS FOR
COTTON GINS
Precleaning facilities have proved beneficial to several ginners of
the state. This type facility offers the advantages that follow.
1. It protects the gin plant.
When the facility is used to preclean ground-salvaged or
stripped cotton, the sand tramp metal and other trash that
might damage the machinery of the gin plant can be removed
in the less complicated, less expensive precleaning setup.
Maintenance costs on the gin plant can thus be held to a
minimum.
2. It increases the capacity of the gin plant.
The capacity of the gin plant is increased by minimizing the
amount of material handled per bale and improving the condi-
tion of the seed cotton when stripped or ground-salvaged
cotton is handled.
3. It evens out grade differences.
According to the experience of precleaner users, grades of
stripped cotton run even as a result of the blending effect of
the precleaning operation.
The sequence of machinery recommended for a precleaning facility:
1. Suction unloading system;
2. green-boll and rock trap; (
3. cylinder cleaner—5 to 7 cylinders, grid section;
4. bur machine or stick machine.
Precleaning and storage in baskets increases some costs but reduces
others:
Extra handling requires additional labor and equipment. The
added cost ranges from $4.80 to $6.75 per bale, but the ginning
cost is reduced significantly. Tests have shown that the cost of
precleaning and storage in baskets compares favorably with gin-
Reeves 17
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ning in the usual way. By adjusting gin capacity closely to
ginning volume and using basket storage, gin cost can be reduced
by as much as $5.00 per bale.
Summary of Open Discussion
The question was raised as to what constitutes a marginal gin in
regard to the number of bales ginned per year. Mr. Reeves cited a
study by the University of Texas in 1965 that revealed a breakeven
point of 2,108 bales per year for Texas. This survey also showed that
the average gin handles about 3,233 bales per year and has an invest-
ment of $163,000.
Another question concerned the reasons for wide variations in
yearly ginning rates (yearly bales per gin) from state to state. Citing
the fact that though Texas has more gins than any other state its
average ginning rate is 3,233 bales per gin compared with 5,300 and
6,000 bales per gin for Arizona and California respectively, Mr.
Reeves stated that ginning rates mainly depend upon whether the
region is a high- or low-yield cotton-growing area. Relatively low-
yield areas, i.e., a half bale per acre, usually have corresponding
ginning rates of 1,000 to 1,700 bales per gin. There are exceptions,
but as a general rule, this is true. The average size of farm in the
gin territory and the type of gin ownership also have a bearing on
volume of ginning.
18 COTTON-GINNING WASTES
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METHODS EMPLOYED IN HARVESTING
COTTON
B. G. Reeves
Extension Cotton Mechanization and Ginning Specialist
Texas Agricultural Extension Service
Texas A&M University
College Station, Texas
The mechanical cotton-harvesting machines of today are a credit
to the inventive and productive .genius of American industry. They
provide a means of harvesting more cotton of desirable quality in
less time and at less cost than ever before. More than 80,000 of these
machines helped harvest better than 75 percent of the 1965 U.S.
cotton crop. They are in use in every cotton-producing state in ever-
increasing numbers. Their use by producers is highly important to
cotton's future. Let us examine how they may best be used to the
advantage of the entire cotton industry.
The development of modern mechanical cotton pickers and
strippers began about 100 years ago. The early models were crude
and, in many cases, inefficient, but the machines of today are well
designed and capable of doing a good job of harvesting cotton. The
factors that determine the kind of harvesting job any machine can
do in any given situation are: (1) Field conditions at harvest time,
(2) machine condition and adjustment, and (3) skill of the machine
operator.
Since American cotton producers seek both efficiency and quality
preservation during the mechanical harvesting process, each of these
factors must be given its due considerations so that it will supplement
and balance the others.
The capabilities of any mechanical cotton harvester were estab-
lished by the features incorporated into the machine by the design
engineers. Although the performance range of each machine is rea-
sonably broad, no one machine can handle all harvesting situations
equally well. This is primarily due to differences in field conditions at
harvest time.
Many practices contribute to field conditions at harvest time,
beginning with the selection and preparation of land. For best har-
vesting results with spindle-type cotton pickers and mechanical cotton
strippers, the goal is to have a uniformly mature crop in which weeds,
insects, and diseases have been controlled. Uniform plant spacing,
stalk size, row spacing, and row profile all play an important role in
mechanical cotton harvesting. Of all the field condition factors at
harvest time, probably the most important is the moisture content of
the lint. Lint moisture during harvest affects efficiency of the
machine, the techniques employed to protect cotton quality before
ginning, and, to a large degree, the quality of the cotton in the bale.
Reeves 19
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The moisture content of lint varies with the relative humidity
of the atmosphere. In early morning, around 6 a.m., the moisture
content of lint in the field may be extremely high—possibly as much
as 17 percent at 80 to 90 percent relative humidity. By midmorning—
sometimes earlier under dry, windy conditions—the relative humid-
ity should be near 60 per cent at boll height, and the lint moisture
content should most likely be 8 percent or less. Through research
and practice, this is the moisture range that has been found satis-
factory for machine harvesting.
Normally seed cotton remains in trailers or storage for several
hours, sometimes several days, before it is ginned. The spinning qual-
ity of cotton can be preserved during storage when the moisture level
of the composite mass is 12 percent or less. A lint moisture of not
more than 8 percent and a seed moisture of not more than 10 percent
are used by producers and ginners as desirable goals in seed cotton
storage. In this moisture range, the temperature in the stored seed
cotton remains low. The transfer of moisture from the trash to the
lint is slow, and the luster and whiteness of the fiber are maintained.
Seed quality is also preserved in terms of germination and vigor. This
condition is usually attained when harvesting is done in a relative
humidity of 60 percent or less from mature fields.
The moisture content of green leaves, stems, and bolls is ex-
tremely high—possibly 60 to 75 percent by weight. For this reason,
every practical effort should be employed to minimize the accumula-
tion of these materials in the harvested cotton. To reduce the amount
of green leaves and stems on the stalk, a chemical defoliant may be
applied to cotton fields where harvesting is to be done with a spindle
picker. This application is made when 60 per cent or more of the
bolls are open. When stripper harvesting is to be done before frost,
a chemical desiccant is applied to the field when 75 percent or more
of the bolls are open.
GUIDELINES FOR MECHANICAL STRIPPERS
Mechanical strippers generally operate most efficiently in cotton
that is less than 3 feet tall. Since mechanical stripping is a once over
operation, early maturing bolls must remain on the stalk until the
late-maturing bolls are open. Storm-resistant varieties should, there-
fore, be planted, for the bulk of the crop is left in the field longer
when harvesting is done by this method. Owing to the principle of
operation of the stripper, green-leaf staining of the lint can occur
when only 5 percent of the plant leaf cover is green during stripping.
Best grades are obtained with the stripper when the only trash
present is dry leaves, burs, and stems. Stripping cotton a week or
10 days after an efficient application of a chemical desiccant or after
the occurrence of killing frost when the relative humidity is 60 per-
cent or less at boll height generally gives desirable results in terms
of grade.
20 COTTON-GINNING WASTES
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The mechanical stripping method of harvesting is a dry-weather
practice, primarily because of the necessity for desiccation and good
weather in order that dry leaves be taken to the gin in brittle condi-
tion. This has been true in many observations in whatever state and
with whatever machine stripping is practiced. Before entering the
field with the stripper, dead leaves and leaves and stems should be
checked; they should be crisp and brittle for satisfactory harvesting
results.
Although the adjustments are reasonably simple on the stripper,
they are very important. The owner should be sure that his operator
understands how to make these adjustments: (1) Tension on strip-
ping mechanism, (2) elevation of stripping mechanism, (3) adjust-
ment of plant lifters or guides, and (4) travel speed.
In addition, since it is important to leave as much foreign matter
in the field as possible, the green-boll separators should be kept in
perfect operating condition, properly adjusted, and cleaned. Every
device on the stripper, such'as grid bars and screens, that takes out
dry leaf should be kept clean and maintained in top working condi-
tion. Good operation of the stripper also requires careful driving in
the row at speeds to fit field conditions. This minimizes bark and
excessive foreign matter in the sample. Reasonable care taken to
prevent mixing of different-quality cottons in the trailer, to avoid
excessive tramping on the trailer, and to bring about proper handling
between harvesting and ginning helps good seed cotton become good
lint cotton.
GUIDELINES FOR SPINDLE PICKING
The spindle picker can generally handle cotton over 3 feet tall
more efficiently than the mechanical stripper can. Provided insects
have been controlled efficiently, this type picker can normally be
expected to carry a yield in excess of a bale per acre. The spindle
picker is best adapted to the harvesting of river bottom or irrigated
cotton in areas with a sufficiently long growing season to allow full
maturity of the crop before frost occurs. Since the lint must be
exposed from the burs for the machine spindles to remove it, open-
boll varieties are best adapted to spindle picking. The spindle picker
cannot separate a large volume of dry trash from cotton as it is
harvested, and the presence of excessive amounts of green leaves
reduces the efficiency of the picking operation. Green trash also
results in the development of green-leaf stain on the lint. Grades can
be lowered in either case, owing to the addition of trash and leaf
stain. Efficient defoliation is, therefore, vitally important if desirable
grades are to be obtained in spindle picking.
If the mechanical picking method of harvesting is used, the owner
should be particularly sensitive to the importance of the following:
(1) Drum evaluation, (2) drum tilt, (3) relationship of spindle to
doffer and spindle to a moistening pad, (4) adjustment of pressure
Reeves 21
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plates, (5) proper speeds,1 (6) moisture adjustments, and (7) opera-
tion techniques—driving on row, entering field at full throttle. There
are others, but these affect the quality of every pound and the effi-
ciency of every horsepower.
SUPERVISION OF OPERATOR
Many owners may have been careful to provide all safeguards to
good stripper and picker operation down to this point and failed to
evaluate the operator or his job through strong supervision. Every
owner ought to write the County Agent or National Cotton Council
and obtain a copy of the Owner's Outline for Checking Pickers' Per-
formance and Field Method of Determining Cotton-Harvesting Losses.
There are solid, proved methods of evaluating field losses in terms of
pounds, quality, and time. This evaluation is only one step ahead of
the bank account evaluation that shows up later.
GUIDELINES FOR BETTER HARVESTING RESULTS
Selection of the harvest method is not a simple choice. Two good
yardsticks for evaluating either method are harvesting efficiency and
fiber quality. Once a choice has been made, care should be given to
selection of the best practices that make the choice a good one and
the results economically sound. A few important practices pay good
dividends in improved efficiency in either harvesting method.
1. Field layouts—short rows make all mechanical operations in-
efficient and should be avoided whenever possible.
2. Good turning rows—should be IVz to 2 times the machine's
length and should be firm, smooth, and level.
3. Uniform row profile—the drill should be slightly higher than
the middle and as uniform as possible. Beds should be prepared to fit
the mechanization plan; however, row profile is important to efficient
harvesting with either machine. Equipment used and type beds pre-
pared vary with local weather and soil conditions. Recommendations
of the State Extension Service and the Experiment Station should be
followed.
4. Three to four plants per foot of row—this plant population
results in better stalk confirmation and means more efficient harvest-
ing for the producer. A thick, uniform stand helps the ginner because
a cleaner load of cotton is generally harvested from fields with the
recommended plant population.
5. The amount of trash and moisture in cotton is largely de-
pendent upon the condition of the field when the machine enters it.
The key question is this: Is the field condition right for the practices
used?
22 COTTON-GINNING WASTES
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6. Does the machine operator know how to adjust the machine
properly? Does he care? The differences means a good or bad situa-
tion at the gin, good or bad quality for the mill, and more or less
profit for the producer. It pays the owner to see that the operator
does know and does care.
1. Is the machine itself properly prepared before harvest season?
This is necessary both for efficiency of operation and preservation of
quality. Adjustment of the machine and proper operation on an
hour-by-hour, field-by-field basis are of equal importance. A fine
stripper or a fine cotton picker requires accurate adjustment and
intelligent handling in the field. These simple suggestions along with
the careful personal use of the machine operator's manual pay good
dividends through better mechanical harvesting.
Cooperation and exchange of information between the producer
and the ginner ensure:
1. The ginning of excessively damp cotton as quickly as possible
and storage of the dryer cotton if necessary.
2. a knowledge of moisture in the cotton waiting at the gin
through measurement of moisture with electronic moisture meters,
3. proper handling of both lint and seed,
4. and, finally, a more profitable product for both the producer
and the spinner.
The future of American cotton depends upon how well the in-
dustry promotes its use, protects its quality, and competes in price.
Today there is a need for reduced costs, but cotton quality is not
being sacrificed as a part of cost cutting. Mechanical harvesting offers
important cost-cutting possibilities that will benefit every segment of
the cotton industry from producer to consumer. It will play an in-
creasingly important role in the future of U.S. cotton.
Summary of Open Discussion
In regard to the prospects for development of field extraction
equipment, it was revealed that attempts at this development have
been made during the past 20 to 25 years and that currently four
or five companies are working on the problem. This research has two
major obstacles to overcome in developing a marketable device:
(1) Control over cotton moisture and (2) high initial investment by
the cotton ginner.
Reeves 23
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OPERATIONS AND CHARACTERISTICS
OF THE COTTON GIN
Edward H. Bush
Executive Vice President
Texas Cotton Ginners' Association
Gentlemen, it is my pleasure to speak this morning on the broad
subject of operations and characteristics of the cotton gin. Perhaps a
more suitable title would be "What a Cotton Ginner Does and How
He Goes About It." In discussing the program that will be presented
to you in the next 2 days, we felt that this presentation should vary
somewhat from the technical and attempt to give you the background
of the people in the ginning industry and their operations.
Twenty years ago, cotton gins were the hub of the cotton-farming
community. They still are today, though this is about the only resem-
blance that remains. Twenty years ago, cotton gins of the most
modern type cost approximately $75,000 to $80,000. This was for
land, buildings, equipment, offices—in fact, the total investment.
Today the total investment approaches in many instances $400,000.
The $80,000 plant I spoke of required probably something less than
1,000 bales' volume per year in order to break even before beginning
to show a profit. Today our figures indicate that the modern plant
requires 3,500 to 3,600 bales' volume before any profit can be realized.
The earlier plants ginned at a rate of about 3 to perhaps a maximum
of 4 bales per hour. Plants today often exceed 15 bales per hour.
In terms of trash and dirt, plants over 20 years ago were handling rela-
tively clean handpicked or handsnapped cotton containing perhaps a
maximum of 400 pounds of all types of waste material per bale.
At 4 bales per hour, this would be 1,600 pounds of waste per hour.
Contrast that with today's plant ginning at 15 bales per hour—han-
dling trash at a maximum rate of about 1,500 pounds per bale—you
can readily see that the volume of waste material has jumped to
22,500 pounds per hour.
Now what has brought all this about? Perhaps the simplest ex-
planation is mechanization. Because of the need to cut costs and
eliminate harvest labor, which was not only difficult to obtain but
also expensive to manage and use, the cotton farmer has been forced
to mechanize to the maximum. This mechanization with cotton
pickers and cotton strippers has brought tremendous tonnages of
trash to the gin, which must be removed and disposed.
Now, just what does a cotton gin do? Primarily its job is to take
raw seed cotton and separate the seed and the lint. But it does other
things. It packages the lint into approximately 500-pound bales and
it provides for disposal of the seed either to an oil mill for crushing
or back to the farmer if he wants to save them for planting purposes.
Cotton gins have always done some cleaning, but the need for remov-
ing trash has accelerated so rapidly over the past few years that this
Bush 25
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is a prime function of the gin today and has resulted in the addition
of many and varied types of specialized cleaning equipment.
If this were all that a cotton ginner does, my talk could end
here; but as I pointed out, the cotton gin is the hub of the cotton-
farming community around him. It is a service organization dedicated
to helping the cotton farmer in any way it can to be more productive
and do a better job with reduced costs. As a result, the demand for
ginners' services has broadened drastically. Many ginners now help
farmers obtain good planting seed, fertilizers, insecticides, weed
control chemicals, defoliants and desiccants, airplanes and ground
equipment for applying these various chemicals, harvest labor, and
even trailers and other necessary transportation for moving the crop
from the field to the gin. Perhaps the greatest impact on this industry
since the rapid development of full mechanization has been the
speed with which the crop must now be processed. Twenty years
ago the harvest season probably lasted 4% to 5 months in most areas
and sometimes longer. Today the peak season is approximately 2
months. This then has meant that ginners are more conscious than
ever before of having a tremendous investment to be used only a
very small portion of the year and of having had it sit idle the rest
of the time. Consequently, ginners think in terms of 24-hour opera-
tions during the peak season. They are forced by economics to operate
uninterruptedly if possible throughout this period. They know that,
if for some reason they must shut down during their peak season,
their customers will go elsewhere for service. A lost customer means
lost volume, and in many instances, instead of reduced profit, a loss.
Just one customer may sometimes make the difference. Ginners as a
consequence are extremely sensitive to any interruption in their
operations.
They are usually community leaders. They are anxious to be
good citizens and provide the utmost in service to their customers
and their communities. This is traditional in the ginning industry.
For this reason it is extremely important to understand that
ginners are equally as concerned with trash and waste disposal as
the general public is. The problem here lies then not with an appre-
ciation of the problem nor with a desire to correct it but with the
know-how and economic resources that can be brought to bear to
solve the problem. The added investments that have been necessary
and the shortening of the season have narrowed ginners' margins of
profit to such an extent that in the last 3 years nearly all gins have
merely managed to exist. To complicate the situation further and
to look to the future, we now have a cotton program known as the
Food and Agriculture Act of 1965 that will reduce acreage and cotton
planted approximately 30 percent this year and for the next 3 years
following. This obviously means for more ginners an across-the-
board cut of one-third of their volume. This confronts them now
when they are already operating at or near the break-even point.
Most ginners view this as a fight for survival. They see no oppor-
tunity for profit and thus they are reluctant to consider any expendi-
26 COTTON-GINNING WASTES
-------
ture that is not of the direst need. Add to this the fact that, even
though for the past 15 years our Association, together with the United
States Department of Agriculture's Cotton Ginning Laboratories, and
private industry, have been trying to develop cheap, acceptable ways
of collecting and disposing of gin wastes, we are still in need of
improved techniques, equipment, and methods in this area. Vast
strides have, however, been made. Rather than discuss these in detail
as they will be discussed by others during the next 2 days, I will
merely say that it is now possible in most instances, I think, for a gin
to control dust and waste emissions adequately within limits accept-
able to its surrounding neighbors and community. We have many
individual cases in our largest cities and in our smallest ginning
communities that prove this point. These gins have met this problem,
have availed themselves of the existing technology, and have applied
these techniques to the mutual benefit of their own business as well
as their neighbors. None of these gins have the same emission con-
trol problems nor the same system of control.
The technology is here. The main problem now and for the for-
seeable future is economic. Newer, cheaper, and more efficient collec-
tion, disposal, and control systems must be devised. If this is done,
I know that most ginners will rapidly adopt the new equipment and
procedures.
Like most other businesses we have experienced an increase in
our average income during the past 10 years. The average income for
the gin averaging 6,000 bales increased by 23 percent in that period.
Nevertheless, our cost of processing these 6,000 bales jumped 36.6
percent in that same period. This does not include a sharp increase
in the amount of investment in machinery. Our labor costs increased
from 87 cents per hour in 1955 to over $1.25 an hour in 1965. The
actual horsepower necessary for the ginning process increased from
352 to 404 with a resulting increase in kilowatt-hour costs to gin
cotton.
All good gin management sets aside a certain amount of profits
for improvement of equipment and addition of new systems. But the
amount of profits to be set aside decreases as operational costs rise
and the income decreases.
I must reemphasize that new equipment will be added and new
procedures adopted if they are economically sound and the equipment
is priced within reach of the ginners'(budget.
I shall be happy to discuss in detail any of the operating pro-
cedure, equipment, and problems that ginners face if you will but ask.
Summary of Open Discussion
Mr. Bush emphasized that the title "ginner" may be applied to
the owner of the gin or to the gin supervisor or foreman and that
the distinction between the two should be maintained.
Bush 27
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In response to an inquiry on gin ownership, Mr. Bush gave the
following breakdown:
30% are cooperatively owned,
53% are independently owned (including corporations),
17% have multiple ownership (more than 5 to the owner—usu-
ally oil mills).
28 COTTON-GINNING WASTES
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METHODS OF COLLECTING
SEED COTTON TRASH
Vernon P. Moore
Officer in Charge
Oliver L. McCaskill
Research Agricultural Engineer
U.S. Cotton-Ginning Research Laboratory
Stoneville, Mississippi
Agricultural Engineering Research Division
Agricultural Research Service
U.S. Department of Agriculture
For purposes of this discussion we shall loosely define seed
cotton trash as the material that is removed from the gin building by
the high-pressure fans. The material is primarily from the seed
cotton cleaners. There are dust and dirt, of course, which must be
dealt with, but for the most part, the gin's seed cotton-cleaning
equipment removes relatively heavy plant parts consisting principally
of leaf, burs, sticks, and stems. The lighter materials or trash con-
taining a preponderance of fibrous materials handled by the high-
pressure fans are from the gin's moting system and lint cleaners.
Machine harvesting was begun in earnest after World War II,
and last year, 77 percent of the crop was harvested by machine—58
percent with pickers and 19 percent with strippers. Of the re-
maining 23 percent of the crop, 16 percent is handpicked, 6 percent
handsnapped, and 1 percent machine scrapped. For all practical
purposes, clean handpicking no longer'exists. Most of the handpicked
cotton contains as much foreign matter or more than machine-picked
cotton does and is rapidly decreasing in volume so that it warrants
no special consideration. Handsnapped cotton, in terms of trash, can
roughly be put into the same category with machine-stripped cotton.
Therefore, if, the gin's trash system can handle machine-picked or
machine-stripped cotton, depending upon in what area of the Cotton
Belt the plant is located, it can cope with almost any cotton brought
to it, the exception, if any, being the 1 percent machine-scrapped
material.
Machine-picked cotton usually contains about 80 pounds of for-
eign matter per bale consisting of 29 pounds of hulls, 43 pounds of
leaf trash and dirt, and 9 pounds of sticks and stems (Table 1). An
average bale of machine-stripped cotton contains 525 pounds of for-
eign matter consisting of 397 pounds of hulls, 50 pounds of sticks
and stems, and 78 pounds of leaf trash and dirt.
At a ginning rate of 15 bales per hour, the quantity of foreign
matter that must be handled is impressive, amounting to over 1,200
pounds for machine-picked cotton, 7,700 pounds for machine-stripped
cotton, and 13,000 pounds for machine-scrapped cotton. Machine
Moore and MeCaslull 29
-------
scrapping is a relatively new practice but is becoming rather wide-
spread. An analysis of the foreign matter content of machine-
scrapped cotton in the Mississippi Valley shows that it contains 329
pounds of hulls, 143 pounds of sticks and stems, and 398 pounds of
leaf and dirt, making a total of 870 pounds of foreign matter per bale
to be dealt with.
TABLE 1 — AVERAGE AMOUNT AND TYPE OF TRASH IN
SEED COTTON HARVESTED BY VARIOUS METHODS, Ib/bale
Types
Hulls
Sticks and stems
Leaf and dirt
Total
Machine
picked
29
9
43
81
Machine
stripped
397
50
78
525
Machine
scrapped
329
143
398
870
This mass of material must be collected from a total of over
43,000 cubic feet of air per minute (Table 2). The fans removing the
trash from the lint cleaners also airwash the grid bars to keep them
clean. The material removed from the lint cleaners consists primarily
of fine-leaf trash and short fiber.
TABLE 2 — SIZE OF FAN AND AIR VOLUME REQUIRED FOR
VARIOUS SEED COTTON TRASH-HANDLING SYSTEMS
(BASED UPON 12 TO 15 bales/hr)
.., Fan sizes Volume,
Systems Push Pull rfm
2 No 50
Trailer-unloading system IN SERIES 8,500
No. 1 drying and
cleaning system
No. 2 drying and
cleaning system
Live overflow
Trash fan
Lint cleaner trash fan
No. 45 No. 50
No. 45 No. 50
No. 35
No. 30
2 No. 40
9,000
9,000
4,000
3,000
10,000
Total 43,500
30 COTTON-GINNING WASTES
-------
The emissions from the trailer-unloading system consist prima-
rily of dust, fine-leaf trash, and some fibers (Figure 1). The exhausts
from the drying and cleaning systems pick up leaf trash and dust
from the cylinder cleaners, and burs, sticks, and stems from the stick
and green-leaf machines (Figure 2). The exhaust from the live over-
flow contains a small quantity of lint fly and dust. This system is
similar to the trailer-unloading system. The function of the so-called
trash fan is to remove the trash from the feeders and gin stands
(Figure 3). This material consists of every type of foreign matter
in cotton, including burs, sticks, and leaf trash from the feeders; burs
and sticks from the gin stand huller fronts; and fibrous material, leaf
particles, immature seeds, and grass from the gin stand's moting
system.
SEPARATOR
VACUUM DROPPER
- SUCTION
TELESCOPE
COTTON
TRAILER
TO
CYCLONE
EED CONTROL
Figure 1 — Typical seed cotton-unloading system.
AUTOMATIC N
FEED CONTROL \
CYLINDER CLEANER
FAN
CYCLONES
FAN
Figure 2 — Typical seed cotton drier-cleaner installation.
Moore and McCaskill
31
-------
LINT
CLEANER
TO
CYCLONE
TRASH FAN
TRASH FAN
Figure 3 — Typical gin stand feeder's and lint cleaner's trash-handling system.
There are no up-to-date data on the volume of material emitted
by the various systems or on the analysis of material by particle size.
With expected new personnel it is anticipated that some of this work
will be done next season.
The small-diameter cyclone has virtually eliminated the old con-
ventional large-diameter cyclone for gin use. It has proved less
expensive, easier to install, and more efficient. One marked dis-
advantage of the smaller unit, however, is that its tolerance in sizing
is much less than that of the large-diameter cyclone.
For proper operation of the system, the cyclone must be sized
correctly. If the cyclone is too small for the air volume, the static
pressure on the system is too great for proper operation. In extreme
cases an excess of foreign matter blows out of the top and bottom
of the cyclone. If the cyclone is too large for the amount of air, then
the centrifugal force created is not sufficient to provide effective sepa-
ration between air and foreign matter. Thus an excessive amount of
foreign matter is carried out of the cyclone with the air. When
properly sized, a small-diameter cyclone has a working static pressure
of about 5 inches of water.
The measurement of air volumes is a subject unto itself and will
not be discussed here, but a working knowledge of air measurement
is basic to the design of pneumatic materials-handling and collection
systems for cotton gins. A simplified explanation is given in the
Handbook for Cotton Ginners, Agricultural Handbook No. 260.
When new gins are constructed or new trash-handling systems
installed, the fan and piping should be installed and air measurements
should be taken to determine the proper size of the cyclone. The
32
COTTON-GINNING WASTES
-------
stack velocity of cyclones should not exceed 500 to 600 feet per min-
ute (fpm). Within limits, the smaller the cyclone for a given amount
of air, the more efficient the separation of air from trash. This is why
the small-diameter cyclone is rapidly replacing the old conventional
type (Figure 4). In fact, the old-type cyclone was never meant for
handling the type of material emitted from cotton gins. For most
cotton gin trash, the barrel of the cyclone should have straight sides
or should be tapered from top to bottom rather than from bottom to
top. This type cyclone is no longer recommended for use in gins
except possibly for the collection of cottonseed.
AIR,
cfm
3,000
6,000
12,000
CYCLONE DIMENSIONS, in.
A
16
22
30
B
32
44
60
C
64
88
120
D
56
77
105
E
8
11
15
F
%
1
IVs
G
4
SVz
7V2
H
36
49%
67V2
1
40
55
75
J
4
6
6
Figure 4 — Dimensions of a large-diameter cyclone.
The small-diameter cyclone that came into widespread use sev-
eral years ago has proved effective (Figure 5). It creates more static
pressure than the old conventional unit does but its higher efficiency
makes up for this increased cost of operation. For best efficiency, an
effort should be made to keep cyclones to a maximum of 34 inches
in diameter. For example, one 18-gauge, 34-inch cyclone handles
3,000 cubic feet of air per minute; two 34-inch cyclones handle 6,000
cubic feet of air per minute. Four of them are needed to handle
12,000 cubic feet per minute (cfm). If for some reason cyclones
larger than 34 inches are required, they should be made from 16-
gauge metal as opposed to 18-gauge metal for sizes up to 34 inches
in diameter. Standard practice for splitting the air into two or four
cyclones requires rectangular transitions that are one-half the diam-
eter of the cyclone in height and one-fourth the diameter in width
(Figure 6). These clusters have proved satisfactory.
It is standard practice to place all but one of the cyclones in a
battery beside the gin building (Figure 7). They all discharge into
a screw conveyor that has a dust-tight cover. The conveyor in turn
discharges trash through a conventional dropper into an air line that
Moore and McCaskill
33
-------
conveys it to a bur house or incinerator. The air from one of the gin's
fans, preferably the fan handling the lint cleaner's trash, is used for
this purpose, because this fibrous material has a tendency to choke
a conveyor (Figure 8). This is especially true if this material must
be conveyed past a bearing hanger.
CYCLONE DIMENSIONS, in.
AIR
ENTERING
CYCLONE,
cfm
3,000
6,000
12,000
SINGLE
DOUBLE QUADRUPLE
DIA — DC DIA — Do DIA — DC
34.0
24.0
48.0
34.0
68.0
48.0
17.0
24.0
34.0
CYCLONE DESIGN PROPORTIONS
D = °
0 2
= 2D
S0 = °0 8
Z0 = 2DC
J = 12 in. (MINIMUM)
c
Figure 5 — Dimensions of a small-diameter cyclone.
Figure 6 — Inlet transition proportions for multiple small-diameter-cyclone mounting.
34
COTTON-GINNING WASTES
-------
TRASH INLET
| CONVEYOR
TRASH FAN DROPPER -»43£
IN GIN UKUr-r-E.K-*7^;
//*"~\ v*"-^ y
d
Figure 7 — Trash collection system for a battery of cyclones.
TRASH FROM _
COLLECTING SYSTEM
INCINERATOR
OR
LARGE TRASH HOUSE
Figure 8 — Collecting trash from a battery of cyclones for disposal.
Moore and McCaskill
35
-------
This system offers several advantages. An incinerator must be
100 feet from any building. By placing the battery of cyclones beside
the gin and collecting all the trash into a single line, several hundred
feet of pipe are saved as well as the power cost to move the large
volume of air the greater distance. Moreover, this system requires
one less cyclone and fan since the trash fan picking up under the
battery of cyclones, and the cyclone over the incinerator are perform-
ing a double function by carrying trash from one point in the gin
and by handling the remaining material from the battery of cyclones.
In some areas the dust coming from the exhaust of the cyclones
may be objectionable. In this event further filtering is necessary.
This can be done several ways. Probably the best would be to use an
in-line filter or a commercial unit employing somewhat the same
principle (Figure 9). Because the in-line filter will be described in
a companion paper (McLain), no details will be given here. Com-
mercial units come in two general types, those that use a fine-mesh
screen as a permanent filter and those that have a roll of disposable
filter media. Both of these types use a differential-pressure switch
to activate the cleaning or roll-turning mechanism. These filters
handle a relatively large volume of air for a given size at less than
% inch of water static-pressure demand (Table 3). For example, all
the high-pressure air from a 12- to 15-bale-per-hour gin could be
filtered through a 7- x 15- or 10 x 10-foot filter unit costing about
$6,000. An installation for the rain-grown area would probably be
somewhat as shown in Figure 10. The filter media would have to be
kept dry.
TABLE 3 — FILTER SIZE REQUIREMENTS FOR HANDLING
VARIOUS AIR VOLUMES (BASED UPON 600 fpm
DISCHARGE VELOCITY)
Width, ft
5
10
15
20
4
Capacity,
cfm
7,600
15,300
22,900
28,900
Height, ft
7
Capacity,
cfm
15,300
30,600
45,900
57,800
10
Capacity,
cfm
22,900
45,900
68,800
86,700
When the trash from the battery of cyclones is picked up by the
lint cleaner's trash fan and carried to a cyclone on the bur.house, a
second automatic air filter may be used to clean the discharge air
from the cyclone if desirable (Figure 11). An air volume of 4,000
36 COTTON-GINNING WASTES
-------
cfm being assumed, a 39-inch cyclone and a 4- x 5-foot filter would
be required. A cyclone filter installation such as this would cost an
estimated $2,000 for the 4- x 5-foot filter and $575 for the cyclone.
The vacuum dropper under the cyclone and filter could be driven by
the same motor that drives the distributor conveyor in the house.
CONTAMINATED AIR
V.
PLENUM
CHAMBER
FOREIGN MATTER
SWEEPER BRUSHES
CARRIER CHAIN
CLEAN
AIR
ARRESTOR MEDIA
EXPANDED METAL
REINFORCEMENT
Figure 9 — One type of filter for removing foreign matter from cyclone exhaust.
TRASH LINES
FROM GIN
TRASH
CYCLONES
COLLECTING
CONVEYOR
AIR FROM
GIN
PLENUM
CHAMBER
VACUUM
DROPPER
TO TRASH
HOUSE OR
INCINERATOR
SELF-CLEANING
SCREEN-TYPE
AIR FILTER
LOUVERS
CLEAN
AIR
CLEANOUT DOOR '
Figure 10 — Typical installation of filter for cleaning air from a battery of cyclones.
Moore and McCaskill
37
-------
It has been found that, by using a cyclone filter unit such as just
described along with an airwash or second filtering, the air is cleaned
sufficiently to be returned to the gin building. This was demonstrated
on a pilot model basis at Mesilla Park last season and in limited trials
with lint cleaner trash in connection with a packaging research
project at Stoneville.
CYCLONE
FROM TRASH
CYCLONES
AUTOMATIC AIR FILTER
DRIVE MOTOR
OPEN CONVEYOR
-ALARM SWITCH
TO INDICATE
FULL HOUSE
TRASH HOUSE
Figure 11 — Cyclone filter installation for trash or bur house.
The gin can be cleaned by using equipment and techniques now
available. The question of simple economics remains. It is doubtful
that half the gins in the United States can afford $20,000 to $30,000
for an elaborate trash collection system that would operate only 6
weeks out of the year.
REFERENCES
Charges for Ginning Cotton, Costs of Selected Services Incident to
Marketing, and Related Information, Season 1964-65. Economics Re-
search Service, Marketing Economics Division; and Consumer and
Marketing Service, Cotton Division, U.S. Department of Agriculture.
What We Know About Air Pollution Control. Special Bulletin No. 1,
Texas Cotton Ginners' Association (March) 1965.
Control of Cotton Gin Wastes. Texas State Department of Health,
.Division of Occupational Health, Austin, Texas (Jan.) 1957.
Harrell, E. "A., and Moore, V. P., Trash-Collecting Systems at Cotton
Gins, ARS 42-62 (Jan.) 1962.
Handbook for Cotton Ginners. Agricultural Handbook No. 260 (Feb.)
1964.
38
COTTON-GINNING WASTES
-------
CURRENT GIN TRASH DISPOSAL PRACTICES
A. M. Pendleton
Cotton-Ginning Engineer
Federal Extension Service
U. S. Department of Agriculture
Five harvesting methods, two manual and three mechanical, are
used to gather the U. S. cotton crop. Table 4 shows the percent of
cotton harvested by each method for the U. S. and for a few selected
states. With 58 percent gathered by spindle pickers and 19 percent
by mechanical strippers in 1964, hand harvesting of cotton is obvi-
ously a fast-disappearing practice.
Table 5 shows that the total pounds of weight of the seed cotton
mass required to make a 500-pound bale of cotton varied in 1964
from 1,383 pounds to 2,473 pounds. Since most of the U. S. crop is
now harvested by the spindle picker or stripper, U. S. gins obviously
must be geared to handle the volume of trash gathered by these two
predominant harvesting methods. Table 6 shows that machine-picked
cotton in 1964 carried about 89 pounds more trash and moisture than
handpicked cotton did. It also shows that the average machine-
stripped bale carried an estimated 1,090 pounds more trash than the
handpicked bale did. This means then that a gin with a volume of
3,000 bales of machine-picked cotton in 1964 handled 267,000 pounds
more trash and moisture than it would have if it had ginned all hand-
picked cotton. The total load of trash and moisture removed from
seed cotton probably amounted to about 366,000 pounds. Since the
ginning season grows ever shorter with mechanized harvesting, about
80 percent of this disposal problem takes place each year during a
6-week period.
TABLE 4 —METHODS OF HARVESTING COTTON, CROP
OF 1964"
Method, %
Handpicked
Handsnapped
Machine picked
Machine stripped
Machine scrapped
U. S. A.
16
6
58
19
1
Ark.
20
5
93
2
—
Calif.
3
_ —
94
—
3
Miss. S. C.
31 37
1 —
68 63
— —
— —
Tex.
2
13
20
64
1
100% 100% 100% 100% 100% 100%
"Source: U. S. Department of Agriculture.
Pendleton 39
-------
TABLE 5—WEIGHT OF SEED COTTON/500-lb bale.
AVERAGE U. S. BALE, CROP OF 1964a
Method, Ib
Handpicked
Handsnapped
Machine picked
Machine stripped
Machine scrapped
1,383
2,049
1,472
2,159
2,473
"Source: U. S. Department of Agriculture.
TABLE 6 — APPROXIMATE EXCESS OF TRASH AND
MOISTURE/500-lb bale ABOVE THAT CONTAINED IN
HANDPICKED COTTON, CROP OF 1964
Method, Ib
Handsnapped 666
Machine picked 89
Machine stripped 776
Machine scrapped 1,090
The trash problem, is much more difficult where machine strip-
ping is practiced—particularly in Texas and Oklahoma. A plant that
ginned 3,000 bales of machine-stripped cotton in 1964 handled 2,328,-
000 pounds more trash and moisture than a handpicked gin did with
a total volume of probably 2,500,000 pounds. Again, about 80 percent
of this volume was handled in a 6-week to 2-month period. This
brief picture indicates that the size of the gin trash-handling problem
at an average cotton gin depends upon the harvesting practice em-
ployed. It also points out that the problem changes instantly with a
change in harvesting practice.
Three principal pieces of equipment are commonly used in
cotton gins to collect the trash: (1) The cyclone, including both the
very efficient small-diameter type and the larger commercial type;
(2) the lint fly catcher or screen cage; and (3) the in-line filter. Mr.
Moore; Mr. McCaskill, and Mr. Stedronsky of the U. S. Cotton-Ginning
Laboratories discuss the operation of these in detail. I shall point out
only that these are used in groups to form the more elaborate systems
capable of trapping the large amounts of air currently used in cotton
gins.
40 COTTON-GINNING WASTES
-------
To prepare for this conference, I consulted with engineers of two
leading manufacturers of cotton gins to determine the range of air
volumes used in a current-model cotton gin where air is fully used
for lifting and propelling materials as well as for aiding in drying,
cleaning, extracting, lint cleaning, separating, and actual ginning.
The range of air volume employed for an 8-bale-per-hour gin was
calculated at 50,000 to 75,000 cfm. The range for a 12-bale-per-hour
gin was from 65,000 to 80,000 cfm. This means that, with the use of
the three methods of trapping air previously mentioned, installations
are engineered to capture this large amount of air if they are attempt-
ing to do the total job. This will be discussed later. For doing this
job well, a complicated and costly set of installations is required.
In calculating the cost of incinerating burs with a complete col-
lection system, as we understand it today, I have worked with a
prominent supplier of trash-handling equipment to estimate the cost
of complete dust control and incineration equipment for a 12-bale-
per-hour cotton gin handling stripped cotton. The estimate amounts
to $29,049.50 for installation of a complete cyclone system, an in-line
filter trap system, and a commercial incinerating system, including
power and auxiliary equipment (see Table 7 for more detail).
The same system was priced with dust collection house and one
complete spreader truck. This arrangement is designed for returning
the gin trash to the soil. The complete cost of this installation was
$26,252.50, or slightly less than that of the incineration system
(Table 8).
TABLE 7 —ESTIMATED COST OF TRASH-COLLECTING AND
TRASH-INCINERATING SYSTEM FOR 12-bale/hr GINa
Three in-line filter traps—to specifications (screen cages
may be substituted for price of $1,405.00) $ 4,125.00
Six sets twin cyclones—to specifications 1,966.00
One set quad cyclones—to specifications 639.00
One suction manifold for three lint traps 395.00
Cyclone stand for bank of cyclones on ground. Conveyor,
drives, motor, blowbox, tail pipes, etc 2,674.50
One 45-foot-diameter trash burner with cyclone mount
and cleanout doors—erected (est) 13,500.00
One complete set pipe elbows, etc, to connect pipe from
gin wall to incinerator (est) 3,150.00
Delivery and erection—trash collection system 2,600.00
Total cost trash-collecting and trash-incinerating system $29,049.50
«Capable of handling stripped-cotton trash.
Ginners vary in trash-handling methods from community to com-
munity, based upon outside pressures for dust control, the economic
Pendleton 41
-------
situation of the gin, and the prospects for continuation of a profitable
enterprise. As an aid to better understanding of the problem, the
Cotton Division of the U. S. Department of Agriculture has specially
prepared for this conference a table showing how gins dispose of the
gin trash. The fieldmen of the Cotton-Classing offices have personally
visited all the gins in the course of their cotton-classing and cotton-
marketing duties, and these figures are derived from their visits.
They indicate that approximately 37 percent of the gins incinerate
the trash, 58 percent return it to the land, and 5 percent handle it
in some other manner (see Table 9). The differences among neigh-
boring states in the handling of gin trash are interesting.
TABLE 8 — ESTIMATED COST OF TRASH COLLECTING,
HAULING, AND SPREADING SYSTEM FOR 12-bale/hr GINa
Three in-line filter traps—to specifications $ 4,125.00
Six sets twin cyclones—to specifications 1,966.00
One set quad cyclones—to specifications 639.00
One suction manifold for lint traps 395.00
Cyclone stand for bank of cyclones, etc 2,674.50
Trash hopper, cyclone, and auxiliaries 3,103.00
One complete truck spreader 7,000.00
Complete pipe from gin wall to system parts 3,150.00
Delivery and erection—trash system 3,200.00
$26,252.50
"Capable of handling stripped-cotton trash.
In looking at the gin trash and air pollution problems today,
every well-informed person must be impressed with the improve-
ments this industry has made in the last 20 years. Twenty years ago
many gins blew the trash on the ground for the entire harvest season,
then disposed of it as best they could by hauling or burning. Others
burned the burs and leaf trash in open pits or homemade, galvanized-
iron enclosures. There was no attempt, to my knowledge, to control
the dust and smoke nuisance, with but a few special exceptions.
Later, and particularly as cotton mechanization progressed, many
ginners built expensive incinerators in an attempt to deal with the
problem. And finally, the movement to return the trash to the land—
whether for agricultural purposes or for disposal—caught on with
the cotton ginners of West Texas. The Texas Agricultural Extension
Service and the Texas Cotton Ginners' Association deserve strong
commendation for leading this movement. The U. S. Cotton-Ginning
Laboratories deserve much credit for seeking out and adapting for
the ginners' needs the high-efficiency cyclone and the screen cage,
and especially for developing the in-line filter for the use of all the
people.
42 COTTON-GINNING WASTES
-------
This paper does not intend to imply that all gins today contain
the trash disposal equipment discussed. A trip through the Cotton
Belt at harvest time will show that some gins have no dust control
TABLE 9 — METHODS OF TRASH DISPOSAL AT
COTTON GINS, 1965-66 SEASON"
State
and
United States
Georgia
Alabama
South Carolina
North Carolina
Virginia
Florida
Louisiana
Arkansas
Mississippi
Tennessee
Missouri
Illinois
Kentucky
Texas
Oklahoma
Arizona
California
New Mexico
Nevada
United States
Incinerate
No.
18
74
—
9
—
1
156
359
244
83
150
—
2
573b
56C
28
14
27
—
1,794
%
7
20
—
4
—
17
73
69
40
32
99
—
67
43
37
19
5
38
—
37
Return
to
land
No.
246
224
256
189
6
5
59
142
280
176
—
2
1
719
77
117
285
44
1
2,829
%
92
62
100
91
100
83
27
28
45
68
—
100
33
55
50
79
94
61
100
58
Other
No.
4
64
—
11
—
—
—
14
89
—
1
—
—
33
19
3
3
1
—
242
%
1
18
—
5
—
—
—
3
15
—
1
—
—
2
13
2
1
1
—
5
Total
(100%)
No.
268
362
256
209
6
6
215
515
613
259
151
2
3
1,325
152
148
302
72
1
4,865
"Source: Cotton Division, Consumer and Marketing Service, U. S. Depart-
ment of Agriculture.
blncludes 70 gins that use both methods—incinerate and return to land.
Includes 19 gins that use both methods—incinerate- and return to land.
equipment. A careful study, however, will show that most gins have
made some improvements, and hundreds of gins have spent large
sums and have achieved an admirable degree of control. Many west-
ern area gins can be so described.
In summation, the methods of controlling gin trash and air pollu-
tion at gins are known and widely used today. These methods were
nonexistent a few years ago. They are expensive. Better and less
expensive methods are needed. I recommend that the vast experience
Pendleton
43
-------
and the controlled ginning facilities of the U. S. Cotton-Ginning
Laboratories be employed in an expanded program to seek solutions
to these problems. I also recommend that demonstration setups be
built at each regional ginning laboratory so that the state extension
services, the ginners' organizations, and health agencies can conduct
tours and educational clinics at these points and show the ginners
and others interested the latest and most efficient method of con-
trolling gin dust. I am certain more rapid progress can thus be made
in handling the age-old, expensive problem of air pollution at cotton
gins.
Summary of Open Discussion
Mr. R. J. Lewis of the State of Georgia remarked that ginners are
reluctant to return trash to the land because of its grass and weed
seed content.
In reply, Mr. F. Elliot suggested that conveying cotton trash over
a sand screen before spreading it can be effective in separating seeds;
composting before spreading might also be considered. In Texas,
composted cotton trash has a fertilizer value of $7.50 per ton and
results in increased lint yields of 25 percent for 2- to 4-ton-per-acre
applications. Larger applications of 6 tons or more per acre are
usually avoided because of increased handling problems and adverse
carbon-to-nitrogen ratios in the soil.
44 COTTON-GINNING WASTES
-------
METHODS OF COLLECTING LINT COTTON
TRASH
V. L. Stedronsky
Engineer in Charge
Southwestern Cotton-Ginning Research Laboratory
Mesilla Park, New Mexico
Agricultural Engineering Research Division
Agricultural Research Service
U. S. Department of Agriculture
Traditionally, cotton gins are dirty, dusty, smoky, and noisy.
That is why they are generally built in the country or far enough
away from communities to avoid creating a public nuisance. Cotton
gin businesses perform many services other than simply separating
the fiber from the seed. They may sell seed, fertilizers, and supplies;
act as the clearing house for exchange of implements, tools, machin-
ery, and labor; and become a voting place and the center of transact-
ing all kinds of business. The gin owner or manager soon finds
himself in the center of these activities and becomes a leader and a
central figure for his customers. Naturally, therefore, gins become
the center of agricultural activity for their areas. This tends to cause
people to migrate to the gin's location and results in a buildup of
homes and stores. These people move into these surroundings will-
ingly, well aware of existing conditions. They may participate in the
profits or otherwise benefit materially from the gin or associated
activities. These people are not often the source of public complaints.
More often, the complaints come from residents who have moved into
the area for other reasons, particularly since World War II, owing
to the expansion of urban communities. These new residents are
mostly concerned with the nuisance rather than the health hazard
aspects of their complaints.
The problem of collecting and disposing of gin trash generally
falls into two main areas. The first consists of dealing with the coarse,
heavier trash such as burs, sticks, stems, leaves, sand, and dirt, the
bulk of which is removed in the seed cotton-cleaning stages of gin-
ning. (Seed cotton means cotton with fibers still attached to the seed
as it comes from the field.) The collection of this material lends
itself to the use of cyclones because centrifugal fans have the neces-
sary pressure characteristics and are adaptable to cyclone use. The
collection of this type of foreign matter is not, a part of this discussion.
The second problem area is more difficult—that of collecting the finer
dust, small leaf particles, and fly lint that are discharged from the lint
after the fibers are removed from the seed.
Since 1952 the Mesilla Park Ginning Laboratory has been en-
gaged in a research program on the collection and disposal of gin
wastes. The problem of the disposal of the heavier trash was under-
taken first. This consisted of work on incineration, then on compost-
ing, and finally, with the cooperation of private industry and the
Stedronsky 45
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Texas State Department of Health, on the introduction of the small-
diameter cyclones to the industry.
Work on the second phase was begun about 1956, that is, the col-
lection of the finer types of foreign matter such as dust and fly. The
collection of this material is more difficult because it is emitted into
the atmosphere by large volumes of air under very low pressure. The
increasing use of two or more stages of lint cleaning, together with
the use of more suction condensers, has necessitated employing many
of these high-volume, low-pressure, propeller-type, vane-axial fans.
These fans have the needed characteristics for adequately performing
the required function in the ginning process. Modern gins can have
four, five, or more low-pressure fans in the lint-handling systems,
each discharging from 2,000 to 20,000 cfm air. They normally operate
under total resistance requirements ranging from 3 to 6 inches of
water pressure.
One of our first attempts at collecting gin waste was by use of a
settling chamber. One was designed and installed at a local gin.
This house was designed to receive approximately 28,000 cfm air from
a combination of high-pressure centrifugal fans and low-pressure
tube fans. It was 30 feet long by 24 feet wide by 16 feet high. It had
one partition baffle and a discharge area of 360 feet or a discharge
velocity of approximately 80 fpm. It performed very well, but outlet
velocities of less than 75 fpm are more satisfactory.
Generally, unsatisfactory performance of settling chambers re-
sults from their being too small, and very often, sufficient space for
the proper size of chamber is not available. One satisfactory installa-
tion was at the Hatch Co-op Gin. This gin got into trouble when the
town built a new grammar school on the edge of the gin yard, even
though the gin had been there for years. The difficulty was overcome
by converting the old seed house into a settling chamber and dis-
charging all the condenser vents into it. The gin manager reported
that it did a good job but was rather difficult to clean and also was a
fire hazard.
Concurrently with our efforts, other people in the industry were
trying to find a solution to collecting fine trash. The screen wire lint
cage first appeared at California gins about 1957. To the best of our
knowledge these cages were designed and introduced to the industry
by Mission Cotton Equipment and Engineering, Inc., of Fresno, Cal-
ifornia. California has for some time been more strict than other
states about safety and air pollution law enforcement. These cages
were a big step toward the control of lint fly emitted by lint cleaner
condensers and battery condensers. The use of these cages soon
spread from California to other areas and is now very common.
Nevertheless, the use of relatively coarse, ordinary window screen
wire of 14, 16, or 18 mesh coupled with the constant agitation of lint
fly, dust, and so forth permits considerable amounts of dust and fly
to escape through the screen wire. Another undesirable feature of
these cages is that they must be kept dry at all times. In areas where
46 COTTON-GINNING WASTES
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rains, showers, or heavy dews occur, these cages must be protected
with louvered skirts, or better yet, housed under a solid roof. Most
California gins now provide a screen-walled enclosure with solid roof.
This second screen outside the cages acts as a secondary collection
agent, and the screen walls accumulate additional fly and dust that
escaped through the cages. The walls are periodically brushed and
cleaned by the yard man. This is done perhaps once or twice a day,
or as needed. Apparently, some installations are more effective than
others.
Even though the lint cages were increasing in popularity, they
did not satisfy the requirement at all gins. Progressive ginners were
attacking the problem by other methods. One fine example of an
attempt to correct an individual problem will be described to you
here by Mr. Andrew O'Neal of the Community Gin Company of
Glendale, Arizona. Another pioneer is Mr. Jack Francis, owner of
the Valley Gin Company, Peoria, Arizona. He installed a very elab-
orate system of cyclones and filter bags at one of his gins. The results
of this installation seem to be reasonably satisfactory, but the system
is expensive, and maintenance costs are high. These and other efforts
by various individuals are making a big contribution toward helping
to solve the air pollution problem at gins. Their efforts are even more
admirable when we consider that they were done voluntarily and
at an expense of thousands of dollars with no motive other than a
conscientious effort to eliminate a nuisance in their communities.
In spite of all these efforts, however, these devices were evidently not
a complete solution to the problem.
In 1962 the Mesilla Park Ginning Laboratory began developing
a lint collection device that was efficient, economical, and generally
satisfactory for use at commercial cotton gins. Preliminary review
of dust collection principles revealed that a filtering device was
desirable and also that the potential for adapting commercially avail-
able bat-type filters did not appear encouraging. As the investigation
progressed, the idea of the in-line filter materialized. The objective
was to use a fine-mesh screen to stop the flow of foreign matter in
the airstream, and as it accumulated, have it become its own filtering
medium for collecting finer particles and dust. Woven-wire screens
were investigated. Brass and bronze screen wire strainer cloth of
14 x 18, 80, and 100 mesh were tried. They were found unsuitable
for practical use with low-pressure fans because the initial pressure
drop is too great. The next step was to find a
-------
on the screen. The fly that accumulates on the screen acts as a filter
to catch smaller leaf particles and dust. As the collected material
increases on the screen, backpressure is built up in the air system.
The amount of backpressure allowable depends upon the performance
characteristics of the fan, and the resistance of the equipment in the
gin system. When the backpressure across the filter reaches some
preset level, say 0.75 inch water pressure, the pressure-differential
switch closes the electric circuit, which starts the motor that drives
the wiping brush. A plain gin brush stick sweeps downward across
the surface of the screen, wiping away the collected material. The
material can be caught in sacks or conveyed away by other means.
The backpressure drops as the screen is wiped clean, and when it is
lowered to another preset pressure of, say, 0.3 inch water pressure,
the brush stops, and the collecting cycle starts over again. The col-
lecting process continues with intermittent starting and stopping of
the brush automatically, depending upon the degree of contamination
of the discharging air. The design and construction of the filter are
not difficult, and the sizing of screen areas is not too critical. The
sizes are determined by the volumes of air handled by the vane-axial
fans. Although the measurement of air volumes is not difficult, few
operators have developed the skill and ability to perform this task
satisfactorily. Manufacturer's performance tables for these fans are
usually sufficient to determine the air volumes handled by vane-axial
fans. Two important factors are to be considered in designing these
filters: First, the proper selection of bolting cloth mesh; second, the
proper shape of the housing, in order to minimize the pressure drop
due to shock loss of the incoming air. Our filters have been designed
for a pressure drop of 0.1 inch water pressure through a clean screen
and 0.2-inch pressure drop caused by the housing, making a total
pressure drop of 0.3 inch through the unit. Most of our filters have 70-
mesh screens because these seem to be the most practical and have
been satisfactory to date. We have also tried screens of 40, 60, 80, 105,
and 230 mesh. A 70-mesh screen has a free area of 54.9 percent,
with screen openings of 0.0106 inch or 269 microns. The resistance is
less than 0.1 inch with an air entrance velocity of 1,000 fpm. Filters
can also be designed for finer mesh screens and for face velocities of
from 750 to 1,280 fpm.
Complete design details are given in An In-line Air Filter for
Collecting Cotton Gin Condenser Air Pollutants. U. S. Department
of Agriculture Report No. ARS 42-103.
The in-line filter is very efficient. Tests have shown that, with
our testing procedure, a filter with 105-mesh screen collected, for all
practical purposes, over 99 percent of all lint fly and all foreign
matter particles larger than 165 microns, and 70 percent of all the
particles smaller than 165 microns, resulting in an overall efficiency
of 87 percent for the unit. This same relationship holds for 70-mesh
screens, but slightly larger particles are emitted at the beginning of
the collection cycle. Hence, wiping cycles should be kept to a mini-
mum, consistent with pressure losses allowable for any given system,
because the longer material is allowed to accumulate and the thicker
48 COTTON-GINNING WASTES
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the filter mat becomes, the more and the finer the dust filtered from
the discharging air. Our tests have shown that one-half (0.51) pound
of pollutants per bale is caught from machine-picked cotton in the
Mesilla Valley and 2% pounds from stripped cotton in the Lubbock
area. The in-line filter is the most practicable, economical, and
efficient device available to date for collecting these fine pollutants
in cotton gins. Research at the Mesilla Park Ginning Laboratory con-
tinues toward developing still other practical and adaptable devices.
Many gins have installed lint cages that can be modified and
covered with bolting cloth, equipped with a vertical shaft and wiping
brush, motor, and pressure switch, and thus be converted into a
vertical version of an in-line filter. We have one at Mesilla Park
that is installed on a condenser discharge. It has performed well this
past season. We feel that some minor changes need to be made in our
installation. Stoneville has covered gin condenser drums with bolting
cloth, and we have one at Mesilla Park. This is also a great aid in
reducing the emission of pollutants into outside air. We have another
experimental installation at a local gin. This is a centrally located
sheet metal dust house that receives the discharging air from all the
condensers. One wall is open but covered with bolting cloth screen
and equipped with mechanical wiping brushes. This system worked
well for a short time, but difficulties have been encountered owing
to flimsy construction and clogging of the link chains to which the
wiping brushes are attached. It seems feasible that these difficulties
can be overcome if necessary. Since, however, the individual in-line
filters are performing so satisfactorily, we shall probably not devote
much effort in the future to the further development of this cen-
tralized collection system.
We are also experimenting with the use of large-propeller ven-
tilating fans that are installed in the side of the gin house and exhaust
air from the inside. The fan discharges into an in-line filter, which
collects the dust and fly that normally float around inside the build-
ing. Our objective is to provide cleaner and cooler working conditions
for the gin crew. We are not yet able to report much progress on
this work.
Research on other phases of ginning investigations indicates good
possibilities of materially contributing to the solution of the air
pollution problem. The small-diameter-pipe trash-handling system
reported in ARS Bulletn 42-59 (U. S. Department of Agriculture)
can reduce outside air pollution. The use of pressure blowers instead
of centrifugal fans for conveying trash can reduce air volumes dis-
charged to the outside from approximately 5,000 to 600 cfm. Mate-
rials-handling research for conveying seed cotton, cottonseed, and
trash is underway at Mesilla Park. The air flotation principle of con-
veying in open or closed troughs will reduce the need for high-
pressure, centrifugal fans that emit high-pressure, turbulent air into
the atmosphere. Seed and trash conveyed by this method will reduce
power and air requirements, and could in many cases eliminate the
need for small-diameter cyclones.
Stedronsky 49
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Perhaps the most promising research is our experimental Mono-
flow ginning system, which has only one fan exhausting into the
atmosphere where conventional gins now have as many as five or six.
In the Monoflow system, the seed cotton-conveying air is drawn into
the system at the unloading telescope and follows the cotton through
the entire drying, conditioning, and cleaning process. The air is
cleaned by means of small-diameter cyclones and in-line niters,
reused, and finally cleaned before discharging into the outside atmos-
phere.
The lint-conveying air from gin stands, lint cleaners, and con-
densers is also cleaned, washed, and returned to the inside of the
gin house. With this system, dust and fly inside the building are
practically eliminated, and only clean air is discharged to the outside.
Since this new concept of the ginning process is still experimental,
there are no commercial installations yet, but very good dust control
was achieved this past season at the Mesilla Park Ginning Laboratory.
In summary, the problem of collecting air pollutants from cotton
gins is not new. Voluntary efforts by private industry, state and
Federal agencies, and ginning laboratory research have contributed
materially to improving the dusty and dirty conditions around cotton
gins and to reducing the gin nuisance to surrounding communities.
Devices and equipment for control of these emissions are now
available. They were not available 15 years ago, or even 5 years ago.
Progress has been made, and the prospects are good for even better
control in the future.
Summary of Open Discussion
Referring to the secondary bag collectors used in Texas, Mr.
Paganini stated that maintenance proved a problem and the bags
were never replaced. Although collection efficiencies can be high on
this type of collector, a properly designed bag-sock installation will
not exceed a filter ratio of 4 cubic feet of air per square foot of cloth.
Moreover, at a cost of $1.75 per cubic foot of air handled, bag-sock
collectors are expensive to install.
Mr. Stedronsky attributed the low-pressure-drop characteristics
of the stainless steel bolting cloth to the large free area (54.9%)
of the 70-mesh cloth that results from wire diameters of 37/10,000
inch.
50 COTTON-GINNING WASTES
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PROGRESS REPORT —AIR POLLUTION
STUDY OF COTTON GINS IN TEXAS
Otto Paganini
Chief, Air Pollution Control Program
Division of Occupational Health and Radiation Control
Environmental Sanitation Section
Texas State Department of Health
The day of the harvesting by handpickers of just the seed cotton
with a slight amount of trash is becoming a thing of the past in Texas.
The cost of and shortage of manual labor have contributed to the dis-
appearance of handpickers of cotton from the scene in most areas of
this state. In their stead are the faster machines—the spindle pickers
and the stripper units. Machine-harvested cotton contains from 150
to 1,000 pounds or more of trash. If the cotton ginner is to compete,
he must not only provide the means of separating the seed from the
lint but must also clean the trash, both plant and dirt, from the lint
fibers. In addition, he must provide the haulage units to enable the
grower to bring the cotton to the gin. He must perform this ginning
service in the relatively short time of 6 to 12 weeks. Further, he
must dispose of the voluminous waste removed from the cotton. In
a modern, high-speed gin, the processing of from 12 to 20 bales per
hour can result in from 1 to 10 tons of waste. The ginning operators
usually employ pneumatic conveying systems. These systems, with-
out properly designed and adequately sized collection devices, can
release every minute to the community atmosphere thousands of
cubic feet of air containing large quantities of entrained dust, lint,
trash, and some pesticide residues. These pollutants have on or in
them pesticides that may be harmful to humans and other organisms
in the areas surrounding the gins. Some of these pesticides are also
corrosive and may cause damage not only to living matter but to
physical objects. In addition, bacteria and fungi have been found
to a greater degree in the dust samples collected downwind from a
gin that is ginning cotton than have been found in the dust normally
present in the atmosphere over the community upwind from the gin.
Citizens are becoming more concerned about these large dust
concentrations and are objecting to them. In this state, some court
cases have been filed and won in which the plaintiff obtained relief
through an injunction stopping operations until adequate provisions
could be made to prevent the emission of the offending dust, trash,
and lint. In addition, one doctor, an allergist, has stated that the
dust, trash, and lint are harmful to his patients who have respiratory
diseases. The doctor, who practices in Abilene, definitely stated this
to be the case during cotton-ginning season in eight or more towns in
his area where cotton gins are operated. He has more asthmatic
patients during cotton-ginning season and he attributes this to the
dust, lint, and fine trash they are exposed to when the gins are
ginning cotton.
Paganini 51
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Most of the people who complain are not interested in putting a
gin out of business but in getting relief that will permit them to enjoy
life and their surroundings without the fear of serious injury to
their health, or destruction of their possessions. In addition, the
industry, through the Texas Cotton Ginners' Association, the state
and Federal Agricultural Departments, and Agricultural Extension
Services, have encouraged ginners to make improvements to abate
the emission of dust, lint, and fine trash from the gin operations.
The gin machinery manufacturers have not, however, expressed much
interest in providing equipment to prevent these emissions.
The Texas State Department of Health, through its Air Pollution
Control Program of the Division of Occupational Health and Radia-
tion Control, recognized the problem in the late 1940's, and in 1957,
published its first bulletin on the methods by which waste emissions
from cotton gins could be abated. This bulletin was revised in 1964.
In the summer of 1964, the Department of Health initiated a
study of the problem to determine the amount of cotton gin waste in
the form of dust, lint, and pesticide residues that may be present in
the community atmosphere of the areas around gins. This was done
with the cooperation and assistance of local health departments.
In 1964, four gin locations were selected: Robstown, West, Big Spring,
and Lubbock. In addition, one sample was collected downwind from
a cotton gin at Van Court that incinerated its trash.
This presentation summarizes what was done and found in the
first year of this study and presents some suggestions in connection
with the abatement of emissions from cotton-ginning operations.
With employment by the Division of additional personnel in the
summer of 1964, the study was begun, and with funds made available
through the Air Pollution Control Grant from the Division of Air
Pollution, Public Health Service, U. S. Department of Health, Edu-
cation and Welfare, in December 1964, the study was continued in
1965. These funds permitted the purchase of additional air-sampling
equipment and made greater sampling depth possible.
The objectives of the study were to:
1. Determine the nature and extent of air pollution in the af-
fected areas;
2. relate air pollution to its effects, such as harm to humans,
damage to vegetation and property, and other economic and
aesthetic losses;
3. determine the need for and feasibility of a control program;
4. determine the degree of reduction of pollutant emissions
needed;
5. conclude whether problems are of sufficient magnitude to
warrant study and research.
52 COTTON-GINNING WASTES
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High-volume, electrostatic precipitator, millipore, grab, and
bacterial air samples were collected upwind and downwind from the
gins. These methods were employed to examine the samples for dust
and lint to determine: (1) The amounts emitted, (2) the distance
from the gins of the areas affected by them, and (3) the types of
chemicals and bacteria present in the dust. Controls or baselines were
established by the collection of samples upwind from the gin.
In 1964 only four high-volume air samplers were available for
sampling the air for suspended particulate matter and arsenic. Two
samplers were placed downwind, while one was situated upwind and
one was used as a mobile unit. A total of 70 air samples of 2- to
8-hours' duration at all locations were collected. In addition, 130
samples of 1- to 2-hours' duration were collected. These samples were
collected over a 2- to 5-day period, and the samplers were moved at
times so that they would be in the downwind direction from the gin
at the time the samples were collected. Other samples were col-
lected with electrostatic precipitators and millipore niters, and par-
ticle counts and sizes were determined; bacteria samples were col-
lected on nutrient and blood agar plates by means of a General
Electric Electrostatic bacterial air sampler. These were incubated
and bacteria colony counts were made. Sterile millipore filters were
used to collect samples that were then placed in sterile buffered-
water solution, transferred to selective media, and incubated. Aero-
bacter aerogenes was isolated from these air samples. These bacteria
are said to cause the acute illness that sometimes occurs among cotton
mattress makers. The samples were analyzed also for fungi. Air
samples were collected upwind and downwind with all these methods.
The dust count and size determination were made by the Spencer
Bright Line Hemocytometer Counting Cell Method. In addition, the
samples were further analyzed for arsenic content. Samples were
taken from cotton in the wagons, from debris found on vegetation
in the general area of the gin, and from rafters.
In 1965, 8 additional units were made available, bringing the
total to 11. Nine were placed at fixed locations, one upwind and eight
downwind. The other two were used as mobile units. This permitted
greater coverage to determine how far downwind from the gin
cotton gin dust and trash could be found. Arsenic determinations
were again made as well as determinations of total suspended par-
ticulate matter. !
The samples of suspended particulate matter collected downwind
in 1964 contained from 39 to 76,000 micrograms of particulate matter
per cubic meter of air sampled, and from 0.01 to 141 micrograms of
arsenic per cubic meter of air sampled. The largest concentrations
were found close in to the gin (1 to 8 blocks). Concentrations in sam-
ples taken at distances greater than 2,500 feet from the gin were
nearly equal to background concentrations. Upwind samples varied
from 67 to 783 micrograms of particulate matter per cubic meter of
air. In general the upwind samples had less than 128 micrograms per
Paganini 53
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cubic meter of air. In 1965, over 450 high-volume air samples and
50 grab samples were collected. The results of this phase of the
study will appear in a final report.
The bacteria and fungi counts in samples taken upwind were 88
to 100 and 33 to 70 per cubic meter of air, respectively, when col-
lected on nutrient agar. The counts in samples taken downwind
ranged from 172 to 1,752 and 19 to 129 per cubic meter of air,
respectively.
Blood agar bacteria and fungi counts in samples taken upwind
were 82 and 87, and 24 and 26 per cubic meter of air, respectively;
bacteria and fungi counts in samples taken downwind were 285 and
248, and 22 and 57 per cubic meter of air, respectively. Two samples
of Aerobacter aerogenes taken upwind, were negative while two taken
downwind were positive.
In the 1964 phase, a review was made of the number and loca-
tion of deaths that occurred in West. Deaths for the period 1961
through 1963 were analyzed by our Vital Statistics Section. There
was a definite increase in deaths in the winter months, which could
be expected; however, this same increase showed itself in the summer
months and could be in part due to hot weather. Our Vital Statistics
Division informs us, however, that more deaths occur in the winter
than in the summer. Of the 120 people who died in West during this
period, 47 were residents of the area downwind (prevailing) from the
gin and represented 39 percent of the total deaths, and this area con-
tained only about 25 percent of the population. The death rate in
this community (age-adjusted rate) is 894.2 per 100,000 as compared
with a state rate of 846.8 per 100,000 for the period 1961 through 1963.
The air-sampling period during the 1964 phase varied with the
gin operation and ranged from V2 to 24 hours over a 3-day period.
In 1965 the sampling period was extended to 24 hours over a 5- to
6-day period, with mobile sampling for periods of % to 2 hours. In
addition, in 1964, air sampling included analysis for suspended par-
ticulate matter, dust particle size and counts, bacteria and fungi, and
pesticides. In 1965, samples were analyzed only for suspended par-
ticulate matter and arsenic.
This study was begun in the last part of August 1964 at Robs-
town, Texas, through the cooperation of the Corpus Christi-Nueces
County Health Department. Other areas studied were West, Van
Court, Big Spring, and Lubbock. In 1965, the areas studied were
Lazona and San Benito in the lower Rio Grande Valley, and again,
West, McKinney, and Ellinger.
In 1965, except for the mobile samplers, the fixed sampler sites
operated 24 hours. The gins did not operate continuously throughout
the 24 hours during which most of the samples were collected. There-
fore, the loadings would be less on a microgram-per-cubic-meter
basis.
54 COTTON-GINNING WASTES
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Six conclusions were reached from the study.
1. Smoke emitted from incineration of cotton gin waste was
found to contain significant amounts of benzene-soluble or-
ganic matter and arsenic, and to reduce visibility to such an
extent at times in some locations that driving was hazardous
on the highway. In addition, these smokes are acrid, and
reports have been received that they and the dust and lint
are a hazard to the health of individuals, particularly of those
who have respiratory involvements. Texas A&M University
Report MP 771, June 1965, Study of Arsenic Acid Residues
on Cotton states: "The amount of arsenic which would be
expected to escape in fumes from burning of such trash would
be essentially three pounds of arsenic per ton of trash burned
. . . The release of arsenic in the fumes during combustion
of leaf trash implies that burning of gin trash with high
arsenic content poses one of the potentially most hazardous
situations encountered in the study."
2. Dust and lint concentrations in the air have been found to be
excessively large and much greater than the ambient air
standards set by some states.
3. The areas affected downwind reached about % mile.
4. Bacteria and fungi are present in greater amounts in the air
sampled downwind from gins than in those sampled upwind.
One type isolated was Aerobacter aerogenes.
5. Concentrations of arsenic, pesticides, and defoliant exceeded
many times the concentrations found in the natural ambient
air.
6. Abatement of dust and lint to a safe concentration at many
gins is still a desire and not fact. A concentration of 125
micrograms or less per cubic meter of air sampled at the
property line of a gin is recommended at present, based upon
this and other similar studies. A smaller concentration may
be advisable as more information becomes available, espe-
cially on pesticides other than arsenic.
There appears to be a definite need for better control of emissions
at gins. High-efficiency cyclone collectors appear to be required to
handle more material than is normally expected of these units. These
were originally intended for use when trash per bale was around 150
pounds maximum and 4 to 7 bales of seed cotton was being ginned
per hour.
The remarks that follow are no reflection on any group asso-
ciated with the cotton production and ginning industries; however,
since I have long been on the scene with the problem at hand, I wish
to make these comments. Again, before I do, let me point out that
the U. S. Department of Agriculture has contributed in part to the
solution of the problem by their work and their ideas. Even though
their prime missions are to improve and obtain maximum yields of
cotton from the soil and seed, and produce a good quality of cotton,
Paganini 55
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they have devoted time that could have been spent on their major
missions to help abate the problem of emissions from gins and we are
grateful.
The Texas Cotton Ginners' Association has made considerable
effort to recognize the problem by pointing it out to its members and
to others and encouraging them to do something about it. Their bul-
letin What We Know About Air Pollution is one of their contributions
to the solution of the problem.
Then there is our own contribution, the Texas State Department
of Health OH-2 Bulletin No. 2 Control of Cotton Gin Waste Emissions,
first issued in 1957 and revised in 1964. Copies may be had by writing
the Texas State Department of Health, Austin, Texas. This bulletin
needs, however, to be revised again because of the information we
have gathered.
One group that, in my opinion, has done little to control emis-
sions created in the operation of equipment consists of the manufac-
turers of ginning equipment. These people know well, or should
know, air- and trash-handling capacities of their equipment and
could develop adequate control devices from information at hand
on methods that may be employed to prevent emissions of dust, lint,
and gas. In their stead, this has been left to the manufacturers of
auxiliary equipment who do not have the benefit of this information.
Some of this latter group have done some fine work toward abating
emissions.
If at all possible, and many ginners would prefer and welcome
it, I believe, the trash should be left in the field. We and the Texas
Cotton Ginners' Association prefer this, because of the benefits the
trash returns to the land.
We understand that the cleaning of cotton in the field poses a
problem, which has been cited previously by others. One manufac-
turer hopes, however, to develop in the near future a unit that will
pick and clean the seed cotton in the field.
We think that we can eliminate the problem of dust and lint
emission at the gin. Our close association with the problem leads us
to think that efforts to eliminate it must be given greater emphasis.
Today seed cotton brought to gins contains an average of 700 pounds
of trash per bale, and the gins have capacities of ginning 7 to 25
bales per hour with an average of perhaps 12. These efforts must
begin with the coming ginning season. Already, in Texas, persons are
bringing this matter before the Texas Air Control Board for hearing,
and out of this may result development of rules and regulations to
require gins to abate the emissions of these pollutants.
In closing, let me philosophize a bit. The ginner, who must man-
age the gin and pay the bills, is in a competitive business, and like
all of us, wishes to obtain a profit from the services he performs. We
must, therefore, treat ginners as individuals. We in the governmental
service and enforcement groups can, by proper persuasion and educa-
56 COTTON-GINNING WASTES
-------
tion in our contact with ginners, go a long way toward abatement of
this air pollution problem.
Summary of Open Discussion
Mr. Paganini first discussed some problems of dust emission from
a cyclone collector at a gin in the Lubbock, Texas, area. He specu-
lated that perhaps the screw conveyor serving the cyclone's trash exit
may not be removing accumulated trash fast enough and thus may
be causing flow disruptions in the cyclone itself. One possible solution
to this problem might be to install a surge box between the cyclone
exit and the auger feed to handle periods of overload or unusually
dirty cotton.
Mr. T. Wimberly, confirming these remarks, stated that he could
forecast the extent of fine-dust emissions from cyclone dust collectors
by merely estimating the trash content of incoming trailer cotton.
Trash contents of as much as 1,800 pounds per bale are usually ade-
quately handled so that no visual emissions occur. Trash loadings,
however, of 2,000 pounds per bale or greater seem to exceed the
capacity of the cyclone, and it emits great quantities of dust.
In answer to another question concerning the state of arsenious
acid emitted from cotton gins, the speaker expressed the opinion that
the arsenious acid crystal is present on the cotton trash particles.
Vegetation damage from this heavy metal acid occurs when the acid
crystal contacts moisture in the air or on the plant. In the preceding
report, arsenic was reported as arsenic trioxide.
The following letter was read by the speaker in answer to a
question from the floor on whether cotton gin emissions constitute a
health hazard:
April 20, 1966
Air Control Board
Texas State Department of Health
1100 W. 49th Street
Austin, Texas
Attn: Mr. Wimberly
To Whom It May Concern:
This is to confirm in writing the conversation, which I had on
April 18, 1966, with Mr. Wimberly of your Department concerning the
extremely harmful effects produced particularly against children with
asthma by cotton gins in our area. I see patients from all over West
Texas, as far north as Crosbytown and as far west as Clovis, New
Mexico, and Odessa, and as far south as Pecos and Fort Stockton. It
would be easy to go through the files and find literally dozens of cases
that are easily controlled with minimum amounts of medication and
regular hypersensitization injections for pollen dust, molds, and
Paganini 57
-------
spores etc., until the cotton gins begin operating in the fall. It is
impossible to put into an injection everything to protect them against
the extremely irritating effects of lint, dust, and smoke from cotton
gins. Anything which can be done to minimize the air pollution from
this source will be of real service to the asthmatic patients in this area.
I would be happy to cooperate in any way in furthering this objective.
Signed,
David F. Pugh, M.D.
Diplomate, American Board of Pediatrics
Associate Fellow, American Academy
of American College of Biology
58 COTTON-GINNING WASTES
-------
THE OUTLOOK FOR DEFOLIANTS AND
PESTICIDES
Fred C. Elliott
Extension Cotton Specialist
Texas A&M University
There is more interest in mechanical stripper harvest of cotton
in Texas and Oklahoma than in the other cotton-producing states,
which are concerned first with spindle packing.
Almost three-fourths of the 1965 Texas cotton crop was stripper
harvested, desiccants being the preferred harvest aid chemical. This
leaves nearly one-fourth to be harvested by spindle picking, the
main interest being in the true defoliants. The leaflet L-145, Cotton
Defoliation Guide -for Texas, is supplied to growers by the Agricul-
tural Extension Service through the County Agricultural Agents.
Their 1965 annual reports showed that 56,465 farms used desiccants
or defoliants in 167 counties.
Table 10 shows the extent of use of defoliants and desiccants in
cotton harvesting in Texas.
TABLE 10 —EXTENT OF USE OF DEFOLIANTS AND
DESICCANTS IN COTTON HARVESTING IN TEXAS,
1962 THROUGH 1965
No. of No. of
Year farms counties
1962 82,219 164
1963 56,967 174
1964 60,879 166
1965 56,465 167
Table 11 gives the number of pickers and strippers in use in
Texas from 1947 through 1965.
These machines harvested about 94 percent of the Texas crop.
In the near future, as we approach total machine harvesting, the
division will likely be as follows: About three-fourths to be stripped
will require a desiccant or frost, and one-fourth to be machine
picked will require true defoliants when a harvest aid chemical is
used.
In 1966 the total acreage allotment is 6,520,211 acres, on 125,914
farms. As of March 25, 1966, a total of 99,189 farms had signed to
divert 1,736,236 acres from their allotted 5,456,027 acres. The final
signing shows 1,996,042 acres to be diverted from the 6,326,733 acres
allotted to those signing.
Elliott 59
-------
TABLE 11—NUMBER OF PICKERS AND STRIPPERS USED
IN TEXAS, 1947 THROUGH 1965
% % Total %
Spindle machine No. of Stripper machine No. of machine
Year pickers picked counties harvesters stripped counties harvested
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
19
92
335
255
767
1,122
1,557
1,532
1,547
1,618
1,587
1,831
3,280
4,505
4,782
6,777
5,381
5,864
6,498
3
3
3
3
2
4
10
14
14
19
18
20
22
13
23
69
63
72
74
83
78
70
68
57
78
100
110
106
103
92
86
88
3,443
4,523
7,003
7,138
14,127
14,270
15,088
18,877
19,524
20,698
23,132
26,692
29,236
32,042
33,089
37,540
40,921
41,512
45,232
21
18
21
22
35
31
34
44
51
58
62
70
72
58
61
84
72
109
119
130
133
130
117
123
133
143
152
151
159
168
167
173
24
21
24
25
37
38
44
58
65
77
80
90
94
In addition, most of the crop in Oklahoma is likely to be ma-
chine stripped. Parts of New Mexico and Arkansas are also inter-
ested in stripper harvesting.
Currently there is a need for approximately enough desiccating
material to prepare about 3 million acres of Texas cotton crop for
stripper harvesting.
The spindle picker is operated in the lower Rio Grande Valley,
along the gulf coast, up through the river bottoms of central Texas,
and in the western irrigated areas in the Pecos and El Paso Valleys.
The maximum acreage requiring the use of true defoliants would be
about 1 million acres.
Stripper harvesting machines are used on the high plains and
rolling plains, the uplands of central Texas, and the Blackland area,
and into the nonirrigated areas of south Texas. Formerly, stalk size
was one of the main points determining whether or not growers de-
sired to use stripping machines rather than the spindle picker. This
has partially changed, however, because of the brush stripper. The
brush machine strips a larger stalk. It also permits stripping under
slightly damper weather conditions.
Furthermore, the stripper is more efficient in regard to the per-
cent of crop harvested. In Texas we can easily attain a 98 percent
60 COTTON-GINNING WASTES
-------
efficiency with the stripper harvester. Moreover, further develop-
ments of the stripper are underway.
We urgently need, therefore, a desiccant that will prepare the
cotton for the stripping machine. It should have a regrowth inhibitor
and, further, it should be as nontoxic and noncorrosive as possible if
the price is right. At present, arsenic acid is approved. Chlorates can
be used at the upper limits for desiccation. Still other materials are
in the developmental stage.
Often, on the high plains, cotton can be planted early and can
reach maturity early enough so that it can be desiccated and stripped,
even in the latter part of September. Certainly, large acreages can be
desiccated in October—as much as 1 month ahead of the annual
first-frost date. This prevents cotton from staying in the field and
taking weather damage, which reduces the fiber qualities.
Desiccation and early stripping also greatly reduce cotton insect
populations the following year. In the central Texas Blacklands, the
bollweevil is being drastically reduced by a program of desiccation
and machine stripping.
Practically all the manufacturers of cotton-stripping machines
have added a green-boll separator and are building excellent ma-
chines. The basket has been added to the stripper. This reduces the
harvest labor about 50 percent. Under the best operating conditions, a
green-boll separator can take out most of the green bolls and imma-
ture bolls that may be killed by frost or injured by insects.
Moreover, a number of companies have a very active research
and development program underway to remove burs in the field.
Since the green bolls can be separated out, this opens up a new
possibility of bur extraction in the field. The experimental models
of these machines look very promising indeed.
The green-boll-separating devices have been adapted from the
USDA research models. This work was started at the Agricultural
Experiment Station at Lubbock, Texas. These green-boll separation
devices take fully 96 percent of the green bolls that might be in the
cotton.
The need for a suitable desiccant is evidenced by the fact that
growers are stripping about three-fourths of the Texas cotton crop
with over 45,000 machines operating in 173 counties. A stripper is
more efficient and economical than the spindle picker. Two row
spindle pickers sell for about $20,000. A stripper sells for $3,000 to
$9,000, depending upon the model and whether it is self-propelled.
Currently, machines to strip cotton handle larger stalks than formerly.
The brush stripper also handles cotton under somewhat damper con-
ditions than the steel roll machine. At present this would mean a
potential of approximately 3 million acres that could be stripped in
the state of Texas. The acreage in Oklahoma, New Mexico, and
Arkansas could be added to this. Two companies sold 1,200,000 gal-
lons of arsenic acid for preparation of the 1965 crop for stripping.
Elliott 61
-------
Where cotton can be stripped before frost, the use of a desiccant
is an absolute must. There is no other way. True defoliants cannot
be used. At the McGregor Experiment Station it has been shown
that not more than 4 percent green leaf can be permitted if full-
quality potential is to be obtained.
Other pesticides necessary for profitable cotton production are
fungicides, insecticides, herbicides, and fumigants for nematode
control.
Fungicides are used to control seedling diseases such as damping
off and reduce bacterial blight. These materials are used to treat the
planting seed or as in-the-furrow application at planting time.
Insecticides are needed to control a large number of insects in
cotton, from soil insects at planting to bollworms or leafworms
shortly before harvest.
In 1964 the economic loss to Texas cotton growers from weeds
was $58,715,781. The cost of controlling weeds in Texas cotton fields
was more than $25 million. The sale of herbicides for this purpose
exceeded $8 million. The ever-increasing scarcity of farm labor, and
the progressive demand for higher efficiency on fewer acres is ex-
pected to stimulate almost universal use of herbicides for controlling
weeds in this crop within the next few years.
62 COTTON-GINNING WASTES
-------
THE COMMUNITY GIN COMPANY'S TRASH
COLLECTION AND DISPOSAL SYSTEM
Andrew O'Neal
Superintendent
Community Gin Company
Phoenix, Arizona
Four or five years ago we were faced with the problem of clean-
ing up the dust emitted from a gin in Scottsdale, Arizona; the system
that we designed at that time has been operating ever since. You
can imagine our dismay when we found that a housing development
was being built within 150 feet of our gin plant. Since the land we
occupied was very expensive, we probably could have sold the real
estate for enough money to move the gin, but the only way we could
move was east—into an Indian reservation. We talked to those people
about a site, but found this alternative unattractive. Hence, we pre-
ferred to eliminate the dust, thinking it would be cheaper than
moving the gin and finding new customers.
We first made simple tests upon the amount of dust or lint that
we would have to handle and dispose of. We made these tests with a
standard high-efficiency cyclone and found that, under severe condi-
tions, we might have to trap and dispose of 250 pounds of dust per
hour. This represents trash loadings of ground pickup cotton under
very rough conditions. About 90 percent of our ginning is spindle-
picked cotton, and we estimated that we might have to collect about
75 pounds of dust per hour from that type of ginning. This total
discharge includes the motes, handling system, and the condenser
discharges as well as the main trash line. The gin stand has 490 saws
with a capacity of 6 to 11 bales an hour, depending upon the condition
of the cotton.
A local sheet metal fabricator explained to us that an enclosed
cyclone would do a better job on the fines. His experiences were with
hay and oil mills; we ran a simple test on this type of cyclone and
found an appreciable reduction in the emissions. We estimated about
half the emission figures that I have quoted earlier, or 125 pounds per
hour for trashy cotton and 30 to 35 pounds per hour on good machine-
picked cotton.
We decided to use a water injection system for two reasons:
(1) We discovered how to inject the water before the second cyclones;
(2) disposal would be more practical when the dust was wet than
when it was dry. I have two or three thoughts about disposal; I
thought it would be easier to plow under a truckload of slurry or
slush than a truckload of dust. One could also dump the slurry in an
irrigation ditch or on the desert and it would dry up to a sort of cake.
In our particular case we were using the old type of bale yard storage
with 2,500 to 5,000 stored in a yard; I thought that we could hold the
dust down on the roadway by using this dust slurry. I say slurry
O'Neal 63
-------
because we do trap this dust in water and have to change the water
often. The only problem with this technique was the odor, which we
were able to control economically with moderate amounts of DK
powder. Since then, we have abandoned the bale yard storage system
and have found that the slurry is of definite advantage in trash com-
post piles; it seems to accelerate the decomposition of the gin trash.
Bur and trash disposal in our area is becoming an expensive
problem. In most cases, our growers are just not interested in going
to the expense of spreading gin trash back on the land, even though
they understand the fertilizer and humus value. Probably hay and
grain crop rotation along with other crop rotations is more valuable
to them since these are cash crops. The farmer also feels that weed
seed would be expensive to control, especially the morning glory.
We are exploring compost for the retail market; I shall explain that
later in more detail.
The following equipment has been constructed in series: (1) A
large-diameter cyclone with vacuum dropper box at the trash outlet to
allow operation of the cyclone under negative pressure; (2) an 8,000-
cfm paddle blade with a 19-inch water pressure drop across the fan,
and a 2-inch water pressure after the fan; (3) a %-inch water pipe
inserted into each of the inlet lines; and (4) a pair of high-velocity
cyclones for collection of the fines. I think you can imagine the
scrubbing action that the dirt gets in this wet cyclone.
We find it necessary to use 5 gallons of water per minute (gpm).
This water is recirculated until it becomes too dirty as a cleaning
agent and then we pump it out of the sump and replace it with clean
water. We find that a %-inch pipe, inserted in the galvanized water
pipe, is a satisfactory device for water injection. We even tried
nozzles at that point, hoping to get a better spray, but these were not
as successful as the simple injection system.
I should like to answer Mr. Paganini's question about the particle
sizes emitted: The only measurement we have is the number of phone
calls we get. We simply do not have a method yet; I should also like
to find what is coming out of that cyclone. This system might be
expanded to industry. It could possibly be compounded and two
wet-type cyclones used under really severe conditions, and we could
probably pull through both of them with one fan. As the engineers
know, we are probably reaching the limits of paddle blade fans at
these pressures. There is, however, one fan manufactured that, I be-
lieve, will go to 45 to 50 inches of static water pressure. A liquid
could be used that is compatible with some other reclaimed material,
and perhaps a centrifuge could be used to reclaim valuable materials
from the slurry.
Our lint condenser systems are equipped with the lint cages
described on the first day of the symposium; the first condenser after
the gin stand is double screened—the lint cage being one screen and
the wire-enclosed house the second screen. We have had very good
results with these lint cages and we are sold on them entirely; the
64 COTTON-GINNING WASTES
-------
maintenance is very low, and the lint coming out seems to settle in
45 to 50 feet on the ground, as a result of the low screen velocities.
Summary of Open Discussion
In elaborating upon the details of his wet-cyclone dust collectors,
Mr. O'Neal explained that the pipe is injected into the inlet line
about 10 feet from the high-efficiency cyclone entrance. The dust-
water slurry discharges directly into a sump tank, where settlement
of the suspended dust occurs; the water is then recirculated for
further use. Because of sludge buildup in the sump, the water must
be replaced with 900 gallons of fresh water after 500 bales of
machine-picked cotton have been ginned. In states such as Texas and
Oklahoma, there would admittedly be an icing problem during the
cold winter months, but this could probably be overcome by use of
an underground sump and heating element.
When questioned about mud caking problems in the cyclone, Mr.
O'Neal stated that, as long as an adequate water flow of 5 gpm or
more was maintained, no caking problems were encountered, even
with very trashy cotton.
For the large-diameter cyclone that collects most of the bur sticks
and coarse particulates, a screw conveyor serves the cyclone trash
outlets. From the screw conveyor, the trash is conveyed to an in-
clined chain drag elevator for loading onto the trash trailers. Just
above the trailer, two hanging canvas flaps help to prevent fine dust
from dispersing during loading operations. These flaps are weighted
to ensure stability even during strong winds.
While this system costs $20,000, it was felt that a new dust
collection system could be built at a much lower cost.
In elaborating upon the composting system he employes, Mr.
O'Neal explained that the cotton trash is piled in 100-foot-long by
10-foot-wide by 4-foot-high piles and watered for 24 to 36 hours to
initiate the composting process. Trenches along each side of the pile
return drainoff water to a central sump from which it is recirculated.
Occasionally, turning of the piles dissipates the heat of decomposition
and prevents temperatures from exceeding 130°F. The purpose of
the composting studies has been to produce a marketable compost
that has a decent shelf life.
O'Neal 65
-------
PRACTICAL CONSIDERATIONS IN THE DESIGN
AND OPERATION OF THE IN-LINE FILTER
Travis C. McLain
Project Engineer
Research and Design Division
Continental/Moss Gordin, Inc.
Prattville, Alabama
INTRODUCTION
The in-line filters that are the object of this report are located
at the Honey Island Gin Company in Kruger, Mississippi, and at the
Experimental Department of Continental/Moss-Gordin, Inc., Pratt-
ville, Alabama. There are three filters at Honey Island Gin Company,
each filtering the discharge air from one 26-inch vane-axial fan. Each
fan supplies the suction for two lint cleaner condensers mounted
behind a 16-inch-diameter, 119-saw brush gin (Figure 12). The
volume of air cleaned by each filter is approximately 8,500 cfm. The
single in-line filter at the Continental/Moss-Gordin Experimental
Plant cleans the air from one 21-inch vane-axial fan. This fan sup-
plies the suction for a one lint cleaner located behind a 16-inch
diameter, 79-saw brush gin (Figure 13). The volume of air cleaned
by this filter is approximately 2,200 cfm. The three filters at Honey
Island Gin Company have been in operation for two full seasons,
while the filter at the Continental/Moss-Gordin Experimental De-
partment was installed for test purposes only. All the experimental
data contained herein were obtained from one or both of these two
installations.
16-in-diameter,
119-saw gin
16-inch-diameter, 26-inch-diameter 40-inch-wide
lickerin saw lint cleaners vane-axial fan in-line filter
Figure 12 — Continental/Moss-Gordin, Inc., in-line filter installation. Honey Island Gin Co.,
Kruger, Miss.
McLain
67
-------
16-in-diameter
79-saw gin
12-inch-diameter, 21-inch-diameter 40-inch-wide
lickerin saw lint cleaner vane-axial fan in-line filter
Figure 13 — Continental/Moss-Gordin, Inc., in-line filter installation, Continental/Moss-
Gordin Experimental Plant, Prattville, Ala.
DESIGN CRITERIA
The in-line filter, designed and built by Continental/Moss-
Gordin, Inc., was constructed with five goals in mind: The filter
would have to remove as much as possible of the lint and dust from
the condenser exhaust air, would be available to the gin. owner at
the lowest possible price, would require the least amount of mainte-
nance, would operate cheaply, and would require a minimum amount
of time for making on-the-spot repairs or replacements. The first
goal, efficient filtering action, was relatively simple to achieve, as a
result of extensive research work done by the U. S. Department of
Agriculture on the in-line filter (1). The last four, however, were to
determine finally the actual working design of the filter.
Because mass production is the key to low prices, it was decided
that only one size filter would be designed and built. This would
enable the factory to manufacture the filter in the most economical
lots at the lowest possible cost without sacrificing quality and long life.
Based on design information and recommendations of the USDA,
it was decided that the filter screens to be tested would be 40- x 40-
and 105- by 105-mesh, stainless steel, bolting-grade wire cloth. More-
over, the face velocity at the filter screen would not exceed 1,000 fpm
under the maximum volume of airflow that could normally be ex-
pected. This was done to ensure that the exhaust fans would not be
subjected to pressure sufficient to cause a backlash at the gin stand.
The maximum cfm value used was 12,000, and this figure used with
the available design information resulted in a 40-inch-wide separator
with 24- x 40-inch rectangular inlet and discharge openings. The
screen had 11.7 square feet of open area with a radius of 2 feet and
an arc of 120 degrees (Figure 14).
68
COTTON-GINNING WASTES
-------
Figure 14 — Continental/Moss-Gordin, Inc., 40-inch-wide in-line filter.
The pressure differential across a 40- x 40-mesh screen in this
housing with an airflow of 2,200 cfm is approximately zero, and with
an airflow of 8,500 cfm, is 0.05 inch of water. With 105- x 105-
mesh screen, the pressure differential is 0.02 for 2,200 cfm and 0.25
inch of water for 8,500 cfm. The vane-axial fans producing the
airflows mentioned actually deliver 3,700 and 10,100 cfm, respectively.
The difference between 3,700 and 2,200 cfm and between 10,100 and
8,500 cfm is the volume of air flowing out the bottom of the filter
through the lint and dust discharge opening into the trash pickup
line. The backpressures created by these two sizes of screen do not
exceed the additional %-inch water gage backpressure that propeller-
axial-flow fans can withstand, or the %- to %-inch water gage back-
pressure that vane-axial-flow fans can withstand.
I
The screen first tested in the filter installed at the Continental/
Moss-Gordin Experimental Department was the 40 x 40 mesh. Ma-
chine-picked and machine-stripped cotton was ginned in the 16-inch-
diameter, 79-saw brush gin, and the length of the cycles and the
effectiveness of the filtering action obtained were observed and
recorded. These data are presented graphically in Figures 15 and 16.
The 105- x 105-mesh screen was then placed in the filter, and ma-
chine-stripped and machine-picked cotton was ginned. Figure 17
shows the results of the test with machine-picked cotton. No graph
McLain
69
-------
was made of the test with machine-stripped cotton because the fly
collected so quickly on the screen that the wiper motor was energized
almost continuously. These tests made us aware of some important
points that are helpful in the selection of the size of the filter screen
to be used.
5
c
1.4
1.2
LJ
-------
mine the mesh of the filter screen. Since the method of harvesting
the cotton being ginned determines the amount of lint fly in the dis-
charge air, it was decided that the predominant method of harvesting
the seed cotton in the area in which the filter was to be located would
determine the mesh of the filter screen. Figures 15 and 16 and the
USDA publication aided us in determining that 40- x 40-mesh screen
should be used in filters to be located in areas where the predominant
method of cotton harvesting is machine stripping. Figure 17 aided in
selecting 105- x 105-mesh screen for filters to be located in areas
where the predominant methods of cotton harvesting are machine
picking and handpicking.
1.4
. 1.2
UJ
LJ
CC
I
1.0
LL.
Q
0.8
PRESSURE SWITCH
ACTIVATED
UJ
UJ
0.6
m
UJ
0.4
uj
OL
0.
O
0.2
GOOD FLY AND
DUST REMOVAL
GOOD FLY RE-
MOVAL BUT POOR
DUST REMOVAL
1.0 1.5
LENGTH OF CYCLE, min.
2.0
2.5
Figure 16 — Length of cycle and effectiveness of filtering action of 40- by 40-mesh, stainless
steel, boiling-grade, wire cloth screen on machine-stripped cotton.
McLain
71
-------
Z
UJ
UJ
a:
o
a.
UJ
<
z
tn
3
<
H
UJ
UJ
LU
m
ui
ct
UJ
a:
a.
B
OJ
GOOD FLY AND
DUST REMOVAL
GOOD FLY RE-
MOVAL BUT POOR
DUST REMOVAL
1234
LENGTH OF CYCLE, min.
Figure 17 — Length of cycle and effectiveness of filtering action of 105- by 105-mesh,
stainless steel, boiling-grade, wire cloth screen on machine-picked cotton.
The Honey Island Gin Company is located in the Mississippi Delta
where the majority of the cotton crop is handpicked and machine
picked; therefore, the niters located there have 105- x 105-fnuesji
screens. Figure 18 shows the length of the cycles and the effective-
72
COTTON-GINNING WASTES
-------
ness of the lint and dust removal* observed at Honey Island. The
results obtained from the Honey Island test upheld the conclusions
reached at the Experimental Department, that is, the mesh of the
filter screen should be determined by the predominant method of
harvesting in the area in which the filter is to be located.
Ul
UJ
tt
o
tn
1.4
1.2
1.0
D
z
ui
UJ
0.8
0.6
Ul
tfi
0.4
tn
in
ui
CC
0-
0.2
GOOD FLY
REMOVAL BUT
POOR DUST
— REMOVAL
PRESSURE SWITCH
ACTIVATED
GOOD FLY AND
DUST REMOVAL
0.5 1.0 1.5
LENGTH OF CYCLE, min.
2.0
2.5
Figure 18 — Length of cycle and effectiveness of filter action of 105- by 105-mesh,
stainless steel, boiling-grade, wire cloth screen on machine-picked and handpicked cotton
at Honey Island Gin Co.
•Effectiveness of lint and dust removal determined by visual observa-
tion.
McLain
73
-------
OPERATION
To help simplify the pressure switch connections necessary for
the filter to operate, the pressure rise between the condenser exhaust
fan and the filter screen was used to activate a pressure-sensitive
switch instead of the pressure differential across the screen. This
method meant only one pressure tap connection in the filter housing
instead of two. Continental/Moss-Gordin, Inc., uses two pressure-
sensitive switches to move the gin breast out of ginning position when
either of these switches registers a pressure rise in the gin flue or
the lint flue caused by a choke in one of the lint cleaner condensers.
For this reason the pressure switch connected to the filter has to be
adjusted so that the screen is wiped clean before sufficient pressure
is built up on one of the pressure switches in the flues to activate it
and move the gin breast out.
The backpressure caused by the bat of lint fly and dust collected
on the filter screen is relieved almost instantly when the wiping
brush begins to wipe the screen. To ensure that the arms make sev-
eral complete revolutions and that the screen is cleaned completely,
the pressure switch activates a time delay relay instead of the wiping
motor. The time delay relay is adjusted so that the wiping motor
runs long enough to rotate the wiping arms three revolutions. Hence,
even though the backpressure is relieved before one revolution is
completed, the timer holds the motor in the circuit long enough to
rotate the arms three revolutions and ensure that the screen is wiped
completely clean. (Figure 19 shows the wiring diagram used to
achieve this operation.)
The amount of clearance between the wiping brushes and the
filter screen is essential for efficient filtering action and long filter
screen wear. If the brushes are set too close to the screen, it is wiped
clean each cycle, but the screen will be worn through before the end
of one ginning season. By setting the brushes too far away from the
screen, a very thin layer of fly is left on the screen after each wiping
.cycle. The fly eventually becomes saturated with dust and almost
completely stops the flow of air through the screen. The pressure
switch is activated by the ensuing rise in pressure and energizes the
wiping motor circuit. Since, however, the brushes are not set close
enough to the filter screen to clean off the bat of dirt-saturated fly,
the pressure is not relieved, and the wiping motor circuit is contin-
uously energized. Moreover, the condenser exhaust air is diverted
into the 10-inch-diameter dust and fly pickup line. The resulting
rise in pressure caused by this additional volume of air is great
enough to cause a backlash at the gin stand. This would not happen,
however, to a Continental/Mbss-Gordin system. The pressure switches
in the gin and lint flue would cause the gin breast to be moved out
of ginning position before the pressure could become great enough
to cause a backlash. The wiping brushes must, therefore, be set close
enough to the screen to wipe it completely clean at the end of 'each
cycle, but not so close as to cause any unnecessary wearing of the
screen. Because this setting is so important, it should be done in the
74 COTTON-GINNING WASTES
-------
field after the complete erection of the filter and checked at regular
intervals to compensate for brush wear.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
T-B
SS-1 Mounted in master console, controls
power to circuit •
PS-1 Mounted inside gin building, wired
N.O., pressure rise in filter closes con- —
tacts «
T Mounted inside connection box
T-A Wired N.C., opens when timer is ener-
gized
T-B Wired N.O., closes when timer is ener-
gized, and holds motor in circuit
length of time desired
M Mounted on filter, %-hp, TEFC gear-
head motor
Figure 19 — Wiring diagram, Continental/Moss-Gordin, Inc., in-line filter.
MAINTENANCE AND OPERATING COSTS
Since the gin owner does not realize an actual cash return from
the in-line filter, minimum maintenance, low operating cost, and
quick repair or replacement are even more important than for most
gin machinery. For this reason the design of the Continental/Moss-
Gordin filter is functional, simple, and uncomplicated. The only items
that require any attention are the wiping motor, the drive chain, the
filter screen, and the wiping brushes.
The wiping motor is a Vs-hp gear motor, and the grease level
in the gearhead should be checked several times during the ginning
season to maintain it at the proper level. Because the motor is totally
enclosed fan cooled, it should require very little additional attention.
McLain
75
-------
If the filter is located outdoors, the drive chain should be kept well
lubricated during the ginning season and well protected from the
elements during the remainder of the year. These simple steps will
ensure long and trouble-free life for the motor and drive chain.
As pointed out before, the clearance between the filter screen
and the wiping brushes is very important and should be checked
several times during the ginning season. Because the wiping brushes
are made for much more severe service than they are subjected to
in the filter, they should last several seasons before they need to be
replaced. The only attention that the filter screen requires is replace-
ment when holes begin to wear in it. Because the life of the screen
depends upon several variables, and because the Continental/Moss-
Gordin filters have been in the field only two seasons, it is difficult to
say how often the screens will have to be replaced.
The cost of this maintenance per season is almost impossible to
calculate owing to the short time the units have been in the field,
though the cost of the items most likely to be replaced at one time
or another are available. The wiping brushes cost $3.86 per filter.
The 105- x 105-mesh screen costs $69.40 per filter, and the 40- x 40-
mesh screen costs $24.50 per filter.
Because very few man-hours are needed to operate the filters,
only the electrical power requirements of the filters have been
calculated in arriving at an operating cost. On the assumption that a
single filter cycles every 2 minutes and that the motor is energized
7.6 seconds each cycle, the motor will be energized a total of 45.6
minutes per 12-hour day. With a power cost of 3.3 cents per kilowatt-
hour, and a ginning rate of 6 bales per hour, the electrical power cost
for one filter located in the Mississippi Delta would be 0.0165 cent
per bale. In a gin that gins 3,000 bales per season, the total electrical
cost for the filters would be 0.495 cent. This example points out the
almost negligible operating cost of the filter.
The Continental/Moss-Gordin in-line filter was designed so that
the filter screen could be replaced quickly and easily if worn through
during the ginning season. If the wiping brush drive needs repair or
replacement during ginning operation, a large door is provided in the
housing that may be opened to allow passage of the exhaust air until
the drive can be put back into operating condition.
CONCLUSION
Since the gin owner does not realize an actual cash return on his
investment in the in-line filter, Continental/Moss-Gordin has at-
tempted to design and build a low-cost, highly efficient, trouble-free
filter. Only one size of housing is built to aid in mass production, but
two different mesh screens are used, depending upon the predominant
harvesting method in the area, to make the unit more versatile. Oper-
ation of the filter is simple, a minimum amount of maintenance is
required, operating costs are almost negligible, and on-the-job repair-
er replacement is quick and easy. At Continental/Moss-Gordin we
76 COTTON-GINNING WASTES
-------
feel that, with the aid of the research and design work done by the
USDA on the in-line filter, we have made available to the gin owner
another method of controlling air pollution effectively and econom-
ically.
REFERENCE
]Alberson, D. M., and Baker, R. V., An In-Line Air Filter for Collecting
Cotton Gin Condenser Air Pollutants, USDA, ARS 42-103 (Sept.) 1964.
Summary of Open Discussion
The speaker first explained that the in-line filter installation
mentioned in his talk was not experimental but represented one of
several installations that Continental/Moss-Gordin, Inc., has incor-
porated into practical dust control systems. The costs of the in-line
filter with totally enclosed fan-cooled gear motors is $890.00. With a
complete set of supports at $160 each, the total equipment cost is
$1,050.00.
McLain 77
-------
CONSIDERATIONS FOR DETERMINING
ACCEPTABLE AMBIENT AND SOURCE
CONCENTRATIONS FOR PARTICULATES
FROM COTTON GINS
Stanley T. Cuffe
and
James C. Knudson
National Center for Air Pollution Control
Public Heallth Service
U. S. Department of Health, Education, and Welfare
At the planning session for this symposium, participants from
state and local air pollution control agencies and the Department of
Agriculture were asked to provide information on (1) ambient air
quality and emission standards or objectives that have been adopted
in other areas and may have application to cotton-ginning operations.
(2) the bases upon which these standards were established, and
(3) exit loadings of trash and lint from ginning operations that would
be considered satisfactory for precluding nuisance complaints. The
information was, of course, limited to particulates since these are
responsible for most of the air pollution problems associated with the
operation of cotton gins.
AIR QUALITY STANDARDS OR OBJECTIVES
We should first point out that air quality standards or objectives
for suspended particulates have been established for entire geographic
areas such as states and counties but that they do not generally refer
to specific sources of emission such as a cotton gin or any other indus-
trial operation. Normally, the task of those setting emission standards
is to consider single emission sources in such a way that a desired air
quality goal can be achieved for the entire region. Even though par-
ticulates from cotton-ginning operations are related to air quality
goals in only their broadest aspects, a brief review of typical air
quality standards for suspended particulates is worthwhile. Similar
air quality objectives are likely to be established in some of the
cotton-growing regions, and control of emissions from cotton gins will
probably play an important role in ensuring that the air quality goals
of the region are met.
Typical definitions of air quality standards or objectives are those
of the States of New York and Colorado. The New York State Air
Pollution Control Board (1) sets as its ambient air quality objective
the level of air quality that will protect people from the adverse ef-
fects of air pollution and promote "maximum comfort and enjoyment
and use of property consistent with the economic and social well being
of the country." The Colorado Air Pollution Control Act(2) states:
Cuffe and Knudson 79
-------
"Standards of ambient air quality define the limits of air contamina-
tion by particulates and gases, above which limits, the ambient air
is hereby declared to be unacceptable and to require air pollution
control measures." These standards do not represent pollution con-
centrations at which there is a sharp demarcation between effect and
no effect, rather, the standards afford suitable assurance that no
adverse effects will occur.
Typical ambient air quality standards or objectives for particu-
lates in several state or metropolitan areas are shown in Table 12.
The California standards for gases and particulate matter include
three concentrations: Adverse, serious, and emergency. For par-
ticulate matter, only the adverse concentration is applicable. This is
the concentration at which there will be sensory irritation, damage to
vegetation, or reduction in visibility. The standard for particulate
matter is the concentration that is sufficient to reduce visibility to
less than 3 miles when relative humidity is less than YO percent. For
suspended particulates, the standard is a measurement of a physical
effect, that is, reduced visibility(3).
The Oregon State Sanitary Authority has set air quality stand-
ards for both suspended and settleable particulate matter and for a
chemical substance, lime dust. In residential and commercial land use
areas, the suspended particulate matter concentration is not to exceed
the normal background value by more than 150 micrograms per cubic
meter of air; the settleable particulate matter is not to exceed the
normal background value by more than 15 tons per square mile per
month. In heavy industrial land use areas, the suspended particulate
matter concentration is not to exceed the normal background value
by more than 250 micrograms per cubic meter of air; the settleable
particulate is not to exceed the normal background value by more
than 30 tons per square mile per month. For lime dust in particular,
maximum concentrations are not to exceed the normal background
values by more than 20 micrograms per cubic meter for suspended
particulates and by 1 ton per square mile per month for settleable
particulates (4).
The ambient air quality standards for Oregon are based upon
measurements made in various localities and particularly around
cement plants for suspended and settleable lime dust. These measure-
ments were correlated with the frequency of public complaints, and
the values chosen are those at which no significant dust nuisance
problem would be expected(5).
In the air resource management study in the greater St. Louis
area, ambient air concentrations of suspended particulates that have
been selected as goals to be achieved in the interstate area are (1) not
to exceed an annual geometric mean of 75 micrograms of suspended
particulates per cubic meter of air and (2) not to exceed 200 micro-
grams of suspended particulates per cubic meter of air during,more
than one 24-hour period in any 3-month period(6). In setting^ these
goals, consideration was given to the effects of suspended particulate
80 COTTON-GINNING WASTES
-------
matter in regard to visibility, soiling, corrosion, vegetation damage,
and health. In addition, consideration was given to the relationship
between measured participate concentrations in ambient air and
views expressed by citizens throughout the metropolitan area about
air quality, as determined in a public opinion survey. The goals
selected were those at which 90 percent of the people believed that
the concentrations of suspended particulates and settleable dust were
satisfactory and did not constitute an air pollution problem. Although
not shown in Table 12, a comparable air quality goal, that 200 micro-
grams of suspended particulates per cubic meter of air not be ex-
ceeded more than 1 day during any 3-month period, has been recom-
mended for the greater Nashville, Tennessee, area(7).
Up to this point, we have discussed air quality standards or ob-
jectives for particulates without regard to specific toxic possibilities.
Emissions from cotton gins could contain various pesticides and de-
foliants such as arsenic compounds, chlorinated hydrocarbons, or or-
ganophosphorus compounds. Threshold limit values for occupational
exposures are listed for many of these compounds, but these thresh-
TABLE 12 — SELECTED AMBIENT AIR QUALITY STANDARDS
OR OBJECTIVES FOR PARTICULATES
State
or area
California"
Particulate
category
Suspended
particulates
Unit of
measurement
Visibility in
miles
Standard
or goal
Sufficient to reduce vis-
ibility to less than 3
miles when the rela-
tive humidity is less
than 70 percent.
Oregon6 Nonspecific
particulates
Suspended /ig/m3 150C 250C
Settleable tons/mi2/month 15C 30C
Lime dust
Suspended /ig/m3 20C —
Settleable tons/mi2/month lc —
Metropolitan
St. Louis
Suspended
particulates
fig/m3
75 annual geometric
mean
200d annual 99th
percentile
aReference 3.
•"Reference 4.
cAbove normal background value.
dThe suspended particulate concentration must be less than 200 jug/m3 for
99 percent of the days in any 3-month period.
Cuffe and Knudson
81
-------
old values are based upon exposure of healthy workers 8 hours a day,
5 days a week, whereas ambient air quality standards must be based
upon exposure of the entire population, including the very young,
the very old, the sick, and the infirm, 24 hours a day, 7 days a week.
Unfortunately, there are no published air quality standards for these
compounds in the United States. The only published air quality
standards for certain toxic particulates are those of the Soviet Union.
The Soviet air quality standard for arsenic compounds is 0.003
milligram per cubic meter of air (24-hour-average value) (8). This
is considerably lower than the threshold limit value of 0.5 milligram
per cubic meter of air set by the American Conference of Govern-
mental Hygienists for the working environment. The industrial
hygiene value is based upon industrial exposure of workers in a
copper smelter. The bases for Soviet air quality standards according
to Stern(9) are clinical and epidemiological experience and experi-
mental studies on humans and animals. The Soviet scientists believe
that air quality standards should be set at concentrations below
those at which the most sensitive test shows any human response
whatsoever, regardless of whether the response is known to be detri-
mental or not.
Stern also mentions that 24-hour-average air quality standards
based upon consideration of harm to humans are often between one-
tenth and one-hundredth the occupational health threshold limit
value. Thus, a first approximation of the 24-hour-average air quality
standard for a substance for which no air quality standard has been
set is one-thirtieth the threshold limit value, unless evidence of
specific effects on people or property indicates the need for a different
standard.
EMISSION STANDARDS
An emission standard is a limit on the amount of pollutant that
may be emitted from a source and is intended to bring the ambient
air within acceptable air quality standards.
The first emission standards were adopted in the late 1880's to
prevent local nuisance from fly ash, smoke, and odors. Regulations
covering other pollutants were not adopted until 1947, in Los Angeles
County. Because of the severity of the air pollution problem there,
the various regulations on gaseous and particulate emissions were
approached from the aspect of technical feasibility. Thus, the concen-
trations of gaseous or particulate pollutants that would be discharged
from the most efficient commercially available control equipment
were generally selected as emission standards. Even in Los Angeles,
however, medium-efficiency collection equipment, for example, that
with 80 to 90 percent collection efficiency, was allowed for small
operations (10).
The most recent basis for setting emission standards f on urban
areas is the total air resource management concept(II). In essence,
82 COTTON-GINNING WASTES
-------
this involves measuring gaseous and particulate pollutants in the air
and making an emission inventory to determine the sources of the
various pollutants. With this information the percent by which spe-
cific gaseous and particulate pollutants must be reduced to achieve a
desired air quality goal can be calculated. The percent reduction
needed for a specific pollutant would be the basis for the emission
standard for that pollutant. Cost and technical feasibility must be
considered in arriving at the most advantageous reduction to apply
to each class of pollutant source.
This concept could be applied to cotton gins located in urban
areas. An emission limitation for particulates from cotton gins would,
however, vary for different communities, depending upon the amount
of suspended particulates emitted by cotton gins compared with those
emitted by other sources. An emission limitation that would reduce
suspended particulates would be expected to reduce also the nuisance
problem from settleable dust because these large particles should be
collected efficiently in the process that collects suspended particulates,
that is, particulates less than 20 to 40 microns in size.
The categories of pollutants that are limited by emission stand-
ards are shown in Table 13. The first category is total particulate
matter. This category normally includes particles larger than 30 to
40 microns as well as smaller particles. The larger particles usually
settle out near the source of emission, and though comparatively few
in number, they account for most of the particulate weight. Gravi-
metric emission standards are normally expressed as a weight of
particulates per volume or weight of stack gas. Commonly employed
units include grains per standard cubic foot (scf) or pounds per 1,000
pounds of dry flue gas corrected to 50 percent excess air. One grain
per scf is equal to approximately 1.9 pounds per 1,000 pounds of air.
The second category includes fine particulates, such as smoke, soot,
tars, and dust, that are usually less than 30 microns in size. Most fine
particulate matter remains suspended for a long time. The particles
with the greatest light-scattering properties are those ranging in
size from 0.3 to 0.7 micron. The visual emission standard is based
upon the percent of light transmitted through the exit plume and is
expressed as either a Ringelmann number or an equivalent opacity.
For the last category, bases or vapors, a volumetric emission standard
is normally used because the bases or vapors have comparatively little
weight and are usually invisible. The volumetric emission standard
is usually expressed as a volume of gaseous pollutant per volume of
stack gas, that is, parts per million (ppm).
I
PARTICULATE EMISSION ORDINANCES FOR INDUSTRIAL
PROCESSES
At present no emission ordinances or standards apply specifically
to cotton-ginning operations. Examples of particulate emission stand-
ards that have been adopted by various air pollution control agencies
to control particulates from industrial processes other than cotton
ginning are shown in Table 14. Two different approaches are shown
Cuffe and Knudson 83
-------
for limiting process particulate emissions: (1) The weight of particu-
lates per weight of stack gas, that is, pounds of particulates per 1,000
pounds of stack gas, and (2) allowable emissions based upon process
weight. For Pittsburgh and Detroit, the operating emission limitation
of 0.2 to 0.4 pound per 1,000 pounds of stack gas is less stringent than
the design limitation of 0.1 pound per 1,000 pounds of stack gas. This
recognizes that field operating conditions do not always meet design
conditions and that this could cause a temporary degradation in over-
all equipment performance.
TABLE 13 — CATEGORIES OF POLLUTANTS LIMITED BY
EMISSION STANDARDS
Type of emission
Pollutant category standards Typical units
Total particulate Gravimetric Ib particulate/1,000 Ib flue gasa
matter or grains/scfb
Fine particulate Visual appearance Ringelmann numberc
matter % equivalent opacity3
Gases or vapors Volumetric ppm by volume6
"For combustion processes, the grain loading is usually corrected to 50 per-
cent excess air.
bStandard conditions are usually 60°F and 14.7 pounds per square inch
absolute.
cThe Ringelmann Chart grades black or grey smoke into five shade cate-
gories, giving a Ringelmann No. 0 to a clean stack, and a No. 5 to a com-
pletely opaque plume.
Equivalent opacity—of such opacity as to obscure the observers' view to
the same degree as a smoke plume of the same Ringelmann number.
eVolumes of pollutant per million volumes of gas.
The regulation of allowable emissions based upon process weight
was started in Los Angeles in 1949(12). The approach has since been
used by several other cities(13). Allowable emissions are given in
pounds per hour and range from about 0.5 per hour for a process
weight of 100 pounds per hour to 40 pounds per hour for a process
weight of 60,000 pounds per hour. In terms of particulate collection
efficiencies, the Los Angeles County regulation requires from 85 per-
cent for small sources to over 99 percent for large industrial processes.
Grain loadings in stack gas from large plants must be less than 0.05
grain per scf, whereas dust loadings as great as 0.1 to 0.2 grain per scf
of stack gas from small plants may be permitted if they do not violate
the visible emission limitation of a No. 2 Ringlemann number or the
equivalent opacity. In deriving the process weight emission limits, the
Los Angeles County Air Pollution Control District conducted a number
of stack emission tests at plants processing steel, grey iron, and non-
ferrous metal to determine the capabilities of particulate control
systems.
84 COTTON-GINNING WASTES
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TABLE 14 — PARTICULATE EMISSION ORDINANCES FOR
INDUSTRIAL PROCESSES(13)
Air pollution Particulate emission
control agency limits
Allegheny County, Pennsylvania 0.5 lb/1,000 Ib flue gas; for blast
(Includes City of Pittsburgh) furnaces
0.2 lb/1,000 Ib flue gas; for basic
oxygen furnaces
Detroit, Michigan 0.10 lb/1,000 Ib flue gas; for
design8
0.2 to 0.4 lb/1,000 Ib flue gas;
for operation11
Los Angeles County, Dade Allowable emission rates vary
County (Miami), New York City, with the process weight
San Francisco Bay Area, and
Beloit, Wis.
"Design emission standards for ferrous cupolas and steel furnaces.
bOperating emission standards for ferrous cupolas and steel furnaces.
The New York State Air Pollution Control Board recommends
air contaminant emission guides based upon potential emission rates
from uncontrolled sources (14). The guides include recommended col-
lection efficiencies for various classes of particulate and gaseous pol-
lutants based upon toxicity. For Class A, the most toxic class, which
includes beryllium and nickel carbonyl, collection efficiencies of at
least 99 percent are required. For Class B, which includes particu-
lates containing materials such as arsenic and lead, 95 to 98 percent
removal is required for potential emission rates up to 20 pounds per
hour, and 98 percent, for rates above 20 pounds per hour. Class C
requires a 90 to 95 percent collection efficiency for potential emission
rates of 20 to 4,000 pounds per hour for compounds such as phosphoric
and sulfuric acid. For relatively nontoxic materials (Classes D, E,
and F) collection efficiencies of 80 to 95 percent are recommended for
potential emission rates ranging from 20 to 4,000 pounds per hour.
The recommended collection efficiencies in the New York State
Air Contaminant Guides for controlling specific source emissions are
based mainly upon technical and economic feasibility. Although no
correlation was made between emission concentrations and ambient
ground level concentrations for specific pollutants, consideration was
given to the size of the source and the relative potential effect of the
air contaminant on humans, animals, vegetation, and property. Thus,
the larger the source and the greater the relative effect of the con-
taminant, the more stringent the guide(15).
The New Jersey Air Pollution Control Commission has estab-
lished emission standards for the control of both coarse and fine
Cuffe and Knudson 85
-------
participates(26). In setting the standards, the Commission considered
both stack height and distance from the stack to the nearest property
line. Thus, higher emission rates are allowed for higher stacks and
for greater distances from the stack to the nearest plant property line.
Allowable emission rates for coarse particulates (larger than 44
microns) range from 0.5 pound per hour for a stack 20 feet high
and 20 feet from the nearest property line to 1,000 pounds per hour
for a stack 500 feet high and 7,500 feet from the nearest property
line. For fine particulates, allowable emission rates, from comparable
stack heights and distances to property lines, range from 1.8 to
1,125 pounds per hour.
The New Jersey regulation is designed to control emissions of
coarse particulates so that no one stack will contribute more than
200 tons per square mile per year to the total dustfall off the prem-
ises of the emitter. This standard is based upon measured dustfall
amounts in New Jersey and other places believed to be acceptably
clean.
In establishing the relationship between the concentration of fine
particulates (suspended) in the air and the allowable emission rate
from the stack, the New Jersey Commission used the diffusion
formula of Bosanquet. The maximum allowable concentration for
suspended particulates is 615 micrograms per cubic meter of air. The
long-time concentration at a point 10 stack heights downwind from
the source is estimated to be 25 micrograms per cubic meter of air.
CONSIDERATIONS FOR PARTICULATE EMISSION LIMITA-
TIONS FOR COTTON GINS
As a first step in considering emission limitations for cotton gins
that would be effective in precluding nuisance complaints and unde-
sirable health effects, we should look at existing emission and air
quality data for particulates from cotton gins. In the progress report
of an air pollution study of cotton gins in Texas (17), as reported by
Mr. Otto Paganini earlier in the symposium, concentrations of
suspended particulates (see Table 15) were noted at various distances
downwind from operating gins. The concentrations of suspended
particulates at distances of 150 to 300 feet from the gins were ex-
tremely large, the largest being at a distance of 300 feet. The much
smaller concentrations of suspended particulates at distances beyond
1,200 feet would indicate that a good portion of the particulates meas-
ured within 300 feet of the gin are settleable and are larger than 40
microns in size. The concentrations of suspended particulates within
2,000 feet of the gins would not meet the air quality standards for
Colorado or those for the metropolitan areas of St. Louis or Nashville.
The degree of control of emissions of trash and lint from the gins
tested was not detailed in the report; however, from the large par-
ticulate concentrations reported within 300 feet, it would appear that
most of the gins operated with very low-efficiency emission control
systems.
86 COTTON-GINNING WASTES
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TABLE 15 — SUSPENDED PARTICULATE AND ARSENIC
CONCENTRATIONS IN THE AIR NEAR COTTON GINS IN
WEST TEX AS (17)
Distance Range of suspended
from gin, particulate concentrations,"
ft jtg/m3
150 to 300
1,200 to 1,400
2,200 to 8,000
5,000 to 76,000
385 to 187
217 to 42
Range of arsenic
concentrations,6
^g/m-3
0.6 to 141
0.07 to 0.08
0.10 to 0.01
"Sampling times ranged from 1 to 8 hours.
bAnalyzed by the pyridine-silver diethyldithiocarbamate method.
The concentrations of arsenic in the particulates were also cor-
respondingly large within 300 feet of several gins. An arsenic loading
of 141 micrograms per cubic meter is appreciably greater than the
Russian air quality standard for arsenic, that is, 3 micrograms per
cubic meter. The arsenic concentrations beyond 1,000 feet were,
however, considerably less than the Russian standard. For healthy
workers exposed 8 hours a day, 5 days a week in the immediate area,
the maximum allowable concentration for arsenic compounds recom-
mended by the American Conference of Governmental Industrial
Hygienists is 500 micrograms per cubic meter, which is considerably
greater than the measured concentrations.
As in the case of ambient air measurements, very little published
data are available on particulate emissions from cotton gins. In the
Public Health Service report entitled, Airborne Particulate Emissions
From Cotton-Ginning Operations(18), particulate grain loadings were
measured at each point of emission from the experimental cotton gin
at the Agricultural Research Service Cotton-Ginning Laboratory at
Stoneville, Mississippi. Particulates were collected in a 2-stage
sampling train by isokinetic sampling procedures. The first stage
consisted of a settling chamber that removed particles larger than
100 microns. In the second stage, the remainder of the particulates
(those smaller than 100 microns) were collected on a fiberglass filter.
Total particulate emissions from the unloading fan, the six-cylinder
cleaner, and the stick and bur machine ranged from 0.12 to 0.55 grain
per scf (Table 16). These loadings are relatively large, and particu-
late fallout would be expected to cause a nuisance. The particulate
grain loadings from the six-cylinder cleaner and the stick and bur
machine for particles less than 100 microns in size were relatively
small; they ranged from 0.3 to 0.04 grain per scf. These loadings of
fine particulate matter are within the emission limitations set by air
pollution control agencies. Emission limitations could, therefore, be
achieved by removing the particles larger than 100 microns in high-
efficiency cyclone collectors. Where cyclone collectors were used on
the seven-cylinder cleaner, the exit grain loading from the 84-inch-
diameter standard cyclone was 0.01 grain per scf, and the loading
Cuffe and Knudson 87
-------
from the 34-inch-diameter high-efficiency cyclone was only 0.005
grain per scf. These are very small grain loadings for particulate
emissions from any type of source, that is, they are the exit particulate
concentrations one would expect from a high-efficiency (99 percent)
electrostatic precipitator or a fabric filter baghouse serving a Port-
land cement plant, a grey iron cupola, or a grain-processing plant.
Dust fallout nuisance would not be expected from these small par-
ticulate emissions. Likewise, if emissions of trash and lint from oper-
ating commercial cotton gins equipped with centrifugal collectors
were at the same small concentrations, one would not ordinarily
expect a significant air pollution problem. Particulate emissions from
many operating cotton gins, both with and without mechanical col-
lectors are said, however, to cause lint and trash fallout problems.
Apparently, therefore, the definition of emission and ambient air
concentrations of suspended and settleable particulates from both
cotton gins and trash incinerators should be more detailed.
TABLE 16 — PARTICULATE EMISSIONS FROM
STONEVILLE COTTON GIN (18)
Sampling
point
Unloading fan
Six-cylinder
cleaner
Stick and bur
machine
Settling
chamber,
gr/scf
—
0.08
0.52
Sampling
filter,
gr/scf
0.36
0.04
0.03
Total
gr/scf
0.36
0.12
0.55
Seven-cylinder
cleaner a 0.01 0.01
b 0.005 0.005
Condenser — 0.02 0.02
"Standard cyclone—84-inch diameter.
bHigh-efficiency cyclone—34-inch diameter.
RECOMMENDED FIELD TESTING PROGRAM
A field testing program that would provide this information
should include several elements. The various types of commercially
available emission control systems for cotton trash and lint should
be tested on operating cotton gins in different sections of the country
and on experimental gins at Agricultural Research Service Labora-
tories. The system should be tested at varying loads while processing
cotton harvested by hand or by machine picking, stripping, or scrap-
ing. Particulate samples should be collected simultaneously before
and after trash and lint collectors to determine efficiencies of and
exit grain loadings from the latter collectors. A sample train for
collecting the trash or lint samples would include: (1) A; settling
88 COTTON-GINNING WASTES
-------
chamber for collecting settleable particulates, that is, particles larger
than 40 microns; (2) a high-efficiency cyclone for collecting particles
3 to 40 microns in size, and (3) a fiberglass filter for collecting the
remaining fine particulates below 3 microns in size. Collection of
particulates smaller than 3 microns would include the portion that
could reach the lower section of the respiratory tract.
The basic design parameters or operating procedures, or both,
for various types of trash and lint emission control systems should
also be investigated to determine their effect on particulate emissions.
Concentrations of particulates in the ambient air should be deter-
mined at various distances downwind from cotton gins and from trash
incinerators. The measured particulate levels would provide useful
information for determining the distances from controlled and un-
controlled cotton gins and trash incinerators beyond which dust and
fly ash fallout would not be expected to be a problem. For relatively
isolated gins in rural areas, the same degree of control for dust and
lint may not be needed as would be the case for gins located in or
near urban areas. This approach has been used for isolated portable,
asphalt batch plants in Florida. For rural plants with a buffer zone
of 1 mile's radius or more between the plant and any population,
lower efficiency dust control equipment is required than for plants
located in populated areas(19).
Particulate samples should also be analyzed for pesticides and
defoliants known to be used in the area. If the concentrations found
are believed to be significant from the standpoint of effects on health,
epidemiological studies should be initiated in that area.
Since the control of emissions from cotton-ginning operations is
more of an economic problem than one of technical feasibility, infor-
mation should also be secured on the installation and operation cost
of efficient particulate control systems for use on both large and small
cotton gins.
This type of information on performance and costs of particulate
control systems and measurements of source and ambient air concen-
trations of particulates, pesticides, and defoliants would then provide
the baseline data needed for setting effective source emission or
ambient air standards for cotton-ginning operations.
REFERENCES
1. U. S. Department of Health, Education, and Welfare, A Compilation
of Ambient Air Quality Standards and Objectives. Prepared by the
Technical Assistance Branch, DAP, USPHS, Cincinnati, Ohio, May 11,
1965, p. 1.
2. Ibid, p. 16.
3. Ibid, p. 13.
4. Ibid, p. 17.
Cuffe and Knudson 89
-------
5. Patterson, H. M., Oregon State Sanitary Authority State Board of
Health. Private communication.
6. Technical Assistance Branch, Division of Air Pollution, U. S. Public
Health Service, Cincinnati, Ohio. Unpublished data.
7. Williams, J. D., and Edmisten, N. G., An Air Resource Management
Plan for the Nashville Metropolitan Area, U. S. Public Health Service
Pub. No. 999-AP-18, Cincinnati, Ohio, 1965.
8. Stern, A. C., Summary of Existing Air Pollution Standards, JAPCA,
14:5-15 (Jan.) 1964.
9. Stern, A. C., Air Pollution, Vol. II, 1st ed., p. 490. Academic Press,
New York, 1962.
10. McCabe, L. C., Rose, A. H., Hamming, W. J., and Viets, F. H., Dust and
Fume Standards, Indus, and Eng. Chem. 41:2388, (Nov.) 1949.
11. Williams, J. D., and Schueneman, J. J., Air Resource Management
Planning as a Part of Comprehensive Urban Planning Programs. U. S.
Public Health Service, Cincinnati, Ohio (May) 1963.
12. McCabe, L. C., loc. cit., p. 2389.
13. U. S. Department of Health, Education, and Welfare, A Compilation
of Selected Air Pollution Emission Control Regulations and Ordinances,
U. S. Public Health Service, Report A65-34, Cincinnati, Ohio, May 11,
1965.
14. New York State Air Pollution Control Board, Council of Technical
Advisors, Current Guides for Prevention of New Air Pollution, Albany,
New York (June) 1962.
15. Marlow, S., Division of Industrial Hygiene, Department of Labor, State
of New York. Private communication.
16. Winkelman, L. A., Emission Standards for the Control of Solid Particles,
A New Approach by New Jersey, JAPCA. 14:441-445 (Nov.) 1964.
17. Paganini, O., Air Pollution Study of Cotton Gins in Texas. Texas State
Department of Health, Austin, Texas, April 15, 1965.
18. U. S. Department of Health, Education, and Welfare, Airborne Particu-
late Emissions from Cotton-Ginning Operations. U. S. Public Health
Service, Report A60-5, Cincinnati, Ohio, 1960.
19. Florida State Board of Health, Buffer Zone Study for Portable Asphalt
Plants, Bureau of Sanitary Engineering, Jacksonville, Florida.
Summary of Open Discussion
In regard to the 1-mile radius buffer zone for portable asphalt
plants in Florida, no population would be allowed within this area.
A cyclone collector is still required for portable asphalt plants within
the buffer zone, whereas in or near an urban area, both a cyclone
collector and a water scrubber are required.
90 COTTON-GINNING WASTES
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RECOMMENDATIONS FOR NEEDED
RESEARCH AND DEVELOPMENT
Ralph C. Graber
National Center for Air Pollution Control
Public Health Service
U. S. Department of Health, Education, and Welfare
Before I outline the areas of needed research in the control and
disposal of cotton-ginning wastes, I think it is important to identify
the broad objectives to which our efforts should be directed. These
objectives are: (1) To develop efficient, less costly systems and tech-
niques for the control and disposal of cotton-ginning wastes; (2) to
provide reliable information on emission sources and ambient air
concentrations of emissions from cotton gins and trash incineration;
and (3) to provide more specific information on possible effects of
atmospheric emissions from cotton-ginning operations on health.
As previous speakers have reported, the primary emissions of air
pollutants are trash, dust, and lint from cotton gins, and fly ash and
smoke from incineration of cotton trash. A field testing program
should, therefore, be undertaken to determine the concentrations and
amounts of suspended and settleable particulate from both cotton
ginning and trash incineration. Information on particle size distribu-
tion is needed for estimating the fraction of dust that settles near the
gin or remains suspended, and, more importantly, the portion of
particulate smaller than 3 to 5 microns that could reach the lower
section of the human respiratory tract. Source sampling for concen-
trations of particulate before and after dust and lint control systems
would provide needed information on collection efficiencies and exit
grain loadings for particulates. Basic control equipment, such as the
in-line filter and high- and low-efficiency cyclones, and secondary
collection devices such as the wet cyclone and the wiped wire screen
mentioned by previous speakers should be tested further. Although
some of this information could be obtained from studies conducted
in the Agricultural Research Service laboratories, much of the field
testing should be conducted at operating commercial gins in various
sections of the country.
As an extension of the work conducted by the Texas State De-
partment of Health, ambient air concentrations for suspended and
settleable particulate should be determined at various distances down-
wind from cotton gins and from trash incineration. This information
would be of interest in determining the distances from a controlled
or uncontrolled cotton gin that dust nuisance problems would not be
expected to occur. Particulate samples collected from both ambient
air and source sampling at or near cotton gins should also be analyzed
for concentrations of pesticides, defoliants, and desiccants that are
known to be used in the immediate area—to determine whether the
concentrations of these toxic substances are significant from the
standpoint of effects on health.
Graber 91
-------
Another area of needed research is the disposal of cotton trash.
There is no general agreement that incineration is a satisfactory
method of trash disposal from an air pollution standpoint. It is hoped,
therefore, that composting studies, such as those conducted by Mr.
O'Neal, will be continued and new techniques developed.
Since the degree of source control should be related to the en-
vironmental effects of these particulates, epidemiological studies
should be conducted in the immediate vicinity of cotton gins. Addi-
tional and more specific information is needed on the effects of cotton-
ginning dust on health when the dust contains pesticides, defoliants,
bacteria, and other microorganisms that may contribute to irritation
and disease in the human respiratory system.
Another area of recommended research relates to a more or less
preventive approach to air pollution control. I refer to a need for addi-
tional development work on picking machines that would harvest
cleaner cotton and thereby reduce the equipment needed.
The last area of recommended research, which is as important
as any, is the development of low-cost, effective dust and lint collec-
tion and disposal systems. The Department of Agriculture's research
laboratories have done a fine job in developing relatively low-cost
lint collection equipment. Because of the economics of this seasonal
industry, however, there is a need, particularly for smaller gins, for
dust and lint control concepts and innovations that are less costly to
install, operate, and maintain. It is hoped that the Agricultural Re-
search Service laboratories will continue work along this line of
research. It is assumed, too, that the manufacturers of control equip-
ment will step up their efforts to develop the needed hardware.
In summary, I suggest that these areas of research and further
investigation be conducted by the Public Health Service, the Depart-
ment of Agriculture, universities, and interested health agencies and
cotton-ginning associations. In order to accomplish the outlined re-
search most effectively, cooperation and participation by these several
organizations will be needed.
92 COTTON-GINNING WASTES
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PANEL DISCUSSION
V. L. Stedronsky
Andrew O'Neal
Otto Paganini
Edward H. Bush
Stanley T. Cuffe
Mr. Taylor: Can ambient air quality standards be the basis for
effective enforcement?
Mr. Cuffe: Ambient air quality standards have been established
and are used for a county, city, or even a state. Trying to enforce
these standards or goals for one particular source would be difficult if
the source were located in an urban area. Applying an emission
limitation, such as a maximum pounds per hour of allowable par-
ticulate emission, or visual limitations such as the Ringelmann num-
ber or equivalent opacity, is preferable for enforcement purposes.
Mr. Herzik: I think that somewhat similar problems exist in the
field of water pollution control since I know, being active in that field
as well as air pollution control, that the question frequently arises.
I am sure they know the answer when they ask: "What are you going
to do about meeting standards for water pollution control when the
body of water about which you are talking already exceeds the
standards that you have established?" I think this might apply in
this case; it would be a very specialized one that would probably
have to be considered on the merits of the case alone.
Mr. Bath: In dealing with emission and air quality standards for
participates, the situation might arise whereby any one basis, that is,
weight, volume, and so forth may not prove effective in dealing with
the problem. Would you then find new standards or criteria or simply
make the old standards more rigid?
Mr. Cuffe: Emission standards are usually applied to general
particulates and specific gases. It would be that portion of dust of
less than 3 to 4 microns that can be a problem in the respiratory tract.
If it were shown that this was the case, then there would have to be
a special limitation for that specific dust, but I am not familiar with
cases where that has been actually applied. I should add that the
Public Health Service is establishing air quality criteria. In the past
year and a half they have gathered a great deal of published informa-
tion on the effects of sulfur dioxide on humans, plants, animals, and
other substances. I cannot say exactly when, but I should expect
that within the next 6 months the Public Health Service will issue
air quality criteria for sulfur dioxide. This will be followed by
criteria for oxidants. Particulates are a very difficult category and I
suspect it will be several years before the Public Health Service
issues air quality criteria for this category.
Mr. Paganini: If I may interject here on these analyses that we
made, we listed total suspended particulate matter, and usually, sus-
Stedronsky, O'Neal, Paganini, Bush, and Cuffe 93
-------
pended particulate matter consists of particles of a size of 100 microns
or less. You will probably have a certain percentage, depending upon
the process of emission, that may range from submicron up to 100
microns in size; this is something that can be taken into account in
these ambient air standards as far as suspended particulate matter is
concerned.
Question: It takes a lot of money to control gin dust. I wonder
if it is possible to set up three or four demonstration units to show
people how to control cotton-ginning effluents?
Mr. Cuffe: Well, I think what the Public Health Service would
prefer before model gins are set up is to conduct source tests to deter-
mine the most effective design parameters and operating procedures
for various types of particulate control systems for cotton gins. The
results could be published in a report and made available to all
interested parties.
Comment: The ginner has to spend $25,000 fixing up a cotton
gin and has no way of measuring whether it is effective or not.
Mr. Cuffe: I think Mr. Graber covered this in some recommenda-
tions for needed research. It may be of interest to know, however,
what the Public Health Service has done these past several years with
other industries. We have a cooperative study agreement with the
Manufacturing Chemists' Association and have made comprehensive
studies of emissions from sulfuric acid- and nitric acid-manufacturing
processes. We determined the types and concentrations of various
gaseous and particulate pollutants, collection efficiencies of abatement
equipment normally employed, and the effects of various process
operating conditions on emissions. I should expect that this type of
study could be done cooperatively with the Public Health Service,
Department of Agriculture, and other interested state or local agencies
and cotton-ginning associations.
Mr. Moore: One substance we have discussed is arsenic. Would
arsenic standards that you are speaking of be uniform for the United
States, that is, hotel rooms in Dallas, Texas, or New York City as
opposed to a gin system here in Texas?
Mr. Cuffe: If and when there are air quality standards for ar-
senic, I should expect that the Public Health Service would recom-
mend their use nationally. Again there may be others adopted by
states themselves. There are presently only threshold limit values
published by the American Conference of Governmental Industrial
Hygienists for working atmospheres for 8 hours a day, 5 days a week,
for healthy adults. Air quality standards would apply to people 24
hours a day, 7 days a week, and include, in addition to healthy adults,
the young, the old, and the sick. Values that were chosen may be
lower than the threshold limit values by a factor one-tenth to one-
hundredth that value.
Question: Has any thought been given to financial assistance to
aid the gin owner in purchasing control equipment? Has i considera-
tion been given at the state or local level or any level? j
94 COTTON-GINNING WASTES
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Mr. Cuffe: From what has been said here by Mr. Bush and others,
apparently many gins, particularly those ginning less than 1,700 bales
per day, do have an economic problem. One thing that could be done
is to exempt air pollution control equipment from taxes at either
the state or local level. There are two states, California and, I be-
lieve, Wisconsin, that allow an accelerated amortization on this
equipment of 5 years.
Mr. Bush: I should like to speak on this subject. I am thinking
of a parallel to the recent highway beautification program where, I
believe, $2,500 per junk yard is provided for screens. This is a sub-
sidy paid to the owner either directly or through the highway depart-
ment of the various states for screening off his property. To me and
to some of us in the industry, this is a rather similar type of parallel.
Here we are being called upon to enter into something overnight,
so to speak, that may or may not in every instance be because of a
health hazard or nuisance. It is conceivable that this same type of
thinking can be applied to air pollution.
Mr. Cuffe: Mr. Hickman, would you care to make a few com-
ments about the operations of the Federal solid-waste program?
Mr. Hickman: I represent the Office of Solid Wastes* of the U. S.
Public Health Service. We have been in existence as a Federal agency
since the first of the year. I should like to make a few comments and
shall be glad to answer questions afterwards.
In his State of the Union message to the Congress in January
1965, President Johnson proposed to increase the beauty of America
and end the poisoning of our rivers and of the air we breathe. In
October 1965, he made good his proposal by signing the Clean Air Act
Amendments and the Solid-Waste Disposal Act.
The Surgeon General of the Public Health Service, Dr. William
H. Stewart, publicly committed our agency to this new field of en-
vironmental control when he established the Office of Solid Wastes
in January 1966. He said that "in establishing the Office of Solid
Wastes, we are taking another step in our fight against environmental
pollution. We are reinforcing our efforts to stem the tide of air, water,
and land pollution, to restore the beauty of our land, and to protect
the millions of our citizens affected by these man-made threats to
health and well being."
Solid wastes include a vast variety of salvageable, nonsalvage-
able, convertible and nonconvertible materials discarded every day
by us as individuals, by industry, by commercial and agricultural
operations, and by urban living. These include garbage, rubbish,
ashes, street refuse, demolition and construction debris, abandoned
automobiles, old refrigerators, furniture, dead animals, and the wastes
from slaughter houses, canneries, manufacturing and processing
plants, farms, and hospitals.
*Now part of the National Center for Urban and Industrial Health.
Stedronsky, O'Neal, Paganini, Bush, and Cuffe 95
-------
Current national production of solid wastes amounts to almost
900 million pounds daily or about 4V2 pounds per person. It is esti-
mated that the total will be 3 times that amount by 1980. What are
we going to do with all this solid waste our high-class society is
generating?
When the Gemini Astronauts returned from their 8-day mission
in 1965, they singled out "stowage" as the principal problem aloft.
Where did they put all the garbage, what to do with it? The question
of what to do with trash has worried engineers ever since the design
of spacecraft became a matter of practical concern. To the engineer-
ing purist, the answer lies in a "closed ecological system," in which
everything is endlessly reused and never wasted or lost. A system
of this sort, engineers feel, exists right here on earth. In fact, the
planet earth itself is an efficient closed ecological system, or so it has
generally seemed.
Restoring the Quality of Our Environment, a report issued last
November by the Environmental Pollution Panel of the President's
Science Advisory Committee, summarizes thoughts on the subject
that have been circulated for a number of years. Perhaps, the report
suggests, our terrestrial spaceship with its 3 billion passengers is not
really operating as a closed ecological system at all, for in the onrush
of civilization, man is wasting, ruining, corrupting, poisoning, and
breaking things faster than nature can regenerate them and put them
back into the supply line. The Panel's report includes 22 recommen-
dations specifically on solid waste.
Enacted in October 1965, the Solid-Waste Disposal Act, like the
Clean Air Act, the Water Pollution Act, and other legislation in the
area of environmental pollution control, recognizes that the primary
responsibility for dealing with these problems rests with state, local,
and regional agencies. Nevertheless, these levels of government also
look to the Federal Government for guidance and aid. The Solid-
Waste Disposal Act is intended to enable the Federal Government to
help create a coordinated national solid-waste disposal program by
bolstering the efforts of the state and local governments.
The Act authorizes a broad basic program of the Federal Gov-
ernment—research, training, technical services, and grant support for
demonstrations and planning of local and state programs. The re-
search needed is chiefly to devise and perfect methods that effectively
collect, treat, and dispose of solid wastes while avoiding environ-
mental contamination, and hopefully, permitting the recovery of the
vast amounts of salvageable materials now being lost through prim-
itive disposal practices.
Balancing the research and training efforts that the Federal Gov-
ernment will be making, the Solid-Wastes Disposal Act provides a
method of stimulating state and local agencies to develop and operate
more sanitary, efficient, and economical waste programs. The Secre-
tary of HEW is authorized to provide financial and technical assistance
to public agencies—and to institutions and individuals /engaged in
COTTON-GINNING WASTES
-------
research—to promote research, demonstrations, surveys, and training
concerned with the operation of solid-waste disposal programs.
We are also authorized to make grants to state and interstate
agencies on a matching fund basis for the development of local
programs.
To carry out these new activities, the Solid-Waste Disposal Act
authorizes the appropriation of over 92 million dollars in the next 4
fiscal years. For the last half of Fiscal Year 1966 we received 4 mil-
lion dollars. We should receive approximately 13 million or maybe
14 million dollars in Fiscal Year 1967.
The Solid-Waste Disposal Act gives the cities, states, and Federal
Government an unparalleled opportunity to reverse the relentless
trend of the discard of abundance, the erosion of the natural beauty of
this country, and the health hazards created by improper solid-waste
disposal practices.
Mr. Cuffe: Mr. Hickman, would you classify cotton trash as an
agricultural solid waste?
Mr. Hickman: Yes, it was so defined by the Congress in the Solid-
Waste Disposal Act when they defined solid wastes as garbage, refuse,
and other discarded solid materials including solid waste material
resulting from industrial, commercial, and agricultural operations.
Mr. Cuffe: In addition to state or local government agencies, can
nonprofit organizations qualify for a grant?
Mr. Hickman: Any nonprofit organization is eligible for a grant
for demonstration of a new or improved technique of solid-waste
disposal.
Mr. Paganini: Would that be an outright grant or would it have
to be a matching grant?
Mr. Hickman: Well, demonstration grants have to be 2 to 1;
we match two-thirds against one-third.
Comment: Under the current practices we have today, the disposal
of agricultural wastes is about the same as that of municipal or other
types. Composting is one method; incineration and landfill are other
methods of disposing of agricultural wastes. Here again, we can fore-
see many areas that will need research and study to develop practices
and methods of disposing of agricultural solid wastes. One thing
about cotton-ginning wastes that has merit, compared with others, is
that they are almost entirely organic and have value for plant food
and other uses, whereas urban solid waste is going from the organic
to the inorganic, very markedly, and this is creating an additional
disposal problem.
Mr. Herzik: Mr. Hickman, for the benefit of the health depart-
ment people and other enforcing agencies here, on your fund program,
this matching 2-to-l ratio is for different situations. Is this as it was
Stedronsky, O'Neal, Paganini, Bush, and Cuffe 97
-------
in the air pollution program? Must the money matched be new
money?
Mr. Hickman: It does not have to be new money; it cannot be
Federal grant money allotted for anything else.
Mr. Herzik: If the state, in our case for example, already has
two people paid by the state on solid-waste disposal activities, could
this be used for matching purposes?
Mr. Hickman: This could be brought in under the planning grant,
yes.
Mr. Paganini: Mr. Hickman, in expanding on Mr. Herzik's ques-
tion, could this include nonprofit organizations that now have people
working and could they assign their salaries and any other equipment
or so forth for this? Could it be applied that way?
Mr. Hickman: I am not sure about existing equipment. Any new
equipment they would have to purchase could, of course, be con-
sidered under the grant. If they are assigning people from another
activity to a solid-waste disposal activity, there is no reason why
their salaries cannot be counted toward part of the matching fund.
Of course, all applications are on a competitive basis. They submit
theirs, and then they take their chances like any other organization.
Mr. Paganini: Mr. Hickman, before you get away, in regard to
this, is there a percentage allocation to each state? And if so, are
you competing with all other municipalities in that state on that per-
centage basis?
Mr. Hickman: No state can receive more than 12.5 percent of
the total grant funds appropriated under any one section of the Act.
Mr. Cuffe: Mr. Hickman, if there were individuals or organizations
here today interested in filling out forms, who could give them
assistance?
Mr. Hickman: Well, of course, we shall staff our regional offices,
that is, the Public Health Service Regional Office, just like our other
environmental health programs do. Presently, though, we have only
three regional program directors. The rest of the regional offices, such
as the Dallas Office, are being handled by our Division of Environ-
mental Engineering and Food Protection.* They have the material
and can provide forms and assistance in their preparation.
Mr. Paganini: In regard to the report that will be coming out on
the study we did around cotton gins; when it is completed it will be-
come available. If you wish to obtain a copy, write us a letter for
our files and we shall send the report out to you when it is made
available.
In behalf of the representatives of manufacturing companies who
may be present, I should like to ask Mr. Stedronsky to give us a list
"Now part of the National Center for Urban and Industrial Health.
98 COTTON-GINNING WASTES
-------
of all the manufacturers of in-line niters or other air pollution control
equipment.
Mr. Stedronsky: I don't know whether I can give you the names
of all the firms that make that type of equipment. We have plenty of
material on file at the office, but I don't have any with me now. As
far as in-line filters are concerned, every few days I hear of someone
else who is making them, and as of now, these are the names
that I have picked up. If I overlook anyone, it is certainly uninten-
tional. At present it is my understanding that, of the gin machinery
manufacturers, the Continental/Moss-Gordin and Lummus Cotton
Gin Company are making in-line niters. I believe I heard somewhere
that the Murray Company is interested; if Hardwick-Etter is making
any, I haven't heard of it. Those are the major machinery manu-
facturers of the full line of ginning equipment. The other folks, I
have heard, are the Anderson-Bigham Sheet Metal Works; the Metal
Products Company, also of Lubbock; the Bruton Manufacturing Com-
pany at Lamesa, Texas; the El Paso Sheet Metal Works of El Paso;
and Wonderstate Manufacturing Co. of Paragould, Arkansas. Those
are all the people I have heard of. I don't know whether Mission
Sheet Metal or Mission Engineering have made any or not.
Mr. O'Neal: Well, I have been thinking a little bit about private
business. This was all government we have been talking about, I
believe. I think many good ideas for improving on dust-collecting
equipment may simply be sat on instead of patented, unless there is
some method, for the people who are going to push this program, of
either making recommendations, or helping to test, or even buying
the patents for public consumption. I have wondered something
about that. Is there any comment that Mr. Cuffe or anybody can make
on that?
Mr. Cuffe: Andy (O'Neal), were you referring to the availability
of funds from the Solid-Waste Disposal Act?
Mr. O'Neal: I certainly would not have any idea where the funds
would come from. I just wondered whether any thought was given to
the funds at all.
Mr. Cuffe: Not to my knowledge. That is why I specifically asked
Mr. Hickman whether only nonprofit organizations can qualify for
Solid-Waste funds. As far as providing money for it, do you have an
improved or new process for composting?
I
Mr. O'Neal: I know some good ideas for handling materials—
taking care of fines or sacking them; if the people who have patents
are generally pretty proud of them and just don't give them away,
as I did this one up here, they are going to sit on them.
Mr. Cuffe: You have a worthwhile point there. It would be nice
to have some encouragement from private initiative, particularly
from those with limited resources. Offhand I don't know what it
would be.
Stedronsky, O'Neal. Paganini. Bush, and Cuffe 99
-------
Mr. Bush: Yes, I should like to throw one other thought out here:
I think these two days have brought us, at least I hope they have
brought us, to the realization that the problem of controlling waste
disposal, trash disposal, and air pollution of the cotton gin is not
simple. It is limited by many factors, but one factor that has occurred
to me has not been discussed. This is a very real factor and one that
heavily influences a ginner's actions. It is the competitive factor.
Sometimes we find that complaints have been stimulated, justifiably
or not, by competitors, a get-even sort of proposition. These cause
everybody in the industry headaches before they finish with them.
I have in mind any number of cases over the past several years
wherein this has actually happened: Using either state, local, or
Federal authorities of one type or another to make complaints against
the competitor. It is a dirty kind of business, but it is unfortunately
true that people are people and these things occasionally happen. I
should urge that, in any deliberations that might be given to any
type of standard or whatever you want to call it, the criteria for
acceptable limits in controlling waste in and around gins include
consideration of this type problem. It causes us in the association
business untold headaches from many angles, and I think those of
you who have been in either state or Federal health departments long
enough have run into this situation.
Mr. Herzik: Mr. Bush, this is an excellent point. Having been in
public health work for 30 years, I know that the first thing we usu-
ally look at when we get a complaint and begin investigating is this:
Is it a spite thing or is it a real thing? As you imply, we frequently
find that it is a spite thing rather than a real thing, and I hope that
all health departments will continue, as we do here in Texas, to try
to separate the "wheat from the chaff" in these cases.
Mr. Graber: I should like to expand on the expression Stan
(Cuffe) used, that is, Federal standards, as it relates to what the Pub-
lic Health Service is developing. What we are developing and what
we are required to develop under the Clean Air Act are air quality
criteria. There is a difference between criteria and standards in my
opinion; criteria are amounts of various pollutants that affect people,
animals, vegetables, materials, and so forth, to a varying degree at
various concentrations and that form the basis for legal standards;
they are not in themselves standards. Our criteria are developed after
an extensive review of the literature. We are about to put out the first
air quality criteria on sulfur dioxide. To give you an example of how
it might appear, we shall list the various effects that research has
shown to occur at various concentrations. It would then be the deci-
sion of the states and communities to make their choices as to the con-
centrations they want to adopt as standards, the economic and other
factors that may be involved being considered. We are not in effect
setting national standards for air quality for specific pollutants.
100 COTTON-GINNING WASTES
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SUMMARY OF CONFERENCE
G. R. Herzik, Jr.
Chief, Environmental Sanitation Services
Texas State Department of Health
Austin, Texas
I think that this meeting, probably long overdue, has served a
very useful purpose. As far as I am concerned, there were several
real points made. One, for example, was expressed by Mr. Welsh,
who emphasized that air pollution control is a state and local respon-
sibility, and he added that cooperation among all involved is vital.
I think it could not be said more clearly than this and I am sure that
we from the state level, and I hope, the ginners themselves, agree
that this is a problem for local handling. By way of philosophizing
and not being critical, I believe that we in the states have been too
prone to let the Federal Government preempt us, not because they
are a preempting group of people, but because we fail to do what we
are supposed to be doing and to fill the vacuum, and so the Federal
Government moves in. I, too, shall emphasize, therefore, that I think
that any air pollution control, whether it is for cotton gins or other
sources, is a state and local responsibility. I hope all of us on this
level of government will make every effort to see that it stays there,
mostly by doing what we are supposed to be doing.
In regard to the cotton-ginning operations, I was impressed with
a statement, or at least an implication, by Mr. Reeves that the cost
of lost time is tremendous. Those of us in the enforcement field
should recognize that it is a pretty difficult thing, when talking with
a ginner, to be casual about putting his equipment out of operation.
I think the statement was made that it was 10 percent of his per-bale
ginning capacity for each minute lost on a 6-bale-per-hour plant,
and I am not sure that I know just what this means, but 10 percent
for 1 minute lost looks like a tremendous figure, and certainly I should
be in sympathy with anyone's objecting to losing that kind of return
on his investment. In other words, I think that what I am saying,
and rephrasing Mr. Reeve's statement, is that the equipment must be
used at maximum efficiency at all times. This, of course, will govern
the thinking of the gin operator in anything he does, whether it is
air pollution control or actual ginning.
I want to thank Mr. Bush for the complimentary remark he made
about the Texas State Health Department. I think he said something
to the effect that we helped them more than we hurt them. This
pointed out to me, or it confirms, what we have always hoped we
were doing, and that is working with industry instead of against
them. There may be times when we have wide differences of opinion,
wide disagreement, but basically, at least in this state (and I would
almost presume to speak for the other state agencies as well) we
realize that, without the support of an industry, our enforcement
program will fail of its own accord. For that reason, let me assure
Herzik 101
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you, at least for the Texas State Department of Health, that we shall
continue to work with you and not against you in every possible way.
Mr. Bush made one further remark: Owing to mechanization
we have tremendous increases in the amount of trash we have to
handle. The problem is extremely different from what it was when
I was a youngster in Fayette County in Texas. Several of my uncles
and several of my cousins have owned and today do own gins. And I
remember, as a child, the trash problem was minimal in that you
had cotton on one hand and seed on the other, and you didn't throw
either away. Now you have a big trash problem, so I can well
appreciate the fact that mechanization has changed our whole outlook
on the matter of cotton ginning.
Mr. Pendleton also emphasized the tremendous amounts of trash
and said, in effect, that we have come a great distance in handling
our problems, but there still are problems to be solved, and I believe
he said, particularly in the field of incineration. Mr. Stedronsky said
essentially the same thing; much study is still needed though com-
mendable results have been secured up to this point.
Mr. Paganini pointed out, and this to me is certainly a point to
consider, that, unless continued improvement is realized, some people
are going to bring the matter, not only of cotton gin waste, but of all
air pollution problems, before the Air Control Board in Texas. This
is probably true in other states. Remember, this is not the Board
itself or the State Health Department saying this; these are people
complaining. I think it then behooves us to take every reasonable ap-
proach that can be taken to prevent any source of complaint, or at least
eliminate any source of complaint. I look at this air pollution prob-
lem, whether from gins or other sources, very much as I do the water
pollution program.
Let me interject here that I wear several hats, that of the Health
Department representative on the Water Pollution Board, and that
of the Health Department representative on the Air Control Board.
I look with some degree of concern, tying in with the statement I
made earlier about abdication of our responsibility by allowing the
Federal government to preempt us, at what appears to be a trend
now that cost is of no significance when you are talking about con-
trolling water pollution. I see now that when people come before
the Texas Water Pollution Control Board and say they do not want
to control their sewage because it costs too much money, the enforc-
ing agencies (and this comes down from the Federal Government to
the state agencies) feel that this is a very poor method of justifying
a failure to do something. I realize that, as long as he is working on
the profit motive, it is a very serious matter to a ginner, when you
say the cost be darned, go ahead and do something. I am sure, and
this may answer several of the questions that have come up during
this conference, that in some way or other, the cost of controlling
pollution will be worked into the overall program. Whether it will be
in tax rebates, grants from the Federal or state government, or an
increase in the price of the product, I don't know; but some way or
102 COTTON-GINNING WASTES
-------
other, it is going to come into the picture. I feel that the same remark
will ultimately be made about air pollution that was made by our
Federal Government in Washington about water pollution: That it
is a national disgrace. Whether I agree with that particular evalua-
tion of the problem is beside the point; the fact is that this statement
governs pretty well the thinking of those concerned with eliminating
water pollution, and by implication will apply to air pollution. Cer-
tainly you cannot ignore the cost factor, but I am not sure that those
concerned with eliminating pollution are as concerned with it as the
ginner himself is. Be that as it may, I feel sure that, somewhere along
the line, this will work itself out. Having been in governmental
activity for so many years, I feel that, in the end, the solutions are
usually fairly reasonable, though they may sound fearful to those in
industry who read a statement or hear a public statement and say:
"This will just kill us, or this will just put the ginning industry out
of business," or, in the case of water pollution: "This will put the
plastics industry out of business, or the rayon industry out of
business." None of these industries have gone out of business, and
I am inclined to feel that, somewhere along the line, things do get
adjusted. So, while I do not want to say that we do, or should, ignore
the cost factor, I am not really as concerned with it as I am with the
feeling that, unless we do something, we will be forced to do some-
thing by "higher authority."
Nonetheless, let me say in closing, I think we have had a fine
meeting. I think we have essentially reached a meeting of the minds.
It is obvious to me that we have worked together. I am sure we shall
continue to work together. This idea has continued to impress me
during the course of the meeting. Nobody was calling anybody names;
I am sure that, as long as we can communicate with one another,
whether we are on the same side of the fence or on opposite sides of
the fence, we shall continue to solve our problems.
Herzik 103
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BIBLIOGRAPHIC: Control and disposal of cotton-
ginning wastes. A symposium. May 3-4, 1966. PHS
Publ. No. 999-AP-31. 1966. 103 pp.
ABSTRACT: This symposium on the control and dis-
posal of cotton-ginning wastes, held in Dallas, Texas,
in May 1966, was jointly sponsored by the Division
of Air Pollution, Public Health Service, U. S. Depart-
ment of Health, Education, and Welfare, and the
Agricultural Engineering Research Division, Agri-
cultural Research Service, U. S. Department of Agri-
culture. The proceedings contain information on the
following subjects: the roles of local, state, and Fed-
eral agencies in controlling air pollution; the roles
of the state extension's gin and mechanization spe-
cialists; methods employed in harvesting cotton;
operations and characteristics of the cotton gin;
methods of collecting seed cotton trash; current gin
trash disposal practices; methods of collecting lint
cotton trash; air pollution study of cotton gins in
Texas; defoliants and pesticides; trash collection and
disposal system; design and operation of the in-line
filter; considerations for determining acceptable
ambient and source concentrations for particulates
from cotton gins; and recommendations for needed
research and development.
BIBLIOGRAPHIC: Control and disposal of cotton-
ginning wastes. A symposium. May 3-4, 1966. PHS
Publ. No. 999-AP-31. 1966. 103 pp.
ABSTRACT: This symposium on the control and dis-
posal of cotton-ginning wastes, held in Dallas, Texas,
in May 1966, was jointly sponsored by the Division
of Air Pollution, Public Health Service, U. S. Depart-
ment of Health, Education, and Welfare, and the
Agricultural Engineering Research Division, Agri-
cultural Research Service, U. S. Department of Agri-
culture. The proceedings contain information on the
following subjects: the roles of local, state, and Fed-
eral agencies in controlling air pollution; the roles
of the state extension's gin and mechanization spe-
cialists; methods employed in harvesting cotton;
operations and characteristics of the cotton gin;
methods of collecting seed cotton trash; current gin
trash disposal practices; methods of collecting lint
cotton trash; air pollution study of cotton gins in
Texas; defoliants and pesticides; trash collection and
disposal system; design and operation of the in-line
filter; considerations for determining acceptable
ambient and source concentrations for particulates
from cotton gins; and recommendations for needed
research and development.
BIBLIOGRAPHIC: Control and disposal of cotton-
ginning wastes. A symposium. May 3-4, 1966. PHS
Publ. No. 999-AP-31. 1966. 103 pp.
ABSTRACT: This symposium on the control and dis-
posal of cotton-ginning wastes, held in Dallas, Texas,
in May 1966, was jointly sponsored by the Division
of Air Pollution, Public Health Service, U. S. Depart-
ment of Health, Education, and Welfare, and the
Agricultural Engineering Research Division, Agri-
cultural Research Service, U. S. Department of Agri-
culture. The proceedings contain information on the
following subjects: the roles of local, state, and Fed-
eral agencies in controlling air pollution; the roles
of the state extension's gin and mechanization spe-
cialists; methods employed in harvesting cotton;
operations and characteristics of the cotton gin;
methods of collecting seed cotton trash; current gin
trash disposal practices; methods of collecting lint
cotton trash; air pollution study of cotton gins in
Texas; defoliants and pesticides; trash collection and
disposal system; design and operation of the in-line
filter; considerations for determining acceptable
ambient and source concentrations for particulates
from cotton gins; and recommendations for needed
research and development.
ACCESSION NO.
KEY WORDS:
air pollution
cotton ginning
dust
lint
collection
disposal
wastes
particulates
defoliants
pesticides
research
development
ACCESSION NO.
KEY WORDS:
air pollution
cotton ginning
dust
lint
collection
disposal
wastes
particulates
defoliants
pesticides
research
development
ACCESSION NO.
KEY WORDS:
air pollution
cotton ginning
dust
lint
collection
disposal
wastes
particulates
defoliants
pesticides
research
development
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