Public Health Service


                     A Symposium
                     Sponsored by
         National Center for Air Pollution Control
                  Public Health Service
      U. S. Department of Health, Education, and Welfare
         Agricultural Engineering Research Division
               Agricultural Research Service
              U. S. Department of Agriculture
                     Dallas, Texas
                   May 3 and 4,  1966
                  Public Health Service
               Bureau of Disease Prevention
                and Environmental Control
                     Cincinnati, Ohio

   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

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

                  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

    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

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

                  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

    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

    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-

    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

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.
                                    COTTON-GINNING WASTES



                    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.
    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

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

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

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

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.



                                                   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.


    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

      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
      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
     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


     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

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

    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.

                  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

       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

                         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

elevated bottom-dump bins that dump directly into hauling equip-

                    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.

                        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

    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
    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

    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



                                                    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

     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

    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.

    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

    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

    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.

    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

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.

    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.

    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

    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
22                                  COTTON-GINNING WASTES

    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


                 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

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

    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

     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

     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

    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


                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

    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.
Sticks and stems
Leaf and dirt
    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.
               (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
    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

                   VACUUM DROPPER
                -  SUCTION
                                             EED CONTROL
                 Figure 1 — Typical seed cotton-unloading system.
                                      CYLINDER CLEANER
              Figure 2 — Typical seed cotton drier-cleaner installation.
 Moore and  McCaskill

       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

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.
              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

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.
DIA — DC   DIA — Do    DIA — DC
                                CYCLONE DESIGN  PROPORTIONS
                                    D  = °
                                          0 2
                                       = 2D
                                    S0 = °0 8

                                    Z0 = 2DC
                                    J  = 12 in. (MINIMUM)
                Figure 5 — Dimensions of a small-diameter cyclone.
    Figure 6 — Inlet transition proportions for multiple small-diameter-cyclone mounting.
                                         COTTON-GINNING WASTES

                           TRASH INLET
IN GIN UKUr-r-E.K-*7^;
//*"~\ v*"-^ y

             Figure 7 — Trash collection system for a battery of cyclones.
     TRASH FROM  _

                                  LARGE TRASH HOUSE
          Figure 8 — Collecting trash from a battery of cyclones for disposal.
Moore and McCaskill

    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.

                   DISCHARGE  VELOCITY)
Width, ft

Height, ft

    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, 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.
                                                  SWEEPER BRUSHES
                                                  CARRIER CHAIN
                                                   ARRESTOR MEDIA
                                                  EXPANDED METAL
     Figure 9 — One type of filter for removing foreign matter from cyclone exhaust.
                               TO TRASH
                               HOUSE OR
                                                         AIR FILTER
                                  CLEANOUT DOOR   '

   Figure 10 — Typical installation of filter for cleaning air from a battery of cyclones.
Moore  and McCaskill

    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.
                                         AUTOMATIC AIR FILTER
                                                 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.


    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.)
                                     COTTON-GINNING WASTES


                                               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.

                           OF 1964"
Method, %
Machine picked
Machine stripped
Machine scrapped
U. S. A.
_ —
Miss. S. C.
31 37
1 —
68 63
— —
— —
                       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
Machine picked
Machine stripped
Machine scrapped
"Source: U. S. Department of Agriculture.

            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
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).


 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.


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


"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
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

               COTTON GINS,  1965-66 SEASON"
United States

South Carolina
North Carolina
New Mexico
United States
"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

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

              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



                                                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

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

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

    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

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

    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-

    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
50                                  COTTON-GINNING WASTES



                                                   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

    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

    5. conclude whether problems are of sufficient  magnitude to
       warrant study and research.
52                                  COTTON-GINNING WASTES

    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

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,

    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
54                                  COTTON-GINNING WASTES

    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
    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

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

    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

    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.

                           David F. Pugh, M.D.
                           Diplomate, American Board of Pediatrics
                           Associate Fellow, American Academy
                           of American College of Biology
58                                   COTTON-GINNING WASTES


                                                 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.

                     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

    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

                IN TEXAS, 1947 THROUGH 1965

                 %                         %             Total %
      Spindle machine  No. of   Stripper  machine  No. of   machine
Year  pickers  picked  counties harvesters stripped counties harvested



    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

    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

    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


                                                Andrew O'Neal
                                      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


                                              Travis C. McLain
                                               Project  Engineer
                                   Research and Design Division
                                   Continental/Moss Gordin, Inc.
                                             Prattville,  Alabama


    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
    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.

     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).
                     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.
    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

 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.
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.
.  1.2
                                      PRESSURE SWITCH
                                        GOOD FLY AND
                                        DUST REMOVAL
              GOOD FLY RE-
             MOVAL BUT POOR
              DUST REMOVAL
                             1.0         1.5
                           LENGTH OF CYCLE, min.
 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.

                                           GOOD FLY AND
                                           DUST REMOVAL

                           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-
                       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.
            GOOD FLY
          REMOVAL BUT
           POOR DUST
         — REMOVAL
                                  PRESSURE SWITCH
                   0.5         1.0        1.5

                          LENGTH OF CYCLE, min.
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-



     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.
















                       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-
                       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.


    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.

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.


    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-


]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
 McLain                                                        77

                 FROM  COTTON GINS

                                              Stanley T. Cuffe
                                            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.


    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-

or area
Unit of
Visibility in
or goal
Sufficient to reduce vis-
ibility to less than 3
miles when the rela-
tive humidity is less
than 70 percent.
Oregon6      Nonspecific
                Suspended /ig/m3             150C         250C
                Settleable  tons/mi2/month     15C          30C

              Lime dust
                Suspended /ig/m3              20C          —
                Settleable  tons/mi2/month      lc          —
St. Louis
75 annual geometric
 200d annual 99th
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

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

                  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).


   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.

                    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
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
84                                   COTTON-GINNING WASTES

                 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
                                  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

    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.

                   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
86                                   COTTON-GINNING WASTES

                        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
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.

                 STONEVILLE COTTON GIN (18)
Unloading fan
Stick and bur
  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.


    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.


 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,
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


                                                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

                   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
    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

  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

    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

    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

    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

    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,

    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

    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

    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

    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?
    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


                                                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

 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

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.

 air pollution
 cotton ginning

 air pollution
 cotton ginning

 air pollution
 cotton ginning