W 34th STREET / GAINESVILLE. FLORIDA 32601 / PHONE 904/372-3318 environmental engineering. inc. DRAFT BACKGROUND INFORMATION FOR ESTABLISHMENT OF NATIONAL STANDARDS OF PERFORMANCE FOR NEW SOURCES COTTON GINNING INDUSTRY Contract No. CPA 70-142 Task Order No. 6 Prepared for Industrial Standards Branch Division of Applied Technology Office of Air Programs Environmental Protection Agency Raleigh, North Carolina by Environmental Engineering, Inc. July 15, 1971 ------- TABLE OF CONTENTS SECTION DESCRIPTION PAGE 1.0 INTRODUCTION 1-1 1.1 The Cotton Industry 1-1 1.2 Cotton Ginning 1-3 2.0 PROCESS DESCRIPTION 2-1 2.1 General 2-1 2.2 The Ginning Process 2-5 3.0 EMISSIONS FROM COTTON GINS 3-1 3.1 Emissions from the Gin Building 3-1 4.0 CONTROL TECHNOLOGY 4-1 4.1 Description of Equipment 4-1 4.2 Emission Control System 4-6 4.3 Cost of Control Systems 4-6 5.0 COTTON GINS UTILIZING THE BEST TECHNOLOGY 5-1 6.0 SPECIFIC REGULATIONS CURRENTLY PERTAINING TO THE COTTON INDUSTRY 6-1 6.1 Particulate Matter 6-1 6.2 Odors 6-3 7.0 RECOMMENDED STANDARDS OF PERFORMANCE FOR NEW GINS 7-1 8.0 PRODUCTION AND GROWTH OF THE COTTON GINNING ------- ------- SECTION DESCRIPTION PAGE 9.0 REFERENCES 9-1 9.1 References Cited 9-1 9.2 Associations 9-2 9.3 Manufacturers 9-3 ------- NATIONAL STANDARDS OF PERFORMANCE COTTON GINNING INDUSTRY 1.0 INTRODUCTION 1.1 The Cotton Industry The cotton industry is an international industry and is therefore subject to many decisions made outside of the United States. In 1970-71 (the last quarter of 1970 and the first quarter of 1971) the projected free-world cotton consumption was 28.3 million bales. The 1970 U.S. pro- duction was 10.1 million bales. As well as being an international industry the cotton market is part of the total fiber industry. The 1970-71 free-world consumption of fibers was 59.7 million bales (equivalent cotton i»les). Synthetic fibers accounted for 31.4 million bales of this. The major difference in the consumption of these two fibers is that the cotton consumption has in- creased only 3.7 million bales in the past decade (16 percent) while the synthetic fiber consumption has increased 19.5 million bales (164 percent). The trend in the U.S. market, where 85-90 percent of the U.S. produced cotton is consumed, has improved recently as far as the cotton industry is concerned. After a steady decline for cotton in the total U.S. fiber market during the 1960's, including a drastic drop in 1968, the cotton percentage leveled out during 1969 and 1970. An analysis of the U.S. economy and the textile market by the National Cotton Council of America (NCCA) indicates that cotton consumption is now holding its own and will perhaps increase slowly in the future There are several factors which may change this picture, how- ------- shortages brought about by decreased cotton acreages and/or unfavorable weather, cotton price gyrations brought about by speculation-in the cotton market, and, in the U.S., federally imposed cotton acreage quotes and federally sponsored price support programs. The latter programs are authorized by Food and Agriculture Acts. There will be no federal support programs during the 1971 and 1972 seasons. Because of the number and complexity of all the factors influencing the cotton market the National Cotton Council finds it impossible to project the future of cotton even one year. All of the ramifications involved are detailed in the NCCA report^. For purposes of projecting the potential of the air pollution problem of the cotton ginning industry, an estimate of growth can.be made based upon historic records of cotton production and the trend that indicates cotton is now holding its own in the world fiber market. Historically, the production of cotton in the United States is very unique in that the annual production rate has remained-generally constant since 1899. In that year 9.4 million bales of cotton were produced in the U.S. In 1970, 10.1 million bales were produced. During this 72 year period the U.S. production has ranged from a low of 7.4 million bales in 1967 to a high of 18.3 million bales in 1937. The average production during this period has been 12.4 million bales annually. For purposes of estimating the air pollution potential.of the cotton ginning industry over the next decade, it appears reason- able to assume that the production of cotton will remain in the 9-14 million blaes per year range. ------- This appears to be quite a range, but it is within-the current production fluctuation and can be accomodated at existing gins simply by varying the duration of the ginning day or season. 1.2 Cotton Ginning Cotton ginning involves receiving seed cotton at the gin, removing the green bolls and rocks; drying and removing sticks, field trash and leaves; ginning the cotton to remove the cotton seed; and cleaning and baling the lint. The cotton seeds are collected for oil production or for future planting. The trash and lint from the cotton is either incinerated, composted, or spread on fields. 1.2.1 The Cotton Ginning Industry Although the production of cotton has remained quite constant during the past 70 years, several changes have occurred in the ginning industry. Probably the most important changes have been the develop- ments and improvements in ginning equipment and the effects that these have had on the capacities of gins. In 1899, there were 29,620 active cotton gins in the U.S. and each gin averaged 317 bales of cotton per year (a bale of lint cotton has a nominal weight of 500 lbs). In 1969, there were only 3,943 active gins in the country, and each ginned an average of 2,522 bales of cotton annually. Current projections are for cotton gins to continue to increase in size. It has been reported that presently a gin must have a capacity of 4,000-10,000 bales of cotton annually, depending upon the ginning rate, to break even financially^—'—'—^. ------- The ginning rates for gins range from 5 bales per hour for old gins to 20-30 bales per hour for newly constructed gins. An average gin is rated at 10-15 bales/hr. The increase in gin size has been made feasible by improvements in equipment and by automotive transportation, and it has been made nec- essary by increased capital and labor costs and a reduction in the length of the ginning season as a result of the mechanical harvesting of cotton. 1.2.2 Geographic Distribution The cotton belt of the U.S. stretches across the southern part of the country from coast to coast as shown in Figure 1. The distribution of cotton gins pretty much parallels the distribution of cotton production. Table 1 shows the distribution of cotton gins in the U.S. The number of cotton gins reported at any time is approximate since some gins do not operate each season. 1.2.3 Period of Operation Cotton ginning is a seasonal industry. It begins with the maturing of cotton, which varies somewhat with geographic distribution, and ends shortly after the cotton harvest ends. This period begins around mid to late October, and extends through early January. The reason the ginning season follows the harvest of cotton so closely is that cotton fiber is degradated during storage. ------- ;.t temn AfltZ >, OKLA 'MISS I ,11 I .1 | 1.1 J. 1-1,1 Jj I .Ml. ' II .1111 III . 11,11 II, IJ-II.II.Mffl l.l.ll-1 '-U- IIII.H. I. WWII ¦¦¦III IB . n I|.I«IIPIHIWI lip WW.. IWHli.ilHilHili.ll.UM.ilH ¦¦ . n UN! I.n . I ¦ ! II U I ¦ 11 HII.U III ¦¦mill Production of Cotton in the United States Each dot represents 5,000 bales FIGURE 1 National Cotton Council ------- TABLE 1 NUMBER OF ACTIVE COTTON GINS IN EACH STATE; 1968* State No. of Gins State No. of Gins Georgia 255 Tennessee Alabama 339 Missouri 115** S. Carolina 224 Kentucky 1** N. Carolina 143 Texas 1300 Virginia 7 Oklahoma 145 Florida 5 Arizona 116 Louisiana 181** California 291 Arkansas 451 New Mexico 58 Mississippi 511** Nevada 1 Total U.S. 1968 Total U.S. 1970 4218 3754 Data from Cotton Division, Consumer and Marketing Service, U.S. Department of Agriculture 1970 Data ------- The season for an individual gin is usually only 4-6 weeks. This may tail out somewhat depending upon lagging cotton harvesting, but the peak production period is 4-6 weeks. The remainder of the year the gin is idle. 1.2.4 Cost of Ginning Cotton The cost per bale of lint cotton varies considerably through- out cotton belt and it varies considerably within a region from year to year. In 1966, the average cost to produce a bale of Upland cotton in the U.S. was $132.84. The costs ranged from $90.57 in the high plains of Texas to $184.39 in eastern Arkansas The 1966 cost of ginning averaged $18.36 (13.8 percent of the total cost) in the U.S., with a range of $14.45 to $21.24 (8.7-18.5 per- (5) cent) - . In general, the lowest ginning costs were incurred in the southeast where hand picking was still practiced to a significant extent. This method of harvest has declined considerably since 1966. The highest ginning costs were incurred in the southcentral section of the cotton belt from the Mississippi River to western Texas. Machine stripping is the predominant method of cotton harvest in this section of the cotton belt. The U.S. Department of Agriculture Economic Research Service has conducted a study subsequent to the 1966 study, but results have not yet been published. ------- 2.0 PROCESS DESCRIPTION 2.1 General Cotton ginning involves separating cotton fibers from cotton seed and other field trash. Materials are transported through the gins pneumatically and sources of air pollution result each time material is separated from the air stream. Factors which affect the ginning process are the type of cotton being ginned, the method of harvest, and the moisture content of the seed cotton. 2.1.1 Jlypes of Cotton The two types of cotton produced in the U.S. are Upland cotton and American Prima or American Egyptian cotton. Upland cotton accounts for about 99.2 percent of the cotton produced. Thejnain difference in_the two species is the staple length (fiber length). The staple length of the Upland cotton ranges from 15/16 inch to 1 5/32 inch, depending upon the particular variety. JThe_ staple length of the American Prima cotton is longer; ranging from 1 3/8 inch to 1 9/16 inch. American Prima cotton is produced in the El Paso, Texas area, the Carlsbad, New Mexico area, and the Phoenix, Arizona area. The difference in the ginning processes for these two cotton species is in the gin stand. For theAmerican Pni.ma_co.tton. a roller type or McCarthy gin jjLused. This gin resembles a clothes wringer. ------- The two rollers have bearings which permit the rollers to wedge together close enough to grip the cotton fibers and to separate them from the seed. These gins are usually of a low capacity, but they do prevent breakage of the long American Prima cotton fibers. The Upland cotton is ginned with a saw type gin which will be discussed in Section 2.2.5. ^ The air pollution problems of the two types of gins are similar. The main difference is that the Upland cotton gins are usually of a higher capacity and, hence, have an air pollution pro- blem of a greater magnitude. 2.1.2 Methods of Harvest The method of harvesting cotton determines the amount of trash in the cotton and, hence, determines the amount of cleaning equipment required at a gin. (In this and succeding sections of this report reference is made to bales of cotton and bales of seed cotton. Seed cotton is cotton as it is received from the field. It contains the cotton fiber, cotton seed, and field trash. Cotton or lint cotton refers to cotton fiber as it leaves the gin. The nominal weight of a bale of lint cotton is 500 pounds. The weight of a bale of seed cotton is the weight of seed cotton which is required to produce a bale of lint cotton. This weight will usually vary from 1300-2500 pounds, depending upon the method of harvest.} ------- There are five methods of harvest presently used for cotton; three mechanical and two manual. The methods are machine picking, machine stripping, machine scrapping, hand picking, and hand snapping. The latter two methods are fast becoming obsolete because of the cost of labor and improvements in harvesting equipment. Hand picking was the method originally used for harvesting cotton, and it produces the cleanest seed cotton; approximately 50-100 pounds of trash per bale of cotton. Table 2 presents the approximate weight of materials in a bale of seed cotton for various harvest methods. The amount of trash varies considerably and depends upon field conditions at harvest time, machine conditions, and the skill of the operator. Toward the end of the season the trash content can be as high as 2000 pounds/bale. The methods of harvest which are most prevalent are machine stripping and machine picking. In 1966, machine picking accounted for 62 percent of all harvested cotton in the U.S. and machine stripping (5) accounted for 27 percent —: These percentages have increased since then. Machine stripping is most common in Texas and New Mexico, where 96 per- cent of the cotton is harvested by this method. Machine picking is common throughout the remainder of the cotton belt, In addition to controlling the amount of cleaning equipment the method of harvest also determines the amount of trash generated. When ginning 20 bales/hr of machine picked cotton, 3280 lbs/hr of ------- TABLE 2 COMPOSITION OF SEED COTTON PER 500 lb BALE OF COTTON Method of Weight of Weight of Weight of Weight of Harvest Seed Cotton Cottonseed Trash Moisture Lint Hand picked 1,383 808 75 500 Hand scrapped 2,049 808 741* 500 Machine picked 1,472 808 164* 500 Machine stripped 2,159 808 851* 500 Machine scrapped 2,473 808 1,165* 500 * Average Values from 1964 U.S. Cotton Crop^ ------- trash are produced. With machine stripped cotton, on the other hand, the trash produced is 17,020 lbs/hr. If this material is disposed of by incineration, the potential for air pollution is changed con- siderably. 2.1.3 Moisture Content of Seed Cotton The moisture content of seed cotton is critical in the storage and ginning of cotton. Ideally, cotton should be harvested when the moisture content of the lint is less than 10 percent. Seed cotton with this moisture content can be stored without degradation and moisture adjustments prior to ginning are minimized. For ginning, the moisture content of the lint should be 6.5 to 8 percent. A moisture content higher than this improves the - yarn strength and appearance, but decreases the lint grade; a lower moisture content increases the grade, but decreases strength and appearance. The result of this is that the moisture content of the lint is adjusted prior to ginning. The usual adjustment is to decrease the moisture content by drying. Only in the arid southwest is it sometimes necessary to increase the moisture content of the lint. 2.2 The Ginning Process The major objective during the ginning process is to obtain the maximum dollar return for the cotton producer and to maintain fiber quality for the manufacturer and consumer. The selection and proper ------- use of ginning equipment as determined by the type of cotton, the condition of cotton, method of harvest, moisture content of the lint, and the status of the market has a great influence on attaining this objective. A typical arrangement of ginning equipment is: 1. suction unloading telescope, 2. green-boil trap, 3. air line cleaner (recommended only in sandy areas to protect the machinery from abrasion). 4. bulk feed control unit, 5. dryer (24-shelf tower or equivalent) with 3-mi11 ion BTU burner with modulating or automatic moisture- sensitive control,* 6. a 6- or 7-cylinder inclined cleaner with grid selec- tion , 7. bur machine, 8. green leaf and stick machine, 9. dryer (24-shelf tower or equivaleent) with 3-mi11 ion BTU burner with modulating or automatic moisture- sensitive control,* 10. a 6- or 7-cylinder inclined cleaner with grid selection, 11. extractor feeders, 12. gin stands, 13. tandem saw-type cleaning with complete bypass system, 14. press. *Dryers should have a bypass in case lint does not require drying. In the High plains area of Texas, moisture restoration equipment would be included along with the dryers. ------- Figure 2 shows a flow diagram of a typical cotton gin„ Figures 3, 4, and 5 show some basic modifications to the gin layout for specific conditions. These diagrams stop with the gin stand since they are similar to Figure 2 beyond this point. Figure 3 shows a machinery layout for hand picked cotton. There are still some gins of this type in the Carolinas, Georgia, and Alabama. Little cleani/ig is necessary on the relatively clean early season, hand-picked cottons. A master feed-control unit to meter the seed cotton into the system, a full tower drier or the equivalent, 7 to 14 cylinders of seed cotton cleaning, a bur or stick-and-green- leaf machine, and large extractor feeders, are all the machinery necessary to produce satisfactory grades from clean, hand-picked cottons. For machine-picked cotton, a much more elaborate gin is necessary to obtain grades acceptable to the mills and to yield good returns for the producer. The Midsouth has more moisture generally than does the Southeast; therefore, more drying of the cotton is needed. Because of moisture that is added on the picker spindles, more drying is generally needed on the machine-picked than on the hand-picked cottons. A gin to handle machine picked cotton is shown in Figure 4. It consists of a feed control, 2 full-sized tower driers or the equivalent, a boll trap, 12 to 14 cylinders of seed cotton cleaning, a bur machine or stick- and-green-leaf machine, large extractor feeders, and 2 lint cleaners. Considerable extracting equipment is necessary to obtain satisfactory grades for machine-stripped cottons. Also, an air-line ------- Storage House (A) (C) (S) (t) iNEl^vilr, Cotton, Seed 4 Traah COTTON- > *— o Boll C.S.T Field W agon tm Catcher Boll Catcher Optional Location C»5,T Air A&T © Main Cleane r Hot Air Dryer Stick and Burr Cleane r Vacuum Sepa rator O Main Cleaner Dist ributor Extractor Feede rs Hot Air Dryer La r Motes & Pin txajh Fan OQ CO A AJtT y Lint Cleane rs r < ' Air & Lint C Air i Lint Air & LLnt Waste Amounts (Dust, Surra, Moats. P.n Trash Lint) Hand Picked Cotton - Less than 73 lbs per nnished bale Machine Picked Cotton - Over 75 lbs per finished bale Defoliate, Snapped and Machine Picked Cotton - 300 to 2, 000 lbs per finisned bale 95% is estirrated to be discharged through mam cleaner fan exhausts, balance through suction, pin trash-moats-lint clean- er fan exhausts. Gin Stands dOMM conveyor Collector and Seed House acuurr. Box Sepa rator Press Condense r Fan Cotton Bale Air and trash discharged directly to atmosphere or dust collectors Note The number of dryers and cleaners v-ill vary uith each gin O© and fly lint discharged directl> to atmosphere or through "dog and area harvesting methods houses" (settling chambers) or fly lint catchers FIGURE 2-TYPICAL COTTON GINNING FLOW DIAGRAM ------- disrsiBvro* DP/CP UHT fiUC \ seeocorrcH input - reeo control t*rpac top rccocp FIGURE 3 —Ciiuiiiip m.icliincr* setup recommended for u«e >»Jlh cJctjn, Jmnil-pickcd coiton* • seeo CO T tow inpu r •fXCO CONTPOL ,£X TPAC TOP FIGURE 4—Ginning machinery setup recommended for use on machine'picked cotton. COTTON INPUT Ft 10 CONTPOL aip t/ftr ClfANtP MA CM mfATfP STICK 0CHOVCP HgA Tea rcue N f \ romCfi \ TOWS* OPltP 1 OPUP t J DUTPlB'J TOP iA»ce CXT0ACTOP fClota LINT CLfANtPS FIGURE 5 —Ginning machinery setup recommended for use on machine-stripped and hanil-siiapped cotiou. ------- cleaner in the wagon unloading line is advisable. Machinery recom- mendations for handling hand-snapped and machine-stripped cotton in Oklahoma and the High Plains include a feed control, green boll trap, 6- or 7-cylinder air-line cleaner, tower drier or equivalent, 6- or 7-cylinder cleaner, large extractor feeders, and 2 lint cleaners (Figure 5). 2.2.1 GreerbzBoll Tra-e—„ 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 boll are likely to stick to gin saws and cause a considerable reduction in the gin plant efficiency. 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. Figures 6 and 7 show two types of green-boll traps. The type shown in Figure 7 will remove 87-92 percent of the green-bolls with a lint loss of less than 1/4 pound per bale. 2.2.2 Feed Control Gin plants should be equipped with a bulk uniform-feed control unit. The unit should be located in the machinery 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, since this results in a recirculation of the overflow cotton through the overhead clean and drying equipment. ------- r, open bolls baffle o °# O e? a o "Q £ f7 ^ a. xJT ° ^ j ^ 0%f% 6°m\ c, i * o<° -green bolls 0 , cr* <'2a° -open 8 green bolls fez FIGURE 6—Comcnlional green-boll Irap. open bolls reclgngular suction duct feed rate regulator loyer of open a V green boll* \ 7 45l. Q/^a".c Q-'aa 3s»J o^VoS f eonv< -k | 1 L- green bolls ( conveyor bait FIGURE 7 -n \pci iniciit.il trap ------- 2.2.3 Dryers and Moisture Regulation The amount of moisture in seed cotton during cleaning and ginning is the most important factor affecting cotton quality. Temper- atures of the dryer or the dryer by-pass mechanism should be adjusted on the basis of the moisture in the wagon sample and in the lint at the lint slide (entering the press). 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. Wet cotton passes through the cleaning equipment in wads that may cause chokages and inefficient cleaning. When cotton is ginned, damp samples are not as clean or as smooth, and lower grades result. If cotton is ginned while exces- sively 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. These facts emphasize the importance of fiber moisture during ginning, and the part controlled drying and moisture restoration play in efficient ginning. Figure 8 shows the cross-section of a typical shelf dryer. 2.2.4 Cleaners and Extractors Seed cotton contains burs, bracts, sticks, stems, dead leaves, and sometimes green leaves. Each type of trash involves a special type of cleaning job. - cyj-j-miuv-iyim n-a.ff thn mttnp anH r.flmQV*- ^.sand-,—f-ine-l-ea-f-T-af^-bra"ct-p^ta?-¦ h.,r msr -tjy^e^of^c.lean-wg-^otr. Cylinder-type cleaners fluff the cotton and remove sand, fine leaf, and bract particles; bur machines extract sticks and ------- SEPARATOR 1 OlACCTIONAL VALVE COTTON INLET MOT-AIR INLET OlRECTtONAL VALVE COTTON INLETS DRY COTTON OISCHARGE VACUUM FECDCftl FIGLRE 8—USDA-dc\cloped muhipatli seed cotton drier for controlled exposure drying. FIGURE 9—Cross section of 7-e)Iinder inclined cleaner. ------- burs; green leaf and stick machines extract, burs, sticks, stems, and green leaves. Since the bur machine is an efficient, high-capacity dry-bur extractor, good results are obtained 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 removal. 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 alternatelyjn 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. Figures 9 and 10 show various pieces of cleaning equipment. 2.2.5 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. Figure 11 shows a cross-section of a gin stand. ------- FIGURE 1 0 Ooss section of bur machine (left) with stick rcmo\or attachment added (right). Lint Cleaned Seed Cotton (1) Huller rib (2) Doffing brush (3) Saw (4) Ginning rib Seed FIGURE 11-Cross section of a Saw type gin ------- 2.2.6 Lint Cleaners The use of lint cleaners in cotton gins is now as accepted practice, with more than 90 percent of the gins employing one or more lint cleaners. This development enables the ginner for the first time to remove foreign matter from lint cotton as a continuous process of ginning. It has contributed greatly to the success of cotton mechan- ization and mechanical harvesting. Lint cleaners can remove effectively and efficiently small leaf particles^ motes,green leaves, and grass left in the cotton by seed cotton cleaners and extractors. Lint cleaners are generally grouped into two categories, unit and bulk (battery). The unit machine implies_th_at there will be one unit for each gin stand. A lint cleaner that receives lint from two or more gins is referred to as a bulk lint cleaner. Lint cleaners, either unit or bulk, placed in series so that the same lint passes through both of them result in what is commonly called tandem lint cleaning. The use of one or two saw-type lint cleaners is an accepted practice, but the use of more than two in series should be discouraged since the appearance and strength of the yarn will be decreased. Effectiveness of trash removal and grade improvements benefits resulting from use of lint cleaners are well established. But when grades are improved, bale weights and values are affected. Bale weights are reduced from 7 to 50 pounds or more per bale depending on harvesting practices, number of lint cleaners, and grades of cotton being ginned. Thus, improvements in grade may be offset by losses in bale weight. ------- With tandem saw-type lint cleaners, the first cleaner removes the most weight; the second, about half as much as the first; and the third, about half as much as the second. The foreign matter removed is composed of motes, fine leaf particles, grass, and green leaf in vary- ing amounts. Figure 12 shows the cross-section of a lint cleaner. 2.2.7 Condensers Condensers employ either one or two slow-turning screened drums on which the ginned lint forms a batt. The batt is discharged between doffing rollers to the lint side. Thejfai~r^ separated from the lint by venting the air through the screened drum to its ends where it is discharged in the direction provided in the manufacturers' design. The condenser is similar to the condenser in the top part of the lint cleaner shown in Figure 12. 2.2.8 Bale Presses The lint batt is fed into a hydraulically operated press which compresses the lint into 500 pound bales. The presses are classified as low-, medium-, or high-density presses. These presses produce bales with densities of 12, 24, and 36 pounds of cotton per cubic foot, respectively. 2.2.9 Cotton Seed Handling Cotton seed is removed from the gin stand either by mechanical or pneumatic conveyors and transported to seed storage bins. From the bins, the seed is either bagged or removed in bulk to cotton seed oil mills or it is returned to the cotton producer for future planting. ------- TRASH FIGURE 12-Unit controlled-batt saw-type lint cleaner. ------- 2.2.10 Air Systems The air handling system in a cotton gin can be separated into a high pressure system and a low pressure system. The high pressure system includes the system from the suction unloader up through the trash fan on the ljnt cleaners. This system operates against a pressure of 10-20 inches of water. The most common <• - — ¦ — - type of emission control^ on this system is the small diameter cyclone (Figure 2). The lint condenser and the waste lint condenser exhausts com- prise the low pressure system. This system operates against a pressure 1-5 inches of water. Control equipment for this system is primarily a filter type (Figure 2). The volume of air handled at a gin is 50-75,000 cfm for an 8 bale/hr gin and 65-80,000 cfm for a 12 bale/hr gin. A gin located at the USDA Cotton Ginning Research Laboratory in Stoneville, Miss, was tested for particulate emissions in 1970. The air fl«ws at an 8.7 bale/hr ginning rate were: High Pressure Unloader fan 4,248 cfm 6 cylinder cleaner and stick machine 7,346 6 cylinder cleaner 8,436 Trash fan 8,208 28,238 cfm ------- Low Pressure No. 1 Lint cleaner - 15,800 cfm No. 2 Lint cleaner 6,438 Battery lint cleaner - 15,874 Lint cleaner waste - 14,776 52,888 cfm 81 ,126 cfm 2.2.11 Capital Cost Cotton gins are generally designed and constructed by gin manufacturers on a turnkey basis. Therefore, the total cost for the construction of a new gin is easily obtained. 18-30 bale/hour category. The construction cost for these qins range from $350,000 to $500,000. This cost includes $15,000 - $30,000 for emission control equipment. The largest gin in the U.S. was recently built for the J.G. Boswell Company of Corcoran, California, by the Continental, Moss Gorden Gin Company. This gin is completely automated and is rated at 40 bales/hr. The annual capacity is expected to be 33-35,000 bales. me tub i, ui tn ib ym wdb 4>i.3 miiiiuri. Presently, the new gins that are being constructed are in the ------- 3.0 EMISSIONS FROM COTTON GINS Emissions from cotton gins consist of hulls, sticks, stems, leaves, and dirt from the high pressure system (see section 2.2.10), and lint fly from the low pressure system. An activity associated with cotton ginning is the disposal of the large volumes of trash removed from the seed cotton. The methods of disposal most commonly used are incineration, composting, spreading on the land, and use as cattle feed. With incineration there is a great potential for air pollution and with composting there is the possibility of odors if the process is not maintained properly. Ambient air samplinq in the vicinity of cotton gins has shown high concentrations of particulate matter, arsenic and bacteria. 3.1 Emissions from the Gin Building 3.1.1 High Pressure System The emissions from the high pressure system consist of burs, sticks, leaves, and dirt which are brought to the gin with the seed cotton. The amount of this material per bale depends upon the method of harvest, the condition of the cotton and field, and the skill of the operator. Table 3 shows the quantity and composition of trash per bale for three methods of harvest. Points of emission are shown in Figure2. Emission tests have, been conducted at the USDA Cotton Ginning Research Laboratories in Stoneville, Mississippi^ and Mesilla Park, New Mexico^. The ------- TABLE 3 QUANTITY AND COMPOSITION OF TRASH PER BALE OF COTTON LINT Harvest Method Trash Machine Picked Machine Stripped Machine ScraDDed -lulls 29 lb/bale 397 lb/bale 329 lb/bale Sticks and Stems 9 50 143 .eaves and Dust 43 78 398 Total 81 525 870 Typical Range 75-164 lb/bale 447-1030 lb/bale 870-1300 lb/bale ------- results of these tests are shown in Tables 4 and 5. Both of these plants are equipped with small diameter cyclones an.d lint filters. Several things are apparent from the two tables: 1) When ginning machine picked cotton with a trash content of 90 lb/bale, the emissions from the high pressure system average only 9.7 percent of the total gin emissions, whereas when ginning machine stripped cotton with trash contents varying from 447 -1,308 lb/bale, the high pressure system emis- sions account for 36.4 - 65.4 percent of the gin emissions. 2) The total emissions from- the high pressure system are dependent upon the trash content of the seed cotton. 3) The unloader fan is the greatest single source of emissions in the high pressure system. This is especially true with ginning machine picked cotton. (8) Other tests conducted by Baker — indicated that emissions are not proportional! to the qinnina rate. Results showed that there was a significant decrease in emissions per bale of cotton from seed cotton cleaning equipment when the ginning rate was increased from 4 to 10 bales/hr. This was attributed to the fact that it was not necessary to increase the air flow rate for conveying the cotton ini proportion to the increase in ginning rate. ------- TABLE 4 W TOTAL EMISSIONS ADJUSTED TO A GINNING RATE 10 BALES PER HOUR (MACHINE PICKED COTTON) EMISSIONS Hi gh* Average Source lb/hr grains/scf % lb/hr grains/scf %' Hi ah Pressure Unloading 5.41 0.211 18.1 1.14 0.038 8.4 6 cylinder cleaner and stick machine 0.14 0.002 0.5 0.06 0.001 0.4 6 cylinder cleaner 0.08 0.001 0.3 0.04 <0.001 0.3 Trash fan 0.16 0.002 0.5 0.08 0.001 0.6 Total 5.79 19.4 1.32 9.7 Low Pressure 3 No. 1 Lint Cleaners 13.92 0.036 46.4 6.98 0.017 51.8 3 No. 2 Lint Cleaners 5.62 0.032 18.7 2.08 0.012 15.4 Battery Lint Cleaner 2.10 0.010 7.0 1.33 0.007 9.8 Lint Cleaner Waste 2.55 0.011 8.5 1.80 0.008 13.3 Total 24.28 80.6 12.19 90.3 Gin Total 30.07 100.0 13.51 100.0 *Highest of 50 tests NOTE: The trash content of the machine picked cotton was 90-100 lbs/bale. ------- TABLES EMISSION RATE FROM A GIN PROCESSING MACHINE STRIPPED COTTON (ADJUSTED TO 10 BALES PER HOUR) EMISSIONS Early Season Mid Season Late Season Extremely Harvest Harvest Harvest Dirty Cotton Source Ib/hr % 1 b/hr % Ib/hr % 1 b/hr % Unloading 2.78 18.80 3.44 14.64 2.50 10.87 19.47 38.18 Total Cleaning System 2.75 18.57 4.94 21,00 7.43 32.29 10.81 21 .20 Overflow 1 .18 8.00 0.23 1 .02 0.20 0.86 3.24 6.36 Total Lint Cleaninq 8.09 54.63 14.88 63.34 12.88 55.98 17.47 34.26 Total 14.80 100.00 23.5 100.00 23.0 100.00 51 .0 100.00 Range 6.6-23.0 14.0-33.1 13.4-32.5 30.3-71 .6 Trash/Bale 447 lbs 550 lbs 501 lbs 1308 lbs ------- The studies at the USDA laboratories in Stoneville, Mississippi^ and Mesilla Park, New Mexico^ also included particle size analysis. These results are presented in Table 6 and show that the trash from stripper harvested cotton is coarser than that from picker harvested cotton. Both materials are quite coarse, how- ever, and are effectively remo_ved_W-i th high efficiencv cyclones. 3.1.2 Low Pressure Systems Emissions from the low pressure system are lint fly and small amounts of trash. This system accounts for about twice as much air as the high pressure system (Section 2.2.10). The emissions from the system comprise between 34 to 90 percent of the total gin emissions (Tables 4 and 5). With machine stripped cotton the range is from 34 to 63 percent with 55 to 63 percent being the common range. This is equivalent to a mass emission rate of 15 to 23 lb/hr at a ginning rate of 10 bales/hr^. With machine picked cotton, the low pressure system emissions comprise about 90 percent of the total gin emissions or about 12.2 lb/hr at a ginning rate of 10 bales/hr^. 3.1.3 Total Gin Emissions Several references are made to estimating emissions from cotton gins by making a material balance of materials entering the gin (seed cotton) and materials leaving the gin (lint cotton, cotton seed, green bolls, and trash). The difference in these two quan- tities, after correcting for moisture losses, has been attributed to "emissions plus other losses." ------- TABLE 6 PARTICLE SIZE DISTRIBUTION OF GIN TRASH Particle Size (microns) Percent by Weight Stripper Trash Picker Trash(9) Picker Trash^ > 3,300 67.5 49.8 420-3,300 27.2 42.3 74 - 420 4.5 5.7 < 74 0.8 2.2 > 150 96.7 50-150 0.5 25 - 50 1.1 10 - 25 1.0 5 - 10 0.3 0 - 5 0.4 Total 100.0 100.0 ------- Gins have arrived at"emissions plus other losses" of 1.9 to 8.5 percent^—Probably one of the most reliable studies of this nature was conducted at the USDA laboratory at Stoneville. Mississippi'. The unaccountable fraction in this study was 3.8 percent or 52 lbs/bale. This is very much out of line with direct measurements of emissions and indicates that this method is not sen- sitive enough to estimate emissions. 3.1.4 Other Emissions The gin trash collected by control equipment is conveyed either to a trash house or an incinerator. If the trash house is not sealed well, it can become a source of particulate emissions. Also, when transferring materials from the trash house to a truck for off- site disposal, considerable dust and lint can be released. The incineration of the trash presents an obvious potential for air pollution. No data have been published on emissions from this source. On-site composting of gin trash can result in odors or wind- blown trash, if the composting is not properly managed. Trash disposal is probably the most baffling problem facing gin operators at the present. Methods used for disposal include open burning, incineration, composting, spreading on the land, and cattle feed filler. Power requirements at cotton gins are provided by electricity, diesel, or diesel driven electric generators. Power requirements at ------- most gins only run between 300 - 600 horsepower, therefore, power generation is an insignificant source of emissions. 3.1.5 Ambient Air Quality Several ambient air quality studies have been conducted in the vicinity of cotton gins to assess the impact of this industry —-(17,12,14,15) on adjacent communities Three of the studies were con- ducted by the Texas State Health Department^—'—'—] (12) One of the Texas studiesv—' found suspended particulate 3 concentrations 300 ft. downwind from a gin to be 227,000 ug/m . The calculated emission rate from the gin was 575 lb/hr. Other results from the Texas studies showed downwind concentrations of suspended •5 particulates to range from 76,000 pg/m at a distance of 150 ft. from 3 a gin to 42 ug/m 8,000 ft. from a gin. The average concentration at a distance of 100-200 ft. from the gin was 25,000 gg/m3. At a distance of 1,200 ft. concentrations ranged from 350 - 2,100 pg/m3 It was estimated that 93 - 99 percent of the emitted particulates fall (12) out on the gin property' The benzene soluble fraction of the suspended particulates ranged from 0.5 - 3.6 percent^— O Dustfall rates ranged from 18.7 - 77.4 tons/mi /30 days, depending upon the distance from the gin^—^ (15) Studies conducted in Mississippiv—' showed concentrations of suspended particulates to range from 3,352 to 287 yg/m3, depending upon the distance from the gin and the wind speed. Concentrations ------- 3 80 - TOO ft. from, the gin ranged from 3,352 - 1638 yg/m , with wind speeds up to 9 mph. With wind speeds of 9 - 14 mph, concentrations 3 of 1,062 ug/rn were recorded 600 ft. from the gin. In the Texas studies, arsenic concentrations ranged from JL01 to HI uq/m downwind from ains. These concentrations were found 150 - 300 ft. fromi gins. The source of arsenic is the incineration of gin trash. Arsenic is used in the fields to defoliate the cotton plants before harvest. Damage to garden crops and peach and pecan trees was attributed to arsenic^^ Upwind bacteria and fungi counts in samples taken during the Texas studies were 88 to 100 and 33 to 70 per cubic meter of air, res- pectively, when collected on nutrient agar. The counts in samples taken downwind ranged front 172 to 1,752 and 19 to 129 per cubic meter of air, respectively. Blood agar bacteria and fungi counts in samples taken upwind were 82 to 87, and 24 to 26 per cubic meter of air, respectively; bacteria and fungi counts in samples taken downwind were 248 to 285, and 22 to 57 cubic meter of air, respectively. Two samples of Aerobacter aerogenes taken upwind, were negative while two taken down- wind were positive. ------- 4.0 CONTROL TECHNOLOGY Emission control methods used in the cotton ginninq industry almost entirely involve add-on cyclones or filters. Therefore, control of emissions from existing gins would not be impractical. It would involve, at most, additional duct work, the control equipment, and perhaps increased fan sizes. Control methods presently used include.: 1) Settling chambers, 2) Cyclones (large and small diameter), 3) Scrubbers, 4) Baghouses, 5) Filters, and 6) Screen wire lint cages. 4.1 Description of Equipment 4.1.1 Settling Chambers Settling chambers have been used with varying degrees of success, but are not recommended for new gins because of several inherent dis- advantages. First, the chambers must be built large enough to provide a quiescent zone at the discharge with a discharge velocity of less than 75 fpm. With the new high capacity gins the space requirements for such a structure become prohibitive. Also, the screened walls must be brushed daily to remove lint so the back-pressure does not become too great, settling chambers are a fire hazard, they are not effective for dust removal, and they must be kept dry. ------- 4.1.2 Cyclones 4.1.2.1 Large Diameter Cyclones Large diameter cyclones were used for controlling emissions from the high pressure system of cotton gins for quite some time. They have been largely replaced by the more efficient small diameter cyclone. Urge diameter cyclones are not recommended for new gins. 4.1.2.2 Small Diameter Cyclones The small diameter cyclone or the AEC cyclone as it is commonly refered to is used almost exclusively for controlling emissions from the high pressure system of cotton gins. The cyclone was developed by the Atomic Energy Commission and adapted to cotton gins. Dimensions and design criteria for this cyclone are included in several references^— Tests conducted by the USDA^—^have shown this cyclone to be 99+ percent effective for removing particulate matter from the high pres- sure system air stream. Multiple cyclone units are used with larger gas..flow volumes (>6,000 cfm) so the diameter of the cyclones can be kept below four feet. The Dressure drop across these cyclones is 4^5 inches of water. 4.1.3 Scrubbers The few scrubbers that have been used in the ginning industry consist either of a spray chamber or water injuection prior to a cyclone. They appear to serve no effective purpose. 4.1.4 Baghouses A baghouse was installed at the Valley Gin Company in Peoria, Arizona. The unit was effective for trash removal and for removal of ------- lint fly from the low pressure system. The capital cost of the installation and maintenance costs are high. Captial costs are $1.75 per cubic foot (19) per minute of airv—'. The baghouse is one possible method of controlling lint fly emis- sions from the low pressure system on new gins. 4.1.5 Filters Various types of filters have been used to control the emissions of lint fly from the low pressure system of a gin. 4.1.5.1 In-line Filter The in-line filter was developed at the USDA laboratory in Mesilla Park, New Mexico, and has been fairly effective for removing trash and lint fly. The filter is simply a wire screen set in an enlarged section of an air line. The screen is usually stainless steel and has a mesh of between 40 x 40 and 105 x 105. The 40 x 40 mesh screen is effective for machine stripped cotton and the 105 x 105 mesh screen is effective for machine picked cotton^—The design face velocity at the screen is 1000 fpm. The filters are equipped with wipers which are set to operate when the pressure differential builds to about 0.75 - 1.25 inches of water across the filter. Immediately after a wipe, the efficiency of the filters is reduced since most of the filter action is a result of the mat of lint and trash formed on the screen. ------- Tests have shown a filter with 105 x 105 mesh screen will remove 99 percent of all particles larger than 165 microns and 70 percent of particles smaller than 165 microns. The overall efficiency of the filter was 87 percent. A filter with a 70 x 70 mesh provided about the same efficiency, but emissions immediately after the screen was wiped were greater. These filters have reportedly clogged when used in high humidity locations^. Design details for these units are given in USDA publication ARS 42-103. The cost of a commercial in-line filter is in the range $1,000 - $1 ,200. 4.1.5.2 Condenser Drum Screens As an alternative to the in-line filter, the USDA laboratory at Stoneville, Mississippi has covered the condenser drum with stain- (2?) less steel wire meslr—' The standard condenser drum has a covering of perforated metal with 0.109 inch holes. The Stoneville laboratory has tried coverings with perforations ranging from 0.020 in. to 0.075 in. and has also covered the standard drum with 100 x 100 mesh screen. The following emission rates were measured: f Standard Drum Cover (0.109 in. holes) - 0.051 grains/SCF \ \ Perforated Metal (0.075 in. holes) - 0.046 grains/SCF Perforated Metal (0.033 in. holes) - 0.032 grains/SCF Perforated Metal (0.020 in. holes) - 0.027 grains/SCF 100 x 100 mesh screen over std. drum - 0.022 grains/SCF ------- This approach to emission control does increase the amount of short fibers in.the lint cotton slightly. It is inexpensive and is not affected by high humidity, however. 4.1.5.3 Other Filters The USDA Stoneville laboratory has worked on a lint filter for a battery lint cleaner which consists of a box about 8'x 8'x 8' lined with a foam filter. The air discharges through all sides of the box into the gin building. The unit is effective, but the pressure drop builds up relatively rapidly and no means of cleaning the unit during operation have been devised as of yet. 4.1.6 Lint Cages The lint cage is a cage of 14, 16, or 18 mesh wire screen which is placed over the exhaust of the low pressure system. These units have been replaced with the in-line filter or the condenser drum filter. 4.1.7 New Systems 4.1.7.1 Small Diameter Trash Systems A small-diameter-pipe trash system is described in USDA publication 42-59. This system employs a pressure blower to transport trash through a small diameter pipe rather than using a centrifugal and a large diameter pipe. This can reduce the volume of air which must be cleaned before discharge from 5,000 CFM to 600 CFM. 4.1.7.2 Monosystem Perhaps the most promising system is the Monoflow ginning system developed at the USDA Mesilla Park laboratory. This system ------- YU has only one fan exhaustinq into the atmosphere where conventional gi.ns 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 smal1-diameter cyclones and in-line,filters, reused, and finally cleaned before discharging into the outside atmosphere. The lint-conveying air from gin stands, lint cleaners, and condensers is also cleaned, washed, and returned to the inside of the gin house. With this sytem, dust and fly inside the building are prac- tically eliminated, and only clean air is discharged to the outside. 4.2 Emission Control System The wastes collected by all of the cyclones and lint filters are transported pneumatically to an incinerator or trash hopper. Figure 13 shows a typical installation. 4.3 Cost of Control Systems Costs developed in 1967 for a control system for a complete gin (23) are presented in Table 7X—. Costs estimated by the Delta Council of 14) Mississippiv—y for a gin collection system are $15,000 for a 6 bale/hr gin, and $25,500 for a 20 bale/hr gin. ------- TABLE 7 ESTIMATED COST OF TRASH-COLLECTING SYSTEM FOR 12-BALE/HR GIN(23) Three in-line filter traps-to specifications (condenser filters may be substituted for price of $1,200.00) $ 4,125.00 Six sets twin cyclones-to specifications 1 ,966j00 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. 2,674/00 Delivery and erection-trash collection system 2,600.00 Total cost trash-collecting and trash-incinerating system $12,399J00 ~ Cost does not include trash hopper or trash incinerator. * ------- TRASH CYCLONES .LINT CATCHERS L. j L.j J CONVEYOR OROPPCR- SMALL CYCLONE FAN INCINERA TOR OR LARGE TRASH HOPPER FIGURE 13 -Gin trash collection and disposal sjstcni. ------- 5.0 COTTON GINS UTILIZING THE BEST TECHNOLOGY The gins utilizing the best control technology are probably the USDA cotton qins at the Ginning Research Laboratories in Stoneville, Mississippi, and Mesilla Park, New Mexico. These gins are not typical in that they were developed for research, but they are functional. It has been at these laboratories where most of the emission control equip- ment has been developed, also. These gins employ small diameter cyclones on the entire high pressure system and in-line or condenser filters on the low pressure system. The largest gin in the U.S. was recently built for the J. G. Boswell Company of Corcoran. California. This gin is completely auto- mated and has a capacity of 40 bales/hr or 30 - 35,000 bales/season. The gin is equipped with cyclones and in-line filters. The Valley Gin Company of Peoria, Arizona has cyclones and bag filters on one of their gins. The Community Gin Company of Phoenix, Arizona utilizes cyclones with water injection. It appears that the most effective control methods now used are the small diameter cyclone and the in-line or condenser drum filter. The Monoflow system developed at the USDA Mesilla Park laboratory pro- mises to be the best overall control system. ------- 6.0 SPECIFIC REGULATIONS CURRENTLY PERTAINING TO THE COTTON INDUSTRY At present the only regulation specifically pertaining to the cotton gin industry is a section in the Texas regulations^ prohibiting the burning of wastes from cotton gin operations. General regulations are applicable to the various emissions from this industry. Incin- eration is one method of disposing of gin wastes, but since operation and regulation of incinerators have been covered elsewhere they are omitted here. 6.1 Particulate Matter Particulate matter emissions are regulated in Arizona by a process weight table (Table 8), which limits the emission rate in pounds per hour according to the weight of the material being processed in pounds per hour. Although this table is not as restrictive as that of the State of Maryland, there are currently no cotton gins in Maryland. Particulate matter emissions may result from the handling of materials. These emissions are subject to general regulations which require "reasonable" control efforts. The degree to which these general regulations are enforced would thus determine their strigency. An example of the control measures which may be required is shown in Arizona Regulations: 1. No person shall cause or permit the handling or transporting or storage of any material in a manner which allows or may allow control able particulate matter to become airborne. 2. No person shall cause or permit a building or its appurtenances, or a road, or a driveway or an open area to ------- TABLE 8 ARIZONA STATE DEPARTMENT OF HEALTH Rate of Rate of PROCESS WEIGHT RATE Emission Emission bs.hr tons/hr lb/hr 1bs/hr tons/hr 1 b/hr 100 0.05 0.551 16,000... 8.00... ., 16.500 200 0.10 0.877 18,000.. . 9.00... .. 17.900 400 0.20 1 .400 20,000... 10.00... .. 19.200 600 0.30 1.830 30,000... 15.00... .. 25.200 800 0.40 2.220 40,000... 20.00... .. 30.500 1 ,000 0.50 2.580 50,000... 25.00... .. 35.400 1 ,500 0.75 3.380 60,000.. . 30.00... .. 40.000 2,000 1.00 4.100 70,000... 35.00... .. 41,300 2,500 1 .25 4.760 80,000... 40.00... .. 42.500 3,000...,. 1.50 5.380 90,000... 45.00... .. 43.600 3,500 1.75....= 5.960 100,000... 50.00... .. 44.600 4,000 2.00 6.520 120,000... 60.00... .. 46.300 5,000 2.50 7.580 140,000... 70.00... .. 47.800 6,000 3.00 8.560 160,000... 80.00... .. 49.000 7,000 3.50 9.490 200,000... 100.00... .. 51.200 8,000 4.00 10.400 1,000,000... .. 500.00... .. 69.000 9,000 4.50 11.200 2,000,000... .. 1 ,000.00... .. 77.600 10,000 5.00 12.000 6,000,000... .. 3,000.00... .. 92.700 ------- be constructed, used, repaired or demolished without applying all such reasonable measures as may be required to prevent particulate matter from becoming airborne, including but not limited to, paving or frequent cleaning of roads, driveways and parking lots; application of dust free surfaces; appli- cation of water; and the planting and maintenance of vege- tative ground cover. 3. If reasonable measures are not taken to prevent particulate matter from becoming airborne, the Air Pollution Control Authority shall notify the owner, lessee, occupant, operator, or user, of said land that said situation is to be corrected within a specified period of time, dependent upon the scope and extent of the problem. Potential particulate emissions from burning of wastes is eliminated in Texas bv a prohibition against such burning. 6.2 Odors Of lesser concern in this industry is the problem of odors from composting gin wastes. Odors are regulated by a general nuisance clause in Texas. Several agencies outside the cotton gin belt have quantita- tive odor regulations involving dillution with odor free air. There are also guidelines in some regulations which may be used to determine if a nuisance exists such as the percent of time an odor exists. ------- 8.0 PRODUCTION AND GROWTH OF THE COTTON GINNING INDUSTRY The production and growth of the cotton ginning industry is covered in Section 1.0 of this report. In summary, the cotton production in the U.S. has remained quite steady for the past 70 years. During the last 20 years the textile market in this country has increased considerably, but the increased market has been captured by the synthetic fiber industry. The cotton percentage of the total fiber market has decreased steadily during this period. In the past two years the cotton percentage of the fiber market has leveled out and even increased slightly. Because of this and the expected continual growth in the fiber market, it is estimated that U.S. cotton production will remain at 9 - 14 million bales annually through the next 10 years. This is within current annual production fluctu- ations and can be handled with present gins. The capacity of individual cotton gins has increased considerably. It is presently estimated that a gin must process 4,000 - 10,000 bales annually to be profitable, depending upon the size of the gin. Currently, the ginning rate of gins varies from 5-20 bales/hr with an average of around 10 - 12 bales/hr. New gins are being con- structed to gin 20 - 35 bales/hr. The largest gin in the U.S. has a capacity of 40 bales/hr. Although the total industry probably will not show much growth in the near future, there is a steady move to replace smaller gins with much larger and more effective qins. This means the total number of gins in the U.S. will continue to decrease. ------- 9.0 REFERENCES 9.1 References Cited 1. Home, M.K. and Well ford, D.S., "The Economic Outlook for U.S. Cotton," presented at the National Cotton Council of America meeting, Dallas, Texas, February 1, 1971. 2. Merkel, C., Continental/Moss/Gorden Gin Company, Personal Communication, June, 1971. 3. McCaski 11» Oliver, USDA Cotton Ginning Research Laboratory, Stoneville, Mississippi, May 1, 1971. 4. Delta Council Report to the Mississippi Air and Water Pollution Control Commission, 1970. 5. Starbird, I.R., and French, B.L., "Costs of Producing Upland Cotton in The U.S., 1964-1966 Supplement," USDA Economic Research Service, Agricultural Economic Report No. 99. 6. Cotton Division, Consumer and Marketing Service, USDA, Memphis, Tennessee. 7) McCaski11, O.L., "Tests Conducted on Exhausts of Gins Handling y Machine Picked Cotton," Cotton Gin and Oil Mill Press, Sept. 5, 1970. /'v f 8; Baker, R.V., Statement to Texas Air Control Board, April 14, 1971, Austin, Texas. 9. Baker, R.V. and Stedrausky, V.L., Gin Trash Collection Efficiency of Small-Diameter Cyclones, USDA publication ARS 42-133, July, 1967. 10. Price, J.H.T., Statement to Texas Air Control Board, April 14, 1971, Austin, Texas. 11. McCaskill, O.L., "Collection Efficiency of A Gin Trash Handling System," Cotton Gin and Oil Mill Press, August 10, 1968. 12. "High Plains Cotton Gin Study," Texas State Department of Health, November 13-17, 1967. 13. "Progress Report, Air Pollution Study of Cotton Gins in Texas," Texas State Department of Health, April 15, 1965. ------- 14. "Ennis Co-op Cotton Gin Study," Texas State Department of Health, September, 1967. 15. Columbus, E.P. and McCaskill, O.L., "Air Pollution Sampling at Cotton Gins," Cotton Gin and Oil Mill Press, July 13, 1968. 16. Handbook for Cotton Ginners, USDA Agriculture Handbook No. 260, February, 1964. 17. Control of Cotton Gin Waste Emissions, Texas State Depart- ment of Health, July, 1964. 18. Wesley, R.A., McCaskill, O.L., Columbus, E.P., "A Comparison and Evaluation of Performance of Two Small- Diameter Cyclones for Collecting Cotton Gin Waste," USDA Publication ARS 42-167, January, 1970. 19. Paganini, 0., in Control and Disposal of Cotton Ginning Wastes, Public Health Service Publication No. 999-AP-31, page 50. 20. McLain, T.C., Ibid, page 71. 21. Stedrarsky, V.L., Ibid, page 48. 22. McCaskill, O.L. and Moore, V.P., "Elimination of Lint Fly, A Progress Report," Cotton Gin and Oil Mill Press, December 31 , 1966. 23. Pendleton, A.M., in Control and Disposal of Cotton Ginning Wastes, Public Health Service Publication No. 999-AP-31, page 42. 24. Texas Air Control Board, Regulation I 9.2 Associations 9.2.1 Cotton * National Cotton Council of America, Memphis, Tennessee * Cotton, Incorporated (formerly Cotton Producers Institute). 9.2.2 Cotton Ginning * National Cotton Ginners Association Box 128 Maypearl, Texas Perry Willmon, Secretary/Treasurer ------- * Texas Ginners Association 3724 Race Street Dallas, Texas * Southeastern Cotton Ginners Association Box 866 Daklonega, Georgia * Carolina Ginners Association Box 512 Bennetsville;, S. C. 9.3 Manufacturers * Continental, Moss, Gordon Gin Company Pratville, Alabama * Lumus Gin Company Columbus, Georgia * Hardwick-Etter Company Sherman, Texas 9.4 Government Agencies * USDA Cotton Ginning Research Laboratories Stoneville, Mississippi - Vernon Moore Mesilla Park, New Mexico - V. L. Stedronsky Lubback, Texas - Roy Baker Clemson, South Carolina * USDA, Cotton Division, Consumer and Marketing Service, Memphis, Tennessee * U.S. Department of Commerce, Bureau of Census ------- |