introduction to ginning process and types of machine.pptx

introduction to ginning process, saw and roller gin

1. Operating Cotton Ginning Machines and Control Bale Press Operations 1. Introduction to ginning Ginning mill separates cotton fiber from the seed bolls and dust particles. Depending on the capacity the Cotton Ginning Machine – it can process from about 12 bales per hour to 60 bales an hour. Prepared by Lechisa Bersisa

2. …Cont… Foreign matter levels in seed cotton before gin processing usually range from 1% to 5% for hand harvested, from 5% to 10% for spindle-harvested, 10% to 30% for stripper-harvested cottons. The level of foreign matter dictates the amount of cleaning needed Prepared by Lechisa Bersisa

3. The quality of ginned fiber is directly related to the quality of the cotton before ginning. High grades will result from cotton that comes from clean fields. Lower grades will result from cotton that comes from grassy, weedy fields in which poor defoliation or harvesting practices are used Prepared by Lechisa Bersisa …Cont…

4. Sequence of ginning machinery Feeder & pre cleaners Feeders Gin machinery operates more efficiently when the cotton flow rate is constant. The automatic feed control providing an even flow of cotton to the gin’s cleaning and drying system. Prepared by Lechisa Bersisa

5. Gin pre-cleaners machines Green ball traps The green boll trap is important for removing green bolls, rocks, and other heavy foreign matter from rough cotton. These large, heavy materials should be removed early in the ginning system to prevent damage to machinery and to preserve fiber quality. Prepared by Lechisa Bersisa

6. Principles of green ball traps Green boll traps use sudden changes in flow direction and/or reduce air velocities to separate heavy foreign materials from seed cotton Generally, removed by inertia force Prepared by Lechisa Bersisa

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8. Driers The most important factor in preserving quality during ginning is the fiber moisture content. At higher moistures, cotton fibers are stronger, but trash is harder to remove and cleaning machinery is less efficient. At low moisture, fibers are easily broken. For most conditions, cotton should be ginned at 6 to 7 percent lint moisture. Practically all of the gins are equipped with at least one stage of seed cotton drying and most ginning systems have two stages. Prepared by Lechisa Bersisa

9. …cont… The temperature of the conveying air is regulated to control the amount of drying. To prevent fiber damage, the maximum temperature in the drying system should be kept below 350 °F. Prepared by Lechisa Bersisa

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11. Cylinder Cleaners Cylinder cleaners consist of six or seven revolving spiked cylinders that turn about 400 rpm. These cylinders convey the cotton over a series of grid rods or screens, agitate the cotton, and allow fine foreign materials such as leaf trash and dirt to fall through openings for disposal. Prepared by Lechisa Bersisa

12. In many gins, two cleaners are installed in parallel with each one cleaning half the seed cotton. Principles of cylinder cleaners Cylinder cleaners break up large wads and generally get the cotton open and in good condition for additional cleaning and drying. Cylinder cleaners may also be used to remove seed cotton from the hot air line as it comes from the drier. They may be used in either a horizontal position or inclined at an angle of about 30 degrees (inclined cleaners). Prepared by Lechisa Bersisa

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14. Stick Machines The stick machine was developed to remove the extra foreign matter taken from the plant by mechanical harvesters. Stick machines use the centrifugal force created by high-speed saw cylinders to sling off foreign material while the fiber is held by the saw. Inside a stick machine, seed cotton is wiped onto the saw teeth by stationary wire brushes. Grid bars or stationary wire brushes are located around the saw cylinder to reduce the amount of seed cotton that is thrown off the cylinder. Prepared by Lechisa Bersisa

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16. Extractor-Feeders The primary function of an extractor-feeder is to feed seed cotton uniformly to the gin stand at controllable rates. Seed cotton cleaning is a secondary function. Feed rollers, located at the top of the extractor-feeder and directly under the distributor hopper, control the feed rate of seed cotton to the gin stand. These feed rollers are powered by variable-speed motors controlled manually or automatically by various interlocking systems with the gin stand. Prepared by Lechisa Bersisa

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18. Gin Stand The gin stand consists of a set of saws rotating between ginning ribs. The saw teeth pass between the ribs at the ginning point. Here the leading edge of the teeth is approximately parallel to the rib to pull the fibers from the seed rather than cutting them. The actual ginning process (separation of lint and seed) takes place in the roll box of the gin stand. Prepared by Lechisa Bersisa

19. When all the long fibers are removed, the seeds slide down the face of the ginning rib between the saws and fall onto a conveyor under the stand. Lint is removed from the saw by a rotating brush. It is then conveyed to the next machine in the ginning system, usually a lint cleaner. Prepared by Lechisa Bersisa

20. Prepared by Lechisa Bersisa Roller gin

21. Lint Cleaners Gins typically use two types of lint cleaners, air jet and saw. The air-jet lint cleaners are directly behind the gin stand and use centrifugal force to remove trash from the lint as it makes a sharp turn in the duct work. In a saw-type lint cleaner, a condenser removes the fiber from the conveying air stream and forms it into a batt . The batt is fed to a saw cylinder which normally rotates at approximately 1,000 revolutions per minute. Prepared by Lechisa Bersisa

22. Lint cleaners remove leaf particles, motes, grass, and bark that remain in cotton after seed cotton cleaning, extracting and ginning. Most gins that process machine-harvested cotton have one or more stages of lint cleaning Lint cleaning generally improves the grade classification ( colour , leaf, and smoothness) of the lint. Prepared by Lechisa Bersisa

23. Prepared by Lechisa Bersisa The most common lint cleaning sequence for roller ginned cotton A typical saw type lint cleaner which removes trash & blends & comb fibers

24. Bale Press Cotton must be baled and packaged to protect it from contamination during transportation and storage Bale coverings and ties should meet the specifications developed by the Joint Cotton Industry Bale Packaging Committee. Prepared by Lechisa Bersisa

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26. Operating Cotton Ginning Machines 1. Prepare workstation Identify and assess a ll necessary machine parts settings and preparation for machinery operation in accordance with specification and workplace standard procedures C heck Seed cotton for moisture content according to workplace procedures Record and report Non-conforming materials Kept clean a rea around the machine during setting and loading as per standard and safety procedures Prepared by Lechisa Bersisa

27. 2 . Operate cotton ginning machineries Start ginning machines in accordance with workplace standard Clean and maintain work area around machinery Stop or shut down machines in accordance with all OHS Prepared by Lechisa Bersisa

28. 3. Operate bale or mote press Start press machinery in accordance with workplace standard Monitor the feed of lint in the lint slide to the press Feed bale tie system in accordance with manufacturer procedures Clean and maintain work area around machinery Stop or shut down m achinery in accordance with all safety and workplace standard operating procedures Prepared by Lechisa Bersisa

29. 4 . Carry out operator maintenance Identify and report minor running problems in accordance with workplace and machinery manufacturer procedures Report major machinery or product faults Perform minor maintenance and cleaning in accordance with manufacturer specifications Prepared by Lechisa Bersisa

30. 5 . Dispose of waste materials Keep waste to a minimum through correct application of workplace run out procedures Recycle waste where possible Machine waste is disposed of in accordance Prepared by Lechisa Bersisa

31. 6 . Monitor product quality Identify and apply quality requirements for cotton ginning correctly for all stages of the process Monitor c otton flow to meet enterprise standard Check cotton quality visually continuously to ensure standard Recognize, isolate and report any deviations from normal Prepared by Lechisa Bersisa

32. 7 . Communicate process information Complete r ecords and other documentation clearly and accurately where required Transfer information regarding production status or problems accurately between changes in shifts Prepared by Lechisa Bersisa