Abstract:
An apparatus and method for restoring moisture to lint cotton in a cotton gin. The moisture level of lint cotton passing from a battery condenser to a bale press, and the rate of lint cotton passing from the battery condenser to the bale press are measured, and, based on those measurements and the desired moisture level of the lint cotton at the bale press, a precise amount of water is sprayed onto the lint cotton as it passes from the battery condenser to the bale press to bring the moisture level of the lint cotton at the bale press to that desired level.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates, in general, to cotton ginning and in particular, to a method and an apparatus for restoring moisture to lint cotton in a cotton gin. 
     2. Information Disclosure Statement 
     A modern cotton gin includes several coacting subsystems that not only separates cotton seed from lint cotton, but that also dries and cleans the lint cotton and packages the lint cotton into bales for transfer to a cotton warehouse or textile mill, etc. Seed cotton (i.e., raw cotton from the cotton field) usually arrives at the cotton gin in large trailers or modules. Some type of unloading system, such as a large suction pipe or module feed system, conveys the seed cotton from the trailers or modules to the initial stages of the ginning process, typically a moisture balancing stage to either reduce or increase its moisture content to a desired level, and a rough cleaning stage to remove leaves, small trash, sticks, etc., from the seed cotton. The partially processed seed cotton is then transferred to one or more gin stands for “ginning”, i.e. for separation of the cotton seed and fiber. Each gin stand typically includes a roller gin or saw gin, etc. A typical cotton gin may have three or more gin stands. After ginning, the cotton fiber is typically referred to as “lint cotton” (sometimes referred to as “cotton lint” or just “lint”). The ginned lint may then pass through a lint cleaning stage to remove any small trash or dirt remaining in the lint. The cleaned lint is then carried through a lint flue or the like to a battery condenser, where the cleaned lint is formed into a continuous batt and discharged onto a lint slide. The batt is conveyed down the lint slide to a bale press where the batt is compressed and formed into one or more bales. Each bale may then be tied with bailing wire and wrapped with plastic, etc., before being stored or transferred to a warehouse, textile mill, etc. 
     For many years, cotton ginners have tried various methods to add moisture to lint cotton before the lint enters the bale press. Most of these prior methods add moisture at the lint slide, after the lint has left the battery condenser formed into a batt, and just prior to the batt entering the bale press. However, the accuracy of the resultant moisture level in the finished bale using these prior methods has not been universally acceptable. The typical prior method merely adds the same amount or volume of moisture to the batt, regardless of the rate at which the batt is moving down the slide (e.g., regardless of how many bales a gin stand is producing per hour, etc.), or of the preexisting moisture content of the batt. 
     A preliminary patentability search in Class 19, subclass 66C, and Class 100, subclass 74, produced the following patents, some of which may be relevant to the present invention: Buzick, U.S. Pat. No. 2,914,809, issued Dec. 1, 1959; Hurdt, U.S. Pat. No. 3,324,513, issued Jun. 13, 1967; Mangialardi et al., U.S. Pat. No. 3,392,424, issued Jul. 16, 1968; Jackson, U.S. Pat. No. 4,103,397, issued Aug. 1, 1978; Vandergriff, U.S. Pat. No. 4,140,503, issued Feb. 20, 1979; Woods, U.S. Pat. No. 4,726,096, issued Feb. 23, 1988; and Vandergriff, U.S. Pat. No. 5,381,587, issued Jan. 17, 1995. 
     None of known prior art, either singly or in combination, disclose or suggest the present invention. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention includes an apparatus and method for restoring moisture to lint cotton in a cotton gin. The concept of the present invention is to precisely adjust the moisture content of lint cotton at a lint slide based on the final moisture desired in the bale, the volume of lint cotton present (i.e., the ginning rate), and, depending on the model or mode of the present invention, the moisture present in the lint cotton before adding moisture. The present invention applies moisture to the lint cotton on the lint slide prior to entering the press. In the automatic mode of the present invention, the amount of moisture applied is determined by measuring the moisture in the lint cotton as it leaves the battery condenser (preferably using an infrared moisture measuring sensor or the like), subtracting the value of that measured incoming moisture from the desired final moisture of the finished bale, and then multiplying the difference by the rate of ginning in bales per second, resulting in the percent of moisture to be added per second to the lint cotton between the battery condenser and bale press. This data is used by the present invention to deliver a very accurately metered volume of moisture to each bale, resulting in a finished bale with the desired final moisture content, regardless of the incoming moisture or the rate of ginning. 
     The apparatus of the present invention includes, in general, rate measuring means for measuring the rate of lint cotton exiting a battery condenser; moisture adding means for adding a precise amount of moisture to the lint cotton between the battery condenser and a bale press based on the desired moisture content of the cotton bale, and the rate of lint cotton exiting the battery condenser; and, perhaps, moisture content measuring means for measuring the moisture content of the lint cotton as it leaves the battery condenser. 
     The method of the present invention includes, in general, the steps of measuring the rate of lint cotton exiting a battery condenser; adding a precise amount of moisture to the lint cotton between the battery condenser and a bale press based on the desired moisture content of the cotton bale, and the rate of lint cotton exiting the battery condenser; and, perhaps, measuring the moisture content of the lint cotton as it leaves the battery condenser. 
     One object of the present invention is to provide an accurate apparatus and method for adding a precise amount of moisture to lint cotton before the lint is tramped into a cotton bale. 
     Another object of the present invention is to provide an automatic model by adding a controlled and variable amount of moisture to lint cotton as it moves from the battery condenser down the lint slide on the way to the bale press based on, in part, the incoming moisture of the lint cotton (i.e., the moisture content of the lint cotton as it enters the lint slide, before moisture is added thereto) to result in a finished bale moisture equal to a final bale percent moisture dial setting or the like as set by gin management. 
     Another object of the present invention is to provide a manual model by adding a preset amount of moisture to each bale as the lint cotton moves down the lint slide on the way to the bale press, resulting in a finished bale that has had the percent of moisture selected on the moisture to add dial setting (set by gin management) added to the bale, regardless of the incoming moisture of the lint cotton. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 is a somewhat diagrammatic elevational view of the apparatus of the present invention, shown in combination with a battery condenser, bale press and lint slide of a cotton gin. 
     FIG. 2 is a block diagram of the apparatus of the present invention. 
     FIG. 3 is a diagram showing the arrangement of FIGS. 3A-3S. 
     FIGS. 3A-3S, taken together and arranged as shown in FIG. 3, disclose a preferred program for controlling the programmable logic controller of the apparatus of the present invention based on, for example, a three gin stand system. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A preferred embodiment of the apparatus of the present invention is shown in the drawings and identified by the numeral  11 . The apparatus  11  of the present invention is designed to restore moisture to lint cotton  13  passing from a battery condenser  15  to a bale press  17  down a lint slide  19  in a typical cotton gin. 
     The apparatus  11  includes a rate measuring means  21  for measuring the rate of lint cotton  13  exiting the battery condenser  15 , and a moisture adding means  23  for adding a precise amount of moisture to the lint cotton  13  between the battery condenser  15  and the bale press  17  based on the desired moisture content of the cotton bale B as set by gin management, etc., and the rate of lint cotton  13  exiting the battery condenser  15  as measured by the rate measuring means  21 . 
     The apparatus  11  preferably includes incoming moisture content measuring means  25  for measuring the moisture content of the lint cotton  13  as it leaves the battery condenser  15  for allowing the apparatus  11  to operate in an automatic model or mode to adding a precise amount of moisture to the lint cotton  13  between the battery condenser  15  and the bale press  17  based on the desired moisture content of the cotton bale B as set by gin management, etc., and the rate of lint cotton  13  exiting the battery condenser  15  as measured by the rate measuring means  21 , and the moisture content of the lint cotton  13  as it leaves the battery condenser  15  as measured by the incoming moisture content measuring means  25 . 
     The apparatus  11  preferably includes a programmable logic controller (PLC)  27  for monitoring and controlling the means  21 ,  23 ,  25 , etc. 
     The moisture content measuring means  25  sends a signal  28  to the PLC  27  which can be scaled by the PLC  27  to determine the moisture content of the lint cotton  13 . The moisture content measuring means  25  preferably includes an infrared (IR) sensor  29 . The IR sensor  29  is preferably a near infrared (NIR) sensor. The moisture content measuring means  25  may consist of a Moisture Register Products Smart II NIR Moisture Measuring System marketed by Moisture Register Products, a division of Aqua Measure Instrument Co., 1712 Earhart Court, La Verne, Calif. 91750-0369. 
     The rate measured by the rate measuring means  21 , typically referred to as the “ginning rate” of the gin, can be determined by several different mechanisms depending upon which is the most practical for the specific individual ginning system. 
     In a first embodiment, the rate measuring means  21  could include dual potentiometers to replace the typical speed potentiometer on the gin feeder, feed rollers controller. That is, one of the dual potentiometers will provide the feed roller speed input signal, and the other of the dual potentiometers, in conjunction with a 10 volt D.C. power supply or the like, will give an analog input (i.e., signal  30  as shown in FIG. 2) to the PLC  27  which can be scaled by the PLC  27  to determine the ginning rate of the gin stand. 
     In a second embodiment, the rate measuring means  21  could include a DC/DC transducer connected directly to the speed potentiometer of the gin feeder feed roller controller (the controller can be DC or AC invertor), with the output of the transducer (i.e., signal  30  as shown in FIG. 2) connected to the analog input on the PLC  27  so the PLC  27  can scale the analog input to determine the ginning rate. 
     In a third embodiment, a DC/DC transducer can be connected across the DC controllers armature voltage, usually denoted as Al and A 2 . The output of the transducer (i.e., signal  30  as shown in FIG. 2) is connected to the analog input on the PLC  27  so that the PLC  27  can scale the analog input to determine the ginning rate. 
     In a fourth embodiment, the rate measuring means  21  could include a DC sensor (e.g., an inductive proximity switch such as a Censtable AM series M12 DC inductive proximity switch, Model AM1-AN14A) used to count the teeth on the feeder roller shaft. By sending a DC pulse (i.e., signal  30  as shown in FIG. 2) to the PLC  27  as each tooth passes by the sensor, the speed of the lint cotton  13  exiting the battery condenser  15  can be determined by the PLC  27 . 
     The moisture adding means  23  of the apparatus  11  preferably includes a booster pump  31  coupled to an external water source  33  (e.g., a public water utility or private water system) for raising the water pressure of the water source  33  to over 50 PSI (pounds per square inch). Discharge from the booster pump  31  is connected to a ball valve  35  used to shut off the water flow when needed or desired. When the ball valve  35  is open (turned on), the pressurized water passes through a five micron filter  37  into a type B pressure regulator  39  used to control the discharge pressure to 50 PSI. A pressure gauge  41  is preferably located directly downstream of the pressure regulator  39  for displaying the controlled discharge pressure. From the pressure gauge  41 , the water passes a flow meter  43  where a DC pulse signal  45  of 182 pulses per pound of water is sent to the input module on the PLC  27 . After passing the flow meter  43 , the water enters a flow control valve  47  where the flow rate is controlled by the PLC  27  so that the desired amount of water will be discharged through the flow control valve  47 . A pressure gauge  51  is preferably located directly downstream of the flow control valve  47  for displaying the back pressure on the flow control valve  47  produced by a spray nozzle assembly  53 . The spray nozzle assembly  53  includes up to five solenoid valves  55  that are controlled by signals  57  from the PLC  27 , and a spray nozzle  59  associated with each solenoid valve  55 . The solenoid valves  55  maintain the back pressure needed to maintain a full spray pattern from each spray nozzle  59 . The apparatus  11  preferably includes five nozzles  59  aligned one behind the other above the batt (lint cotton  13 ) on the lint slide  19 , parallel to the lint slide  19 . To be certain the fan of spray leaving the nozzles  59  is of a constant width, the pressure preferably always remains at 40 pounds per square inch. Rather than pressure adjustment, nozzles  59  with orifices sizes sufficient to spray in a range of 0.1 gallon at 40 pounds per square inch to 0.5 gallon at 40 pounds per square inch, can be combined instantaneously in order to achieve the desired spray pattern. Thus, each nozzle  59  is coupled to one solenoid valve  55  to permit the nozzle combinations to change according to commands from the PLC  27 . The various components  31 ,  33 ,  35 ,  37 ,  39 ,  41 ,  43 ,  47 ,  51 ,  55  and  59  are preferably joined together in a fluid-tight manner by standard ½ inch water pipe or the like. 
     The apparatus  11  preferably includes a desired moisture control means  61  for being set by gin management, etc., to send a signal  63  to the PLC  27 , when the apparatus  11  is running in the automatic mode or model, to identify the desired final moisture content of the lint cotton  13 . The desired moisture control means  61  preferably consist of a Clarostat 53C3-10K potentiometer marketed by Clarostat Sensors and Controls, Inc., 12055 Rojas Drive, Suite K, El Paso, Tex. 79936, to allow the gin management, etc., to merely “dial in” the desired final moisture of the lint cotton  13  or cotton bale B. 
     In the fully automatic model or mode, the incoming moisture content measuring means  25  outs a 4-20 milliamp or 1-10 volt signal  28  to an analog input of the PLC  27 , as it continuously scans the discharge from the battery condenser  15 . This signal  28  to the PLC  27  is scaled by the PLC  27  to determine the presence of lint cotton  13  (used by the system to allow the water to spray) and the moisture content of the lint cotton  13  just prior to adding moisture to the lint cotton  13 . The potentiometer of the desired moisture control means  61 , in conjunction with a 10 volt DC power supply, is used to send an analog signal  63  to an analog input of the PLC  27 . This signal  63  is scaled by the PLC  27  to determine the final bale percent moisture desired in the automatic mode. 
     The apparatus  11  may include a manual added moisture control means  65  for being set by gin management, etc., to send a signal  67  to the PLC  27 , when the apparatus  11  is running in the manual mode or model, to identify the desired percent of moisture to add to the lint cotton  13 . The manual desired moisture control means  65  preferably consist of a Clarostat 53C3-10K potentiometer marketed by Clarostat Sensors and Controls, Inc., 12055 Rojas Drive, Suite K, El Paso, Tex. 79936, to allow the gin management, etc., to merely “dial in” the percent of moisture to add to the cotton lint  13 , regardless of the incoming or final moisture content of the cotton lint  13 . 
     In the manual model or mode, the potentiometer of the manual desired moisture control means  65 , in conjunction with a 10 volt power supply, is used to send an analog signal  67  to an analog input of the PLC  27 . This signal  67  is scaled by the PLC  27  to determine the percent of moisture to be added to the lint cotton  13  based on the ginning rate, regardless of the incoming or final moisture content of the cotton lint  13 . 
     The apparatus  11  may include a final moisture content measuring means  69  for measuring the moisture content of the cotton bale B after it leaves the bale press  17 . The final moisture content measuring means  69  may include a radio frequency (RF) sensor  70 . The RF sensor  70  can be mounted on the bale scales, or between the rollers  71 ′ on a roller conveyor  71 , etc. The radio frequency (RF) sensor  70  may be part of a Moisture Register Products BSP-901 RF Capacitance System marketed by Moisture Register Products, a division of Aqua Measure Instrument Co., 1712 Earhart Court, La Verne, Calif. 91750-0369. 
     The apparatus  11  preferably includes a control cabinet  72  for housing the PLC  27 , booster pump  31 , ball valve  35 , filter  37 , pressure regulator  39 , pressure gauge  41 , flow meter  43 , flow control valve  47 , automatic desired moisture control means  61 , and manual desired moisture control means  65 . The control cabinet  72  is preferably located as near as possible to the battery condenser  15 . 
     The spray nozzle assembly  53 , with the solenoid valves  55  and spray nozzles  59 , is preferably mounted over the lint slide  19  as near the battery condenser  15  as practical. 
     Once the control cabinet  72  and spray nozzle assembly  53  are in place, the solenoid valves  55  are connected to the PLC  27 , preferably via terminal strips. The external water supply or source  33  is connected to a water inlet port on the control cabinet . A water outlet port on the control cabinet  72  is connected to a water inlet port on the spray nozzle assembly  53 . An external air supply  73  with a pressure between 60 and 100 pounds per square inch is connected to an air inlet port on the control cabinet  72  and, indirectly through the control cabinet  72 , to the flow control valve  47 . The ginning rate signal  30  is carried to the control cabinet  72  by wire or transmitted over radio frequency to a receiver at the control cabinet  72 . The IR sensor  29  of the moisture content measuring means  25  should be mounted so it will be scanning the output of lint cotton  13  from the battery condenser  15  prior to the moisture being added to the lint cotton  13  via the spray nozzle assembly  53 . The incoming moisture content signal  28  is carried to the control cabinet  72  preferably by cables provided with the moisture content measuring means  25 . After this is completed, 110 volt AC power can be connected to a terminal strip of the control cabinet  72  at the PLC  27 . The apparatus  11  is then ready for operation. 
     The PLC  27  is preferably controlled by the program disclosed in FIGS. 3A-3S, taken together and arranged as shown in FIG. 3, using a signal  30  from the rate measuring means  21  (e.g., analog outputs from potentiometers, transducers or sensors as hereinabove disclosed relative to the several possible embodiments of the rate measuring means  21 ) as inputs to V2000, V2001, V2002 in the program to calculate the rate of lint cotton  13  exiting the battery condenser  15  (i.e., the ginning rate of the gin stands). The analog output or signal  63  from the automatic desired moisture control means  61  is used in the program as V2003. The analog output or signal  28  from the moisture content measuring means  25  as determined from the lint cotton  13  preferably at the discharge of the battery condenser  15  is used in the program as V2004. The program calculates the set point and stores it in V1402. The process variable is the pulses, or signals,  45  from the flow meter  43  and is stored in V1403. The PLC  27  uses the V1402 and V1403 in the internal PID loop and controls the analog 4 to 20 milliamp output (signal  49 ) which controls the flow control valve  47 . The PLC program then determines which and how many of the spray nozzles  59  should be applying moisture to the lint cotton  13 , and sends the appropriate signals  57  to the appropriate solenoid valves  55 . 
     The preferred method of the present invention includes the steps of measuring the incoming moisture content of the lint cotton  13  (in the automatic mode) between the battery condenser  15  and bale press  17  using, for example, the moisture content measuring means  25 ; measuring the rate of lint cotton  13  passing between the battery condenser  15  and the bale press  17  using, for example, the rate measuring means  21 ; and then adding a precise amount of moisture to the lint cotton between the battery condenser  15  and bale press  17  (i.e., on the lint slide  19 ) based on the desired moisture content of the cotton bale B, the moisture content of the lint cotton  13  between the battery condenser  15  and the bale press  17 , and the rate of lint cotton  13  passing between the battery condenser  13  and the bale press  17  using, for example, the moisture adding means  23  and PLC  27 . 
     As an example, assume the present invention is used with a gin having three gin stands, with one of the gin stands ginning at 10 bales of cotton per hour, another of the gin stands ginning at 12 bales of cotton per hour, and the last gin stand ginning at 8 bales of cotton per hour, resulting in a volume of 30 bales of cotton per hour (i.e., the rate measured by the rate measuring means  21 ); the moisture of the lint cotton  13  as measured by the moisture content measuring means  25 , before adding any moisture thereto, is 4%; and the desired final moisture of the finished bale is 8%. The apparatus  11  will read the rate of ginning of each gin stand every half second, add them together and divide by 3600 to obtain the ginning rate in “bales per second.” The PLC  27  will also subtract the moisture present (4% in this example) from the desired final bale moisture (8% in this example), resulting in the percent moisture to be added to the bale (4% in this example). Four percent moisture is equivalent to 20 pounds of water per bale. Therefore, in this example, the apparatus  11  will be spraying 0.1666 pounds of moisture per second (0.00833×20). The rate of ginning and amount of water needed per second is preferably recalculated every half second. The flow of water is controlled by the PLC  27 . In this example, the PLC  27  will multiply the 0.1666 pounds of water per second needed by a factor of 182 pulses per pound (the number of pulses transmitted by the flow meter 43 for each pound of water that passes through it). This results in 30.332 pulses per second needed in order to deliver the 4% moisture to the lint cotton  13 . That becomes the setpoint for the process. If the actual pulses being transmitted is above or below the setpoint, then the PLC  27  will open or close the flow control valve  47 , regulating the flow of water, until the setpoint is obtained. Note that the setpoint is recalculated each half second and has the variables (1) ginning rate, (2) moisture prior to adding moisture, and (3) final bale desired moisture. 
     When used in the automatic mode or model (using the automatic desired moisture control means  61 ), the present invention will add a controlled and variable amount of moisture to the lint cotton  13  as it moves from the battery condenser  15  down the lint slide  19  on the way to the bale press  17 , resulting in a finished bale moisture equal to the final bale percent moisture dial setting (set by gin management, etc.). 
     When used in the manual mode or model (using the manual desired moisture control means  65 ), a present amount of moisture will be added to the lint cotton, regardless of the incoming moisture, as the lint cotton  13  moves from the battery condenser  15  down the lint slide  19  on the way to the bale press  17 , resulting in a finished bale B that has had the percent of moisture set by gin management (via a moisture to add dial of the manual desired moisture control means  61 ) added to the bale B. 
     The difference in the manual and automatic modes or models is that the manual model puts in a preset fixed amount of moisture that takes into consideration the ginning rate and moisture to add dial setting, but not the moisture content before adding moisture to the lint cotton. The automatic model makes it calculations based on the ginning rate, the lint cotton moisture content prior to adding moisture, and the final percent moisture dial setting in determining how much moisture to add, and the moisture that is being added is recalculated every half second. 
     As thus constructed and used, the present invention can automatically restore moisture to the cotton lint  13  during the ginning process, using both near infrared and radio frequency sensors to deliver a very accurate moisture regardless of the incoming moisture or the rate of ginning. Advantages of the present invention include, the provision and use of incoming lint or prior bale moisture readout, final bale moisture readout to verify that the final bale moisture is correct, user defined final bale moisture, and ginning rate to determine how much moisture to add to the lint cotton  13 . Use of the present invention reduces compaction pressure required at the bale press  17  on both the tramper and the ram, increase the gin turnout (the ratio of weight of ginned lint to the weight of seed cotton), relaxes the cotton fiber, increasing the measured staple length, increases fiber strength and uniformity ratio, reduces lint fly at the bale press  17 , and results in a more uniform baled weight due to the consistent moisture. 
     Although the present invention has been described and illustrated with respect to a preferred embodiment and a preferred use therefor, it is not to be so limited since modifications and changes can be made therein which are within the full intended scope of the invention.