Patent Publication Number: US-6713112-B1

Title: Meal cooler centrifugal separator

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation-In-Part application of U.S. patent application Ser. No. 09/659,909, filed Sep. 12, 2000 now abandoned. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a meal rendering process and apparatus. More particularly, the present invention relates to a process and apparatus that facilitates efficient recovery of particulate matter which becomes airborne as a result of a product being exposed to industrial cooling or drying processes. An example of such a cooling or drying process is during the rendering process and production of meat meal, where the meat product is heated to a temperature of approximately 270 degrees Fahrenheit The meat meal product is extruded or pressed and is placed into a counter air flow cooler which draws a counter flowing air stream over the meat meal product thereby reducing the temperature of the meat product to approximately 130 degrees Fahrenheit. However, the air stream tends to draw a significant amount of particulate meat meal away from the cooling product. The suspended product, as picked up by the air stream, may be comprised of between 10 and 15 percent fat. The present invention is directed to the use of a unique negative air pressure separator which utilizes a self evacuating centrifugal separator and water blender, which when an air stream is drawn therethrough, will recover approximately 99.9 percent of any airborne particulate from the air steam. The present invention is particularly useful for separating viscous or sticky particulate, such as the aforementioned fat particulate, from an airstream without plugging or otherwise interfering with the functioning of the separator. 
     2. Description of the Related Art 
     As mentioned above, meat meal rendering processes are known which utilize high temperature cooking to remove bacteria and to soften meat, fat, bones, skin and the like. The rendering process generally produces a soft, pliable dry product which contains approximately 10 percent moisture content. Upon completion of the rendering process the dry product will have a temperature of approximately 260° Fahrenheit (126° Celsius) and a fat content of approximately 30 percent. The cooked product is then transferred to a press such as a tapered extruder where much of the fat content is squeezed out from the meat meal product through small holes in the press. However, pressing the meat meal alone is insufficient for extracting all of the fat content from the product as about 10 to 15 percent of the fat remains in the product. 
     In prior meat rendering processes, the heated and pressed meat meal product is typically moved to a cooler where it is exposed to a stream of ambient air which is intended to cool the meat product. Ambient air in contact with the meat meal within the cooler normally increases in temperature to over 200 degrees Fahrenheit before the air exits the cooler. The heat exchange between the air stream and the product also results in moisture being drawn away from the product, with the moisture being contained in the air stream well below the dew point. The particulate which remains in the air stream as it exits the cooler may be detected by people in the form of an unpleasant odor. 
     Devices have been used in conjunction with coolers in an attempt to prevent or control particulate build up and to remove particulate content from the air stream in a controlled manner. Devices such as a conventional centrifuge or cyclone, bag houses and other types of separators have been employed using a number of configurations and methods. Unfortunately these prior devices and methods fail to separate particulate from the air stream to a desired level of efficiency and fail to address the problems associated with particulate build up. For example the oily particulate tends to build up in cyclones forming oily plugs, the rotary air lock on the discharge of cyclones likewise plug. Oily particulates also tend to buildup on the interior walls of conventional centrifuge devices causing plugging. Furthermore, the oily nature of the product renders a bag house inoperable. In addition, because the prior systems fail to separate out a sufficient percentage of particulate from the air stream, odor emitted from expelled air continues to be a problem. 
     In many rendering systems, the aforementioned problems associated with ambient air coolers are avoided by merely not using a cooler with the rendering system. In such rendering processes the hot meal product is handled directly. As a result of direct handling of the product, condensation occurs around the product thereby providing a warm moist environment for bacterial growth, such as salmonella, to occur. Obviously, in such processes odor remains a significant problem. 
     In view of the foregoing it is clear that a separator is needed having the capability to efficiently and effectively capture the particulate that is picked up in the air stream of current rendering/cooling processes. A device is needed which provides the desired particulate separation efficiency and which may be added to existing meat rendering processes. 
     BRIEF DESCRIPTION OF THE INVENTION 
     In view of the above, the present invention is directed to an apparatus and system which addresses the shortcomings of known meat meal rendering processes and associated apparatus, as generally known and described above. The present invention provides for a unique centrifugal separator and water blending chamber which may be utilized with a processing system such as the meat rendering system cooler described above or with other processing systems such as a hammer mill. In at least one embodiment of the invention, the present apparatus may be connected to a cooling system such as previously discussed by connecting the air stream outlet of the cooler to the centrifugal separator of the present invention. The centrifugal separator removes the majority of air borne particulate present in the air stream. Following the centrifugal separator, the air stream may then be directed through a separator plate and into a blender section where the air flow may be exposed or blended with water to encapsulate any particulate remaining in the air stream. The water with encapsulated particles may then be recycled through the cooler or other associated system. 
     The present invention is directed to a method and apparatus which uses a unique air stream centrifuge and water blender design which not only separates suspended particles from an air stream, but which also includes a means for removing the particles from the apparatus itself, thereby preventing buildup of separated material which could otherwise interfere with the operation of the separator. The present invention may be incorporated into existing rendering and/or cooling systems, replacing and/or supplementing prior separator mechanisms such as cyclones or bag houses. 
     The present invention is a negative pressure system which draws an air stream through a centrifugal chamber and a water blending chamber. In the centrifugal chamber a plurality of longitudinally mounted radially extending paddles rotate at high speed drawing the air stream into the chamber and forcing the air stream to circulate in a manner similar to a centrifuge. This centrifuge effect causes the majority of particulate suspended in the air stream to be separated out and to collect on the inside wall of the chamber. The circulating paddles effectively scrape the collecting particulate from the wall of the chamber preventing build up. The paddles themselves have a unique configuration which when rotating at speed provide the desired centrifugal effect upon the air stream without subjecting the air stream to disruptive turbulence. In addition, the paddles&#39; design is such that particulate tends not to collect or build up on the paddle surface. The rotating action of the paddles directs the scraped particulate matter through a gated aperture which extends the length of the chamber. The gate allows the scrapped particulate matter to be pushed out of the chamber when the gate is in the open position, thereby preventing continuous build up of particulate. 
     The scrapped particulate matter is gravity dropped from the gate and into a collection area where a trough screw advances the particulate matter to an outlet port. Initially, the particulate matter is dropped into a hopper  66 , which serves as a collection area The trough screw  70 , is proximate to the bottom of the hopper  66 , and extends beyond the hopper  66 , and into the horizontal chamber  68 , which is preferably a tube. The transition of the hopper  66 , into a tube of the horizontal chamber  68 , facilitates the formation of a cylindrical plug and air seal for the meal cooler centrifugal separator. The trough screw  70 , and the housing within which it is contained, are constructed and arranged such that the particulate matter is allowed to accumulate and form a plug which blocks air from entering the system. The plug is advanced and simultaneously maintained by the continuous build up of particulate matter behind the advancing plug. By plugging the outlet port in this manner the invention is able to maintain a negative pressure air flow without back drafting from the outside air. The matter which comprises the plug is continuously pushed to the exit and replaced by material that follows, thus assuring that no static material remains in the system. The plug system is utilized because the product is non free-flowing and is too high in fat content to work in a rotary air lock. 
     After the air stream has passed through the centrifugal chamber the air stream passes through a separator plate and into a water blending chamber or blender. The separator plate allows the air stream to pass therethrough but restricts passage of particulate thus providing for further particulate separation. Within the blender the air stream is passed through water which is injected into the blender through one or more water injection ports. The water is mixed with the air stream to encapsulate the remaining particulate in water, which is then passed out of the blender and into a collection tank. The water is mixed with the air stream with a plurality of paddles similar to those which are in the centrifugal chamber such as are described above. 
     After passing through the water blending chamber the air stream is directed onto water to encapsulate particles remaining in the air stream. The air stream is directed in this manner by a diverter plate or baffle which directs the air stream toward and/or onto the water thus encapsulating particles in the air stream which were previously wetted in the blender. Passage of the air stream over the water and particulate mixture provides an additional mixing opportunity between the water and air to separate any remaining particulate suspended in the air stream. The air stream is then pulled by a fan which releases the air stream into the atmosphere being approximately 99.9 percent or more particulate free. The water encapsulated particles may be pumped back to the cooler and injected onto the product as it passes through the cooler. Due to the high temperature of the meal product the water directed to the cooler will mostly evaporate thus depositing any particulate back into the product. This closed loop circulation of water allows the user to control and add moisture to the product as desired. 
     The present method and apparatus provides for a system which increases the efficiency of particulate collection and minimizes odor by removing most particles from the air stream. Additionally the present invention provides for a system which allows for moisture lost to a cooling, drying or other process to be replaced by recirculating moisture through a closed loop system for return to the original product during processing. 
     The present invention may be embodied in a variety of unique systems and apparatus such as those described in detail below. The invention may be retrofitted to an existing meal processor or may be included in new processor designs as well. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     A detailed description of the invention is hereafter described with specific reference being made to the drawings in which: 
     FIG. 1 is a diagrammatic representation of a prior art particulate retrieval system; 
     FIG. 2 is a diagrammatic representation of an embodiment of the inventive process viewed in association with a counter air-flow cooling system; 
     FIG. 3 is a partially cut-away perspective view of an embodiment of the apparatus; 
     FIG. 4 is a cut-away side view of the embodiment shown in FIG. 3; 
     FIG. 5 is an exposed end view of an embodiment of the invention; 
     FIG. 6 is a detail perspective view of one embodiment of the paddles utilized by the present invention; 
     FIG. 7 is a cut-away detailed side view of a portion of the invention shown in FIG. 2, illustrating the operation of a trough screw and advancing plug; and 
     FIG. 8 is a diagrammatic view of an embodiment of the present invention as may be utilized with a hammer mill. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As indicated above the present invention is directed to an apparatus for separating particles from an air stream. The air stream may be the air stream derived from a cooler, a rendering system, a hammer mill, a dryer, or any other type of processing system where particulate matter may be picked up by an air stream. 
     In accordance with the present invention, the preferred embodiments described herein are capable of recovering about 99.9% or more of the particulate that are captured by the air stream, even where the particulate matter at issue is viscous, sticky, oily or otherwise difficult to separate and collect. 
     FIG. 1, illustrates one embodiment of a prior art meat meal rendering and cooling system  100  used to capture particulate trapped in an air stream. As may be seen, the system  100  utilizes a cyclone or other capture device  102  in association with a counter air flow meat meal cooler  22 . In the process shown, an air stream  106  is passed over a meal product which causes particulate  104  to become suspended therein. In order to filter the particulate  104  out of the air stream  106 , so as to reduce air borne odor, the air stream is run through the cyclone  102 . In a meat rendering process, the particulate  104  suspended in the air stream  106  tends to be extremely oily due to a relatively high content of fat. The fat content plus the extreme heat of the meal product makes it difficult to separate particulate  104  from the air stream  106 . A cyclone  102  may be used to perform particulate capture functions from an air stream having between ten to twelve percent fat content but even in an air stream having the aforementioned fat percentages, the cyclones  102  do not remove sufficient quantities of the particulate  104 . In addition, cyclones  102  will not properly function where fat content is greater than approximately 12 percent. Due to the oily, viscous nature of the fat particulate and because such prior art systems are not self evacuating or self-cleaning as the present invention is, cyclones  102  tend to plug from the particulate  104  which builds up therewithin, thereby rendering the cyclone  102  as well as the entire system  100  inoperable. 
     Normally, 10% to 15% of the cooled product  21  is captured by the cooling air stream  106  and exits the cooling system  22  as trapped particles  104 . In the prior art system shown, the particulate matter which is captured in such a system may be discharged at the bottom of the cyclone  102  where it may be packaged or dealt with as desired. An example of such a particulate capture system which employs a cyclone is disclosed in U.S. patent application Ser. No. 09/303,871 entitled PARTICULATE CAPTURE SYSTEM AND METHOD OF USE, filed May 3, 1999, the entire contents of which being incorporated herein by reference. 
     Turning to FIG. 2, a modern particulate capture system  10 , is shown which employs an embodiment of the particulate separator  12  of the present invention. The particulate separator  12  is in functional communication with a closed cooler system  22  and replaces the cyclones and/or separators  102  of the prior art system  100  shown in FIG. 1 The particulate separator  12  of the present invention includes a unique centrifugal separator  14  and a specialize high speed blender or agitator  16  which are utilized in a unique arrangement so as to initially separate out the majority of the particles  104  from the air stream  106  and then encapsulate any remaining particulate  104  of the air stream  106  in water  18  that is subsequently reprocessed to capture nearly 100% of the particulate. 
     As is known, many current rendering processes include a cooking process to soften the meal which is subsequently passed through an extruder or press  20  such as may be seen in the system  10  shown in FIG.  2 . As previously discussed however, it should be noted that the present invention may be utilized with a variety of processes of which many do not include a press or even a necessarily rendered product. In the prior art embodiment shown in FIG. 1, the press separates approximately 85% to 90% of the fat portion of the meal, the remaining portion of the meal product  21  being transported to the closed cooler system  22 . Cooler systems such as the one presently shown may be a counter flow cooler such as a Scott Cooler System manufactured by Scott Equipment Company of New Prague, Minn. In the present context the term cooler may also include any of a variety of apparatus such as concurrent air flow driers or other devices which pass an air stream over a product. 
     In the present embodiment shown in FIG. 2, the cooler system  22  employs a stream of ambient air in combination with water that is injected on to the product  21 . The injected water  18  provides the invention with the enhanced cooling benefits while simultaneously increasing the moisture content of the meal product  21  to a desired level. In an embodiment directed to a meat rendering process, the cooked meat meal product  21  leaving the press  20  is quite dry, having only about 2½% to 3% moisture content. Generally, this cooked meat meal product  21  also exits the press  20  at a temperature of about 260 degrees Fahrenheit and having a fat portion consisting of about 10% to 15% of the total rendered product. 
     It may be seen that the cooked dry product enters the cooler system  22  at a product entry port  24  near one end while the air stream  106  enters the cooler system  22  through an air entry port  28  located at the opposite end of the cooler system  22 . As the cool air  106  is pulled through the cooler system  22 , it passes over the cooked product  21  that is moving in the opposite direction to produce a counter flow condition between the cooling air  106  and the cooked product  21 . During this counter flow condition, particulate  104  (which may include a significant portion of fat) within the cooked product  21  are undesirably mixed with the cooling air  106  which exits the cooling system  22 . 
     The general function of the present separator  12  may best be understood when viewed in the context of the process  10  shown in FIG.  2 . It can be seen that after the air stream  106  passes over the product  21 , the air stream  106  enters the present separator  12  at an inlet port  32 . A more detailed explanation of the present particulate capture system  10  and the associated particulate separator  12  will be described herein below with reference to FIGS. 3-6. 
     Generally, the air stream  106  is drawn into the air chamber  34  via the air inlet port  32 . The air stream  106  is drawn into the chamber  34  as a result of the negative pressure supplied by the fan  49  and the high speed rotation of a plurality of air paddles  36  and  72  which are mounted to a longitudinally oriented drive shaft or axle  76 . As is clear from the embodiments shown in FIGS. 3-6, the drive shaft  76  extends entirely through the air centrifuge separator or section  14  as well as the blender section  16 . As may also be seen in FIGS. 3 and 4, paddles  36  are located within the centrifuge separator or section  14  and paddles  72  are positioned within the blender  16 . Due to the relative size of the chamber  34  within the centrifuge  14  and the blender  16 , the air paddles  36  are longer than air paddles  72 . 
     In an alternative embodiment, the centrifuge  14  may be adjacent to and separated from the blender  16 . In this embodiment, a first drive shaft or axle  76  may traverse the centrifuge  14  and a second drive shaft or axle  76 . 1  may traverse the blender  16 . Each of the first and second drive shafts  76  and  76 . 1  respectively may be engaged to an independent motor, engine, and/or rotational mechanism  35  which may be coupled to impart rotational motion through pulleys, gears, or other rotational means. In this embodiment, bushings and/or bearings are preferably positioned for support and engagement to the respective drive shaft  76 ,  76 . 1  to facilitate rotation within each of the centrifuge  14  and/or blender  16 . The rotation of each drive shaft  76  and  76 . 1  is therefore not required to be synchronized and/or identical in speed between the centrifuge  14  and/or blender  16 . Each of the separator  14  and/or blender  16  is required to include an opening  76 . 2  to permit air passage therebetween. The opening  76 . 2  may be the same size or a different size than the separator plate  74  to provide restrictive or less restrictive air flow. A channel and/or air passage may also extend between the centrifuge  14  and blender  16  to provide air flow communication via the opening  76 . 2 . Preferably the channel and/or air passage between the centrifuge  14  and blender  16  has a short longitudinal dimension to minimize clogging therein. The centrifuge  14  and/or blender  16  are also preferably positioned in as close of a proximity to each other as possible without creating interference between the bearings, bushings, and/or rotation of the first drive shaft  76  relative to the second drive shaft  76 . 1 . In this embodiment, the opening  76 . 2  and the air channel/passage may be preferably positioned towards the upper end walls of each of the centrifuge  14  and/or blender  16  opposite to the aperture  41 . The positioning of the air channel/passage upwardly away from the aperture  41  preferably minimizes risk of clogging with air born particulate  104 . The air passage/channel extending between the centrifuge  14  and/or blender  16  may also include quick release coupling mechanisms to facilitate disassembly and cleaning and/or replacement as desired by an individual. The separation of the centrifuge  14  and the blender  16  preferably reduces risk of shaft deflection which may occur during rotation at certain speeds which may vary dependent upon the length of the shaft. For example, when a longitudinal dimension of the centrifuge  14  and blender  16  increases, it is preferable to incorporate a dual drive shaft  76 ,  76 . 1  embodiment to reduce shaft deflection especially during rotation at increased speeds. 
     As may best be seen in FIG. 4, the paddles  36  and  72  of the present invention may be seen to have a unique construction. The paddles  36  and  72  are designed to scrape and to prevent particulate material  104  from collecting in the chamber  34 . An additional property of the paddles  36  is that the paddle faces  80 , (which are the sides of the paddles which actively push against the air during rotation) have a fairly narrow width  82 . The paddles  36  may be between ¼ of an inch to over 2 inches in width. In the embodiment shown the paddle faces  80  have a width of ½ an inch. In at least one embodiment, as shown in FIG. 6, the paddles faces  80 , of the paddles  36  are angled between substantially 10° and 25° degrees relative to the support shaft  84  which connects the paddle face  80  to the drive shaft  76 . In the case of the centrifuge  14 , the angled paddle face provides the paddles  36  with increased ability to push particulate  104  into the aperture  41 . The paddles  72  within the blender  16  may be configured to have faces  80  which are angled in any manner desired by the user. In the embodiment shown, the faces  80  are angled relative to the support shafts  84  in the same manner as the paddles  36  in the centrifuge  14 , though such an arrangement is not required in the blender  16 . 
     In the embodiment shown the paddles  36  and  72  are arranged about the shaft  76  or  76 . 1  in an opposingly offset manner as shown. The offset arrangement of the paddles  36  or  72  have been found to provide improved air flow and rotational balance as the shaft  76  or  76 . 1  is rotated. In alternative embodiments paddles  36  or  72  may be arranged in any manner desired by the user. A detailed description of alternative rotatable air paddles (hammers/beaters) which may be adapted for use with the present particulate separator  12  is presented in U.S. Pat. No. 5,887,808, entitled High Efficiency Grinding Apparatus, issued Mar. 30, 1999 to Richard V. Lucas. U.S. Pat. No. 5,570,517, entitled Slurry Dryer, issued Nov. 5, 1996, to William A. Luker, assigned to the same assignee as the present invention, also describes paddles or blades on a rotating shaft which may be modified for inclusion in the present invention. Both references are incorporated by reference herein in their entirety. 
     As may be seen in FIG. 5 drive motor  35  rotates the drive shaft  76  or  76 . 1 , and therefore the air paddles  36  and  72 , at a rotational rate between approximately 400 and 2300 rpm. The drive motor  35  may be any type of drive mechanism known and may engage the drive shaft  76  or  76 . 1  by belt, chain, hydraulic or other means. The rotating action of the paddles  36  within the centrifuge  14  forces the particulate  104  of the air stream  106  radially outward causing the majority of the particulate  104  to collect on the inside wall  31  of the centrifuge  14 . 
     In FIGS. 2-4, it may be seen that the centrifuge  14  may be characterized in general as a substantially hollow, cylindrical shaped structure. The centrifuge  14  includes an air inlet port  32  which is where the air stream  106  enters the chamber  34 . Extending the length of the centrifuge  14 , the inside wall  31  has an aperture  41 . The aperture  41  may be covered by a curved gate  58  (not visible in FIG. 2, see FIGS. 3 and 5) which is shaped to follow the contour of the curve of the inside wall  31  of the centrifuge  14 . 
     During operation, the drive shaft  76  spins the paddles  36  so as to create a radially acting force on the air stream  106 . This force causes a significant portion of the particulate  104  to be separated from the air stream  106 . If the particulate is not sticky or viscous, the particulate will be directed into the aperture  41  as a result of the radially acting force. If the particulate  104  sticks to the inside wall  31  of the centrifuge  14 , which is often the case, the paddles  36  are of sufficient length to “scrape” any accumulating particulate matter off of the inside wall  31  and into the aperture  41 . Where the particulate  104  is particularly sticky, the aperture  41  may begin to clog. To prevent this, the gate  58 , as shown in FIGS. 3 and 5 may by closed at predetermined times to allow the paddles  36  to contact and scrape any accumulation of particulate matter off of the gate  58 . The gate  58  is once again opened to allow the particulate  104  to be directed for passage into the aperture  41 . The opening and closing of the gate  58  may be done manually by actuation of a lever  60 . Alternatively the gate  58  may be opened and closed by hydraulic or electronic actuators, or a series of mechanical linkages  61  as may be desired. Such an actuator may also be controlled by a timing mechanism for periodic opening and closing of the gate  58 . 
     As may be seen in FIG.  2  and in FIG. 7, the collected matter which passes through the aperture  41 , falls into a collector  66 . The collector  66  includes substantially horizontal chamber  68  which contains a trough screw  70 . As the particulate matter  64  is deposited into the collector  66 , the trough screw  70  continuously draws the matter into and through the chamber  68 . As may be seen however, the trough screw  70  has a length which is shorter than the length of the chamber  68 . The difference in lengths between the trough screw  70  and the chamber  68  allows matter to accumulate and form a solid plug  73  of continuously advancing matter. The motion of the trough screw  70  continues to provide new matter to the plug  73  thereby continuously pushing the plug  73  out of the chamber  68  where it may be continuously fed into a storage vessel or other apparatus. The plug material  73  may also be directed to a conveyor or other apparatus which will recombine the plug material with the original product  21 , as may be seen in FIG. 2, as desired by the user. The trough transitions into a tube and/or horizontal chamber  68  upon exit from the collector  66 , to facilitate the formation of a cylindrical plug of material which, in turn, functions as an air seal. 
     The formation of a plug  73  functions as an air lock to prevent reverse air passage into the blender section  16  and/or the centrifuge section  14 , such as are shown in FIG.  2 . The plug  73  of material ensures that air, other than the air stream  106  drawn in through the inlet port  32 , is prevented from entering the system. This allows a negative pressure to be maintained within the chamber  34  which ensures that air stream  106  is properly drawn through the entire separator  12  for maximum particulate removal. 
     With reference to FIGS. 2 it may be seen that after passing through the centrifuge section  14  of the chamber  34 , the air stream  106  is drawn into the blender section  16 . A separator plate  74  is positioned between the blender  16  and the centrifuge  14 . The separator plate  74  substantially restricts the chamber  34  by providing a circular plate which substantially blocks the passage between the centrifuge  14  and the blender  16  but which has one or more openings  77  to allow the air stream  106  to pass therethrough. The separator plate  74  reduces the opening between the centrifuge  14  and the blender  16  by one to two inches or more relative to the diameter of the smaller blender section  16  as shown. By restricting the passage between the centrifuge  14  and blender  16 , the separator plate  74  ensures that larger particulate  104  and collected particulate matter are prevented from entering into the blender  16 . 
     After passing through the centrifuge  12  and separator plate  74 , the air stream  106  is substantially particulate free. Once the air stream  106  has entered the blender  16 , one or more water injection nozzles  78  may inject water  18  into the blender  16 . The paddles  72  of the blender section  16  mix the air stream and water together, thereby encapsulating most, if not all, of the remaining particulate  104  in water. The blender  16  may also include one or more regularly spaced weir plates  45  to further restrict air passage for exposure to water. The blender  16  preferably includes fluid removal passages to which permit fluid flow past the weir plates for inclusion within the closed water system. The water  18  passing through the injection nozzles  78  and into the blender  16  may also be treated with a deodorizing agent such as chlorine, detergents, perfumes, and/or any other mixed liquid odor masking agent which may be safe for consumption by animals. The introduction of an odor masking and/or deodorizing agent preferably further reduces the odors which are inherent in the air stream and air particulate  104  which passes below the director plate  52  for discharge into the atmosphere. The masking and/or deodorizing liquid introduced into the blender  16  may also be collected within the muddy water  46  and storage tank  48  to reduce and/or mask odor therein. The deodorizing liquid may then be recycled into the closed loop water system for pumping to the cooler  22  to reduce the undesirable odors associated with the hot meat meal as cooled within the cooler  22 . 
     Water encapsulated particles or “muddy water”  46  exit the blender  16  at end  42  through a water discharge port  44 . Muddy water  46  is preferably released into a liquid storage tank  48 . Meanwhile the air stream  106  is directed out of the blender  16  through a discharge port  50  and is directed into the storage tank  48 . A baffle or director plate  52  restricts the air flow to ensure that the air stream  106  passes over the surface of the muddy water  46  stored in the tank  48 . The director plate  52  may be manually and/or mechanically raised or lowered relative to the surface of the muddy water  46  within the storage tank  48 . Manual adjustment means may include adjustable levers having a plurality of positioning stops and/or rotatable hand wheels connected to screws and/or gears. Alternatively, the director plate  52  may be adjustably raised and/or lowered relative to the surface of the muddy water  46  via an electronic motor at the discretion of an individual. The adjustment of the height of the director plate  52  relative to the surface of the muddy water  46  may therefore be utilized to regulate air flow passage and the contact of airborne particulate  104  exiting the blender  16  for contact with the exposed surface of the muddy water  46 . It should be noted that the director plate  52  may be lowered and/or raised dependent upon the elevation of the muddy water  46  within the tank  48  so long as an air flow communication passage remains open. The passage of the air flow into/over the muddy water  46  allows for an additional interface for encapsulating any particulate  104  which may be suspended in the air stream. After passing through the tank  48  the air stream is substantially free from suspended particulates  104  and may be released into the atmosphere via fan  49 . 
     The muddy water  46 , may be recirculated back into the system  10  by pumping or otherwise transporting the muddy water  46  back to the cooler  22 . Alternatively, the muddy water  46  may be passed to a drain and/or sewer pipe for disposal at the preference of an individual. 
     In at least one embodiment, a diaphragm pump  53  and water pipe  54  may be used to transport the muddy water  46  back to the cooling system  22 , where the muddy water  46  is injected into the cooling system  22  near the dry product entry port  24  such that it may be mixed with the bulk hot dry product  21  during the cooling process. 
     The present inventor has found the present embodiment useful in removing odor from the air stream that is optionally and subsequently released to the atmosphere. Since the air stream has already been cleaned via the centrifuge  14  and blender  16 , in the particulate capture system  12 , little, if any residue is left in the air stream. 
     Due to its high efficiency, it has been found that the novel particulate separator  12  of the present invention will produce the desired results without necessitating the need for a cyclone  102  (as seen in FIG.  1 ). Therefore, a more preferred embodiment of a process  10  for recapturing particulate, e.g. fat laden particulate, eliminates the cyclone  102  such that the cooling system  22  may be coupled directly to the present particulate separator  12  via the aforesaid inlet port  32 . 
     In the embodiment shown in FIG. 8, the separator  12  may be seen in use with a hammer mill  90 . In this embodiment the separator  12  may be used in association with a hammer mill, to provide an air flow assist which will draw air borne particles  94  out of and through the mill screen  92 . The air borne particles  94  may then be processed by the centrifuge  14  and blender  16  in the manner described above. In such an embodiment, it may be desirable to forego the use of recirculated water in the blender  16 . If this is desired, the water  18  from the blender  16  may be disposed of rather than recirculated. Alternatively the use of the blender  16  may be omitted at the preference of a user. 
     Test results have shown that the disclosed particulate capture system  10  successfully removes 99.9997% of air borne particulate  104  when no water is added and 99.99992% when water is added through the water injection nozzle  78 . 
     The testing was conducted by Mostardi-Platt Associates, Inc., (Mostardi Platt) which performed a particulate emissions engineering test on the particulate capture system  10  at the New Prague, Minn. plant of Scott Equipment Company. 
     The purpose of this test was to quantify emissions of Total Suspended Particulate (TSP)  104  matter during two different operating conditions. During the first test, a “dry” product was fed through the system. During the second test, water was added to the system. 
     The results of this test program are summarized in Table 1. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 No Water Added 
                 Water Added 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                   
                 Filterable TSP 
                 0.811 lb/hr 
                 0.170 lb/hr 
               
               
                   
                 Aqueous Condensible TSP 
                 0.061 lb/hr 
                 0.045 lb/hr 
               
               
                   
                 Organic Condensible TSP 
                 0.012 lb/hr 
                 0.012 lb/hr 
               
               
                   
                 Total TSP 
                 0.854 lb/hr 
                 0.227 lb/hr 
               
               
                   
                   
               
            
           
         
       
     
     The unit operating data recorded during the test are presented in Table 3. 
     Visible amounts of particulate matter  104  were observed on the filters from both test runs. This particulate matter  104  could be characterized as two distinct types, differing in color and size. One type was a relatively light brown in color, and fairly fine (small and symmetrical in size). The other type was a relatively dark brown in color, and coarse (large and irregular in size). 
     The dark brown particulate matter was material that had previously accumulated on the inside of the system exhaust stack and was blown off the stack walls during the test. The light brown particulate matter represented emissions from the dryer/separator process during the test. It appeared that there was relatively more of the dark brown matter present on the filter for the first test run than for the second. 
     All testing, sampling, analytical, and calibration procedures used for this test program were performed as described in the Title  40 ,  Code of Federal Regulations, Part  60 (40 C.F.R. 60), Appendix A, Methods 1 through 5; and 40 C.F.R. 51, Appendix M, Methods 102A and 202 and the latest revisions thereof Where applicable, the  Quality Assurance Handbook for Air Pollution Measurement Systems,  Volume III, Stationary Source Specific Methods, United States Environmental Protection Agency (USEPA) 600/4-77-027b was used to determine the precise procedures. 
     Moisture was determined in accordance with Method 4, 40 C.F.R. 60. 
     During the test 100 grams of water were added to each of the first two impingers and the third was left empty. An impinger containing approximately 150 grams of silica gel was attached following the third impinger. The entire impinger train, excluding the inlet and outlet connectors, was weighted to the nearest 0.5 gram. The impingers were placed in an ice bath to maintain the temperature of the gas passed through the silica gel impinger below 68° F. Samples were collected concurrently with, and as an integral part of Method 5 sampling. 
     After each test run, a leak check of the sample train was performed at a vacuum greater than the sampling vacuum to determine if any leakage had occurred during sampling. Following the leak check, the impingers were removed from the ice bath and allowed to warm. Any condensed moisture on the exterior was removed and the train re-weighed. 
     A single test point, located in the center of the exhaust duct was utilized. 
     The particulate sample train was manufactured by Nutech Corporation of Durham, N.C. and meets all specifications required by Method 5, 40 C.F.R. 60. A glass-lined probe was used. Velocity pressures were determined simultaneously during sampling with a calibrated S-type pitot tube and inclined manometer. All temperatures were measured using K-type thermocouples with calibrated digital temperature indicators. 
     The filter media were Whatman 934-AH glass micro-fiber filters exhibiting a ≧99.97% efficiency on 0.3 micron DOP smoke particles in accordance with ASTM Standard Method D-2986-71. All sample contact surfaces of the train were washed with HPLC reagent-grade acetone. These washes were placed in sealed and marked containers for analysis. 
     Sample recovery was performed in the Mostardi-Platt Eagan, Minn. office by the test crew. All final particulate sample analyses were performed at the Braun Intertec Corporation laboratory in Bloomington, Minn. 
     The test method applies to the determination of the condensible particulate matter (CPM) emissions from stationary sources. It is intended to represent condensible matter as material that condenses after passing through a filter and as measured by this method. (Note: The filter catch was analyzed according to Method 5, 40 C.F.R. 60&lt;procedures.) 
     The CPM is collected in the impinger portion of Method 5 type sampling train. If applicable, the impinger contents are immediately purged after the run with nitrogen (N 2 ) to remove dissolved sulfur dioxide (SO 2 ) gases from the impinger contents. The impinger solution is then extracted with methylene chloride (MeCl 2 ). The organic and aqueous fractions are then taken to dryness and the residues weighed. A correction is made for any ammonia present due to laboratory analysis procedures. The total of both fractions represents the CPM. 
     Dry and wet test meters were calibrated according to methods described in the Quality Assurance Handbook, Sections 3.3.2, 3.4.2 and 3.5.2. Percent error for the wet test meter according to the methods was less than the allowable error of 1.0 percent. The dry test meters measured the test sample volumes to within 2 percent at the flow rate and conditions encountered during sampling. 
     The individual run results for the particulate capture system are shown in Table 2. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 TEST RESULTS SUMMARY 
               
               
                 Individual Run Results - Pilot Dryer/Separator 
               
            
           
           
               
               
               
            
               
                   
                 Run 1 
                 Run 2 
               
               
                   
                   
               
            
           
           
               
               
               
               
            
               
                   
                 Test Date: 
                 10/20/2000 
                 10/20/2000 
               
               
                   
                 Sample Period: 
                 10:42-12:42 
                 13:50-16:00 
               
               
                   
                 Total Sampling Time (min): 
                 120 
                 130 
               
               
                   
                 PROCESS CONDITIONS 
               
               
                   
                 Average Duct Temperature (° F.): 
                 181 
                 130 
               
               
                   
                 Average Duct Velocity (ft/s): 
                 36.6 
                 36.05 
               
               
                   
                 Duct Moisture Content (% vol.): 
                 1.7 
                 4.6 
               
               
                   
                 Duct O 2  Content (% vol. dry): 
                 15.2 
                 15.4 
               
               
                   
                 Duct CO 2  Content (% vol. dry): 
                 5.3 
                 5.2 
               
               
                   
                 Wet Mole Weight (g · gmole): 
                 29.26 
                 28.92 
               
               
                   
                 Volume Flow Rate (ACFM): 
                 2344 
                 2313 
               
               
                   
                 Volume Flow Rate (SCFM): 
                 1932 
                 2069 
               
               
                   
                 Volume Flow Rate (DSCFM): 
                 1898 
                 1974 
               
               
                   
                 Product Feed Rate (lb/hr): 
                 2940 
                 2900 
               
               
                   
                 Moisture Added: 
                 No 
                 Yes 
               
               
                   
                 Natural Gas to Dryer (cu. ft/sec): 
                 0.093 
                 0.119 
               
               
                   
                 SAMPLE DATA 
               
               
                   
                 Sample Volume (dscf): 
                 62.764 
                 73.027 
               
               
                   
                 TSP Collected (mg) 
               
               
                   
                 Filterable: 
                 202.7 
                 47.6 
               
               
                   
                 Aqueous Condensible: 
                 15.3 
                 12.5 
               
               
                   
                 Organic Condensible: 
                 3.1 
                 3.4 
               
               
                   
                 Total: 
                 221.1 
                 63.5 
               
               
                   
                 TSP Concentration (gr/dscf) 
               
               
                   
                 Filterable: 
                 0.0498 
                 0.0101 
               
               
                   
                 Aqueous Condensible: 
                 0.0038 
                 0.0026 
               
               
                   
                 Organic Condensible: 
                 0.0008 
                 0.0007 
               
               
                   
                 Total: 
                 0.0544 
                 0.0134 
               
               
                   
                 TSP Emission Rate (lb/hr) 
               
               
                   
                 Filterable: 
                 0.811 
                 0.170 
               
               
                   
                 Aqueous Condensible: 
                 0.061 
                 0.045 
               
               
                   
                 Organic Condensible: 
                 0.012 
                 0.012 
               
               
                   
                 Total: 
                 0.884 
                 0.227 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
               
               
             
               
                 TABLE 3 
               
               
                   
               
               
                 MATERIAL 
                   
                   
                   
                   
               
               
                 FORMULAS, 
                 NO 
                 NO 
                 WATER 
                 WATER 
               
               
                 ETC: 
                 WATER 
                 WATER 
                 ADDED 
                 ADDED 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 RUN #: 
                 START 
                 1 − T = 
                 1 − T = 
                 2 − T = 
                 2 − T = 
               
               
                   
                 UP 
                 30 
                 110 
                 30 
                 105 
               
               
                 HZ/RPM&#39;S: 
                 47 Hz 
                 47 Hz 
                 47 Hz 
                 47 Hz 
                 47 Hz 
               
               
                   
                 1800 
                 1800 
                 1800 
                 1800 
                 1800 
               
               
                 HP/VOLTS: 
                 10/230 
                 10/230 
                 10/230 
                 10/230 
                 10/230 
               
               
                 NL AMPS : 
                 10.5 
                 8.0 
                 8.0 
                 10.1 
                 10.1 
               
               
                 LOAD 
                 — 
                 10.5 
                 10.0 
                 18.0 
                 10.5 
               
               
                 AMPS: 
               
               
                 FEEDER 
                 MIXER- 
                 MIXER- 
                 MIXER- 
                 MIXER- 
                 MIXER- 
               
               
                 TYPE: 
                 FEEDER 
                 FEEDER 
                 FEEDER 
                 FEEDER 
                 FEEDER 
               
               
                 FEEDER 
                 — 
                 32 Hz 
                 32 Hz 
                 32 Hz 
                 32 Hz 
               
               
                 SPEED 
               
               
                 HZ/ 
               
               
                 REEVES: 
               
               
                 NOTES: 
                 ROTOR 
                 — 
                 ROTOR 
                 ROTOR 
                 ROTOR 
               
               
                   
                 60 Hz 
                   
                 60 Hz 
                 60 Hz 
                 60 Hz 
               
               
                 NOTES: 
                 — 
                 — 
                 50% Full 
                 75% Full 
                 60% Full 
               
               
                   
                   
                   
                 15.0 amp 
                 11.9 
                 10.4 
               
               
                   
                   
                   
                 ½ the 
                 amps 
                 amps 
               
               
                   
                   
                   
                 paddles on 
               
               
                 LBS/HR: 
                 — 
                 2940 
                 — 
                 2900 
                 2900 
               
               
                 FEED ° F.: 
                 Ambient 
                 Ambient 
                 175.0° F. 
                 179° F. 
                 215° F. 
               
               
                   
                   
                   
                 recycled 
               
               
                   
                   
                   
                 product 
               
               
                 MOISTURE 
                 10.3% 
                 10.3% 
                 5.2% 
                 Water 
                 1.1 gpm 
               
               
                 IN: 
                   
                   
                   
                 out 1.2 
               
               
                   
                   
                   
                   
                 gpm 
               
               
                 MOISTURE 
                 — 
                 5.2% 
                 3.4% 
                 — 
                 — 
               
               
                 OUT: 
               
               
                 PRODUCT 
                 — 
                 181° F 
                 1620° F. 
                 210° F. 
                 235° F. 
               
               
                 ° F.: 
               
               
                 AIR IN 
                 270° 
                 500° F. 
                 360° F. 
                 400° F. 
                 405° F. 
               
               
                 ° F.: 
               
               
                 AIR OUT 
                 215° F. 
                 205° F. 
                 215° F. 
                 245° F. 
                 265° F. 
               
               
                 ° F.: 
               
               
                 PITOT 
                 159° F. 
                 158° F. 
                 167° F. 
                 105° F. 
                 111° F. 
               
               
                 ° F.: 
               
               
                 PITOT P: 
                 1.10 
                 1.10 
                 1.10 
                 1.15 
                 1.15 
               
               
                 DRYER P: 
                 6.0 
                 8.0 
                 8.0 
                 7.5 
                 5.5 
               
               
                 COLLEC- 
                 — 
                 PCU 
                 PCU 
                 PCU 
                 PCU 
               
               
                 TOR P: 
               
               
                 FAN P: 
                 17.0 
                 22.0 
                 22.0 
                 25.0 
                 25.0 
               
               
                 FAN AMPS 
                 — 
                 30.0 
                 30.0 
                 31.5 
                 31.5 
               
               
                 (25 HP/ 
               
               
                 480 V): 
               
               
                 HZ/RPM&#39;S: 
                 60/682 
                 60/682 
                 60/682 
                 60/682 
                 60/682 
               
               
                 HP/VOLTS 
                 50/480 
                 50/480 
                 50/480 
                 50/480 
                 50/480 
               
               
                 NL AMPS: 
                 18.1 
                 18.1 
                 18.1 
                 18.1 
                 18.1 
               
               
                 LOAD 
                 — 
                 18.3 
                 18.2 
                 18.4 
                 — 
               
               
                 AMPS: 
               
               
                 GAS 
                 — 
                 10/112 
                 10/103 
                 10/84 
                 — 
               
               
                 CUFT/SEC.: 
               
               
                   
               
            
           
         
       
     
     Having thus described the preferred embodiments in sufficient detail as to permit those of skill in the art to practice the present invention without undue experimentation, those of skill in the art will readily appreciate other useful embodiments within the scope of the claims hereto attached. For example, although the present invention has been described as useful for the meat meal rendering industry, those of skill in the art will readily understand and appreciate that the present invention has substantial use and provides many benefits in other industries as well. In view of the foregoing descriptions, it should be apparent that the present invention represents a significant departure from the prior art in construction and operation. However, while particular embodiments of the present invention have been described herein in detail, it is to be understood that various alterations, modifications and substitutions can be made therein without departing in any way from the spirit and scope of the present invention, as defined in the claims which follow. 
     In addition to being directed to the embodiments described above and claimed below, the present invention is further directed to embodiments having different combinations of the features described above and claimed below. As such, the invention is also directed to other embodiments having any other possible combination of the dependent features claimed below. 
     The above examples and disclosure are intended to be illustrative and not exhaustive. These examples and description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the attached claims. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims attached hereto.