in describing a preferred embodiment of the invention illustrated in the drawings , specific terminology will be resorted to for the sake of clarity . however , the invention is not intended to be limited to the specific terms so selected , and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose . with reference to the drawings , in general , and to fig1 in particular , a system for conducting a method of producing food grade poultry oil and meal is generally designated as 10 . with reference to its orientation in fig1 the required apparatus is primarily housed within a building 12 having a loading dock 14 . discarded chicken portions from a chicken slaughtering operation are transported in portable containers by truck and delivered to building 12 at the truck dock 14 through entrance 16 . the food product is maintained at a temperature below 55 ° f . to ensure food quality . the delivered food product is then transported to a dumper mechanism 18 which inverts the food containers and dumps its contents onto an inclined variable speed belt conveyor 20 . the conveyor 20 as illustrated in fig2 and 3 , includes a plurality of rollers 22 about which extends a continuous belt 24 . the rollers 22 are driven by a motor 26 having a pulley 28 connected to a leading roller 30 so as to turn the belt 24 and convey food product between vertically rising guide walls 32 . the product moved by inclined conveyor 20 is dumped into the cooking vat 34 along guide 36 . the cooking vat 34 includes a drive chain belt 38 to which are connected a plurality of equally spaced extension arms 40 , terminating in paddles 42 , for conveying food product through the cooking vat . the chain belt 38 extends across the vat 34 and between two drive cog wheels 44 which are driven by a constantly variable speed , hydraulic drive unit 46 through a drive shaft 48 passing through the center of the drive cog wheels 44 . the chain belt 38 is also passed around three sets of idler cog wheels 50 , 52 and 54 . the idler cog wheels 50 are connected together by a shaft 56 ( similar to the arrangement for drive cog wheels 44 ) whereas the idler cog wheel sets 52 and 54 run independently of each other . the chain belt 38 extending across the width of the cooking vat 34 , passes , at its edges , between stainless steel angle guides 58 , within the vat , which includes a layer of teflon non - stick coating . above the cooking vat 34 , the chain belt is guided by horizontally oriented support 60 braced above the vat by legs 62 . in the cooking vat 34 , at its inlet end 64 , is located a six inch diameter inlet pipe 66 which leads to an elongated pipe 68 having a plurality of openings 70 , with a pipe 68 leading off of the inlet pipe 66 on opposite sides of the cooking vat . heated oil passes through openings 70 in a direction towards the discharge end 72 of the cooking vat 34 at an angle of approximately 22 . 5 °. oil directed through the openings 70 will therefore be directed towards the discharge end and aid in conveying food product through the cooking vat , below the oil level 74 , for total contact , heating and cooking of the food product being processed . at the discharge end 72 of the cooking vat 34 , there is a 10 inch diameter outlet pipe 76 for removal of oil from the cooking vat . as the paddles 42 move through the oil in the cooking vat , in the direction from the inlet end 64 to the discharge end 72 , food product is conveyed up along a screen 78 located at the discharge end 72 . smaller particles of food product and / or fat passing through the screen encounter a high speed rotating screen 80 having short projections 82 to move the smaller particles passing through screen 78 so as to prevent the small particles from entering the outlet pipe 76 . the rotating screen 80 is cleaned by an air line outlet 84 which provides a constant flow of air discharged through the screen . as the paddles pass over the screen 78 , a teflon no - stick coating wiper strip 86 , wipes product being drawn to the screen to the discharge end 72 of the cooking vat . it is understood as being within the scope of the present invention to have a plurality of paddles 42 spaced laterally across the chain conveyor 38 so as to move food product through the cooking vat . each of the paddles 42 may be interconnected by projections 86 extending laterally from the side edges of the paddles 42 . returning to fig1 in the operation of the cooking vat 34 , oil withdrawn from outlet pipe 76 is conveyed by conduit 88 to a pump station 90 . the pump station divides a small portion of the heated oil from the main supply of extracted oil and passes this small oil portion through conduit 92 , to a heat exchanger 94 which transfers some of the heat from the oil to heat water to be stored in a hot water tank 96 . the hot water tank 96 is used with a high pressure pump 98 in a cleaning operation of the apparatus of the present invention . after transfer of heat in heat exchanger 94 to water to be stored in tank 96 , the oil is returned by conduit 100 to the pump station 90 . the majority of oil withdrawn through outlet pipe 76 and the oil returned by conduit 100 back to the pump station 90 is transferred by conduit 102 to a latco cyclonic liquid filter 104 for removal of suspended particles of cooked fat in the oil . the cooked fat particles separated from the oil are transferred by conduit 106 for subsequent processing . the filtered oil is then transferred by conduit 108 , to a direct fired heat exchanger 110 . at the heat exchanger 110 , the oil is heated to a temperature in the range of 360 ° to 380 °, and preferably 380 °. the heated oil is then transferred by conduit 112 to the inlet pipe 66 at the inlet end 64 of the cooking vat 34 . the pumps 114 in the pumping station 90 withdraw oil from the cooking vat and return oil to the cooking vat at a rate of 680 to 860 gpm . this very rapid movement of oil through the cooking vat , at elevated temperatures , provides for a high protein content meal due to the removal of moisture and fat from the chicken pieces being processed . in addition , a continuous oil level is maintained by a weir and strainer 116 which siphons oil and fat from an upper surface of the oil in the cooking vat and transfers the extracted oil and fat through conduit 118 . conduit 118 passes to a stein filter 120 and then through conduit 122 to a star filter 124 for cleaning and polishing of the oil prior to the oil being conveyed through conduit 126 to an oil storage tank 128 . returning to the further processing of the food product conveyed through the cooking vat 34 by paddles 42 and the force of heated oil directed towards the discharge end 72 , the solid product is conveyed by a screw auger conveyor 130 in a direction perpendicular to the direction of extension of the cooking vat 34 . the solid product is delivered to another screw auger conveyor 132 which extends perpendicular to the conveyor 130 . excess oil is allowed to drain from the solid product as the product is conveyed along conveyors 130 and 132 . the solid product is then delivered to a press 134 which compresses the solid product to remove any excess oil . the oil removed by the press 130 is conveyed by conduit 136 to a sedimentation tank 138 . in addition , the suspended particles of cooked fat removed by the filter 104 are conveyed through conduit 106 to the sedimentation tank 138 for further processing . oil separated from solid product in the sedimentation tank is removed by conduit 140 and delivered to the filters 120 and 124 for ultimate delivery to the storage tank 128 . the solid product from the sedimentation tank is moved by screw auger conveyor 141 to another screw auger conveyor 142 and return delivery back to the screw auger 132 and return delivery to the press 134 . the recycling of solid product through the press 134 ensures maximum oil removal from the solid product . solid product produced by the press 134 is transferred by screw auger conveyor 144 to screw auger conveyor 146 and delivery to a hammer mill 148 . at hammer mill 148 , dry solid product is crushed and ground into a fine chicken meal . the chicken meal is conveyed by screw auger conveyors 150 and 152 to a meal storage tank 154 . by the method using the apparatus described , a high quality food product is produced with a high protein content . this superior product results from the continuous extraction of fat and moisture by cooking in high temperature oil with continuous subsequent removal of the oil from the cooked food product . the foregoing description should be considered as illustrative only of the principles of the invention . since numerous modifications and changes will readily occur to those skilled in the art , it is not desired to limit the invention to the exact construction and operation shown and described , and , accordingly , all suitable modifications and equivalents may be resorted to , falling within the scope of the invention .
a method and apparatus for producing increased protein chicken meal . product is loaded into a cooking vat that is 40 feet long by 5 feet wide by 4 feet deep , with a system of moving chain conveyors and paddles . these conveyors move the product at a predetermined speed through oil maintained at a temperature of approximately 360 ° to 380 ° f . for the entire length of the vessel , and dumps the product at the opposite end of entry . oil is circulated through the vat at a rate of approximately 680 to 860 gallons per minute to allow for the rapid removal of fat and moisture from skin and meat in a continuous process . the volume of oil in the cooking vat is approximately 4 , 500 gallons .