High humidity steam cooker with continuously running conveyor

Abstract

A steam cooker processes large quantities of food products such as meat, fish, poultry and produce passed therethrough in a spiral conveyor path. The continuously running conveyor is provided with loading and unloading stations outside the cooker and with a continuously operable spray detergent cleaning bath. Efficient cooking is achieved without loss of humidity, flavor or appearance by maintaining water drop free steam at near 100° C. and 100% humidity at a pressure greater than atmospheric and by features of the apparatus including control of steam flow out of the cooking chamber and introduction of cold air thereinto. Two separate steam sources, internal and external, are provided with the internal source comprising a heated pool of water on the floor of the cooker chamber, which is agitated for heat transfer efficiency and to remove fat or drippings from the cooking products. Sanitation means include mounting of machinery parts outside the cooker, access to all sides of the cooking chamber for cleaning, an internal cleaning spray system and other apparatus features.

I claim: 
     
       1. A food cooking system cooking solely with steam foods such as fish, fowl, meats or produce carried through a cooker on a continuously running conveyor belt, comprising in combination, a cooker housing, means passing said conveyor belt through said housing to expose food products within the cooker housing only to said steam as the sole cooking medium, and two sources of steam providing said steam to cook the food products, nozzles for releasing steam located inside said housing, one comprising a steam generator supplying supplemental steam into said housing at said nozzles located thereinside to maintain the atmosphere together with the other steam source at near 100% humidity 100° C. and a pressure above atmospheric, and the other source of steam comprising a pool of water within said housing with steam means for boiling the water to create steam. 
     
     
       2. The system defined in claim 1 having a steam exhaust pipe, and heat control means for said pool of water regulated as a function of the temperature at said exhaust pipe. 
     
     
       3. The system defined in claim 1 having an opening in said housing into which said conveyor belt passes, and means establishing said steam pressure at a sufficient magnitude to discharge steam at a controlled rate from said housing about the entering conveyor belt. 
     
     
       4. The system defined in claim 3 with an opening in said housing out of which the conveyor belt passes and having a steam flow path created within said housing by said nozzles tending to draw air into the latter said opening to produce a flow path out of the former opening thereby circulating air and steam. 
     
     
       5. A system as defined in claim 1 including means driving said conveyor belt through said housing with all mechanisms requiring lubrication mounted in a compartment outside the housing thereby to avoid food contamination. 
     
     
       6. A system as defined in claim 1 wherein the housing is positioned within a secondary housing such as a room where the pressure is maintained above atmospheric. 
     
     
       7. A system as defined in claim 6 including a station for loading food products through which said conveyor belt passes outside said secondary housing so that the food products are maintained at atmospheric pressure until they enter the cooker system whereby the increased pressure and high humidity cause efficient penetration of heat into the products to cook them evenly throughout by establishing a temperature approaching 100° C. 
     
     
       8. A system as defined in claim 1 adapted for processing meat and fowl products which may drip fat into said pool of water, including means continuously skimming the fat from the top of the water to improve the steam capacity thereof. 
     
     
       9. A system as defined in claim 8 wherein the fat skimming means comprises a paddle wheel on one side of the pool generating waves travelling to the other side of the pool and a fat skimmer receiving the crest of the waves and fat residing therein and removing such from the pool of water. 
     
     
       10. A system as defined in claim 8 wherein the heating means for the pool of water comprise heat exchange elements at the bottom of said housing, including means circulating the water over said heat exchange elements to improve the effective steam output efficiency. 
     
     
       11. A system as defined in claim 1 wherein said housing has access doors for entry thereinto on all sides. 
     
     
       12. A system as defined in claim 1 wherein the conveyor belt is passed inside said housing in a spiral path .[.coiling downwardly to carry said foods through said housing from an upper to a lower position in said near 100% humidity atmosphere which prevents water dripping downwardly upon the foods being cooked on the belt.].. 
     
     
       13. A system as defined in claim 1 including means pre-moistening the food products on said conveyor belt before entry into said housing to thereby create an efficient heat interchange surface on the food products for heating by said steam. 
     
     
       14. The system defined in claim 13 wherein the conveyor belt path passes from a loading station at atmospheric pressure into an enclosure above atmospheric pressure and said moistening means comprises means located within said enclosure producing a fine spray mist covering the surface of the food product on the belt without droplets or steaming. .Iadd. 
     
     
       15.  A self-contained continuous food cooking system comprising: a cooker housing which establishes an interior space;   food-conveyance means for introducing food products into said interior space at an inlet of said cooker housing and for removing the food products from said interior space at an outlet of said cooker housing spaced from said housing inlet;   said food-conveyance means defining a generally spiral path of conveyance for said food products in said interior space, which interior path provides a sufficient dwell time for the food products in said interior space as the food products are substantially continually translated along said defined interior path between said housing inlet and said housing outlet;   said cooker housing including (i) an internal pool of water having a surface at a level below said interior path, and (ii) means in heat-exchange relationship to said pool of water for converting a quantity of water in said pool to steam to thereby provide a steam atmosphere within said interior space which directly contacts said food products to at least in part cook the food products during the translation of the food products along said interior path, whereby at least partially cooked food products exit the cooker housing at said outlet thereof. .Iaddend. .Iadd.16. A cooking system as in claim 15, which further comprises skimmer means for removing a residual film of food-cooking by-products from said pool of water. .Iaddend. .Iadd.17. A cooking system as in claim 16, wherein said skimmer means includes a skimmer adapted to collect the removed food-cooking by-products, and means for creating travelling disturbances on said surface of said pool of water which cause said by-products to move towards said skimmer to be collected thereby. .Iaddend. .Iadd.18. A meat cooking system as in claim 15, wherein:   said food-conveyance means includes an endless conveyor belt for supporting and moving with said food products during their translation along said interior path and which includes a return path exterior of said cooker housing between said outlet and inlet, and wherein the system further comprises   means located along said return path exterior of said cooker housing for cleaning food product residue from said endless conveyor before said   
     
     
        conveyor reenters said cooker housing inlet. .Iaddend. .Iadd.19.  A cooking system as in claim 15 wherein said steam is high humidity steam and said food products are directly exposed to said high humidity steam. .Iaddend. .Iadd.20. A cooking system as in claim 15 wherein said food-conveyance means comprises a moving perforated belt and said food products are stationary with respect to said belt and move with said belt. .Iaddend. .Iadd.21. A cooking system as in claim 15 wherein said housing outlet is vertically spaced from said housing inlet. .Iaddend. .Iadd.22. A cooking system as in claim 15 wherein said interior path includes a plurality of stacked convolutions, the travel of said food products along said stacked convolutions in part providing said sufficient dwell time. .Iaddend. .Iadd.23. A cooking system as in claim 22 wherein a lowermost one of said plural convolutions is above the level of the surface of said 
     
     
        pool of water. .Iaddend. .Iadd.24.  A food cooking system for cooking food products carried on a moving conveyor belt, comprising: a cooker housing:   means disposed within said housing for defining a conveyance path,   a conveyor belt disposed along said conveyance path for supporting and conveying said food products along said path,   means coupled to said belt for causing said belt and said food products supported thereby to substantially continually translate along said conveyance path through said housing to expose food products within the housing to steam, said path retaining said translating food products within said housing for at least a desired dwell time, and   a source of steam providing steam to contact and cook the food products, said steam source comprising at least one of the following:   an external steam generator supplying steam into said housing, and   a pool of water within said housing with heating means communicating with   
     
     
        said pool of water for creating steam. .Iaddend. .Iadd.25.  A cooking system as in claim 24 wherein said conveyance path forms a spiral including plural vertically stacked convolutions, the number of said stacked convolutions in part providing said desired dwell time. .Iaddend. .Iadd.26. A cooking system as in claim 24 wherein said steam source provides high humidity steam and said food products are directly exposed 
     
     
        to said high humidity steam. .Iaddend. .Iadd.27.  A cooking system in claim 24 wherein said conveyor belt comprises a perforated belt that moves with said food products. .Iaddend. .Iadd.28. A cooking system as in claim 24 wherein said source of steam is disposed in a lower portion of said cooker housing. .Iaddend. .Iadd.29. A cooking system as in claim 24 wherein steam within said housing condenses and is reheated and recirculated as steam by said steam source. .Iaddend. .Iadd.30. A cooking system as in claim 24 wherein said translation causing means continually 
     
     
        moves said belt. .Iaddend. .Iadd.31.  A continuous food cooking system comprising: a housing;   means for defining an internal conveyance path within said housing,   means disposed along said internal conveyance path for supporting and substantially continually translating food products along said internal path, said food products cooking while within said housing and producing a by-product, said internal path retaining said translating food products within said housing for a dwell time;   internal steam producing means disposed within said housing for producing steam that contacts said food products, said internal steam producing means including:   a water reservoir generally disposed at the bottom of said housing for collecting said by-product, and   a heat exchanger applying heat to said water reservoir to convert some of the water in said reservoir to steam, said steam contacting said food products translating along said path; and   means communicating with said water reservoir for facilitating said steam   
     
     
        conversion by removing said by-product. .Iaddend. .Iadd.32.  A cooking system as in claim 31 wherein said by-product is fat and said facilitating means comprises: means for agitating said water reservoir to produce waves on said reservoir surface; and   skimmer means coupled to said reservoir for skimming said fat by-product from said reservoir surface in response to said waves. .Iaddend. .Iadd.33. A cooking system as in claim 31 wherein:   said housing includes outlet stack means for exhausting a controlled amount of said steam from said housing, and   temperature sensing means coupled to said outlet stack means for sensing the temperature of steam exhausted by said outlet stack means; and   said heat exchanger includes control means for controlling the amount of heat applied thereby to said water reservoir in response to said sensed   
     
     
        temperature. .Iaddend. .Iadd.34.  A cooking system as in claim 31 wherein said internal conveyance path forms a spiral including a plurality of vertically arranged convolutions. .Iaddend. .Iadd.35. A cooking system as in claim 31 wherein said steam producing means produces high humidity steam and said food products are directly exposed to said high humidity 
     
     
        steam. .Iaddend. .Iadd.36.  A cooking system as in claim 31 wherein said supporting and translating means comprises a perforated belt that moves with said food products, said food products resting on said belt. 
     
     
        .Iaddend. .Iadd.37.  A self-contained recirculating continuous steam cooker comprising: a housing having a floor and walls enclosing an interior space;   means disposed within said interior space for supporting and substantially continually translating food products along a conveyance path within said housing, said path retaining said translating food products within said housing and permitting said food products to at least partially cook within said housing for a desired dwell time;   internal steam means disposed within said housing for producing steam, said internal steam means including:   a water reservoir disposed on the floor of said housing and having a surface in contact with said interior space, and   heat exchange means for producing steam, said steam contacting and heating said food products and said housing and thereby forming a condensate, said condensate returning to said water reservoir and recirculating. .Iaddend.   
     
     
        .Iadd.38.  A cooker as in claim 37 further comprising paddle wheel means disposed within said reservoir for agitating said reservoir. .Iaddend. .Iadd.39. A cooker as in claim 37 further comprising: means for agitating said water reservoir; and   means coupled to said reservoir for removing fat by-product from the reservoir surface so as to prevent said fat by-product from inhibiting steam production. .Iaddend. .Iadd.40. A cooker as in claim 37 wherein:   said housing includes outlet stack means for exhausting a controlled amount of said steam from said housing, and   temperature sensing means coupled to said outlet stack means for sensing the temperature of steam exhausted by said outlet stack means; and   said heat exchange means includes control means for controlling the amount of heat applied to said water reservoir in response to said sensed   
     
     
        temperature. .Iaddend. .Iadd.41.  A cooker as in claim 37 wherein said internal steam means produces high humidity steam and said food products are directly exposed to said high humidity steam. .Iaddend. .Iadd.42. A cooker as in claim 37 wherein said supporting and translating means comprises a perforated belt that moves with said food products, said food 
     
     
        products resting on said belt. .Iaddend. .Iadd.43.  A cooking system for cooking food products such as poultry, said cooking system comprising: a housing;   means for defining a conveyance path within said housing, including a belt supporting and substantially continually translating said food products along said path, said path retaining said translating food products within said housing for a desired dwell time such that said food products are heated while within said housing to a desired temperature;   means for providing steam within said housing, said steam contacting said food products and at least in part heating and cooking said food products and causing said food products to produce a fat by-product;   means disposed at the floor of said housing for collecting said fat by-product; and   means connected to said collecting means for removing said collected fat   
     
     
        by-product from said housing. .Iaddend. .Iadd.44.  A system as in claim 43 wherein said collecting means includes: a pool of water within said housing having a surface at a level below a lowermost convolution of said path; and   means for removing fat by-product floating on said surface of said pool of   
     
     
        water. .Iaddend. .Iadd.45.  A cooking systems in claim 44 wherein said removing means comprises skimmer means for removing a residual film of fat by-products from said pool of water. .Iaddend. .Iadd.46. A cooking system as in claim 45, wherein said skimmer means includes a skimmer adapted to collect the removed fat by-products, and means for creating travelling disturbances which cause said film to move towards said skimmer to be 
     
     
        collected thereby. .Iaddend. .Iadd.47.  A cooking system as in claim 43 wherein said conveyance path forms a spiral including plural vertically stacked convolutions. .Iaddend. .Iadd.48. A cooking system as in claim 43 wherein said conveyance path is non-linear. .Iaddend. .Iadd.49. A cooking system as in claim 43 wherein said conveyance path is circular. .Iaddend. 
     
     
        .Iadd.50.  A cooking system as in claim 43 wherein said steam providing means provides high humidity steam and said food products are directly 
     
     
        exposed to said high humidity steam. .Iaddend. .Iadd.51.  A continuous cooking system for cooking food products such as meat, said cooking system comprising: a housing comprising thermally insulated walls and at least one access door;   means for defining a conveyance path within said housing;   a conveyor belt disposed along said path for supporting and substantially continually translating food products along said path;   means mechanically coupled to said belt for moving said belt, said path retaining said translating food products within said housing for a desired dwell time so as to heat said meat products within said housing to a desired temperature; and   steam providing means for providing substantially water droplet free steam within said housing, said steam directly contacting the outer surface of said food products and thereby at least in part heating said food products. .Iaddend. .Iadd.52. A system as in claim 51 further including at least one further heat source means for heating said food products within   
     
     
        said housing. .Iaddend. .Iadd.53.  A cooking system as in claim 51 wherein said conveyance path includes plural vertically stacked paths. .Iaddend. .Iadd.54. A cooking system as in claim 51 wherein said conveyance path is spiral. .Iaddend. .Iadd.55. A cooking system as in claim 51 wherein said steam providing means provides high humidity steam and said food products are directly exposed to said high humidity steam. .Iaddend. .Iadd.56. A cooking system as in claim 51 wherein said food products rest on said 
     
     
        conveyor belt and move with said belt. .Iaddend. .Iadd.57.  A continuous steam cooking apparatus for cooking food products such as meat having an outer fat layer, said apparatus comprising: a housing,   means for defining a conveyance path, said path including an internal conveyance path within said housing and an additional external conveyance path outside said housing, said internal and external paths being connected to at least in part form an endless, continuous path, said internal path retaining said food products translating along said path within said housing for a desired dwell time;   an endless belt disposed along said internal and external paths, said belt adapted for supporting and translating said food products along said paths;   means coupled to said belt for moving said belt along said internal and external paths;   means for providing steam within said housing to come into direct contact with the outer surfaces of said food products supported and translated by said belt so as to at least in part cook said food products; and   cleaning means disposed outside said housing and along said external path for cleaning food product residue from said belt. .Iaddend. .Iadd.58. Apparatus as in claim 57 wherein:   said steam providing means includes: a water reservoir disposed on the floor of said housing, said water reservoir defining a surface below said internal path; and   heat exchange means communicating with said water reservoir for producing steam, said steam contacting and heating said food products and said housing and thereby forming a condensate, said condensate returning to said water reservoir and recirculating as steam; and     said apparatus further includes means for removing said liquid fat by-product from said water reservoir surface so as to prevent said   
     
     
        by-product from inhibiting said steam production. .Iaddend. .Iadd.59.  An apparatus as in claim 57 wherein said steam providing means provides high humidity steam and said food products are directly exposed to said high 
     
     
        humidity steam. .Iaddend. .Iadd.60.  An apparatus as in claim 57 wherein 
     
     
        said food products rest on and move with said belt. .Iaddend. .Iadd.61. An apparatus as in claim 57 wherein said internal path is spiral. .Iaddend. .Iadd.62. An apparatus as in claim 57 wherein said internal path includes plural vertically stacked convolutions. .Iaddend. .Iadd.63. An apparatus as in claim 57 further including premoistening means disposed along said external path between said cleaning means and said housing for premoistening the surface of said food products supported by said belt before said products enter said housing so as to reduce insulation characteristics of said fat layer disposed on said food products and thereby permit said steam to more rapidly cook said food products. .Iaddend. .Iadd.64. A continuous food cooking system comprising: a housing;   means for defining an internal conveyance path within said housing,   means disposed along said internal conveyance path for supporting and substantially continually translating food products along said internal path, said food products cooking while within said housing and producing a by-product, said path having sufficient convolutions to retain said translating food products within said housing for a desired dwell time; and   a steam source providing steam to contact and cook the food products, said steam source comprising at least one of the following:   an external steam generator supplying steam into said housing, and   a pool of water within said housing with heating means communicating with   
     
     
        said pool of water for creating steam. .Iaddend. .Iadd.65.  A cooker as in claim 64 wherein said steam source comprises internal steam producing means disposed within said housing for producing steam that contacts said food products, said internal steam producing means including: a water reservoir disposed at the bottom of said housing for collecting said by-product, and   heat exchange means for applying heat to said water reservoir to convert some of the water in said reservoir to steam, said steam contacting said food products translating along said internal path. .Iaddend. .Iadd.66. A cooker as in claim 64 wherein said conveyance path is spiral. .Iaddend. .Iadd.67. A cooker as in claim 64 wherein said food products are directly exposed to said steam. .Iaddend.