Patent GB-1379370-A (GB)
Title: Method of and apparatus for continuous cooking of food
IPC: A23L5/10
Filed: 1973-03-13
Abstract: 1379370 Cooking food ELECTROLUX AB 13 March 1973 [15 March 1972] 12120/73 Heading A2E [Also in Division A4] A method of continuously cooking food, comprises moving the food through zones in an oven which are heated by hot air circulated in paths above and below the food and generally transverse to the direction of food movement, the air temperatur being controlled separately in each zone. An oven comprises an intake portion 10, Fig. 1, a discharge portion 11 and several oven sections 12-15, a conveyer 16 passing through the. oven and an air circulating system in each section 12-15 for circulating hot air in a direction generally transverse to the conveyer 16 and having air temperature controlling means. Conduits 17-19 with valves vent the sections 10-15 and conduits 21 with valves 20 connect the sections 12-15 to a vapour supply conduit 22. The apparatus can be combined in series with other automatic machines for, for example, spraying, packing, freezing &c of the food. Oven Sections: Each oven section has a door 24 on hinges 23. A motor 25, an adjustable air inlet 26 and a box 27 for a thermometer and a thermostat are situated outside the door 24. Wires 28, 29 lead to a control unit. The motor 25 operates a fan wheel 31, Fig. 3, via a shaft 30 which is cooled by air passing through a coaxial channel 33. The air is heated by tubular elements 35 disposed in rings around the fan wheel 31 and passes into tapering channels 36, 37 within a heat insulator 38 around the oven. Plates mounted on frames 40, 41 have slits (39), Fig. 4, (not shown) which induuce turbulence. The air passes through a slot 45 in a sheet metal box 46 having an opening 47 at the inlet side of the fan wheel 31. A regulator connected to a sensor 48 determines the temperature of the diameter 35 and the air current can be regulated by throttling the slot 45. The slits (39) can be regulated by movable plates (49, 50), Fig. 5, (not shown). When the door 24 is opened, the elements 35, the fan wheel 31 and the sensor 48 are swung away and allow the frames 40, 41 and the box 46 to be drawn out of the oven for cleaning. Plates (53, 54) are shaped to guide air drawn from the fan into the channels 36, 37. Liquid used for cleaning flows to the lowest point 55 in the oven and through a conduiut 56 to a collecting vessel in the oven support 57. Operation. A cooling device such as a water bath is provided in the intake portion 10 for the lower run of the conveyor 16, and nozzles for high-pressure washing are provided in the discharge portion 11. Compressed air may also be blown to dry the conveyer. To process meat-balls, the four oven sections 12-15 are set at a temperature of 200, 250-300, 300-350 and 400‹C respectively and the belt driven at 1m/mt. To maintain the different temperatures in the various sections, each section has a lower side plate 58 and an upper side plate (61) adjustable by screws (59) on a bracket (60). The gap between the plates (58, 61) being just sufficient to allow the food stuff 44 to pass between them. Steam may be supplied through the conduit 22 to steam the foodstuff 44. The belt 16 may be lengthened and more oven sections added to increase the capacity of the apparatus.