초록 ▼

An infrared tunnel oven includes one or more oven tiers each having a horizontal cooking tunnel with entrance and exit at opposite ends, the tier(s) being supported by a base. Each tunnel is divided along its length into multiple heating zones. The roof and hearth surfaces of each tunnel are heated

An infrared tunnel oven includes one or more oven tiers each having a horizontal cooking tunnel with entrance and exit at opposite ends, the tier(s) being supported by a base. Each tunnel is divided along its length into multiple heating zones. The roof and hearth surfaces of each tunnel are heated by electrical heating panels for direct IR emission from the roof and hearth for direct absorption by food products conveyed through the tunnel by a continuous speed-controllable conveyor. Microprocessor-controlled circuitry monitors, by a thermocouple arrangement, the temperature of the roof and hearth in each zone, controlling the electric heating panels to maintain preselected roof and hearth temperatures in each such zone. The microprocessor also controls the conveyor speed for conveying of products along the length of the tunnel within a preselected cooking time. User selection of temperatures in the different zones and cooking time, as well as other functions, is provided by keypad entry. Temperatures and cooking times and other information are displayed to the user. Lateral zoning in addition to longitudinal zone is provided by other embodiments. The oven provides a method of profiled cooking of food products.

대표청구항 ▼

1. In an infrared tunnel oven for cooking of food products by infrared radiant energy, including at least one tunnel over tier having a tunnel-form cooking chamber having an entrance and exit at opposite ends, the chamber having a roof and a hearth, a plurality of infrared heating means extending ab

1. In an infrared tunnel oven for cooking of food products by infrared radiant energy, including at least one tunnel over tier having a tunnel-form cooking chamber having an entrance and exit at opposite ends, the chamber having a roof and a hearth, a plurality of infrared heating means extending above the roof and beneath the hearth for respective heating of roof and hearth to predetermined temperatures for direct emission from the roof and hearth of infrared radiant energy for absorption by food products conveyed through the chamber, a speed-controllable conveyor for carrying food products through the chamber, the chamber being longitudinally divided into a plurality of different heating zones, the improvement comprising electronic control circuit means including temperature sensing means and conveyor speed sensing means and a single microprocessor, responsive both to the temperature sensing means and the speed sensing means, for simultaneously controlling the heating means and the conveyor for causing the food products to be heated according to a preselected cooking profile while carried by the conveyor through the chamber. 2. In an infrared tunnel oven for cooking of food products by infrared radiant energy, including at least one tunnel oven tier having a tunnel-form cooking chamber having an entrance and exit at opposite ends, the chamber having a roof and a hearth, a plurality of infrared heating means extending above the roof and beneath the hearth for respectively heating of roof and hearth to predetermined temperatures for direct emission from the roof and hearth of infrared radiant energy for absorption by food products conveyed through the chamber, a speed-controllable conveyor for carrying food products through the chamber, the chamber being longitudinally divided into a plurality of different heating zones, the improvement comprising electronic control circuit means including temperature sensing means and conveyor speed sensing means and a single microprocessor, responsive both to the temperature sensing means and the speed sensing means, for simultaneously controlling the heating means and the conveyor for causing the food products to be heated according to a preselected cooking profile while carried by the conveyor through the chamber, said microprocessor: (a) monitoring the emission temperature of the roof and hearth in each of the zones; (b) controlling heating units to maintain preselected roof and hearth emission temperatures; (c) monitoring the speed of the conveyor; and (d) controlling the conveyor speed to convey food products through the chamber in a preselected cooking time. 3. In an infrared tunnel oven according to claim 2, the improvement further characterized by the electronic control circuit means including selector means for user entry of preselected roof and hearth temperatures in each of the zones and preselected cooking time. 4. In an infrared tunnel oven according to claim 3, the selector means including a keypad and random access memory means of the electronic control circuit for retaining keypad selection of preselected roof and hearth temperatures and preselected cooking time. 5. In an infrared tunnel oven according to claim 4, the electronic control circuit means including display means for display of at least the preselected temperatures and cooking time. 6. In an infrared tunnel oven according to claim 3, the roof and hearth being each constituted by a corresponding plurality of plates in end-to-end but slightly separated relationship, the heating means comprising at least one electrically-energizable planar infrared heating panel lying proximately above and below the respective roof and hearth plates. 7. In an infrared tunnel oven according to claim 6 the temperature sensing means including a plurality of thermocouples in intimate thermal relationship to the respective roof and hearth plates for sensing infrared emission temperatures thereof in the different zones. 8. In an infrared tunnel oven according to claim 7, the control circuit means including cold junction thermocouple compensation means for providing referencing of temperatures sensed by the thermocouples relative to room temperature. 9. In an infrared tunnel oven according to claim 7, the control circuit means including differential amplifiers interconnected with respective ones of the thermocouples, a multiplexer interconnected with the differential amplifiers for providing a series of analog temperature signals corresponding to the emission temperatures sensed by the thermocouples according to data addresses of the thermocouples provided by the microprocessor, and analog-to-digital converter means for converting such analog signals to BCD signals for being provided to the microprocessor, read only memory means including stored data for comparison by the microprocessor with the BCD signals for providing by the microprocessor of addressed heating signals for proportionally controlling the extent of energizing of the respective infrared heating panels to control said emission temperatures in the different zones, address latch means responsive to the addressed heating signals, and driver means respectively interconnected with the infrared heating panels for effecting energization of such panels in response to the address latch means. 10. In an infrared tunnel oven according to claim 3, the conveyor including having a variable speed D.C. motor for conveyor driving at a speed dependent upon the motor speed, the conveyor speed sensing means comprising at least one Hall-effect sensor for sensing the motor speed, and circuit means for providing speed signals from the Hall-effect sensor to the microprocessor, the microprocessor being operative for data correlation of the speed signals with a preselected cooking time, and for providing speed control data for controlling motor speed, the electronic control circuit means including data-to-pulsewidth converter means for converting the speed from the microporcessor to a pulse-form signal having a pulsewidth determining motor speed. 11. In an infrared tunnel oven according to claim 1, the oven chamber being also divided laterally into different zones. 12. In an infrared tunnel oven according to claim 11, the oven chamber having two halves defining the lateral zoning, the roof and hearth in each half being separately maintainable at predetermined temperatures. 13. In an infrared tunnel oven according to claim 12, the improvement further characterized by removable barrier means extending longitudinally along the chamber between the two chamber halves for providing thermal separation of the two chamber halves. 14. In an infrared tunnel oven according to claim 12, the speed-controllable conveyor comprising first and second independently speed-controllable conveyor means extending respectively longitudinally along the chamber halves in side-by-side relationship. 15. In an infrared tunnel oven for cooking of food products and the like by infrared radiant energy, including at least one oven tier defining a tunnel-form cooking chamber having an entrance and exit at opposite ends, the chamber having a roof and a hearth, a plurality of infrared heating means extending above the roof and beneath the hearth, respectively, for heating of the roof and hearth to predetermined temperatures for direct emission from the roof and hearth of infrared radiant energy for absorption by food products conveyed through the chamber, speed-controllable conveyor means for carrying food products through the chamber, the chamber being longitudinally divided into a plurality of different heating zones, the improvement comprising electronic control circuit means, including temperature sensing means and conveyor speed sensing means and a microprocessor, responsive both to the temperature sensing means and the conveyor sensing means, for: (a) preselecting roof and hearth temperatures in each zone; (b) measuring the roof and hearth temperatures in each zone; (c) controlling the infrared heating means to maintain substantially the preselected hearth and roof temperatures in each zone; (d) preselecting a cooking time for food products to be conveyed successively through the zone along the length of the chamber; and (e) controlling the speed of the conveyor means to cause the food products to be conveyed through the length of the tunnel within said preselected cooking time; whereby the food products may be rapidly, accurately and uniformally cooked according to a desired cooking profile by being differentially heated in the different zones while being conveyed through the zones in a precisely time-controlled manner.