Self-cleaning oven

Abstract

A self-cleaning, gas-fired tunnel oven is provided. One embodiment of the oven provides a self-cleaning, gas-fired tunnel oven for cooking food products. The oven includes a control system that regulates oven temperature during a pyrolitic, self-cleaning procedure for incinerating contaminants that accumulate inside; a burner for cooking food products and incinerating contaminants; a modulating air and fuel control system arranged for proportionally delivering air and fuel to the burner; a plurality of convection air fingers for directing heated air toward the food products; a collapsible conveyor, capable of fitting into the oven when collapsed, for passing the food products through the oven; a plurality of blowers, each having a dedicated speed controller; a floating cooking chamber; and a vent system that maintains a negative pressure in the oven during the self-cleaning procedure

Description

RELATED APPLICATIONS [0001] The present patent application claims the benefit of prior filed U.S. provisional patent application Ser. No. 60 / 449,545, filed on Feb. 21, 2003, the entire contents of which are hereby incorporated by reference.FIELD OF THE INVENTION [0002] The present invention relates to a gas-fired tunnel oven, and particularly a gas-fired conveyor oven. BACKGROUND AND SUMMARY OF THE INVENTION [0003] Commercial, gas-fired tunnel ovens equipped with conveyors produce, among other things, pizzas, cookies, bread, cakes and donuts. Each oven routinely processes a large volume of food products and, as a result, becomes rather dirty. Bits of the food products themselves, burned food products, and soot from the burners are typical sources of contamination that accumulate during use. [0004] Gas-fired tunnel ovens traditionally have been cleaned manually with detergent and acid solutions. The oven must be taken apart for cleaning by these methods. In addition to the oven walls...

AI Technical Summary

Benefits of technology

[0007] A self-cleaning, gas-fired tunnel oven that cleans by pyrolysis is provided. The oven is used with a conveyor for food products, which may be collapsed and placed inside the oven for pyrolitic cleaning. The oven includes a control system that regulates the oven temperature and duration of the self-cleaning operation and deters people from opening the oven during the self-cleaning operation.

[0008] The control system also modulates combustion air and heating gas to one or more burners within the oven. A modulating control system regulates the flow of air or heating gas to the burner or burners. The ratio of airflow to heating gas flow is controlled directly so that the ratio of air to fuel gas flowing to the burner is approximately the same over a range of heating loads. The control system that proportionally coordinates the flow of air and fuel may be, for example, a mechanical linkage between the valves or one or more electric or pneumatic controllers that send positioning signals to the valves. With modulating control of combustion air and heating gas, the oven operates cleanly and efficiently over a wide range of heating loads.

[0010] The oven includes a floating cooking chamber, which can withstand pyrolitic cleaning temperatures and repeated pyrolitic cleaning cycles without warping, cracking or developing metal fatigue. Various components of the floating cooking chamber are joined in a sliding fit that permits the floating cooking chamber to expand and contract in response to temperature changes without applying excessive mechanical stress to the components.

[0011] The oven also includes a vacuum exhaust system for exhausting pyrolysis products. In one version, the convection blowers are situated to deliver convection air to the oven and, also, maintain the oven under a negative pressure with respect to the kitchen. In another version, an inducer blower extracts the exhaust air from the oven and delivers it to a disposal system. The negative pressure prevents combustion products produced during the self-cleaning process from escaping to the kitchen.

[0012] The oven is equipped with an active cooling system in which air from the kitchen is passed through ducts that cool the exterior surfaces of the oven. The oven includes heat-slingers to protect the shafts of the convection blowers from overheating. Additionally, the oven includes self-cleaning fingers for a jet-impingement convection system that also clean the conveyor.

Problems solved by technology

Each oven routinely processes a large volume of food products and, as a result, becomes rather dirty.

Bits of the food products themselves, burned food products, and soot from the burners are typical sources of contamination that accumulate during use.

Cleaning by the traditional methods is tedious and expensive.

Commercial bakers do not normally have access to this much electrical current, and the cost of installing high current electrical service is a significant financial barrier for most bakers.

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