APPARATUS AND METHOD FOR CONTROLLING A CONVEYOR OVEN

• US 20110048245A1
• Filed: 05/21/2010
• Published: 03/03/2011
• Est. Priority Date: 08/28/2009
• Status: Active Grant

• Current Assignee: Middleby Corporation
• Original Assignee: Middleby Corporation
• Inventors: Wiker, John H., Chmiola, Theodore James, Schjerven, William S. SR., Sieron, Mark A., Van Camp, Richard H.
• Granted Patent: US 8,839,714 B2
• Time in Patent Office: Days
• US Class Current: 99/331
• CPC Class Codes: A21B 1/245 with a plurality of air nozzles to obtain an impingement effect on the food
• CPC Class Codes: A47J 37/044 with conveyors moving in a horizontal or an inclined plane A47J37/045, A47J37/046 take precedence
• CPC Class Codes: A47J 37/045 with endless conveyors
• CPC Class Codes: Y02P 60/80 Food processing, e.g. use of renewable energies or variable speed drives in handling, conveying or stacking

Abstract

A conveyor oven includes a controller configured to change the operation of a first set of burners and a second set of burners from a cooking mode to an energy saving mode based at least in part upon detection of the absence of food in the oven chamber. The first set of burners operating at a first intensity during the cooking mode and are off during the energy saving mode. The second set of burners operating at a first intensity during the cooking mode and being adjustable to a different intensity during the energy saving mode, where the second set of burners produce heat during the different intensity.

Claims

1. A conveyor oven having a cooking mode and an energy saving mode, the conveyor oven comprising:

an oven chamber in which food is cooked;

a conveyor moveable to convey the food through the oven chamber;

a first set of one or more burners configured to generate heat for the oven chamber, wherein the first set of one or more burners is operable at a first intensity during the cooking mode and is turned off in the energy saving mode;

a second set of one or more burners configured to generate heat for the oven chamber, the second set of one or more burners operating at a first intensity during the cooking mode and are variable to a different intensity in the energy saving mode, wherein the second set of one or more burners generate heat at the different intensity; and

a controller responsive to the absence of food in the oven chamber, the controller configured to change operation of the first set of one or more burners and the second set of one or more burners from the cooking mode to the energy saving mode based at least in part upon detection of the absence of food in the oven chamber.

2. The conveyor oven of claim 1, further comprising a combustion blower that provides air to at least one of the first set of one or more burners and the second set of one or more burners, wherein the speed of the combustion blower is variable.

3. The conveyor oven of claim 2, further comprising a main blower to circulate air within the oven chamber, wherein the speed of the main blower is variable between the cooking mode and the energy saving mode.

4. The conveyor oven of claim 3, wherein the speed of the combustion blower is variable in response to the speed of the main blower.

5. The conveyor oven of claim 2, wherein the speed of the combustion blower is variable between the cooking mode and the energy saving mode.

6. The conveyor oven of claim 1, further comprising a first valve to regulate flow of gas to the first set of one or more burners and the second set of one or more burners, and a second valve to regulate flow of gas between the first valve and the first set of one or more burners.

7. The conveyor oven of claim 6, wherein the first valve is a modulating control valve and the second valve is an on-off valve.

8. The conveyor oven of claim 1, wherein the controller changes operation of the first set of one or more burners and the second set of one or more burners between the cooking mode and the energy saving mode based upon passage of a predetermined period of time since detection of the absence of food in the oven chamber.

9. A conveyor oven having a cooking mode and an energy saving mode, the conveyor oven comprising:

an oven chamber in which food is cooked;

a conveyor moveable to convey the food through the oven chamber;

a first valve configured to regulate the flow of gas to a first set of one or more burners and a second set of one or more burners, where gas flows through the first valve at a first flow rate during the cooking mode and is variable to a different flow rate during the energy saving mode, wherein the first valve allows at least some gas to flow therethrough at the different flow rate;

a second valve configured to regulate the flow of gas between the first valve and the first set of one or more burners, where gas flows through the second valve at a first flow rate during the cooking mode and is restricted from flowing therethrough during the energy savings mode; and

a controller responsive to the absence of food in the oven chamber, wherein the controller adjusts the first valve and the second valve between the cooking mode and the energy saving mode in response to detection of the absence of food in the oven chamber.

10. The conveyor oven of claim 9, wherein the first set of one or more burners is operable at a first intensity during the cooking mode and is turned off in the energy saving mode.

11. The conveyor oven of claim 9, wherein the second set of one or more burners is operable at a first intensity during the cooking mode and is variable to a different intensity in the energy saving mode.

12. The conveyor oven of claim 9, further comprising a main blower for circulating air within the oven chamber, wherein the speed of the main blower is adjustable between the cooking mode and the energy saving mode.

13. The conveyor oven of claim 12, further comprising a combustion blower that provides air to at least one of the first set of one or more burners and the second set of one or more burners, wherein the controller adjusts the speed of the combustion blower in response to the speed of the main blower.

14. The conveyor oven of claim 9, wherein the first valve is a modulating control valve and the second valve is an on-off valve.

15. The conveyor oven of claim 9, wherein the controller changes operation of the first set of one or more burners and the second set of one or more burners between the cooking mode and the energy saving mode based upon passage of a predetermined period of time since detection of the absence of food in the oven chamber.

16. A conveyor oven comprising:

an oven chamber in which food is cooked;

a conveyor moveable to convey the food through the oven chamber;

a main blower that circulates air within the oven chamber, the main blower operable at a first speed, a second speed slower than the first speed, and a third speed slower than the second speed;

at least one gas burner;

a combustion blower that provides air to the at least one gas burner; and

a controller responsive to the absence of food in the oven chamber and the activation or increase in speed of the combustion blower, the controller configured to change the speed of the main blower from the first speed to the second speed based at least in part upon the detection of the absence of food in the oven chamber and to change the speed of the main blower from the second speed to the third speed based at least in part upon the detection of the activation or increase in speed of the combustion blower.

17. The conveyor oven of claim 16, wherein the controller adjusts the speed of the combustion blower in response to the speed of the main blower.

18. The conveyor oven of claim 16, wherein the second speed of the main blower is the lowest possible operating speed where the amount of air circulated through the oven by the main blowers is sufficient to maintain the flame of at least one gas burner without requiring assistance from the combustion blower.

19. The conveyor oven of claim 16, wherein the combustion burner is off during the cooking mode.

20. The conveyor oven of claim 16, wherein the controller changes operation of the first set of one or more burners and the second set of one or more burners between the cooking mode and the energy saving mode based upon the passage of a predetermined period of time since detection of the absence of food in the cooking chamber.

21. A conveyor oven comprising:

an oven chamber in which food is cooked;

a conveyor moveable to convey the food through the oven chamber;

a main blower that circulates air within the oven chamber, the main blower operable at a first speed, a second speed slower than the first speed, and a third speed slower than the second speed;

at least one gas burner;

a gas burner airflow rate at least partially defined by the speed of the main blower; and

a controller responsive to the absence of food in the oven chamber and the gas burner airflow rate, the controller configured to change the speed of the main blower from the first speed to the second speed based at least in part upon the detection of the absence of food in the oven chamber and to change the speed of the main blower from the second speed to the third speed when the gas burner airflow rate exceeds a predetermined minimum.

22. The conveyor oven of claim 21, further comprising a combustion blower that provides air to the at least one gas burner.

23. The conveyor oven of claim 22, wherein the airflow of the combustion blower and the airflow of the main blower combine to at least partially produce the gas burner airflow rate.

24. A conveyor oven having a cooking mode and an energy saving mode, the conveyor oven comprising:

an oven chamber in which food is cooked;

a conveyor moveable to convey the food through the oven chamber;

a first set of one or more burners configured to generate heat for the oven chamber, wherein the first set of one or more burners is operable at a first intensity during the cooking mode and is turned off in the energy saving mode;

a second set of one or more burners configured to generate heat for the oven chamber, the second set of one or more burners is operable at a first intensity during the cooking mode and is variable to a different intensity in the energy saving mode; and

wherein a gas burner airflow rate passing through at least one of the burners of the first set of one or more burners or at least one of the burners of the second set of one or more burners is variable between the cooking mode and the energy saving mode.

25. The conveyor oven of claim 24, wherein the gas burner airflow rate is variable by changing the airflow of at least one of a main blower and a combustion blower.

26. The conveyor oven of claim 24, wherein the gas burner airflow rate is variable by changing the setting of a damper.

27. A conveyor oven comprising:

an oven chamber in which food is cooked;

a conveyor moveable to convey the food through the oven chamber;

at least one gas burner having a gas burner airflow rate pass therethrough;

a blower that circulates air; and

a damper adjustable between a first configuration and a second configuration that is different from the first configuration;

wherein the damper is configured to adjust the gas burner airflow rate.

28. The conveyor oven of claim 27, wherein the conveyor oven has a cooking mode and an energy saving mode and wherein the damper is in the second configuration during the cooking mode and is adjustable to the first configuration in the energy saving mode.