Conveyor oven apparatus and method

A conveyor oven having a first mode and a second mode of operation, the conveyor oven comprising:

• a tunnel in which food is cooked;
• a conveyor moveable to convey the food through the tunnel;
• a first set of one or more burners to generate heat for the tunnel;
• a first valve to regulate the flow of gas to the first set of one or more burners, where gas flows through the first valve at a first flow rate during the first mode of operation and is variable to a different flow rate during the second mode of operation, wherein the first valve allows at least some gas to flow therethrough at the different flow rate;
• a second set of one or more burners to generate heat for the tunnel;
• a second valve to regulate the flow of gas to the second set of one or more burners, where gas flows through the second valve at a first flow rate during the first mode of operation and is prevented from flowing therethrough during the second mode of operation;
• and
• a controller responsive to a signal associated with an absence of food in the tunnel and to a temperature of the tunnel, wherein the controller adjusts (i) the first valve and the second valve between the first mode of operation and the second mode of operation based at least in part upon the signal, and (ii) the flow of gas through the first valve to maintain the tunnel at substantially a steady state temperature in the second mode of operation based at least in part on changes in the temperature of the tunnel.

A conveyor oven for cooking food product having a first and second mode of operation, the conveyor oven comprising:

• a tunnel in which food is cooked;
• a conveyor for moving the food through the tunnel;
• a heat source operable to generate heat to be provided to the tunnel, wherein the heat source comprises a first set of one or more heating elements and a second set of one or more heating elements;
• a fan operable to move air in the tunnel;
• and
• at least one controller that
• controls at least one of the fan and the heat source, and
• is responsive to the detection of the absence of food from the tunnel and to a temperature of the tunnel, wherein the controller changes the oven from the first mode of operation to the second mode of operation based at least in part upon the detection of the absence of food product from the tunnel, and in the second mode of operation (i) the fan moves air in the tunnel at a speed that is reduced from the speed of the fan when the oven was in the first mode of operation, (ii) the output of the first set of one or more heating elements is adjusted in response to a change in temperature in the tunnel to maintain the oven substantially at a first steady state temperature, and (iii) the second set of one or more heating elements is turned off.

A conveyor oven for cooking food product having a first, second, third and fourth mode of operation, the conveyor oven comprising:

• a tunnel in which food is cooked in the first mode of operation;
• a conveyor for moving the food through the tunnel;
• a heat source operable to generate heat to be provided to the tunnel such that the tunnel is maintained substantially at a first steady state temperature in the first mode of operation;
• a fan operable to move air in the tunnel;
• and
• at least one controller that
• controls at least one of the fan and the heat source, and
• is responsive to the detection of the absence of food from the tunnel and to a temperature of the tunnel, wherein the controller changes the oven from (a) the first mode of operation to the second mode of operation based at least in part upon the passage of a first period of time indicating the absence of food product from the tunnel, wherein in the second mode of operation (i) the fan moves air in the tunnel at a speed that is reduced from the speed of the fan when the oven was in the first mode of operation and (ii) the output of the heat source is adjusted in response to a change in temperature in the tunnel to maintain the oven substantially at the first steady state temperature, (b) the second mode of operation to a third mode of operation based at least in part upon the passage of a second period of time indicating the absence of food from the tunnel, wherein in the third mode of operation the output of the heat source is reduced to maintain the oven substantially at a second steady state temperature that is lower than the first steady state temperature, and (c) the third mode of operation to the fourth mode of operation based at least in part upon the passage of a third period of time indicating the absence of food from the tunnel, wherein in the fourth mode of operation the heat source is turned off.