APPARATUS AND METHOD FOR CONTROLLING A CONVEYOR OVEN
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.
This application is a continuation of U.S. patent application Ser. No. 14/469,192, filed Aug. 26, 2014, which is a continuation of U.S. patent application Ser. No. 12/785,050, filed May 21, 2010, now U.S. Pat. No. 8,839,714, which is a continuation-in-part of U.S. patent application Ser. No. 12/550,034, filed Aug. 28, 2009, the entire contents of all of which are hereby incorporated by reference.
BACKGROUNDConveyor ovens are commonly used for cooking a wide variety of food products, such as for cooking pizzas, baking and toasting bread, and the like. Examples of such ovens are shown, for example, in International Patent Application No. PCT/2009/030727, the entire contents of which are incorporated herein by reference.
Conveyor ovens typically have metallic housings with a heated tunnel extending therethrough, and one or more conveyors running through the tunnel. Each conveyor (in the form of a conveyor belt, for example) transports food items through the heated oven tunnel at a speed calculated to properly bake food on the conveyor belt during the time the conveyor carries the food through the oven. Conveyor ovens generally include a heat delivery system that may include one or more blowers supplying heated air to the tunnel, such as from a plenum to the tunnel. In some conveyor ovens, the hot air is supplied to the tunnel through passageways that lead to metal fingers discharging air into the tunnel at locations above and/or below the conveyor. The metal fingers act as airflow channels that deliver streams of hot air which impinge upon the surfaces of the food items passing through the tunnel on the conveyor. In modern conveyor ovens, a microprocessor-driven control can be employed to enable the user to regulate the heat provided to the tunnel, the speed of the conveyor, and other parameters to properly bake the food item being transported through the oven.
Some conveyor ovens include one or more gas burners positioned to heat air (e.g., in a plenum) before it is supplied to the tunnel to heat the food. In such ovens, the gas burner can include a modulating gas valve providing fuel to the burners, and a combustion blower providing enough air for efficient combustion of the fuel. An oven controller can monitor the temperature at one or more locations within the tunnel, and can adjust the modulating gas valve to provide more or less heat to the tunnel. If the measured temperature is lower than a set point temperature, the modulating gas valve is adjusted to supply more fuel. Conversely, if the measured temperature is higher than the set point temperature, the modulating gas valve is adjusted to supply less fuel. In some conventional ovens, the combustion blower and the modulating fuel valve are adjusted proportionally. For example, if the modulating fuel valve is adjusted to double the amount of fuel output, the speed of the combustion blower is also doubled.
SUMMARYSome embodiments of the present invention provide 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, and 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. The conveyor oven can also include a second set of one or more burners configured to generate heat for the oven chamber. The second set of one or more burners can operate at a first intensity during the cooking mode and can be variable to a different intensity in the energy saving mode in which the second set of one or more burners generates heat at the different intensity. The conveyor oven can also include a controller responsive to the absence of food in the oven chamber, with the controller being 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 the detection of the absence of food in the oven chamber.
Some embodiments of the present invention provide a conveyor oven having a cooking mode and an energy saving mode, wherein the conveyor oven comprises an oven chamber in which food is cooked, a conveyor moveable to convey the food through the oven chamber, and 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. The gas flows through the first valve at a first flow rate during the cooking mode, and is variable to a different flow rate in the energy saving mode in which the first valve allows at least some gas to flow therethrough at the different flow rate. The conveyor oven can also include a second valve configured to regulate the flow of gas between the first valve and the first set of one or more burners. The gas can flow through the second valve at a first flow rate during the cooking mode and is restricted from flowing during the energy saving mode. The conveyor oven can also include 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.
Some embodiments of the present invention provide a conveyor oven comprising an oven chamber in which food is cooked, a conveyor moveable to convey the food through the oven chamber, and a main blower that circulates air within the oven chamber. The main blower can be operable at a first speed, a second speed slower than the first speed, and a third speed slower than the second speed. The conveyor oven can also include 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 can be 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 is configured to change the speed of the main blower from the second speed to the third speed based at least upon the detection of the activation or increase in speed of the combustion blower.
Some embodiments of the present invention provide a conveyor oven comprising an oven chamber in which food is cooked, a conveyor moveable to convey the food through the oven chamber, and a main blower that circulates air within the oven chamber. The main blower can be operable at a first speed, a second speed slower than the first speed, and a third speed slower than the second speed. The conveyor oven can also include 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. Furthermore, the controller can be able to change the speed of the main blower from first speed to the second speed based at least in part upon the detection of the absence of food in the oven chamber, and can be configured 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.
Some embodiments of the present invention provide a conveyor oven having a cooking mode and an energy saving mode, an oven chamber in which food is cooked, a conveyor moveable to convey the food through the oven chamber, and a first set of one or more burners configured to generate heat for the oven chamber. The first set of one or more burners can be operable at a first intensity during the cooking mode, and can be turned off in the energy saving mode. The conveyor oven can also include a second set of one or more burners configured to generate heat for the oven chamber, 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, 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.
Some embodiments of the present invention provide a conveyor oven having 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 passing therethrough, a blower that circulates air, and a damper adjustable between a first configuration and a second configuration different from the first configuration in order to adjust the gas burner airflow rate.
Other aspects of the present invention will become apparent by consideration of the detailed description and accompanying drawings.
Before any embodiments of the present invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.
In some embodiments, the oven 20 can have one or more sensors positioned to detect the presence of food product on the conveyor 22 at one or more locations along the length of the conveyor 22. By way of example only, the oven 20 illustrated in
The conveyor 22 can be implemented using conventional components and techniques such as those described in U.S. Pat. Nos. 5,277,105 and 6,481,433 and 6,655,373, the contents of which are incorporated herein by reference insofar as they relate to conveyor support, tracking, and drive systems, and related methods. In the illustrated embodiment by way of example only, a chain link drive is housed within compartment 30 at the left end 26 of the oven. Thus, a food item 32R, such as a raw pizza or a sandwich (to be toasted), may be placed on the conveyor 22 of the incoming left oven end 26, and removed from the conveyor 22 as a fully baked food item 32B at the outgoing right oven end 28. The speed at which the conveyor 22 moves is coordinated with the temperature in the heated tunnel 24 so that the emerging food item 32B is properly baked, toasted, or otherwise cooked.
A hinged door 34 is provided on the front of the oven 20 shown in
Although the oven 20 illustrated in
The controller 42 in the illustrated embodiment adjusts the internal temperature of the oven using a PID (proportional-integral-derivative) control module 55 (also described in greater detail below). The PID control module 55 can calculate an amount of fuel needed by the gas burners 100, 150 to raise the actual temperature toward a setpoint temperature, and the CPU 650 can generate a command or signal to an amplifier board or signal conditioner that controls a modulating fuel valve 408 (described below) to regulate the amount of fuel provided to each of the gas burners 100, 150.
Heat delivery systems for supplying heat to the tunnel 24 are described generally in U.S. Pat. Nos. 5,277,105, 6,481,433 and 6,655,373, the disclosures of which are incorporated herein by reference insofar as they relate to heat delivery systems for ovens. As shown diagrammatically in
The configuration of the conveyor oven 20 illustrated in
In some embodiments, the speed of the main blowers 72, 74 may be varied at times to reduce the amount of energy used by the conveyor oven 20 during periods of non-activity. To provide control over fan speed in these and other cases, the main blowers 72, 74 can be driven by variable-speed electric motors (not shown) coupled to and controlled by the controller 42. Power can be supplied to each variable-speed motor by, for example, respective inverters. In some embodiments, each inverter is a variable-speed inverter supplying power to the motor at a frequency that is adjustable to control the speed of the motor and, therefore, the speed of each of the main blowers 72, 74. An example of such an inverter is inverter Model No. MD60 manufactured by Reliance Electric (Rockwell Automation, Inc.). By utilizing variable speed motors supplied by power through respective inverters as just described, a significant degree of control over fan speed and operation is available directly via the controller 42 connected to other components of the control system. A similar motor control arrangement can also be used to control the speed of the combustion blower 155 (described in greater detail below), which functions to provide an appropriate level of air to the burners 100, 150 for proper combustion of fuel supplied to the burners 100, 150.
The main blowers 72, 74 described and illustrated herein can be located at any of a variety of locations with respect to the plenums 68, 70 of the oven 20, and can be used to pull and/or push air with respect to the plenums 68, 70 and/or the tunnel 24. For example, in some embodiments, the main blowers 72, 74 are positioned and oriented to draw air from the tunnel 24 into one of the plenums 68, 70. The suction caused by the main blowers 72, 74 lowers the air pressure in the tunnel 24 and increases the air pressure in the plenums 68, 70, thereby forcing heated air from the plenums 68, 70 into the tunnel 24 through the fingers 76, 78. In other embodiments, the main blowers 72, 74 are oriented to draw heated air from each of the plenums 68, 70 into the tunnel 24 through the metal fingers 76, 78.
An example of an orientation and layout of components in a conveyor oven 20 according to the present invention is shown in
With continued reference to the illustrated embodiment of
The burner 100 illustrated in
The structure of the burner 100 illustrated in
However, the speed of the combustion blower 155 is not the only variable that can affect the efficiency of the flame. The flame can also be adversely (or positively) affected by the speed of the main blowers 72, 74. For example, in some embodiments, the speed of the main blowers 72, 74 can be adjusted to save energy during operation of the oven—a change that can affect the efficiency of the flame. In the illustrated embodiment, the photosensor 79, 81 can be used to detect whether a food item has been placed on the conveyor 22 (see step 300 of
When the timer illustrated in
The temperature of the oven 20 can also affect the rate at which air is circulated through the oven 20, independent or at least partially independent of the speed of the main blowers 72, 74. As the air increases in temperature, the air becomes less dense. Therefore, suction from one oven chamber to another (e.g., suction from an oven plenum to the tunnel, or vice versa) can gradually reduce as air temperature at different locations within the oven 20 increases or decreases. For example, as air temperature within the tunnel 24 of the oven 20 increases in the illustrated embodiment, air pressure within the tunnel 24 increases, thereby reducing the ability of air to move from the burners 100, 150 into the tunnel 24. Accordingly, increased air supply to the burners 100, 150 can be needed in order to maintain an optimal flame.
To address the changing needs of air supply to the burners 100, 150 based at least upon changes in main blower speed 72, 74,
With continued reference to
As described above with reference to
At this point, the controller 42 in the illustrated embodiment has already determined the internal temperature in the oven 20, the flow rate of the modulating fuel valve 408 (described in greater detail below), and the speed of the main blower 72 (or these values are otherwise known or set). The controller 42 then uses this information to determine an appropriate speed for the combustion blower 155 (step 811). This determination can be reached in a number of different manners. In some embodiments, the controller 42 accesses a computer readable memory which stores a look-up table. As illustrated in
The values of variables X1 through X11 and Y1 through Y11 will vary depending upon the size, shape, and configuration of the conveyor oven 20 and, therefore, can be specific to each conveyor oven model utilizing such a look-up table. Furthermore, some embodiments of the look-up table can include additional variables that affect the identified combustion blower speed. For example, in some look-up tables, the combustion blower speed setting can be based upon oven temperature, main blower speed, and the flow rate of the modulating fuel valve 408 associated with the burner.
In other embodiments, the controller 42 determines the appropriate combustion blower speed by calculating a value. By way of example only, the value can be calculated by the controller 42 based at least in part upon the following formula:
Combustion Blower Speed=(A×Gas Flow Rate)−(B×Main Blower Speed)+(C×Oven Temperature)
or by the following alternate formula:
Combustion Blower Speed=(A×Gas Flow Rate)−(B×Main Blower Speed)
or by the following alternate formula:
Combustion Blower Speed=(A×Gas Flow Rate)+(C×Oven Temperature)
wherein A, B, and C are coefficients determined at least in part upon the size, shape, and configuration of the conveyor oven 20 and components of the conveyor oven 20, such as the size and/or shape of the plenum 68, 70, the position of the combustion
wherein A, B, and C are coefficients determined at least in part upon the size, shape, and configuration of the conveyor oven 20 and components of the conveyor oven 20, such as the size and/or shape of the plenum 68, 70, the position of the combustion blower 155 with respect to the fingers 76, 78 and the plenum 68, 70, and the like.
With continued reference to
If no food item is detected on the conveyor 22 and the timer exceeds a predefined threshold (see step 220), the speeds of the main blowers 72, 74 are set to a second or medium speed (see step 224) (or to any other reduced speed). In some embodiments, the intermediate speed of the main blowers 72, 74 is generally considered to be the lowest possible operating speed where the amount of air circulated through the oven by the main blowers 72, 74 is sufficient to maintain the flames 64, 66 of the burners 100, 150 without requiring assistance from the combustion blower 155. In other embodiments, the intermediate speed of the main blowers 72, 74 is higher than this. Furthermore, the temperature setting is decreased (e.g., the output of the modulating fuel valve 408 is set to medium, or otherwise to a lower level in step 228) to correspond with the reduced airflow. In the illustrated embodiment, the controller 42 also attempts to activate the combustion blower 155 at this time (see step 232). Alternatively at this step 232, the speed of the combustion blower 155 can be increased from a lower operating state.
In some embodiments, an air switch or current switch (not shown) may be used to verify that the combustion blower 155 has been activated (see step 236). If the combustion blower 155 has failed to activate, due to malfunction, jamming, and the like, the main blowers 72, 74 and temperature setting (e.g., modulating valve 408) can remain at their corresponding medium settings (see steps 200, 220, 224, 228) until a food item is detected on the conveyor 22. By remaining in the intermediate energy savings mode, the oven 20 is able to save energy (through the reduced blower speed and temperature setting) without compromising the integrity of the flames 64, 66, which could possibly become unstable without the assistance of the combustion blower 155 if the main blower 72, 74 speeds were to be reduced any further.
If the controller 42 detects that the combustion blower 155 has been activated and is running, the speed of the main blowers 72, 74 is set to a third, low setting (see step 240). In other embodiments, the main blowers 72, 74 may be turned off. In some embodiments, the low speed of the main blowers 72, 74 is below the minimum speed required to maintain the flames 64, 66 of the burners 100, 150, and is a speed at which a greater (and in some cases, a maximum) energy savings is achieved. Furthermore, the setpoint temperature is also set to a third, low setting (see step 244) to compensate for the drop of airflow, and provides greater (and again in some cases, a maximum) energy savings. The combustion blower 155 remains running to maintain the integrity of the flames 64, 66 until a food item is detected on the conveyor 22 (see step 252), at which point the combustion fan 155 is deactivated or reduced in speed (see step 216), the main blowers 42, 44 are turned to high or are otherwise increased in speed (see step 208), the timer is reset (see step 204), and the setpoint temperature is returned to high (step 212).
In alternative embodiments of the energy management mode shown in
During operation of the conveyor oven 20, the first embodiment of the fuel delivery system 400 is adjustable between a first operating mode and a second operating mode. More specifically, the controller 42, responsive at least in part to one or more inputs from the conveyor oven 20 (see
In the first operating mode of the fuel delivery system 400 shown in
Furthermore, the modulating valve 408 may be continuously adjusted during either of the first and second operating modes to alter the intensity of the burners 100 as necessary (see
The fuel delivery system 400′ is couplable to a gas input 404′, such as a utility line, supply tank, and the like, and includes a modulating control valve 408′ for regulating the flow of gas therethrough. The fuel delivery system 400′ also includes a first gas supply line 412′ establishing fluid communication between the modulating control valve 408′ and a first set of one or more burners 100A, and a second gas supply line 416′ in parallel to the first gas supply line 412′ and establishing fluid communication between the modulating control valve 408′ and a second set of one or more burners 100B. This second embodiment of the fuel delivery system 400′ also includes a cut-off valve 420′ positioned along the first gas supply line 412′ to interrupt the flow of gas between the modulating valve 408′ and the first set of burners 100A. In other embodiments, the fuel delivery system 400′ may include more than two gas supply lines of either type 412, 416 just described, depending at least in part upon the specific requirements of the oven 20. In other embodiments, both the first and second gas supply lines 412′, 416′ may include a shut-off valve.
During operation of the conveyor oven 20, the second embodiment of the fuel delivery system 400′ is adjustable between multiple operating modes (e.g., three modes, in the illustrated embodiment). More specifically, the controller 42, responsive at least in part to one or more inputs from the conveyor oven 20 (see
In a second operating mode, the modulating valve 408′ is at least partially closed while the cut-off valve 420′ remains open. This configuration restricts the flow of gas to both the first and second set of burners 100A, 100B, resulting in both sets operating at a second, lower intensity (see
In a third operating mode, the modulating valve 408′ is left in a fully-opened or partially-opened state, while the cut-off valve 420′ is closed. As a result, no gas reaches the first set of burners 100A, while gas can flow freely to the second set of burners 100B. As such, the second set of burners 100B can operate at the first, high intensity (or any lower intensity desired), while the first set of burners 100A is extinguished (see
In the illustrated embodiment of
The illustrated conveyor oven 20′ also includes a burner compartment 424′ adjacent the plenum 70′ and the air return 422′. The illustrated burner compartment 424′ is separated from the plenum 70′ and the air return 422′ by a dividing wall 428′, and includes a burner box 432′ to house the burners 100′ of the heat producing system (described above). The burner compartment 424′ may also contain electronics, such as wiring, for the heat producing system, in addition to at least a portion of the fuel delivery system 400, 400′ (see
In the illustrated embodiment of
With continued reference to the illustrated embodiment of
The illustrated air control system 440″ also includes a primary air duct 460″ providing fluid communication between the damper 444″ and a primary air inlet 464″ of the burner box 432″, thereby allowing air to flow therebetween. In the illustrated embodiment, the primary inlet 464″ is positioned proximate the throat end of the burners 100 (see
The air control system 440″ of
Although the air control system 440″ illustrated in
The illustrated air control system 440″ also includes a set of targets 476″ each coupled to and positioned proximate the end of a respective flame tube 130″. The targets 476″ are spaced a distance from the flame tubes 130″ to restrict the flow of flue gasses from the tubes 130″ during operation of the conveyor oven 20″. In some embodiments, the gap between each target 476″ and its corresponding flame tube 130″ may be adjusted to provide an appropriate amount of flow resistance.
In use of the conveyor oven 20″ the illustrated damper 444″ can be variable between cooking and energy savings modes to at least partially adjust the flow of air therethrough (e.g., the gas burner airflow rate). For example, when the damper 444″ is used in combination with adjustable main blowers 42″, 44″, which blowers are capable of producing a suction force in excess of the amount necessary to properly operate the burners 100″, the damper 444″ can be placed in the second configuration when the conveyor oven 20″ is in the cooking mode, and can be variable to the first configuration when the conveyor oven 20″ is in the energy saving mode. As such, during the cooking mode the damper 444″ can at least partially restrict the flow of air through the damper 444″ and into the burner box 432″ to a level suitable for maintaining the flames in each burner 100″. The damper 444″ can be placed in the first configuration during the energy saving mode to reduce the resistance to the airflow through the damper 444″, and to allow air to flow freely into the burner box 432″. This change can be performed in combination with a reduction in operation speed of the main blowers 42″, 44″ to compensate for loss in suction as a result of the lower main blower speeds. Therefore, the operating speed of the main blowers 42″, 44″ can be reduced during the energy saving mode while the gas burner airflow rate remains sufficiently high to maintain the flames of the burners 100″.
In contrast, when the damper 444″ is used with constant speed main blowers 42″, 44″, the damper 444″ can be placed in the first configuration during the cooking mode, and can be adjustable to the second configuration during the energy savings mode. Since the draw or suction of the blowers 42″, 44″ is constant in both the cooking and energy saving modes, the increased resistance from the closed damper 444″ reduces the gas burner airflow rate in the energy savings mode to correspond to a reduced flame in the burners 100.
The embodiments described above and illustrated in the figures are presented by way of example only, and are not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art that various changes in the elements and their configuration and arrangement are possible without departing from the spirit and scope of the present invention as set forth in the appended claims. For example, although a specific type of burner is described above in connection with ovens according to the present invention, the invention can be applied to any type of gas burner system having other types of burners. As another example, the conveyor oven 20 can have any number of combustion blowers 155 corresponding to any number of burners 100, 150, and can have any number of main blower fans 72, 74, all of which can be located anywhere in the oven 20. In such embodiments, the CPU 650 can control operation of the gas burners 100, 150, the combustion blowers 155, and/or the blower fans 72, 74 independently with respect to one another or with respect to other components of the conveyor oven 20, or otherwise.
Claims
1. A gas supply apparatus for a convection conveyer oven, the gas supply apparatus comprising:
- an interior volume for receiving gas, wherein the interior volume comprises a first fluid conduit and a second fluid conduit, and wherein the first fluid conduit is in selective communication with the second fluid conduit;
- a gas inlet in fluid communication with the first fluid conduit;
- a plurality of gas outlets defined in the first and second fluid conduits and positioned to discharge gas from the interior volume, wherein at least one of the gas outlets is positioned to discharge gas from the first fluid conduit and at least one of the plurality of outlets is positioned to discharge gas from the second fluid conduit; and
- a first valve in fluid communication with the first and second fluid conduits and operable to selectively control the flow of gas between the first fluid conduit and the second fluid conduit, wherein the first valve has an first state in which gas received through the gas inlet is supplied to all of the plurality of gas outlets, and a second state in which gas received through the gas inlet is supplied to at least one of the gas outlets and gas is shut off from at least another one of the gas outlets.
2. The gas supply apparatus of claim 1, wherein the first valve is a cut-off valve.
3. The gas supply apparatus of claim 1, further comprising a second valve operable to control the flow of gas through the gas inlet to the first fluid conduit.
4. The gas supply apparatus of claim 3, wherein the second valve is a modulating valve.
5. A gas supply apparatus for a convection conveyor oven, the gas supply apparatus comprising:
- first and second conduit portions collectively defining an interior volume for receiving a gas;
- a gas inlet in fluid communication with the interior volume;
- at least one gas outlet defined in each of the first and second conduit portions, wherein each of the gas outlets is in fluid communication with the interior volume; and
- a first valve in fluid communication with the interior volume and positioned between the gas inlet and the at least one gas outlet defined in the second conduit portion;
- wherein the first valve has an first state in which gas received through the gas inlet is supplied to all of the gas outlets of the first and second conduit portions, and a second state in which gas received through the gas inlet is supplied to the at least one gas outlet of the first conduit portion but is shut off from the at least one gas outlet of the second conduit portion.
6. The gas supply apparatus of claim 5, wherein the first valve is a cut-off valve.
7. The gas supply apparatus of claim 5, further comprising a second valve operable to control the flow of gas through the gas inlet to the first conduit portion.
8. The gas supply apparatus of claim 7, wherein the second valve is a modulating valve.
9. A gas supply apparatus for a convection conveyor oven, the gas supply apparatus comprising:
- an interior volume for receiving gas, wherein the interior volume comprises a first conduit and a second conduit, and wherein the first conduit is in selective fluid communication with the second conduit;
- a gas inlet in fluid communication with the first conduit;
- a first valve operable to control the flow of gas through the gas inlet to the first conduit;
- a plurality of gas outlets defined by the first and second conduits, wherein the plurality of gas outlets are in fluid communication with the interior volume, and wherein one of the plurality of gas outlets is positioned to discharge gas from the first conduit, and at least another of the plurality of gas outlets is positioned to discharge gas from the second conduit; and
- a second valve in fluid communication with the inlet and at least one of the plurality of gas outlets, wherein the second valve has an first state in which gas received through the gas inlet is supplied to all of the plurality of gas outlets, and a second state in which gas received through the gas inlet is supplied to at least one of the gas outlets of the plurality of gas outlets and gas is shut off from at least another one of the gas outlets of the plurality of gas outlets.
10. The gas supply apparatus of claim 9, wherein the first valve is a cut-off valve.
11. The gas supply apparatus of claim 9, wherein the second valve is a modulating valve.
12. A gas supply apparatus for a convection oven having a plurality of burners, the gas supply apparatus comprising:
- a gas inlet;
- at least one gas conduit defining an interior space for supplying gas from the gas inlet to the plurality of gas burners;
- a first gas outlet supplied with gas from the gas inlet, wherein the first gas outlet is disposed in the at least one gas conduit and is positioned to discharge gas from the interior space to one or more of the plurality of gas burners;
- a second gas outlet supplied with gas from the gas inlet, wherein the second gas outlet is disposed in the at least one gas conduit and is positioned to discharge gas from the interior space to one or more of the plurality of gas burners; and
- a first valve in fluid communication with the gas inlet and establishing selective fluid communication between the gas inlet and the second gas outlet, the first valve having an first state in which gas received through the gas inlet is supplied to the first and second gas outlets, and a second state in which gas received from the gas inlet is supplied to the first gas outlet and is shut off from the second gas outlet,
- wherein the first valve separates the first gas outlet from the second gas outlet.
13. The gas supply apparatus of claim 12, wherein the first valve is a cut-off valve.
14. The gas supply apparatus of claim 12, further comprising a second valve operable to control the flow of gas through the gas inlet to the at least one gas conduit.
15. The gas supply apparatus of claim 14, wherein the second valve is a modulating valve.
Type: Application
Filed: Jun 15, 2016
Publication Date: Oct 13, 2016
Inventors: William S. Schjerven, SR. (Schaumburg, IL), Richard H. Van Camp (Aurora, IL), Theodore James Chmiola (Roscoe, IL)
Application Number: 15/183,480