CIMINO, Ottavio (145 Russell Street, Emu Plains, NSW 2750, AU)
CLAIMS:
1. A cooling system for an oven comprising a cooking chamber having a door, a casing surrounding the cooking chamber and a space defined between the cooking chamber and the casing, said cooling system comprising: s a first vent adapted for fluid communication between the space and air external to said space; a fan for drawing the air through the first vent into the space; and an exhaust for selectively exhausting air from the space into a room housing the oven or into a rangehood of the oven based on a predetermined parameter. o 2. A cooling system according to claim 1, wherein the predetermined parameter is the temperature of said room.
3. A cooling system according to claim 1 , wherein the predetermined parameter is the time of year.
4. A cooling system according to any one of the preceding claims, wherein thes exhaust includes an airflow diverter for selectively directing the air from the space into the room housing the oven or into the rangehood of the oven based on said predetermined parameter.
5. A cooling system according to claim 4, wherein the airflow diverter includes two valves, a first of which is adapted to provide for selective fluid communication between a0 downstream side of the fan and the rangehood and a second of which is adapted to provide for selective fluid communication between the downstream side of the fan and a second vent adapted for fluid communication between the room housing the oven and the space.
6. A cooling system according to claim 5, further comprising a controller for5 controlling an actuator for actuating the 1 first and second valves.
7. A cooling system according to claim 6, wherein the controller is responsive to a thermostat.
8. A cooling system according to claim 6 or claim 7, wherein the response of the controller to the thermostat is manually overridable. 0 9. A cooling system according to any one of claims 6 to 8, wherein the actuator is a servo.
10. A cooling system according to any one of claims 5 to 9, wherein the first vent is adapted for fluid communication between the room housing the oven and the space.
11. A cooling system according to claim 10, wherein the first vent is located adjacent a top of the oven door.
12. A cooling system according to claim 11, wherein the first vent is adapted to direct intake air substantially perpendicularly to ventilation apertures in the top of the oven door.
13. A cooling system according to any one of claims 5 to 12, wherein the second vent is located below the oven door.
14. A cooling system according to claim 13, wherein the second vent is adapted to direct exhaust air from said space toward a floor of the room housing the oven when the first valve is closed and the second valve is open.
15. A cooling system according to any one of the preceding claims, further comprising a third vent adjacent a bottom of the oven door for fluid communication between the space and the room housing the oven.
16. A cooling system according to any one of the preceding claims, further comprising a fourth vent for fluid communication between the space and the room housing the oven for cooling electronic controls of the oven.
17. A cooling system according to any one of the preceding claims, wherein the fan is a centrifugal fan.
18. A cooling system according to claim 17, wherein the fan is a backward curved impeller fan.
19. A cooling system according to any one of the preceding claims, wherein the fan has a capacity of around 450m 3 /hr. |
Cooling System for an Oven
Technical Field
The present invention relates to a cooling system for an oven.
The present invention has been developed for use in domestic and commercial ovens for selectively recycling or dissipating oven heat. However, it may also be used in industrial ovens.
Background of the Invention
Known ovens include a cooking chamber that can be heated to around 250°C, or up to around 500°C in the case of pyrolytic ovens. The cooking chamber is generally housed in an insulated casing designed to limit convection of heat generated by use of the cooking chamber to the surrounding environment. The space between the cooking chamber and the external casing is generally cooled using a fan that forces hot air from within the casing out through vents located adjacent the top of the oven door. Known ovens typically include a control panel located directly above the oven door. A disadvantage of known ovens is that the hot air exhausted through the vents can undesirably overheat the surrounding environment, especially during warm weather. Moreover, the location of the vents is often such that they are about the abdominal height of the oven user. Accordingly, a further disadvantage is that it can be uncomfortable for the user to stand in front of the oven, which is often unavoidable due to the need to use stove hotplates that are typically located directly above the oven.
Another disadvantage of known ovens is that hot air exhausted through the vent above the oven door overheats the control panel and can damage sensitive electronic components of the control panel.
Object of the Invention It is the object of the present invention to substantially overcome or at least ameliorate one or more of the above disadvantages.
Summary of the Invention
Accordingly, the present invention provides a cooling system for an oven comprising a cooking chamber having a door, a casing surrounding the cooking chamber and a space defined between the cooking chamber and the casing, said cooling system comprising:
a first vent adapted for fluid communication between the space and air external to said space; a fan for drawing the air through the first vent into the space; and an exhaust for selectively exhausting air from the space into a room housing the oven or into a rangehood of the oven based on a predetermined parameter.
The predetermined parameter is preferably the temperature of said room or the time of year. The exhaust preferably includes an airflow diverter for selectively directing the air from the space into the room housing the oven or into the rangehood of the oven based on said predetermined parameter. More preferably, the airflow diverter includes two valves, a first of which is adapted to provide for selective fluid communication between a downstream side of the fan and the rangehood and a second of which is adapted to provide for selective fluid communication between the downstream side of the fan and a second vent adapted for fluid communication between the room housing the oven and the space. A controller is preferably provided for controlling an actuator for actuating the first and second valves. The controller is preferably responsive to a thermostat. The actuator is preferably a servo.
The first vent is preferably adapted for fluid communication between the room housing the oven and the space. The first vent is preferably located adjacent a top of the oven door. The first vent is preferably adapted to direct intake air substantially perpendicularly to ventilation apertures in the top of the oven door.
The second vent is preferably located below the oven door and is preferably adapted to direct exhaust air from said space toward a floor of the room housing the oven when the first valve is closed and the second valve is open.
A third vent is provided adjacent a bottom of the oven door for fluid communication between the space and the room housing the oven. A fourth vent is preferably provided for fluid communication between the space and the room housing the oven for cooling electronic controls of the oven.
The fan is preferably a backward curved impeller fan. The fan preferably has a capacity of around 450m 3 /hr.
Brief Description of the Drawings
Preferred embodiments of the present invention will now be described, by way of examples only, with reference to the accompanying drawings, in which:
Fig. 1 is a schematic side elevational view of an oven including a first embodiment of a cooling system according to the present invention, shown in a heat recycling mode;
Fig. 2 is an enlarged view of the airflow diverter of Fig. 1 and adjacent components;
Fig. 3 is a schematic side elevational view of the oven of Fig. 1, with the cooling system shown in a heat dissipating mode;
Fig. 4 is an enlarged view of the airflow diverter of Fig. 3 and adjacent components;
Fig. 5 is a schematic side elevational view of an oven including a second preferred embodiment of a cooling system according to the present invention, shown in a heat recycling mode; and Fig. 6 is a schematic side elevational view of the oven of Fig. 5, with the cooling system shown in a heat dissipating mode.
Detailed Description of the Preferred Embodiments
Referring to Figs 1-4 of the drawings, there is shown a first embodiment of a cooling system for an oven 1 comprising a cooking chamber 2 having a triple or quadruple-glazed door 4 with top and bottom ventilation apertures (not shown), a casing 6 surrounding the cooking chamber 2 and a space 8 defined between the cooking chamber 2 and the casing 6. The cooling system comprises first, second, third and fourth vents 12A, 12B, 12C and 12D, each adapted for fluid communication between the space 8 and air external to said space 8 in a room 100 housing the oven 1. The first vent 12A is located adjacent a top of the oven door 4 and is adapted to direct intake air substantially perpendicularly to the top ventilation apertures of the door 4, so as to siphon out hot air from within the door 4 and draw ambient air in through the bottom ventilation apertures of the door 4. The first vent 12A is also positioned so as to pass by an underside of electronic controls 13 and an electronic control panel 13A of the oven 1. The second vent 12B is located below the oven door 4 and is adapted for fluid communication between the room 100 and the space 8. The third vent 12C is located adjacent the bottom of the oven door 4 and feeds air through the door 4 to cool same. The fourth vent 12D is located above the electronic controls 13 and the electronic control panel 13A of the oven 1, such that both sides of the electronic controls 13 and control panel 13A are cooled by a flow of relatively cool ambient temperature air, which provides a thermal buffer between hot convection air rising from the cooking chamber 2 and the temperature sensitive electronic controls 13 and control panel 13 A. A housing (not shown) extends around the electronic controls 13 and slots are provided in the housing, such that movement of air therepast siphons hot air out from within the housing to cool the electronic controls 13.
A backward curved impeller fan 14 is provided at the top rear of the oven 1 for drawing the air through the first vent 12A into the space 8. The fan 14 has a capacity of around 450m 3 /hr and generates a high suction pressure. An exhaust 16 is also provided for exhausting air from the space 8. The exhaust 16 includes an airflow diverter 18 for selectively exhausting air from the space 8 into the room 100 or into a rangehood 20 based on the temperature of the room 100 or the time of year. As best seen in Figs 2 and 4, the airflow diverter 18 includes a first valve 22 adapted to provide for selective fluid communication between a downstream side of the fan 14 and the rangehood 20 and a second valve 24 adapted to provide for selective fluid communication between the downstream side of the fan 14 and the second vent 12B.
The airflow diverter 18 includes a thermostatically responsive controller (not shown) for controlling an actuator, in the form of a servo (not shown), for actuating the first 22 and second 24 valves. The controller (not shown) is also responsive to limit switches (not shown), which define the open and closed positions of the valves 22, 24.
In use, when the controller (not shown) determines that the room temperature or time of year is such as to warrant recycling of heat, the controller controls the actuator to adopt a heat recycling mode, as shown in Figs. 1 and 2, wherein the first valve 22 is closed and the second valve 24 is open. In this mode, when the cooling system 10 is actuated, the fan 14 draws air through the first, third and fourth vents 12 A, 12C and 12D into the space 8, which cools the space 8, the door 4 and the electronic controls. Accordingly, the air drawn into the space 8 becomes heated. Upon encountering the airflow diverter 18, the heated air is redirected around through the space 8 for exhaust through vent 12B, which directs the heated air toward the floor of the room 100 to heat the room. In use, when the controller (not shown) determines that the room temperature or time of year is such as to warrant dissipation of heat, the controller controls the actuator to adopt a heat dissipating mode, as shown in Figs. 3 and 4, wherein the first valve 22 is open and the second valve 24 is closed. In this mode, when the cooling system is actuated, the fan draws air through the first, second, third and fourth vents 12 A, 12B, 12C and 12D into the space 8, which cools the space 8, the door 4 and the electronic controls. Accordingly, the air drawn into the space 8 becomes heated. Upon encountering the airflow diverter 18, the heated air is redirected into the rangehood 20 for external exhaust.
The response of the controller to the thermostat can also be manually overridden to allow the mode of operation of the airflow diverter (eg. recycling mode or exhaust mode) to be chosen manually.
It will be appreciated that the illustrated oven cooling system advantageously provides for recycling of oven heat during cooler ambient conditions and dissipation of oven heat during warmer ambient conditions. Moreover, the configuration of the exhaust 16 is such that, even when recycled, the heated air is directed away from the user's abdomen and toward the floor of the room 100, which serves as a heat sink for storing heat exhausted from the oven 1. A second preferred embodiment of a cooling system for an oven 1 is shown in Figs 5 and 6. The second embodiment shares many features in common with the first embodiment of Figs 1-4, and corresponding reference numerals have been used to indicate features in common having corresponding functions, hi the second embodiment, a generally conical housing 30 is fiuidly connected with exhaust 16 from the oven 1. A non-return valve 34 is provided between the conical housing 30 and the oven 1 to prevent air drawn through the rangehood 20 from passing the valve 34 when the cooling system is operating in a heat recycling mode, as shown in Fig. 5. The valve 34 is biased by gravity toward a closed configuration, as shown in Fig. 5. The conical housing 30 is fluidly connected with the rangehood exhaust tube 36, via a series of openings (no shown) in the lower end of the rangehood exhaust 36. As shown in Fig. 6, during operation of the rangehood fan 38, and when the oven cooling system is operating in a heat dissipating mode, updraft through the rangehood exhaust 36 creates a negative pressure in the conical housing 30, which opens valve 34, and draws hot air F through the oven exhaust 16. The hot air F from the oven exhaust 32 is drawn through the openings (not shown) in the conical housing 30 so as to flow generally upward along the inside periphery of the rangehood exhaust 36. This ensures that the operation of the rangehood 20 is not adversely affected, since the exhaust gases R from the rangehood flow generally centrally through the rangehood exhaust 36, whilst the hot air F drawn from the oven 1 flows therearound.
Whilst the invention has been described with reference to specific embodiments, it will be appreciated that it may also be embodied in many other forms. For example:
• the ambient air intake can be from external ambient air rather than from air in the room 100 housing the oven 1 ;
• fewer or additional vents can be provided; and/or
when operating in a recycling mode, the heated air from the space 8 can be input into a heating system for delivery to other areas of a building.