Patent Application
20070194003
none
none
The present invention relates generally to ovens using moving air and/or steam to cook food and, more particularly, to a system and method for handling water in combination ovens.
Many ovens include the ability to cook food using steam. For example, combination ovens provide the ability to cook foods using steam, hot-air convection, or both steam and convection. This combination of convection heating with steam provides a system where food can be properly cooked significantly faster than with traditional ovens or even convection ovens alone. As a result, combination ovens have become a vital asset in commercial cooking environments that need to cook food quickly and, often, in large quantities.
Combination ovens employ a motor driven fan to circulate air within a cooking chamber past electrical heating elements or gas heat exchange tubes to perform the convection functionality. To produce steam within the cooking chamber, a pressurized water line injects water into the cooking chamber, for example onto a rotating cup at the center of the fan, near the heating elements to disperse and vaporize the water. A system of this type is described in U.S. Pat. 6,188,045 issued Feb. 13, 2001, entitled: “Combination Oven With Three-Stage Water Atomizer”, assigned to the assignee of the present invention and hereby incorporated by reference. In this regard, combination ovens require access to both electricity and pressurized water supply lines, such as municipal water supply lines.
Internal plumbing within the combination oven receives pressurized water from the plumbing of the kitchen and delivers it into the cooking chamber of the combination oven. As such, the internal plumbing is subjected to at least a portion of the heat generated within the cooking chamber. While modem plumbing techniques are designed to withstand variations in temperatures, the internal plumbing of combination ovens must be able to tolerate a temperature range extending from room temperature to several hundred degrees Fahrenheit (F). Furthermore, the internal plumbing must be able to tolerate this entire temperature range simultaneously during cooking periods because the plumbing fixtures arranged to interface with the kitchen plumbing are surrounded by room temperature conditions, while plumbing fixtures extending into the cooking compartment are surrounded by several hundred degree steam.
As such, a substantial cost of producing a combination oven is incurred in creating an internal plumbing system that is suited to these operating conditions. For example, considerable engineering design and manufacturing expertise is utilized to create internal plumbing systems for combination ovens that have a minimal number of joints and seals because such interfaces are negatively impacted by wide temperature variations.
Additionally, when including or incorporating a combination oven into a kitchen, the cost of purchasing the combination oven as well as the cost of providing the resources necessary to operating the combination oven (i.e. electricity and pressurized water connections) must be considered. In some cases, the cost of these resources may significantly impact the decision to include a combination oven within a kitchen.
The cost and complexity of installing a combination oven is at least one reason that combination ovens have only been widely adopted in large commercial kitchens and have not gained significant adoption in smaller commercial kitchens and consumer or home kitchens. In particular, it is widely recognized that plumbing costs account for a substantial amount of kitchen building expenses. This is generally true in both new construction, but can be particularly true when remodeling. As such, the decision to incorporate a combination oven into a kitchen, particularly a previously completed kitchen, may be relatively costly and outside of the budget for small commercial and/or residential kitchens.
Accordingly, it would be desirable to have a system and method to reduce the costs associated with ovens employing steam and, in particular, plumbing costs associated with such ovens. More specifically, it would be desirable to have a system and method for reducing the manufacturing costs associated with internal plumbing systems of ovens employing steam as well as for reducing the installation plumbing costs associated with incorporating such an oven into a kitchen.
The present invention overcomes the aforementioned drawbacks by providing a system and method for providing an oven with water without the need for extensive internal plumbing or pressurized water supplies. Specifically, the present invention includes a passive water supply system that is caused to draw water from an external reservoir in response to a low pressure area created by rotation of a fan within a cooking chamber of the oven. In this regard, the fan creates the force necessary to draw water into the oven, atomizes the water by drawing it into the rotating blades of the fan, and circulates the atomized water along with the air in the cooking compartment.
In accordance with one aspect of the invention, an oven is disclosed that includes a housing defining an interior cooking compartment for holding food at an elevated temperature. A fan is positioned adjacent to a wall of the housing to circulate air and water within the cooking compartment during a cooking process. Additionally, the fan provides an air flow region between the fan and the wall. A water supply line extends from an exterior of the housing through the wall at a point behind the fan to deliver water to the air flow region between the fan and the wall to be dispersed by the fan before passing into the cooking compartment. Accordingly, the water supply line length in the cooking compartment may be minimized.
In accordance with another aspect of the invention, an oven is disclosed that includes a housing forming a cooking compartment defining an interior of the oven. A water supply line extends through the housing to position an end of the water supply line within the cooking compartment. A fan is arranged within the cooking compartment near the end of the water supply line to create a low pressure area at the end of the water supply line to draw water into the cooking compartment from an external reservoir.
In accordance with yet another aspect of the invention, a method of operating an oven is disclosed that includes energizing a heating element configured to heat an enclosed cooking compartment of the oven. The method also includes rotating a fan to circulate air within the cooking compartment. Accordingly, a low pressure area is created that surrounds a water supply passage extending from a reservoir of water into the cooking compartment and that draws the water through the water supply passage into the cooking compartment to generate steam from the water.
Various other features of the present invention will be made apparent from the following detailed description and the drawings.
Referring now to
In operation, a user places food within the cooking compartment 14 via oven door 12 and enters the desired cooking parameters through the user interface 16. Responsive thereto, electricity is drawn from the electrical connection 18 and water is drawn from the water supply system 20 to generate the heat and steam necessary to carry out the desired cooking process.
Referring now to
The plates 28, 32 also include central holes 36, 38 designed to be coaxially aligned along the axis 33 to receive a drive shaft 40 connected to a motor 42. In this regard, the motor 42 can rotate the drive shaft 40 to thereby rotate the fan 26.
The motor 42 is positioned outside the housing 11 with only the drive shaft 40 passing through a vertical wall of the housing 11 protecting the motor from high temperatures within the cooking compartment 14. According to one embodiment, the fan 26 is positioned within a few inches of the wall 11.
When the fan 26 is mounted on the drive shaft 40, a first end 44 of the water supply line 24 may pass through the wall of the housing 11 behind the fan 26 so that the first end 44 of the water supply line 24 is located proximate to the first plate 28 of the fan 26 having the plurality of holes 30 formed therein. In this way, only a short length of the water supply line 24 needs to extend into the cooking compartment 14 and no pipe fitting such as elbows and the like are positioned within the cooking compartment 14. It is contemplated that the first end 44 of the water supply line 24 may be near and generally parallel to the motor drive shaft 40. A second end 46 of the water supply line 24 is submerged in a supply of water 48 held in the reservoir 22.
Referring now to
Referring now to
Therefore, a system and method for delivering water into a oven is provided without the need for plumbing connections to pressurized water supplies, such as municipal water supplies. Furthermore, by arranging the convection fan 26 of the oven 10 within close proximity of a wall 11 of the cooking chamber 14 and arranging one end 44 of the water supply line 24 within that wall 11 near the fan 26, a low pressure area 50 can be created that will be capable of drawing water from the external reservoir 22 into the cooking compartment 14.
Therefore, the above-described system and method advantageously removes the need for connections to pressurized water sources. However, it is contemplated that a pump, though not required, may be included to draw the water from a remotely located reservoir and deliver the water to a position adequate to then be drawn by the low pressure area into the cooking compartment of the oven, for example a combination oven.
By removing the need for connections to pressurized water sources, the internal plumbing systems required for receiving pressurized water and delivering it into the cooking compartment is advantageously removed and manufacturing costs are reduced. Furthermore, by utilizing a significantly simplified and cost effective water supply system, a combination oven can be created that is easily incorporated into a kitchen. That is, referring again to
Therefore, a system and method is provided for supplying water to an oven without the need for pressurized water supply lines and associated plumbing systems. Rather, a passive water supply system is used that draws water from an external reservoir in response to the creation of a low pressure area within a cooking chamber of the oven generated by rotation of a fan. In this regard, the fan creates the force necessary to draw water into the oven, atomizes the water by drawing it into the rotating blades of the fan, and circulates the atomized water along with the air in the cooking compartment. Hence, a highly efficient and cost effective combination oven can be created.
It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein, but include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims.
