Impingement/convection/microwave oven and method

Abstract

A combination oven that is operable with convection air, impingement air and microwave energy in various combinations thereof. The oven has an oven chamber and a fan box that are located front to back. A fan in the fan box circulates heated air by discharging via openings in a top and a bottom and taking in via an intermediate opening of a baffle plate. Impingement plates are easily installed and removed in the oven chamber to provide impingement air upwardly or downwardly. At least one of the impingement plates is installed and removed by a sliding motion. Microwave energy is provided through the side walls of the oven chamber.

What is claimed is: 
     
         1 . A combination oven comprising:
 an oven chamber comprising a plurality of walls, one of said walls being vertical and comprising a baffle plate;   a fan disposed in a fan box to circulate heated air between the fan box and said oven chamber via said baffle plate;   at least one impingement air generator that is disposed in said oven chamber and that comprises a removable impingement plate that converts at least a portion of said circulating air to (a) an impingement mode, wherein columns of impingement air flow substantially in a vertical direction within said oven chamber toward a food product when said removable impingement plate is disposed within said oven chamber, and (b) a convection mode when said removable impingement plate is removed from said oven chamber;   a microwave generator disposed to provide microwave energy into said oven chamber via at least one of said walls of said oven chamber; and   a controller that operates said oven in at least one mode selected from the group consisting of: a microwave mode, said convection mode, said impingement mode, a combination microwave and impingement mode, and a combination microwave and convection mode.   
     
     
         2 . The oven of  claim 1 , wherein said wall by way of which said microwave energy is provided is vertical. 
     
     
         3 . The oven of  claim 1 , wherein said wall by way of which said microwave energy is provided is a back wall or a side wall. 
     
     
         4 . The oven of  claim 1 , wherein said microwave generator provides said microwave energy via two walls of said plurality of walls of said oven chamber. 
     
     
         5 . The oven of  claim 1 , wherein said impingement air generator further comprises a blower and an air heater. 
     
     
         6 . The oven of  claim 1 , wherein said removable impingement plate is disposed near a bottom wall of said plurality of walls of said oven chamber so that said impingement air flows upwardly. 
     
     
         7 . The oven of  claim 1 , wherein said removable impingement plate is disposed near a top wall of said plurality of walls of said oven chamber so that said impingement air flows downwardly. 
     
     
         8 . The oven of  claim 6 , wherein an additional impingement plate is disposed near a top wall of said plurality of walls of said oven chamber so that another portion of said circulating air is converted to impingement air that flows downwardly. 
     
     
         9 . The oven of  claim 4 , wherein said two walls are opposite from one another, and wherein said microwave facility comprises one or more microwave generators and one or more wave guides to provide said microwave energy. 
     
     
         10 . The oven of  claim 8 , wherein said microwave generator also provides microwave energy into said oven chamber via an opposite wall of said plurality of walls of said oven chamber, and wherein said microwave generator comprises one or more magnetrons and one or more wave guides to provide said microwave energy. 
     
     
         11 . The oven of  claim 1 , wherein said removable impingement plate has a handle to facilitate installation and removal by a sliding motion. 
     
     
         12 . The oven of  claim 1 , wherein said removable impingement plate comprises a front and opposed sides separated by a wall that contains an array of jet holes shaped to provide said impingement air. 
     
     
         13 . The oven of  claim 12 , wherein said removable impingement plate further comprises a handle to facilitate installation and removal by a sliding motion. 
     
     
         14 . The oven of  claim 13 , wherein said removable impingement plate is installed substantially flush with said baffle plate to receive circulating air from said fan box, and wherein said removable impingement plate comprises a diverter to provide a substantially uniform pressure to said jet holes, whether located near or remote from said baffle plate. 
     
     
         15 . The oven of  claim 1 , further comprising an oven rack disposed in said oven chamber, wherein said baffle plate comprises at least one first opening located below said oven rack, at least one second opening located above said oven rack and near a top of said baffle plate, and one or more third openings located below said first openings, and wherein said circulating air flows from said fan box to said oven chamber via said second and third openings and returns to said fan box via said first opening. 
     
     
         16 . A system for cooking a food product comprising:
 an oven chamber that comprises a plurality of walls, one of said walls being vertical and comprising a baffle plate;   an oven rack disposed in said oven chamber to hold a metal pan that contains the food product;   a microwave generator that provides microwave energy into said oven chamber via at least one vertical wall of said plurality of walls of said oven chamber to rapidly cook said food product;   a fan disposed in a fan box to circulate heated air between the fan box and said oven chamber via said baffle plate;   an impingement air generator that comprises a removable impingement plate that converts at least a portion of said circulating air to (a) an impingement mode, wherein columns of impingement air flow substantially in a vertical direction in said oven chamber toward said food product when said removable impingement plate is disposed within said oven chamber, and (b) a convection mode when said removable impingement plate is removed from said oven chamber; and   a controller that operates said oven in at least one mode selected from the group consisting of: a microwave mode, said convection mode, said impingement mode, a combination microwave and impingement mode, and a combination microwave and convection mode.   
     
     
         17 . The system of  claim 16 , wherein said microwave generator includes a microwave source that provides said microwave energy into said oven via a feed aperture in said vertical wall, and wherein said food rack is located below said feed aperture so as to minimize microwave energy incident to said feed aperture that is reflected by said metal pan, thereby prolonging the longevity of said microwave source. 
     
     
         18 . The system of  claim 17 , wherein said vertical wall is a side wall of said oven chamber. 
     
     
         19 . The system of  claim 18 , wherein said microwave generator also provides said microwave energy into said oven chamber via an opposite side wall of said plurality of walls. 
     
     
         20 . The system of  claim 16 , further comprising a cooling fan that cools the microwave generator, wherein said controller also regulates a speed of said cooling fan based on a temperature sensed by a probe in a vicinity of the microwave facility to reduce the speed as the sensed temperature falls and to increase the speed as the sensed temperature rises. 
     
     
         21 . The system of  claim 16 , further comprising an oven rack disposed in said oven chamber, wherein said baffle plate comprises at least one first opening located below said oven rack, at least one second opening located above said oven rack and near a top of said baffle plate, and one or more third openings located below said first opening, and wherein said circulating air flows from said fan box to said oven chamber via said second and third openings and returns to said fan box via said first opening.