Domestic oven

Abstract

A domestic gas-fired oven having a top burner in the cooking cavity and a bottom burner fully concealed beneath the bottom of the cavity. The heated products of the bottom burner are caused to flow in a wrapper over the bottom and partially over the side walls to openings in the latter where these products enter the cavity. Air under pressure is supplied to the burners by a fan and another fan withdraws flue products from the top of the cavity, with the incoming air and the exhaust flowing through different sections of a rotating regenerator wheel for heat transfer therebetween. The burners can be operated separately for broiling and baking and together for high temperature self-cleaning of the oven.

I, therefore, particularly point out and distinctly claim as my invention: 
     
       1. A domestic oven comprising a liner forming a cooking cavity having top, bottom, side and rear walls, the bottom walls being substantially smooth and imperforate, broiler burner means mounted in the upper portion of said cavity, with the top wall thereabove having an opening for exhaust of the cavity, bake burner means disposed exteriorly of the cavity, means for delivering combustion air under pressure selectively to either the broiler or bake burner or both, means for circulating the heated products from the bake burner in operation over exterior surfaces of the bottom and side walls, the latter being provided with openings for inflow of such heated products to the cavity and exhaust therefrom through the top wall opening, and means for directing the flue products from such top wall opening to a remote discharge. 
     
     
       2. A domestic oven comprising a liner forming a cooking cavity having top, bottom, side and rear walls, the bottom wall being substantially smooth and imperforate, broiler burner means mounted in the upper portion of said cavity, with the top wall thereabove having an opening for exhaust of the cavity, bake burner means disposed exteriorly of the cavity, means for circulating the heated products from the bake burner in operation over exterior surfaces of the bottom and side walls, the latter being provided with openings for inflow of such heated products to the cavity and exhaust therefrom through the top wall opening, means for directing the flue products from such top wall opening to a remote discharge, and means for delivering ambient air to at least one burner in heat exchange relationship to the flue products withdrawn from the cavity. 
     
     
       3. A domestic oven comprising a liner forming a cooking cavity having top, bottom, side and rear walls, the bottom wall being substantially smooth and imperforate, broiler burner means mounted in the upper portion of said cavity, with the top wall thereabove having an opening for exhaust of the cavity, bake burner means disposed exteriorly of the cavity, means for circulating the heated products from the bake burner in operation over exterior surfaces of the bottom and side walls, the latter being provided with openings for inflow of such heated products to the cavity and exhaust therefrom through the top wall opening, means for directing the flue products from such top wall opening to a remote discharge, and means for delivering ambient air under pressure selectively to one or both of the broiler and bake burners in heat exchange relationship to the flue products exhausted from the cavity. 
     
     
       4. A domestic oven comprising a liner forming a cooking cavity having top, bottom, side and rear walls, the bottom wall being substantially smooth and imperforate, broiler burner means mounted in the upper portion of said cavity, with the top wall thereabove having an opening for exhaust of the cavity, bake burner means disposed exteriorly of the cavity, blower means for causing ambient air to flow to the burners under a pressure differential, flow-regulating means for directing such ambient air flow substantially fully to either the broiler or bake burner, respectively for broiling and baking operations, or dividing the flow between the two burners for joint operation thereof at a relatively high-temperature self-cleaning cycle, means for circulating the heated products from the bake burner in operation over exterior surfaces of the bottom and side walls, the latter being provided with openings for inflow of such heated products to the cavity and exhaust therefrom through the top wall opening, and means for directing the flue products from such top wall opening to a remote discharge. 
     
     
       5. A domestic oven comprising a liner forming a cooking cavity having top, bottom, side and rear walls, the bottom wall being substantially smooth and imperforate, broiler burner means mounted in the upper portion of said cavity, with the top wall thereabove having an opening for exhaust of the cavity, bake burner means disposed exteriorly of the cavity, first fan means for delivering ambient air under pressure to at least one burner, means for circulating the heated products from the bake burner in operation over exterior surfaces of the bottom and side walls, the latter being provided with openings for inflow of such heated products to the cavity and exhaust therefrom through the top wall opening, and second fan means for withdrawing the flue products from the cavity through the top exhaust opening thereof to a remote discharge. 
     
     
       6. An oven as set forth in claim 5, including an electric motor commonly driving the first and second fan means in counter-rotating relation. 
     
     
       7. An oven as set forth in claim 6, including means for bringing the ambient air delivered by the first fan means into heat exchange relationship to the flue products exhausted by the second fan means. .Iadd. 8. The method of heating the walls of a baking oven for the heat cleaning of soils from the interior wall surfaces of both an oven liner and an access door defining an oven cooking cavity which includes soils accumulated thereupon during the previous carrying out in said oven cavity of normal food cooking operations in the normal food cooking temperature range; said method comprising generating flue gases by a gas burner located in a fire box beneath the bottom of the oven liner, directing the flue gases up around the opposite sides of the oven liner and across the top of the oven liner and then down the back portion of the oven liner, passing the flue gases over a heat exchanger surface and then exhausting the flue gases to the atmosphere, while at the same time passing relatively cool ambient air over the exchanger surface so as to use the heat from the flue gases to heat the ambient air, then supplying the heated air as preheated secondary air for the gas burner, whereby the heat recovered from the flue gases lowers the exhaust temperature of the flue gases to the temperature range between about 300°   F. and 550°  F. and also increases the efficiency of combustion of the gas burner, so as to reduce the consumption of fuel and hence the amount of the exhaust gases and the total heat in the exhaust gases. .Iaddend. .Iadd. 9. A self-cleaning gas cooking oven comprising an oven body supporting a box-like oven lineer and a front-opening access door which define an oven cooking cavity, a fire box disposed beneath the bottom wall of the oven liner, a gas burner located within the fire box, heating channels extending up to the opposite side walls back across the top wall and down the rear wall of the oven liner and communicating with the fire box so that convection currents of flue gases from the burner may pass through the channels thereby heating the walls forming the oven cooking cavity, a vertically arranged stationary heat exchanger located adjacent at least one of the heating channels, a flue gas inlet at the bottom of the heat exchanger, and a flue gas outlet at the top of the heat exchanger, an ambient air inlet at the top of the heat exchanger and an ambient air outlet at the bottom of the heat exchanger, said ambient air outlet supplying heated air to the fire box as pre-heated secondary air for the burner, whereby the flue gases flowing through the heat exchanger give up much of their heat to the ambient air. .Iaddend.