Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3626922 A
Publication typeGrant
Publication dateDec 14, 1971
Filing dateFeb 2, 1970
Priority dateJan 31, 1969
Also published asDE2003530A1, DE2003530B2, DE2003530C3
Publication numberUS 3626922 A, US 3626922A, US-A-3626922, US3626922 A, US3626922A
InventorsBorge Donald Richard
Original AssigneeGas Council
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Forced convection oven
US 3626922 A
Images(1)
Previous page
Next page
Description  (OCR text may contain errors)

United States Patent Inventor Donald Richard Borge London, England Appl. No. 7,684 Filed Feb. 2, 1970 Patented Dec. 14, 1971 Assignee The Gas Council London, England Priority Jan. 31, 1969 Great Britain 5,403/69 FORCED CONVECTION OVEN 3 Claims, 2 Drawing Figs.

US. Cl 126/21 A Int. Cl F24c 15/32 Field olSearch 126/19, 21, 21 A, 39 C, 273

[56] References Cited UNlTED STATES PATENTS 2,524,272 10/1950 Sage 126/21 A UX 2,817,506 12/1957 Albright 126/21 A UX 3,384,068 5/1968 Perry et a1. 126/21 A 3,411,493 11/1968 Everson et a1. 126/21 A 3,463,138 8/1969 Lotter et a1. 126/21 A Primary Examiner-Charles J. Myhre AnorneyLarson and Taylor ABSTRACT: A gas fired forced convection oven comprises a heating or cooking zone, fan means for circulating a hot gaseous atmosphere in said zone, the gas distribution means including at least one fuel gas burner located in a passage lead ing to said zone, a throat located in the passage downstream of said burner and means for deflecting the circulating atmospheric gas issuing from said fan away from said burner and into said throat whereby the circulating atmospheric gas mixes with the combustion gases from the burner and enters the said heating or cooking zone.

FORCED CONVECTION OVEN BACKGROUND OF THE INVENTION This invention relates to forced convection ovens and is particularly concerned with gas fired ovens of this type. Such ovens are conventionally used to heat a number of separate containers or portions of precooked foods but the ovens may also be used for normal cooking purposes if required. A desirable characteristic of this form of oven is uniform heating throughout the oven space and such uniformity is obtained by controlling the temperature, quantity and flow patterns of the circulating medium.

In the present forms of gas heated convection oven the circulating medium is generally air heated indirectly by some form of heat exchanging system, the combustion products from the gas burners being vented to atmosphere. This arrangement tends towards operating inefficiency and adds considerably to the manufacturing and running costs.

It is therefore an object of the present invention to provide an improved form of gas fired forced convection oven in which the aforementioned disadvantages are minimized.

SUMMARY OF THE INVENTION According to the invention a forced convection oven comprises a heating or cooking zone, fan means for circulating a hot gaseous medium in said zone, the gaseous medium distribution means including at least one fuel gas burner located in a passage leading to said zone, a pressure reducing throat located in the passage downstream of said burner and means for deflecting the circulating gaseous medium issuing from said fan away from said burner and into said throat whereby the circulating medium mixes with the combustion gases from the burner and enters the said heating or cooking zones.

in a preferred arrangement the circulating medium enters the heating or cooking zone through apertured side panels flowing substantially horizontally across the cooking zone and leaves via an apertured rear panel. The fan may be located in a compartment positioned below the heating or cooking zone.

To enable the nature of the invention to be more readily understood, one embodiment of the invention will now be described, solely by way of example, with reference to the accompanying drawing, which shows diagrammatically a preferred form of oven. In the drawing:

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a midsectional side view of the oven and FIG. 2 is a midsectional view looking from the front of the oven.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing a forced convection gas fired oven comprises a heating or cooking zone 1 having perforated side plates 2 through which a hot gaseous medium comprising a mixture of air and combustion products from the fuel burners used to heat the oven, is supplied by means of a fan 3. The fan is located in a distribution chamber 4 positioned below the heating or cooking space and circulates the gaseous medium to the side plates via a supply duct 5 at each side of the oven.

The side plate apertures 6 are arranged and dimensioned to provide a substantially uniform flow of gas across the heating or cooking zone and the gas is withdrawn from the oven zone through an apertured back plate 10 and returned to the distribution chamber and fan via an extract duct 7. The fan is driven by an electric motor 8.

The oven is heated by fuel gas burners 9 positioned at each side of the appliance, the burner ports in each case being arranged to fire directly upwards into a lower extension of the supply duct 5. A pressure reducing throat I1 is fonned at the lower end of each duct 5 and deflector or baffle plates 12, associated with the distribution chamber 4, are arranged to shield the burners and direct the gaseous medium circulated by the fan 3 into the throat where the circulating gaseous medium mixes thoroughly with the combustion gases from each burner.

It will be appreciated that the pressure reducing throat is shaped as a venturi or orifice tube to cause a sharp rise in the velocity of the circulating medium which together with an associated drop in the static pressure within the throat enables the combustion products to enter the side ducts 5 without down draughts efi'ecting the burner or burners situated below the deflector plate 12.

The oven is provided with a vent or flue (not shown) connecting with the extract duct 7 at a point where the internal pressure is only slightly positive in relation to atmospheric pressure, such that natural aspiration prevents a build up of excess combustion products within the oven.

During comparative tests it was shown that this form of direct fired forced convection oven provides a considerable advantage in both efficiency and thermal response times over the conventional and previously known forms of oven.

I claim:

1. A forced convection oven comprising an openable chamber defining a cooking zone; fan means located in a compartment positioned below the cooking zone; inlet and outlet passageways between said compartment and the cooking zone for circulating a gaseous medium through said zone; gas fuel burners positioned at each side of the oven for heating the gaseous medium; said burners including ports arranged to fire directly upwards into the inlet passageways leading to the oven cooking zone; a pressure reducing throat within each inlet passageway and a deflector plate in each inlet passageway for shielding the burners and directing the gaseous medium circulated by the fan into the throat so that the circulating gaseous medium mixes with the combustion gases from each burner before passing into the cooking zone.

2. A forced convection oven according to claim 1 wherein the gaseous circulating medium comprises a mixture of air and combustion products from the fuel burner.

3. A forced convection oven according to claim 2 wherein the openable chamber includes top, bottom, back and side walls, said side walls including apertured panels therein and said back wall including an apertured panel therein, said oven further comprising means for directing the circulating medium into the cooking zone through the apertured panels in the side walls of the chamber so that, in operation, the medium flows substantially horizontally across the cooking zone and exits through the apertured panel in the back wall of the chamber.

t i l i

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2524272 *Aug 22, 1946Oct 3, 1950Steiner Ives CoDirect gas-fired oven
US2817506 *Jul 23, 1954Dec 24, 1957Albright Edward AOven construction
US3384068 *Dec 9, 1966May 21, 1968American Gas AssGas oven system
US3411493 *Jul 24, 1967Nov 19, 1968G R Everson And Sons LtdForced air oven
US3463138 *Apr 29, 1968Aug 26, 1969South Bend Range CorpConvection oven
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3698377 *May 7, 1971Oct 17, 1972Hoover CoGas-fired forced convection ovens
US3831579 *Aug 16, 1971Aug 27, 1974Rinnai KkForced hot air type cooking oven
US3847134 *Mar 1, 1973Nov 12, 1974Tom S O Catering Equipment LtdOvens
US4109636 *Dec 22, 1976Aug 29, 1978British Gas CorporationForced convection ovens
US4226178 *Jan 29, 1979Oct 7, 1980Rowenta-Werke, GmbhHot-air grills
US4373504 *Dec 22, 1980Feb 15, 1983Raytheon CompanyGas burner convection oven
US4471750 *May 19, 1982Sep 18, 1984Mastermatic, Inc.Tunnel heater
US4762981 *Mar 6, 1987Aug 9, 1988Carlo Erba Strumentazione S.P.A.Heating device in particular for automatic samplers
US4829158 *Jan 6, 1988May 9, 1989Sunbeam CorporationPortable electric oven utilizing recirculating high speed air for cooking
US5620623 *Jan 26, 1996Apr 15, 1997Whirlpool CorporationThermal blend convection oven
US6615819Mar 10, 2000Sep 9, 2003General Electric CompanyConvection oven
US6847013 *Feb 10, 2003Jan 25, 2005Metal Masters FoodserviceHeated proofing cabinet
US7784457Dec 29, 2004Aug 31, 2010Levent AkdagOven
US8574680Dec 30, 2010Nov 5, 2013International Business Machines CorporationMaterials and methods for immobilization of catalysts on surfaces and for selective electroless metallization
Classifications
U.S. Classification126/21.00A
International ClassificationF24C15/32
Cooperative ClassificationF24C15/322
European ClassificationF24C15/32B
Legal Events
DateCodeEventDescription
Mar 9, 1988ASAssignment
Owner name: BRITISH GAS PLC, RIVERMILL HOUSE 152 GROSVENOR ROA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:BRITISH GAS CORPORATION;REEL/FRAME:004859/0891
Effective date: 19870512
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:BRITISH GAS CORPORATION;REEL/FRAME:004859/0891
Owner name: BRITISH GAS PLC, ENGLAND