High yield ventilated gas oven for cookers

Abstract

 This patent application concerns a ventilated gas oven for cookers, consisting of a baking chamber (1) sealed at the bottom by a plate (4) communicating with the burner flame; said bottom plate (4) being characterized by an internal airspace (4a) through which ambient air passes to be drawn by an exhaust fan (6) and forced into the baking chamber (1).

Description

[0001] This design patent application concerns a ventilated gas oven for cookers having a high yield both in terms of the maximum obtainable temperatures and cooking times.

[0002] Contrary to electric ovens which for years have been fitted with internal ventilation systems, there are still relatively few ventilated gas oven models on the market; this is mainly due to the fact that the generation of forced air into the baking chamber of gas ovens causes two fundamental problems, which often can not be resolved adequately.

[0003] The first problem is the risk of accidental extinction of the burner flame while the second problem is the possible alteration of the gas and primary air mixture, namely that utilized for the combustible mixture; this consequently necessitates careful control and set up of the combustion process.

[0004] Ventilated gas ovens currently available on the market do not provide for the input of ambient air, but involve merely the circulation of hot air in the baking chamber by means of a standard exhaust fan which also recycles the air.

[0005] In the case of these ventilated gas oven models there is a significant and immediate decrease of the temperature inside the baking chamber when the recycling fan is activated while a long time is required to reach the operating temperature when the fan is on.

[0006] The purpose of this invention is to design a ventilated gas oven requiring less time to reach the operating temperature and providing higher maximum temperatures, with respect to current models.

[0007] These two requirements have been attained by providing an airspace on the bottom of the baking chamber under which the burner is conventionally positioned.

[0008] The rear side of the airspace communicates with the base of a manifold abutting against the rear wall of the baking chamber, with slots at the centre and at the top which provide access to the baking chamber.

[0009] A centrifugal type fat, is mounted at the back of the oven, whose suction inlet communicates with said manifold while the supply outlet leads to a pressurized chamber whose left and right ends communicate with the interior of the baking cell.

[0010] The bottom of the baking chamber according to this invention consists of two overlying and slightly spaced sheet plates, the bottom plate being in direct contact with the flame of the burner below.

[0011] The bottom plate features a number of slots at the front through which ambient air is drawn and consequently immediately reaches very high temperatures (in the region of approx. 430°C); this very hot air flows into the above manifold from which it is drawn together with a part of the hot air from the baking chamber, by means of the above centrifugal fan which forces into the chamber through the slots designed specifically for this purpose on the sides of the pressurized chamber.

[0012] For major clarity the description of the invention continues with reference to the following tables which are intended for purposes of illustration and not in a limiting sense, where:

• fig. 1 is a cross-section with the vertical symmetrical plane of the ventilated gas oven according to the invention;
• fig. 2 is a cross-section of the oven in question with plane II-II of fig. 1;
• fig. 3 is a cross-section of the oven in question with plane III-III of fig. 1;
• fig. 4 is a cross-section of the oven in question with plane IV-IV of fig. 1.

[0013] With reference to the above drawings, the oven according to the invention consists of a conventional cube shaped baking chamber (1) constructed in box-shaped sheet plate, closed off at the front by a door (2) having a glass window (2a).

[0014] A conventional burner (3) is fitted on the bottom of this chamber (1) whose flames communicate directly with the bottom surface of the overlying plate (4) which seals the bottom of the baking chamber (1).

[0015] In the oven in question, said plate (4) consists of two overlying slightly spaced sheet plates which create a space (4a) between the same into which air flows from beneath through the slots (4b) provided for this purpose along the front edge of the bottom sheet plate.

[0016] At the back, said airspace (4a) leads to a manifold (5) abutting against the internal face of the rear wall (1a) of the chamber (1), for a length equal almost to the width of said wall (1a).

[0017] Said manifold (5) communicates with the interior of the chamber (1) by means of slots (5a) along the top edge and by means of a large circular slot (5b) at the centre.

[0018] The exhaust fan (6) mounted on the back of the rear wall (1a) of the chamber (1) is housed in a pressurized chamber (6a) which extends transversely along the width of the rear wall (1a) and communicates with the interior of the chamber (1) by means of a series of narrow vertical slots (7) on the two sides, on the left and on the right, of said wall (1a).

[0019] The top edge of pressurized chamber (8a) features a pair of ascending pipes (8) for discharging a part of the hot air laden with odours from the food during baking, to the exterior.

[0020] The air, laden with food odours, flows directly from the chamber (1) into pipes (8) through the slots (9) provided for this purpose on the top edge of the rear wall (1a) in the vicinity of the two pipes (8) behind said wall; the air discharged from the pressurized chamber (6a) produces a current of air which helps to draw the air from chamber (1) through the slots (9).

[0021] With reference to the flow lines shown in the above figures, a description is now provided of the cyclic path the ventilated air through the baking chamber (1).

[0022] The hot air from the chamber (1), thanks to the suction of the exhaust fan (6), flows into the manifold (5) via the top slots (5a) and the centre slot (5b) of the manifold, where it mixes with the hot ambient air from the airspace (4a), where, as mentioned previously, the ambient air is drawn through the slots (4b); it is worthy of note that the ambient air reaches the slots (4b) pre-heated thanks to the fact that it passes through the burner (3) housing.

[0023] Enclosed drawings LCC and LIC show the flow lines of the chamber-manifold and airspace-manifold.

[0024] In particular, fig. 2 shows that there are dividing baffles (4c) inside airspace (4a) which provide a zig-zag route for the pipes so as to increase the time the air remains within the airspace and consequently increase its temperature increment.

[0025] The hot air from the chamber (1) and the very hot air from the airspace (4a) are drawn simultaneously by the manifold (5) by means of the exhaust fan (6) which discharges the mixed air into the pressurized chamber (6a), from which most of the hot air mixture can return into the baking chamber through the above slots (7), while the remainder of the mixture flows into the pipes (8) and is then discharged to the exterior.

[0026] Consequently, by referring to the enclosed drawings, it is easier to understand how the scope of the invention has been attained thanks to the introduction of this plate (4) having an airspace (4a) fitted immediately above the burner (3).

[0027] When the ambient air passes through the airspace (4a), it reaches extremely high temperatures, which, after a brief interval, are also attained in the baking chamber. Enclosed drawings CPC and AEI show the flow lines of the pressurized chamber-chamber and ambient air-airspace. Finally, it is worth mentioning that by fitting the oven in question with a switch which changes the revs of the exhaust fan, it is possible to change the speed of the air flow in the airspace (4a) in order to change the air temperature of the air discharged from the airspace and consequently select the required baking times and temperatures.

Claims

1. A high yield ventilated gas oven for cookers consisting of a cube shaped baking chamber (1) constructed in box-shaped sheet plate, sealed at the front by a door (2) with glass window (2a), having a burner (3) at the bottom whose flames communicate directly with the bottom surface of the overlying plate (4) which seals the bottom of the baking cell (1); an oven characterized in that said plate (4) consists of two overlying and slightly spaced sheet plates designed to create an airspace (4a) which at the back leads into a manifold (5) abutting against the internal face of the rear wall (1a) of the chamber (1) and communicates with the interior of the chamber (1) by means of slots (5a) along the top edge and by means of a large circular slot (5b) at the centre; the invention provides an exhaust fan (6), mounted on the back of the rear wall (1a) of chamber (1), which is housed in a pressurized chamber (6a) intercommunicating with the interior of chamber (1) by means of a series of narrow slots (7) in the vicinity of the two sides, on the left and on the right, of said wall (1a); the top edge of pressurized chamber (6a) features a pair of ascending pipes (8) for discharging a part of the hot air, to the exterior and the plate (4) has slots (4b) at the bottom in the vicinity of the front edge.

2. A high yield ventilated gas oven, according to claim 1) characterized in that there are dividing baffles (4c) inside airspace (4a) which provide a zig-zag route for the pipes.

3. A high yield ventilated gas oven according to claim 1) characterized in that chamber (1) communicates with pipe (8) by means of slots (9) along the top edge of the rear wall (1a) in the vicinity of the two pipes (8), behind said wall.

Drawing