WO2010037657A1

WO2010037657A1 - Cooking appliance

Info

Publication number: WO2010037657A1
Application number: PCT/EP2009/062201
Authority: WO
Inventors: Hubert Giraud; Horst Kutschera; Thomas Rauch; Martin Strasser
Original assignee: BSH Bosch und Siemens Hausgeräte GmbH
Priority date: 2008-09-30
Filing date: 2009-09-21
Publication date: 2010-04-08
Also published as: DE102008042485A1

Abstract

The invention relates to a cooking appliance, in particular a vegetable oil stove, comprising a burner unit (2) for producing an open flame by the combustion of a liquid fuel, and a connecting piece (32) which is arranged between the burner unit and a fuel tank. In order to operate the cooking appliance in a safe manner, the connecting piece (32) comprises an anti-return valve (70) which prevents the fuel from flowing from the burner unit (2) in the direction of the fuel tank.

Description

cooker

The present invention relates to a cooking appliance, in particular vegetable oil cooker according to the preamble of claim 1.

From DE 101 61 154 a burner for a liquid fuel operated stove, preferably for a vegetable oil cooker is known. The burner is provided with an evaporator, which is connected to a feed pipe for the fuel. The evaporator is provided with a gas outlet channel, which is directed to a baffle device for the gas / air mixture.

The fuel used is primarily vegetable oil, which can be used as a fuel in camping and outdoor areas and is also available in tropical and subtropical countries. For example, palm oil, coconut oil, sunflower oil, etc. come into consideration as vegetable oil. However, the cooking appliance is designed so that as fuel petroleum, diesel oil, gasoline and vegetable oil esters come into question.

However, cooking appliances burning fuel for vegetable oil have special requirements, which are due to the physical properties of the fuel. Vegetable oil evaporates only at about 220 ⁰ C, which means that the evaporation temperature of vegetable oil over, for example, kerosene is about 165 ⁰ C higher. Due to this higher evaporation temperature of the vegetable oil special pre-heaters for the evaporator are required. During operation, the temperature in the evaporator of the cooking appliance must not be too high, otherwise the formation of deposits inside the evaporator will be promoted. Even under optimum operating conditions residues form in the evaporator, which is why a cleaning option of the evaporator for the trouble-free operation of the cooking appliance is necessary. For these reasons, for example, a kerosene stove is not suitable for use with vegetable oil. Rather, cooking appliances must be provided for the combustion of vegetable oil, which are suitable because of their special training, such as the geometry of the evaporator assembly. The object of the present invention is in particular to provide a cheap cooking appliance, which can be operated safely.

This object is achieved by a cooking appliance according to claim 1. The dependent claims relate to preferred embodiments, which can be used individually or in combination with each other.

The invention relates to a cooking appliance, in particular vegetable oil cooker, with a burner unit for generating an open flame by combustion of a liquid fuel, and with a connecting part, which is arranged between the burner unit and a fuel tank.

It is proposed that the connecting part comprises a check valve which prevents fuel flow from the burner unit in the direction of the fuel tank. The advantage of such a cooking appliance is in particular that, in particular, a pulsation of the burner unit during the firing process is avoided.

The connecting part, in which the check valve is formed, may for example be formed by:

a socket of the burner unit (see exemplary embodiment), a line piece between a valve and the burner unit,

- a valve,

a pipe section between a tank and a valve,

- a pipe connection to a tank or

a pipe section inside a tank, e.g. a suction or riser.

An advantageous development provides that a closure element of the check valve is biased by its gravity in the closing direction. This allows a separation of the oil flow by simple means. Preferably, the closure element is designed as a ball, which is arranged in a portion located in the connection part of a fuel channel. The ball-receiving part of the fuel channel has the shape of an inverted cone or a funnel, which receives the ball. Preferably, a spring is provided, which biases the closure element in the closing direction. The use of a spring has the advantage that in addition to the gravity of the closure element, a spring force is generated by the spring, which also acts on the closure element. This spring force can be rectified to the gravity of the closure element. However, due to the use, it is not excluded to provide other types of receptacles for the closure element in the connection part. Thus, for example, a connecting part may be designed such that the part of the fuel channel receiving the closing element has the shape of a laterally directed funnel in which the closing element is held by the spring.

In an advantageous development, it is provided that a filter, in particular a sintered filter, is provided. This prevents the penetration of dirt particles from the oil into the burner unit.

Preferably, the filter is connected downstream of the check valve. This contributes to securing the function of the check valve, since the penetration of combustion residues from the burner unit is prevented in the check valve.

An advantageous development provides that the filter is designed as a captive for the closure element of the check valve. Thus, a captive is made possible by simple means, and it can be dispensed with additional securing means. As a result, the check valve can be produced particularly inexpensively.

A further advantageous embodiment provides that the filter at least partially has an external thread which can be screwed into a corresponding internal thread of a bore of the connecting part. This makes it possible to mount the filter with simple means on the connecting part.

Preferably, the filter is designed as a throttle device for increasing the flow resistance of the fuel. Thus, for example, jet flames can be avoided. Preferably, the filter has recesses for applying a torque. The recesses may be formed, for example, as slots for receiving a screwdriver. This allows the filter to be mounted quickly and easily in the hole provided.

An advantageous development provides that the connecting part is mounted in a recess of a base unit on which the burner unit is mounted. The connecting part is designed to receive the burner unit. The mounting in the recess has the advantage that a simple mounting of the connecting part with the burner unit is made possible.

Preferably, the connecting part at least partially on an external thread, which can be screwed for mounting the burner unit with a nut. By means of the screw assembly with particularly simple means is possible.

Further advantages emerge from the following description of the drawing. In the drawing, an embodiment of the invention is shown. The drawings, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into meaningful further combinations.

Show it:

1 is a cooking appliance in perspective view Fig. 2 is a burner unit of the cooking appliance in a perspective view Fig. 3 shows the cooking appliance in a side sectional view

FIG. 4 shows the burner unit from FIG. 2 in a first lateral sectional view; FIG. 5 shows a top view of the burner unit from FIG. 2

6 shows the burner unit from FIG. 2 in a second lateral sectional view, FIG. 7 shows a bottom plate of the cooking appliance in a lateral sectional view

FIG. 1 shows a cooking appliance 1, which is designed to produce an open flame by burning a liquid fuel, in particular vegetable oil. It is designed for a power between 800 W to 1, 5 kW. The oil temperature to be reached should not exceed 650 ⁰ C. The cooking appliance 1 comprises a base unit 10, which serves as a receptacle of a windbreak 40. The base unit 10 has a plurality of ventilation openings 14 for improved ventilation. In addition, a tab 28 is provided on the base unit 10, on which a valve 29 is supported. The valve 29 serves to adjust the flow rate of the fuel amount. The wind shield 40 placed on the base unit 10 is a self-supporting tubular construction made of galvanized sheet metal. On the windshield 40 recordings 64, 65 can be seen, which are adapted to receive a pot carrier 52 against rotation. In the windbreak 40, a cleaning opening 47 is provided, which is closable by means of a cover plate 48. Through the cleaning opening 47 can be arranged inside the windshield 40 evaporator 4, in particular a nozzle provided in the evaporator for the evaporated fuel. The windshield 40 has in an upper and a lower region in each case radially encircling beads 42, 43 which serve to reinforce. The diameter of the windbreak is about 200 mm. Between the windshield 40 and the base unit 10, a gap 24 is formed, which serves to supply air from below to the flame. The gap width of the air gap is about 2.5 mm. The pot carrier 52 has support elements 54, 55, 56 which can be inserted in slot-shaped receivers 44, 45, 46 or in slot-shaped receivers 64, 64, 66. The receptacles 44, 45, 46 have a smaller overall depth relative to the receptacles 64, 65, 66, for which reason a pot placed on the pot carrier 52 is further away from the flame, and thus the heat transfer into the cooking product is lower. Due to the adjustability is also ensured that different cooking containers are used. The distance between a pot bottom (not shown) and the evaporator 4 is about 5 mm.

Figure 2 shows a burner unit 2 of the cooking appliance 1 with a receiving device 1 10 in perspective view. The receiving device 110 is made of sheet metal and comprises two individual preheating shells 112, 114, which are provided for receiving a second fuel for preheating the burner unit 2. In each of the Vorheizschalen 112, 114 at least 20 ml of a highly flammable liquid, such as alcohol or alcohol can be filled. The Vorheizschalen 112, 1 14 are formed and attached to a feed pipe 8, that in each case a preheating is arranged just below a portion of the evaporator 4, so that the heat generated by the combustion of the second fuel heat the respective portion of Evaporator 4 can heat up to a maximum. For attachment to the inlet pipe 8, a receptacle 9 is provided for this purpose, by means of which the receiving device 110 can be attached. The receptacle is formed by two horizontally extending parallel slots in the inlet pipe 8, which has the shape of a straight prism and assumes the function of a nut, by means of which the burner unit 2 with a connecting part (Fig. 3, Pos. 32) can be screwed. By attaching the receiving device 1 10 by means of the receptacle 9 is moreover ensured that the Vorheizschalen 112, 114 of the bottom plate (Fig. 3, Pos. 20) are decoupled. Particularly well, the shape of the evaporator 4 can be seen, which in one piece, consists of two identical tubular sections 5, 6, which are formed in the form of a double loop. The open ends of the double loop are connected together to the inlet pipe 8. Furthermore, a Flammleitelement 80 is shown, which surrounds the evaporator 4 in a central region of the tubular sections 5, 6 of the evaporator 4 and the air duct and the limitation of the flame is used. As a result, the evaporator 4 protrudes upwards and downwards in part beyond the flame guide element 80. The annular flame guide element 80 is made of stainless steel with a thickness of 1, 5 mm and has a height of 40 mm. The diameter of the flame guide 80 is 1 10 mm. It can be seen that the flame guide element 80 has, for cleaning purposes, a semicircular recess 87 at the lower edge 81 of the flame guide element 80, which serves as access to the nozzle. The flame guide member 80 is fixed to the evaporator 4 by means of a welded joint by welding the flame guide member 80 to the first tubular portion 5 at a first point and to the second tubular portion 6 at a second point opposite to the first. As a result, a tension between flame guide element 80 and evaporator 4 is prevented. In addition, holders 84, 85 can be seen on the flame guide element 80, on which a baffle plate 90 is held by means of tabs 96, 97. The baffle plate 90 serves for the formation and optimum mixing of the fuel-air mixture. The baffle plate 90 has a plurality of openings 92 arranged around a central area of the baffle plate 90. Thus, the central area of the baffle 90 remains free of openings. By means of the openings 92, a stowage effect of the fuel-air mixture is avoided. In addition, a recess 94 can be seen, which is located in a region of the baffle plate 90, which is closest to the evaporator 4. As a result, the closest evaporator section is optimally heated. FIG. 3 shows the cooking appliance 1 in a lateral sectional view. The base unit 10 is formed in two parts and comprises a perforated metal sheet 10 and a base plate 20 mounted thereon. The perforated metal sheet ring 10 has a plurality of ventilation openings 14. On the underside of the perforated sheet metal ring 12, a shielding plate 16 can be seen, which reduces the heat of radiation in the direction of the footprint. The bottom plate 20 has a trough-shaped recess 26 and serves as a catch basin for leakage. At the same time it reduces the heating of the footprint. On the bottom plate 20 spacers 22 can be seen, on soft the windshield (Fig. 1, Pos. 40) can be placed. The spacers 22 form a radially circumferential primary air gap, which serves to supply the air from below to the flame. Evident is a located in the middle of the bottom plate 20 recess 30, in which a connecting part 32 for connecting the burner unit 2 and a fuel line 36 is mounted. The connecting part 32 has below the bottom plate 20 in the form of a straight prism, which can be held for assembly purposes using a wrench. Evident is the fuel line 36, which is connected starting from the connecting part 32 to a valve 29. The valve 29 is mounted in a recess 18 which is located on a tab 28. In addition, a portion of a flexible fuel hose is shown leading to an external tank (not shown). Above the floor panel 20, the connecting part 32 has a circumferential external thread 33. The connecting part 32 is pushed from below through the recess 30 and screwed above the bottom plate 20 by means of a nut 34 on the external thread 33. Within the connecting part 32, a check valve 70 is formed, which prevents a return flow of hot oil in the direction of the flexible fuel hose. The check valve 70 comprises a closure element 72, which is designed as a ball. The ball of the check valve 70 is biased by its gravity in the closing direction. In addition, a filter 76 can be seen, which is designed as a sintered filter, which is connected downstream of the check valve. The filter 76 serves as a captive for the ball of the check valve 70. The filter 76 has sections an external thread 77, which is screwed into a corresponding internal thread 39 of a located in the connecting part 32 bore 38. In addition, the filter 76 is formed as a throttle device for increasing the flow resistance of the fuel. The connection of the first tubular evaporator section 5 to the inlet pipe 8 can also be recognized. FIG. 4 shows the burner unit 2 from FIG. 2 in a first lateral sectional view (section AA, FIG. 5). It can be seen a bottom of the baffle plate 90, which is mounted at a distance of 28 mm to an outlet opening of a nozzle 7. Particularly well, the recesses 94, 95 can be seen, which serve to heat the nearest evaporator section. The radius of curvature of the baffle plate 90 is 115 mm.

FIG. 5 shows a top view of the burner unit 2 from FIG. 2. The tabs 96, 97, 98 of the baffle plate 90, which are clipped into the holders 84, 85, 86 90 enclosed by the flame guide element 80, can be seen. Particularly well visible are the two individual preheat shells 1 12, 1 14 of the receiving device 1 10, which are each just below the recesses 94, 95 of the baffle plate 90. In this case, the edge of the baffle plate 90 formed by the recesses 94, 94 is parallel to the central longitudinal axis of the rectangular preheat shells 1 12, 1 14. Thus, the heat generated by the combustion of the second fuel is allowed to unhinder the areas of the evaporator 4, which are located between the flame guide element 80 and the baffle plate 90. In addition, a handle 1 16 is shown, by means of which the receiving device 110 can be held. The anti-jamming openings 92 of the baffle 90 are arranged such that a central area of the baffle 90 is free of openings.

FIG. 6 shows the burner unit from FIG. 2 in a second lateral sectional view (section B-B, FIG. 4). Evident is the inlet pipe 8, which has at a lower portion a bore with an internal thread, by means of which the burner unit 2 on the connecting part (Fig. 3, Pos. 32) can be mounted. Good to see is an inner region of the inlet pipe 8, from which the liquid fuel in the two tubular evaporator sections 5, 6 is transported.

FIG. 7 shows a bottom plate of the cooking appliance in a lateral sectional view. Evident are spacers 22, which serve to form the primary air gap. The check valve 70 formed in the connector 32 is shown. The connecting part 32 has an external thread 33 above the base plate 20 and a thread 39 formed inside the bore 38. By means of a nut 34, the connecting part 32 is screwed to the bottom plate 20. In addition, that serves External thread 33 for mounting the burner unit (Fig. 2, Pos. 2). The connecting part 32, the fuel line 36 and the valve 29 are integrally formed. The fuel line 36 is fixed to the connecting part 32 and the valve 29 by a welded connection. In a lower region, the connecting part 32 has a horizontally extending fuel channel of the same diameter, which represents the extension of the fuel line 36. Along a central longitudinal axis of the connecting part 32, the fuel channel bends upwards at right angles, for which reason it has a partial section which runs parallel to the central longitudinal axis of the connecting part 32. Above the fuel channel extending parallel to the central longitudinal axis, a region is formed whose diameter increases in the direction of flow of the fuel. This area essentially has a conical shape. Within this area is a ball formed as a closure element 72, which is biased by its gravity in the closing direction. As a captive for the closure member 72 is a sintered filter 76, which has a filter outer thread 77 and is screwed into the internal thread 39 of the connecting part 32.

reference numeral

1 cooking device 52 pot holder

2 burner unit 54,55,56 support element

4 Evaporator 58 Pot carrier top

5 first tubular section 59 pot carrier base

6 second tubular section 64, 65, 66 recording

7 nozzle 70 check valve

8 inlet pipe 72 closure element

9 receptacle 74 spring

10 base unit 76 filters

12 perforated sheet ring 77 Filter external thread

14 vents 78, 79 recess

16 shielding plate 80 flame guide

18 recess 81 lower edge

20 bottom plate 82 upper edge

22 spacers 84, 85, 86 bracket

24 air gap 87, 88 recess

26 recess 90 baffle plate

28 tab 92 openings

29 valve 94, 95 recess

30 recess 96, 97, 98 tab

32 connecting part 110 receiving device

33 external thread 112.1 14 pre-heating shell

34 Lock nut 116 Handle

36 fuel line 118 recess

38 hole D distance

39 female thread K spherical surface

40 Windbreak S Intersection

42, 43 bead

44, 45, 46 Recording

47 cleaning opening

48 cover plate

Claims

1. cooking appliance, in particular vegetable oil cooker, with a burner unit (2) for generating an open flame by combustion of a liquid fuel, and with a connecting part (32), which is disposed between the burner unit and a B rens fuel tank, characterized in that the Connecting part (32) comprises a check valve (70) which prevents a fuel flow from the burner unit (2) in the direction of the fuel tank.

2. Cooking appliance according to claim 1, characterized in that a closure element (72) of the check valve (70) is biased by its gravity in the closing direction.

3. Cooking appliance according to claim 2, characterized in that a spring (74) is provided, which biases the closure element (72) in the closing direction.

4. Cooking appliance according to claim 1 to 3, characterized in that a filter (76), in particular sintered filter, is provided.

5. Cooking appliance according to claim 4, characterized in that the filter (76) is connected downstream of the check valve (70).

6. Cooking appliance according to claim 4 or 5, characterized in that the filter (76) as a captive for the closure element (72) of the check valve (70) is formed.

7. Cooking appliance according to one of claims 4 to 6, characterized in that the filter (76) at least partially an external thread (77), which in a corresponding internal thread (39) has a bore (38) of a connecting part

(32) can be screwed.

8. Cooking appliance according to one of claims 4 to 7, characterized in that the filter (76) is designed as a throttle device for increasing the flow resistance of the fuel.

9. Cooking appliance according to one of claims 4 to 8, characterized in that the filter (76) has recesses (78,79) for applying a torque.

10. Cooking appliance according to one of the preceding claims, characterized in that the connecting part (32) is mounted in a recess (30) of a base unit (10) on which the burner unit (2) is mounted.

11. Cooking appliance according to claim 9, characterized in that the connecting part (32) at least partially an external thread (33), which for mounting the burner unit (2) with a nut (34) can be screwed.