CN116592399A - household ecological stove - Google Patents

Abstract

The application discloses a household ecological stove which adopts liquid ecological gas as fuel, the household ecological stove comprises an upper plate and a lower plate, a preheating cavity and a heating ring are arranged in the upper plate, the liquid ecological gas firstly flows into the preheating cavity, the heating ring heats the liquid ecological gas to enable the liquid ecological gas to be gasified into a gas state which can be ignited, the gas state is then conveyed into a burner for combustion, the lower plate is provided with the burner and an igniter, the upper plate and the lower plate are fixedly connected to form a finished stove, and the igniter and the burner pass through a through hole in the middle of the upper plate to face towards a cooker erected on the stove. The preheating cavity is arranged in the upper disc, so that the structure of the kitchen range is simplified, the whole kitchen range is more compact and reliable, meanwhile, the liquid fuel gas is heated by utilizing the heat generated by ignition of the fuel gas, the heat value of the fuel gas is fully utilized, and the energy is saved.

Description

household ecological stove

technical field

The invention relates to the technical field of stoves, in particular to a household ecological stove.

Background technique

Natural gas, coal gas, and liquefied petroleum gas are often used as fuels in existing household stoves. This type of gas needs to meet certain pressure requirements and temperature requirements during transportation and use, and there is a certain risk of explosion and deflagration. The invention patent with the application number CN201510066241.0 discloses a liquid ecological gas. The liquid ecological gas has no pressure and temperature requirements and can be used as a fuel to replace other fuels to a certain extent. However, it needs to be heated to vaporize it for easy ignition. Therefore, it is necessary to design a stove for the liquid ecological gas.

Contents of the invention

Therefore, in order to solve the above problems, the object of the present invention is to provide a household ecological stove, comprising a lower wall and a preheating chamber, the lower wall includes a bottom plate, the bottom plate is provided with an igniter, a thermocouple and a burner, and the preheating chamber includes an inlet and a preheating chamber. The outlet, the gas pipeline communicates with the inlet, and the outlet communicates with the burner.

Preferably, it also includes an upper plate, the upper plate includes a first outer edge plate arranged on the outer ring, the middle part of the upper plate is vertically penetrated to form a through hole, the preheating chamber is arranged inside the upper plate, and the preheating chamber The outlet and the inlet are symmetrically arranged on the first outer edge plate, and the end of the upper plate facing the lower plate is provided with a clamping groove, and a heating ring is arranged in the clamping groove;

The lower wall includes a second outer edge plate, the bottom plate and the second outer edge plate are connected by side plates, and the second outer edge plate is provided with a number of pipe holes to cooperate with the inlet/outlet of the preheating chamber;

The gas pipeline communicates with the inlet of the preheating chamber. After the gas flows through the preheating chamber, it flows out from the outlet of the preheating chamber and is introduced into the burner through the pipe. When the upper plate is connected to the lower plate, the igniter, thermocouple and combustion through the port.

Preferably, the burner includes a burner base, a burner middle cover and a burner upper cover, the middle part of the burner base is vertically penetrated to form a first gas hole for gas circulation; the burner middle cover includes an integrally formed gas The guide column and the connecting block, the middle part of the burner middle cover vertically penetrates to form a second gas hole for gas circulation, the gas guide column is clamped in the first gas hole, and the burner upper cover is clamped in the burner Cover, the side of the upper cover of the burner is provided with a third gas hole.

Preferably, there are two clamping grooves, both of which are ring-shaped and coaxially arranged on the upper plate, and the lower plate is provided with electrode grooves for the power cord of the heating coil to pass through.

Preferably, the lower plate is provided with two supporting columns, and the upper ends of the supporting columns abut against the heating ring.

Preferably, the first outer edge plate and the second outer edge plate are provided with matching bolt holes, and after the bolts pass through the bolt holes and are tightened, the upper plate and the lower plate are fixed.

Preferably, the middle circle of the upper plate extends upwards and protrudes relative to the igniter, the thermocouple and the burner to form an annular pan support.

Preferably, the preheating chamber includes an inlet and an outlet facing the lower wall, and the lower wall is provided with two pipe holes respectively matched with the inlet and the outlet.

Preferably, the preheating chamber communicates with the clamping groove, the heating ring is arranged at the connection between the preheating chamber and the clamping groove, and a sealing structure is provided at the connection between the preheating chamber and the clamping groove for sealing the preheating chamber .

In one of the solutions, it also includes a spiral tube, the spiral tube is arranged above the burner, the input port of the spiral tube is connected with the gas pipeline, the output port of the spiral tube is connected with the input port of the burner, and the The preheating chamber is arranged in the spiral tube.

A cooker panel using the household ecological cooker, comprising an outer frame, the outer frame is divided into a control part and a cooker part, the household ecological cooker is fixed at the cooker part, and a controller is arranged inside the control part, and the controller is electrically A solenoid valve is connected, and the solenoid valve is set on the gas pipeline to control the conduction of the gas pipeline. The heating coil, igniter, and thermocouple are all electrically connected to the controller. The upper end of the controller is connected with a knob, which protrudes relative to the outer frame.

Preferably, the end of the bottom plate facing away from the upper plate is provided with three fixing columns, the fixing columns are connected with screw rods, and the outer frame is provided with screw holes matching with the screw rods.

The beneficial effects of the present invention are:

(1) A preheating chamber is set in the upper plate, and the gas pipeline is connected to the preheating chamber. The liquid ecological gas flows in from the gas pipe, absorbs the heat from the heating ring in the preheating chamber, vaporizes, and then is transported to the burner by the pipeline , the preheating structure is combined in the cooker, saving space and the structure is simple and easy to realize;

(2) The preheating chamber is set on the upper plate, close to the burner, and can use part of the heat burned by the cooker to preheat the liquid ecological gas in the preheating chamber, make full use of the heat of the gas, and save electric energy and fuel energy;

(3) The upper plate and the lower plate are set separately, which is convenient for disassembly and maintenance. At the same time, the upper plate and the lower plate are closely matched, and the overall structure is compact and durable;

(4) Liquid ecological gas is used as fuel, only need to connect common liquid delivery pipes, the laying of pipes is simple, and can be integrated in a single cooker panel without occupying too much space.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the upper side structure schematic diagram of embodiment 1;

Fig. 2 is the schematic diagram of the explosion structure of embodiment 1;

Fig. 3 is the sectional structure schematic diagram of embodiment 1;

Fig. 4 is the structural representation of lower plate;

Fig. 5 is a schematic diagram of the upper side structure of the upper plate;

Fig. 6 is a schematic diagram of the lower side structure of the upper plate;

Fig. 7 is a schematic view of the structure of the upper side of the burner middle cover;

Fig. 8 is a schematic diagram of the underside structure of the burner middle cover;

Fig. 9 is a schematic structural view of the burner upper cover;

Fig. 10 is the structural representation of embodiment 2;

Figure 11 is a schematic diagram of the internal structure of Embodiment 2;

Fig. 12 is the structural representation of fixed post and screw rod;

Fig. 13 is the schematic cross-sectional structure diagram of embodiment 3;

Fig. 14 is the structural representation of embodiment 4;

Fig. 15 is a schematic cross-sectional structure diagram of embodiment 4;

Fig. 16 is the structural representation of embodiment 5;

Explanation of reference numerals: 1. upper plate; 11. first outer edge plate; 12. preheating chamber; 121. inlet; 122. outlet; 13. clamp groove; 14. heating ring; 15. port; ; 16, pipe structure block; 17, pot support portion; 2, lower plate; 21, second outer edge plate; 211, pipe hole; 22, bottom plate; 23, side plate; 24, burner; 241, burner base ; 2411, the first gas hole; 242, the middle cover of the burner; 2421, the second gas hole; 2422, the gas guide column; 2423, the connection block; 243, the burner upper cover; 2431, the third gas hole; 25, igniter; 26, thermocouple; 27, electrode groove; 28, support column; 29, fixed column; 291, screw rod; 3, screw hole; 4, gas pipeline; 5, gas pipeline; 6, outer frame; 61, control 62. Cooker department; 63. Controller; 64. Electromagnetic pulse valve; 65. Knob; 7. Spiral tube; 8. Preheating electric heating coil.

The realization of the purpose of the present invention, functional characteristics and advantages will be further described in conjunction with the embodiments and with reference to the accompanying drawings.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention.

In the description of this application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the application and simplification of the description, rather than indicating or implying that the referred device or element must have a specific orientation, use a specific orientation construction and operation, therefore should not be construed as limiting the application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and should not be construed as indicating or implying relative importance.

Unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be interpreted in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, It can also be an electrical connection; it can be a direct connection, or an indirect connection through an intermediary, or an internal communication between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application in specific situations.

Example 1:

Fig. 1-Fig. 9 shows the household eco-cooker provided by the present invention, comprises upper plate 1 and lower plate 2, and upper plate 1 and lower plate 2 are respectively provided with and is arranged on outer ring first outer edge board 11 and second outer edge plate 21 , the first outer edge plate 11 and the second outer edge plate 21 are provided with screw holes 3 for bolts to pass through, and the upper plate 1 and the lower plate 2 are fixed after the bolts are tightened;

There is a preheating chamber 12 inside the upper plate 1. The gas pipeline 4 communicates with the preheating chamber 12 and transports liquid ecological gas to the preheating chamber 12. The liquid ecological gas is preheated and vaporized in the preheating chamber 12 and then transported to the In the burner 24 of the lower plate 2, the heat source for preheating is specifically the heating ring 14. After the heating ring 14 is energized, heat is generated and diffused into the cooling cavity. The groove 13 is used to place the heating ring 14. The groove wall of the clamping groove 13 is close to the preheating chamber 12 so that the heating ring 14 can transfer heat to the preheating chamber 12. In this embodiment, the groove wall of the clamping groove 13 is the part of the preheating chamber 12. Cavity wall.

The lower plate 2 includes a bottom plate 22, the bottom plate 22 is connected to the second outer edge plate through the side plate 23, the upper end surface of the bottom plate 22 is provided with an igniter 25, a thermocouple 26 and a burner 24, and the second outer edge plate 21 corresponds to the preheating The inlet 121 and the outlet 122 of the chamber 12 are provided with pipe holes 211, the gas pipe 4 passes through the pipe holes 211 and then connects with the preheating chamber 12, the pipe holes 211 play the role of positioning and fixing, and the lower end of the bottom plate 22 is also provided with gaseous gas pipes. The gas pipeline 5 of the liquid ecological gas, one end of the gas pipeline 5 communicates with the outlet 122 of the preheating chamber 12 , and the other end is connected to the middle part of the lower end of the bottom plate 22 and communicates with the burner 24 .

Since the fuel used is liquid ecological gas, the gas pipeline 4 can be an ordinary water pipeline, such as a rubber hose for infusion, but the rubber hose has a low melting point, and the rubber hose close to the stove is easy to melt and cause leakage, so the end of the gas pipeline 4 is made of copper. Tubes are replaced, and copper pipes are also conveniently fixed to the inlet 121 of the preheating chamber 12, and the gas pipes 5 are all made of copper because they are located under the bottom plate 22. The copper mentioned here does not only refer to copper The simple substance mainly refers to the common copper pipes for water/gas transmission on the market, and it can also be other alloys or metals that meet the high temperature conditions of the stove.

The middle part of the upper plate 1 is vertically penetrated to form a port 15 for setting the igniter 25, the thermocouple 26 and the burner 24. The port 15 is circular in shape, and four arc-shaped notches 151 at equal angular intervals are arranged on the edge of the circle. , when the upper plate 1 and the lower plate 2 are connected and fixed, the burner 24 is located in the center of the through hole, the igniter 25, and the thermocouple 26 are respectively located at two adjacent gaps 151. The reason why four gaps 151 are set is because the upper The disc 1 is symmetrical as a whole and can be installed and used by rotating 180°. The outlet 122 and inlet 121 of the preheating chamber 12 have the same specifications and can be used interchangeably.

The burner 24 is composed of a burner base 241, a burner middle cover 242 and a burner upper cover 243, wherein the burner base 241 is integrally formed with the bottom plate 22, and the middle part of the burner base 241 vertically penetrates to form a first gas hole 2411. The middle cover 242 includes an integrally formed gas guide column 2422 and a connecting block 2423. The middle part of the burner middle cover 242 vertically penetrates to form a second gas hole 2421 for gas circulation, and the gas guide column 2422 is clamped in the first gas hole 2411. The upper end of the connection block 2423 is provided with a groove, which enables the upper cover to be clamped on the burner middle cover 242. The side of the burner upper cover 243 is provided with a third gas hole 2431, and the third gas hole 2431 is circumferentially distributed on the burner. The side of loam cake 243.

Two of the clamping grooves 13 are ring-shaped, and are coaxially arranged at the lower end of the upper plate 1. The cross section of the clamping grooves 13 is semicircular, and the heating ring 14 is clamped. Two through bottom plates 22, side The plate 23 and the electrode groove 27 of the second outer edge plate 21 are convenient for laying power lines and supplying power to the heating ring 14 .

The clip groove 13 is only fixed simply and is easy to loosen. In order to include the detachable and easy-to-maintain features of the heating ring 14, the heating ring 14 cannot be directly fixed in the clip groove 13, so that the heating ring 14 can be stably connected to the clip In the groove 13 , two supporting columns 28 are arranged on the upper end of the bottom plate 22 , and the upper ends of the supporting columns 28 can abut against the heating ring 14 to exert an upward supporting force on the heating ring 14 .

The upper plate 1 and the lower plate 2 are fixed together by bolts, the screw holes 3 are circumferentially distributed on the first outer edge plate 11 and the second outer edge plate 21, and the gas pipeline 4 should not be exposed on the upper surface of the cooktop. Both the outlet 122 and the inlet 121 of the heat chamber 12 are set downwards. In this embodiment, the outlet 122 and the inlet 121 of the preheating chamber 12 occupy the positions of two bolt holes, and the upper plate 1 extends upwards at these two positions. The protrusion forms a pipeline structure block 16, which is convenient for the installation of the gas pipeline 4 and reserves enough space for the liquid ecological gas to flow in/out of the preheating chamber 12.

Common cookers need to be used with metal pot supports. In this embodiment, the middle ring of the upper plate 1 extends upwards to form a ring-shaped pot support part 17. The pot support part 17 can replace the pot support in the prior art. The pot is supported above the burner 24, and because the pot support portion 17 is actually a part of the upward extension of the upper plate 1, the volume of the upper plate 1 is correspondingly increased, and the volume of the preheating chamber 12 inside the upper plate 1 can also be increased accordingly. The liquid ecological gas that can be accommodated is also more, and because the pot frame part 17 is in direct contact with the pot, part of the heat emitted by the high-temperature pot to the outside is transported to the preheating chamber 12 to be absorbed by the liquid ecological gas, further utilizing the liquid ecological gas The calorific value of combustion saves the electric energy consumed by the heating coil 14 in a disguised form.

The pot support part 17 is closely attached to the cooker, and if the air in the cooker is not circulated, it will affect the normal combustion. Therefore, a through hole or groove is provided on the side plate 23 to ensure the air circulation in the cooker. 17 carries out certain shape improvement, designs concave-convex structure on the pot support part 17, makes there is certain gap between the pot support part 17 and the pan to further improve the air circulation.

working principle:

The liquid ecological gas is transported from the gas pipeline 4 to the preheating chamber 12, the heating ring 14 provided at the lower end of the upper plate 1 emits heat after being energized, the liquid ecological gas absorbs the heat and vaporizes, and the gaseous liquid ecological gas flows out from the outlet 122 of the preheating chamber 12 Afterwards, it is transported into the burner 24, and then overflows from the third gas hole 2431 of the burner 24, while the igniter 25 is ignited to ignite the liquid ecological gas.

Example 2:

Figures 10-12 show a cooker panel provided by the present invention that includes the household ecological cooker described in Embodiment 1, including an outer frame 6, the outer frame 6 is divided into a control part 61 and a cooker part 62, and the household ecological cooker is fixed on the cooker At the part 62, the control part 61 is provided with a controller 63, the controller 63 is electrically connected with a solenoid valve, the solenoid valve is arranged on the gas pipeline 4 to control the conduction of the gas pipeline 4, the heating coil 14, the igniter 25, The thermocouples 26 are electrically connected to the controller 63 , the upper end of the controller 63 is connected with a knob 65 , and the knob 65 protrudes relative to the outer frame 6 .

The controller 63 controls the ignition of the igniter 25 in the cooker, the flameout protection of the thermocouple 26, and the start-up of the heating ring 14. The start-up of the heating ring 14 needs to cooperate with the conduction of the gas pipeline 4. The solenoid valve connected to the gas pipeline 4 is specifically: Electromagnetic pulse valve 64.

When the cooker is ignited, the knob 65 needs to be turned according to the operation steps, which is a prior art, and will not be repeated here.

In this embodiment, the end of the bottom plate 22 of the household ecological stove away from the upper plate 1 is provided with three fixed posts 29, the fixed posts 29 are connected with screw rods 291, and the outer frame 6 is provided with a screw rod 291 hole that cooperates with the screw rod 291. The nut is arranged on the part of the screw rod 291 protruding from the lower side of the outer frame 6 and tightened, so that the household ecological stove can be fixed on the cooker part 62 of the outer frame 6 .

Example 3:

Figure 13 shows the household ecological stove provided by the present invention. The difference between this embodiment and Embodiment 1 is that the preheating cavity 12 in this embodiment communicates with the clamping groove 13, and the heating ring 14 is fixedly installed in the clamping groove 13 and sealed. Block the connection between the preheating chamber 12 and the clamping groove 13. After the liquid ecological gas flows into the preheating chamber 12, it directly contacts with the heating ring 14. The heat absorption efficiency is higher and the vaporization is faster. Compared with the household ecological gas in Example 1 Stove, the household ecological stove of this embodiment has a faster start-up speed and can respond to the fire demand of the user in a timely manner, but there are also certain defects. The sealing of the heating ring 14 itself is not high, and the liquid ecological gas in the preheating chamber 12 is easy to To overflow from the clamp groove 13, it is usually necessary to add a sealing structure to block the gap between the clamp groove 13 and the preheating chamber 12, resulting in a fixed position of the heating ring 14, and subsequent disassembly and maintenance are difficult, so it needs to be selected according to actual needs.

Example 4:

Fig. 14 and Fig. 15 show the household eco-cooker provided by the present invention, comprise lower plate 2 and spiral tube 7, described lower plate 2 comprises base plate 22, is provided with igniter 25, thermocouple 26 and burner 24 on base plate 22, spiral The pipe 7 is arranged above the burner 24, the input port of the spiral pipe 7 is connected with the gas pipeline 4, the output port of the spiral pipe 7 is connected with the input port of the burner 24, a preheating chamber 12 is arranged in the spiral pipe 7, and the liquid ecological gas The gas pipeline 4 is input into the spiral tube 7, and the liquid ecological gas absorbs the flame heat emitted by the burner 24 below in the preheating chamber 12, heats up and vaporizes, and becomes a combustible gaseous state, and the gaseous liquid ecological gas is input through the pipeline The inside of the burner 24 is ignited again, and part of the flame heat generated by the burner 24 is used for preheating, and part of it is used for heating the pot erected on it, which reasonably and fully utilizes the combustion value of the liquid ecological gas and forms a heating cycle.

When the cooker is started, the burner 24 has no flame, and no heat can be provided to the liquid ecological gas. Therefore, a preheating electric heating coil 8 is added in the bottom plate 22 to provide heat to the liquid ecological gas in advance. After the preheating cycle can be achieved The preheating electric heating coil 8 stops heating, and the start-up time and power can be adjusted according to the actual situation. This part is prior art and will not be described in detail here.

Example 5:

Figure 16 shows the household ecological stove provided by this embodiment. The difference between this embodiment and Embodiment 4 is that there are three burners arranged in a triangle. Correspondingly, the spiral tube is coiled above the three burners to form a circular Triangular shaped coil with curved corners. Compared with Embodiment 4, in this embodiment, two burners are added, the firepower of the stove is larger, and the pot can be heated faster.

The above descriptions are only optional embodiments of the present invention, and do not limit the patent scope of the present invention. Under the inventive concept of the present invention, the equivalent structural transformation made by using the description of the present invention and the contents of the accompanying drawings, or direct/indirect Application in other related technical fields is included in the patent protection scope of the present invention.

Claims (10)

1. Household ecological stove, it is characterized in that, comprises lower plate (2) and preheating cavity (12), and described lower plate (2) comprises base plate (22), and base plate (22) is provided with igniter (25), thermoelectric Couple (26) and burner (24), preheating cavity (12) comprises inlet (121) and outlet (122), gas pipeline (4) is communicated with inlet (121), and described outlet (122) is connected with burner ( 24) Connected. 2. The household ecological stove according to claim 2, characterized in that, it also includes an upper plate (1), and the upper plate (1) includes a first outer edge plate (11) arranged on the outer ring, and the upper plate (1) The middle part is vertically penetrated to form a port (15), the preheating chamber (12) is arranged inside the upper plate (1), and the outlet (122) and inlet (121) of the preheating chamber (12) are symmetrical It is arranged on the first outer edge plate (11), and the end of the upper plate (1) facing the lower plate (2) is provided with a clamping groove (13), and a heating ring (14) is arranged in the clamping groove (13); The lower wall (2) includes a second outer edge plate (21), the bottom plate (22) and the second outer edge plate (21) are connected through side plates (23), and the second outer edge plate (21) A plurality of pipe holes (211) are arranged on the top to cooperate with the outlet (122) or inlet (121) of the preheating chamber (12); When the upper plate (1) is connected with the lower plate (2), the igniter (25), thermocouple (26) and burner (24) pass through the port (15). 3. household ecological stove according to claim 2, is characterized in that, described burner (24) comprises burner base (241), burner middle cover (242) and burner loam cake (243), described The middle part of the burner base (241) vertically penetrates to form a first gas hole (2411) for gas circulation; The middle part of the burner middle cover (242) is vertically penetrated to form a second gas hole (2421) for gas circulation, and the gas guide column (2422) is clamped in the first gas hole (2411), and the burner upper cover (243) Clipped on the burner middle cover (242), the side of the burner upper cover (243) is provided with a third gas hole (2431). 4. The household ecological stove according to claim 2, characterized in that, there are two clamping grooves (13) and they are all ring-shaped and coaxially arranged on the upper plate (1), and the lower plate (2) An electrode slot (27) is provided for the power line of the heating coil (14) to pass through. 5 . The household ecological stove according to claim 2 , characterized in that, two support columns ( 28 ) are arranged on the lower wall ( 2 ), and the upper ends of the support columns ( 28 ) abut against the heating ring ( 14 ). 6. The household ecological stove according to claim 2, characterized in that, the first outer edge plate (11) and the second outer edge plate (21) are provided with matching bolt holes, and the bolts pass through the bolt holes and After tightening, the upper plate (1) and the lower plate (2) are fixed. 7. The household ecological stove according to claim 2, characterized in that, the middle circle of the upper plate (1) extends upwards and protrudes relative to the igniter (25), thermocouple (26) and burner (24) Ring-shaped pot support part (17). 8. The household ecological stove according to claim 2, characterized in that, the preheating chamber (12) comprises an inlet (121) and an outlet (122) arranged towards the lower wall (2), the lower wall (2) Two pipe holes (211) are provided to cooperate with the inlet (121) and the outlet (122) respectively. 9. The household ecological stove according to claim 2, characterized in that, the preheating cavity (12) communicates with the clamping groove (13), and the heating ring (14) is arranged between the preheating cavity (12) and the clamping groove (13). The connection between the groove (13) and the connection between the preheating chamber (12) and the clamping groove (13) is also provided with a sealing structure for sealing the preheating chamber (12). 10. Household ecological stove according to claim 1, is characterized in that, also comprises spiral pipe (7), and described spiral pipe (7) is arranged on the top of described burner (24), and the spiral pipe (7) The input port is connected to the gas pipeline (4), the output port of the spiral pipe (7) is connected to the input port of the burner (24), and the preheating chamber (12) is arranged in the spiral pipe (7).