Natural gas far infrared drying box for papermaking

Abstract

The utility model provides a natural gas far infrared drying box for papermaking, which relates to the technical field of drying and comprises a rack, a drying box body is arranged at the upper end of the rack, a conveying belt is arranged between the drying box body and the rack and penetrates through two sides of the drying box body, a heating module is arranged on one side of the rack, and a heating module is arranged on the other side of the rack. An infrared heating component is arranged in the drying box body, and hot air generated by the heating module enters the infrared heating component along the air conveying pipe. According to the utility model, the quartz tube is used for direct radiation heating, the heat efficiency is 30-50% higher than that of the traditional hot air drying, preheating air is not needed, the temperature of materials is quickly raised, the drying time can be shortened by more than 50%, and the materials are prevented from being polluted due to non-contact heating.

Description

Technical Field

[0001] This utility model relates to the field of drying technology, and in particular to a natural gas far-infrared drying box for papermaking. Background Technology

[0002] Drying is an indispensable and crucial step in the papermaking process. Its core purpose is to remove moisture from the paper, thereby giving it the physical properties, appearance quality, and stability required for use.

[0003] In the prior art, when drying paper, hot air is often blown onto the paper surface to quickly dehydrate the paper surface. The inventor found that blowing hot air directly onto the paper can easily cause the paper surface to heat up quickly, thereby quickly dehydrating the paper surface. However, hot air drying requires preheating the air inside the drying oven in advance. At the same time, the hot air acts directly on the paper surface, and impurities (dust) in the air will be blown onto the paper surface, thus requiring a high level of air cleanliness. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a natural gas far-infrared drying oven for papermaking.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a natural gas far-infrared drying box for papermaking, comprising a frame, a drying chamber being provided at the upper end of the frame, a conveyor belt being provided between the drying chamber and the frame, wherein the conveyor belt passes through both sides of the drying chamber, a heating module being provided on one side of the frame, and an infrared heating component being provided inside the drying chamber, wherein the heating module generates hot air that enters the infrared heating component along a gas supply pipe, the hot air generates far-infrared rays by heating the heating tube in the infrared heating component, and the far-infrared rays irradiate the paper on the conveyor belt for drying, wherein the heating tube is a quartz tube heater.

[0006] The effect achieved by the above components is as follows: the paper to be dried is laid flat on the conveyor belt, and the heating module is activated. The heating module generates heat and uses a fan to blow the heat into the heating tube. The quartz tube heater is a tubular quartz tube. After absorbing the heat from the hot air, the quartz tube itself will also emit far-infrared rays in the form of thermal radiation. Because the surface temperature of a quartz tube is lower than that of hot air (usually 100-200°C lower), its radiation peak wavelength is longer and more biased towards the far-infrared region. The exterior or interior of the quartz tube can be coated with a far-infrared radiation coating (the coating can be iron oxide (Fe2O3), chromium oxide (Cr2O3), nickel oxide (NiO), etc., with an emissivity of over 0.9 in the far-infrared band, while the emissivity of an uncoated quartz tube is about 0.8; it can also be silicon carbide (SiC) or silicon nitride (Si3N4), which can adjust the radiation peak wavelength to a high-efficiency drying range of 5-15 micrometers). The far-infrared radiation coating reduces visible light and near-infrared radiation (reducing ineffective heat dissipation), concentrating more energy in the far-infrared band for direct radiative heating. The thermal efficiency is 30%-50% higher than that of traditional hot air drying. There is no need to preheat the air, the material heats up rapidly, and the drying time can be shortened by more than 50%. Non-contact heating avoids material contamination.

[0007] Preferably, the infrared heating component includes a first mounting base and a second mounting base, wherein a plurality of heating tubes are evenly installed between the first mounting base and the second mounting base, and hot air in the heating tubes enters from the first mounting base, passes through the heating tubes, and exits from the second mounting base.

[0008] The above components achieve the following effect: the heating element can be detachably installed on the surface of the first mounting base and the second mounting base, and the heating element can be replaced (repaired).

[0009] Preferably, the two ends of the heating tube are slidably inserted into the first mounting base and the second mounting base, respectively. The first mounting base and the second mounting base are provided with cavities inside. One end of the heating tube abuts against the inner part of the second mounting base. An elastic member is provided between the first mounting base and the heating tube. The elastic member abuts against the other end of the heating tube to fix the heating tube.

[0010] The aforementioned components achieve the following effects: When the heating tube needs to be disassembled, push the heating tube towards the first mounting base, thereby causing the heating tube to squeeze the elastic member, thus pulling one end of the heating tube out of the second mounting base, and then pulling the heating tube out. The connection between the heating tube and the first mounting base is a high-temperature resistant flexible layer (which can be an expanded graphite layer, or the heating tube can be inserted into the first mounting base with the help of an aluminum foil tube). When the heating tube needs to be installed, first insert one end of the heating tube into the first mounting base, then squeeze the elastic member, and then insert the other end of the heating tube into the second mounting base. Release the heating tube so that it is pushed into the second mounting base under the action of the elastic member, thereby allowing hot air to enter the first mounting base along the gas supply pipe. The hot air inside the first mounting base enters the heating tube along the vent hole, then enters the second mounting base through the vent hole on the surface of the heating tube, and finally exits from the gas supply pipe on the second mounting base (allowing for later waste heat reuse).

[0011] Preferably, the elastic component includes a guide rod, which is fixed in the inner cavity of the first mounting base. A sealing plate is slidably connected to the surface of the guide rod, and the sealing plate abuts against the port of the heating tube. A spring is sleeved on the surface of the guide rod, wherein the two ends of the spring are fixed to the sealing plate and the inner cavity of the first mounting base, respectively. An air vent is opened on the surface of the heating tube relative to the surfaces of the inner cavities of the first and second mounting bases.

[0012] The effect achieved by the above components is as follows: when the heating tube is inserted into the first mounting base, it presses against the surface of the sealing plate, the sealing plate blocks the port of the heating tube, and the heating tube is pushed to compress the spring by the sealing plate, thereby allowing the heating tube to enter the first mounting base.

[0013] Preferably, a second sealing ring is fitted on the surface of the heating tube, the second sealing ring is fixed to the surface of the first mounting base, a first sealing ring is fitted on the surface of the heating tube, the first sealing ring is fixed to the surface of the second mounting base, and thermally conductive silicone grease is filled between the first sealing ring and the heating tube, and between the second sealing ring and the heating tube.

[0014] The effect achieved by the above components is that the first sealing ring and the second sealing ring can be flexible graphite, and thermally conductive silicone grease is used for further sealing.

[0015] Preferably, the frame is provided with a conveying module, which drives the conveyor belt to rotate. The conveying module includes a motor, wherein the output end of the motor is equipped with a pulley, the conveyor belt is fitted on the belt roller to convey paper, the rotating belt roller end is equipped with a pulley, and the two pulleys are driven by a belt.

[0016] Preferably, the heating module includes a heating box, inside which is a combustion chamber. An isolation chamber separates the heating box from the combustion chamber. A controller and a temperature sensor are located inside the isolation chamber. A gas pipe and an air pipe are connected to the side of the heating box. The gas pipe is connected to a natural gas pipeline via a proportional control valve and a gas flow meter. The air pipe is connected to an air compressor via a proportional control valve. A burner is located inside the combustion chamber, igniting the mixture of natural gas and air. The hot combustion gas enters the heating pipe through a gas supply pipe (first passing through a filter to remove large particles of soot). A copper pipe is located inside the combustion chamber, with two sets of heat exchange fins on its surface. A circulating pump supplies water to the copper pipe for circulation, allowing the circulating hot water to transfer heat... In this system, water is input from near the gas pipeline. A set of heat exchange fins on the surface of the copper pipe near the gas pipeline absorbs heat from the gas far from the combustion area for preheating. Another set of heat exchange fins near the heat dissipation area quickly absorbs the combustion temperature for heat utilization (the combination of copper pipe and heat exchange fins can, to some extent, prevent the natural gas combustion temperature from becoming too high). The hot water circulating in the copper pipe can be reused for heat. A temperature sensor monitors the internal temperature of the combustion chamber and transmits the temperature signal to the controller. The controller controls two proportional regulating valves (i.e., controls the input of gas and air, thereby controlling the degree of combustion and regulating the combustion temperature). When the temperature is too high, an alarm is triggered. When there is a gas leak, the gas leak sensor transmits the signal to the PLC controller, which then controls the leak signal to trigger an alarm.

[0017] Compared with the prior art, the advantages and positive effects of this utility model are as follows:

[0018] In this invention, the heating module generates heat, which is then blown into the heating tube by a fan. After absorbing the heat from the hot air, the quartz tube also emits far-infrared rays in the form of thermal radiation. The quartz tube has a longer peak wavelength and is more biased towards the far-infrared region, which can concentrate more energy in the far-infrared band for direct radiative heating. The thermal efficiency is 30% to 50% higher than that of traditional hot air drying. There is no need to preheat the air, the material heats up quickly, and the drying time can be shortened by more than 50%. Non-contact heating avoids material contamination. Attached Figure Description

[0019] Figure 1 A three-dimensional structural schematic diagram of a far-infrared drying oven for papermaking using natural gas is provided for this utility model.

[0020] Figure 2 This is a schematic diagram of the internal structure of the drying oven body of this utility model;

[0021] Figure 3 This is an internal schematic diagram of the second mounting base of this utility model;

[0022] Figure 4This utility model Figure 3 Enlarged view of point B;

[0023] Figure 5 This utility model Figure 3 Enlarged view of point A;

[0024] Figure 6 This is a schematic diagram of the internal structure of the heating box of this utility model;

[0025] Figure 7 This is the control flowchart of this utility model;

[0026] Figure 8 This is the control flowchart of the feedback module of this utility model.

[0027] Legend: 1. Frame; 2. Conveying module; 3. Conveying belt; 4. Drying chamber; 5. Heating module; 51. Heating box; 52. Isolation chamber; 53. Copper pipe; 54. Heat exchange fins; 55. Gas pipe; 56. Air pipe; 6. Gas supply pipe; 7. Infrared heating component; 71. Heating tube; 72. First mounting base; 73. Second mounting base; 74. First sealing ring; 75. Guide rod; 76. Spring; 77. Sealing plate; 78. Second sealing ring. Detailed Implementation

[0028] Example 1, such as Figure 1-8As shown, a far-infrared drying box for papermaking using natural gas includes a frame 1, a drying chamber 4 at the upper end of the frame 1, and a conveyor belt 3 between the drying chamber 4 and the frame 1. The conveyor belt 3 passes through both sides of the drying chamber 4. A heating module 5 is provided on one side of the frame 1, and an infrared heating component 7 is provided inside the drying chamber 4. The heating module 5 generates hot air that enters the infrared heating component 7 along the gas supply pipe 6. The hot air generates far-infrared rays by heating the heating tube 71 in the infrared heating component 7. The far-infrared rays irradiate the paper on the conveyor belt 3 to dry it. The heating tube 71 is a quartz tube heater. The paper to be dried is laid flat on the conveyor belt 3. By activating the heating module 5, the heating module 5 generates heat, which is blown into the heating tube 71 by a fan. The quartz tube heater is a tubular quartz tube. After absorbing the heat from the hot air, the quartz tube itself also emits far-infrared rays in the form of thermal radiation. Because the surface temperature of a quartz tube is lower than that of hot air (typically 100-200°C lower), its radiation peak wavelength is longer and more biased towards the far-infrared region. A far-infrared radiation coating can be sprayed onto the exterior or interior of the quartz tube (the coating can be made of iron oxide, chromium oxide, nickel oxide, etc., with an emissivity of over 0.9 in the far-infrared band, compared to approximately 0.8 for uncoated quartz tubes; it can also be made of silicon carbide or silicon nitride, which can adjust the radiation peak wavelength to the efficient drying range of 5-15 micrometers). This far-infrared radiation coating reduces visible and near-infrared radiation (reducing ineffective heat dissipation) and concentrates more energy in the far-infrared band for direct radiative heating. The thermal efficiency is 30% to 50% higher than that of traditional hot air drying. No preheating of air is required, the material heats up rapidly, and the drying time can be shortened by more than 50%. Non-contact heating avoids material contamination. The infrared heating component 7 includes a first mounting base 72 and a second mounting base 73, wherein multiple heating tubes 71 are evenly installed between the first mounting base 72 and the second mounting base 73. Hot air in the heating tubes 71 enters from the first mounting base 72, passes through the heating tubes 71, and is discharged from the second mounting base 73. The heating tubes 71 are detachably installed on the surfaces of the first mounting base 72 and the second mounting base 73, and the heating tubes 71 can be replaced (repaired).

[0029] like Figure 1-8As shown, the two ends of the heating tube 71 are slidably inserted into the first mounting base 72 and the second mounting base 73, respectively. The first mounting base 72 and the second mounting base 73 have cavities inside. One end of the heating tube 71 abuts against the inner part of the second mounting base 73. A spring member is provided between the first mounting base 72 and the heating tube 71, and the spring member abuts against the other end of the heating tube 71 to fix the heating tube 71. When it is necessary to remove the heating tube 71, the heating tube 71 is pushed towards the first mounting base 72, thereby causing the heating tube 71 to squeeze the spring member, thus pulling one end of the heating tube 71 out of the second mounting base 73, and then pulling the heating tube 71 out. The heat pipe 71 has a high-temperature resistant flexible layer (which can be an expanded graphite layer or the heat pipe 71 can be inserted into the first mounting base 72 using an aluminum foil tube) at the connection point between the heat pipe 71 and the first mounting base 72. When the heat pipe 71 needs to be installed, first insert one end of the heat pipe 71 into the first mounting base 72, then squeeze the elastic member, and then insert the other end of the heat pipe 71 into the second mounting base 73. Release the heat pipe 71 so that it pushes against the second mounting base 73 under the action of the elastic member, thereby allowing hot air to enter the first mounting base 72 along the gas supply pipe 6. The hot air inside the first mounting base 72 enters the heat pipe 71 along the vent hole, and then exits from the heat pipe 71... The surface vent leads to the second mounting base 73, and finally the air is discharged from the air supply pipe 6 on the second mounting base 73 (for later waste heat reuse). The elastic component includes a guide rod 75, which is fixed in the inner cavity of the first mounting base 72. A sealing plate 77 is slidably connected to the surface of the guide rod 75, and the sealing plate 77 abuts against the end of the heating tube 71. A spring 76 is sleeved on the surface of the guide rod 75, and the two ends of the spring 76 are fixed to the sealing plate 77 and the inner cavity of the first mounting base 72, respectively. The surface of the heating tube 71 has vent holes relative to the surfaces of the inner cavities of the first mounting base 72 and the second mounting base 73. When the heating tube 71 is inserted into the first mounting base 72, it abuts against the sealing plate. On the surface of 77, the sealing plate 77 blocks the port of the heating tube 71. The heating tube 71 is pushed to compress the spring 76, thereby allowing the heating tube 71 to enter the first mounting base 72. The surface of the heating tube 71 is fitted with a second sealing ring 78, which is fixed to the surface of the first mounting base 72. The surface of the heating tube 71 is fitted with a first sealing ring 74, which is fixed to the surface of the second mounting base 73. Thermally conductive silicone grease is filled between the first sealing ring 74 and the heating tube 71, and between the second sealing ring 78 and the heating tube 71. The first sealing ring 74 and the second sealing ring 78 can be flexible graphite, and thermally conductive silicone grease is used for further sealing.

[0030] like Figure 1-8As shown, a conveying module 2 is installed on the frame 1. The conveying module 2 drives the conveyor belt 3 to rotate. The conveying module 2 includes a motor, and the output end of the motor is equipped with a pulley. The conveyor belt 3 is fitted on a roller to convey paper. The rotating roller end is equipped with a pulley. The two pulleys are driven by a belt. The heating module 5 includes a heating box 51, which contains a combustion chamber. An isolation chamber 52 is also installed inside the heating box 51, separating the heating box 51 from the combustion chamber. A controller and a temperature sensor are installed inside the isolation chamber 52. A gas pipe 55 and an air pipe 56 are connected to the side of the heating box 51. The gas pipe 55 is connected to a natural gas pipeline through a proportional regulating valve and a gas flow meter. The air pipe 56 is connected to an air compressor through a proportional regulating valve. A burner is installed inside the combustion chamber. The burner ignites the mixture of natural gas and air. The combustion hot gas enters the heating pipe 71 through the gas supply pipe 6 (where it first passes through a filter to filter out large particles of soot inside the hot gas). The unit is equipped with a copper pipe 53, and two sets of heat exchange fins 54 are provided on the surface of the copper pipe 53. Water is fed into the copper pipe 53 for circulation using a circulating pump. The circulating hot water can utilize heat. The water is input from a position near the gas supply pipe 6. The set of heat exchange fins 54 on the surface of the copper pipe 53 near the gas supply pipe 6 can first absorb the hot air away from the combustion part for preheating, and the set of heat exchange fins 54 near the heat dissipation part can quickly absorb the combustion temperature for heat utilization (the cooperation of the copper pipe 53 and the heat exchange fins 54 can, to a certain extent, prevent the natural gas combustion temperature from being too high). The hot water circulating in the copper pipe 53 can be reused for heat. The temperature sensor monitors the internal temperature of the combustion chamber and transmits the temperature signal to the controller. The controller controls two proportional regulating valves (i.e., controls the input of gas and air, thereby controlling the degree of combustion and regulating the combustion temperature). When the temperature is too high, an alarm is issued. When there is a gas leak, the gas leak sensor transmits the signal to the PLC controller, and then the PLC controls the leak signal to issue an alarm through the alarm device.

[0031] The working principle is as follows: The paper to be dried is laid flat on the conveyor belt 3. The heating module 5 is activated, generating heat which is then blown into the heating tube 71 by a fan. The quartz tube heater is a tubular quartz tube that, after absorbing heat from the gas, also emits far-infrared rays in the form of thermal radiation. The gas pipe 55 is connected to the natural gas pipeline via a proportional regulating valve and a gas flow meter. The air pipe 56 is connected to the air compressor via the proportional regulating valve. A burner is installed inside the combustion chamber, igniting the mixture of natural gas and air. The combustion heat enters the heating tube 71 through the gas supply pipe 6 (after passing through a filter to remove large particles of soot). A copper tube 53 is installed inside the combustion chamber, with two sets of heat exchange fins 54 on its surface. A circulating pump inputs water into the copper tube 53 for circulation. The circulating hot water utilizes the heat. The water is input from near the gas supply pipe 6, near the set of heat exchange fins 54 on the surface of the copper tube 53. 4. The system can preheat by absorbing hot air away from the combustion chamber. A set of heat exchange fins 54 near the heat dissipation area can quickly absorb the combustion temperature for heat utilization (the cooperation of copper pipe 53 and heat exchange fins 54 can, to some extent, prevent the natural gas combustion temperature from becoming too high). The hot water circulating in the copper pipe 53 can be reused for heat. The temperature sensor monitors the internal temperature of the combustion chamber and transmits the temperature signal to the controller. The controller controls two proportional regulating valves (i.e., controls the input of gas and air, thereby controlling the degree of combustion and regulating the combustion temperature). An alarm is triggered when the temperature is too high. When there is a gas leak, the gas leak sensor transmits a signal to the PLC controller, which then... The control system sends a leak signal to the alarm. When the heating tube 71 is inserted into the first mounting base 72, it presses against the surface of the sealing plate 77, which blocks the port of the heating tube 71. Continuing to push the heating tube 71 causes the sealing plate 77 to compress the spring 76, thus allowing the heating tube 71 to enter the first mounting base 72. When it is necessary to remove the heating tube 71, push it towards the first mounting base 72, causing it to compress the elastic member, thereby pulling one end of the heating tube 71 out of the second mounting base 73. Then, pull the heating tube 71 out. The connection between the heating tube 71 and the first mounting base 72 is a high-temperature resistant flexible layer (which can be expandable). The graphite layer can also be a heating tube 71 inserted into the first mounting base 72 via an aluminum foil tube. When the heating tube 71 needs to be installed, first insert one end of the heating tube 71 into the first mounting base 72, then squeeze the elastic member, and then insert the other end of the heating tube 71 into the second mounting base 73. Release the heating tube 71 so that it pushes against the second mounting base 73 under the action of the elastic member, so that the hot air enters the first mounting base 72 along the gas supply pipe 6. The hot air inside the first mounting base 72 enters the heating tube 71 along the vent hole, and then enters the second mounting base 73 from the vent hole on the surface of the heating tube 71. Finally, it is discharged from the gas supply pipe 6 on the second mounting base 73 (which can be used for later waste heat reuse).

[0032] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model in any other way. Any person skilled in the art may use the disclosed technical content to make changes or modifications to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this utility model, without departing from the scope of the utility model's technical solution, still fall within the protection scope of this utility model's technical solution. In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood through specific circumstances.

Claims

1. A far-infrared drying oven for papermaking using natural gas, characterized in that: The device includes a frame (1), with a drying chamber (4) at the top of the frame (1). A conveyor belt (3) is provided between the drying chamber (4) and the frame (1), with the conveyor belt (3) passing through both sides of the drying chamber (4). A heating module (5) is provided on one side of the frame (1), and an infrared heating component (7) is provided inside the drying chamber (4). The heating module (5) generates hot air that enters the infrared heating component (7) along the air supply pipe (6). The hot air generates far-infrared rays by heating the heating tube (71) in the infrared heating component (7), and the far-infrared rays irradiate the paper on the conveyor belt (3) for drying.

2. The far-infrared drying oven for papermaking using natural gas according to claim 1, characterized in that: The infrared heating component (7) includes a first mounting base (72) and a second mounting base (73), wherein a plurality of heating tubes (71) are evenly installed between the first mounting base (72) and the second mounting base (73), and the hot air in the heating tubes (71) enters from the first mounting base (72), passes through the heating tubes (71), and exits from the second mounting base (73).

3. The far-infrared drying oven for papermaking using natural gas according to claim 2, characterized in that: The two ends of the heating tube (71) are slidably inserted into the first mounting base (72) and the second mounting base (73) respectively. The first mounting base (72) and the second mounting base (73) are provided with cavities. One end of the heating tube (71) abuts against the inner part of the second mounting base (73). An elastic member is provided between the first mounting base (72) and the heating tube (71). The elastic member abuts against the other end of the heating tube (71) to fix the heating tube (71).

4. The far-infrared drying oven for papermaking using natural gas according to claim 3, characterized in that: The elastic component includes a guide rod (75), which is fixed in the inner cavity of the first mounting base (72). A sealing plate (77) is slidably connected to the surface of the guide rod (75). The sealing plate (77) abuts against the port of the heating tube (71). A spring (76) is sleeved on the surface of the guide rod (75). The two ends of the spring (76) are fixed to the sealing plate (77) and the inner cavity of the first mounting base (72), respectively. An air vent is opened on the surface of the heating tube (71) relative to the surfaces of the inner cavities of the first mounting base (72) and the second mounting base (73).

5. The far-infrared drying oven for papermaking using natural gas according to any one of claims 2-4, characterized in that: The surface of the heating tube (71) is fitted with a second sealing ring (78), which is fixed to the surface of the first mounting base (72). The surface of the heating tube (71) is fitted with a first sealing ring (74), which is fixed to the surface of the second mounting base (73). Thermally conductive silicone grease is filled between the first sealing ring (74) and the heating tube (71), as well as between the second sealing ring (78) and the heating tube (71).

6. The far-infrared drying oven for papermaking using natural gas according to claim 1, characterized in that: The heating tube (71) is a quartz tube heater.

7. The far-infrared drying oven for papermaking using natural gas according to claim 1, characterized in that: The frame (1) is provided with a conveying module (2), which drives the conveyor belt (3) to rotate. The conveying module (2) includes a motor, wherein the output end of the motor is equipped with a pulley, the conveyor belt (3) is fitted on the belt roller to convey paper, the rotating belt roller end is equipped with a pulley, and the two pulleys are driven by a belt.

8. The far-infrared drying oven for papermaking using natural gas according to claim 1, characterized in that: The heating module (5) includes a heating box (51), wherein a combustion chamber is provided inside the heating box (51), and the gas is burned inside the combustion chamber to generate hot gas, which enters the heating tube (71) through the gas supply pipe (6).

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