Novel compressed gas heating device

Abstract

The utility model discloses a novel compressed gas heating device, relates to the field of gas heating devices, and can solve the problem that in the prior art, a gas heating device in the current market is difficult to be matched with most secondary cleaning machines for use. In addition, a copper pipe temperature controller and an air outlet temperature controller cannot be independently detached and placed outside the secondary cleaning machine, so that whether the temperature controllers generate an alarm due to excessive heating or not cannot be visually judged, and meanwhile, temperature adjustment cannot be performed outside. An air inlet pipe and an air outlet pipe in the copper pipe part are both connected with the secondary cleaning machine in a threaded connection mode, in addition, a first temperature controller and a second temperature controller are fixed to the end face of the heating cabinet in a threaded connection mode, and high-precision sensors are arranged in the first temperature controller and the second temperature controller and used for detecting temperature data in real time, so that the working efficiency is improved, and the cost is reduced. And the risk of equipment damage possibly caused by too high or too low temperature is reduced.

Description

Technical Field

[0001] The utility model relates to the field of gas heating devices, in particular to a novel compressed gas heating device. Background Art

[0002] As an indispensable and key component of railway freight cars, the brake device's maintenance work is aimed at ensuring that the performance of the brake device can be restored and maintained in a stable state. Among them, the 120-type control valve is the core component of the brake device. After long-term use, its performance may be affected to a certain extent, so it needs to be regularly maintained. During the maintenance of the 120-type control valve, after the sliding valve seat is finely ground, in order to ensure that the internal cleanliness of the valve body meets the standard requirements, the main valve body needs to be placed in a secondary cleaning machine for deep cleaning. During the cleaning process, pollutants such as oil, impurities and copper powder in the inner cavity of the valve body can be effectively removed to ensure that the inside of the valve body is clean and free of residue. After the cleaning process is completed, the valve body needs to be air-dried to prevent residual moisture from corroding the valve body or affecting the normal operation of the brake device. The entire maintenance process must follow strict operating procedures and quality standards to ensure that the 120-type control valve can restore its original performance after maintenance, providing a strong guarantee for the safe operation of railway freight cars.

[0003] However, air drying at room temperature is not effective. The gas heating devices currently on the market have many inconveniences in use, especially they are difficult to use with most secondary cleaning machines. In addition, the copper tube thermostat and the air outlet thermostat cannot be removed separately and placed outside the secondary cleaning machine, making it impossible to intuitively determine whether the thermostat has generated an alarm due to overheating, and it is also impossible to adjust the temperature externally, which makes the overall use process lack sufficient stability and reliability. Utility Model Content

[0004] In order to solve the problem that the gas heating devices currently on the market are difficult to be used in conjunction with most secondary cleaning machines in the prior art, and the copper tube thermostat and the air outlet thermostat cannot be removed separately and placed outside the secondary cleaning machine, resulting in the inability to intuitively determine whether the thermostat generates an alarm due to overheating, and the temperature cannot be adjusted externally, the present application provides a new compressed gas heating device to solve the above problem.

[0005] In order to achieve the above purpose, the technical solution adopted in this application is:

[0006] A novel compressed gas heating device includes a secondary cleaning machine, a heating cabinet, a heating component, a copper tube box component, a temperature control device and a copper tube component, wherein the copper tube component is arranged inside the copper tube box component, the heating component is arranged inside the copper tube component, and the copper tube box component is arranged inside the heating cabinet;

[0007] The temperature control device includes a first thermostat and a second thermostat, which are detachably connected to the outer end surface of the heating cabinet and are used to detect the temperature inside the copper tube box component and the outlet end of the copper tube component respectively, and the extended tube body of the copper tube component is detachably connected to the secondary cleaning machine.

[0008] As a further improvement of the present invention, the copper tube component includes a spiral copper tube, the spiral copper tube body passes through the copper tube box component and the wall of the copper tube box component and extends to the outside of the copper tube box component, the extended tube body of the spiral copper tube has at least two ends, one end of the tube body is an air inlet pipe, and the other end of the tube body is an air outlet pipe, and the air inlet pipe and the air outlet pipe are both threadedly connected to the secondary cleaning machine.

[0009] As a further improvement of the utility model, a solenoid valve is further provided on the air intake pipe, and the solenoid valve is screwed on the air intake pipe.

[0010] As a further improvement of the present invention, the copper tube box component includes a first copper tube box outer cover, a second copper tube box outer cover and a copper tube box outer shell. The copper tube box outer shell is a cylinder with openings at both ends. The first copper tube box outer cover and the second copper tube box outer cover are respectively screwed on the two end surfaces of the copper tube box outer shell, and the second copper tube box outer cover is also provided with a through hole, and the heating cabinet is also provided with an air outlet corresponding to the through hole.

[0011] As a further improvement of the present invention, the copper tube box component also includes a copper tube box outer shell cover, which is arranged between the second copper tube box outer cover and the heating box cabinet, and is screwed to the end face of the second copper tube box outer cover. An insulating pad is also arranged between the copper tube box outer shell cover and the second copper tube box outer cover.

[0012] As a further improvement of the utility model, a second support seat is arranged at the bottom of the copper tube box component. There are at least four second support seats, which are respectively arranged at the four corners of the bottom surface of the second support seat. The bottom surface of the second support seat is in conflict with the bottom surface of the heating box cabinet.

[0013] As a further improvement of the present invention, the heating component includes a first heating rod and a second heating rod, and the first heating rod and the second heating rod are both located in the spiral inner cavity of the spiral copper tube, wherein the first heating rod is screwed to the inner end surface of the outer cover of the first copper tube box, and the second heating rod is screwed to the inner end surface of the outer cover of the second copper tube box.

[0014] As a further improvement of the present invention, the heating cabinet comprises a first cabinet cover, a second cabinet cover and a cabinet shell, both end surfaces of the cabinet shell are open, and the first cabinet cover and the second cabinet cover are respectively screwed to the two end surfaces of the cabinet shell.

[0015] As a further improvement of the utility model, the inner cavity separated by the copper tube box component and the heating cabinet is a heat-insulating cavity, and the interior of the heat-insulating cavity is filled with heat-insulating cotton.

[0016] As a further improvement of the present invention, a first support seat is further provided at the bottom of the heating cabinet, and at least four first support seats are provided and are arranged at the four corners of the bottom surface of the heating cabinet.

[0017] Compared with the prior art, the technical solution provided by the utility model has the following advantages and effects:

[0018] 1. In this application, the air inlet and outlet pipes in the copper tube component are connected to the secondary cleaning machine by threaded connection. This threaded connection greatly facilitates the disassembly and connection operation between the compressed gas heating device and the secondary cleaning machine. In addition, in order to effectively monitor the temperature inside the copper tube box component and the air outlet of the copper tube component, the first thermostat and the second thermostat are fixed to the end face of the heating cabinet by threaded connection. Both are equipped with high-precision sensors for real-time detection of temperature data. Subsequently, the temperature is effectively managed through the precise regulation of the first thermostat and the second thermostat. In the process of temperature monitoring and regulation, the first thermostat and the second thermostat play a vital role. They are not only responsible for real-time temperature data collection, but also automatically adjust according to the preset temperature range to ensure that the temperature inside the copper tube component and the copper tube box component is always maintained within a suitable range. Specifically, when the temperature exceeds the set range, the thermostat will immediately start the corresponding heating or cooling mechanism to quickly adjust the temperature to the ideal state. This automatic adjustment function not only improves work efficiency, but also reduces the risk of equipment damage that may be caused by excessively high or low temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative labor.

[0020] Figure 1 It is an axonometric drawing of the utility model.

[0021] Figure 2 It is an axonometric view of the utility model from another angle.

[0022] Figure 3 It is the front view of the utility model.

[0023] Figure 4 It is a right view of the utility model.

[0024] Figure 5 yes Figure 4 Section view along the cutting symbol AA.

[0025] Figure 6 It is an axonometric drawing of the hidden heating cabinet components of the utility model.

[0026] In the figure: 1. solenoid valve; 2. heating cabinet; 201. first cabinet cover; 202. second cabinet cover; 203. cabinet shell; 3. first support seat; 4. temperature control device; 401. first thermostat; 402. second thermostat; 5. copper tube component; 501. spiral copper tube; 502. air inlet pipe; 503. air outlet pipe; 6. second support seat; 7. insulation chamber; 8. heating component; 801. first heating rod; 802. second heating rod; 9. copper tube box component; 901. copper tube box shell cover; 902. first copper tube box outer cover; 903. second copper tube box outer cover; 904. copper tube box shell; 10. insulating pad. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0029] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0030] In the description of this application, it should be noted that if the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the product of the application is usually placed when in use. It is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, if the terms "first", "second", etc. appear in the description of this application, they are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0031] In addition, if the terms "horizontal" or "vertical" appear in the description of this application, it does not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0032] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0033] Example:

[0034] A novel compressed gas heating device includes a secondary cleaning machine, a heating cabinet 2, a heating component 8, a copper tube box component 9, a temperature control device 4 and a copper tube component 5, wherein the copper tube component 5 is arranged inside the copper tube box component 9, the heating component 8 is arranged inside the copper tube component 5, and the copper tube box component 9 is arranged inside the heating cabinet 2;

[0035] The temperature control device 4 includes a first thermostat 401 and a second thermostat 402, which are detachably connected to the outer end surface of the heating cabinet 2, and are used to detect the temperature inside the copper tube box component 9 and the outlet end of the copper tube component 5, respectively, and the extended tube body of the copper tube component 5 is detachably connected to the secondary cleaning machine.

[0036] It is explained that the copper tube component 5 includes a spiral copper tube 501, and the body of the spiral copper tube 501 penetrates the copper tube box component 9 and the wall of the copper tube box component 9 and is extended outside the copper tube box component 9. The extended body of the spiral copper tube 501 has at least two ends, wherein one end of the tube body is an air inlet pipe 502, and the other end of the tube body is an air outlet pipe 503, wherein the air inlet pipe 502 and the air outlet pipe 503 are both threadedly connected to the secondary cleaning machine, wherein the air inlet pipe 502 and the air outlet pipe 503 in the copper tube component 5 are connected to the secondary cleaning machine by a threaded connection method, and this threaded connection method greatly facilitates the disassembly and connection operations between the compressed gas heating device and the secondary cleaning machine.

[0037] Brief description of working principle:

[0038] By applying electric energy to the heating component 8, its heating function is realized. In this process, the first thermostat 401 and the second thermostat 402 work together to accurately control the temperature of the heating component 8 to ensure that it operates within a safe and stable range. Subsequently, the heat generated by the heating component 8 is effectively transferred to the copper tube component 5 to achieve heating of the copper tube component 5. When compressed air enters from the air inlet pipe 502 of the copper tube, it flows through the heated copper tube component 5. In this process, the compressed air is effectively heated through heat exchange with the copper tube component 5. Finally, when the heated compressed air is needed, the heated compressed gas can be smoothly discharged through the air outlet pipe 503 for subsequent use.

[0039] It is explained that in order to effectively monitor the temperature inside the copper tube box component 9 and the outlet pipe 503 of the copper tube component 5, the first thermostat 401 and the second thermostat 402 are fixed to the end face of the heating cabinet 2 by screw connection, and both are equipped with high-precision sensors for real-time detection of temperature data. Subsequently, the first thermostat 401 and the second thermostat 402 are precisely controlled to achieve effective management of temperature. In the process of temperature monitoring and adjustment, the first thermostat 401 and the second thermostat 402 play a vital role. They are not only responsible for real-time collection of temperature data, but also automatically adjust according to the preset temperature range to ensure that the temperature inside the copper tube component 5 and the copper tube box component 9 is always maintained within a suitable range. Specifically, when the temperature exceeds the set range, the thermostat will immediately start the corresponding heating or cooling mechanism to quickly adjust the temperature to the ideal state. This automatic adjustment function not only improves work efficiency, but also reduces the risk of equipment damage that may be caused by excessively high or low temperatures.

[0040] It is worth mentioning that the design of thermostats also takes into full consideration the convenience and safety of use. They adopt an easy-to-use interface and clear indicator lights, allowing users to easily monitor and adjust the temperature. At the same time, the thermostats also have over-temperature protection and short-circuit protection functions to ensure that the power supply can be automatically cut off in abnormal situations to prevent equipment damage and safety accidents.

[0041] Combined with the accompanying drawings Figure 1-Figure 6 The air inlet pipe 502 is also provided with a solenoid valve 1, which is screwed on the air inlet pipe 502. The solenoid valve 1 controls the entry of compressed air into the air inlet pipe 502, while ensuring the stability and flexibility of the system operation. When the solenoid valve 1 is opened, the compressed air can smoothly enter the air inlet pipe 502, providing the required pressure and flow for the system. When the solenoid valve 1 is closed, the airflow in the air inlet pipe 502 is cut off, realizing the precise control of the compressed air flow.

[0042] Combined with the accompanying drawings Figure 1-Figure 6 The copper tube box component 9 includes a first copper tube box outer cover 902, a second copper tube box outer cover 903 and a copper tube box shell 904. The copper tube box shell 904 is a cylinder with openings at both ends. The first copper tube box outer cover 902 and the second copper tube box outer cover 903 are respectively screwed on the two end surfaces of the copper tube box shell 904, and the second copper tube box outer cover 903 is also provided with a through hole. The heating cabinet 2 is also provided with an air outlet corresponding to the through hole. The copper tube box component 9 also includes a copper tube box shell cover 901, which is arranged between the second copper tube box outer cover 903 and the heating cabinet 2, and is screwed on the end surface of the second copper tube box outer cover 903. An insulating pad 10 is also arranged between the copper tube box outer cover 901 and the second copper tube box outer cover 903.

[0043] To explain, first of all, the design of the first copper tube box outer cover 902 and the second copper tube box outer cover 903 not only ensures the sealing of the copper tube box shell 904 and prevents the leakage of heat and gas, but also facilitates the disassembly and maintenance of the copper tube box component 9. The screw connection makes the connection more secure and ensures the stability of the component during use. In particular, the through-hole design on the second copper tube box outer cover 903 provides an outlet for the hot air or steam in the heating cabinet 2, avoiding the potential safety hazards caused by excessive internal pressure. At the same time, the corresponding air outlet on the heating cabinet 2 allows the hot air or steam to be discharged smoothly, maintaining a good ventilation environment inside the cabinet.

[0044] Specifically, the setting of the outer shell cover 901 of the copper tube box not only enhances the overall structural strength of the copper tube box component 9, but also further improves its sealing performance. The insulating pad 10 between the outer shell cover and the second copper tube box outer cover 903 effectively prevents the transfer and loss of heat, ensuring the working efficiency and service life of the component. At the same time, the presence of the insulating pad 10 also plays a role in safety protection, avoiding burns or other safety hazards caused by high temperature.

[0045] Combined with the accompanying drawings Figure 1-Figure 6 A second support seat 6 is arranged at the bottom of the copper tube box component 9. There are at least four second support seats 6, which are respectively arranged at the four corners of the bottom surface of the second support seat 6. The bottom surface of the second support seat 6 is in conflict with the bottom surface of the heating cabinet 2.

[0046] Combined with the accompanying drawings Figure 1-Figure 6 The heating component 8 includes a first heating rod 801 and a second heating rod 802, both of which are located in the spiral inner cavity of the spiral copper tube 501, wherein the first heating rod 801 is screwed to the inner end surface of the first copper tube box outer cover 902, and the second heating rod 802 is screwed to the inner end surface of the second copper tube box outer cover 903.

[0047] It is explained that the design of the first heating rod 801 and the second heating rod 802 is intended to provide a uniform and efficient heating effect, so as to achieve a rapid heating of the fluid in the spiral copper tube 501. By screwing the two heating rods to the inner end surfaces of the first copper tube box outer cover 902 and the second copper tube box outer cover 903, respectively, the heating rods can be tightly combined with the copper tube box, effectively avoiding heat loss and improving the stability of the entire heating system.

[0048] Specifically, during operation, the first heating rod 801 and the second heating rod 802 are driven by electricity to generate heat energy, which is quickly transferred to the fluid in the spiral copper tube 501 to achieve rapid heating. At the same time, the structure of the spiral copper tube 501 helps to increase the heated area of ​​the fluid, further improving the heating efficiency. In addition, the screw connection method of the heating rod makes disassembly and maintenance simple and convenient, reducing maintenance costs.

[0049] Combined with the accompanying drawings Figure 1-Figure 6The heating cabinet 2 includes a first cabinet cover 201, a second cabinet cover 202 and a cabinet shell 203. The two end surfaces of the cabinet shell 203 are open. The first cabinet cover 201 and the second cabinet cover 202 are respectively screwed to the two end surfaces of the cabinet shell 203. The inner cavity separated by the copper tube box component 9 and the heating cabinet 2 is a heat preservation cavity 7. The heat preservation cavity 7 is filled with heat preservation cotton. The bottom of the heating cabinet 2 is also provided with a first support seat 3. At least four first support seats 3 are provided and are arranged at the four corners of the bottom surface of the heating cabinet 2.

[0050] It is explained that the first cabinet cover 201 and the second cabinet cover 202 are fixed to the two end faces of the cabinet shell 203 by screwing. This structure is not only convenient for disassembly and assembly, but also can effectively ensure the sealing of the cabinet and prevent heat leakage. At the same time, the screwing method also enhances the stability of the cabinet as a whole, so that it can remain stable during operation and is not prone to shaking. In addition, the inner cavity separated by the copper tube box component 9 and the heating cabinet 2 is the insulation cavity 7. This design enables the insulation cavity 7 to effectively isolate the external temperature and maintain the internal temperature stable. The insulation cavity 7 is filled with insulation cotton, which further enhances the insulation effect and reduces the loss of heat. The softness and filling of the insulation cotton make full use of the internal space of the insulation cavity 7, and can also effectively prevent the direct transfer of heat, thereby improving the heating efficiency.

[0051] It is further worth noting that a first support seat 3 is also provided at the bottom of the heating cabinet 2. These support seats not only support the entire heating cabinet 2, but also reduce the direct contact between the cabinet and the ground to a certain extent, thereby avoiding the corrosion of the cabinet by ground moisture. At the same time, at least four first support seats 3 are provided, and are arranged at the four corners of the bottom surface of the heating cabinet 2. This layout makes the support of the cabinet more uniform and stable, avoiding the safety hazards caused by unstable support.

[0052] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A novel compressed gas heating device, including a secondary cleaning machine, characterized in that: It also comprises a heating cabinet (2), a heating component (8), a copper tube box component (9), a temperature control device (4) and a copper tube component (5), wherein the copper tube component (5) is arranged inside the copper tube box component (9), the heating component (8) is arranged inside the copper tube component (5), and the copper tube box component (9) is arranged inside the heating cabinet (2); The temperature control device (4) comprises a first thermostat (401) and a second thermostat (402), wherein the first thermostat (401) and the second thermostat (402) are respectively detachably connected to the outer end surface of the heating cabinet (2) and are respectively used to detect the temperature inside the copper tube box component (9) and the outlet end of the copper tube component (5), and the extended tube body of the copper tube component (5) is detachably connected to the secondary cleaning machine.

2. The novel compressed gas heating device according to claim 1 is characterized in that: The copper tube component (5) comprises a spiral copper tube (501), the tube body of the spiral copper tube (501) passes through the copper tube box component (9) and the wall of the copper tube box component (9) and is extended to the outside of the copper tube box component (9), and the extended tube body of the spiral copper tube (501) has at least two ends, one end of which is an air inlet pipe (502) and the other end of which is an air outlet pipe (503), and the air inlet pipe (502) and the air outlet pipe (503) are both threadedly connected to the secondary cleaning machine.

3. The novel compressed gas heating device according to claim 2 is characterized in that: The air intake pipe (502) is also provided with a solenoid valve (1), and the solenoid valve (1) is screwed onto the air intake pipe (502).

4. The novel compressed gas heating device according to claim 3 is characterized in that: The copper tube box component (9) comprises a first copper tube box outer cover (902), a second copper tube box outer cover (903) and a copper tube box outer shell (904); the copper tube box outer shell (904) is a cylinder with openings at both ends; the first copper tube box outer cover (902) and the second copper tube box outer cover (903) are respectively screwed to the two end surfaces of the copper tube box outer shell (904); the second copper tube box outer cover (903) is also provided with a through hole; and the heating cabinet (2) is also provided with an air outlet corresponding to the through hole.

5. The novel compressed gas heating device according to claim 4 is characterized in that: The copper tube box component (9) further comprises a copper tube box outer shell (901), wherein the copper tube box outer shell (901) is arranged between the second copper tube box outer cover (903) and the heating cabinet (2), and is screwed to the end surface of the second copper tube box outer cover (903), and an insulating pad (10) is also arranged between the copper tube box outer shell (901) and the second copper tube box outer cover (903).

6. The novel compressed gas heating device according to claim 5 is characterized in that: A second support seat (6) is arranged at the bottom of the copper tube box component (9), and at least four second support seats (6) are arranged, and are respectively arranged at the four corners of the bottom surface of the second support seat (6), and the bottom surface of the second support seat (6) is in contact with the inner bottom surface of the heating cabinet (2).

7. The novel compressed gas heating device according to claim 6 is characterized in that: The heating component (8) includes a first heating rod (801) and a second heating rod (802), wherein the first heating rod (801) and the second heating rod (802) are both located in the spiral inner cavity of the spiral copper tube (501), wherein the first heating rod (801) is screwed onto the inner end surface of the first copper tube box outer cover (902), and the second heating rod (802) is screwed onto the inner end surface of the second copper tube box outer cover (903).

8. The novel compressed gas heating device according to any one of claims 1 to 7, characterized in that: The heating cabinet (2) comprises a first cabinet cover (201), a second cabinet cover (202) and a cabinet shell (203); both end surfaces of the cabinet shell (203) are open; the first cabinet cover (201) and the second cabinet cover (202) are respectively screwed to the two end surfaces of the cabinet shell (203).

9. The novel compressed gas heating device according to claim 8 is characterized in that: The inner cavity separated by the copper tube box component (9) and the heating cabinet (2) is a heat preservation cavity (7), and the heat preservation cavity (7) is filled with heat preservation cotton.

10. The novel compressed gas heating device according to claim 9 is characterized in that: A first support seat (3) is also provided at the bottom of the heating cabinet (2), and at least four first support seats (3) are provided and are arranged at the four corners of the bottom surface of the heating cabinet (2).

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