Low-leakage high-efficiency heat exchange tube of trichlorosilane synthetic furnace

Abstract

The utility model discloses a low-leakage high-efficiency heat exchange tube of a trichlorosilane synthetic furnace, which belongs to the technical field of polycrystalline silicon production and comprises a high-efficiency heat exchange tube arranged in the synthetic furnace and a cooling water jacket arranged outside the synthetic furnace. One end of the high-efficiency heat exchange pipe extends into the synthetic furnace, the other end of the high-efficiency heat exchange pipe extends into the cooling water jacket, the high-efficiency heat exchange pipe is filled with a liquid-phase working medium, the end, located in the synthetic furnace, of the high-efficiency heat exchange pipe is conveyed to the other end of the high-efficiency heat exchange pipe through steam formed by heating evaporation with latent heat of vaporization, and after being cooled by the cooling water jacket, the liquid-phase working medium is cooled; and then the condensed liquid-phase working medium is returned into the furnace again through the capillary action, and circulating heat energy export is carried out in this way. According to the utility model, the high-efficiency heat exchange tube is adopted to replace an original cold beam tube to carry out temperature control on the trichlorosilane synthetic furnace, and is matched with the cooling water jacket filled with circulating cooling water, and repeated circulation of the hot end in the furnace and the cold end outside the furnace is carried out through capillary action, so that excessive heat energy in the furnace can be stably led out.

Description

Technical Field

[0001] The utility model relates to a heat transfer tube for a trichlorosilane synthesis furnace, in particular to a low-leakage and high-efficiency heat exchange tube for a trichlorosilane synthesis furnace. Background Art

[0002] The primary reaction medium in a trichlorosilane synthesis furnace is hydrogen chloride, which reacts with silicon powder to produce trichlorosilane, with other products, such as dichlorosilane and silicon tetrachloride, also produced. Currently, temperature control in trichlorosilane synthesis furnaces is achieved by installing a certain number of cooling tubes within the furnace. The primary media within these cooling tubes are hot water and steam. These cooling tubes are jacketed with cooling water. Water enters through the inner tube and evaporates from the bottom to the outer tube, dissipating excess heat within the furnace and controlling the reaction temperature below 350°C, thereby increasing the trichlorosilane conversion rate. As in the prior art, patent CN209802174U discloses a cooling tube assembly for a trichlorosilane synthesis furnace, and its technical solution is as follows: The utility model discloses a cooling tube assembly for a trichlorosilane synthesis furnace, which includes several cooling tubes arranged in a furnace body of the trichlorosilane synthesis furnace. The cooling tubes are arranged in a circular ring shape in the furnace body, and support rings are provided on the outer surface of the cooling tubes. The support rings provided on the outer surface of adjacent cooling tubes located on the same horizontal plane are connected together to form an outer support ring and an inner support ring. The inner support ring and the outer support ring located on the same horizontal plane are connected together, and a movable support member is provided on the support ring of the outer cooling tube.

[0003] The following phenomena exist during the operation of existing trichlorosilane synthesis furnaces: First, the raw silicon powder in the furnace is fluidized by the airflow generated by hydrogen chloride passing through the bottom nozzle. The reaction between silicon powder and hydrogen chloride to produce trichlorosilane is an exothermic reaction. Due to the variation in the particle size and diameter of the raw silicon powder, the fluidization state in the furnace is often poor, and silicon powder accumulates in local areas. The reaction of the accumulated silicon powder will melt the cooling tube, causing a large amount of water to enter the furnace. This water will quickly vaporize due to the high temperature and enter the downstream system, clogging the filters, scrubbers, and pipes of the downstream system, forcing the system to shut down for maintenance, resulting in a large amount of manpower and material resources. Second, the use of cooling water jacketed cooling tubes causes water hammer due to the evaporation of water in the tubes. The steam from the inner tube carries water and hits the bottom of the cooling tube, causing the cooling tube to vibrate, and the welding of the cooling tube to the synthesis furnace body will easily cause cracks and water leakage in the cooling tube. Utility Model Content

[0004] The utility model aims to solve a series of production problems caused by using a cold bundle tube for temperature control in a trichlorosilane synthesis furnace in the prior art, and proposes a high-efficiency heat exchange tube with low leakage effect suitable for the trichlorosilane synthesis furnace.

[0005] In order to achieve the above-mentioned utility model purpose, the technical solution of the utility model is as follows:

[0006] The low-leakage, high-efficiency heat exchange tube of the trichlorosilane synthesis furnace comprises a high-efficiency heat exchange tube arranged in the synthesis furnace and a cooling water jacket arranged outside the synthesis furnace; one end of the high-efficiency heat exchange tube extends into the synthesis furnace, and the other end extends into the cooling water jacket. The interior of the high-efficiency heat exchange tube is filled with a liquid working medium. Steam generated by evaporation at one end of the high-efficiency heat exchange tube located in the synthesis furnace is transported to the other end of the high-efficiency heat exchange tube with latent heat of vaporization. After being cooled by the cooling water jacket, the condensed liquid working medium is returned to the furnace again by capillary action, and heat energy is extracted in a reciprocating cycle.

[0007] Furthermore, the high-efficiency heat exchange tube is connected and fixed to the synthesis furnace body by welding.

[0008] Furthermore, the high-efficiency heat exchange tubes are provided in plurality and are evenly distributed in the synthesis furnace drum.

[0009] Furthermore, a tube clamp is welded inside the synthesis furnace, and a plurality of the high-efficiency heat exchange tubes are fixed on the tube clamp.

[0010] Furthermore, the high-efficiency heat exchange tube is a closed metal tube with internal vacuum, which includes an inner tube and an outer tube. Capillaries connecting the inner tube and the outer tube are provided at both ends of the high-efficiency heat exchange tube.

[0011] Furthermore, the high-efficiency heat exchange tube includes an evaporation section, an insulation section and a condensation section. The evaporation section is located inside the furnace, the condensation section is located in the cooling water jacket outside the furnace, and the insulation section is located between the evaporation section and the condensation section, serving as a functional dividing line between evaporation and condensation.

[0012] Furthermore, the surface of the high-efficiency heat exchange tube is coated with a supersonic thermal spray wear-resistant material.

[0013] The working principle of this utility model is as follows:

[0014] Circulating water of the temperature required for temperature control of the synthesis furnace is introduced into the cooling water jacket. After the evaporation section of the high-efficiency heat exchange tube is heated, the liquid working medium inside it begins to evaporate. The vapor is transported to the condensation section at the other end of the heat pipe with the latent heat of vaporization and releases the latent heat of vaporization. Under the action of the capillary pump, the condensate returns to the evaporation section through the capillary tube, and the cycle repeats, thereby stably conducting away the excess heat energy in the furnace.

[0015] In summary, the utility model has the following advantages:

[0016] 1. This utility model uses high-efficiency heat exchange tubes to replace the original cooling tubes to control the temperature of the trichlorosilane synthesis furnace. The high-efficiency heat exchange tubes are combined with a cooling water jacket with circulating cooling water. Through capillary action, the hot end inside the furnace and the cold end outside the furnace are repeatedly circulated, which can stably discharge the excess heat energy in the furnace.

[0017] 2. The high-efficiency heat exchange tube of the utility model has a closed structure. There is only a small amount of water inside it, and it is not connected to the rear system. Even if one or several heat pipes are burned due to silicon powder accumulation, it will not have a significant impact on the equipment and system, ensuring that the system continues to operate normally and improving system stability.

[0018] 3. Due to its closed structure, the high-efficiency heat exchange tube of the utility model has little or no vibration, which can effectively prevent the generation of cracks at the connection and improve the safety of system operation;

[0019] 4. The surface of the high-efficiency heat exchange tube of the present invention is coated with supersonic thermal spray wear-resistant material, which can increase the service life of the high-efficiency heat exchange tube and reduce the replacement frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the internal structure of the utility model;

[0021] Figure 2 This is a schematic diagram of the thermal cycle of the heat transfer tube of the utility model;

[0022] Figure 3 It is a top view of the utility model;

[0023] In the picture:

[0024] 1. Furnace drum, 2. High-efficiency heat exchange tubes, 3. Cooling water jacket. DETAILED DESCRIPTION

[0025] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0027] 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, it does not need to be further defined or explained in subsequent drawings.

[0028] In the description of this utility model, it should be noted that the terms "upper," "vertical," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the utility model product is typically placed when in use, or are the orientations or positional relationships commonly understood by those skilled in the art. These terms are intended solely to facilitate the description of this utility model and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," etc., etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0029] It should also be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "disposed," "installed," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this utility model based on the specific circumstances.

[0030] The utility model discloses a low-leakage and high-efficiency heat exchange tube 2 for a trichlorosilane synthesis furnace. Figure 1 As shown, it includes a high-efficiency heat exchange tube 2 arranged in the synthesis furnace and a cooling water jacket 3 arranged outside the synthesis furnace. One end of the high-efficiency heat exchange tube 2 is located in the synthesis furnace, and the other end extends into the cooling water jacket 3.

[0031] In this embodiment, the high-efficiency heat exchange tube 2 is structured into three sections: an evaporation section, an adiabatic section, and a condensation section. The evaporation section is located inside the furnace, while the condensation section is located outside the furnace in a cooling water jacket 3. The adiabatic section is located between the evaporation and condensation sections, serving as the functional boundary between evaporation and condensation. During operation, circulating cooling water flows through the cooling water jacket 3 to remove heat removed from the furnace by gravity vacuum. High heat flux density can be input into the evaporation section, while low heat flux density can be output from the condensation section, achieving efficient heat transfer from one end to the other.

[0032] In this embodiment, the high-efficiency heat exchange tube 2 is connected and fixed to the synthesis furnace barrel 1 by welding. The high-efficiency heat exchange tube 2 can be set in multiple pieces according to actual needs and evenly arranged in the barrel to ensure the stability of the temperature in the synthesis furnace. Figure 3 Arrangement shown.

[0033] Preferably, in order to further improve the fixing effect, a plurality of high-efficiency heat exchange tubes 2 are fixed in the synthesis furnace drum 1 in the form of tube clamps.

[0034] In this embodiment, the high-efficiency heat exchange tube 2 is a gravity vacuum heat pipe, and its internal structure is as follows: Figure 2 As shown in . The high-efficiency heat exchange tube 2 is a metal tube with an evacuated interior, consisting of an inner and outer tube. The liquid phase fills the entire tube core. Capillary tubes are provided at both ends of the high-efficiency heat exchange tube 2, connecting the inner and outer tubes. When the liquid phase in the high-efficiency heat exchange tube 2 is heated in the evaporation section and begins to evaporate, the vapor, carrying its latent heat of vaporization, is transported to the condensation section at the other end of the heat pipe, releasing it. Capillary pumping force then causes the condensate to return to the evaporation section through the capillary tube, completing the cycle. This repeated circulation of the high-efficiency heat exchange tube 2 allows for the stable removal of excess heat energy from the furnace.

[0035] In this solution, since the high-efficiency heat exchange tubes 2 are enclosed and not connected to the backend system, they contain only a small amount of water. Even if one or more heat pipes were damaged by silicon powder accumulation, this would not significantly impact the equipment and system, ensuring continued normal operation. Furthermore, since the high-efficiency heat exchange tubes 2 are enclosed, they experience minimal or no vibration, effectively preventing cracks at the joints.

[0036] Furthermore, to extend the service life of the high-efficiency heat exchange tubes 2, the surface of the high-efficiency heat exchange tubes 2 is coated with a supersonic thermal spray wear-resistant material. This supersonic thermal spray wear-resistant material has properties such as wear resistance, corrosion resistance, and high temperature resistance, which can reduce the replacement frequency of the high-efficiency heat exchange tubes. Preferably, the supersonic thermal spray wear-resistant material is applied to the evaporation section of the high-efficiency heat exchange tubes 2.

[0037] The working principle of this utility model is as follows:

[0038] Circulating water of the temperature required for temperature control of the synthesis furnace is introduced into the cooling water jacket. After the evaporation section of the high-efficiency heat exchange tube is heated, the liquid working medium inside it begins to evaporate. The vapor is transported to the condensation section at the other end of the heat pipe with the latent heat of vaporization and releases the latent heat of vaporization. Under the action of the capillary pump, the condensate returns to the evaporation section through the capillary tube, and the cycle repeats, thereby stably conducting away the excess heat energy in the furnace.

[0039] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention falls within the scope of protection of the present invention.

Claims

1. Low leakage and high efficiency heat exchange tube for trichlorosilane synthesis furnace, characterized by: The invention comprises a high-efficiency heat exchange tube (2) arranged in a synthesis furnace and a cooling water jacket (3) arranged outside the synthesis furnace; one end of the high-efficiency heat exchange tube (2) extends into the synthesis furnace, and the other end extends into the cooling water jacket (3); the interior of the high-efficiency heat exchange tube (2) is filled with a liquid phase working medium, and the steam formed by evaporation at one end of the high-efficiency heat exchange tube located in the synthesis furnace is transported to the other end of the high-efficiency heat exchange tube (2) with latent heat of vaporization, and after being cooled by the cooling water jacket (3), the condensed liquid phase working medium is returned to the furnace again by capillary action, and the heat energy is discharged in a reciprocating cycle.

2. The low-leakage and high-efficiency heat exchange tube for a trichlorosilane synthesis furnace according to claim 1, characterized in that: The high-efficiency heat exchange tube (2) and the synthesis furnace drum (1) are connected and fixed by welding.

3. The low-leakage and high-efficiency heat exchange tube for a trichlorosilane synthesis furnace according to claim 1, characterized in that: A plurality of high-efficiency heat exchange tubes (2) are provided and are evenly distributed in the synthesis furnace drum (1).

4. The low-leakage and high-efficiency heat exchange tube for a trichlorosilane synthesis furnace according to claim 3, characterized in that: A tube clamp is welded inside the synthesis furnace, and a plurality of high-efficiency heat exchange tubes (2) are fixed on the tube clamp.

5. The low-leakage and high-efficiency heat exchange tube for a trichlorosilane synthesis furnace according to claim 1, characterized in that: The high-efficiency heat exchange tube (2) is a closed metal tube with an internal vacuum pumped therein, comprising an inner tube and an outer tube. Capillaries are provided at both ends of the high-efficiency heat exchange tube (2) to connect the inner tube and the outer tube.

6. The low-leakage and high-efficiency heat exchange tube for a trichlorosilane synthesis furnace according to claim 1, characterized in that: The high-efficiency heat exchange tube (2) comprises an evaporation section, an insulation section, and a condensation section. The evaporation section is located inside the furnace, the condensation section is located in a cooling water jacket (3) outside the furnace, and the insulation section is located between the evaporation section and the condensation section, serving as a functional dividing line between evaporation and condensation.

7. The low-leakage and high-efficiency heat exchange tube for a trichlorosilane synthesis furnace according to claim 1, characterized in that: The surface of the high-efficiency heat exchange tube (2) is coated with a supersonic thermal spray wear-resistant material.

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