Polycrystalline silicon reduction tail gas cooler

Abstract

The utility model discloses a polycrystalline silicon reduction tail gas cooler, which mainly comprises a cooling part and a jacket part, the cooling part comprises a heat exchange shell, a tube box seal head, a U-shaped tube bundle, a baffle plate, a high-temperature tail gas inlet, a low-temperature tail gas outlet, a 1 # circulating water feeding port and a 1 # circulating water return port; and the jacket part comprises a jacket shell, a 2 # circulating water feeding port, a 2 # circulating water return port and a high-temperature tail gas inlet jacket port. The equipment can effectively recover the tail gas heat at the outlet of the reduction furnace, and has the characteristics of compact structure, small occupied area and the like.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical equipment and relates to a polysilicon reduction tail gas cooler. Background Art

[0002] In the Siemens polysilicon production, the reduction process is to mix hydrogen and high-purity trichlorosilane in a certain proportion. The resulting mixed gas is sent to the reduction furnace, and the temperature of the silicon rod or silicon core is as high as 1050℃~1150℃ by electric heating. A chemical reaction is carried out on its surface, resulting in the generation of solid silicon and accumulation on the surface of the silicon rod or silicon core. The outlet temperature of the reduction furnace is generally above 500℃. Because it needs to be cooled to below 0℃ in the tail gas recovery section, this part of the heat needs to be used reasonably, and it is necessary to ensure that it does not liquefy when entering the tail gas recovery section, causing liquid accumulation in the pipeline. Therefore, the temperature entering the tail gas recovery section cannot be too low, and is generally controlled between 50 and 60℃. In order to reduce the export material grade, a water-cooled jacket pipe is generally installed at the outlet of the reduction furnace, and the jacket water of the furnace is used for cooling. The jacket water outlet temperature is set to be the same as the furnace water outlet temperature, and the tail gas temperature is reduced to about 300℃.

[0003] Usually, the water jacket in this process is a single-tube heat exchanger, which often requires a longer jacket and occupies a larger area overall. Summary of the invention

[0004] The utility model aims to provide a polysilicon reduction tail gas cooler to address the deficiencies in the prior art. The cooler can effectively recover the heat of the tail gas at the outlet of the reduction furnace and has the characteristics of compact structure, small footprint, etc.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] A polysilicon reduction tail gas cooler comprises a cooling part and a jacket part; the lower part of the cooling part is located in the inner cavity of the jacket part, and the bottom of the cooling part is connected to the output end of the high-temperature tail gas.

[0007] In the technical solution of the utility model: a 2# circulating water upper water inlet and a 2# circulating water return water inlet are respectively arranged on the jacket part.

[0008] In the technical solution of the utility model: a head is arranged at the upper part of the cooling part, a heat exchange shell is arranged at the lower part, and a U-shaped tube bundle is arranged in the heat exchange shell.

[0009] In the technical solution of the utility model: baffles are arranged at medium or unequal heights in the heat exchange shell.

[0010] In the technical solution of the utility model: a 1# circulating water upper inlet and a 1# circulating water return inlet are arranged on the sealing head.

[0011] In the technical solution of the utility model: a low-temperature tail gas outlet is arranged on the upper part of the heat exchange shell.

[0012] In some specific technical solutions, the polysilicon reduction tail gas cooler includes a cooling part and a jacket part. The cooling part includes a heat exchange shell, a pipe box head, a U-shaped tube bundle, a baffle, a high-temperature tail gas inlet, a low-temperature tail gas outlet, a 1# circulating water inlet and a 1# circulating water return port; the jacket part includes a jacket shell, a 2# circulating water inlet and a 2# circulating water return port and a high-temperature tail gas inlet jacket port.

[0013] Furthermore, the cooling part includes a heat exchange shell, a pipe box head, a U-shaped tube bundle, a baffle, a high-temperature exhaust gas inlet, a low-temperature exhaust gas outlet, a 1# circulating water inlet and a 1# circulating water return outlet.

[0014] Furthermore, the jacket part includes a jacket shell, a 2# circulating water upper inlet, a 2# circulating water return inlet, and a high-temperature tail gas inlet jacket port.

[0015] Furthermore, the shell of the jacket part is located outside the shell of the cooling part.

[0016] Furthermore, the high-temperature exhaust gas inlet jacket opening is located on the outside of the high-temperature exhaust gas inlet and is connected by welding or bolts.

[0017] The beneficial effects of the utility model are as follows: the polysilicon reduction tail gas cooler is mainly composed of a cooling part and a jacket part, it can effectively recover the tail gas heat at the reduction furnace outlet, and has the characteristics of compact structure, small footprint, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0019] In the figure: 1-cooling part, 2-jacket part, 101-heat exchange shell, 102-tube box head, 103-U-tube bundle, 104-baffle, 105-high-temperature exhaust gas inlet, 106-low-temperature exhaust gas outlet, 107-1# circulating water inlet, 108-1# circulating water return outlet, 201-jacket shell, 202-2# circulating water inlet, 203-2# circulating water return outlet, 204-high-temperature exhaust gas inlet jacket outlet. DETAILED DESCRIPTION

[0020] The utility model is described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] like Figure 1 As shown, a polysilicon reduction exhaust gas cooler comprises a cooling part 1 and a jacket part 2; the lower part of the cooling part 1 is located in the inner cavity of the jacket part 2, and the bottom of the cooling part 1 is connected to the output end of the high-temperature exhaust gas.

[0022] The jacket part 2 is provided with a 2# circulating water inlet 202 and a 2# circulating water return inlet 203. The cooling part 1 is provided with a head 102 at the top and a heat exchange shell 101 at the bottom. The heat exchange shell 101 is provided with a U-shaped tube bundle 103. The heat exchange shell 101 is provided with a baffle 104 at a medium or unequal height. The head 102 is provided with a 1# circulating water inlet 107 and a 1# circulating water return inlet 108. The upper part of the heat exchange shell 101 is provided with a low-temperature exhaust gas outlet 106.

[0023] The working process of the utility model is as follows: the high-temperature tail gas from the reduction furnace outlet enters the heat exchange shell, first exchanges heat with the jacket and then exchanges heat with the heat exchange tube bundle, is cooled to become low-temperature tail gas and then sent out. Circulating cooling water is introduced into both the jacket heat exchange and the U-shaped tube bundle as a heat removal medium.

[0024] The specific implementation process is as follows: 1000kg / h high-temperature tail gas (temperature is 500℃, the main medium is SiHCl3, SiH2Cl2, HCL, SiCl4) from the reduction furnace outlet enters the heat exchange shell, first exchanges heat with the jacket and then exchanges heat with the heat exchange tube bundle, and is cooled to 300℃ low-temperature tail gas before being sent out. 25000kg / h and 45000kg / h of circulating cooling water are respectively introduced into the jacket heat exchange and U-shaped tube bundle as heat removal medium.

[0025] The polysilicon reduction tail gas cooler designed by the utility model is mainly composed of a cooling part and a jacket part, which can effectively recover the tail gas heat at the reduction furnace outlet and has the characteristics of compact structure, small footprint, etc.

[0026] The above embodiments and descriptions are only for explaining the principles of the invention, and do not limit the protection scope of the invention. Without departing from the spirit and scope of the invention, the invention may be subject to various changes and improvements, which fall within the scope of the invention. The parts not covered by the invention are the same as the prior art or can be implemented by the prior art.

Claims

1. A polysilicon reduction tail gas cooler, characterized in that: It comprises a cooling part (1) and a jacket part (2); The lower part of the cooling part (1) is located in the inner cavity of the jacket part (2), and the bottom of the cooling part (1) is connected to the output end of the high-temperature exhaust gas; The jacket part (2) is provided with a 2# circulating water inlet (202) and a 2# circulating water return outlet (203). The cooling part (1) is provided with a head (102) at the upper part and a heat exchange shell (101) at the lower part, and a U-shaped tube bundle (103) is provided in the heat exchange shell (101).

2. The polysilicon reduction tail gas cooler according to claim 1, characterized in that: The heat exchange shell (101) is provided with baffles (104) at medium or unequal heights.

3. The polysilicon reduction tail gas cooler according to claim 1, characterized in that: The end cap (102) is provided with a 1# circulating water inlet (107) and a 1# circulating water return outlet (108).

4. The polysilicon reduction tail gas cooler according to claim 1, characterized in that: A low-temperature tail gas outlet (106) is provided at the upper portion of the heat exchange shell (101).

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