Device for preventing compressor from running with liquid

Abstract

The device for preventing the compressor from running with liquid comprises a first-stage heat exchanger, a second-stage heat exchanger, a third-stage heat exchanger, a separation tank, a condensate tank, an inlet buffer tank, an outlet buffer tank and the compressor, a tube pass outlet of the first-stage heat exchanger is connected with a tube pass inlet of the second-stage heat exchanger, and a tube pass outlet of the second-stage heat exchanger is connected with a tube pass inlet of the third-stage heat exchanger. A tube pass outlet of the third-stage heat exchanger is connected with a separation tank, a liquid phase outlet of the separation tank is connected with a condensate tank, a gas phase outlet of the separation tank is connected with an inlet buffer tank, an outlet of the inlet buffer tank is connected with a compressor, and an outlet of the compressor is connected with an outlet buffer tank; the heat exchange temperatures of the first-stage heat exchanger, the second-stage heat exchanger and the third-stage heat exchanger are sequentially reduced; according to the scheme, through three-stage heat exchange, gas and liquid are separated at a time, then the gas phase enters the compressor, through two-time and four-stage separation, the gas phase entering the compressor almost does not carry a liquid phase, and faults caused by liquid waiting operation of the compressor are avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of polysilicon tail gas separation, in particular to a device for preventing a compressor from running with liquid. Background Art

[0002] In the polysilicon exhaust system, when the exhaust compressor is in operation, the front-end system operates unstably, and the materials with lower boiling points are not completely condensed in the front-end system, causing the compressor inlet buffer tank to be filled with liquid, which easily forms a liquid phase and enters the compressor, causing the compressor to trip and stop due to liquid during operation. Utility Model Content

[0003] In view of the above defects, the utility model proposes a device for preventing the compressor from running with liquid, including a primary heat exchanger, a secondary heat exchanger, a tertiary heat exchanger, a separation tank, a condensate tank, an inlet buffer tank, an outlet buffer tank, and a compressor. The tube-side inlet of the primary heat exchanger is used to introduce exhaust gas, the tube-side outlet of the primary heat exchanger is connected to the tube-side inlet of the secondary heat exchanger, the tube-side outlet of the secondary heat exchanger is connected to the tube-side inlet of the tertiary heat exchanger, the tube-side outlet of the tertiary heat exchanger is connected to the separation tank, the liquid phase outlet of the separation tank is connected to the condensate tank, the gas phase outlet of the separation tank is connected to the inlet buffer tank, the outlet of the inlet buffer tank is connected to the compressor, and the outlet of the compressor is connected to the outlet buffer tank; the tube-side outlet of the primary heat exchanger is also provided with a liquid phase outlet connected to the condensate tank, the tube-side outlet of the secondary heat exchanger is also provided with a liquid phase outlet connected to the condensate tank, and the heat exchange temperatures of the primary heat exchanger, the secondary heat exchanger, and the tertiary heat exchanger are sequentially reduced.

[0004] This solution uses three-stage heat exchangers to cool the tail gas in sequence. The condensed liquid phase is temporarily stored in the condensate tank. The remaining gas phase enters the buffer tank from the separation tank for steady flow, and then enters the compressor for low-pressure compression and delivery. This solution uses three-stage heat exchange to separate gas and liquid once, and then uses the imported buffer tank for slow flow separation. After that, the gas phase enters the compressor. After two or four stages of separation, the gas phase entering the compressor will hardly carry the liquid phase, avoiding failures caused by the compressor waiting for liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 This is a schematic diagram of the structure of this scheme.

[0006] Figure 2 It is a schematic diagram of another preferred embodiment of the import buffer tank.

[0007] Figure 3 This is a schematic diagram of the original buffer tank.

[0008] In the figure: a primary heat exchanger 10, a secondary heat exchanger 20, a tertiary heat exchanger 30, a shell-side discharge pipe 31, a separation tank 40, a condensate tank 50, a gas phase pipeline 51, a first temperature sensor 52, a coil 53, an inlet buffer tank 60, a liquid accumulation bag 61, a mouth 62, a bag body 63, an outlet buffer tank 70, and a compressor 80. DETAILED DESCRIPTION

[0009] See also Figure 1-3 The utility model proposes a device for preventing a compressor from running with liquid, comprising a primary heat exchanger 10, a secondary heat exchanger 20, a tertiary heat exchanger 30, a separation tank 40, a condensate tank 50, an inlet buffer tank 60, an outlet buffer tank 70, and a compressor 80. The pipe inlet of the primary heat exchanger 10 is used to introduce tail gas, the pipe outlet of the primary heat exchanger 10 is connected to the pipe inlet of the secondary heat exchanger 20, the pipe outlet of the secondary heat exchanger 20 is connected to the pipe inlet of the tertiary heat exchanger 30, and the pipe outlet of the tertiary heat exchanger 30 is connected to the separator 40. The separation tank 40 is connected to the condensate tank 50, the gas phase outlet of the separation tank 40 is connected to the import buffer tank 60, the outlet of the import buffer tank 60 is connected to the compressor 80, and the outlet of the compressor 80 is connected to the export buffer tank 70; the tube side outlet of the first-stage heat exchanger 10 is also provided with a liquid phase outlet, which is connected to the condensate tank 50, and the tube side outlet of the second-stage heat exchanger 20 is also provided with a liquid phase outlet, which is connected to the condensate tank 50. The heat exchange temperatures of the first-stage heat exchanger 10, the second-stage heat exchanger 20, and the third-stage heat exchanger 30 are reduced in sequence.

[0010] This solution uses three stages of heat exchangers that lower the heat exchange temperature in sequence to exchange heat and cool the tail gas. The condensed liquid phase is temporarily stored in the condensate tank 50, and the remaining gas phase enters the buffer tank from the separation tank 40 for steady flow, and then enters the compressor 80 for low-pressure compression and delivery. This solution uses three stages of heat exchange to separate gas and liquid once, and then uses the inlet buffer tank 60 for slow flow separation twice, and then the gas phase enters the compressor 80. After two or four stages of separation, the gas phase entering the compressor 80 will hardly carry the liquid phase, thus avoiding the failure caused by the compressor 80 waiting for liquid to run.

[0011] Furthermore, the heat exchange medium of the secondary heat exchanger 20 is chilled water with a temperature of 5-10°C.

[0012] Furthermore, the heat exchange medium of the three-stage heat exchanger 30 is Freon, and the temperature is -15~-25°C.

[0013] Furthermore, the condensate tank 50 is also provided with a gas phase outlet, which is connected to the tube side inlet of the tertiary heat exchanger 30 through a gas phase pipeline 51. The condensate tank 50 stores liquid silane, which contains liquid disilcon. However, since the boiling point of disilcon is extremely low, if the temperature in the condensate tank 50 is improperly controlled and the temperature rises slightly, the disilcon is easy to gasify and form a gas phase. In order to collect and reuse the gas phase and to ensure the stability and safety of the gas pressure in the condensate tank, the gas phase is introduced into the tertiary heat exchanger 30 through a pipeline. Since the secondary heat exchanger 20 uses refrigerated brine with a temperature of 7-8°C, the disilcon may not be cooled into a liquid phase, so it is introduced into the tertiary heat exchanger 30. The tertiary heat exchanger 30 uses Freon with a temperature of minus 20°C, which can quickly and massively cool the disilcon into a liquid phase.

[0014] Furthermore, a first thermometer 52 and a coil 53 are provided in the condensate tank 50, and a shell-side discharge pipe 31 is provided in the three-stage heat exchanger 30. The first thermometer is used to detect the temperature in the condensate tank 50. The coil is arranged inside the condensate tank 50, and the coil is used to pass a cooling medium. The inlet of the coil 53 is connected to the shell-side discharge pipe 31 of the third heat exchanger, and the outlet of the coil is used to discharge the heat exchange medium. In this scheme, the temperature in the condensate tank 50 is detected in real time by the first thermometer. When the temperature is higher than the set value, the control valve is opened to pass the Freon after heat exchange in the shell-side discharge pipe 31 of the third heat exchanger into the coil to cool the condensate tank 50. In a preferred embodiment, the temperature of the Freon after the three-stage heat exchange can still reach about -10°C, and the temperature in the condensate tank 50 is controlled below 8°C, so the Freon after the three-stage heat exchange is sufficient for the coil to heat, reduce the liquid phase temperature, and control or even avoid the gasification of disilcon.

[0015] Furthermore, a liquid accumulation bag 61 is provided at the bottom of the inlet buffer tank 60, and the liquid accumulation bag 61 includes a mouth 62 and a bag body 63, wherein the mouth 62 is connected to the bottom of the liquid accumulation bag 61, and the height of the bag body 63 is lower than the bottom of the buffer tank 60. The gas phase and liquid phase mixture after the three-stage heat exchange enters the gas-liquid separation tank 40, the liquid phase settles to the condensation tank 50, and the gas phase mixed gas enters the compressor 80. This part of the gas phase mixture may contain part of the liquid phase. In order to prevent this part of the liquid phase from entering the compressor 80, the inlet buffer tank 60 is provided, and the liquid phase settled at the bottom of the original flat-bottom buffer tank is easily affected by the flow rate of the gas flow due to its large surface area, and the disilcon therein is gasified again, and the gasified disilcon will carry part of the liquid phase into the compressor 80. Therefore, in order to avoid the vaporization of the liquid phase with a larger surface area at the bottom, this scheme sets up a liquid accumulation bag 61, and deposits the liquid phase into a bag body 63 with a height lower than the bottom and a smaller mouth 62, which greatly reduces the area and probability of contact between the liquid phase and the airflow, and greatly reduces the problem of liquid phase entrainment in secondary vaporization.

[0016] Furthermore, the opening diameter of the mouth 62 is smaller than the diameter of the body 63. The function of the buffer tank is to stabilize the flow of gas before entering the compressor 80, and to deposit and separate part of the liquid phase to prevent the liquid phase from being brought into the compressor 80. In the original design, the bottom of the tank body is used to deposit the liquid phase, but due to the large surface area of ​​the bottom, the large liquid distribution area, and the thin distribution thickness, it is easily affected by the air flow velocity and temperature. Especially for the tail gas of this scheme, most of the components are disilicon. Due to its extremely low boiling point, a small fluctuation in the temperature of the incoming gas will cause the phase state of the liquid phase deposited at the bottom to change, especially disilicon is easily vaporized from the liquid phase, and then entrained into the compressor 80. Therefore, this solution sets up a liquid accumulation bag 61, and the liquid phase entering the tank body first enters the liquid accumulation bag 61 under the action of gravity. The liquid accumulation bag 61 with a smaller mouth 62 can meet the inflow of the liquid phase, and can also greatly reduce the impact of the airflow on the liquid phase in the liquid accumulation bag 61. Even if the flow rate and temperature of the airflow change, the smaller mouth 62 can block these factors from entering, so the liquid phase and the gas phase are better isolated in one direction, that is, the inflow of the liquid phase is guaranteed, and the influence of variable factors of the gas phase is avoided, thereby avoiding the problem of excessive silicon content in the compressor 80 caused by secondary gasification of the liquid phase due to changes in the airflow temperature. A discharge conduit or valve is also set at the bottom of the liquid accumulation bag 61 to discharge the liquid phase regularly.

[0017] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of this patent.

Claims

1. A device for preventing a compressor from running with liquid, characterized in that: The invention comprises a primary heat exchanger, a secondary heat exchanger, a tertiary heat exchanger, a separation tank, a condensate tank, an inlet buffer tank, an outlet buffer tank and a compressor. The tube side inlet of the primary heat exchanger is used for introducing tail gas. The tube side outlet of the primary heat exchanger is connected to the tube side inlet of the secondary heat exchanger. The tube side outlet of the secondary heat exchanger is connected to the tube side inlet of the tertiary heat exchanger. The tube side outlet of the tertiary heat exchanger is connected to the separation tank. The liquid phase outlet of the separation tank is connected to the condensate tank. The gas phase outlet of the separation tank is connected to the inlet buffer tank. The outlet of the inlet buffer tank is connected to the compressor. The outlet of the compressor is connected to the outlet buffer tank. The tube side outlet of the primary heat exchanger is also provided with a liquid phase outlet connected to the condensate tank. The tube side outlet of the secondary heat exchanger is also provided with a liquid phase outlet connected to the condensate tank. The heat exchange temperatures of the primary heat exchanger, the secondary heat exchanger and the tertiary heat exchanger are successively reduced.

2. The device for preventing compressor from running with liquid as claimed in claim 1, characterized in that: The heat exchange medium of the secondary heat exchanger is chilled water with a temperature of 5-10°C.

3. The device for preventing compressor from running with liquid as claimed in claim 1, characterized in that: The heat exchange medium of the three-stage heat exchanger is Freon, and the temperature is -15~-25℃.

4. The device for preventing compressor from running with liquid as claimed in claim 1, characterized in that: The condensate tank is also provided with a gas phase outlet, and the gas phase outlet is connected to the tube side inlet of the three-stage heat exchanger through a gas phase pipeline.

5. The device for preventing compressor from running with liquid as claimed in claim 4, characterized in that: A first temperature sensor and a coil are also provided in the condensate tank, and a shell-side discharge pipe is also provided in the third-stage heat exchanger. The first temperature sensor is used to detect the temperature in the condensate tank. The coil is arranged inside the condensate tank, and the coil is used to pass a cooling medium. The inlet of the coil is connected to the shell-side discharge pipe of the third heat exchanger, and the outlet of the coil is used to discharge the heat exchange medium.

6. The device for preventing compressor from running with liquid as claimed in claim 5, characterized in that: A liquid accumulation bag is arranged at the bottom of the inlet buffer tank, and the liquid accumulation bag comprises a mouth and a bag body, wherein the mouth is communicated with the bottom of the liquid accumulation bag, and the height of the bag body is lower than the height of the bottom of the buffer tank.

7. The device for preventing the compressor from running with liquid as claimed in claim 6, characterized in that: The mouth opening diameter is smaller than the diameter of the bag body.

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