A phosphorus trichloride separation device

Abstract

This utility model discloses a phosphorus trichloride separation device, comprising: a primary separator, a secondary separator, a first liquid level measuring device, a second liquid level measuring device, a controller, a first liquid discharge control valve, and a second liquid discharge control valve. The primary separator has a tail gas inlet and a first gas outlet at its top, and a first liquid outlet at its bottom. The tail gas inlet is adapted to receive a mixture containing phosphorus trichloride gas and liquid. The secondary separator has a separation inlet and a tail gas outlet at its top, the separation inlet being connected to the first gas outlet. The secondary separator is adapted to receive gas from the primary separator, and a second liquid outlet is located at its bottom. This utility model achieves more efficient gas-liquid separation while also featuring liquid level detection to prevent liquid overflow and improve production safety.

Description

Technical Field

[0001] This utility model relates to a phosphorus trichloride separation device, belonging to the field of chemical technology. Background Technology

[0002] Currently, in the phosphorus trichloride production process, after the phosphorus trichloride gas from the phosphorus trichloride washing tower is condensed, the exhaust gas contains a small amount of liquid and gaseous phosphorus trichloride, as well as a small amount of phosphorus slag and tar. Generally, a single separator is used to separate the gas and liquid in this exhaust gas. The liquid phosphorus trichloride is discharged from the bottom into the storage tank, while the non-condensable gas is discharged from the top into the exhaust gas absorption tower. The phosphorus trichloride in the separator is observed through the liquid level (glass sight glass) and is discharged periodically.

[0003] However, existing single-separator units have several technical drawbacks. First, when production fluctuations lead to poor condensation, the amount of phosphorus trichloride entrained in the exhaust gas increases, eventually entering the separator. Second, the exhaust gas contains tar and phosphorus residue, causing blockages in the level sight glass and the bottom outlet pipe, resulting in phosphorus trichloride overflowing from the top of the separator. Furthermore, the subsequent exhaust gas absorption tower uses water as the absorbent, and the interaction of water with large amounts of phosphorus trichloride poses an explosion risk. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to overcome the defects of the prior art and provide a phosphorus trichloride separation device that can achieve more efficient gas-liquid separation, while also having liquid level detection to prevent liquid overflow and improve production safety.

[0005] To solve the above-mentioned technical problems, the technical solution of this utility model is: a phosphorus trichloride separation device, comprising:

[0006] A primary separator, wherein the top of the primary separator is provided with an exhaust gas inlet and a first gas outlet, and the bottom of the primary separator is provided with a first liquid outlet, and the exhaust gas inlet is suitable for introducing the exhaust gas after phosphorus trichloride gas has been condensed;

[0007] A secondary separator is provided with a separation inlet and an exhaust outlet at the top. The separation inlet is connected to the first gas outlet. The secondary separator is adapted to receive gas separated by the primary separator. A second liquid outlet is provided at the bottom of the secondary separator.

[0008] A first liquid level measuring device is installed on the first-stage separator and used to collect the liquid level in the first-stage separator;

[0009] A second liquid level measuring device is disposed on the secondary separator and used to collect the liquid level in the secondary separator;

[0010] A controller, which is connected to the first liquid level measuring device and the second liquid level measuring device respectively;

[0011] The first liquid discharge control valve is installed on the liquid discharge pipeline of the first liquid outlet and is connected to the controller.

[0012] The second liquid discharge control valve is installed on the liquid discharge pipeline of the second liquid outlet and is connected to the controller.

[0013] The controller is adapted to control the operation of the first liquid discharge control valve based on the liquid level collected by the first liquid level measuring device and to control the operation of the second liquid discharge control valve based on the liquid level collected by the second liquid level measuring device.

[0014] Furthermore, a specific structure of a first liquid level measuring device is provided, the first liquid level measuring device comprising:

[0015] The first differential pressure transmitter is connected to the upper and lower parts of the side wall of the first-stage separator through a first pressure tapping pipe, and is connected to the controller.

[0016] The first radar level gauge is installed on the top of the first-stage separator, and the probe portion of the first radar level gauge extends into the first-stage separator. The first radar level gauge is connected to the controller.

[0017] The controller is adapted to control the operation of the first liquid discharge control valve according to the liquid level of the first differential pressure transmitter or the liquid level of the first radar level gauge.

[0018] Furthermore, a specific structure for a second liquid level measuring device is provided, the second liquid level measuring device comprising:

[0019] The second differential pressure transmitter is connected to the upper and lower parts of the side wall of the secondary separator through the second pressure tapping pipe, and is connected to the controller.

[0020] The second radar level gauge is installed on top of the secondary separator, and the probe portion of the second radar level gauge extends into the secondary separator. The second radar level gauge is connected to the controller.

[0021] The controller is adapted to control the operation of the second liquid discharge control valve according to the liquid level of the second differential pressure transmitter or the liquid level of the second radar level gauge.

[0022] Furthermore, the phosphorus trichloride separation equipment also includes a tail gas absorption tower, the inlet of which is connected to the tail gas outlet.

[0023] Furthermore, the phosphorus trichloride separation equipment also includes a phosphorus trichloride storage tank, which is provided with a first liquid inlet and a second liquid inlet. The first liquid inlet is connected to the first liquid outlet, and the second liquid inlet is connected to the second liquid outlet.

[0024] Furthermore, the phosphorus trichloride separation equipment also includes a feed pipeline, a discharge pipeline, and a maintenance and switching system. The maintenance and switching system includes:

[0025] The first feed shut-off valve has one end connected to the feed pipeline and the other end connected to the exhaust gas inlet. The first feed shut-off valve is also connected to the controller.

[0026] The second discharge control valve has one end connected to the exhaust port and the other end connected to the discharge pipeline. The second discharge control valve is also connected to the controller.

[0027] A bypass pipeline, one end of which has a converging end and the other end is connected to the discharge pipeline. The converging end is connected to the inlet pipeline through a branch pipeline. A branch control valve is provided in the branch pipeline and is connected to a controller.

[0028] A three-way switching valve is provided with a first port, a second port and a third port. The first port is connected to the first gas outlet of the first separator, the second port is connected to the collection end, and the third port is connected to the separation inlet of the secondary separator. The three-way switching valve is connected to a controller.

[0029] A bypass control valve is connected in a bypass pipeline and is connected to a controller.

[0030] By adopting the above technical solution, this utility model has the following beneficial effects:

[0031] In this invention, during operation, the condensed phosphorus trichloride gas enters the primary separator through the exhaust gas inlet. Gas-liquid separation occurs inside the primary separator, with the separated liquid discharged through the first liquid outlet and the separated gas discharged from the top through the first gas outlet and entering the separation inlet of the secondary separator. Inside the secondary separator, the gas from the primary separator undergoes further separation, with the remaining liquid discharged through the second liquid outlet and non-condensable gases discharged through the exhaust outlet. A first liquid level measuring device detects the liquid level in the primary separator and sends a first liquid level detection signal, and a second liquid level measuring device detects the liquid level in the secondary separator and sends a second liquid level detection signal. The controller receives the first liquid level detection signal and controls the first liquid discharge control valve to operate according to a preset value, and receives the second liquid level detection signal and controls the opening and closing of the second liquid discharge control valve according to a preset value, thus achieving timed and quantitative liquid discharge. Through the series configuration of the primary and secondary separators and the liquid level control by the controller, the problems of incomplete gas-liquid separation of phosphorus trichloride and easy liquid overflow are effectively solved.

[0032] In addition, the first differential pressure transmitter is connected to the upper and lower parts of the side wall of the first stage separator through the first pressure tapping tube to realize differential pressure measurement. The probe part of the first radar level gauge is extended and set in the first stage separator to realize level detection. The controller uses the displayed high level value as the control basis, which effectively avoids the measurement error and equipment failure risk of a single detection method. The second differential pressure transmitter and the second radar level gauge use the same dual detection principle in the second stage separator.

[0033] In summary, this invention achieves efficient separation of phosphorus trichloride gas-liquid mixtures and overflow prevention control of liquid level, significantly improving separation efficiency and reducing operational risks and maintenance costs. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the phosphorus trichloride separation equipment of this utility model. Detailed Implementation

[0035] To make the contents of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0036] like Figure 1 As shown, a phosphorus trichloride separation device includes:

[0037] The first-stage separator 1 has a tail gas inlet 11 and a first gas outlet 12 at its top and a first liquid outlet 13 at its bottom. The tail gas inlet 11 is suitable for introducing tail gas after phosphorus trichloride gas has been condensed.

[0038] The secondary separator 2 has a separation inlet 21 and an exhaust outlet 22 at its top. The separation inlet 21 is connected to the first gas outlet 12. The secondary separator 2 is adapted to receive the gas separated from the primary separator 1. The second liquid outlet 23 is provided at the bottom of the secondary separator 2.

[0039] The first liquid level measuring device is installed on the first-stage separator 1 and is used to collect the liquid level in the first-stage separator 1.

[0040] The second liquid level measuring device is installed on the secondary separator 2 and is used to collect the liquid level in the secondary separator 2.

[0041] The controller is connected to the first liquid level measuring device and the second liquid level measuring device, respectively;

[0042] The first liquid discharge control valve 3 is installed on the liquid discharge pipeline of the first liquid outlet 13 and is connected to the controller.

[0043] The second liquid discharge control valve 4 is installed on the liquid discharge pipeline of the second liquid outlet 23 and is connected to the controller.

[0044] The controller is adapted to control the operation of the first liquid discharge control valve 3 based on the liquid level collected by the first liquid level measuring device and to control the operation of the second liquid discharge control valve 4 based on the liquid level collected by the second liquid level measuring device.

[0045] In this embodiment, as Figure 1As shown, during operation, the phosphorus trichloride gas, after condensation, enters the primary separator 1 through the exhaust gas inlet 11. Gas-liquid separation occurs inside the primary separator 1. The separated liquid settles to the bottom and is discharged through the first liquid outlet 13, while the separated gas exits from the first gas outlet 12 at the top and enters the separation inlet 21 of the secondary separator 2. Inside the secondary separator 2, the gas from the primary separator 1 undergoes further separation. The remaining liquid is discharged through the second liquid outlet 23, and the non-condensable gas is discharged through the exhaust outlet 22. A first liquid level measuring device detects the liquid level in the primary separator 1 and sends a first liquid level detection signal, while a second liquid level measuring device detects the liquid level in the secondary separator 2 and sends a second liquid level detection signal. The controller receives the first liquid level detection signal and controls the first liquid discharge control valve to operate according to a preset value. It also receives the second liquid level detection signal and controls the opening and closing of the second liquid discharge control valve 4 according to a preset value, achieving timed and quantitative liquid discharge. Through the series configuration of the primary separator 1 and the secondary separator 2, and the liquid level control by the controller, the problems of incomplete gas-liquid separation and overflow of phosphorus trichloride are solved. The controller can specifically be a PLC. The first liquid discharge control valve 3 and the second liquid discharge control valve 4 can specifically be pneumatic regulating valves.

[0046] Specifically, such as Figure 1 As shown, the first liquid level measuring device includes:

[0047] The first differential pressure transmitter 31 is connected to the upper and lower parts of the side wall of the first stage separator 1 through the first pressure tapping pipe, and the first differential pressure transmitter 31 is connected to the controller.

[0048] The first radar level gauge 33 is installed on the top of the first stage separator 1. The probe part of the first radar level gauge 33 extends into the first stage separator 1 and is connected to the controller.

[0049] The controller is adapted to control the operation of the first liquid discharge control valve 3 according to the liquid level of the first differential pressure transmitter 31 or the liquid level of the first radar level gauge 33.

[0050] Specifically, such as Figure 1 As shown, the second liquid level measuring device includes:

[0051] The second differential pressure transmitter 32 is connected to the upper and lower parts of the side wall of the secondary separator 2 through the second pressure tapping pipe, and is connected to the controller.

[0052] The second radar level gauge 34 is installed on the top of the secondary separator 2. The probe part of the second radar level gauge 34 extends into the secondary separator 2 and is connected to the controller.

[0053] The controller is adapted to control the operation of the first liquid discharge control valve 3 according to the liquid level of the second differential pressure transmitter 32 or the liquid level of the second radar level gauge 34.

[0054] In this embodiment, as Figure 1 As shown, the first differential pressure transmitter 31 is connected to the upper and lower parts of the side wall of the first-stage separator 1 through the first pressure tapping pipe. It measures the pressure difference between two points inside the first-stage separator 1 and converts the pressure difference signal into an electrical signal, which is then transmitted to the controller. The probe of the first radar level gauge 33 extends downward from the top of the first-stage separator 1 into the interior. It detects the liquid level by emitting radar waves and receiving reflected signals, and transmits the liquid level information to the controller in the form of an electrical signal. The controller takes the higher liquid level value as the basis for controlling the actual liquid level of the first-stage separator 1.

[0055] The liquid level detection in the secondary separator 2 uses the same detection method. The second differential pressure transmitter 32 is connected to the upper and lower parts of the side wall of the secondary separator 2 through the second pressure tapping pipe to measure the differential pressure. The second radar level gauge 34 is installed on the top of the secondary separator 2 to detect the liquid level. The controller uses the same processing method as the primary separator 1 based on the received signal.

[0056] Specifically, such as Figure 1 As shown, the phosphorus trichloride separation equipment also includes a phosphorus trichloride storage tank (not shown in the figure). The phosphorus trichloride storage tank is provided with a first liquid inlet and a second liquid inlet. The first liquid inlet is connected to the first liquid outlet 13, and the second liquid inlet is connected to the second liquid outlet 23.

[0057] Specifically, such as Figure 1 As shown, the phosphorus trichloride separation equipment also includes a tail gas absorption tower (not shown in the figure), and the inlet end of the tail gas absorption tower is connected to the tail gas emission port 22.

[0058] In this embodiment, as Figure 1 As shown, the phosphorus trichloride storage tank has two independent inlet ports. The first inlet port is connected to the first liquid outlet 13 of the primary separator 1 via a pipeline, receiving the phosphorus trichloride liquid separated by the primary separator 1. The second inlet port is connected to the second liquid outlet 23 of the secondary separator 2 via a pipeline, receiving the phosphorus trichloride liquid separated by the secondary separator 2. When the first liquid discharge control valve 3 and the second liquid discharge control valve 4 are opened, the phosphorus trichloride liquid from the primary separator 1 enters the phosphorus trichloride storage tank through the first inlet port, and the phosphorus trichloride liquid from the secondary separator 2 enters the phosphorus trichloride storage tank through the second inlet port for unified collection and storage.

[0059] Specifically, such as Figure 1 As shown, it also includes an inlet pipeline, an outlet pipeline, and a maintenance switching system. The maintenance switching system includes:

[0060] The first feed shut-off valve 7 has one end connected to the feed pipeline and the other end connected to the exhaust gas inlet 11. The first feed shut-off valve 7 is also connected to the controller.

[0061] The second discharge control valve 9 has one end connected to the exhaust port 22 and the other end connected to the discharge pipeline. The second discharge control valve 9 is also connected to the controller.

[0062] Bypass pipe 5, one end of which has a converging end, and the other end is connected to the discharge pipe. The converging end is connected to the feed pipe through a branch pipe. A branch control valve is provided in the branch pipe, and the branch control valve is connected to the controller.

[0063] The three-way switching valve 8 has a first port, a second port and a third port. The first port is connected to the first gas outlet 12 of the first separator 1, the second port is connected to the collection end, and the third port is connected to the separation inlet 21 of the secondary separator 2. The three-way switching valve 8 is connected to the controller.

[0064] Bypass control valve 6 is connected in bypass pipeline 5 and is connected to the controller.

[0065] In this embodiment, as Figure 1 As shown, when the primary separator 1 needs maintenance, repair or malfunction, the controller controls the bypass control valve 6 to close and the branch control valve to open. At the same time, the first feed shut-off valve 7 closes, the three-way switching valve 8 switches to connect the second port and the third port and closes the first port. The intake air enters the collection end from the branch pipeline, and then enters the secondary separator 2 through the second port and the third port of the three-way switching valve 8 for separation.

[0066] When the secondary separator 2 needs maintenance, repair or malfunction, the controller controls the bypass control valve 6 to open and the branch control valve to close. At the same time, the three-way switching valve 8 switches to connect the first port and the second port and close the third port. The gas separated by the primary separator 1 enters the collection end through the first port and the second port of the three-way switching valve 8, and then enters the discharge pipeline through the bypass pipeline 5 and flows to the tail gas absorption tower.

[0067] Under normal operating conditions, the controller closes the bypass control valve 6 and the branch control valve, and the three-way switching valve 8 switches to connect the first and third ports while closing the second port. The gas then sequentially enters the primary separator 1 and the secondary separator 2 for separation according to the design flow. The bypass control valve 6 and the branch control valve can specifically be pneumatic ball valves.

[0068] The specific embodiments described above further illustrate the technical problems, technical solutions, and beneficial effects of this utility model. It should be understood that the above descriptions are merely specific embodiments of this utility model and are not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A phosphorus trichloride separation apparatus, characterized by, include: A primary separator (1) is provided with a tail gas inlet (11) and a first gas outlet (12) at the top and a first liquid outlet (13) at the bottom. The tail gas inlet (11) is suitable for introducing tail gas after phosphorus trichloride gas has been condensed. A secondary separator (2) is provided with a separation inlet (21) and an exhaust outlet (22) at the top. The separation inlet (21) is connected to the first gas outlet (12). The secondary separator (2) is adapted to receive gas separated from the primary separator (1). A second liquid outlet (23) is provided at the bottom of the secondary separator (2). A first liquid level measuring device is installed on the first-stage separator (1) and used to collect the liquid level inside the first-stage separator (1); The second liquid level measuring device is installed on the secondary separator (2) and is used to collect the liquid level in the secondary separator (2); A controller, which is connected to the first liquid level measuring device and the second liquid level measuring device respectively; The first liquid discharge control valve (3) is installed on the liquid discharge pipeline of the first liquid outlet (13) and is connected to the controller. The second liquid discharge control valve (4) is installed on the liquid discharge pipeline of the second liquid outlet (23) and is connected to the controller. The controller is adapted to control the operation of the first liquid discharge control valve (3) based on the liquid level collected by the first liquid level measuring device and to control the operation of the second liquid discharge control valve (4) based on the liquid level collected by the second liquid level measuring device.

2. The phosphorus trichloride separation equipment according to claim 1, characterized in that, The first liquid level measuring device includes: The first differential pressure transmitter (31) is connected to the upper and lower parts of the side wall of the first stage separator (1) through the first pressure tapping pipe, and the first differential pressure transmitter (31) is connected to the controller. The first radar level gauge (33) is installed on the top of the first stage separator (1), and the probe portion of the first radar level gauge (33) extends into the first stage separator (1). The first radar level gauge (33) is connected to the controller. The controller is adapted to control the operation of the first liquid discharge control valve (3) according to the liquid level of the first differential pressure transmitter (31) or the liquid level of the first radar level gauge (33).

3. The phosphorus trichloride separation equipment according to claim 1, characterized in that, The second liquid level measuring device includes: The second differential pressure transmitter (32) is connected to the upper and lower parts of the side wall of the secondary separator (2) through the second pressure tapping pipe, and the second differential pressure transmitter (32) is connected to the controller. The second radar level gauge (34) is installed on the top of the secondary separator (2), and the probe portion of the second radar level gauge (34) extends into the secondary separator (2). The second radar level gauge (34) is connected to the controller. The controller is adapted to control the operation of the second liquid discharge control valve (4) according to the liquid level of the second differential pressure transmitter (32) or the liquid level of the second radar level gauge (34).

4. The phosphorus trichloride separation equipment according to claim 1, characterized in that, It also includes a phosphorus trichloride storage tank, which is provided with a first liquid inlet and a second liquid inlet. The first liquid inlet is connected to the first liquid outlet (13), and the second liquid inlet is connected to the second liquid outlet (23).

5. The phosphorus trichloride separation equipment according to claim 1, characterized in that, It also includes an exhaust gas absorption tower, the inlet of which is connected to the exhaust gas outlet (22).

6. The phosphorus trichloride separation equipment according to claim 1, characterized in that, It also includes the feed pipeline, the discharge pipeline, and the maintenance and switching system, which includes: The first feed shut-off valve (7) has one end connected to the feed pipeline and the other end connected to the exhaust gas inlet (11). The first feed shut-off valve (7) is connected to the controller. The second discharge control valve (9) has one end connected to the exhaust port (22) and the other end connected to the discharge pipeline. The second discharge control valve (9) is connected to the controller. Bypass pipe (5), one end of the bypass pipe (5) has a converging end and the other end is connected to the discharge pipe. The converging end is connected to the feed pipe through a branch pipe. A branch control valve is provided in the branch pipe and the branch control valve is connected to the controller. Three-way switching valve (8) is provided with a first port, a second port and a third port. The first port is connected to the first gas outlet (12) of the first stage separator (1), the second port is connected to the collection end, and the third port is connected to the separation inlet (21) of the second stage separator (2). The three-way switching valve (8) is connected to the controller. A bypass control valve (6) is connected in a bypass pipeline (5) and is connected to a controller.

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