A device for adsorbing and removing arsenic impurities in phosphorus trichloride production

Abstract

The utility model discloses a kind of arsenic impurity adsorption removal devices in phosphorus trichloride production, belong to chemical purification equipment technical field, including the mixing bucket for phosphorus trichloride mixture storage, the outer periphery of the mixing bucket is connected with two discharge outlets for phosphorus trichloride mixture flow, the end portion of two the discharge outlet away from mixing bucket is connected with self-adapting sealing pipe, the vertical inner wall of the self-adapting sealing pipe is fixedly connected with support frame, the side surface of the support frame is installed with hollow column, the inside of the hollow column is connected with spring, one end of the spring is connected with moving disc, the end of moving disc away from spring is connected with connecting column, the moving disc is slidably arranged in the inside of hollow column, the device utilizes double-path design, avoids single-path adsorption device production interruption when replacing adsorption material, significantly improves the continuous operation ability of device, improves production efficiency.

Description

Technical Field

[0001] This utility model belongs to the technical field of chemical purification equipment, and in particular to an adsorption and removal device for arsenic impurities in the production of phosphorus trichloride. Background Technology

[0002] Phosphorus trichloride is an important chemical raw material widely used in pesticides, pharmaceuticals, dyes, and other industries. During the production of phosphorus trichloride, the arsenic contained in the raw material yellow phosphorus forms arsenic chloride impurities, affecting the purity and quality of the phosphorus trichloride product. Once the adsorbent (such as modified activated carbon or activated alumina) in the adsorption tank (adsorption tower) reaches saturation with AsCl3, it needs to be replaced to continue purification. If the replacement capacity is weak, production will be interrupted, reducing capacity.

[0003] A search revealed Chinese patent document (authorization announcement number CN205307842U), which discloses a phosphorus trichloride arsenic removal device. This device comprises a tower body, a pre-injection system, a multi-stage distributor, and multi-layer packing. The tower body has a feed pipe, a drain pipe, and an exhaust pipe. The feed pipe is connected to the upper part of one side of the tower body, extending from outside the tower body into the tower body. The drain pipe is connected to the lower end of the tower body, and the exhaust pipe is connected to the lower part of one side of the tower body. The pre-injection system is connected to the feed pipe extending into the tower body, and the two are connected by a flange. Below the pre-injection system inside the tower body, a multi-stage distributor and multi-layer packing are connected to the inner wall of the tower body. The multi-stage distributor and multi-layer packing have identical structures and are connected alternately to the inner wall of the tower body. This device features increased tower height, multi-layer packing, and a multi-stage distributor, resulting in more uniform material distribution, better arsenic removal effect, higher phosphorus trichloride purity, and improved product quality, meeting export requirements. While the device meets basic usage needs, its weak replacement capability leads to production interruptions and reduced capacity. Utility Model Content

[0004] The purpose of this invention is to provide an adsorption and removal device for arsenic impurities in phosphorus trichloride production, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: an arsenic impurity adsorption and removal device in the production of phosphorus trichloride, comprising a mixing tank for storing a phosphorus trichloride mixture, wherein the outer periphery of the mixing tank is connected to two discharge ports for the flow of the phosphorus trichloride mixture; Both discharge ports are connected to adaptive sealing tubes at their ends away from the mixing tank. A support frame is fixedly connected to the vertical inner wall of the adaptive sealing tube. A hollow column is installed on the side of the support frame. A spring is connected inside the hollow column. One end of the spring is connected to a movable disk. A connecting column is connected to the end of the movable disk away from the spring. The movable disk is slidably disposed inside the hollow column. A conical sealing block for adjusting the flow rate of phosphorus trichloride liquid is installed at the end of the connecting column away from the movable disk.

[0006] Preferably, the vertical inner wall of the adaptive sealing tube is equipped with a sealing ring for engaging with the top of the conical sealing block, and the end of the adaptive sealing tube away from the outlet is equipped with a conical inlet hopper for engaging with the conical sealing block.

[0007] Preferably, a connecting pipe is slidably provided on the outer periphery of the adaptive sealing tube, and the end of the connecting pipe is provided with a hole for locking with the discharge port.

[0008] Preferably, a connecting frame is fixedly installed on the vertical inner wall of the connecting pipe, and a stop post for contacting the bottom of the conical sealing block is installed on the top of the connecting frame.

[0009] Preferably, the end of the connecting pipe is connected to an adsorption and removal tank, and the vertical inner wall of the adsorption and removal tank is provided with a groove for restricting the direction of movement, and an adsorption frame for support is slidably installed inside the groove.

[0010] Preferably, the adsorption rack is equipped with multiple adsorption plates for removing arsenic impurities during phosphorus trichloride production, and the end of the adsorption and removal tank away from the connecting pipe is connected to a discharge pipe for discharging phosphorus trichloride.

[0011] Preferably, one end of the mixing tank is equipped with a feed port for connecting and fixing an external phosphorus trichloride mixture pipe, the other end of the mixing tank is equipped with an observation mirror for observing the inside of the mixing tank, and a filter screen is installed inside the mixing tank.

[0012] Compared with the prior art, the technical effects and advantages of this utility model are as follows: The arsenic impurity adsorption and removal device in phosphorus trichloride production benefits from the structure of the adsorption and removal tanks. When the adsorption plates in one set of adsorption and removal tanks reach saturation, the corresponding connecting pipe can be separated, and the passage can be closed using the automatic sealing function of the adaptive sealing pipe. At the same time, the other set of adsorption and removal tanks can be started to continue working. This dual-path design avoids production interruptions when changing adsorption materials in a single-path adsorption device, significantly improving the continuous operation capability of the device and increasing production efficiency.

[0013] The arsenic impurity adsorption and removal device in the production of phosphorus trichloride benefits from the structure of the conical sealing block and the conical inlet hopper. In the initial state, the conical sealing block and the conical inlet hopper fit tightly together to ensure that the mixture will not leak. When the connecting pipe is connected, the abutment pushes the conical sealing block to compress the spring, automatically opening the passage. No additional manual switch control is required, which not only ensures the reliability of the seal, but also simplifies the operation process and improves the sealing performance and convenience of the device. Attached Figure Description

[0014] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a cross-sectional view of the present invention; Figure 3 This is a schematic diagram of the internal structure of this utility model; Figure 4 This utility model Figure 2 Enlarged view of point A in the middle; Figure 5 This utility model Figure 3 Enlarged view of point B in the middle.

[0016] Explanation of reference numerals in the attached figures: In the diagram: 1. Mixing tank; 101. Feed inlet; 102. Observation mirror; 103. Discharge port; 104. Filter screen; 2. Adaptive sealing tube; 201. Support frame; 202. Hollow column; 203. Spring; 204. Moving disc; 205. Connecting column; 206. Conical sealing block; 207. Sealing ring; 208. Conical liquid inlet hopper; 3. Connecting pipe; 301. Connecting frame; 302. Support column; 4. Adsorption and desorption tank; 401. Slide groove; 402. Adsorption frame; 403. Adsorption disc; 404. Discharge pipe. Detailed Implementation

[0017] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with the present invention.

[0018] The connection method can be any existing method, such as bonding, welding, or bolting, depending on the actual needs.

[0019] like Figures 1 to 5 The device shown is an arsenic impurity adsorption and removal device in the production of phosphorus trichloride, including a mixing tank 1 for storing a phosphorus trichloride mixture, and two discharge ports 103 for the flow of the phosphorus trichloride mixture connected to the outer periphery of the mixing tank 1. Both discharge ports 103 are connected to adaptive sealing pipes 2 at their ends away from the mixing tank 1. A support frame 201 is fixedly connected to the vertical inner wall of the adaptive sealing pipe 2. A hollow column 202 is installed on the side of the support frame 201. A spring 203 is connected inside the hollow column 202. A movable disk 204 is connected to one end of the spring 203. A connecting column 205 is connected to the end of the movable disk 204 away from the spring 203. The movable disk 204 is slidably disposed inside the hollow column 202. A conical sealing block 206 for adjusting the flow rate of phosphorus trichloride liquid is installed at the end of the connecting column 205 away from the movable disk 204. The pretreated mixture is temporarily stored in the mixing tank 1 and communicates with the adaptive sealing pipe 2 through the two discharge ports 103. In the initial state, the spring 203 inside the adaptive sealing tube 2 is in a naturally extended state, pushing the moving disk 204 (sliding inside the hollow column 202) and the connecting column 205, so that the conical sealing block 206 fits tightly against the inner wall of the conical liquid inlet 208, thereby achieving pipeline sealing (blocking the flow of the mixed liquid to the connecting tube 3).

[0020] The adaptive sealing tube 2 has a sealing ring 207 installed on its vertical inner wall to mate with the top of the conical sealing block 206. A conical inlet hopper 208 is installed at the end of the adaptive sealing tube 2 away from the outlet 103 to mate with the conical sealing block 206. When the adsorption-removal process needs to be started, the connecting tube 3 is slidably connected to the adaptive sealing tube 2, and the hole at the end of the connecting tube 3 engages and locks with the outlet 103. At this time, the abutment 302 on the connecting frame 301 inside the connecting tube 3 pushes the conical sealing block 206 upward, compressing the spring 203 and separating the conical sealing block 206 from the inner wall of the conical inlet hopper 208, forming a flow channel. The mixed liquid enters the connecting tube 3 through the conical inlet hopper 208, opening the passage from the mixing tank 1 to the adsorption-removal tank 4.

[0021] A connecting pipe 3 is slidably mounted on the outer periphery of the adaptive sealing pipe 2. The end of the connecting pipe 3 is fitted with a hole for locking with the outlet 103. A connecting frame 301 is fixedly mounted on the vertical inner wall of the connecting pipe 3. A stop post 302 is mounted on the top of the connecting frame 301 for contacting the bottom of the conical sealing block 206. When the adsorbent in a certain adsorption / desorption tank 4 reaches saturation, the corresponding connecting pipe 3 and the adaptive sealing pipe 2 slide apart. At this time, the spring 203 resets, pushing the conical sealing block 206 to tightly adhere to the inner wall of the conical inlet hopper 208 again, achieving automatic sealing of the passage. Simultaneously, another combination of the outlet 103, the adaptive sealing pipe 2, and the adsorption / desorption tank 4 can be activated to ensure continuous operation of the device and avoid production interruptions.

[0022] The end of the connecting pipe 3 is connected to the adsorption and removal tank 4. The vertical inner wall of the adsorption and removal tank 4 is provided with a chute 401 for limiting the direction of movement. An adsorption frame 402 for support is slidably installed inside the chute 401. Multiple adsorption plates 403 for removing arsenic impurities in the production of phosphorus trichloride are installed inside the adsorption frame 402. The end of the adsorption and removal tank 4 away from the connecting pipe 3 is connected to a discharge pipe 404 for discharging phosphorus trichloride. After the mixed liquid enters the adsorption and removal tank 4 through the connecting pipe 3, it flows along the adsorption frame 402 limited by the chute 401 and passes through multiple adsorption plates 403 in the adsorption frame 402 in sequence. The adsorbent (such as modified activated carbon, activated alumina, etc.) in the adsorption plate 403 selectively adsorbs arsenic impurities (mainly arsenic trichloride) in the mixed liquid, completing the purification process. The high-purity phosphorus trichloride with arsenic impurities removed is discharged through the discharge pipe 404 at the end of the adsorption removal tank 4 and enters the subsequent production stage. The top of the adsorption removal tank 4 is equipped with a tail gas interface, which is connected to the alkaline absorption tower to treat the volatile gases. The side is equipped with a quick-opening maintenance door, and the adsorption rack 402 can be pulled out through the slide 401 for easy replacement of the adsorption plate 403.

[0023] One end of the mixing tank 1 is equipped with a feed inlet 101 for connecting and fixing an external phosphorus trichloride mixture pipe. The other end of the mixing tank 1 is equipped with an observation mirror 102 for observing the interior of the mixing tank 1. A filter screen 104 is installed inside the mixing tank 1. The phosphorus trichloride mixture containing arsenic impurities enters the device through the feed inlet 101, first passing through the filter screen 104 inside the mixing tank 1 to filter out solid particulate impurities. The operator can observe the liquid level and state of the mixture inside the mixing tank 1 through the observation mirror 102.

[0024] Regarding the maintenance, sealing, and working environment of the arsenic impurity adsorption and removal device in phosphorus trichloride production, it is necessary to address these issues before using the equipment. For example, the waste adsorbent generated after the adsorption plate 403 becomes saturated needs to be sealed and collected, and handed over to a professional institution for harmless treatment (such as high-temperature solidification or chemical stabilization) to prevent arsenic leakage and pollution of soil and water bodies. Trace amounts of volatile gases (such as PCl3 and AsCl3) generated during the operation of the device need to be connected to a waste gas treatment device (such as an alkaline absorption tower) through the tail gas interface at the top of the adsorption and removal tank 4 to prevent toxic gases from being emitted into the atmosphere. The contact surface between the conical sealing block 206 and the conical liquid inlet hopper 208 is made of corrosion-resistant fluororubber, forming a double seal with the sealing ring 207 (made of polytetrafluoroethylene). An O-ring is installed at the joint between the connecting pipe 3 and the adaptive sealing pipe 2, and an elastic locking pin is set in the locking hole to ensure no liquid leakage after the joint. The device needs to be inspected weekly. Inspect the filter screen 104 with microscope 102 to check for blockage. If impurities accumulate, disassemble and clean it promptly. Lubricate the spring 203 and moving disc 204 in the adaptive sealing tube 2 monthly (using chlorine-resistant silicone-based grease) to prevent jamming and affect sealing performance. Replace the adsorption disc 403 every 3 months. Before replacement, purge the adsorption and removal tank 4 with nitrogen to prevent residual PCl3 from oxidizing upon contact with air. The mixing tank 1, adaptive sealing tube 2, connecting tube 3, and adsorption and removal tank 4 are all made of 316L stainless steel, which is resistant to corrosion from PCl3 and AsCl3. The filter screen 104 is made of Hastelloy alloy with a pore size of 50μm, balancing filtration efficiency and corrosion resistance. Suitable operating temperature (recommended to be controlled between 20-40℃ to avoid high temperature causing increased volatilization of phosphorus trichloride) and pressure range (the system should be kept under a slight positive pressure of 0.02-0.05MPa to prevent air from entering and causing oxidation).

[0025] Temperature sensors and pressure gauges can be installed on the mixing tank 1 and the adsorption-removal tank 4 to monitor the operating status in real time and ensure efficient arsenic removal under optimal parameters. An online arsenic content detector is installed at the discharge pipe 404 of the adsorption-removal tank 4. When the arsenic content in phosphorus trichloride exceeds the set threshold (e.g., 0.5 ppm), an audible and visual alarm is automatically triggered, reminding operators to check the adsorption effect of the adsorption plate 403 or replace the adsorbent. Simultaneously, overpressure protection valves are installed on the mixing tank 1 and all connecting pipes. When the system pressure exceeds 0.1 MPa, the valves automatically release pressure to prevent equipment damage due to overpressure. A dedicated emergency leak handling kit is provided, containing adsorption cotton, neutralizing agents (e.g., lime powder), etc., for rapid containment, adsorption, and neutralization in the event of phosphorus trichloride or arsenic compound leaks. A dike and emergency collection pool are set up around the device to prevent leaked materials from spreading to the external environment. Detailed emergency operating procedures are developed, and operators are regularly trained and drilled to ensure timely and effective handling in emergencies. During transportation, the device must be securely fixed to avoid damage to components due to severe vibration. Special lifting equipment should be used during loading and unloading, and impacts to critical components such as the adsorption and removal tank 4 and mixing tank 1 are strictly prohibited. During storage, the device should be placed in a dry, well-ventilated indoor environment, away from fire, heat sources, and corrosive substances. Before long-term storage, the system should be purged with nitrogen to remove residual phosphorus trichloride and arsenic compounds, and all sealing components should be wiped clean and coated with protective grease to prevent rust. When the device reaches the end of its service life or cannot be repaired, it must be scrapped. Components that have come into contact with arsenic compounds (such as adsorption plate 403, adsorption rack 402, conical sealing block 206, etc.) should be collected separately as hazardous waste and handed over to a qualified unit for professional disposal; they must not be discarded arbitrarily. Metal components (such as mixing tank 1, connecting pipe 3, etc.) must undergo thorough decontamination treatment, and only after the arsenic content is tested and found to be within the standard range can they be recycled or disposed of.

[0026] Working principle In this arsenic impurity adsorption and removal device for phosphorus trichloride production, the phosphorus trichloride mixture containing arsenic impurities first enters through the feed port 101 of the mixing tank 1, and solid particles are filtered out by the internal filter screen 104. The operator can observe the internal state through the observation window 102. After the mixture is temporarily stored in the mixing tank 1, it is diverted to the corresponding adaptive sealing pipe 2 through two discharge ports 103. In the initial state, the spring 203 inside the adaptive sealing tube 2 extends naturally, pushing the moving disk 204 to slide inside the hollow column 202. This causes the connecting column 205 to tightly fit the conical sealing block 206 against the inner wall of the conical inlet hopper 208, achieving pipeline sealing and blocking the flow of the mixed liquid. When adsorption needs to be started, the connecting tube 3 is slidably connected to the adaptive sealing tube 2, locking its end hole with the outlet 103. Simultaneously, the abutment column 302 on the connecting frame 301 pushes the conical sealing block 206 upward, compressing the spring 203 to separate it from the conical inlet hopper 208, forming a passage. The mixed liquid enters the connecting tube 3 through the conical inlet hopper 208. After entering the adsorption removal tank 4, the mixed liquid flows along the adsorption frame 402 limited by the chute 401, passing through multiple adsorption disks 403 in sequence, utilizing the adsorbent to selectively adsorb arsenic impurities. The purified phosphorus trichloride is discharged through the outlet pipe 404. If a certain adsorption tank becomes saturated, the corresponding connecting pipe 3 is disconnected, the spring 203 resets, and the conical sealing block 206 seals the pipeline, switching to another set of adsorption tanks to continue working and ensure continuous production.

[0027] It should be noted that in this article, relational terms such as one and two are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0028] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An adsorption and removal device for arsenic impurities in phosphorus trichloride production, comprising a mixing tank (1) for storing phosphorus trichloride mixtures, characterized in that: The outer periphery of the mixing tank (1) is connected to two outlets (103) for the flow of phosphorus trichloride mixture. Both discharge ports (103) are connected to an adaptive sealing tube (2) at the ends away from the mixing tank (1). A support frame (201) is fixedly connected to the vertical inner wall of the adaptive sealing tube (2). A hollow column (202) is installed on the side of the support frame (201). A spring (203) is connected inside the hollow column (202). A movable disk (204) is connected to one end of the spring (203). A connecting column (205) is connected to the end of the movable disk (204) away from the spring (203). The movable disk (204) is slidably disposed inside the hollow column (202). A conical sealing block (206) for adjusting the flow rate of phosphorus trichloride liquid is installed at the end of the connecting column (205) away from the movable disk (204).

2. The arsenic impurity adsorption and removal device in phosphorus trichloride production according to claim 1, characterized in that: The adaptive sealing tube (2) has a sealing ring (207) installed on its vertical inner wall for cooperating with the top of the conical sealing block (206), and a conical liquid inlet hopper (208) for cooperating with the conical sealing block (206) is installed at the end of the adaptive sealing tube (2) away from the outlet (103).

3. The arsenic impurity adsorption and removal device in phosphorus trichloride production according to claim 1, characterized in that: The outer periphery of the adaptive sealing tube (2) is slidably provided with a connecting tube (3), and the end of the connecting tube (3) is provided with a hole for locking with the discharge port (103).

4. The arsenic impurity adsorption and removal device in phosphorus trichloride production according to claim 3, characterized in that: A connecting frame (301) is fixedly installed on the vertical inner wall of the connecting pipe (3), and a stop (302) for contacting the bottom of the conical sealing block (206) is installed on the top of the connecting frame (301).

5. The arsenic impurity adsorption and removal device in phosphorus trichloride production according to claim 3, characterized in that: The end of the connecting pipe (3) is connected to an adsorption removal tank (4). The vertical inner wall of the adsorption removal tank (4) is provided with a groove (401) for limiting the direction of movement. An adsorption frame (402) for support is slidably installed inside the groove (401).

6. The arsenic impurity adsorption and removal device in phosphorus trichloride production according to claim 5, characterized in that: The adsorption rack (402) is equipped with multiple adsorption plates (403) for removing arsenic impurities in the production of phosphorus trichloride. The adsorption removal tank (4) is connected to a discharge pipe (404) for discharging phosphorus trichloride at the end away from the connecting pipe (3).

7. The arsenic impurity adsorption and removal device in phosphorus trichloride production according to claim 1, characterized in that: One end of the mixing tank (1) is equipped with a feed port (101) for connecting and fixing an external phosphorus trichloride mixture pipe, and the other end of the mixing tank (1) is equipped with an observation mirror (102) for observing the inside of the mixing tank (1). A filter screen (104) is installed inside the mixing tank (1).

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