An accident chlorine absorption treatment device for trichloroethylene production

Abstract

The application relates to the technical field of environmental protection equipment, and discloses an accident chlorine absorption treatment device for trichloroethylene production, which comprises an absorption assembly and an absorption tower. Three to five absorption cylinders are arranged in the absorption tower. The absorption cylinder comprises a filler cylinder, an alkali liquid cylinder for containing alkali liquid and a liquid spraying assembly. The alkali liquid cylinder is movably arranged below the filler cylinder and is provided with a driving piece. The driving piece is configured to drive the alkali liquid cylinder to vertically ascend and descend. The accident chlorine absorption treatment device for trichloroethylene production can periodically wash and moisten the filler through the liftable alkali liquid cylinder, so that the filler can be kept in a moistened state at any time to eliminate the "capacity blank period", and the crystallization blockage and equipment corrosion caused by long-term storage of the alkali liquid can be avoided.

Description

Technical Field

[0001] This application relates to the field of environmental protection equipment technology, and in particular to an emergency chlorine absorption and treatment device for trichloroethylene production. Background Technology

[0002] Trichloroethylene, an important organic solvent and chemical intermediate, is mainly produced in my country using the acetylene process. This process uses acetylene as a raw material, which reacts with chlorine at 90–130°C in a liquid phase to produce tetrachloroethane, which is then saponified and dechlorinated to obtain trichloroethylene. Throughout the production process, chlorine is used in large quantities as a key raw material, and any leak will pose a serious threat to personnel safety, equipment and facilities, and the surrounding environment.

[0003] To address the risk of chlorine leaks, chemical companies generally equip themselves with emergency chlorine absorption devices as the last line of defense. These devices mainly consist of an emergency fan, an alkali circulation pump, an absorption tower (usually a packed tower), an alkali circulation tank, and an alkali cooler. Their working principle is to use sodium hydroxide solution to neutralize chlorine gas, thereby converting toxic chlorine gas into harmless salts.

[0004] Because the equipment needs to be kept in an "always-on" emergency state, but is actually idle for long periods of time during operation, the packing surface remains dry. The main reason for this problem is that if the absorption tower is filled with alkali solution for a long time to keep the packing moist, the alkali solution will absorb carbon dioxide from the air to form sodium carbonate crystals, which will block the pores of the packing and the spray system, and at the same time aggravate equipment corrosion. On the other hand, adopting solutions such as periodic test circulation (running for 5-10 minutes per month) or constant flow in the high-level tank will, on the one hand, corrode the alkali solution circulation equipment due to long-term operation, and on the other hand, the wetting effect is short-lived, resulting in serious waste of resources and still failing to avoid the risk of crystallization.

[0005] The aforementioned technical defect in the packing material's inability to remain moist directly leads to serious safety and environmental consequences: In the event of a sudden chlorine leak (especially a large-scale leak), the unit requires a 1-3 minute rewetting process for the packing material. During this period, the gas-liquid contact area is less than 30% of the design value, resulting in a severe shortage of the unit's processing capacity. A large amount of untreated chlorine is directly emitted, with emission concentrations significantly exceeding standards. This "capacity gap" can exacerbate sudden large-scale chlorine leaks (such as pipeline ruptures or storage tank ruptures), potentially triggering secondary disasters. Summary of the Invention

[0006] This application proposes an emergency chlorine absorption and treatment device for trichloroethylene production. The packing material is periodically washed and moistened by a liftable alkali tank, which keeps the packing material in a moist state that is always available to eliminate the "capacity gap" and avoids crystallization blockage and equipment corrosion caused by long-term storage of alkali.

[0007] To achieve the above objectives, this application adopts the following technical solution: an emergency chlorine absorption and treatment device for trichloroethylene production, comprising an absorption assembly and an absorption tower. The absorption tower is provided with three to five sets of absorption cylinders. Each absorption cylinder includes a packing cylinder, an alkali cylinder for holding alkali solution, and a spraying assembly. The alkali cylinder is movably disposed below the packing cylinder and is equipped with a driving component. The driving component is configured to drive the alkali cylinder to rise and fall vertically, so that when the alkali cylinder rises to its highest position, it covers the packing cylinder from bottom to top, immersing the packing in the alkali solution. When it falls to its lowest position, the alkali solution leaks out of the packing cylinder. A controller periodically controls the driving component to raise and lower the alkali cylinder, washing the packing to maintain its wet state. A discharge valve is provided at the bottom of the alkali cylinder. The spraying assembly sprays alkali solution onto the packing cylinder.

[0008] The absorption assembly absorbs toxic gases and sends them into the absorption tower. It includes a toxic gas early warning unit. When the toxic gas early warning unit is activated, it triggers the discharge valve to open and discharge alkaline solution.

[0009] Furthermore, the bottom of the inner wall of the alkali solution cylinder is arc-shaped. This is used to collect precipitated crystals and prevent crystallization from contaminating the packing material.

[0010] Furthermore, the spraying assembly includes a spray pipe, which is fixedly connected to the bottom of the alkali cylinder. The spray pipe is connected to a connecting pipe outside the absorption tower via a flexible hose. When the toxic gas warning unit is activated, it triggers all the alkali cylinders to rise to their highest point. The lifting and lowering of the alkali cylinders occupies spraying space, making the structure compact and preventing the absorption tower from becoming too large.

[0011] Furthermore, the driving component includes telescopic cylinders and a driving pump. The alkali cylinder is connected to the packing cylinder via three telescopic cylinders. The telescopic cylinders on the same alkali cylinder form a group, and any two groups of telescopic cylinders can be connected via the driving pump. When the driving pump is working, it drives one group of telescopic cylinders to retract, while the other group descends. The hydraulic oil pressure in each group of telescopic cylinders is similar, reducing the energy consumption of each lifting and lowering of the alkali cylinder.

[0012] Furthermore, the drive pump has a hydraulic oil tank, allowing it to draw hydraulic oil from or replenish hydraulic oil to any set of alkali cylinders. The positions of each alkali cylinder are adjusted synchronously.

[0013] Furthermore, the telescopic cylinder is connected to a three-way valve, with its two ends connected to the suction port and discharge port of the drive pump, respectively.

[0014] Furthermore, a position sensor is installed inside the telescopic cylinder to monitor the position of the alkali solution cylinder.

[0015] Furthermore, the telescopic cylinder contracts when hydraulic oil is injected and extends when hydraulic oil is discharged, and the cylinder body is embedded in the alkali solution cylinder, making the structure compact.

[0016] Furthermore, the alkali solution cylinder has a closed bottom and sidewalls, and the bottom of the packing cylinder has a hollow structure while the sidewalls are closed. This allows the alkali solution to pass through the bottom of the packing cylinder while preventing gas from short-circuiting through the sidewalls.

[0017] The beneficial effects of this invention are as follows:

[0018] 1. By periodically raising and lowering the alkali tank, dynamic washing and continuous wetting of the packing are achieved, keeping the packing in an effective wet state at all times. When a sudden chlorine gas leak occurs, the device does not need to go through a packing rewetting process of one minute, and the processing capacity instantly reaches the design standard. This completely eliminates the "capacity gap period" caused by packing drying in the existing technology, and effectively avoids the safety and environmental risks of direct emission of a large amount of untreated chlorine gas.

[0019] 2. The alkali solution cylinder forms a liquid seal structure. Except for the topmost alkali solution cylinder, the alkali solution in the other alkali solution cylinders is isolated from the air, which significantly reduces carbon dioxide absorption and avoids sodium carbonate crystal formation. At the same time, the bottom of the inner wall of the alkali solution cylinder is designed to be arc-shaped, so that the crystal precipitation is concentrated at the bottom, reducing the impact of alkali solution crystallization on the packing.

[0020] 3. The hydraulic drive system is adopted, which takes advantage of the similar weight of each alkali cylinder. The hydraulic oil is transferred between different telescopic cylinders by the drive pump to achieve lifting and lowering. The overall pressure difference is small and the energy consumption is small. At the same time, there is no need to run the alkali circulation equipment for a long time, thus avoiding equipment corrosion and energy waste.

[0021] 4. Each alkali solution cylinder forms a liquid seal. Except for the topmost alkali solution cylinder, the alkali solution in the other alkali solution cylinders is sealed, absorbing less carbon dioxide from the air and making it less likely to form a large amount of crystals.

[0022] 5. During the lifting and lowering of the alkali tank, the relevant drive equipment does not come into direct contact with the alkali, effectively avoiding corrosion of the equipment by the alkali. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort:

[0024] Figure 1 This is a schematic diagram of the absorption tower in this invention;

[0025] Figure 2 This is a front view of the absorption tower in this invention;

[0026] Figure 3 This is a schematic diagram of the absorption cylinder in this invention;

[0027] Figure 4 This is a front view of the alkali solution cylinder in this invention;

[0028] Figure 5 This is a bottom view of the alkali solution cylinder in this invention;

[0029] Figure 6 This is a schematic diagram of the support cylinder and the packing cylinder in this invention;

[0030] Figure 7 This is a schematic diagram of the telescopic cylinder in this invention;

[0031] Figure 8 This is a schematic diagram of the present invention.

[0032] In the diagram: 1. Absorption assembly; 2. Absorption tower; 210. Absorption cylinder; 211. Support cylinder; 212. Packing cylinder; 213. Movable tank; 214. Alkali tank; 215. Discharge valve; 216. Observation port; 220. Exhaust duct; 230. Air inlet duct; 240. Overflow cylinder; 250. Drive component; 251. Three-way valve; 252. Telescopic cylinder; 253. Drive pump; 260. Air inlet; 270. Spray assembly; 271. Spray pipe; 272. Hose; 273. Connecting pipe; 3. Chimney; 4. Alkali tank; 5. Heat exchanger; 6. Circulating alkali pump; 7. Waste liquid tank; 8. Fan; 9. Cooling water tank. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1, please refer to Figure 8The absorption tower 2 is equipped with a circulation loop, which includes a heat exchanger 5 and a circulating alkali pump 6. The circulating alkali pump 6 provides kinetic energy for the flow of alkali solution. The inlet of the inner tube of the heat exchanger 5 is connected to the bottom overflow port of the absorption tower 2 through the circulating alkali pump 6. The outlet of the inner tube of the heat exchanger 5 is connected to the spray assembly 270 of the absorption tower 2. The spray assembly 270 of the absorption tower 2 is also connected to the alkali solution tank 4. The outer tube of the heat exchanger 5 is connected to the cooling water tank 9. The cooling water tank 9 allows cooling water to flow in the outer tube of the heat exchanger 5 to adjust the temperature of the alkali solution in the inner tube. The overflow port of the absorption tower 2 is also connected to the waste liquid tank 7. When the warning unit is activated, the alkali solution tank 4 is triggered to open and provide initial alkali solution to the spray assembly 270. At the same time, the absorption unit of the absorption assembly 1, the fan 8, and the circulating alkali pump 6 are also triggered to start. After the number of alkali solution cycles in the circulation loop reaches the set number, some or all of the alkali solution flows into the waste liquid tank 7 for storage. At the same time, the alkali solution tank 4 is replenished with new alkali solution to the circulation loop.

[0035] Please see Figures 1-7The absorption tower 2 is provided with an exhaust duct 220, an absorption cylinder 210, and an air inlet duct 230 from top to bottom. The exhaust duct 220 is connected to the chimney 3 or the next-stage absorption tower 2. The air inlet duct 230 is provided with an air inlet 260 and an overflow cylinder 240. The air inlet 260 is connected to the absorption assembly 1. The overflow cylinder 240 is provided with an overflow port. The absorption cylinder 210 is provided with three to five sets. The absorption cylinder 210 includes a support cylinder 211. The support cylinder 211 is part of the outer wall of the absorption tower 2 or is fixedly connected to the outer wall of the absorption tower 2. The inner wall of the support cylinder 211 is connected by a connecting ring. A packing cylinder 212 is fixedly connected to the support cylinder 211. The outer wall of the packing cylinder 212 and the inner wall of the support cylinder 211 form a movable groove 213. An alkali solution cylinder 214 is movably connected to the packing cylinder 212 through the movable groove 213. The alkali solution cylinder 214 has a bottom for storing alkali solution. The bottom of the packing cylinder 212 is open to store packing material, but the alkali solution can pass through. The side walls of the packing cylinder 212 remain closed to prevent gas from passing through the packing material and causing short-circuiting of the gas flow. The alkali solution cylinder 214 can rise and fall. When the alkali solution cylinder 214 rises to its highest point, the packing cylinder 212 is inserted into the alkali solution cylinder. In section 214, the packing material inside the packing cylinder 212 is immersed in alkaline solution. When the alkaline solution cylinder 214 descends to its lowest point, the packing cylinder 212 detaches from the alkaline solution cylinder 214, and the alkaline solution flows down from the packing cylinder 212. This process of immersing and detaching the packing material from the alkaline solution keeps the packing material moist and also washes it, removing residual crystals from the packing material's pores. Since the lowest point of the alkaline solution cylinder 214 is lower than the packing material, most of the crystal precipitation is concentrated at the bottom of the alkaline solution cylinder 214, reducing the probability of contaminating the packing material. A drain valve 215 is installed at the bottom of the alkaline solution cylinder 214. When the toxic gas warning unit is activated, the discharge valve 215 will also open simultaneously, releasing the alkaline solution inside, thus creating a passage within the absorption tower 2. When the gas passes through the absorption tower 2, chlorine is absorbed. The discharge valve 215 is large enough to discharge the alkaline solution within a few seconds, which increases the discharge speed of the alkaline solution and prevents the discharge valve 215 from being corroded and failing. The alkaline solution cylinder 214 is connected to a drive component 250, which drives the alkaline solution cylinder 214 to move vertically. The drive component 250 can be a cylinder or a motor, which directly drives the alkaline solution cylinder 214 to rise and fall.

[0036] The bottom of the inner wall of the alkali solution cylinder 214 is designed in an arc shape to collect precipitated crystals and prevent crystals from contaminating the packing material.

[0037] The spray assembly 270 includes a spray pipe 271, which is fixedly connected to the bottom of the alkali cylinder 214. The spray pipe 271 is connected to the external connecting pipe 273 of the absorption tower 2 via a hose 272. When the toxic gas warning unit is activated, all the alkali cylinders 214 are triggered to rise to the highest point. The spray pipe 271 rises and falls synchronously with the alkali cylinders 214. When the alkali cylinders 214 fall, they occupy the spraying space of the spray assembly 270. When the alkali cylinders 214 rise to the highest point, the spraying space of the spray assembly 270 is restored. The rise and fall of the alkali cylinders 214 does not require additional space, making the structure compact and avoiding the absorption tower 2 from becoming too large.

[0038] The upper part of the stuffing box 212 is provided with an observation port 216, which can be opened to observe the status of the packing in the stuffing box 212 or to replace the packing.

[0039] In Example 2, unlike Example 1, the alkali cylinder 214 contains alkali solution, and its repeated raising and lowering leads to energy waste and is not energy-efficient. Therefore, Example 2 improves upon Example 1 by modifying the drive component 250. The drive component 250 includes a telescopic cylinder 252 and a drive pump 253. The alkali cylinder 214 is connected to the support cylinder 211 via three telescopic cylinders 252. The telescopic cylinders 252 on the same alkali cylinder 214 form a group, and any two groups of telescopic cylinders 252 can be connected via the drive pump 253. That is, one group of telescopic cylinders 252 is connected to the suction port of the drive pump 253, and the other... The telescopic cylinder 252 is connected to the outlet of the drive pump 253. Since the alkali cylinder 214 is supported by the telescopic cylinder 252 and the weight of each alkali cylinder 214 is similar, the hydraulic oil pressure in each telescopic cylinder 252 is similar. Therefore, the energy consumption of the drive pump 253 when driving the hydraulic oil flow is small, that is, the energy consumption of each lifting and lowering of the alkali cylinder 214 is small. The drive pump 253 has a hydraulic oil tank, and the drive pump 253 can still draw hydraulic oil from any group of alkali cylinders 214 or replenish hydraulic oil to any group of alkali cylinders 214. In order to make the space more compact, the cylinder body of the telescopic cylinder 252 is embedded in the alkali cylinder 214.

[0040] The telescopic cylinder 252 is connected to a three-way valve 251. The two ends of the three-way valve 251 are connected to the suction port and discharge port of the drive pump 253, respectively. The same side of each three-way valve 251 is connected to the drive pump 253 through the same connecting pipe. When the telescopic cylinder 252 needs to add hydraulic oil (the alkali cylinder 214 rises), the telescopic cylinder 252 is connected to the discharge port of the drive pump 253. Conversely, it is connected to the suction port of the drive pump 253. The telescopic cylinder 252 is equipped with a position sensor to monitor the position of the alkali cylinder 214.

[0041] During routine maintenance, close all discharge valves 215, connect the spray assembly 270 to the alkali tank 4, and spray alkali. Observe through the observation port 216. When the alkali in each packing cylinder 212 has submerged the packing, close the alkali tank 4, connect the outlet of the drive pump 253 to the hydraulic oil tank, connect one telescopic cylinder 252 to the outlet of the drive pump 253, and connect the other telescopic cylinders 252 to the inlet of the drive pump 253. Drain the hydraulic oil from these telescopic cylinders 252, adjust the corresponding alkali cylinder 214 to the lowest point, and stop when the sensor detects that the corresponding telescopic cylinder 252 has moved to the correct position. At this time, the packing on one set of absorption cylinders 210 is soaked in alkali, while the others are not soaked. When the set time is reached, the telescopic cylinder 252 corresponding to that absorption cylinder 210 is connected to the inlet of the drive pump 253, and the next set of absorption cylinders 210... The telescopic cylinder 252 is connected to the outlet of the drive pump 253. When the telescopic cylinder 252 of the previous group extends, the alkali cylinder 214 descends to the lowest point. When the telescopic cylinder 252 of the next group retracts, the alkali cylinder 214 rises to the highest point. According to the predetermined sequence, the height of the alkali cylinder 214 corresponding to each group of absorption cylinders 210 is adjusted in turn to keep the packing in a wet or soaked state. When the toxic gas warning unit is triggered, all the discharge valves 215 are opened, and each group of absorption cylinders 210 discharges alkali, making the absorption tower 2 connected from top to bottom. The drive pump 253 injects hydraulic oil into the telescopic cylinder 252 corresponding to the alkali cylinder 214 located at the lower position, so that the alkali cylinder 214 is at the highest position, thereby positioning the spraying assembly 270. At the same time, the absorption assembly 1 opens to send gas into the absorption tower 2, and opens to send alkali into the absorption tower 2. The circulating alkali pump 6 is turned on to start the circulation of alkali.

[0042] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An emergency chlorine absorption and treatment device for trichloroethylene production, comprising a controller, an absorption assembly (1), and an absorption tower (2), characterized in that, The absorption tower (2) is equipped with three to five sets of absorption cylinders (210). Each absorption cylinder (210) includes a packing cylinder (212), an alkali cylinder (214) for holding alkali solution, and a spray assembly (270). The alkali cylinder (214) is movably disposed below the packing cylinder (212) and is equipped with a drive unit (250). The drive unit (250) is configured to drive the alkali cylinder (214) to move vertically up and down, so that the alkali cylinder (214) can move vertically up and down. 14) When it rises to the highest position, it covers the packing cylinder (212) from bottom to top, so that the packing is immersed in the alkali solution. When it descends to the lowest position, the alkali solution leaks out from the packing cylinder (212). The controller controls the drive unit (250) to raise and lower the alkali solution cylinder (214) at regular intervals to wash the packing and keep it moist. The bottom of the alkali solution cylinder (214) is provided with a discharge valve (215). The spraying assembly (270) sprays alkali solution onto the packing cylinder (212). The absorption component (1) absorbs toxic gas and sends the toxic gas into the absorption tower (2), which includes a toxic gas early warning unit. When the toxic gas early warning unit is activated, it triggers the discharge valve (215) to open and discharge alkaline solution.

2. The accidental chlorine absorption and treatment device for trichloroethylene production according to claim 1, characterized in that, The bottom of the inner wall of the alkali solution cylinder (214) is set in an arc shape.

3. The accidental chlorine absorption and treatment device for trichloroethylene production according to claim 1, characterized in that, The spraying assembly (270) includes a spray pipe (271), which is fixedly connected to the bottom of the alkali cylinder (214). The spray pipe (271) is connected to the external connecting pipe (273) of the absorption tower (2) through a hose (272). When the toxic gas warning unit is turned on, it triggers all the alkali cylinders (214) to rise to the highest point.

4. The accidental chlorine absorption and treatment device for trichloroethylene production according to claim 1, characterized in that, The drive unit (250) includes a telescopic cylinder (252) and a drive pump (253). The alkali cylinder (214) is connected to the packing cylinder (212) through three telescopic cylinders (252). The telescopic cylinders (252) on the same alkali cylinder (214) form a group. Any two groups of telescopic cylinders (252) can be connected through the drive pump (253). When the drive pump (253) is working, it drives one group of telescopic cylinders (252) to contract and the other group of telescopic cylinders (252) to descend.

5. The accidental chlorine absorption and treatment device for trichloroethylene production according to claim 4, characterized in that, The drive pump (253) has a hydraulic oil tank, and the drive pump (253) can still draw hydraulic oil from any set of alkali cylinders (214) or replenish hydraulic oil to any set of alkali cylinders (214).

6. The accidental chlorine absorption and treatment device for trichloroethylene production according to claim 4, characterized in that, The telescopic cylinder (252) is connected to a three-way valve (251), and the two ends of the three-way valve (251) are respectively connected to the suction port and discharge port of the drive pump (253).

7. The accidental chlorine absorption and treatment device for trichloroethylene production according to claim 4, characterized in that, The telescopic cylinder (252) is equipped with a position sensor.

8. The accidental chlorine absorption and treatment device for trichloroethylene production according to claim 4, characterized in that, The telescopic cylinder (252) contracts when hydraulic oil is injected and extends when hydraulic oil is discharged. The cylinder body of the telescopic cylinder (252) is embedded in the alkaline solution cylinder (214).

9. The accidental chlorine absorption and treatment device for trichloroethylene production according to claim 1, characterized in that, The alkali cylinder (214) has a closed bottom and sidewalls, and the bottom of the packing cylinder (212) has a hollow structure and the sidewalls are closed.

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