Yellow phosphorus tail gas purification production line and purification method thereof

Abstract

The invention discloses a yellow phosphorus tail gas purification production line and a purification method thereof, and belongs to the technical field of yellow phosphorus tail gas purification. The yellow phosphorus tail gas purification production line is better in purification effect and higher in safety. By means of the pressure relief mechanism and the pressure stabilizing mechanism, the air pressure in the yellow phosphorus tail gas purification production line can be within a set range, and explosion caused by large air pressure fluctuation in the production line is effectively avoided; on the basis, yellow phosphorus tail gas is purified through the phosphorus removal mechanism, the water washing mechanism and the alkali washing mechanism, and the purification effect is guaranteed. When the yellow phosphorus tail gas purification production line is used for purifying the yellow phosphorus tail gas, the safety in the purification process is guaranteed, the yellow phosphorus tail gas purification effect is improved, the purified yellow phosphorus tail gas can be automatically adjusted to be stored or input into a user side, and waste of the yellow phosphorus tail gas is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of yellow phosphorus tail gas purification, and specifically relates to a yellow phosphorus tail gas purification production line and a purification method thereof. Background Art

[0002] Electric furnace is the main equipment for yellow phosphorus production. Qualified phosphate rock, silica and coke are mixed in a certain proportion and added to the electric furnace for reduction reaction at 1300-1500℃. The phosphorus-containing furnace gas is dusted, condensed and refined to obtain finished yellow phosphorus. The by-products slag and ferrophosphorus are discharged from the bottom of the furnace regularly. Therefore, there are strict requirements for the insulation materials, refractory materials and refractory brick structures in the furnace lining.

[0003] The exhaust gas coming out of the electric furnace generally has a temperature of about 57°C and contains CO, H2, elemental phosphorus P4, sulfur compounds, PH3 and other components. There are flammable and explosive components in it, and the fluctuation of the furnace condition of the yellow phosphorus electric furnace causes the pressure of the yellow phosphorus exhaust gas to fluctuate greatly when it is discharged. When air enters the exhaust system, an explosion may occur, and the phosphorus in the yellow phosphorus exhaust gas may adhere to the pipe process during the process of lowering the exhaust gas temperature, causing the pipe process to be blocked. In severe cases, the resistance in the pipe process may be too large, which not only affects the resource utilization of the yellow phosphorus exhaust gas, but also the yellow phosphorus in the exhaust gas cannot be effectively recovered, which is a waste and also harms the exhaust gas users. Summary of the invention

[0004] In view of the problem of how to provide a yellow phosphorus tail gas purification production line with better purification effect and higher safety in the prior art, the present invention provides a yellow phosphorus tail gas purification production line and a purification method thereof.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A yellow phosphorus tail gas purification production line comprises a yellow phosphorus tail gas outlet pipe, wherein the yellow phosphorus tail gas outlet pipe is provided with a pressure control system, a tail gas purification system, a tail gas storage system and a gas volume automatic control system;

[0007] The pressure control system includes a pressure relief mechanism and a pressure stabilizing mechanism. The pressure relief mechanism is used to release the pressure when the air pressure in the yellow phosphorus tail gas outlet pipe is greater than a set value, and the pressure stabilizing mechanism is used to stabilize the air pressure within a set range.

[0008] The tail gas purification system includes a dephosphorization mechanism, a water washing mechanism and an alkali washing mechanism;

[0009] The tail gas storage system comprises a gas collecting main pipe connected to the yellow phosphorus tail gas outlet pipe, and the gas collecting main pipe is connected to a user end and a wet gas cabinet;

[0010] The exhaust gas volume automatic control system comprises a gas production volume detection device for each yellow phosphorus electric furnace, a gas consumption detection device for each exhaust gas user, an exhaust gas extraction capacity adjustment device for each yellow phosphorus exhaust gas, and an automatic control device.

[0011] After adopting this technical solution, the pressure relief mechanism and the voltage stabilizing mechanism in the present invention can make the air pressure in the yellow phosphorus tail gas purification production line within the set range, effectively avoiding the explosion caused by large fluctuations in the air pressure in the production line; on this basis, the yellow phosphorus tail gas is purified by the dephosphorization mechanism, the water washing mechanism and the alkali washing mechanism to ensure the purification effect. The main functions of the gas volume automatic control system are: (1) According to the online detection of the gas production changes of each yellow phosphorus electric furnace, the automatic control device analyzes and timely adjusts the air extraction capacity of the yellow phosphorus tail gas extraction capacity adjustment device; (2) According to the online detection of the gas consumption changes of each yellow phosphorus tail gas user and the gas storage capacity of the wet gas holder, the automatic control device analyzes and timely adjusts the gas consumption of each user; (3) According to the online detection of the gas storage capacity of the wet gas holder at the maximum or minimum gas storage capacity, the automatic control device analyzes and timely adjusts the exhaust gas extraction volume of each yellow phosphorus electric furnace or the gas consumption of each tail gas user to ensure the balance of supply and demand of yellow phosphorus tail gas and the safety of the tail gas production line and distribution system. The yellow phosphorus tail gas purification production line provided by the present invention not only ensures the safety of the purification process, but also improves the purification effect of the yellow phosphorus tail gas. The purified yellow phosphorus tail gas can be automatically adjusted for storage or input to the user end, thereby avoiding the waste of yellow phosphorus tail gas.

[0012] Preferably, the dephosphorization mechanism includes a shell-and-tube cooler, which includes an air inlet, an exhaust port, a cooling water inlet and a cooling water outlet. The air inlet is arranged at the upper part of the shell-and-tube cooler, and the exhaust port is arranged at the lower part of the cooler. A tee is arranged at the exhaust port, one end of the tee is connected to the exhaust port, and the other two ends are respectively connected to a drain pipe and an exhaust pipe. An exhaust fan is arranged on the exhaust pipe, and the drain pipe is connected to a cold washing liquid pool.

[0013] Preferably, the cold washing liquid pool is connected to the cold washing nozzle arranged in the cooler through a cold washing liquid supply pipe, a cold washing liquid pump is arranged on the cold washing liquid supply pipe, the cooling water inlet is connected to one end of the cooling water supply pipe, the other end of the cooling water supply pipe is connected to the cooling water outlet, and the cooling water supply pipe is arranged in a circulating water cooling tower.

[0014] Preferably, the pressure stabilizing mechanism comprises a liquid storage tank, in which a liquid and a floating tank capable of floating in the liquid are arranged, the space between the floating tank and the liquid surface forms a pressure regulating chamber, the liquid storage tank is connected to a pressure stabilizing tube, one end of the pressure stabilizing tube is connected to the yellow phosphorus tail gas outlet pipe, and the other end extends out from the liquid and is located in the floating tank.

[0015] Preferably, the pressure relief mechanism includes a liquid sealing tank, in which liquid sealing liquid is arranged, the liquid sealing tank is connected to a pressure relief pipe, one end of the pressure relief pipe is connected to the yellow phosphorus tail gas outlet pipe, and the other end is located in the liquid sealing liquid, and a chimney is arranged on the liquid sealing tank.

[0016] After adopting this technical solution, by setting up two-level safety treatment devices, the first level is a pressure stabilizing mechanism, and the second level is a pressure relief mechanism. When the tail gas of the yellow phosphorus electric furnace is discharged, when the pressure is between 120-450Pa, it is considered to be a safe pressure, and the pressure relief mechanism will not discharge the tail gas of the yellow phosphorus electric furnace, and the floating tank of the pressure stabilizing mechanism can adjust the size of the pressure regulating chamber according to the pressure to achieve the regulation of the tail gas pressure of the yellow phosphorus electric furnace. When the tail gas of the yellow phosphorus electric furnace is greater than 450Pa, part of the gas will be discharged through the pressure relief mechanism to achieve the effect of pressure relief. At the same time, the liquid seal in the pressure relief mechanism can effectively prevent air from entering the liquid seal tank through the chimney and contacting with the higher temperature tail gas of the yellow phosphorus electric furnace to cause an explosion.

[0017] Preferably, the cold washing liquid pool is connected to the cold washing nozzle arranged in the cooler through a cold washing liquid supply pipe, a cold washing liquid pump is arranged on the cold washing liquid supply pipe, the cooling water inlet is connected to one end of the cooling water supply pipe, the other end of the cooling water supply pipe is connected to the cooling water outlet, and the cooling water supply pipe is arranged in a circulating water cooling tower.

[0018] After adopting this technical solution, the washed yellow phosphorus will be precipitated in the cold washing liquid pool from the drainage pipe. The yellow phosphorus will be precipitated in the lower part of the cold washing liquid pool, and the upper clear liquid side can be reserved as the cold washing liquid for the next cold washing to save water. The cooling water will be recycled after being cooled by the circulating water cooling tower to reduce water consumption.

[0019] Preferably, the gas collecting main pipe includes an air intake section, an air storage section and an air using section. The air storage section is located between the air using section and the air intake section. The air outlet of each yellow phosphorus tail gas purification production line is connected to the air intake section. The air using section is connected to each user end through several air supply pipes, and the air storage section is connected to the wet gas cabinet through a gas storage pipe.

[0020] After adopting this technical solution, the exhaust gas purified by each yellow phosphorus exhaust gas purification production line is concentrated in the gas collecting main for unified allocation. When the purification amount exceeds the demand of the user end, the excess purified exhaust gas can automatically enter the wet gas tank for storage. When the purification amount is not enough to support the demand of the user end, the exhaust gas in the wet gas tank is transported to the gas collecting main to meet the gas demand of the user end, which also effectively avoids gas waste.

[0021] Preferably, a yellow phosphorus tail gas total water seal is also provided on the yellow phosphorus tail gas outlet pipe, and the yellow phosphorus tail gas total water seal is located before the pressure control system, the tail gas purification system and the tail gas storage system.

[0022] After adopting this technical solution, the yellow phosphorus electric furnace and the yellow phosphorus tail gas extraction system are effectively connected and isolated. When the yellow phosphorus electric furnace produces yellow phosphorus tail gas, the yellow phosphorus tail gas can be extracted from the yellow phosphorus electric furnace after the water in the yellow phosphorus tail gas total water seal is discharged; when the yellow phosphorus electric furnace is shut down or overhauled, the yellow phosphorus electric furnace and the tail gas extraction system can be effectively isolated to ensure the safety of the production device after the yellow phosphorus electric furnace is filled with water.

[0023] A yellow phosphorus tail gas purification method is carried out using a yellow phosphorus tail gas purification production line, comprising the following steps:

[0024] Step 1: The yellow phosphorus tail gas to be purified is introduced into the yellow phosphorus tail gas outlet pipe, and the air pressure is adjusted by the pressure stabilizing mechanism so that the air pressure in the yellow phosphorus tail gas outlet pipe is stabilized within a set range. When the air pressure of the yellow phosphorus tail gas is greater than the set value, the pressure is released by the pressure relief mechanism;

[0025] Step 2: The yellow phosphorus tail gas whose pressure is controlled within a suitable range is purified by a dephosphorization mechanism, a water washing mechanism and an alkali washing mechanism to obtain purified yellow phosphorus tail gas;

[0026] Step 3: The obtained yellow phosphorus exhaust gas enters the gas collecting main pipe from the yellow phosphorus exhaust gas outlet pipe and is transported to the user end for use. The excess yellow phosphorus exhaust gas is automatically input into the wet gas holder for storage. When the purified yellow phosphorus exhaust gas does not meet the needs of the user end, the yellow phosphorus exhaust gas in the wet gas holder is transported to the yellow phosphorus exhaust gas outlet pipe for replenishment.

[0027] Preferably, the specific steps of removing phosphorus by the phosphorus removal mechanism in step 2 are as follows:

[0028] Step 21: passing the yellow phosphorus tail gas into a cooler that is cooled by heat exchange with cooling water to reduce the temperature of the yellow phosphorus tail gas, thereby condensing the yellow phosphorus in the yellow phosphorus tail gas in the heat exchange channel, and the purified yellow phosphorus tail gas is discharged from the cooler, and the temperature of the cooling water is maintained at the cooling temperature during the purification process;

[0029] Step 22: When the purification time reaches the set time, stop cooling the cooling water, and detect the temperature of the cooling water in real time. When the cooling water temperature rises to the melting point of yellow phosphorus due to the heat exchange temperature with the yellow phosphorus tail gas, spray a cold washing liquid with a temperature lower than the temperature of the yellow phosphorus tail gas into the heat exchange channel, so that the cold washing liquid forms a water curtain along the side wall of the heat exchange channel, thereby washing the condensed yellow phosphorus in the heat exchange channel;

[0030] Step 23: Cool the cooling water until the cooling water temperature drops to the set cooling temperature, then stop cooling and stop introducing the cold wash liquid, so as to realize continuous purification of the yellow phosphorus tail gas through this cycle.

[0031] After adopting the technical scheme, the present invention firstly exchanges heat with the yellow phosphorus tail gas through the cooling water in the cooler, so that the temperature of the yellow phosphorus tail gas is reduced, so that the yellow phosphorus in the yellow phosphorus tail gas is condensed on the side wall of the heat exchange channel, so as to achieve the effect of separating the phosphorus in the yellow phosphorus tail gas, and avoid condensing in the pipe path and blocking the pipeline in the subsequent process. After a certain thickness of yellow phosphorus is condensed, the cooling of the cooling water is stopped, and the temperature component of the cooling water is increased until the melting point of the yellow phosphorus is reached. The cooling water reaching the melting point of the yellow phosphorus is heat-exchanged with the yellow phosphorus adhering to the side wall of the heat exchange channel, so that the yellow phosphorus at the innermost side of the heat exchange channel is melted, so that the connection between the yellow phosphorus and the heat exchange channel is loosened, and even the yellow phosphorus is automatically separated from the side wall of the heat exchange channel under its own gravity. At this time, since the cold washing liquid is also introduced, the introduced cold washing liquid also flushes the yellow phosphorus remaining on the side wall of the heat exchange channel, so that the yellow phosphorus in the heat exchange channel is thoroughly cleaned by heating and water flushing, thereby achieving full recovery of the yellow phosphorus. After the cooling water temperature rises, the cold wash liquid introduced replaces the cooling water to continue heat exchange with the yellow phosphorus tail gas, thereby continuously cooling and purifying the yellow phosphorus tail gas.

[0032] Preferably, in step 22, spraying of the cold wash liquid begins 5-10 seconds after the temperature of the cooling water reaches the melting point of yellow phosphorus.

[0033] Preferably, the temperature of the cooling water in step 22 is 25-30°C.

[0034] Preferably, the temperature of the cold wash liquid in step 22 is 40-45° C., the pressure is normal pressure, the gas-liquid volume ratio is 140-160:1, and the gas flow rate is 4-6 m / s.

[0035] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0036] 1. The pressure relief mechanism and the pressure stabilizing mechanism in the present invention can make the air pressure in the yellow phosphorus tail gas purification production line within the set range, effectively avoiding the explosion caused by large fluctuations in the air pressure in the production line; on this basis, the yellow phosphorus tail gas is purified by the phosphorus removal mechanism, the water washing mechanism and the alkali washing mechanism to ensure the purification effect. The yellow phosphorus tail gas purification production line provided by the present invention not only ensures the safety of the purification process, but also improves the effect of yellow phosphorus tail gas purification. The purified yellow phosphorus tail gas can be automatically adjusted for storage or input into the user end, avoiding the waste of yellow phosphorus tail gas.

[0037] 2. In the present invention, two-stage safety treatment devices are provided, the first stage is a pressure stabilizing mechanism, and the second stage is a pressure relief mechanism. When the tail gas of the yellow phosphorus electric furnace is discharged, when the pressure is between 120-450Pa, it is considered to be a safe pressure, and the pressure relief mechanism will not discharge the tail gas of the yellow phosphorus electric furnace, while the floating tank of the pressure stabilizing mechanism can adjust the size of the pressure regulating chamber according to the pressure to achieve the regulation of the tail gas pressure of the yellow phosphorus electric furnace. When the tail gas of the yellow phosphorus electric furnace is greater than 450Pa, part of the gas will be discharged through the pressure relief mechanism to achieve the effect of pressure relief. At the same time, the liquid seal in the pressure relief mechanism can effectively prevent air from entering the liquid seal tank through the chimney and contacting with the yellow phosphorus electric furnace tail gas with a higher temperature to cause an explosion.

[0038] 3. The present invention firstly exchanges heat with the yellow phosphorus tail gas through the cooling water in the cooler, so that the temperature of the yellow phosphorus tail gas is reduced, so that the yellow phosphorus in the yellow phosphorus tail gas is condensed on the side wall of the heat exchange channel, so as to achieve the effect of separating the phosphorus in the yellow phosphorus tail gas, and avoid condensing in the pipe path and blocking the pipeline in the subsequent process. In the present invention, when a certain thickness of yellow phosphorus is condensed, the cooling of the cooling water is stopped, and the temperature component of the cooling water is increased until the melting point of the yellow phosphorus is reached. The cooling water reaching the melting point of the yellow phosphorus is heat-exchanged with the yellow phosphorus adhering to the side wall of the heat exchange channel, so that the yellow phosphorus at the innermost side of the heat exchange channel is melted, so that the connection between the yellow phosphorus and the heat exchange channel is loosened, and even automatically detaches from the side wall of the heat exchange channel under its own gravity. At this time, since cold washing liquid is also introduced, the introduced cold washing liquid also flushes the residual yellow phosphorus on the side wall of the heat exchange channel, so that the yellow phosphorus in the heat exchange channel is thoroughly cleaned by heating and water flushing, thereby achieving full recovery of the yellow phosphorus. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a structural schematic diagram of the present invention;

[0040] Figure 2 for Figure 1 A partial enlarged view of the middle A;

[0041] Among them, 1- yellow phosphorus tail gas total water seal, 2- pressure relief pipe, 3- liquid seal tank, 4- chimney, 5- liquid storage tank, 6- pressure stabilizing tube, 7- floating tank, 8- primary water washing tower, 9- secondary water washing tower, 10- water washing pump, 11- water washing tank, 12- cold washing nozzle, 13- shell and tube cooler, 14- cold washing pump, 15- induced air fan, 16- cold washing liquid tank, 17- circulating water cooling tower, 18- Venturi scrubber, 19- alkali washing pump, 20- alkali washing tank, 21- primary alkali washing tower, 22- secondary alkali washing tower, 23- wet gas cabinet, 24- gas using part, 25- gas storage part, 26- air intake part, 27- control system. DETAILED DESCRIPTION

[0042] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0043] In the description of the embodiments of the present application, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or are the positions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0044] Example 1

[0045] like Figure 1-2 As shown, a yellow phosphorus tail gas purification production line includes a yellow phosphorus tail gas outlet pipe, on which a pressure control system, a tail gas purification system, a tail gas storage system, and a tail gas volume automatic control system are provided;

[0046] The pressure control system includes a pressure relief mechanism and a pressure stabilizing mechanism. The pressure relief mechanism is used to release the pressure when the air pressure in the yellow phosphorus tail gas outlet pipe is greater than a set value, and the pressure stabilizing mechanism is used to stabilize the air pressure within a set range.

[0047] The tail gas purification system includes a dephosphorization mechanism, a water washing mechanism and an alkali washing mechanism;

[0048] The tail gas storage system includes a gas collecting main pipe connected to the yellow phosphorus tail gas outlet pipe, and the gas collecting main pipe is connected to the user end and the wet gas cabinet 23;

[0049] The exhaust gas volume automatic control system comprises a gas production volume detection device for each yellow phosphorus electric furnace, a gas consumption detection device for each exhaust gas user, an exhaust gas extraction capacity adjustment device for each yellow phosphorus exhaust gas, and a DCS automatic control device.

[0050] The dephosphorization mechanism includes a shell-and-tube cooler, which includes an air inlet, an exhaust port, a cooling water inlet and a cooling water outlet. The air inlet is arranged at the upper part of the shell-and-tube cooler, and the exhaust port is arranged at the lower part of the cooler. A three-way pipe is arranged at the exhaust port, one end of the three-way pipe is connected to the exhaust port, and the other two ends are respectively connected to a drain pipe and an exhaust pipe. An exhaust fan 15 is arranged on the exhaust pipe, and the drain pipe is connected to a cold washing liquid pool 16.

[0051] In this embodiment, the cold washing liquid pool 16 is connected to the cold washing nozzle 12 arranged in the shell-and-tube cooler through a cold washing liquid supply pipe, and a cold washing liquid pump is arranged on the cold washing liquid supply pipe. A refrigerator and a heater can be arranged in the cold washing liquid pool 16 as needed to make the cold washing liquid reach the required temperature. The cooling water inlet is connected to one end of the cooling water supply pipe, and the other end of the cooling water supply pipe is connected to the cooling water outlet. The cooling water supply pipe is arranged in a circulating water cooling tower 17. In this embodiment, the pressure stabilizing mechanism includes a liquid storage tank 5, and the liquid storage tank 5 is provided with a liquid and a floating tank 7 that can float in the liquid. The space between the floating tank 7 and the liquid surface forms a pressure regulating chamber. The liquid storage tank 5 is connected to a voltage stabilizing tube 6, and one end of the voltage stabilizing tube 6 is connected to the yellow phosphorus tail gas outlet pipe, and the other end extends out of the liquid and is located in the floating tank 7. The floating tank 7 is provided with a tank edge protruding outward, and a limit block is provided at the tank mouth of the liquid storage tank 5 corresponding to the tank edge, and the end face of the limit block is provided close to the liquid surface. When the floating tank 7 is gradually lifted up as the gas entering the pressure regulating chamber increases, when the tank mouth of the floating tank 7 reaches the limit block, the floating tank 7 can be limited to continue to float upward, so as to prevent the floating tank 7 from detaching from the liquid storage tank. In other embodiments, the liquid height can also be set lower to prevent the floating tank 7 from detaching from the liquid storage tank 5 after floating to the limit. In comparison, the limit block and the tank edge can be provided to set the liquid height higher when the height of the liquid storage tank 5 is consistent, thereby increasing the time for the exhaust gas to exchange with the liquid, and improving the exhaust gas cooling effect. The two-stage safety treatment device cooperates with the wet gas cabinet 23 to ensure the safety of yellow phosphorus tail gas purification and the full recycling of yellow phosphorus tail gas.

[0052] In this embodiment, the pressure relief mechanism includes a liquid sealing tank 3, in which a liquid sealing liquid is arranged, and the liquid sealing tank 3 is connected to a pressure relief pipe 2, one end of the pressure relief pipe 2 is connected to the yellow phosphorus tail gas outlet pipe, and the other end is located in the liquid sealing liquid, and a chimney 4 is arranged on the liquid sealing tank 3. In this embodiment, the liquid sealing liquid is water, and when the yellow phosphorus electric furnace tail gas is greater than 450Pa, part of the gas will be discharged through the pressure relief mechanism to achieve the effect of pressure relief, and at the same time, the liquid seal in the pressure relief mechanism can effectively prevent air from entering the liquid sealing tank 3 through the chimney and contacting with the yellow phosphorus electric furnace tail gas with a higher temperature to cause an explosion.

[0053] In this embodiment, the gas collecting main comprises an air inlet 26, an air storage 25 and an air using part 24. The air storage 25 is located between the air using part 24 and the air inlet 26. The air outlet of each yellow phosphorus tail gas purification production line is connected to the air inlet 26. The air using part 24 is connected to each user end through several air supply pipes, and the air storage 25 is connected to the wet gas cabinet 23 through an air storage pipe. In other embodiments, the tail ends of multiple yellow phosphorus tail gas purification production lines are connected to the air inlet 26, so the yellow phosphorus tail gas obtained by each yellow phosphorus tail gas purification production line is transported to the same gas collecting main for unified allocation for use and storage.

[0054] In this embodiment, a yellow phosphorus tail gas total water seal 1 is also provided on the yellow phosphorus tail gas outlet pipe, and the yellow phosphorus tail gas total water seal 1 is located before the pressure control system, the tail gas purification system and the tail gas storage system.

[0055] In this embodiment, the water washing mechanism includes a primary water washing tower 8 and a secondary water washing tower 9 connected in series, a water washing tank 11 is connected between the primary water washing tower 8 and the secondary water washing tower 9, and a water washing pump 10 is provided on the pipeline connecting the primary water washing tower 8 and the secondary water washing tower 9 to the water washing tank 11, and the water after washing in the primary water washing tower 8 and the secondary water washing tower 9 flows into the water washing tank 11 for storage, and then the water in the water washing tank 11 is transported to the primary water washing tower 8 and the secondary water washing tower 9 for recycling through the water washing pump 10. In other embodiments, only a primary water washing tower 8 or more water washing towers can be provided according to the impurity content in the yellow phosphorus tail gas.

[0056] In this embodiment, the alkali washing mechanism includes a first-level alkali washing tower 21 and a second-level alkali washing tower 22 connected in series, and the first-level alkali washing tower 21 and the second-level alkali washing tower 22 are connected to an alkali washing pool 20. The first-level alkali washing tower 21 and the second-level alkali washing tower 22 are connected to the alkali washing pool 20. The pipeline is provided with an alkali washing pump 19, and the alkali after alkali washing in the first-level alkali washing tower 21 and the second-level alkali washing tower 22 flows into the alkali washing pool 20 for storage, and then the alkali in the alkali washing pool 20 is transported to the first-level alkali washing tower 21 and the second-level alkali washing tower 22 for recycling. In other embodiments, only a first-level alkali washing tower 21 or more alkali washing towers can be provided according to the impurity content in the yellow phosphorus tail gas.

[0057] In this embodiment, the wet gas cabinet 23 is a multi-section wet gas cabinet. The specific size of the multi-section wet gas cabinet 23 is determined according to the amount of yellow phosphorus tail gas and can be selected as needed. In other embodiments, a single-section wet gas cabinet can also be selected. The structure of the wet gas cabinet 23 is the same as that of the prior art, so it will not be repeated here.

[0058] In this embodiment, a venturi scrubber is provided between the dephosphorization mechanism and the alkaline washing mechanism, and the washing effect can be enhanced by providing the venturi scrubber.

[0059] Example 2

[0060] A yellow phosphorus tail gas purification method is carried out using the yellow phosphorus tail gas purification production line described in Example 1, comprising the following steps:

[0061] Step 1: The yellow phosphorus tail gas to be purified is introduced into the yellow phosphorus tail gas outlet pipe, the yellow phosphorus tail gas first passes through the yellow phosphorus tail gas total water seal 1, and then the air pressure is adjusted by the pressure stabilizing mechanism to stabilize the air pressure in the yellow phosphorus tail gas outlet pipe within a set range, and when the air pressure of the yellow phosphorus tail gas is greater than the set value, the pressure is released through the pressure relief mechanism;

[0062] Step 2: The yellow phosphorus tail gas with pressure controlled within a suitable range passes through the water washing mechanism, namely the primary water washing tower 8 and the secondary water washing tower 9. The circulating water temperature of the two-stage water washing is about 57°C, and the dust in the tail gas is reduced from 30000mg / m 3 Purification to 3000mg / m 3 About, while removing a small amount of elemental phosphorus in the tail gas to avoid clogging the subsequent air intake fan, purification device and pipeline; the yellow phosphorus tail gas directly enters the shell and tube cooler 13 after coming out of the secondary water washing tower 9, and the cooling water with a temperature of 25°C is introduced into the shell and tube cooler 13, so that the cooling water and the yellow phosphorus tail gas are heat exchanged, so that the phosphorus in the yellow phosphorus tail gas is condensed on the inner wall of the tube, thereby purifying the yellow phosphorus tail gas, and at the same time, a cold washing liquid with a temperature of 25°C is discharged, so that the cold washing liquid can form a washing water film on the inner wall of the tube to wash and drop the liquid yellow phosphorus condensed and attached to the tube wall; in addition to greatly reducing the elemental phosphorus in the tail gas, the shell and tube cooler 13 can also further reduce the content of dust in the tail gas to 900mg / m 3 The yellow phosphorus tail gas is pressurized by the induced air fan 15 and enters the venturi scrubber 18. The yellow phosphorus tail gas is mixed with the atomized washing liquid at the throat of the venturi scrubber 18 (gas-liquid ratio 150:1). The jet velocity is 200-220 m / s. The heat and mass transfer are fully carried out in the diffusion tube of the venturi scrubber 18. According to the temperature of the cold washing liquid, the elemental phosphorus in the yellow phosphorus tail gas is reduced to 0.6 g / m 3 Below, the dust in the tail gas is further removed to reduce it to 180mg / m 3 After the yellow phosphorus tail gas comes out of the venturi scrubber 18, it enters the primary alkali scrubber 21 and the secondary alkali scrubber 22, and is mixed with the alkali washing liquid (such as lime emulsion, temperature 35-4°C, concentration of about 10%) from the alkali washing tank for washing. The alkali liquid reacts with the acidic medium (such as HF, H2S) and saturated elemental phosphorus in the tail gas to remove the acidic medium and further reduce the elemental phosphorus and dust in the tail gas to 0.3g / m 3 Below and 30mg / m 3 The yellow phosphorus tail gas after purification is obtained. In this embodiment, the residual amount of yellow phosphorus on the inner wall of the tube after purification is as low as 0.159 g / m 2 ;

[0063] Step 3: The obtained yellow phosphorus exhaust gas enters the gas collecting main pipe from the yellow phosphorus exhaust gas outlet pipe and is transported to the user end for use. The excess yellow phosphorus exhaust gas is automatically input into the wet gas holder 23 for storage. When the purified yellow phosphorus exhaust gas does not meet the needs of the user end, the yellow phosphorus exhaust gas in the wet gas holder 23 is transported to the yellow phosphorus exhaust gas outlet pipe for replenishment.

[0064] Example 3

[0065] This embodiment is substantially the same as the embodiment 2, except that: the specific steps of removing phosphorus by the phosphorus removal mechanism in step 2 are as follows: step 21: passing the yellow phosphorus tail gas into the tubular cooler 13, so that the yellow phosphorus tail gas with a temperature of 57° C. is heat exchanged with the cooling water with a temperature of 25° C., so that the temperature of the yellow phosphorus tail gas is reduced, so that the yellow phosphorus in the yellow phosphorus tail gas is condensed in the heat exchange channel, the temperature of the cooling water is monitored in real time, and the cooling water is continuously circulated and cooled through the circulating water cooling tower 6, so that the temperature of the cooling water is maintained at about 25° C. during the purification process, and the purified yellow phosphorus tail gas is discharged from the cooler;

[0066] Step 22: When the purification time reaches 1 hour, stop cooling the cooling water (i.e. stop passing the cooling water into the circulating water cooling tower 6 for cooling), and continue to detect the temperature of the cooling water in real time. When the cooling water temperature rises to the melting point of yellow phosphorus 5 seconds after the heat exchange temperature with the yellow phosphorus tail gas, spray a cold wash liquid with a temperature of 40°C into the heat exchange channel, so that the cold wash liquid forms a water curtain along the side wall of the heat exchange channel, thereby washing the condensed yellow phosphorus in the heat exchange channel; the cold wash liquid and the yellow phosphorus electric furnace tail gas pass through the cooler heat exchange channel from top to bottom in the same direction, which not only ensures the heat and mass transfer between gas and liquid, but also ensures that the yellow phosphorus and dust dissolved in the cold wash liquid are not blocked on the water film cold wash heat exchange tube; the cooling water flows from bottom to top in the shell side of the cooler, ensuring the heat exchange efficiency;

[0067] Step 23: The cold wash liquid is heat exchanged with the cooling water and the yellow phosphorus tail gas, and the cooling water is continuously passed into the circulating water cooling tower 6 for cooling until the cooling water temperature drops to 25°C, after which the cold wash liquid is stopped, so that the yellow phosphorus tail gas is continuously purified in this cycle. In this embodiment, the residual amount of yellow phosphorus on the inner wall of the tube after purification is as low as 0.034 g / m 2 ;

[0068] The above-mentioned embodiments only express the specific implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the protection scope of the present application. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the technical solution concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. A yellow phosphorus tail gas purification production line, characterized by: It includes a yellow phosphorus tail gas outlet pipe, on which a pressure control system, a tail gas purification system, a tail gas storage system and a gas volume automatic control system are arranged; The pressure control system includes a pressure relief mechanism and a pressure stabilizing mechanism. The pressure relief mechanism is used to release the pressure when the air pressure in the yellow phosphorus tail gas outlet pipe is greater than a set value, and the pressure stabilizing mechanism is used to stabilize the air pressure within a set range. The tail gas purification system includes a dephosphorization mechanism, a water washing mechanism and an alkali washing mechanism; The tail gas storage system comprises a gas collecting main pipe connected to the yellow phosphorus tail gas outlet pipe, and the gas collecting main pipe is connected to a user end and a wet gas cabinet (23); The exhaust gas volume automatic control system comprises a gas production volume detection device for each yellow phosphorus electric furnace, a gas consumption detection device for each exhaust gas user, an exhaust gas extraction capacity adjustment device for each yellow phosphorus exhaust gas, and an automatic control device.

2. A yellow phosphorus tail gas purification production line according to claim 1, characterized in that: The dephosphorization mechanism comprises a shell-and-tube cooler, the shell-and-tube cooler comprises an air inlet, an exhaust port, a cooling water inlet and a cooling water outlet, the air inlet is arranged at the upper part of the shell-and-tube cooler, the exhaust port is arranged at the lower part of the cooler, a three-way pipe is arranged at the exhaust port, one end of the three-way pipe is connected to the exhaust port, and the other two ends are respectively connected to a drain pipe and an exhaust pipe, an exhaust pipe is arranged on the exhaust pipe, and the drain pipe is connected to a cold wash liquid pool (16).

3. A yellow phosphorus tail gas purification production line according to claim 2, characterized in that: The cold washing liquid pool (16) is connected to a cold washing nozzle (12) arranged in a cooler through a cold washing liquid supply pipe, a cold washing liquid pump is arranged on the cold washing liquid supply pipe, the cooling water inlet is connected to one end of the cooling water supply pipe, the other end of the cooling water supply pipe is connected to the cooling water outlet, and the cooling water supply pipe is arranged in a circulating water cooling tower (17).

4. A yellow phosphorus tail gas purification production line according to any one of claims 1 to 3, characterized in that: The pressure stabilizing mechanism comprises a liquid storage tank (5), wherein the liquid storage tank (5) is provided with liquid and a floating tank (7) capable of floating in the liquid, wherein the space between the floating tank (7) and the liquid surface forms a pressure regulating chamber, and the liquid storage tank (5) is connected to a pressure stabilizing tube (6), wherein one end of the pressure stabilizing tube (6) is connected to a yellow phosphorus tail gas outlet pipe, and the other end of the pressure stabilizing tube (6) extends out of the liquid and is located in the floating tank (7).

5. A yellow phosphorus tail gas purification production line according to any one of claims 1 to 3, characterized in that: The pressure relief mechanism comprises a liquid sealing tank (3), a liquid sealing liquid is arranged in the liquid sealing tank (3), the liquid sealing tank (3) is connected to a pressure relief pipe (2), one end of the pressure relief pipe (2) is connected to a yellow phosphorus tail gas outlet pipe, and the other end is located in the liquid sealing liquid, and a chimney (4) is arranged on the liquid sealing tank (3).

6. A yellow phosphorus tail gas purification production line according to any one of claims 1 to 3, characterized in that: The gas collecting main pipe comprises an air inlet (26), an air storage (25) and an air using section (24); the air storage (25) is located between the air using section (24) and the air inlet (26); the air outlet of each yellow phosphorus tail gas purification production line is connected to the air inlet (26); the air using section (24) is connected to each user end through a plurality of air supply pipes; and the air storage (25) is connected to a wet gas cabinet (23) through an air storage pipe.

7. A yellow phosphorus tail gas purification production line according to any one of claims 1 to 3, characterized in that: The yellow phosphorus tail gas outlet pipe is also provided with a yellow phosphorus tail gas total water seal (1), and the yellow phosphorus tail gas total water seal (1) is located before the pressure control system, the tail gas purification system and the tail gas storage system.

8. A yellow phosphorus tail gas purification method, characterized in that: The yellow phosphorus tail gas purification production line according to claims 1 to 7 is used, comprising the following steps: Step 1: The yellow phosphorus tail gas to be purified is introduced into the yellow phosphorus tail gas outlet pipe, and the air pressure is adjusted by a pressure stabilizing mechanism so that the air pressure in the yellow phosphorus tail gas outlet pipe is stabilized within a set range. When the air pressure of the yellow phosphorus tail gas is greater than the set value, the pressure is released by a pressure relief mechanism; Step 2: The yellow phosphorus tail gas whose pressure is controlled within a suitable range is purified by a dephosphorization mechanism, a water washing mechanism and an alkali washing mechanism to obtain purified yellow phosphorus tail gas; Step 3: The purified yellow phosphorus tail gas enters the gas collecting main pipe from the yellow phosphorus tail gas outlet pipe and is transported to the user end for use. The excess yellow phosphorus tail gas is automatically input into the wet gas holder (23) for storage. When the purified yellow phosphorus tail gas does not meet the needs of the user end, the yellow phosphorus tail gas in the wet gas holder (23) is transported to the yellow phosphorus tail gas outlet pipe for replenishment.

9. A yellow phosphorus tail gas purification method according to claim 8, characterized in that: The specific steps of removing phosphorus by the phosphorus removal mechanism in step 2 are as follows: Step 21: passing the yellow phosphorus tail gas into a cooler that is cooled by heat exchange with cooling water to reduce the temperature of the yellow phosphorus tail gas, thereby condensing the yellow phosphorus in the yellow phosphorus tail gas in the heat exchange channel, and the purified yellow phosphorus tail gas is discharged from the cooler, and the temperature of the cooling water is maintained at the cooling temperature during the purification process; Step 22: When the purification time reaches the set time, stop cooling the cooling water, and detect the temperature of the cooling water in real time. When the cooling water temperature rises to the melting point of yellow phosphorus due to the heat exchange temperature with the yellow phosphorus tail gas, spray a cold washing liquid with a temperature lower than the temperature of the yellow phosphorus tail gas into the heat exchange channel, so that the cold washing liquid forms a water curtain along the side wall of the heat exchange channel, thereby washing the condensed yellow phosphorus in the heat exchange channel; Step 23: Cool the cooling water until the cooling water temperature drops to the set cooling temperature, then stop cooling and stop introducing the cold wash liquid, so as to realize continuous purification of the yellow phosphorus tail gas through this cycle.

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