Vacuum-pump-free absolute pressure reduction system of wet-process phosphoric acid concentration device

Abstract

The invention discloses a vacuum-pump-free absolute pressure reduction system for a wet-process phosphoric acid concentration device, which comprises a first fluorine absorption tower, a second fluorine absorption tower, an atmospheric condenser and a steam injection unit, and a difluorine tower pipeline is fixedly mounted between the first fluorine absorption tower and the second fluorine absorption tower; an inlet pipe for receiving and conveying fluorine tail gas is fixedly mounted on the first fluorine absorption tower, and a first fluorine absorption tower circulating tank communicated with the first fluorine absorption tower is arranged at the bottom of the first fluorine absorption tower; a second fluorine absorption tower circulating tank communicated with the second fluorine absorption tower is arranged at the bottom of the second fluorine absorption tower; a second fluorine absorption circulating pump for pumping circulating water in the second fluorine absorption tower circulating tank is mounted on one side of the second fluorine absorption tower circulating tank. According to the spraying device, the spraying area is effectively controlled by adjusting the spraying angle of the spraying head of the spraying device, so that gas-liquid contact is more sufficient in a limited pipeline, meanwhile, the spraying coverage area can be reduced, and the system resistance can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of waste gas purification, and more specifically to an absolute pressure reduction system without a vacuum pump for a wet-process phosphoric acid concentration device. Background Art

[0002] First, the steam generated during the concentration of wet phosphoric acid includes a large amount of water vapor and a very small amount of inert gas. When these steam encounter cooling water, the water vapor will condense and turn into liquid, and the cooling water flowing at a higher speed can take away the inert gas. However, if the flow rate of the cooling water is low, it is difficult for the non-condensable gas to be taken out by the cooling water. In this case, if the traditional tray spray and water curtain condenser are used for absorption condensation without using a vacuum pump or steam jet pump, the flow rate of the cooling water is low, resulting in low condensation efficiency of the steam and insufficient condensation.

[0003] The main difference between steam jet pumps and vacuum pumps is their operating principle and efficiency. Steam jet pumps use a high-velocity stream of steam to create negative pressure to draw in and move fluids, including gases and vapors. They can effectively extract non-condensable gases, especially when large volumes of fluids and gases need to be handled. The advantage of steam jet pumps is that they can handle fluids containing solid particles and do not require mechanical moving parts, so maintenance costs are low. However, steam jet pumps may not be as energy efficient as vacuum pumps, and in some applications more steam may be required to create the required vacuum.

[0004] A vacuum pump is a device that mechanically reduces system pressure. It is usually used to remove gases or vapors to create a vacuum in the system. In the wet phosphoric acid concentration process, a vacuum pump can help quickly remove water vapor and non-condensable gases produced during evaporation, thereby accelerating the concentration process. Compared with steam ejectors, vacuum pumps generally provide higher efficiency and more precise pressure control. However, vacuum pumps may not be suitable for handling fluids containing solid particles and may require more frequent maintenance.

[0005] The vacuum degree of the system after the main concentration device is increased mainly by a large amount of circulating water entering the atmospheric condenser to take away the gas in the vacuum equipment to create a vacuum. When the vacuum degree does not meet the production requirements, the steam injection unit is turned on to compensate.

[0006] The capacity of circulating water vacuum extraction is limited. The currently operating device can reach a vacuum of about 20KPa by circulating water extraction, and the circulating water volume required is 5000m³ / h. The vacuum degree required for normal operation of the device is about 13KPa, so it is necessary to turn on the steam injection unit for compensation; however, in actual use, the steam injection unit consumes medium-pressure steam pressure that can only reach 0.7-0.8Mpa, and the circulating water volume is 250m³ / h. Summary of the invention

[0007] In view of the problems existing in the prior art, the object of the present invention is to provide an absolute pressure reduction system without a vacuum pump for a wet-process phosphoric acid concentration device to solve the background technical problems.

[0008] To achieve the above object, the present invention adopts the following technical solution: A vacuum pump-free absolute pressure reduction system for a wet-process phosphoric acid concentration device comprises a first fluorine absorption tower, a second fluorine absorption tower, an atmospheric condenser and a steam injection unit, wherein a second fluorine tower pipeline is fixedly installed between the first fluorine absorption tower and the second fluorine absorption tower; An inlet pipe for receiving and transporting fluorine tail gas is fixedly installed on the first fluorine absorption tower, and a first fluorine absorption tower circulation tank connected to the first fluorine absorption tower is arranged at the bottom of the first fluorine absorption tower; The bottom of the second fluorine absorption tower is provided with a second fluorine absorption tower circulation tank connected thereto, one side of the second fluorine absorption tower circulation tank is provided with a second fluorine absorption circulation pump for sucking the internal circulating water, the output port of the second fluorine absorption circulation pump is fixedly provided with a liquid infusion pipe, and the second fluorine absorption tower and the second fluorine tower pipeline are both connected to the second fluorine absorption circulation pump through the liquid infusion pipe; The atmospheric condenser is connected to the second fluorine absorption tower through a pipeline, and the gas outlet of the atmospheric condenser is connected to the steam injection unit through a pipeline; The steam injection unit is provided with inlets for introducing medium-pressure steam and acidic circulating cooling water respectively, the bottom of the steam injection unit is provided with a recovery water tank connected thereto, and the water outlet of the atmospheric condenser is connected to the recovery water tank; Six first connecting tubes are integrally formed on the difluoro tower pipeline, and the six first connecting tubes are fixedly connected to the end of the infusion tube. The six first connecting tubes extend to the interior of the second fluorine absorption tower and are fixedly connected to a first anti-blocking spray nozzle. The spraying direction of the first anti-blocking spray nozzle is the same as the gas flow direction in the difluoro tower pipeline, and the spray angle range of the first anti-blocking spray nozzle is fifty to sixty degrees.

[0009] As a further description of the above technical solution: The first anti-blocking spray heads in the infusion pipe where the gas flows downstream are all located within the spraying range of the first anti-blocking spray heads adjacent upstream, and the downstream first anti-blocking spray heads are all located outside the spraying range of the first anti-blocking spray heads spaced upstream.

[0010] As a further description of the above technical solution: A first fluorine absorption circulation pump for pumping circulating water inside the first fluorine absorption tower is fixedly installed on the circulation tank of the first fluorine absorption tower, and a water outlet of the first fluorine absorption circulation pump is connected with the first fluorine absorption tower and the inlet pipe.

[0011] As a further description of the above technical solution: Three second connecting pipes are arranged inside the inlet pipe, the water outlet of the first fluorine absorption circulation pump is connected to the second connecting pipe, one end of the second connecting pipe extends to the inside of the inlet pipe and is fixedly connected to a second anti-blocking spray nozzle.

[0012] As a further description of the above technical solution: The spraying direction of the second anti-blocking spray nozzle is the same as the flow direction of the gas entering the pipe, and the spraying angle range of the second anti-blocking spray nozzle is fifty to sixty degrees.

[0013] As a further description of the above technical solution: The circulation tank of the first fluorine absorption tower is provided with a supplementary pipe connected to external process water.

[0014] As a further description of the above technical solution: The inlet pipe and the difluoro tower pipeline are both smoothly arranged.

[0015] Compared with the prior art, the advantages of the present invention are: This solution effectively controls the spraying area by adjusting the spraying angle of the nozzle of the spraying device, allowing the gas-liquid contact to be more complete in the limited pipeline, while reducing the coverage area of ​​the spray and lowering the system resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the system of the present invention; Figure 2 It is a schematic diagram of the process of wet-process phosphoric acid concentration of the present invention; Figure 3 It is a schematic cross-sectional structure diagram of the difluoro tower pipeline of the present invention; Figure 4 It is a schematic diagram of the cross-sectional structure of the inlet pipe of the present invention.

[0017] Description of the numbers in the figure: 100, first fluorine absorption tower; 110, inlet pipe; 111, second connecting pipe; 112, second anti-blocking spray nozzle; 120, first fluorine absorption tower circulation tank; 121, replenishing pipe; 130, first fluorine absorption circulation pump; 200, second fluorine absorption tower; 210, second fluorine absorption tower circulation tank; 220, second fluorine absorption circulation pump; 230, infusion pipe; 300, atmospheric condenser; 400, steam injection unit; 410, recovery water tank; 500, second fluorine tower pipeline; 510, first connecting pipe; 520, first anti-blocking spray nozzle. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention; See also Figure 1-4 , the present invention provides the following embodiments: The wet-process phosphoric acid concentration device has a vacuum pump-free absolute pressure reduction system, comprising a first fluorine absorption tower 100, a second fluorine absorption tower 200, an atmospheric condenser 300 and a steam injection unit 400, and a second fluorine tower pipeline 500 is fixedly installed between the first fluorine absorption tower 100 and the second fluorine absorption tower 200.

[0019] An inlet pipe 110 for receiving and transporting fluorine tail gas is fixedly installed on the first fluorine absorption tower 100 , and a first fluorine absorption tower circulation tank 120 communicating therewith is disposed at the bottom of the first fluorine absorption tower 100 .

[0020] A second fluorine absorption tower circulation tank 210 connected to the second fluorine absorption tower 200 is provided at the bottom thereof, a second fluorine absorption circulation pump 220 for pumping circulating water therein is installed on one side of the second fluorine absorption tower circulation tank 210, a liquid infusion pipe 230 is fixedly installed at the output port of the second fluorine absorption circulation pump 220, and the second fluorine absorption tower 200 and the second fluorine tower pipeline 500 are both connected to the second fluorine absorption circulation pump 220 via the liquid infusion pipe 230.

[0021] The atmospheric condenser 300 is connected to the second fluorine absorption tower 200 through a pipeline, and the gas outlet of the atmospheric condenser 300 is connected to the steam injection unit 400 through a pipeline.

[0022] The steam injection unit 400 is provided with inlets for introducing medium-pressure steam and acidic circulating cooling water respectively. The bottom of the steam injection unit 400 is provided with a recovery water tank 410 connected thereto. The water outlet of the atmospheric condenser 300 is connected to the recovery water tank 410 .

[0023] Six first connecting tubes 510 are integrally formed on the difluoro tower pipeline 500, and the six first connecting tubes 510 are all fixedly connected to the end of the infusion tube 230. The six first connecting tubes 510 extend to the interior of the second fluorine absorption tower 200 and are fixedly connected to the first anti-blocking spray head 520. The spraying direction of the first anti-blocking spray head 520 is the same as the gas flow direction in the difluoro tower pipeline 500, and the spray angle range of the first anti-blocking spray head 520 is fifty to sixty degrees.

[0024] The fluorine-containing tail gas is input into the interior of the first fluorine absorption tower 100 through the inlet pipe 110, and then sprayed and liquefied for absorption, wherein the water absorbing fluorine is collected into the interior of the first fluorine absorption tower circulation tank 120, and the remaining gas that is not completely purified is introduced into the interior of the second fluorine absorption tower 200 through the second fluorine tower pipeline 500, and the gas is further purified and absorbed, and the absorbed liquid is introduced into the second fluorine absorption tower circulation tank 210 for collection, wherein the second fluorine absorption circulation pump 220 extracts the circulating water in the second fluorine absorption tower circulation tank 210 and inputs it into the second fluorine absorption tower 200 again through the infusion pipe 230 for spraying to complete the cycle, and then the purified gas is further cooled and liquefied through the atmospheric condenser 300 to remove steam, wherein a large amount of circulating water enters the atmospheric condenser 300 to take away the gas in the equipment and generate a vacuum, and when the vacuum degree does not meet the production requirements, the medium-pressure steam and the acidic circulating cooling water are input into the steam injection unit 400 to form a high-speed steam flow, and the high-speed steam flow is used to generate negative pressure to inhale and move gas and steam, which can effectively extract non-condensable gases.

[0025] In this process, part of the circulating water drawn out by the second fluorine absorption circulation pump 220 is diverted through the infusion pipe 230, and then input into the six first connecting pipes 510, and the circulating water is sprayed out through the first anti-blocking spray nozzle 520, wherein the spray angle range of the first anti-blocking spray nozzle 520 is fifty to sixty degrees, thereby further allowing the gas-liquid contact to be more complete in the limited space of the difluoro tower pipeline 500, while reducing the coverage area of ​​the spray to reduce the system resistance, thereby reducing the vacuum usage requirements.

[0026] See also Figure 3 The first anti-blocking spray heads 520 through which the gas in the infusion pipe 230 flows downstream are all located within the spraying range of the first anti-blocking spray heads 520 adjacent to them upstream, and the first anti-blocking spray heads 520 downstream are all located outside the spraying range of the first anti-blocking spray heads 520 spaced upstream from them.

[0027] Ensure that the position of each first anti-blocking spray nozzle 520 is reasonably set within the limited pipeline, ensure the spraying range of the six first anti-blocking spray nozzles 520 and reduce the resistance in the pipeline at the same time.

[0028] See also Figure 1 , 2 4 , a first fluorine absorption circulation pump 130 for pumping circulating water inside the first fluorine absorption tower circulation tank 120 is fixedly installed, and a water outlet of the first fluorine absorption circulation pump 130 is connected to the first fluorine absorption tower 100 and the inlet pipe 110 .

[0029] The first fluorine absorption circulation pump 130 is used to circulate the circulating water of the first fluorine absorption tower circulation tank 120 to the first fluorine absorption tower 100 and the inside of the inlet pipe 110 for spraying.

[0030] Three second connecting pipes 111 are arranged inside the inlet pipe 110 , the water outlet of the first fluorine absorption circulation pump 130 is connected to the second connecting pipe 111 , one end of the second connecting pipe 111 extends to the inside of the inlet pipe 110 and is fixedly connected to a second anti-blocking spray nozzle 112 .

[0031] The spraying direction of the second anti-clogging spray nozzle 112 is the same as the flow direction of the gas entering the pipe 110, and the spraying angle range of the second anti-clogging spray nozzle 112 is fifty to sixty degrees.

[0032] Part of the circulating water drawn out by the first fluorine absorption circulation pump 130 is diverted through the infusion pipe 230, and then input into the second connecting pipe 111, and the circulating water is sprayed out through the second anti-clogging spray nozzle 112, wherein the spray angle range of the second anti-clogging spray nozzle 112 is fifty to sixty degrees, thereby further allowing the gas-liquid contact to be more complete in the limited space inlet pipe 110, while reducing the coverage area of ​​the spray to reduce the system resistance, thereby reducing the vacuum usage demand.

[0033] See also Figure 1 and Figure 2 A supplementary pipe 121 connected to external process water is provided on the first fluorine absorption tower circulation tank 120.

[0034] The circulating water lost in the first fluorine absorption tower 100 and the first fluorine absorption tower circulation tank 120 is replenished to ensure the absorption effect of the fluorine-containing gas.

[0035] The inlet pipe 110 and the difluoro tower pipeline 500 are both smoothly arranged.

[0036] The friction between the system inlet pipe 110 and the inner wall of the difluoro tower pipeline 500 is reduced, and the fluid resistance is reduced, thereby reducing the gas's requirement for vacuum.

[0037] The above is only a preferred specific implementation of the present invention; however, the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and its improved conception within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A vacuum pump-free absolute pressure reduction system for a wet-process phosphoric acid concentration device, characterized in that: It comprises a first fluorine absorption tower (100), a second fluorine absorption tower (200), an atmospheric condenser (300) and a steam injection unit (400), wherein a second fluorine tower pipeline (500) is fixedly installed between the first fluorine absorption tower (100) and the second fluorine absorption tower (200); An inlet pipe (110) for receiving and transporting fluorine tail gas is fixedly installed on the first fluorine absorption tower (100), and a first fluorine absorption tower circulation tank (120) connected to the first fluorine absorption tower (100) is arranged at the bottom of the first fluorine absorption tower (100); A second fluorine absorption tower circulation tank (210) connected to the second fluorine absorption tower (200) is provided at the bottom thereof, a second fluorine absorption tower circulation tank (210) is installed on one side of the second fluorine absorption tower circulation tank (210) for pumping circulating water therein, a liquid infusion pipe (230) is fixedly installed at the output port of the second fluorine absorption circulation pump (220), and the second fluorine absorption tower (200) and the second fluorine tower pipeline (500) are both connected to the second fluorine absorption circulation pump (220) via the liquid infusion pipe (230); The atmospheric condenser (300) is connected to the second fluorine absorption tower (200) through a pipeline, and the gas outlet of the atmospheric condenser (300) is connected to the steam injection unit (400) through a pipeline; The steam injection unit (400) is provided with inlets for respectively introducing medium-pressure steam and acidic circulating cooling water, the bottom of the steam injection unit (400) is provided with a recovery water tank (410) connected thereto, and the water outlet of the atmospheric condenser (300) is connected to the recovery water tank (410); Six first connecting tubes (510) are integrally formed on the difluoro tower pipeline (500), and the six first connecting tubes (510) are fixedly connected to the end of the infusion tube (230). The six first connecting tubes (510) extend into the interior of the second fluorine absorption tower (200) and are fixedly connected to a first anti-blocking spray nozzle (520). The spraying direction of the first anti-blocking spray nozzle (520) is the same as the gas flow direction in the difluoro tower pipeline (500), and the spraying angle range of the first anti-blocking spray nozzle (520) is fifty to sixty degrees.

2. The vacuum pump-free absolute pressure reduction system for wet-process phosphoric acid concentration device according to claim 1, characterized in that: The first anti-blocking spray heads (520) for gas flowing downstream in the infusion pipe (230) are all located within the spraying range of the first anti-blocking spray heads (520) adjacent to them upstream, and the downstream first anti-blocking spray heads (520) are all located outside the spraying range of the first anti-blocking spray heads (520) separated upstream.

3. The vacuum pump-free absolute pressure reduction system for wet-process phosphoric acid concentration device according to claim 1, characterized in that: A first fluorine absorption circulation pump (130) for pumping circulating water inside the first fluorine absorption tower circulation tank (120) is fixedly installed thereon, and a water outlet of the first fluorine absorption circulation pump (130) is connected to the first fluorine absorption tower (100) and the inlet pipe (110).

4. The vacuum pump-free absolute pressure reduction system for wet-process phosphoric acid concentration device according to claim 3, characterized in that: Three second connecting pipes (111) are arranged inside the inlet pipe (110); a water outlet of the first fluorine absorption circulation pump (130) is connected to the second connecting pipe (111); one end of the second connecting pipe (111) extends into the interior of the inlet pipe (110) and is fixedly connected to a second anti-blocking spray nozzle (112).

5. The vacuum pump-free absolute pressure reduction system for wet-process phosphoric acid concentration device according to claim 4, characterized in that: The spraying direction of the second anti-blocking spray nozzle (112) is the same as the flow direction of the gas entering the pipe (110), and the spraying angle range of the second anti-blocking spray nozzle (112) is fifty to sixty degrees.

6. The vacuum pump-free absolute pressure reduction system for wet-process phosphoric acid concentration device according to claim 1, characterized in that: The first fluorine absorption tower circulation tank (120) is provided with a supplementary pipe (121) connected to external process water.

7. The vacuum pump-free absolute pressure reduction system for wet-process phosphoric acid concentration device according to claim 1, characterized in that: The inlet pipe (110) and the difluoro tower pipeline (500) are both smoothly arranged.

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