Hydrochloric acid ground tank tail gas treatment device

Abstract

The utility model discloses a hydrochloric acid ground tank tail gas treatment device which comprises a hydrochloric acid ground tank, a water washing mechanism, an alkali washing mechanism and an induced draft fan, the water washing mechanism comprises a water washing tower and a pure water circulating tank; a gas inlet of the water washing tower is communicated with a vent nozzle of the hydrochloric acid ground tank; a water outlet of the pure water circulating tank is communicated with a water inlet of the water scrubber; the alkali washing mechanism comprises an alkali washing tower and an alkali liquor circulating tank; an air inlet of the alkali washing tower is communicated with an air outlet of the water washing tower through an air supply pipe; a liquid outlet of the alkali liquor circulating tank is communicated with a liquid inlet of the alkaline washing tower; the induced draft fan is communicated with an exhaust port at the top of the alkaline tower through an exhaust pipe; wherein the air supply pipe is communicated with the exhaust pipe through a connecting air pipe, and a bypass valve is installed on the connecting air pipe. According to the utility model, the acidic hydrogen chloride gas is converted into gas meeting the emission standard after water washing and alkali washing, the hydrogen chloride content in the gas meets the atmospheric emission requirement, the working environment of a salt manufacturing site is improved, and meanwhile, generated waste acid and waste alkali can be completely recycled, so that the device has certain social benefits.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of volatile gas treatment technology of salt making industry, more particularly to a hydrochloric acid ground tank tail gas treatment device. BACKGROUND

[0002] Hydrochloric acid is an aqueous solution of hydrogen chloride (HCl) and is widely used in industry. Hydrochloric acid is a colorless transparent liquid with a strong pungent odor and high corrosiveness. Concentrated hydrochloric acid (mass fraction of about 37%) has very strong volatility, so when the container containing concentrated hydrochloric acid is opened, hydrogen chloride gas will volatilize, combine with water vapor in the air to form small droplets of hydrochloric acid, and acid mist will appear above the bottle opening. Hydrogen chloride is a toxic and suffocating gas that has a strong irritating effect on the upper respiratory tract and strong corrosive effect on the eyes, skin and mucous membranes. The maximum allowable concentration of this gas in the air is 15mg / m 3 .

[0003] The injection well water used by the brine extraction device in the salt making industry mainly comes from the condensate water produced by the vacuum salt making device, which contains a large amount of calcium ions and carbonate ions. Under alkaline conditions, it is easy to form scale in the pipeline, valve and pump shell, causing pipeline and valve blockage, corrosion damage to the impeller of the brine extraction pump and reduction of operating efficiency. Therefore, a small amount of hydrochloric acid needs to be added to adjust the pH value of the injection well water to create a slightly acidic environment to prevent scale formation. However, the vent of the hydrochloric acid ground tank will continuously volatilize hydrogen chloride, polluting the environment, corroding the pipeline equipment and to some extent affecting the health of the surrounding personnel.

[0004] Therefore, how to provide a tail gas treatment device that can improve the salt making site environment and ensure that the hydrogen chloride content meets the atmospheric emission requirements is a problem that needs to be solved by those skilled in the art. UTILITY MODEL CONTENT

[0005] Therefore, the utility model provides a hydrochloric acid ground tank tail gas treatment device, which completely solves the problem of direct discharge of volatile hydrogen chloride tail gas from the hydrochloric acid ground tank in the salt making industry.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A hydrochloric acid ground tank tail gas treatment device, comprising a hydrochloric acid ground tank, a water washing mechanism, an alkali washing mechanism and a induced draft fan;

[0008] The water washing mechanism comprises a water washing tower and a pure water circulating tank, and the bottom end gas inlet of the water washing tower is connected to the vent of the hydrochloric acid ground tank through a vent pipe; the water outlet of the pure water circulating tank is connected to the top water inlet of the water washing tower through a water pipe;

[0009] The alkali washing mechanism comprises an alkali washing tower and an alkali solution circulating tank, and the bottom end gas inlet of the alkali washing tower is communicated with the top end gas outlet of the water washing tower through a gas feeding pipe; the liquid outlet of the alkali solution circulating tank is communicated with the top liquid inlet of the alkali washing tower through an alkali solution conveying pipe;

[0010] The air inlet of the induced draft fan is communicated with the exhaust gas outlet at the top end of the alkali washing tower through an exhaust pipe to exhaust the treated gas into the atmosphere; wherein the gas feeding pipe and the exhaust pipe are communicated through a connecting gas pipe, and a bypass valve is installed on the connecting gas pipe.

[0011] The hydrogen chloride gas in the hydrochloric acid tank enters the water washing tower through the vent pipe, and the gas after water washing enters the alkali washing tower through the gas feeding pipe; the water in the pure water circulating tank is sent into the top of the water washing tower through the water pipe and reacts with the hydrogen chloride gas to generate an acidic solution; the alkaline liquid in the alkali solution circulating tank is sent into the alkali washing tower through the alkali solution conveying pipe and reacts with the acidic hydrogen chloride gas to generate a neutralization reaction, and the gas after the reaction is exhausted into the atmosphere by the induced draft fan; when the concentration of hydrogen chloride in the gas detected at the outlet of the induced draft fan is less than 15 mg / m 3 , the bypass valve can be opened, the water washing mechanism works, and the alkaline mechanism does not work, thereby saving energy and reducing consumption.

[0012] Preferably, the vent pipe is provided with a vent valve at one end corresponding to the hydrochloric acid tank, and a water washing gas inlet valve is installed at one end of the vent pipe corresponding to the water washing tower. The vent valve can control the flow of hydrogen chloride gas in the hydrochloric acid tank along the vent pipe, and the water washing gas inlet valve can control the flow of hydrogen chloride gas in the vent pipe into the water washing tower.

[0013] Preferably, the tank body of the hydrochloric acid tank is further provided with an air inlet, and an air inlet valve is fixed at the air inlet, and the air inlet valve is communicated with the fan through a gas pipe to blow clean air into the tank body of the hydrochloric acid tank and blow the hydrogen chloride gas in the tank into the vent pipe through the vent valve. Clean air can be blown into the hydrochloric acid tank by the fan to displace the hydrogen chloride gas into the vent pipe, and then into the water washing tower for water washing and into the alkali washing tower for alkaline. The air blown by the fan can accelerate the flow of hydrogen chloride gas, thereby improving the purification efficiency of hydrogen chloride gas.

[0014] Preferably, a water pump is arranged on the water pipe to pump the water in the pure water circulating tank into the water washing tower; and a water pump inlet valve and a water pump outlet valve are respectively fixed on the water pipe relative to the inlet and outlet ends of the water pump.

[0015] Preferably, a plurality of water washing tower tray distributors are fixed in the water washing tower along the height direction of the water washing tower; and a spray head is fixed on the end of the water pipe away from the pure water circulating tank and located at the top of the water washing tower inner cavity.

[0016] The beneficial effects of the above technical solution are that the water pump pumps water into the water washing tower, the water in the water washing tower is sprayed on the water washing tower tray distributor through the spray head, the water washing tower tray distributor can uniformly distribute the water on the tray to achieve uniform and comprehensive absorption of hydrogen chloride gas, the acidic solution generated after the reaction of water and hydrogen chloride falls into the bottom of the water washing tower, and the gas after spraying moves upward and enters the alkali washing tower through the gas outlet of the water washing tower and the gas pipe, or is directly discharged into the atmosphere through the exhaust pipe by using the induced draft fan.

[0017] Preferably, the water bucket is further included, an acid liquid overflow port is arranged on the bottom side wall of the water washing tower, the acid liquid overflow port is communicated with the pure water circulating tank through an acid liquid overflow pipe, and a water outlet valve is fixed on the pipeline between the water pipe and the water pump outlet valve.

[0018] The water outlet of the water bucket is fixedly communicated with the side wall of the acid liquid overflow pipe through a water inlet valve, and the water inlet of the water bucket is communicated with the water outlet valve.

[0019] The beneficial effects of the above technical solution are that the water bucket overflows water into the pure water circulating tank through the water inlet valve; as the water washing proceeds, the water in the pure water circulating tank gradually decreases, the acidic liquid formed at the bottom of the water washing tower enters the pure water circulating tank through the acid liquid overflow pipe, at this time, the concentration of the acid liquid in the pure water circulating tank increases, when the acidity reaches a certain threshold, the water outlet valve is opened to pump the acidic solution in the pure water circulating tank into the water bucket, and pure water is supplemented into the water bucket to dilute the acidic solution, and the diluted solution can be overflowed into the pure water circulating tank through the water inlet valve for water washing operation.

[0020] Preferably, an alkali liquid circulating pump is arranged on the alkali liquid conveying pipe to pump the alkali liquid in the alkali liquid circulating tank to the alkali washing tower, and an alkali liquid pump inlet valve and an alkali liquid pump outlet valve are respectively fixed on the pipelines opposite the liquid inlet end and the liquid outlet end of the alkali liquid circulating pump.

[0021] Preferably, the alkali washing tower comprises a tower body and an alkali washing tower tray distributor and a CPVC plum blossom ring filler layer arranged in the tower body from top to bottom; one end of the gas pipe close to the alkali washing tower is fixed with an alkali washing gas inlet valve; and one end of the alkali liquid conveying pipe away from the alkali liquid circulating tank is fixed with an alkali liquid spray head and located at the top of the inner cavity of the alkali washing tower.

[0022] The beneficial effects of the above technical solution are that the alkali liquid circulating pump pumps the alkaline liquid into the alkali washing tower, the tray distributor in the alkali washing tower can uniformly distribute the alkali liquid on the tray, and the CPVC plum blossom ring filler layer can increase the contact area of the gas and the liquid, the acidic hydrogen chloride gas and the alkaline liquid neutralize to form a salt liquid, and the salt liquid is collected at the bottom of the alkali washing tower.

[0023] Preferably, the brine reaction barrel further comprises a caustic solution overflow port formed in the bottom side wall of the caustic washing tower, the caustic solution overflow port is communicated with the caustic solution circulating tank through a caustic solution overflow pipe, and a liquid outlet valve is fixed on the pipeline between the caustic solution pump outlet valve and the caustic solution circulating pump.

[0024] The water outlet of the brine reaction barrel is fixedly communicated with the side wall of the caustic solution overflow pipe through a liquid inlet valve, and the water inlet of the brine reaction barrel is communicated with the liquid outlet valve.

[0025] The brine reaction barrel injects caustic solution into the caustic solution circulating tank through the liquid inlet valve, the caustic solution is pumped into the caustic washing tower by the caustic solution circulating pump, and is fully contacted with hydrogen chloride gas through the spray head, so that hydrogen chloride in the gas is removed by acid-base neutralization reaction; the liquid after caustic washing flows into the caustic solution circulating tank through the caustic solution overflow pipe, and the caustic solution concentration in the caustic solution circulating pipe is reduced; when the caustic solution concentration is reduced to a certain value, the liquid outlet valve is opened to pump the low-concentration caustic solution into the brine reaction barrel, the low-concentration caustic solution reacts to generate salt crystals in the brine reaction barrel, fresh brine is supplemented into the brine reaction barrel to increase the caustic solution concentration, and the high-concentration caustic solution is re-injected into the caustic solution circulating tank to repeat the caustic washing operation.

[0026] Preferably, a fan inlet valve is fixed at one end of the exhaust pipe close to the induced draft fan, and an exhaust valve is fixed at the other end of the exhaust pipe, and the exhaust valve is located on the pipeline between the exhaust pipe and the connecting pipe and the caustic washing tower.

[0027] Compared with the prior art, the hydrochloric acid tank tail gas treatment device provided by the utility model can convert acidic hydrogen chloride gas into gas meeting the emission standard after water washing and caustic washing, the hydrogen chloride content in the gas meets the atmospheric emission requirement, the working environment of a salt production site is improved, waste acid and waste alkali can be fully recycled, and the utility model has certain social benefits. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiment or the prior art description will be briefly introduced below, and obviously, the drawings in the following description are only the embodiments of the utility model, and those skilled in the art can also obtain other drawings according to the provided drawings without creating labor.

[0029] Figure 1 The tail gas treatment device structure schematic view provided by the utility model.

[0030] wherein,

[0031] 1 - hydrochloric acid tank; 11 - emptying valve; 12 - air inlet valve;

[0032] 2 - water washing tower; 21 - water washing tower tray distributor; 22 - water washing air inlet valve;

[0033] 3 - pure water circulating tank; 31 - water inlet valve; 32 - blowdown valve; 33 - water outlet valve;

[0034] 4 - water pipe; 41 - water pump; 42 - water pump inlet valve; 43 - water pump outlet valve; 44 - spray head;

[0035] 5 - alkali washing tower; 51 - alkali washing air inlet valve; 52 - CPVC clover ring filler layer; 53 - alkali washing tower tray distributor; 54 - exhaust valve;

[0036] 6 - alkali liquor circulating tank; 61 - liquid inlet valve; 62 - liquid outlet valve;

[0037] 7 - alkali liquor conveying pipe; 71 - alkali liquor circulating pump; 72 - alkali liquor pump inlet valve; 73 - alkali liquor pump outlet valve; 74 - alkali liquor spray head;

[0038] 8 - induced draft fan; 81 - fan inlet valve;

[0039] 9 - bypass valve. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to 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 the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0041] Embodiment 1: The utility model embodiment discloses a kind of hydrochloric acid tank tail gas treatment device, including hydrochloric acid tank 1, water washing mechanism, alkali washing mechanism and induced draft fan 8;

[0042] Water washing mechanism includes water washing tower 2 and pure water circulating tank 3, and the water washing tower 2 bottom end air inlet is communicated with the emptying port of hydrochloric acid tank 1 by emptying pipe;The water outlet of pure water circulating tank 3 is communicated with the water inlet of water washing tower 2 top by water pipe 4;

[0043] Alkali washing mechanism includes alkali washing tower 5 and alkali liquor circulating tank 6, and the alkali washing tower 5 bottom end air inlet is communicated with the water washing tower 2 top end air outlet by gas feeding pipe;The liquid outlet of alkali liquor circulating tank 6 is communicated with the liquid inlet of alkali washing tower 5 top by alkali liquor conveying pipe 7;

[0044] The air inlet of the induced draft fan 8 is connected to the exhaust port at the top of the alkaline washing tower 5 through the exhaust pipe to discharge the treated gas into the atmosphere; the air supply pipe and the exhaust pipe are connected by a connecting air pipe, and a bypass valve 9 is installed on the connecting air pipe.

[0045] like Figure 1 As shown, after the hydrogen chloride gas in the hydrochloric acid tank enters the water washing tower through the vent pipe, water from the pure water circulation tank is injected into the water washing tower. The water reacts with the hydrogen chloride gas to generate an acidic solution, which can reduce the hydrogen chloride content in the gas. The gas after water washing enters the alkali washing tower. The alkaline liquid in the alkali circulation tank enters the alkali washing tower and reacts with the gas containing a small amount of hydrogen chloride to further reduce the hydrogen chloride content in the gas. When the hydrogen chloride content in the gas meets the requirements, the induced draft fan can be turned on to directly discharge the gas into the atmosphere.

[0046] In addition, when the hydrogen chloride concentration detected at the exhaust port of the induced draft fan is less than 15 mg / m3, the bypass valve can be opened, keeping only the connection between the water washing mechanism and the induced draft fan. The gas in the water washing tower can be directly discharged into the atmosphere through the connecting gas pipe, eliminating the alkaline washing step and effectively saving energy and reducing consumption.

[0047] To further optimize the above technical solution and control the flow of gas inside the hydrochloric acid tank, a vent valve 11 is installed at one end of the vent pipe corresponding to the hydrochloric acid tank 1, and a water washing inlet valve 22 is installed at the other end of the vent pipe corresponding to the water washing tower 2. When the vent valve is opened, the gas inside the hydrochloric acid tank can enter the vent pipe; when the water washing inlet valve is opened, the gas inside the vent pipe enters the water washing tower through the tail gas baffle.

[0048] In other specific embodiments, to improve the flow rate of hydrogen chloride gas (tail gas) inside the hydrochloric acid tank 1, an air inlet is also provided on the tank body. An air inlet valve 12 is fixed at the air inlet. The air inlet valve 12 is connected to a fan through an air pipe to blow clean air into the tank body of the hydrochloric acid tank 1 and blow the hydrogen chloride gas inside into the vent pipe through the vent valve 11. The air blown in by the fan replaces the volatilized hydrogen chloride gas in the water washing tower and the alkali washing tower.

[0049] In other specific embodiments, to improve the efficiency of water washing, a water pump 41 is installed on the water pipe 4 to pump water from the pure water circulation tank 3 to the water washing tower 2; a water pump inlet valve 42 and a water pump outlet valve 43 are respectively fixed on the water pipe 4 relative to the water pump 41 at the inlet and outlet ends. The injection of pure water into the water washing tower is completed by the water pump, and the flow of pure water is controlled by the water pump inlet valve and the water pump outlet valve.

[0050] In the embodiment, a plurality of water-washing tray distributors 21 are fixed in the water-washing tower 2 along the height direction of the water-washing tower 2; the water pipe 4 is fixed with a spray head 44 at the end away from the pure water circulating tank 3 and located at the top of the inner cavity of the water-washing tower 2. The water-washing tray distributor can uniformly distribute water on the tray. In the water-washing process, water is used as the absorbent for the treatment of hydrogen chloride tail gas. The water-washing tray distributor sprays liquid in the form of fine droplets or liquid film on the tray through its special structure (such as a spray head, a perforated plate or a groove distributor, etc.), thereby avoiding the local liquid accumulation or dryness on the tray and ensuring that the entire tray surface can be covered by liquid. The uniformly distributed water can maximize the contact area between water and hydrogen chloride gas, improve the mass transfer efficiency, and thus more effectively remove the hydrogen chloride content in the gas.

[0051] In order to further optimize the above technical solution, a water bucket is further included. An acid liquid overflow port is formed in the bottom side wall of the water-washing tower 2. The acid liquid overflow port is connected to the pure water circulating tank 3 through an acid liquid overflow pipe. The water pipe 4 is fixed with a water outlet valve 33 on the pipeline between the water pump outlet valve 43 and the water pump 41.

[0052] The water outlet of the water bucket is fixedly connected to the side wall of the acid liquid overflow pipe through a water inlet valve 31. The water inlet of the water bucket is connected to the water outlet valve 33.

[0053] When the water inlet valve is opened, the water in the water bucket overflows into the pure water circulating pipe. When the liquid level in the pure water circulating tank reaches a preset value, the water pump is started. The water pump injects water into the water-washing tower and reacts with the hydrogen chloride in the gas to produce acidic liquid. The acidic liquid enters the pure water circulating tank through the acid liquid overflow pipe from the acid liquid overflow port, so that the liquid acid concentration in the pure water circulating tank is increased. When the concentration reaches a certain degree, the water outlet valve is opened to inject the liquid acid into the water bucket, and pure water is added to the water bucket to dilute the liquid acid. After dilution, the pure water circulating tank is re-injected, and the water-washing operation is performed in a cycle.

[0054] In some other specific embodiments, in order to improve the delivery efficiency of the alkaline liquid, an alkaline liquid circulating pump 71 is arranged on the alkaline liquid delivery pipe 7 to pump the alkaline liquid in the alkaline liquid circulating tank 6 into the alkali-washing tower 5. Alkaline liquid pump inlet valves 72 and alkaline liquid pump outlet valves 73 are respectively fixed on the pipelines relative to the liquid inlet end and the liquid outlet end of the alkaline liquid circulating pump 71. The alkaline liquid is pumped into the alkali-washing tower by the alkaline liquid circulating pump, and the flow of the alkaline liquid is controlled by the alkaline liquid pump inlet valve and the alkaline liquid pump outlet valve.

[0055] In the embodiment, the alkali-washing tower 5 includes a tower body and an alkali-washing tray distributor 53 and a CPVC plum-pudding ring filler layer 52 arranged in the tower body from top to bottom. The gas delivery pipe is fixed with an alkali-washing gas inlet valve 51 at the end close to the alkali-washing tower 5. The alkaline liquid delivery pipe 7 is fixed with an alkaline liquid spray head 74 at the end away from the alkaline liquid circulating tank 6 and located at the top of the inner cavity of the alkali-washing tower 5.

[0056] The effect of the alkali washing tray distributor is the same as that of the water washing tray distributor, which will not be repeated here.

[0057] The CPVC (chlorinated polyvinyl chloride) quincunx filler layer is a common filler form in the tail gas treatment process. The quincunx filler is a regular filler, which has a shape similar to a plum blossom petal and has a large specific surface area. When the gas passes through the filler layer, the lye will flow along the surface of the filler to form a thin liquid film. Acid gases (such as HCl, SO2, HF, etc.) in the gas will react with the lye in the liquid film. The CPVC quincunx filler layer increases the gas-liquid contact area, promotes mass and heat transfer, prevents gas-liquid stratification and channeling, reduces the pressure drop in the tower, protects the tower body and equipment, adjusts the gas-liquid distribution, and adapts to different working conditions, thereby ensuring efficient, stable and economic operation of the tail gas treatment process.

[0058] To further optimize the above technical solution, a brine reaction barrel is further included, an alkali overflow port is formed in the side wall of the bottom of the alkali washing tower 5, the alkali overflow port is connected to the alkali circulation tank 6 through an alkali overflow pipe, and a liquid outlet valve 62 is fixed on the pipeline between the alkali pump outlet valve 73 and the alkali circulation pump 71 relative to the alkali delivery pipe 7.

[0059] The water outlet of the brine reaction barrel is fixedly connected to the side wall of the alkali overflow pipe through the liquid inlet valve 61, and the water inlet of the brine reaction barrel is connected to the liquid outlet valve 62.

[0060] The liquid inlet valve is opened, the brine reaction barrel injects the alkali washing liquid into the alkali circulation pipe, the alkali circulation pump is opened when the liquid level reaches a certain threshold, the alkali circulation pump injects the alkali into the alkali washing tower to react with hydrogen chloride in the gas, the salt solution after the reaction enters the alkali circulation tank through the alkali overflow port, the alkali concentration of the alkali circulation tank decreases due to the decrease of the alkali liquid level and the injection of the solution after the reaction, the liquid outlet valve is opened when the alkali concentration decreases to an extreme value, the liquid alkali enters the brine reaction barrel to react with the brine to generate salt crystals, new brine is added to the brine reaction barrel to increase the concentration of the liquid alkali, and the alkali is re-injected into the alkali circulation pipe after the concentration of the liquid alkali is qualified, and the alkali washing operation is repeatedly performed.

[0061] To further optimize the above technical solution, a fan inlet valve 81 is fixed to one end of the exhaust pipe close to the induced draft fan 8, and an exhaust valve 54 is fixed to the other end of the exhaust pipe, and the exhaust valve 54 is located on the pipeline between the exhaust pipe and the alkali washing tower 5 relative to the connected gas pipe. The gas after the water washing and alkali washing can be discharged into the atmosphere through the induced draft fan.

[0062] To further optimize the above technical solution, a blowdown port is formed in the bottom of the pure water circulation tank, a blowdown valve 32 is fixed to the blowdown port and connected to a blowdown pipe.

[0063] Open the blowdown valve, through the pure water circulating tank by periodic blowdown, prevent salt mud into the water washing tower and plug the tray, and then reduce the quality of the tail gas treatment.

[0064] Embodiment 2: The utility model discloses a kind of hydrochloric acid tank tail gas treatment methods, using the hydrochloric acid tank tail gas treatment device in embodiment 1 to process the hydrogen chloride gas volatilized in hydrochloric acid tank, including water washing procedure and alkali washing procedure;

[0065] Open the emptying valve and inlet valve of hydrochloric acid tank, open water washing inlet valve, alkali washing inlet valve and exhaust valve, close bypass valve, and open fan inlet valve.

[0066] Open the water inlet valve, and the water in the bucket overflows into the pure water circulating tank. When the liquid level in the pure water circulating tank reaches 70%, open the water pump inlet valve and the water pump outlet valve. The water pump works to pump water from the pure water circulating tank into the water washing tower. The water is evenly distributed on the water washing tray through the action of the spray head and the water washing tray distributor. The tail gas (hydrogen chloride gas) contacts the water washing tray to absorb particulate impurities and part of the hydrogen chloride ions. The generated acidic solution enters the pure water circulating tank through the acid overflow pipe. As the acid solution is injected, the concentration of the liquid acid in the pure water circulating tank gradually increases. The water-washed tail gas enters the alkali washing tower through the gas delivery pipe from the gas outlet of the water washing tower.

[0067] During the operation of the water pump, the liquid level in the pure water circulating tank needs to be maintained between 30% and 70%. The working pressure of the water washing tower is 10-25 KPa, and the temperature is less than 45℃.

[0068] When the concentration of liquid acid in the pure water circulating tank is greater than 23%, open the water outlet valve. The waste acid in the pure water circulating tank is pumped into the water bucket through the water pump and the water outlet valve. At the same time, open the water inlet valve to inject water into the pure water circulating tank. During this period, the liquid level in the pure water circulating tank needs to be maintained between 30% and 70%. When the concentration of the replaced liquid acid in the pure water circulating tank is less than 10%, close the water outlet valve.

[0069] It should be noted that the outlet flow of the water pump should not be too large to prevent the water washing tray distributor from accumulating liquid and causing the tail gas to pass through.

[0070] When the liquid level in the alkali liquor circulating tank reaches 70%, the alkali liquor pump inlet valve and the alkali liquor pump outlet valve are opened, the alkali liquor pump pumps the alkali liquor into the caustic washing tower, the alkali liquor is uniformly distributed through the spray head and the caustic washing tower distributor, the tail gas after water washing passes through the CPVC clover ring filler layer and the caustic washing tower distributor in turn from the tail gas baffle at the bottom of the caustic washing tower, the hydrogen chloride ions in the tail gas react with the alkali liquor, the reacted gas is discharged into the atmosphere through the exhaust pipe by the induced draft fan from the gas outlet of the caustic washing tower; the excess liquid overflows from the alkali liquor overflow port at the bottom of the caustic washing tower to the alkali liquor overflow pipe and then to the alkali liquor circulating tank, and the concentration of the liquid alkali in the alkali liquor circulating tank gradually decreases with the injection of the liquid.

[0071] During the caustic washing process, the liquid level in the alkali liquor circulating tank is maintained between 30% and 70%, the working pressure of the caustic washing tower is 15-30 KPa, and the temperature is less than 45℃.

[0072] When the concentration of the liquid alkali in the caustic washing circulating tank is less than 8%, the waste alkali is discharged to the brine reaction bucket by opening the liquid outlet valve, and fresh liquid alkali is injected into the alkali liquor circulating tank by opening the liquid inlet valve, during which the liquid level is maintained between 30% and 70%, and when the concentration of the replaced liquid alkali in the alkali liquor circulating tank is between 12 and 15%, the liquid outlet valve is closed.

[0073] During the tail gas treatment process, in order to reduce energy consumption, when the concentration of hydrogen chloride in the gas at the outlet of the induced draft fan is less than 15 mg / m 3 , the bypass valve can be opened, only the water washing mechanism is started, and the caustic washing mechanism is not started.

[0074] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments, and the same or similar parts between the various embodiments can be referred to each other. For the device disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple, and the related parts can be referred to the method part.

[0075] The above description of the disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A hydrochloric acid tank tail gas treatment device, characterized in that, Includes hydrochloric acid tank (1), water washing mechanism, alkaline washing mechanism and induced draft fan (8); The water washing mechanism includes a water washing tower (2) and a pure water circulation tank (3). The air inlet at the bottom of the water washing tower (2) is connected to the vent of the hydrochloric acid tank (1) through a vent pipe. The water outlet of the pure water circulation tank (3) is connected to the water inlet at the top of the water washing tower (2) through a water pipe (4). The alkaline washing mechanism includes an alkaline washing tower (5) and an alkaline circulation tank (6). The air inlet at the bottom of the alkaline washing tower (5) is connected to the air outlet at the top of the water washing tower (2) through an air supply pipe. The liquid outlet of the alkaline circulation tank (6) is connected to the liquid inlet at the top of the alkaline washing tower (5) through an alkaline delivery pipe (7). The air inlet of the induced draft fan (8) is connected to the exhaust port at the top of the alkaline washing tower (5) through the exhaust pipe to discharge the treated gas into the atmosphere; wherein, the gas supply pipe and the exhaust pipe are connected by a connecting gas pipe, and a bypass valve (9) is installed on the connecting gas pipe.

2. The hydrochloric acid tank tail gas treatment device according to claim 1, characterized in that, An vent valve (11) is installed at one end of the vent pipe corresponding to the hydrochloric acid tank (1), and a water washing inlet valve (22) is installed at one end of the vent pipe corresponding to the water washing tower (2).

3. The hydrochloric acid tank tail gas treatment device according to claim 2, characterized in that, An air inlet is provided on the tank body of the hydrochloric acid tank (1), and an air inlet valve (12) is fixed at the air inlet. The air inlet valve (12) is connected to a ventilator through an air pipe to blow clean air into the tank body of the hydrochloric acid tank (1) and blow the hydrogen chloride gas inside into the vent pipe through the vent valve (11).

4. The hydrochloric acid tank tail gas treatment device according to claim 1, characterized in that, A water pump (41) is provided on the water pipe (4) to pump the water in the pure water circulation tank (3) to the water washing tower (2); a water pump inlet valve (42) and a water pump outlet valve (43) are respectively fixed on the water pipe (4) at the water inlet end and the water outlet end relative to the water pump (41).

5. The hydrochloric acid tank tail gas treatment device according to claim 4, characterized in that, Multiple water washing tower tray distributors (21) are fixed along its height direction inside the water washing tower (2); a spray head (44) is fixed at the end of the water pipe (4) away from the pure water circulation tank (3) and located at the top of the inner cavity of the water washing tower (2).

6. The hydrochloric acid tank tail gas treatment device according to claim 5, characterized in that, It also includes a water tank, and the bottom side wall of the water washing tower (2) is provided with an acid overflow port, which is connected to the pure water circulation tank (3) through an acid overflow pipe; the water pipe (4) is fixed with a water outlet valve (33) on the pipeline between the water pump outlet valve (43) and the water pump (41); The water outlet of the bucket is fixedly connected to the side wall of the acid overflow pipe via the water inlet valve (31); the water inlet of the bucket is connected to the water outlet valve (33).

7. The hydrochloric acid tank tail gas treatment device according to claim 1, characterized in that, The alkali delivery pipe (7) is equipped with an alkali circulation pump (71) to pump the alkali in the alkali circulation tank (6) to the alkali washing tower (5); the alkali delivery pipe (7) is fixed with an alkali pump inlet valve (72) and an alkali pump outlet valve (73) on the pipelines of the alkali delivery pipe (7) relative to the inlet and outlet ends of the alkali circulation pump (71).

8. The hydrochloric acid tank tail gas treatment device according to claim 7, characterized in that, The alkaline washing tower (5) includes a tower body and an alkaline washing tower tray distributor (53) and a CPVC plum blossom ring packing layer (52) arranged sequentially from top to bottom inside the tower body; an alkaline washing air inlet valve (51) is fixed at one end of the air supply pipe near the alkaline washing tower (5); an alkaline spray nozzle (74) is fixed at one end of the alkaline liquid delivery pipe (7) away from the alkaline liquid circulation tank (6) and is located at the top of the inner cavity of the alkaline washing tower (5).

9. The hydrochloric acid tank tail gas treatment device according to claim 7, characterized in that, It also includes a brine reaction tank, and the bottom side wall of the alkali washing tower (5) is provided with an alkali overflow port, which is connected to the alkali circulation tank (6) through an alkali overflow pipe; the alkali delivery pipe (7) is fixed with an outlet valve (62) on the pipeline between the alkali pump outlet valve (73) and the alkali circulation pump (71); The outlet of the brine reaction tank is fixedly connected to the side wall of the alkali overflow pipe via the inlet valve (61), and the inlet of the brine reaction tank is connected to the outlet valve (62).

10. The hydrochloric acid tank tail gas treatment device according to claim 1, characterized in that, The exhaust pipe is fixed with a fan inlet valve (81) at one end near the induced draft fan (8); the exhaust pipe is fixed with an exhaust valve (54) at the other end, and the exhaust valve (54) is located on the pipeline between the exhaust pipe and the alkaline washing tower (5).

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