Gas alkali absorption device with low salt solubility

Abstract

The utility model discloses a gas alkali absorption device with low salt solubility, which comprises a stirring kettle, an absorption tower, a circulating mother liquor tank, a mother liquor discharge valve, a PH value detector and a circulating pump, the absorption tower is arranged at the top of the stirring kettle and used for spraying and absorbing tail gas entering the absorption tower, and the bottom of the stirring kettle is connected with the top of a centrifugal machine. The bottom of the centrifugal machine is connected with one end of the circulating mother liquor tank, the other end of the circulating mother liquor tank is connected with the PH value detector and the circulating pump, and the mother liquor discharge valve is connected with the PH value detector; the device can solve the technical problems that when gas such as carbon dioxide and sulfur dioxide is generated, due to the fact that the solubility of salt such as sodium sulfite and sodium bicarbonate in water is low at the normal temperature in the process that liquid alkali is used for absorption, a large amount of waste water can be generated when low-concentration alkali liquor is used for absorption, and the tower is prone to being blocked by the salt. According to the scheme, salt is subjected to solid-liquid separation through the centrifugal machine in the absorption process, absorption tower blockage is reduced, the amount of waste water is reduced, and the scheme has practicability and is suitable for application and popularization.

Description

Technical Field

[0001] This utility model belongs to the fields of chemical and pharmaceutical technology, and specifically relates to a gas alkali absorption device with low salt solubility. Background Technology

[0002] In the production fields of chemical, pharmaceutical and other industries, many chemical reactions produce gases such as carbon dioxide and sulfur dioxide. During the absorption process using liquid alkali, because the solubility of salts such as sodium sulfite and sodium bicarbonate in water is relatively low at room temperature, using low-concentration alkali solution for absorption will produce a large amount of wastewater and is prone to salt blockage of the tower.

[0003] Chinese utility model patent CN203329605U discloses a sulfur dioxide tail gas circulation absorption system, belonging to the field of sulfonation reaction equipment. It includes an absorption tower, an open liquid alkali tank, and a solid-liquid separator. A liquid alkali absorption tail gas circulation device is installed between the liquid alkali tank and the absorption tower, and a liquid alkali solid-liquid separation circulation device is installed between the liquid alkali tank and the solid-liquid separator. In this sulfur dioxide tail gas circulation absorption system, the sodium sulfite produced in the reaction in the absorption tower is returned to the liquid alkali tank through the liquid alkali absorption tail gas circulation device. Then, the liquid alkali solid-liquid separation circulation device separates the sodium sulfite precipitated in the liquid alkali tank from the absorption liquid, ensuring no wastewater discharge during the entire tail gas absorption process. The sulfur dioxide in the tail gas can also be used to prepare the industrial raw material sodium sulfite. While the aforementioned solution can improve the solid-liquid separation effect, the open liquid alkali separation tank and solid-liquid separator may cause sulfur dioxide gas to volatilize. Sulfur dioxide is a toxic gas, posing environmental pollution and personal injury risks.

[0004] Therefore, this solution provides a gas alkali absorption device with low salt solubility to solve the problems mentioned in the background art. Utility Model Content

[0005] In view of the problems mentioned in the background art, the purpose of this utility model is to provide a gas alkali absorption device with low salt solubility, which relates to a gas absorption device for sulfur dioxide, carbon dioxide and other alkaline solutions where the salt has low solubility in water after absorption, and can solve the problem in the prior art where factories need to absorb gases with low salt solubility in water after absorption by alkaline solutions such as sulfur dioxide and carbon dioxide.

[0006] To achieve the above-mentioned technical objectives, the technical solution adopted by this utility model is as follows:

[0007] A gas alkali absorption device with low salt solubility includes a stirred tank, an absorption tower, a circulating mother liquor tank, a mother liquor discharge valve, a pH meter, and a circulating pump. The absorption tower is located at the top of the stirred tank and is used to spray and absorb the tail gas entering the absorption tower. The bottom of the stirred tank is connected to the top of a centrifuge, and the bottom of the centrifuge is connected to one end of the circulating mother liquor tank. The other end of the circulating mother liquor tank is connected to the pH meter and the circulating pump. The mother liquor discharge valve is connected to the pH meter.

[0008] Further, it also includes a liquid alkali feed valve and a level gauge. The liquid alkali feed valve is located at the top of the circulating mother liquor tank, and the level gauge is located on the tank body of the circulating mother liquor tank. The liquid alkali feed valve is connected to the level gauge, and the liquid alkali feed valve is interlocked with the liquid alkali feed valve and the level gauge.

[0009] Further specified, the circulating mother liquor tank contains at least 30% of its capacity of alkaline solution, and the circulating pump circulates and absorbs the solution in the circulating mother liquor tank.

[0010] Further specifying, the mother liquor discharge valve is opened when the pH value detector detects that the pH value in the circulating mother liquor tank is 8-9.

[0011] Further specified, when the liquid level gauge is below 300ml, the mother liquor discharge valve shall be closed.

[0012] The beneficial effects of this utility model are:

[0013] 1. This utility model provides a gas alkali absorption device with low salt solubility. When the liquid alkali feed valve is opened, it is interlocked with the level gauge of the circulating mother liquor tank, and then 30% liquid alkali solution is automatically added. The circulating pump is started for circulation absorption. Then, the tail gas such as sulfur dioxide and carbon dioxide enters the absorption tower for spray absorption. The salt and absorbent produced by absorption are temporarily stored in a stirred tank. During the absorption process, centrifugation is performed to separate the solid and liquid. The precipitated salt is bagged by centrifuge. The centrifuged mother liquor continues to circulate for absorption. When the pH value of the alkali solution in the circulating mother liquor tank is between 8 and 9, the mother liquor discharge valve is opened to pump the mother liquor in the circulating mother liquor tank into the wastewater treatment. When the liquid level is below 300 mm, the discharge valve is closed, and the liquid alkali feed valve is opened and interlocked with the level gauge of the circulating mother liquor tank, and then 30% liquid alkali solution is automatically added. The cycle is repeated to realize the automatic replacement of alkali solution and tail gas absorption.

[0014] 2. This device can solve the problem of generating gases such as carbon dioxide and sulfur dioxide. During the absorption process using liquid alkali, the solubility of salts such as sodium sulfite and sodium bicarbonate in water is relatively low at room temperature. If a low concentration of alkali solution is used for absorption, a large amount of wastewater will be generated, and the technical problem of salt blockage of the absorption tower is likely to occur. In this solution, the salt is separated into solid and liquid by centrifuge during the absorption process, which reduces the blockage of the absorption tower and the amount of wastewater. This solution is practical and suitable for widespread use. Attached Figure Description

[0015] This utility model can be further illustrated by the non-limiting embodiments given in the accompanying drawings;

[0016] Figure 1 This is a schematic diagram of an embodiment of the gas alkali absorption device with low salt solubility according to the present invention.

[0017] The main component symbols are explained as follows: 1. Stirred vessel; 2. Absorption tower; 3. Centrifuge; 4. Circulating mother liquor tank; 5. Liquid alkali feed valve; 6. Level gauge; 7. Mother liquor discharge valve; 8. pH meter; 9. Circulating pump; 10. Detailed Implementation

[0018] To enable those skilled in the art to better understand this utility model, the technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments. The technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0019] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0020] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model. It should be understood that the specific embodiments described herein are merely for explaining this utility model and are not intended to limit this utility model.

[0021] It is important to know that during the production of benzoyl sulfadiazine, sulfur dioxide gas is generated during the synthesis of acyl chloride due to the decomposition and synthesis of thionyl chloride. Absorption using dilute alkaline solution would produce a large amount of wastewater. To address the problem of gas absorption in factories where the salts have low solubility in water after alkaline absorption of sulfur dioxide, carbon dioxide, etc., this invention designs a gas absorption device for these gases.

[0022] like Figure 1 As shown, this utility model discloses a gas alkali absorption device with low salt solubility, comprising a stirred tank 1, an absorption tower 2, a circulating mother liquor tank 4, a mother liquor discharge valve 8, a pH meter 9, and a circulating pump 10. The absorption tower 2 is located at the top of the stirred tank 1 and is used to spray and absorb the tail gas entering the absorption tower 2. The bottom of the stirred tank 1 is connected to the top of a centrifuge 3, and the bottom of the centrifuge 3 is connected to one end of the circulating mother liquor tank 4. The other end of the circulating mother liquor tank 4 is connected to the pH meter 9 and the circulating pump 10. The mother liquor discharge valve 8 is connected to the pH meter 9.

[0023] Preferably, it also includes a liquid alkali feed valve 6 and a level gauge 7. The liquid alkali feed valve 6 is located on the top of the circulating mother liquor tank 4, and the level gauge 7 is located on the tank body of the circulating mother liquor tank 4. The liquid alkali feed valve 6 is connected to the level gauge 7, and the liquid alkali feed valve 6 is interlocked with the liquid alkali feed valve 6 and the level gauge 7.

[0024] Preferably, at least 30% of the tank capacity of the circulating mother liquor tank 4 is filled with an alkaline solution, and the circulating pump 10 circulates and absorbs the solution in the circulating mother liquor tank 4.

[0025] Preferably, the mother liquor discharge valve 8 is opened when the pH value detector 9 detects that the pH value in the circulating mother liquor tank 4 is 8-9.

[0026] Preferably, when the level gauge 7 is below 300ml, the mother liquor discharge valve 8 is closed.

[0027] The working principle of this utility model is as follows:

[0028] This invention provides a gas alkali absorption device with low salt solubility. When the liquid alkali feed valve is opened, it is interlocked with the level gauge of the circulating mother liquor tank, and then 30% liquid alkali solution is automatically added. The circulating pump is started for circulation absorption. Then, the tail gas such as sulfur dioxide and carbon dioxide enters the absorption tower for spray absorption. The salt and absorbent produced by absorption are temporarily stored in a stirred tank. During the absorption process, centrifugation is performed to separate the solid and liquid. The precipitated salt is bagged by a centrifuge. The centrifuged mother liquor continues to circulate for absorption. When the pH value of the alkali solution in the circulating mother liquor tank is between 8 and 9, the mother liquor discharge valve is opened, and the mother liquor in the circulating mother liquor tank is pumped into the wastewater treatment. When the liquid level is below 300 mm, the discharge valve is closed, and the liquid alkali feed valve is opened and interlocked with the level gauge of the circulating mother liquor tank, and then 30% liquid alkali solution is automatically added. The cycle is repeated to realize the automatic replacement of alkali solution and tail gas absorption.

[0029] This device can solve the problem of generating gases such as carbon dioxide and sulfur dioxide. In the process of using liquid alkali absorption, because the solubility of salts such as sodium sulfite and sodium bicarbonate in water is relatively low at room temperature, if a low concentration of alkali solution is used for absorption, a large amount of wastewater will be generated, and the technical problem of salt blockage of the tower is easy to occur. This solution is practical and suitable for widespread use.

[0030] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A gas alkali absorption device with low salt solubility, characterized in that: The system includes a stirred tank (1), an absorption tower (2), a circulating mother liquor tank (4), a mother liquor discharge valve (8), a pH meter (9), and a circulating pump (10). The absorption tower (2) is located on top of the stirred tank (1) and is used to spray and absorb the exhaust gas entering the absorption tower (2). The bottom of the stirred tank (1) is connected to the top of the centrifuge (3). The bottom of the centrifuge (3) is connected to one end of the circulating mother liquor tank (4). The other end of the circulating mother liquor tank (4) is connected to the pH meter (9) and the circulating pump (10). The mother liquor discharge valve (8) is connected to the pH meter (9).

2. The gas alkali absorption device with low salt solubility according to claim 1, characterized in that: It also includes a liquid alkali feed valve (6) and a level gauge (7). The liquid alkali feed valve (6) is located on the top of the circulating mother liquor tank (4), and the level gauge (7) is located on the tank body of the circulating mother liquor tank (4). The liquid alkali feed valve (6) is connected to the level gauge (7), and the liquid alkali feed valve (6) is interlocked with the liquid alkali feed valve (6) and the level gauge (7).

3. The gas alkali absorption device with low salt solubility according to claim 2, characterized in that: At least 30% of the tank capacity of the circulating mother liquor tank (4) is added to the circulating mother liquor tank (4), and the circulating pump (10) circulates and absorbs the solution in the circulating mother liquor tank (4).

4. The gas alkali absorption device with low salt solubility according to claim 1, characterized in that: When the pH meter (9) detects that the pH value in the circulating mother liquor tank (4) is 8-9, the mother liquor discharge valve (8) is opened.

5. The gas alkali absorption device with low salt solubility according to claim 2, characterized in that: When the level gauge (7) is below 300ml, close the mother liquor discharge valve (8).

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