Acetone mixed gas washing and purifying system

Abstract

The utility model relates to the field of chemical engineering and particularly provides an acetone mixed gas washing and purifying system which comprises a washing tower, a gas inlet is formed in the lower part of the washing tower, a washing liquid inlet is formed in the upper part of the washing tower, a gas phase outlet is formed in the top of the washing tower and connected to activated carbon adsorption equipment, and a liquid outlet is formed in the bottom of the washing tower. The liquid outlet is connected to the washing liquid inlet through a washing liquid circulating pipeline and a circulating pump; a desorption gas pipeline of the activated carbon adsorption equipment is connected to a dilute acetone storage tank after passing through a condenser, and the dilute acetone storage tank is connected to a rectifying tower. According to the utility model, through the arrangement of the washing tower, acetone mixed gas is firstly introduced into the washing tower before being conveyed to the activated carbon adsorption equipment, and is washed by using a small amount of washing liquid to remove impurities such as oil, flyings, dust and the like in the gas, and the washed gas phase mainly comprises acetone and air which enter the activated carbon adsorption equipment to be adsorbed; and then analyzing and condensing to obtain dilute acetone liquid, and rectifying to separate acetone and water for recycling.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical industry and relates to an acetone mixed gas washing and purification system. Background Art

[0002] Acetate fiber tow is produced by using diacetic acid and acetone as solvents to dissolve diacetate cellulose slices into slurry, which is then made through spinning, curling and drying. During the spinning and drying process, a large amount of acetone and air mixed gas will be produced. The volatilized acetone is pumped to the acetone recovery area by negative pressure, and then reused after activated carbon adsorption and analysis, avoiding material waste and reducing pollution to the environment and harm to the human body.

[0003] During the curling and drying process of the tow, the volatilized gas contains not only acetone and air, but also oil, dust, and flying flowers. These gases enter the recovery fan and are pumped from the dryer through the sealed pipe (air duct) to the activated carbon in the adsorber for adsorption. The temperature of the dryer can reach about 100 degrees. The volatiles of the oil enter the activated carbon and occupy the gaps in the activated carbon, thereby reducing the activated carbon's adsorption capacity for acetone, making the activated carbon poisoned and unable to continue to be used. Dust and flying flowers will also pollute the activated carbon and easily cause it to burn. Summary of the invention

[0004] The utility model provides an acetone mixed gas washing and purification system, which can effectively remove oil agent and solid phase impurities in the mixed gas, prolong the service life of activated carbon, and ensure the recovery rate of acetone.

[0005] The technical scheme of the utility model is an acetone mixed gas washing and purification system, comprising a washing tower, wherein the lower part of the washing tower is provided with an air inlet, the upper part is provided with a washing liquid inlet, the top is provided with a gas phase outlet connected to an activated carbon adsorption device, the bottom is provided with a liquid discharge port, the liquid discharge port is connected to the washing liquid inlet through a washing liquid circulation pipeline and a circulation pump; the analytical gas pipeline of the activated carbon adsorption device is connected to a dilute acetone storage tank after passing through a condenser, and the dilute acetone storage tank is connected to a distillation tower.

[0006] Furthermore, a spray mechanism connected to the liquid inlet is provided in the washing tower; a packing layer is provided below the spray mechanism.

[0007] Furthermore, a demister is provided in the upper part of the washing tower, which is located between the gas phase outlet and the spray mechanism.

[0008] Furthermore, the device also includes a washing liquid storage tank, which is connected to the washing liquid inlet of the washing tower through a pipeline and a pump; the washing liquid storage tank is provided with a water adding pipeline and a sodium hydroxide adding pipeline.

[0009] Furthermore, the liquid discharge port at the bottom of the washing tower is connected to the washing liquid storage tank.

[0010] Furthermore, a stirring mechanism is provided in the washing liquid storage tank.

[0011] Furthermore, at least one packing layer is provided in the washing tower, and the packing layer includes upper and lower stainless steel meshes and packing balls filled between the two layers of stainless steel meshes.

[0012] Furthermore, two packing layers are arranged in the washing tower, the thickness of the packing layers is 10-15 cm, and the inside of the packing layers is filled with packing balls.

[0013] The utility model has the following beneficial effects:

[0014] The purification system provided by the utility model is provided with a washing tower. Before the acetone mixed gas is conveyed to the activated carbon adsorption device, it is firstly introduced into the washing tower and washed with a small amount of washing liquid to remove impurities such as oil, flying flowers and dust in the gas, wherein the oil and a small amount of acetone enter the washing liquid, and the flying flowers and dust are intercepted by the packing layer of the washing tower and are regularly cleaned; during the washing process, a small amount of acetone enters the washing liquid, the amount of the washing liquid added is controlled, and the washing liquid is recycled, and after the acetone content in the washing liquid reaches a certain concentration, the washing liquid is introduced into the rear-end distillation tower for separation treatment, and acetone, water and oil are separated; the gas phase after washing is mainly acetone and air, which enters the activated carbon adsorption device for adsorption, and then is analyzed and condensed to obtain dilute acetone liquid, and the acetone and water can be separated by distillation for reuse.

[0015] When the washing liquid from the washing tower is circulated, in addition to normal water replenishment, a sodium hydroxide addition pipeline is also provided. By adding a certain amount of sodium hydroxide to the washing liquid, the influence of acetic acid on the equipment during the treatment process can be controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the device of the utility model. DETAILED DESCRIPTION

[0017] The embodiments of the present invention will be described in detail below in conjunction with examples, but those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention.

[0018] like Figure 1As shown, the utility model provides an acetone mixed gas washing and purification system, including a washing tower 1, the lower part of the washing tower is provided with an air inlet 1-1, the upper part is provided with a washing liquid inlet 1-2, the top is provided with a gas phase outlet 1-5 connected to an activated carbon adsorption device 2, and the bottom is provided with a liquid discharge port 1-6, and the liquid discharge port is connected to the washing liquid inlet 1-2 through a washing liquid circulation pipeline and a circulation pump; the decomposition gas pipeline of the activated carbon adsorption device 2 is connected to a dilute acetone storage tank 4 after passing through a condenser, and the dilute acetone storage tank 4 is connected to a distillation tower 5. The activated carbon adsorption device 2 can be set to multiple types and used in parallel,

[0019] In a specific case, a spray mechanism 1-3 connected to the liquid inlet is provided in the washing tower 1, and a packing layer 1-4 is provided below the spray mechanism. The washing liquid is fully dispersed by the spray mechanism to improve the mass transfer efficiency between the washing liquid and the mixed gas.

[0020] In a specific case, a demister 1-7 is further provided in the upper part of the washing tower 1, which is located between the gas phase outlet 1-5 and the spray mechanism 1-3. The liquid drop content in the gas increases during the washing process. If all of it is brought into the activated carbon adsorption equipment, it will affect the adsorption performance of the activated carbon. Therefore, it is preferred to use a demister in the washing tower to remove part of the liquid droplets to extend the service life of the activated carbon and improve the adsorption efficiency.

[0021] In a specific case, the device further includes a washing liquid storage tank 3, which is connected to the washing liquid inlet of the washing tower through a pipeline and a pump; the washing liquid storage tank is provided with a water supply pipeline 3-1 and a sodium hydroxide supply pipeline 3-2. The washing liquid tank is used to temporarily store washing liquid, which can be water, and more preferably, a certain amount of sodium hydroxide is added to make it slightly alkaline, which can neutralize the acid in the washing process and avoid its impact on the equipment.

[0022] In a specific case, the drain port 1-6 at the bottom of the washing tower 1 is connected to the washing liquid storage tank 3. This facilitates the recycling of the washing liquid, and the acetone is separated and reused after reaching a certain concentration, thereby avoiding the waste of acetone.

[0023] In a specific case, a stirring mechanism is also provided in the washing liquid storage tank, so that when the sodium hydroxide solution is added, it can be mixed quickly and evenly.

[0024] In a specific case, at least one packing layer is provided in the washing tower, and the packing layer includes upper and lower stainless steel meshes and packing balls filled between the two layers of stainless steel meshes. The packing increases the contact area between the mixed gas and the washing liquid, and at the same time enriches the flying flowers and dust in the mixed gas, so that less of them enter the washing liquid.

[0025] In a specific case, two packing layers are arranged in the washing tower, the thickness of the packing layer is 10-15 cm, and the packing layer is filled with packing balls, which can be polypropylene plastic balls.

[0026] During the specific treatment, the acetone mixed gas is transported to the washing tower and washed with washing liquid (water or a mixture of water with a small amount of sodium hydroxide). It is intercepted by the packing layer, which can effectively remove the oil agent and solid impurities in the mixed gas. The gas phase then enters the activated carbon adsorption equipment for adsorption, and then is analyzed, cooled, and then distilled and separated. The recovered acetone can be reused in the acetate fiber production process.

[0027] The above embodiments are only for illustrating the technical ideas and features of the utility model, and the contents are only preferred embodiments of the utility model, but the protection scope of the utility model is not limited thereto. Within the technical scope disclosed by the utility model, equivalent changes or improvements based on the technical solution and utility model concept of the utility model should be included in the protection scope of the utility model.

Claims

1. An acetone mixed gas washing and purification system, characterized in that: The washing tower comprises a washing tower (1), wherein the lower part of the washing tower is provided with an air inlet (1-1), the upper part is provided with a washing liquid inlet (1-2), the top part is provided with a gas phase outlet (1-5) connected to an activated carbon adsorption device (2), and the bottom part is provided with a liquid discharge port (1-6), the liquid discharge port is connected to the washing liquid inlet (1-2) through a washing liquid circulation pipeline and a circulation pump; the desorption gas pipeline of the activated carbon adsorption device (2) is connected to a dilute acetone storage tank (4) after passing through a condenser, and the dilute acetone storage tank (4) is connected to a distillation tower (5).

2. The system according to claim 1, characterized in that: A spray mechanism (1-3) connected to a liquid inlet is provided in the washing tower (1); a packing layer (1-4) is provided below the spray mechanism.

3. The system according to claim 2, characterized in that: A demister (1-7) is also provided in the upper part of the washing tower (1), and is located between the gas phase outlet (1-5) and the spray mechanism (1-3).

4. The system according to any one of claims 1 to 3, characterized in that: The system also includes a washing liquid storage tank (3), which is connected to the washing liquid inlet of the washing tower through a pipeline and a pump; the washing liquid storage tank is provided with a water adding pipeline (3-1) and a sodium hydroxide adding pipeline (3-2).

5. The system according to claim 4, characterized in that: The liquid discharge port (1-6) at the bottom of the washing tower (1) is connected to the washing liquid storage tank (3).

6. The system according to claim 4, characterized in that: A stirring mechanism is also provided in the washing liquid storage tank.

7. The system according to claim 1, characterized in that: At least one packing layer is arranged in the washing tower, and the packing layer comprises upper and lower stainless steel meshes and packing balls filled between the two layers of stainless steel meshes.

8. The system according to claim 7, characterized in that: There are two layers of packing in the washing tower. The thickness of the packing layer is 10~15cm, and the inside of the packing layer is filled with packing balls.

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