Tail gas treatment device for acetonitrile production

Abstract

The utility model discloses a tail gas treatment device for acetonitrile production, which comprises a tail gas absorption tower, the tail gas absorption tower comprises a first adsorption cavity, the bottom of the first adsorption cavity is provided with a first tail gas inlet pipe, the upper end in the first adsorption cavity is provided with a concentric-square-shaped bent pipe, and the lower end of the concentric-square-shaped bent pipe is uniformly provided with a plurality of nozzles; a first water blocking device and a second water blocking device which are arranged up and down are arranged in the middle of the first adsorption cavity, liquid smoothing plates which are obliquely arranged at intervals are arranged in the first water blocking device and the second water blocking device, and the inclination directions of the liquid smoothing plates of the first water blocking device and the liquid smoothing plates of the second water blocking device are opposite. The contact time of the tail gas and the absorption liquid can be prolonged, the tail gas and the absorption liquid are fully fused, and the tail gas treatment effect is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a tail gas treatment device for acetonitrile production belongs to tail gas treatment technology field for acetonitrile production. BACKGROUND

[0002] Acetonitrile is an organic compound, is a colorless transparent liquid, has excellent solvent performance, can dissolve a variety of organic, inorganic and gaseous substances, and is infinitely soluble with water and alcohol, acetonitrile can occur typical nitrile reaction, and be used to prepare many typical nitrogen-containing compounds, is an important organic intermediate, acetonitrile is used in recent years for thin layer chromatography, paper chromatography, spectrum and polarographic analysis organic modifier and solvent, because high-purity acetonitrile does not absorb ultraviolet rays at 200nm~400nm, therefore, an application being developed is used as the solvent of high performance liquid chromatography HPLC, can make the analysis sensitivity up to 10-9 level, acetonitrile is a widely used solvent, mainly as the solvent of extraction distillation method, separates butadiene from C4 hydrocarbons, acetonitrile is also used for the separation of other hydrocarbons, such as separating propylene, isoprene and methyl acetylene from hydrocarbon fractions.

[0003] In the synthesis process of acetonitrile, waste gas containing acetonitrile is generated. For example, when acetonitrile is synthesized by using acrylonitrile as raw material, the tail gas after reaction contains unreacted acrylonitrile, acetonitrile and by-products. In the prior art, the conventional waste gas treatment is generally carried out by absorbing the waste gas in an adsorption tower. However, in actual application, the amount of waste gas discharged in acetonitrile production is large, and the contact time of the large-flow waste gas with the absorption solvent is short, so that the waste gas cannot fully react with the absorption solvent, resulting in unqualified waste discharge.

[0004] From the above, it can be seen that the prior art has obvious inconvenience and defects in actual use, so it is necessary to improve. UTILITY MODEL CONTENT

[0005] The utility model provides a tail gas treatment device for acetonitrile production for the deficiency in the background art, can increase the contact time of tail gas and absorption liquid, makes tail gas and absorption fully blend, improves the treatment effect of tail gas.

[0006] To solve the above technical problems, the utility model adopts the following technical scheme:

[0007] A tail gas treatment device for acetonitrile production, including tail gas absorption tower, the tail gas absorption tower includes first adsorption cavity, the bottom of first adsorption cavity is equipped with first tail gas inlet pipe, the upper end in first adsorption cavity is equipped with the serpentine bend, and the lower end of serpentine bend is evenly arranged with a plurality of spray heads;

[0008] The first water stopper and the second water stopper are arranged in an up-down manner, and the first water stopper and the second water stopper are internally provided with sequentially arranged liquid following plates.

[0009] Further, the first adsorption cavity is internally provided with a water baffle which is arranged at the lower side of the U-shaped bend pipe.

[0010] Further, the tail gas absorption tower further comprises a second adsorption cavity, the bottom of the second adsorption cavity is provided with a second tail gas inlet pipe, the top of the second adsorption cavity is provided with a second U-shaped bend pipe, the lower end of the second U-shaped bend pipe is uniformly provided with a plurality of spray heads, and the top of the first adsorption cavity is connected with the second tail gas inlet pipe through a first exhaust pipe.

[0011] Further, the second adsorption cavity is internally provided with a water baffle, a first water stopper and a second water stopper which are sequentially arranged from top to bottom at the lower side of the second U-shaped bend pipe.

[0012] Further, the first adsorption cavity and the second adsorption cavity are provided with a spacing plate.

[0013] Further, the bottom of the first adsorption cavity and the bottom of the second adsorption cavity are respectively connected with an absorption liquid storage tank through pipelines, the absorption liquid storage tank is connected with the first U-shaped bend pipe through a liquid inlet pipe, and a water pump is arranged on the pipeline section of the liquid inlet pipe.

[0014] Further, the tail gas absorption tower further comprises a purification tank, and the purification tank is internally provided with an active carbon filter and a plurality of UV lamp tubes.

[0015] Further, the top of the second adsorption cavity is connected with the purification tank through a second exhaust pipe, and a fan is arranged on the pipeline section of the second exhaust pipe.

[0016] Compared with the prior art, the tail gas absorption tower has the following advantages after the above technical scheme is adopted.

[0017] After the tail gas is adsorbed in the first adsorption cavity, the tail gas is connected with the bottom of the second adsorption cavity through the first exhaust pipe, the tail gas is further adsorbed in the second adsorption cavity, and the treatment effect of the tail gas is greatly enhanced after the tail gas sequentially flows through the first adsorption cavity and the second adsorption cavity.

[0018] The tail gas absorption tower will be described in detail below in combination with the drawings and embodiments. DRAWINGS

[0019] Figure 1 is a structural schematic view of the tail gas absorption tower;

[0020] Figure 2 is Figure 1 is a sectional view along A-A;

[0021] Figure 3 is the structure diagram in the purification tank.

[0022] In the figure, 1-first adsorption cavity, 2-second adsorption cavity, 3-intermediate plate, 4-first water stop, 5-second water stop, 6-water baffle, 7-liquid inlet pipe, 8-first return bend, 9-second return bend, 10-water pump, 11-absorption liquid storage tank, 12-fan, 13-purification tank, 14-activated carbon filter, 15-UV lamp, 16-first tail gas inlet pipe, 17-second tail gas inlet pipe, 18-first exhaust pipe, 19-second exhaust pipe. DETAILED DESCRIPTION

[0023] In order to have a clearer understanding of the technical features, purposes and effects of the utility model, the specific implementation mode of the utility model will be explained by referring to the drawings.

[0024] As Figure 1 shown, the utility model provides a tail gas treatment device for acetonitrile production, including tail gas absorption tower, the tail gas absorption tower includes first adsorption cavity 1, the bottom of first adsorption cavity 1 is equipped with first tail gas inlet pipe 16, the upper end in first adsorption cavity 1 is equipped with first return bend 8, the lower end of first return bend 8 is evenly arranged with multiple spray heads;

[0025] The intermediate position of first adsorption cavity 1 is equipped with first water stop 4 and second water stop 5 arranged in an up-down manner, the inside of first water stop 4 and second water stop 5 is equipped with liquid following plate arranged in an inclined manner, and the inclined directions of the liquid following plate of first water stop 4 and second water stop 5 are opposite.

[0026] The tail gas produced in the production process of acetonitrile enters first adsorption cavity 1 from first tail gas inlet pipe 16, fills absorption liquid into first return bend 8, the spray head at the top is installed at the lower end of first return bend 8, so that the absorption liquid can be evenly sprayed into first adsorption cavity 1, first water stop 4 and second water stop 5 slow down the downflow speed of absorption liquid, the absorption liquid is attached to the liquid following plate, the contact area of tail gas and absorption liquid is increased, and the inclined arrangement of the liquid following plate lengthens the flow path of tail gas, so that the tail gas can be fully contacted with the absorption liquid, and the tail gas adsorption effect is good.

[0027] The lower side of first adsorption cavity 1 is installed with water baffle 6 at the lower side of first return bend 8, and the water baffle 6 is evenly distributed with multiple water leakage holes. The absorption liquid falls on the water baffle 6, plays the role of distributing liquid flow, at the same time, slows down the falling speed of liquid droplets sprayed by the spray head, and further enhances the contact of tail gas and absorption liquid.

[0028] The tail gas absorption tower further comprises a second adsorption cavity 2, the bottom of the second adsorption cavity 2 is provided with a second tail gas inlet pipe 17, and the top of the second adsorption cavity 2 is provided with a second return-shaped bend pipe 9, the lower end of the second return-shaped bend pipe 9 is uniformly provided with a plurality of spray heads, and the top of the first adsorption cavity 1 is connected with the second tail gas inlet pipe 17 in a communication mode through a first exhaust pipe 18.

[0029] The lower side of the second return-shaped bend pipe 9 in the second adsorption cavity 2 is sequentially provided with a water baffle 6, a first water stop 4 and a second water stop 5 from top to bottom.

[0030] The first adsorption cavity 1 and the second adsorption cavity 2 are provided with a spacing plate 3.

[0031] The bottom of the first adsorption cavity 1 and the bottom of the second adsorption cavity 2 are connected with an absorption liquid storage tank 11 in a communication mode through pipelines, the absorption liquid storage tank 11 is connected with the first return-shaped bend pipe 8 in a communication mode through a liquid inlet pipe 7, and a water pump 10 is arranged on the pipe section of the liquid inlet pipe 7.

[0032] The utility model further comprises a purification tank 13, and the purification tank 13 is internally provided with an activated carbon filter 14 and a plurality of UV lamp tubes 15.

[0033] The top of the second adsorption cavity 2 is connected with the purification tank 13 in a communication mode through a second exhaust pipe 19, and a fan 12 is arranged on the pipe section of the second exhaust pipe 19.

[0034] After the tail gas is adsorbed in the first adsorption cavity 1, the tail gas is connected with the bottom of the second adsorption cavity 2 in a communication mode through the first exhaust pipe 18, the tail gas is further adsorbed in the second adsorption cavity 2, the tail gas sequentially flows through the first adsorption cavity 1 and the second adsorption cavity 2, the treatment effect of the tail gas is greatly enhanced, then the tail gas is discharged into the purification tank 13 through the second exhaust pipe 19, the tail gas is further deodorized in the purification tank 13, residual organic gas is further decomposed, and the treatment effect of the tail gas is improved.

[0035] The above is an example of the best implementation mode of the utility model, wherein the parts not described in detail are all the common knowledge of the ordinary skilled in the art. The protection scope of the utility model is subject to the content of the claims, and any equivalent transformation based on the technical inspiration of the utility model is also within the protection scope of the utility model.

Claims

1. An off-gas treatment device for acetonitrile production, characterized by: The exhaust absorption tower comprises a first adsorption cavity (1), the bottom of the first adsorption cavity (1) is provided with a first exhaust inlet pipe (16), the upper end in the first adsorption cavity (1) is provided with a meandering bend pipe (8), and the lower end of the meandering bend pipe (8) is uniformly provided with a plurality of spray heads. A first water stopper (4) and a second water stopper (5) are arranged in the middle of the first adsorption cavity (1) in an up-down arrangement, the first water stopper (4) and the second water stopper (5) are both internally provided with sequentially inclined liquid following plates, and the inclined directions of the liquid following plates of the first water stopper (4) and the second water stopper (5) are opposite.

2. The tail gas treatment device for acetonitrile production according to claim 1, characterized by: A water baffle (6) is arranged at the lower side of the meandering bend pipe (8) in the first adsorption cavity (1), and the water baffle (6) is uniformly provided with a plurality of water leakage holes.

3. The tail gas treatment device for acetonitrile production according to claim 2, characterized by: The exhaust absorption tower further comprises a second adsorption cavity (2), the bottom of the second adsorption cavity (2) is provided with a second exhaust inlet pipe (17), the top of the second adsorption cavity (2) is provided with a second meandering bend pipe (9), the lower end of the second meandering bend pipe (9) is uniformly provided with a plurality of spray heads, and the top of the first adsorption cavity (1) is connected with the second exhaust inlet pipe (17) through a first exhaust pipe (18).

4. The tail gas treatment device for acetonitrile production according to claim 3, characterized by: The lower side of the second meandering bend pipe (9) in the second adsorption cavity (2) is sequentially provided with the water baffle (6), the first water stopper (4) and the second water stopper (5) from top to bottom.

5. The tail gas treatment device for acetonitrile production according to claim 4, characterized by: The first adsorption cavity (1) and the second adsorption cavity (2) are provided with a spacing plate (3) therebetween.

6. The tail gas treatment device for acetonitrile production according to claim 3, characterized by: The bottoms of the first adsorption cavity (1) and the second adsorption cavity (2) are respectively connected with an absorption liquid storage tank (11) through pipelines, the absorption liquid storage tank (11) is connected with the first meandering bend pipe (8) through a liquid inlet pipe (7), and a water pump (10) is arranged on the pipe section of the liquid inlet pipe (7).

7. The tail gas treatment device for acetonitrile production according to claim 3, characterized by: The exhaust absorption tower further comprises a purification tank (13), the purification tank (13) is internally provided with an activated carbon filter (14) and a plurality of UV lamp tubes (15).

8. The tail gas treatment device for acetonitrile production according to claim 7, characterized by: The top of the second adsorption cavity (2) is connected with the purification tank (13) through a second exhaust pipe (19), and a fan (12) is arranged on the pipe section of the second exhaust pipe (19).

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