Vinyl chloride waste incineration flue gas washing tower

Abstract

The utility model relates to the technical field of vinyl chloride production equipment, in particular to a vinyl chloride waste incineration flue gas washing tower which comprises a base and a neutralizing tower, the neutralizing tower comprises a gas inlet cylinder and a neutralizing part which are communicated, a gas inlet pipe is arranged in the gas inlet cylinder, and a gas outlet pipe is arranged in the neutralizing part. The neutralization part comprises a first filler part, a first liquid distributor, a bubble cap tray, a partition part, a second filler part, a second liquid distributor, a demister group, a demister cleaning device and an end socket which are sequentially arranged from bottom to top, and an air outlet is formed in the top of the end socket. According to the utility model, the residence time of flue gas in the tower is prolonged by adjusting the size proportion of the height and the pipe diameter of the neutralization tower, so that the neutralization reaction of the flue gas and alkali liquor is more thorough; the nozzle group for uniformly atomizing and spraying the alkali liquor is arranged, so that the contact area of the alkali liquor and the flue gas is increased; by arranging the bubble cap tray, flue gas is dispersed into fine bubbles in alkali liquor, and the contact area of the flue gas and the alkali liquor is increased, so that the neutralization efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of vinyl chloride production equipment, in particular to a vinyl chloride waste incineration flue gas washing tower. Background Art

[0002] In the production of vinyl chloride, it is mainly divided into ethylene oxychlorination reaction and direct chlorination reaction to produce ethylene dichloride, and then ethylene dichloride is cracked to produce vinyl chloride and HCl. During the process reaction, certain side reactions will occur, producing unwanted by-products.

[0003] The ethylene oxychlorination process is a method used to produce vinyl chloride, primarily by reacting ethylene, chlorine, and oxygen to produce ethylene dichloride. The ethylene oxychlorination process produces three particularly undesirable byproducts: chloral (CCl3CHO), trichloroethylene (C2HCl3), and tetrachloroethylene (C2CL4). The reaction equations are as follows:

[0004] C2H2+ 3HCl + 3 / 2O2→ CCl3CHO + 2H2O

[0005] C2H2+ 3HCl + O2→ C2HCl3+ 2H2O

[0006] C2H2+ 4HCl + 3 / 2O2→ C2CL4+ 3H2O

[0007] Direct chlorination reaction: Chlorine gas is used to react directly with ethylamine to produce dichloroethane. The reaction is generally carried out under heating conditions, and the reaction temperature is generally between 100 and 150°C. This method has the advantages of simple operation and easy availability of raw materials, but the yield is low, and the reactant ethyl chloride is difficult to separate and purify. The reaction equation is as follows:

[0008] CH3CH2Cl + CL2→ C2H4Cl2+ HCL (direct reaction to form dichloroethane)

[0009] C2H4Cl2→ C2H3Cl2+ HCl (ethylene dichloride cracking to produce vinyl chloride)

[0010] In the direct chlorination reaction, chlorinated by-products will be produced. The reaction equation is as follows:

[0011] C2H4Cl2→ 2H2 + 2HCl + 2C

[0012] C2H3Cl → C2H2 + HCl

[0013] C2H3Cl + HCl → CH3CHCl2

[0014] nC2H3Cl → (-CH2CHCl-)n

[0015] Except for a small amount of the above-mentioned by-products that are converted into required substances through special treatment, most of the by-products must be separated from the products through distillation and steam stripping, and then sent to gas, liquid and solid incineration equipment for waste combustion treatment.

[0016] In the waste incineration device, after the by-products are burned, the liquid part is converted into 18% hydrochloric acid. The scrubber is an indispensable part of the gas treatment device. The flue gas can only be discharged into the atmosphere after it has been treated and qualified by the scrubber.

[0017] In the prior art, since the flue gas generated by waste combustion contains a certain amount of HCl, a 10% NaOH solution is used for washing. The alkaline washing and neutralization reaction process is as follows:

[0018] NaOH + HCl = NaCl + H2O

[0019] Na2CO3+ CL2= NaCL + NaCLO + CO2

[0020] Flue gas after scrubbing contains N2, O2, CO2, and H2O. Environmentally polluting HCl and Cl2 must be reduced to acceptable levels. Inadequate scrubbing can leave residual HCl in the flue gas. When the flue gas enters the next process, the temperature drops and condenses. The escaping HCl can form a certain amount of HCl solution, causing corrosion to the equipment. Increasing the concentration and flow rate of the liquid caustic soda cannot solve this problem. Instead, salt buildup can form on the scrubber's inner walls and packing, making cleaning difficult during scrubber maintenance.

[0021] Therefore, there is an urgent need for a flue gas scrubber for incinerating vinyl chloride waste to scrub the flue gas more thoroughly. Utility Model Content

[0022] In order to solve the above technical problems, the utility model provides a flue gas washing tower for incineration of vinyl chloride waste, which can better wash the flue gas by increasing the contact area and reaction time between the alkaline solution and the flue gas.

[0023] The utility model provides the following specific technical solutions:

[0024] The utility model discloses a flue gas washing tower for incineration of vinyl chloride waste, comprising a base, a neutralization tower installed on the top of the base, the neutralization tower comprising an air intake cylinder and a neutralization part which are connected and arranged, an air intake pipe being arranged inside the air intake cylinder, and the neutralization part comprising a first filling part, a first liquid distributor, a bubble cap tray, a partition part, a second filling part, a second liquid distributor, a demister group, a demister cleaning device and a head which are arranged in sequence from the bottom to the top, and an air outlet being arranged on the top of the head.

[0025] Preferably, the ratio of the height of the neutralization tower to its diameter is 6 to 8.5: 1. By adjusting the ratio of the height of the neutralization tower to its diameter and increasing the height of the neutralization tower, the time the flue gas stays in the tower can be increased, making the neutralization reaction between the flue gas and the alkali solution more thorough.

[0026] Preferably, the first liquid distributor and the second liquid distributor each include a liquid inlet pipe for introducing alkali solution, and the liquid inlet pipe is connected to at least one layer of nozzle groups for uniformly atomizing the alkali solution. The nozzle group can achieve uniform atomization and spraying of the 10% NaOH solution, thereby increasing the contact area between the alkali solution and the flue gas, thereby better scrubbing the flue gas.

[0027] Preferably, each layer of nozzle groups is provided with 19 nozzles.

[0028] Preferably, the nozzle corresponding to the first liquid distributor is set to have a flow rate of 90 to 95 liters / minute under a pressure of 0.15 MPa; a flow rate of 125 to 130 liters / minute under a pressure of 0.3 MPa; and a spray angle of 90 degrees.

[0029] Preferably, the nozzle corresponding to the second liquid distributor is set to have a flow rate of 75 to 85 liters / minute at a pressure of 0.07 MPa; a flow rate of 115 to 120 liters / minute at a pressure of 0.15 MPa; and a spray angle of 90 degrees.

[0030] Preferably, the bubble cap tray includes a liquid addition port and a drain port, both of which are provided with 90-degree elbows. The bubble cap tray disperses the flue gas into fine bubbles in the alkali solution ejected from the first liquid distributor 7, significantly increasing the contact area between the flue gas and the alkali solution, thereby improving the neutralization efficiency. It can also maintain high efficiency over a wide range of load variations, making it adaptable to different operating conditions, such as flue gas volume fluctuations.

[0031] Preferably, the distance between the bubble cap tray and the top of the first packing part is 1800 to 2000 mm.

[0032] Preferably, the demister assembly includes a bottom-mounted baffle demister located at the top of the demister cleaning device and a top-mounted baffle demister located at the bottom of the demister cleaning device. The bottom-mounted baffle demister and the top-mounted baffle demister arranged in two layers can effectively remove HCl liquid mist entrained in the flue gas.

[0033] Preferably, the tower wall of the neutralization tower includes a tower body lining layer, a tower body reinforcement layer and a tower body outer shell layer arranged in sequence from the inside to the outside, wherein the tower body lining layer is formed by resin injection molding and the tower body reinforcement layer is formed by resin winding.

[0034] The utility model has the following technical effects:

[0035] 1. The utility model increases the height of the neutralization tower by adjusting the size ratio of the neutralization tower height to its diameter, thereby increasing the time the flue gas stays in the tower and making the neutralization reaction between the flue gas and the alkali solution more thorough;

[0036] 2. The nozzle group corresponding to the first liquid distributor and the nozzle group corresponding to the second liquid distributor in the present invention can achieve uniform atomization spraying of the alkali solution, increase the contact area between the alkali solution and the flue gas, and can better wash the flue gas;

[0037] 3. The utility model provides a bubble tray so that the flue gas is dispersed into fine bubbles in the alkali solution, which greatly increases the contact area between the flue gas and the alkali solution, thereby improving the neutralization efficiency and maintaining high efficiency within a larger load variation range. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural diagram of the utility model;

[0039] Figure 2 This is a schematic structural diagram of the nozzle group of the first liquid distributor or the second liquid distributor in the present invention;

[0040] Figure 3 It is a structural schematic diagram of the neutralization tower body wall in the utility model.

[0041] In the figure: 1. base, 2. air inlet cylinder, 3. air inlet pipe, 4. packing support plate, 41. bed restriction plate, 5. neutralization tower, 51. tower body inner lining, 52. tower body reinforcement layer, 53. tower body outer shell, 6. first packing part, 7. first liquid distributor, 8. partition part, 9. demister cleaning device, 10. head, 11. air outlet, 12. demister group, 121. bottom-mounted baffle demister, 122. top-mounted baffle demister, 13. second liquid distributor, 14. second packing part, 15. bubble cap tray, 16. nozzle. DETAILED DESCRIPTION

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0043] In the vinyl chloride production process, it is mainly divided into ethylene oxychlorination reaction (ethylene oxychlorination is a method for producing vinyl chloride, mainly through the reaction of ethylene, chlorine and oxygen to produce ethylene dichloride) and direct chlorination reaction to produce ethylene dichloride, and then the ethylene dichloride is cracked to produce vinyl chloride and HCl. Certain side reactions will occur during the process reaction, producing unwanted by-products.

[0044] While a small amount of these byproducts undergoes special treatment to transform them into desired substances, the majority are separated from the products through distillation and stripping before being sent to gas, liquid, and solid incineration units for waste combustion. In the waste incineration unit, after the byproducts are burned, the liquid portion is converted into 18% hydrochloric acid. The gas is then treated by process equipment and released into the atmosphere after passing the required standards. The scrubber, an integral component of the gas treatment unit, plays a crucial role. Because the flue gas from waste combustion contains a certain amount of HCl, a 10% NaOH solution is used for scrubbing. After scrubbing, the environmentally polluting HCl and Cl₂ in the flue gas must be reduced to acceptable levels.

[0045] A conventional flue gas scrubber for vinyl chloride waste incineration primarily consists of, from bottom to top, an outlet, a bottom-mounted baffled demister, a demister cleaning device, a top-mounted baffled demister, two layers of liquid inlet pipes, a tubular liquid distributor, a bed restriction plate, Taylor rosette packing, corrugated packing support plates, packing supports separated by partitions between the two layers, and an air inlet. The flue gas generated by the waste combustion, after preliminary treatment, enters the alkaline scrubber from the bottom side of the scrubber. A 10% concentration of NaOH solution enters the scrubber from the two liquid inlet pipes above the scrubber and flows downward by gravity, creating countercurrent scrubbing with the flue gas.

[0046] like Figure 1 As shown, in order to more fully wash the residual hydrogen chloride in the flue gas, the utility model discloses a vinyl chloride waste incineration flue gas washing tower, including a base 1, a neutralization tower 5 is installed on the top of the base 1, the neutralization tower 5 includes an air intake cylinder 2 and a neutralization part which are connected and arranged, an air intake pipe 3 is arranged inside the air intake cylinder 2, and the neutralization part includes a first packing part 6, a first liquid distributor 7, a bubble tower plate 15, a partition part 8, a second packing part 14, a second liquid distributor 13, a demister group 12, a demister cleaning device 9 and a head 10 which are arranged in sequence from bottom to top, and an air outlet 11 is provided on the top of the head.

[0047] The head 10 is a standard elliptical head.

[0048] In the embodiment disclosed in the present invention, the height-to-diameter ratio of the neutralization tower 5 is 6 to 8.5:1. By adjusting the height-to-diameter ratio of the neutralization tower 5 and increasing the height of the neutralization tower 5, the time the flue gas stays in the tower can be increased, resulting in a more thorough neutralization reaction between the flue gas and the alkali solution.

[0049] like Figure 2 As shown, in the embodiment disclosed in the present invention, the first liquid distributor 7 and the second liquid distributor 13 each include a liquid inlet pipe for introducing alkali solution. The liquid inlet pipe is connected to at least one layer of nozzle groups for uniformly atomizing the alkali solution, and each layer of nozzle groups is provided with 19 nozzles 16. The alkali solution is a 10% concentration NaOH solution.

[0050] The nozzle corresponding to the first liquid distributor 7 is configured to provide a flow rate of 90-95 liters / minute at a pressure of 0.15 MPa and a flow rate of 125-130 liters / minute at a pressure of 0.3 MPa. The spray angle is 90 degrees. In the embodiment disclosed herein, the nozzle corresponding to the first liquid distributor 7 can be selected as SJ 1 / 2-PP 90 164.

[0051] Furthermore, the nozzle corresponding to the second liquid distributor 13 is configured to provide a flow rate of 75-85 liters / minute at a pressure of 0.07 MPa and a flow rate of 115-120 liters / minute at a pressure of 0.15 MPa, with a spray angle of 90 degrees. In the embodiment disclosed herein, the nozzle model corresponding to the second liquid distributor 13 can be selected as SJ 3 / 4-PP 90 210.

[0052] The nozzles corresponding to the first liquid distributor 7 and the nozzles corresponding to the second liquid distributor 13 can both achieve uniform atomization and spraying of the 10% NaOH solution, thereby increasing the contact area between the alkali solution and the flue gas and better washing the flue gas.

[0053] In the embodiment disclosed in the present utility model, the bubble cap tray 15 includes a liquid adding port and a draining port, and both the liquid adding port and the draining port are provided with a 90-degree elbow.

[0054] The first liquid distributor 7 is positioned between the bubble-cap tray 15 and the top of the first packing section 6, with the distance between the bubble-cap tray 15 and the top of the first packing section 6 being 1800 to 2000 mm. This design allows the bubble-cap tray 15 to disperse the flue gas into fine bubbles in the lye sprayed from the first liquid distributor 7, significantly increasing the contact area between the flue gas and the lye, thereby improving neutralization efficiency. It also maintains high efficiency over a wide range of load variations, making it adaptable to varying operating conditions, such as flue gas volume fluctuations.

[0055] In the embodiment disclosed in the present invention, the demister assembly includes a bottom-mounted baffle demister 121 located at the top of the demister cleaning device 9 and a top-mounted baffle demister 122 located at the bottom of the demister cleaning device 9. The bottom-mounted baffle demister 121 and the top-mounted baffle demister 122 arranged in two layers can effectively remove HCl liquid mist entrained in the flue gas.

[0056] like Figure 3 As shown, in the embodiment disclosed in the present invention, the tower wall of the neutralization tower 5 includes a tower body lining layer 51, a tower body reinforcement layer 52 and a tower body outer shell layer 53 which are sequentially arranged from the inside to the outside.

[0057] The tower body lining 51 is injection molded from DEAKANE-411 resin, and the tower body reinforcement layer 52 is wound from A400 resin. The resin content of the tower body lining 51 is ≥80% and the thickness is ≥6.5 mm.

[0058] In the disclosed embodiment of the present invention, Taylor rosette packing is provided in both the first packing section 6 and the second packing section 14. Taylor rosette packing has the characteristics of high porosity, low clogging resistance, high flux, and low resistance. Because the gaps between these packings can retain a high amount of liquid, the liquid can be retained in the tower for a longer time, thereby increasing the contact time between gas and liquid and improving efficiency.

[0059] Furthermore, a packing support plate 4 and a bed limiting plate 41 are provided on the first packing part 6 and the second packing part 14. The packing support plate 4 is used to support the packing of the first packing part 6 and the second packing part 14, and the bed limiting plate 41 is used to compress the packing of the first packing part 6 and the second packing part 14.

[0060] The working principle of this utility model is:

[0061] The flue gas generated after the combustion of the waste enters the air intake cylinder 2 from the air intake pipe 3 after preliminary treatment, and then enters the neutralization tower 5. The 10% concentration NaOH solution enters the corresponding nozzle group from the liquid inlet pipes of the first liquid distributor 7 and the second liquid distributor 13 for spray atomization. The 10% concentration NaOH solution after spraying and atomizing flows downward under the action of its own gravity.

[0062] After the flue gas flows upward through the Taylor rosette packing in the first packing part 6, it undergoes the first convection washing with the atomized NaOH solution sprayed by the nozzle group of the first liquid distributor 7. After the first convection washing, the flue gas continues to flow upward to the bubble tower plate 15, and the flue gas is dispersed into fine bubbles in the alkali solution in the bubble tower plate 15, which increases the contact area between the flue gas and the alkali solution, and undergoes the second convection washing. After the second convection washing, the flue gas continues to flow upward through the Taylor rosette packing in the second packing part 14, and undergoes the third convection washing with the atomized NaOH solution sprayed by the nozzle group of the second liquid distributor 13. After the third convection washing, the flue gas continues to flow upward to the demister group 12, and after the demisting treatment, enters the head 10, and flows out of the neutralization tower 5 through the air outlet 11 to enter the next process treatment.

[0063] For ordinary technicians in this field, based on the teachings of this utility model, without departing from the principles and spirit of this utility model, changes, modifications, substitutions and variations made to the implementation methods are still within the scope of protection of this utility model.

Claims

1. A flue gas scrubber for incineration of vinyl chloride waste, comprising a base (1), a neutralization tower (5) mounted on the top of the base (1), the neutralization tower (5) comprising an air intake cylinder (2) and a neutralization portion connected to each other, an air intake pipe (3) being arranged inside the air intake cylinder (2), characterized in that: The neutralization section comprises a first packing section (6), a first liquid distributor (7), a bubble cap tray (15), a partition section (8), a second packing section (14), a second liquid distributor (13), a demister group (12), a demister cleaning device (9) and a head (10) which are arranged in sequence from bottom to top, and an air outlet (11) is provided at the top of the head.

2. A vinyl chloride waste incineration flue gas scrubber according to claim 1, characterized in that: The ratio of the height of the neutralization tower (5) to its diameter is 6 to 8.5:

1.

3. The vinyl chloride waste incineration flue gas scrubber according to claim 1, characterized in that: The first liquid distributor (7) and the second liquid distributor (13) both comprise a liquid inlet pipe, the liquid inlet pipe being used to introduce alkali solution, and the liquid inlet pipe being connected to at least one layer of nozzle groups for uniformly atomizing the alkali solution.

4. A vinyl chloride waste incineration flue gas scrubber according to claim 3, characterized in that: Each layer of nozzle group is provided with 19 nozzles (16).

5. The vinyl chloride waste incineration flue gas scrubber according to claim 3, characterized in that: The nozzle corresponding to the first liquid distributor (7) is configured as follows: At 0.15MPa pressure, the flow rate is 90-95L / min; At a pressure of 0.3 MPa, the flow rate is 125-130 liters / minute; The spray angle is 90 degrees.

6. The vinyl chloride waste incineration flue gas scrubber according to claim 3, characterized in that: The nozzle corresponding to the second liquid distributor (13) is set as follows: At a pressure of 0.07 MPa, the flow rate is 75 to 85 liters per minute; At a pressure of 0.15 MPa, the flow rate is 115-120 liters / minute; The spray angle is 90 degrees.

7. The vinyl chloride waste incineration flue gas scrubber according to claim 1, characterized in that: The bubble cap tray (15) comprises a liquid adding port and a draining port, and both the liquid adding port and the draining port are provided with 90-degree elbows.

8. The vinyl chloride waste incineration flue gas scrubber according to claim 7, characterized in that: The distance between the bubble cap tray (15) and the top of the first packing part (6) is 1800 to 2000 mm.

9. The vinyl chloride waste incineration flue gas scrubber according to claim 1, characterized in that: The demister group (12) comprises a bottom-mounted baffle demister (121) located at the top of the demister cleaning device (9) and a top-mounted baffle demister (122) located at the bottom of the demister cleaning device (9).

10. The vinyl chloride waste incineration flue gas scrubber according to claim 1, characterized in that: The tower body wall of the neutralization tower (5) comprises a tower body lining layer (51), a tower body reinforcement layer (52) and a tower body outer shell layer (53) arranged in sequence from the inside to the outside. The tower body inner lining layer (51) is formed by resin injection molding, and the tower body reinforcement layer (52) is formed by resin winding.

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