Recovery system of dichloromethane waste gas

Abstract

The utility model relates to the technical field of dichloromethane gas recovery, in particular to a dichloromethane waste gas recovery system which is characterized in that dichloromethane waste gas enters a flame arrester, the gas phase outlet end of a filter is connected with the gas phase inlet end of a cooling and heating combiner, the gas phase outlet end of the cooling and heating combiner is connected with the inlet end of a first fan, and the inlet end of the first fan is connected with the outlet end of a second fan; the outlet end of the first fan is connected with the gas phase inlet end of the first-stage adsorption tank, the gas phase outlet end of the first-stage adsorption tank is connected with the gas phase inlet end of the second-stage adsorption tank, the gas phase outlet end of the second-stage adsorption tank is connected with the inlet end of the demister, and the outlet end of the demister is communicated with the external; according to the utility model, the dichloromethane is recovered by adopting a two-stage adsorption technical scheme, the cooling and heating combiner is arranged, impurities are removed by cooling, the temperature of the dichloromethane is raised to 30 DEG C, and then the dichloromethane enters the first-stage adsorption tank and the second-stage adsorption tank through the first fan for adsorption, so that the removal rate of the dichloromethane is up to more than 99.9%, and the removal rate of the dichloromethane is up to more than 99.9%. Therefore, standard emission is realized.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of methylene chloride gas recovery, especially a methylene chloride waste gas recovery system. BACKGROUND

[0002] Methylene chloride is a commonly used organic solvent, which is widely used in the fields of medicine, film, industrial refrigeration, industrial extraction, etc. The conventional methylene chloride-containing waste gas recovery technology mainly includes condensation method, incineration method, etc.

[0003] The condensation method is simple in process and convenient to operate, but the condensation method requires a high level of cold agent to condense all the methylene chloride, and a deep cooling device at-15 DEG C or even-35 DEG C is needed for freezing treatment to improve the recovery rate of methylene chloride, resulting in high power consumption and increased economic cost.

[0004] The incineration method is a method of decomposing organic pollutants into harmless substances by high temperature, but for the chlorine-containing organic substance methylene chloride, more toxic substances such as dioxin are produced, and it is difficult to stably and accurately control the production of dioxin.

[0005] Therefore, how to provide a methylene chloride recovery system capable of improving the recovery efficiency of methylene chloride and reducing economic cost is an urgent problem to be solved by those skilled in the art. UTILITY MODEL CONTENT

[0006] The utility model aims at overcoming the shortcomings of the prior art, and provides a methylene chloride waste gas recovery system capable of reducing energy consumption and improving the recovery efficiency of methylene chloride.

[0007] The utility model solves the technical problem by adopting the following technical scheme:

[0008] A methylene chloride waste gas recovery system comprises a flame arrester, a filter, a cooling and heating combination device, a first fan, a primary adsorption tank, a secondary adsorption tank, a demister, a desorption tank, a condenser, a gas-liquid separator, a solvent tank and a solvent pump. Methylene chloride tail gas enters the flame arrester, the gas phase outlet end of the flame arrester is connected with the first gas phase inlet end of the filter, the gas phase outlet end of the filter is connected with the gas phase inlet end of the cooling and heating combination device, the gas phase outlet end of the cooling and heating combination device is connected with the inlet end of the first fan, the outlet end of the first fan is connected with the gas phase inlet end of the primary adsorption tank, the gas phase outlet end of the primary adsorption tank is connected with the gas phase inlet end of the secondary adsorption tank, the gas phase outlet end of the secondary adsorption tank is connected with the inlet end of the demister, and the outlet end of the demister is connected with an external connection.

[0009] The high-temperature water vapor enters into a desorption tank, the tank bottom outlet end of the desorption tank is connected with the first inlet end of a condenser, the first outlet end of the condenser is connected with the inlet end of a gas-liquid separator, the gas phase outlet end of the gas-liquid separator is connected with the second gas phase inlet end of a filter, the liquid phase outlet end of the gas-liquid separator is connected with the inlet end of a solvent tank, the outlet end of the solvent tank is connected with the inlet end of a solvent pump, and the outlet end of the solvent pump discharges the dichloromethane solvent.

[0010] Moreover, the high-temperature water vapor also enters into a drying air heater, the gas phase outlet end of the drying air heater is connected with the inlet end of a second air fan, the outlet end of the second air fan is connected with a primary adsorption tank and a secondary adsorption tank respectively, and the liquid phase outlet end of the drying air heater discharges condensate.

[0011] Moreover, the high-temperature water vapor also enters into a cooling and heating combined device, and the second liquid phase outlet end of the cooling and heating combined device discharges condensate.

[0012] Moreover, the cooling and heating combined device comprises a cooler, a tail gas heater and a wire mesh demister, and the wire mesh demister is arranged between the cooler and the tail gas heater.

[0013] Moreover, the first liquid phase inlet end of the cooling and heating combined device is connected with a first water supply pipeline of 7 DEG C water, and the second liquid phase outlet end of the cooling and heating combined device is connected with a first water return pipeline of 7 DEG C water.

[0014] Moreover, the second inlet end of the condenser is connected with a second water supply pipeline of 7 DEG C water, and the second outlet end of the condenser is connected with a second water return pipeline of 7 DEG C water.

[0015] The utility model discloses a cooling and heating combined device, which is used for cooling and heating.

[0016] The utility model discloses a two-stage adsorption technical scheme is recovered to dichloromethane, and is provided with cooling and heating combined device, removes the impurity through cooling and then heats dichloromethane to 30 DEG C, and then enters primary adsorption tank and secondary adsorption tank through first air fan and carries out adsorption, makes the removal rate of dichloromethane reach 99.9% above, thereby realizes the discharge of up to standard.

[0017] The utility model discloses an active carbon material is the air purification carbon that is used for adsorbing dichloromethane, has the characteristics such as high adsorption performance, little desorption residue, low adsorption heat, and the service life is no less than two years, thereby improves the removal rate of dichloromethane, and high-temperature water vapor not only is used for desorption, also is used for heating cooling and heating combined device and second air fan, realizes the purpose of energy saving and consumption reduction. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is the structural schematic diagram of the utility model;

[0019] Reference Signs

[0020] 1-arrester, 2-filter, 3-cooler, 4-wire mesh demister, 5-tail gas heater, 6-first fan, 7-mist eliminator, 8-dry air heater, 9-second fan, 10-second adsorption tank, 11-first adsorption tank, 12-desorption tank, 13-condenser, 14-gas-liquid separator, 15-solvent tank, 16-solvent pump. DETAILED DESCRIPTION

[0021] The utility model will be made further detailed description in combination with the drawings and through specific embodiment, the following embodiment is only descriptive, is not limitative, can not be limited by this the protection scope of the utility model.

[0022] A kind of methylene chloride exhaust gas recovery system, comprising: arrester 1, filter 2, cooling heating combination ware, first fan 6, first adsorption tank 11, second adsorption tank 10, mist eliminator 7, desorption tank 12, condenser 13, gas-liquid separator 14, solvent tank 15 and solvent pump 16, methylene chloride tail gas enters into arrester 1, the gas phase outlet end of arrester 1 is connected with the first gas phase import end of filter 2, the gas phase outlet end of filter 2 is connected with the gas phase import end of cooling heating combination ware, the gas phase outlet end of cooling heating combination ware is connected with the import end of first fan 6, the outlet end of first fan 6 is connected with the gas phase import end of first adsorption tank 11, the gas phase outlet end of first adsorption tank 11 is connected with the gas phase import end of second adsorption tank 10, the gas phase outlet end of second adsorption tank 10 is connected with the import end of mist eliminator 7, the outlet end of mist eliminator 7 is connected with the communication of external connection;

[0023] High-temperature water vapor enters into desorption tank 12, the tank bottom outlet end of desorption tank 12 is connected with the first import end of condenser 13, the first outlet end of condenser 13 is connected with the import end of gas-liquid separator 14, the gas phase outlet end of gas-liquid separator 14 is connected with the second gas phase import end of filter 2, the liquid phase outlet end of gas-liquid separator 14 is connected with the import end of solvent tank 15, the outlet end of solvent tank 15 is connected with the import end of solvent pump 16, the outlet end of solvent pump 16 discharges methylene chloride solvent.

[0024] The adsorption tank used in the embodiment of the utility model is horizontal cylindrical, adopts 316L stainless steel material, the cylinder diameter is Φ2200*12000, mainly consists of tank body, partition and gas distributor.When normal operation, adsorption tank is in normal pressure, slightly positive pressure, slightly negative pressure state, according to GB150 design and manufacture.

[0025] The adsorption material of adsorption tank selects granular activated carbon, and the activated carbon selects air purification carbon specially used for adsorbing methylene chloride, and is specially tested and selected according to the technical requirements and working condition parameters of the project, and the iodine value is greater than or equal to 1050mg / g, the carbon tetrachloride adsorption rate is greater than 80%, and the packing density is about 400kg / m 3The selected activated carbon has the characteristics of high adsorption performance, low desorption residue and low adsorption heat, and the service life of the activated carbon is not less than 2 years under the premise of ensuring standard emission.

[0026] The high-temperature water vapor also enters the drying air heater 8, the gas phase outlet end of the drying air heater 8 is connected with the inlet end of the second air fan 9, the outlet end of the second air fan 9 is connected with the first adsorption tank 11 and the second adsorption tank 10 respectively, so that the drying air can blow the activated carbon bed when the desorption is completed; the liquid phase outlet end of the drying air heater 8 discharges the condensate.

[0027] The high-temperature water vapor also enters the cooling and heating combined device, and the second liquid phase outlet end of the cooling and heating combined device discharges the condensate.

[0028] The cooling and heating combined device comprises the cooler 3, the tail gas heater 5 and the wire mesh demister 4, and the wire mesh demister 4 is arranged between the cooler 3 and the tail gas heater 5.

[0029] The first liquid phase inlet end of the cooling and heating combined device is connected with the first water supply pipeline of 7 DEG C water, and the second liquid phase outlet end of the cooling and heating combined device is connected with the first water return pipeline of 7 DEG C water, so that the tail gas in the cooling and heating combined device can be cooled.

[0030] The second inlet end of the condenser 13 is connected with the second water supply pipeline of 7 DEG C water, and the second outlet end of the condenser 13 is connected with the second water return pipeline of 7 DEG C water, so that the tail gas in the cooling and heating combined device can be cooled.

[0031] Although the embodiments and drawings of the utility model are disclosed for the purpose of illustration, those skilled in the art can understand that various substitutions, changes and modifications are possible without departing from the spirit and scope of the utility model and the appended claims, therefore, the scope of the utility model is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A system for recovering dichloromethane off-gas, characterized by: The device comprises a flame arrester, a filter, a cooling and heating combined device, a first fan, a first-stage adsorption tank, a second-stage adsorption tank, a demister, a desorption tank, a condenser, a gas-liquid separator, a solvent tank and a solvent pump. Dichloromethane tail gas enters the flame arrester, the gas phase outlet end of the flame arrester is connected with the first gas phase inlet end of the filter, the gas phase outlet end of the filter is connected with the gas phase inlet end of the cooling and heating combined device, the gas phase outlet end of the cooling and heating combined device is connected with the inlet end of the first fan, the outlet end of the first fan is connected with the gas phase inlet end of the first-stage adsorption tank, the gas phase outlet end of the first-stage adsorption tank is connected with the gas phase inlet end of the second-stage adsorption tank, the gas phase outlet end of the second-stage adsorption tank is connected with the inlet end of the demister, and the outlet end of the demister is connected with an external connection. High-temperature water vapor enters the desorption tank, the tank bottom outlet end of the desorption tank is connected with the first inlet end of the condenser, the first outlet end of the condenser is connected with the inlet end of the gas-liquid separator, the gas phase outlet end of the gas-liquid separator is connected with the second gas phase inlet end of the filter, the liquid phase outlet end of the gas-liquid separator is connected with the inlet end of the solvent tank, the outlet end of the solvent tank is connected with the inlet end of the solvent pump, and the outlet end of the solvent pump discharges dichloromethane solvent. The high-temperature water vapor also enters the drying air heater, the gas phase outlet end of the drying air heater is connected with the inlet end of the second fan, the outlet end of the second fan is connected with the first-stage adsorption tank and the second-stage adsorption tank respectively, and the liquid phase outlet end of the drying air heater discharges condensate.

2. The system for recovering dichloromethane exhaust gas according to claim 1, wherein: The high-temperature water vapor also enters the cooling and heating combined device, and the second liquid phase outlet end of the cooling and heating combined device discharges condensate.

3. The system for recovering dichloromethane exhaust gas according to claim 2, characterized by: The cooling and heating combined device comprises a cooler, a tail gas heater and a wire mesh demister, and the wire mesh demister is arranged between the cooler and the tail gas heater.

4. The system for recovering dichloromethane exhaust gas according to claim 1, wherein: The first liquid phase inlet end of the cooling and heating combined device is connected with a first water supply pipeline of 7 ℃ water, and the second liquid phase outlet end of the cooling and heating combined device is connected with a first water return pipeline of 7 ℃ water.

5. The system for recovering dichloromethane exhaust gas according to claim 1, wherein: The second inlet end of the condenser is connected with a second water supply pipeline of 7 ℃ water, and the second outlet end of the condenser is connected with a second water return pipeline of 7 ℃ water.

6. The system for recovering dichloromethane exhaust gas according to claim 1, wherein: ​

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