Vacuum tail gas efficient purification and recovery device

Abstract

The utility model discloses a vacuum tail gas efficient purification and recovery device which comprises a pre-pumping buffer tank, a vacuum pump is arranged at the gas output end of the pre-pumping buffer tank, a primary condenser is arranged at the gas output end of the vacuum pump, and a small gas-liquid separator is arranged between the vacuum pump and the primary condenser. The gas output end of the first-stage condenser is provided with a combined tube nest condensation catcher, the combined tube nest condensation catcher comprises a second-stage condenser, a third-stage condenser and a liquid collecting tank, the tail end of the combined tube nest condensation catcher is provided with a fourth-stage condenser, and the liquid output end of the fourth-stage condenser is provided with a solvent receiving tank; a positive and negative pressure water-sealed tank is arranged at the gas output end of the fourth-stage condenser; a resin adsorption and desorption device is arranged at the gas output end of the positive and negative pressure water-sealed tank; the device disclosed by the utility model has the advantages of low equipment damage rate, good condensation effect, high solvent recovery efficiency, better VOC (Volatile Organic Compounds) removal effect and the like.

Description

TECHNICAL FIELD

[0001] The utility model belongs to tail gas desorption equipment technical field especially relates to a vacuum tail gas efficient purification and recovery device. BACKGROUND

[0002] Various waste gas including volatile organic compounds (VOCs), acid gas, malodorous gas and the like will be produced in the production process, which will not only pollute the surrounding environment but also affect human life safety and health if discharged into the atmosphere. With the continuous improvement of environmental protection requirements, the research and application of new technology, new material, new equipment and new technology are promoted, and the efficiency and effect of waste gas treatment are improved.

[0003] In the process of pharmaceutical intermediates production, a large amount of gasified organic solvent will be extracted into the tail gas system by using negative pressure vacuum system. If the tail gas treatment system is not reasonably designed, it will cause low solvent condensation and recovery efficiency, concentration exceeding standard and substandard phenomenon, thereby causing surrounding environmental pollution. The conventional tail gas pretreatment system is composed of vacuum pump + cold trap (circulating water) + first-stage condenser (-15 DEG C), and the following disadvantages exist during operation: condensed solvent flows back into the vacuum pump, causing vacuum pump failure or damage; poor condensation effect, about 10-20L / day of solvent such as dimethyl ether is condensed and recovered, and most of the solvent gas is directly introduced into the tail gas end treatment unit RTO, causing the concentration of inlet gas VOC to exceed the standard, and when the accumulation reaches the explosion limit, there is a risk of explosion and emergency shutdown.

[0004] At present, with the increasingly severe environmental protection situation, the requirements for solvent condensation and recovery efficiency and VOC removal effect of tail gas pretreatment in the vacuum pump area are higher and higher, and environmental protection reconstruction is imperative. INVENTION CONTENTS

[0005] The utility model discloses a vacuum tail gas efficient purification and recovery device which can solve the problems of easy equipment damage, poor condensation effect, low solvent condensation and recovery efficiency and poor VOC removal effect of the conventional tail gas treatment system.

[0006] The utility model discloses a vacuum tail gas efficient purification and recovery device which can solve the problems of easy equipment damage, poor condensation effect, low solvent condensation and recovery efficiency and poor VOC removal effect of the conventional tail gas treatment system. The utility model discloses a vacuum tail gas efficient purification and recovery device which can solve the problems of easy equipment damage, poor condensation effect, low solvent condensation and recovery efficiency and poor VOC removal effect of the conventional tail gas treatment system.

[0007] Further, the liquid output end of the small gas-liquid separator is connected with the liquid collecting tank, the input end of the secondary condenser is connected with the gas output end of the primary condenser, and the input end of the tertiary condenser is connected with the gas output end of the secondary condenser.

[0008] Further, a liquid seal pipeline is arranged between the small gas-liquid separator and the liquid collecting tank, the liquid seal pipeline is a concave U-shaped pipe, and a discharge valve is arranged at the bottom of the liquid seal pipeline.

[0009] Further, the small gas-liquid separator comprises a tank body, an input port is arranged through the tank body laterally, a liquid output port is arranged through the bottom of the tank body, a circular pipe is arranged through the top wall of the tank body, the bottom of the circular pipe is located in the tank body, and a gas output port is arranged at the top of the circular pipe.

[0010] Further, the bottom of the circular pipe is designed as a bevel cut opening, and the bevel of the bevel cut opening faces away from the input port.

[0011] Beneficial effects: the utility model discloses the following beneficial effects:

[0012] 1. In the utility model scheme, through system route, chemical substance analysis, workshop research and theoretical innovation research design, the vacuum tail gas efficient purification and recovery device adopts vacuum pump + small gas-liquid separator + primary condensation (circulating water) + secondary condensation (7 DEG C) + tertiary condensation (-15 DEG C) + four-stage condensation (-15 DEG C) + resin adsorption / desorption device, effectively solve the VOC concentration overproof and the frequency of vacuum pump damage, the innovation design and application of the novel system of vacuum pump tail gas pretreatment effectively improve the organic solvent recovery rate, so that it can be recycled, which reduces the procurement cost of organic solvents and reduces the environmental risk caused by emission, ensures that the tail gas treatment device operates stably and meets the emission standard.

[0013] 2. In the utility model scheme, the "liquid seal pipeline" is designed to ensure that the condensate flows into the liquid collecting tank by gravity flow principle, prevent being taken away by tail gas negative pressure gas flow or directly entering the liquid collecting tank by vacuum exhaust gas, and avoid the adverse phenomenon that the tail gas is not condensed and is directly extracted.

[0014] 3. In the utility model scheme, the "small gas-liquid separator" is designed, which is non-standard customized design, effectively separates gas-liquid two-phase, prevents liquid phase from pouring into the vacuum pump cavity, and greatly reduces the damage frequency of the vacuum pump. BRIEF DESCRIPTION OF DRAWINGS

[0015] Fig. 1 It is a schematic view of the vacuum tail gas efficient purification and recovery device.

[0016] Fig. 2A partial structure schematic view of the vacuum tail gas efficient purification and recovery device of the utility model is shown in the figure.

[0017] Fig. 3 A structure schematic view of the small gas-liquid separator of the utility model is shown in the figure.

[0018] Fig. 4 A sampling and detection result table of the utility model is shown in the figure.

[0019] In the figure, 1 is a pre-pump buffer tank, 2 is a vacuum pump, 3 is a primary condenser, 4 is a small gas-liquid separator, 5 is a combined tube condensing trap, 6 is a four-stage condenser, 7 is a solvent receiving tank, 8 is a positive and negative pressure water seal tank, 9 is a resin adsorption and desorption device, and 10 is a liquid seal pipeline.

[0020] 401 is a tank body, 402 is an input port, 403 is a liquid output port, 404 is a circular pipe, 405 is a gas output port, 501 is a secondary condenser, 502 is a tertiary condenser, and 503 is a liquid collecting tank. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments.

[0022] In combination Figs. 1 to 4 A vacuum tail gas efficient purification and recovery device is shown in the figure, which comprises a pre-pump buffer tank 1, a gas output end of the pre-pump buffer tank 1 is provided with a vacuum pump 2, a gas output end of the vacuum pump 2 is provided with a primary condenser 3, a small gas-liquid separator 4 is arranged between the vacuum pump 2 and the primary condenser 3, a gas output end of the primary condenser 3 is provided with a combined tube condensing trap 5, the combined tube condensing trap 5 comprises a secondary condenser 501, a tertiary condenser 502 and a liquid collecting tank 503, a fourth condenser 6 is arranged at the end of the combined tube condensing trap 5, a liquid output end of the fourth condenser 6 is provided with a solvent receiving tank 7, a gas output end of the fourth condenser 6 is provided with a positive and negative pressure water seal tank 8, and a gas output end of the positive and negative pressure water seal tank 8 is provided with a resin adsorption and desorption device 9.

[0023] The liquid output end of the small gas-liquid separator 4 is connected with the liquid collecting tank 503, the input end of the secondary condenser 501 is connected with the gas output end of the primary condenser 3, and the input end of the tertiary condenser 502 is connected with the gas output end of the secondary condenser 501.

[0024] The liquid seal pipeline 10 is a concave U-shaped pipe, and the bottom of the liquid seal pipeline 10 is provided with a discharge valve. The liquid seal pipeline 10 ensures that the condensed liquid in the small gas-liquid separator 4 flows into the liquid collecting tank 503 by gravity flow principle, prevents being brought into the primary condenser 3 by the tail gas negative pressure gas flow or being directly into the liquid collecting tank 503 by the vacuum exhaust gas.

[0025] The small gas-liquid separator 4 comprises a tank body 401, the outer side of the tank body 401 is provided with an input port 402 in a transverse through manner, the bottom of the tank body 401 is provided with a liquid output port 403 in a through manner, and a circular pipe 404 is provided on the top wall of the tank body 401 in a penetrating manner. The bottom of the circular pipe 404 is located in the interior of the tank body 401, and the top of the circular pipe 404 is provided with a gas output port 405.

[0026] The bottom of the circular pipe 404 is designed as a bevel cut opening, and the bevel of the bevel cut opening faces away from the input port 402. The small gas-liquid separator 4 can effectively separate the gas-liquid two-phase and prevent the liquid phase from flowing back into the cavity of the vacuum pump 2.

[0027] The primary condenser 3 adopts circulating water for condensation, and the condensation temperature of the secondary condenser 501, the tertiary condenser 502 and the quaternary condenser 6 is in the range of 7℃ to -15℃.

[0028] The new high-efficiency purification and recovery device is installed and has been put into operation. The examples are shown below:

[0029] The average condensation and recovery amount of organic solvents such as dimethyl ether in the tail gas quaternary condensation in the vacuum pump area of the A6 / A7 process in the workshop is 400-600L / day, the solvent reuse rate is increased by more than 98%, and the solvent loss is reduced.

[0030] The average removal efficiency of VOC (non-methane total hydrocarbon) of the resin adsorption / desorption device is 98.39%, the average concentration of the outlet exhaust gas is 750mg / m3, which meets the inlet concentration of the end treatment device RTO and meets the standard treatment and emission. The treatment effect of the resin adsorption / desorption device is shown in the sampling detection results as shown in Table (I):

[0031]

[0032] Table (I)

[0033] It is apparent for a person skilled in the art that the present application is not limited to the details of the above-described exemplary embodiments, but that it can be implemented in other concrete forms without departing from the spirit or the essential characteristics of the present application. Therefore, the embodiments should be considered as exemplary and non-limiting, the scope of the present application being defined by the claims appended hereto rather than by the above description, and all the changes which fall within the meaning and the scope of the equivalent elements of the claims are intended to be embraced therein. Any reference signs in the claims should not be construed as limiting the claims to the figures in which the reference signs are used.

[0034] Furthermore, it should be understood that although the present specification describes exemplary embodiments, not every embodiment contains only one independent technical solution, and the present specification is described in this way only for the sake of clarity, and a person skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that a person skilled in the art can understand.

Claims

1. A vacuum tail gas high-efficiency purification and recovery device, comprising a pre-pump buffer tank (1), a gas output end of the pre-pump buffer tank (1) is provided with a vacuum pump (2), a gas output end of the vacuum pump (2) is provided with a first condenser (3), characterized in that: The vacuum pump (2) is provided with a small gas-liquid separator (4) between the primary condenser (3), the gas output end of the primary condenser (3) is provided with a combined tube condensing trap (5), the combined tube condensing trap (5) comprises a secondary condenser (501), a tertiary condenser (502) and a liquid collecting tank (503), the combined tube condensing trap (5) is provided with a quaternary condenser (6) at the end, the liquid output end of the quaternary condenser (6) is provided with a solvent receiving tank (7), the gas output end of the quaternary condenser (6) is provided with a positive and negative pressure water seal tank (8), the gas output end of the positive and negative pressure water seal tank (8) is provided with a resin adsorption and desorption device (9).

2. The vacuum tail gas high-efficiency purification and recovery device according to claim 1, characterized in that: The liquid output end of the small gas-liquid separator (4) is connected with the liquid collecting tank (503), the input end of the secondary condenser (501) is connected with the gas output end of the primary condenser (3), and the input end of the tertiary condenser (502) is connected with the gas output end of the secondary condenser (501).

3. The vacuum tail gas high-efficiency purification and recovery device according to claim 2, characterized in that: The small gas-liquid separator (4) and the liquid collecting tank (503) are provided with a liquid seal pipeline (10), the liquid seal pipeline (10) is a concave U-shaped tube, and the bottom of the liquid seal pipeline (10) is provided with a discharge valve.

4. The vacuum tail gas high-efficiency purification and recovery device according to claim 3, characterized in that: The small gas-liquid separator (4) comprises a tank body (401), the outer side of the tank body (401) is provided with an input port (402) transversely penetrating, the bottom of the tank body (401) is provided with a liquid output port (403) penetrating, a circular pipe (404) is provided on the top wall of the tank body (401) penetrating, the bottom of the circular pipe (404) is located in the tank body (401), and the top of the circular pipe (404) is provided with a gas output port (405).

5. The vacuum tail gas high-efficiency purification and recovery device according to claim 4, characterized in that: The bottom of the circular pipe (404) is designed as a bevel cut opening, and the slope of the bevel cut opening faces away from the input port (402).

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