Volatile organic compound absorption tower and volatile organic compound absorption system

Abstract

The utility model relates to the field of volatile organic compound absorption equipment, and discloses a volatile organic compound absorption tower which comprises a tower body, and a poor organic absorbent distributor, a packing layer and a plug-in heat exchanger are sequentially arranged in the tower body from top to bottom; the filler layer is arranged below the poor organic absorbent distributor, and the plug-in heat exchanger is arranged below the filler layer; a riser and a downcomer are arranged on the plug-in heat exchanger, one end of the riser is arranged on the plug-in heat exchanger, the other end of the riser extends towards the filler layer, one end of the downcomer is arranged on the plug-in heat exchanger, and the other end of the downcomer extends towards the bottom of the tower body. The volatile organic compound absorption tower can maintain the temperature of the filler layer, avoid reduction of the absorption efficiency, reduce the treatment load of the absorption tower, save the use amount of the organic absorbent, reduce the influence of liquid carried by tail gas on the absorption effect of the filler layer, and ensure a better gas-liquid ratio by controlling the flow proportion of the tail gas and the organic absorbent.

Description

Technical Field

[0001] The utility model relates to the field of volatile organic matter absorption equipment, in particular to a volatile organic matter absorption tower and a volatile organic matter absorption system. Background Art

[0002] Volatile organic compounds, commonly referred to as VOCs, are defined by the World Health Organization (WHO) as various organic compounds with a boiling point of 50°C to 260°C at room temperature. In my country, VOCs refer to organic compounds with a saturated vapor pressure greater than 70Pa at room temperature and a boiling point below 260°C at normal pressure, or all organic compounds with a vapor pressure greater than or equal to 10Pa at 20°C and volatility.

[0003] VOCs are usually divided into several categories, including non-methane hydrocarbons (NMHCs), oxygen-containing organic compounds, halogenated hydrocarbons, nitrogen-containing organic compounds, and sulfur-containing organic compounds. VOCs participate in the formation of ozone and secondary aerosols in the atmospheric environment, and have an important impact on regional atmospheric ozone pollution and PM2.5 pollution. Most VOCs have a special unpleasant odor and are toxic, irritating, teratogenic, and carcinogenic. In particular, benzene, toluene, and formaldehyde can cause great harm to human health.

[0004] VOCs are important precursors to urban haze and photochemical smog, and are mainly derived from coal chemical industry, petrochemical industry, fuel coating manufacturing, solvent manufacturing and use, and other processes. Among these industries, the petrochemical industry has the widest impact and the most serious pollution. According to statistics, the total amount of VOCs emissions related to my country's industry in 2010 was 13 million tons, of which the petrochemical industry accounted for 2.1 million tons. In 2011, the petrochemical industry still ranked first in my country's industrial VOCs emissions. Therefore, to thoroughly control my country's VOCs, the petrochemical industry cannot be avoided. However, petrochemical enterprises have complex production, a wide variety of types, and many emission sources, making detection and control difficult. According to the simple classification of the "Guidelines for the Investigation of VOCs Pollution Sources in Petrochemical Enterprises", the VOCs emission sources of petrochemical enterprises can be roughly divided into 12 major items, including leakage at equipment sealing points, organic liquid storage loss, and organic liquid loading and unloading loss. Most of them are in storage tank areas or loading areas. Therefore, the treatment of exhaust gas generated by oil tankers is an important part of the treatment of VOCs in petrochemical enterprises.

[0005] The existing conventional treatment process mainly involves sending the tail gas (including volatile organic compounds) generated by the tank area and loading to the entrance of the volatile organic compound absorption tower after being pressurized by the liquid ring compressor, and then contacting the organic absorbent from the top from bottom to top in the packing layer in countercurrent to remove the volatile organic compounds in the tail gas. After the organic absorbent is cooled to a suitable low temperature by the refrigeration facility, it enters the volatile organic compound absorption tower, and contacts the tail gas (including volatile organic compounds) from top to bottom in the packing layer in countercurrent to absorb the volatile organic compounds in the tail gas. However, the tail gas in the tank area is affected by the air temperature and operating conditions (such as changes in feed volume and tank inversion), and the amount of tail gas and the temperature of the tail gas generated vary greatly; the tail gas from loading is affected by the air temperature and the number of loading vehicles, and the amount of tail gas and the temperature of the tail gas generated also vary greatly; which leads to the low efficiency of this treatment method, and the organic absorbent flow cannot be adjusted in real time according to the tail gas volume, and the absorption tower cannot be guaranteed to operate within the optimal gas-liquid ratio range, which is not conducive to energy saving for enterprises.

[0006] In view of this, it is necessary to design a new volatile organic compound absorption device to overcome or alleviate the above technical problems. Utility Model Content

[0007] The first technical problem to be solved by the utility model is to provide a volatile organic compound absorption tower, which can maintain the temperature of the packing layer, avoid the reduction of absorption efficiency, reduce the processing load of the absorption tower, save the amount of organic absorbent, and reduce the influence of tail gas liquid on the absorption effect of the packing layer.

[0008] The second technical problem to be solved by the utility model is to provide a volatile organic matter absorption system, which ensures a better gas-liquid ratio and saves the amount of organic absorbent by controlling the flow ratio of tail gas and organic absorbent.

[0009] In order to solve the above technical problems, the first aspect of the utility model provides a volatile organic compound absorption tower, including a tower body, in which an absorbent distributor, a packing layer and an inserted heat exchanger are arranged in sequence from top to bottom; the inserted heat exchanger includes a hollow shell side portion and a hollow tube side portion in contact with the shell side portion, the side wall of the shell side portion is provided with a shell side inlet, a gas phase outlet toward the packing layer and a liquid phase outlet toward the bottom of the tower body, the side wall of the tube side portion is provided with a tube side inlet and a tube side outlet, and the tube side inlet is connected to the liquid outlet at the bottom of the tower body.

[0010] Furthermore, the tower bottom liquid outlet is connected to the tube side inlet through a reflux pipe, a bypass pipe is provided on the side wall of the reflux pipe, and a second regulating valve is provided on the bypass pipe.

[0011] Furthermore, a thermometer for monitoring the temperature inside the tower body is provided on the tower body, and the thermometer is electrically connected to the second regulating valve.

[0012] Furthermore, a riser is provided on the gas phase outlet, and the riser extends toward the packing layer; a coalescing and deliquoring filter is provided in the riser.

[0013] Furthermore, a baffle is provided on the inner wall of the tower body, the baffle is placed above the riser, and the baffle extends obliquely downward from the side wall of the tower body.

[0014] Furthermore, a downcomer is provided on the liquid phase outlet, and the downcomer extends toward the bottom of the tower body.

[0015] Furthermore, a liquid sealing pipe is provided below the downcomer, the liquid sealing pipe is fixed on the inner wall of the tower body, and the end of the downcomer extends into the liquid sealing pipe to form an overflow structure.

[0016] Furthermore, the absorbent distributor includes a liquid separatory tube, one end of which is located outside the tower body and the other end is inserted into the tower body. The portion of the liquid separatory tube inserted into the tower body is provided with a nozzle facing the packing layer. The end of the liquid separatory tube placed outside the tower body is connected to an absorbent feed pipe, and a first regulating valve is provided on the absorbent feed pipe.

[0017] Furthermore, a tail gas flow meter for detecting the gas flow at the gas phase outlet is provided on the tower body, and the tail gas flow meter is electrically connected to the first regulating valve.

[0018] A second aspect of the utility model provides a volatile organic matter absorption system, comprising a volatile organic matter absorption tower.

[0019] Furthermore, the tower bottom liquid outlet is connected to the tube side inlet through a reflux pipe, and the tube side outlet and the side wall of the reflux pipe are both connected to the tower bottom liquid storage tank; the feed end of the absorbent distributor is connected to a refrigeration device.

[0020] Through the above technical scheme, the volatile organic compound absorption tower provided by the utility model is provided with an absorbent distributor, a packing layer and an inserted heat exchanger for spraying a lean organic absorbent in the tower body in sequence from top to bottom; the inserted heat exchanger is used to exchange heat between the original tail gas and the bottom liquid of the tower, so as to realize cooling of the original tail gas, so as to condense a part of the volatile organic compounds in the original tail gas in advance; the cooled tail gas (including the volatile organic compounds) is transported from the gas phase outlet to the packing layer to contact with the absorbent, effectively reducing the processing load of the absorption tower and saving the amount of organic absorbent; the liquid obtained by condensing the tail gas is transported to the bottom of the tower body through the liquid phase outlet to be mixed with the rich organic absorbent and discharged; the temperature in the absorption tower can be effectively adjusted by the heat exchange cooling of the original tail gas by the bottom liquid of the tower, and the stability of the temperature of the packing layer of the absorption tower can be improved, thereby maintaining the absorption efficiency.

[0021] Other features and advantages of the present invention will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but do not constitute a limitation to the present invention. In the accompanying drawings:

[0023] Figure 1 It is a structural schematic diagram of a volatile organic compound absorption tower in a specific embodiment of the utility model;

[0024] Figure 2 It is a structural schematic diagram of an insertable heat exchanger in a specific embodiment of the utility model;

[0025] Figure 3 It is a schematic diagram of the process of the volatile organic compound absorption tower in a specific embodiment of the utility model.

[0026] Description of Reference Numerals

[0027] DETAILED DESCRIPTION

[0028] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation modes described herein are only used to illustrate and explain the present invention, and the protection scope of the present invention is not limited to the specific implementation modes described below.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "disposed", "provided with", "installed", and "connected" should be understood in a broad sense. For example, the connection can be a direct connection or an indirect connection through an intermediate medium, a fixed connection, a detachable connection, an integral connection, or a connection between two elements or an interaction between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] In addition, the terms "first", "second", "third", "fourth" and "fifth" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", "third", "fourth" and "fifth" may explicitly or implicitly include one or more of the said features.

[0031] In the present invention, unless otherwise specified, the directional words used, such as "inside" and "outside", are defined as the inside and outside of the corresponding parts. In addition, in the drawings provided in the present invention, the orientation or position relationship used is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention. The orientation terms of the present invention should be understood in conjunction with the actual installation status.

[0032] See also Figures 1 to 3 The utility model provides a volatile organic compound absorption tower, comprising a tower body 1, in which an absorbent distributor 2, a packing layer 3 and an inserted heat exchanger 4 are arranged in sequence from top to bottom; the inserted heat exchanger 4 comprises a hollow shell-side portion and a hollow tube-side portion in contact with the shell-side portion, a shell-side inlet 43, a gas phase outlet toward the packing layer 3 and a liquid phase outlet toward the bottom of the tower body 1 are arranged on the side wall of the shell-side portion, a tube-side inlet 42 and a tube-side outlet 41 are arranged on the side wall of the tube-side portion, and the tube-side inlet 42 is connected to the liquid outlet at the bottom of the tower body 1.

[0033] After the tail gas containing volatile organic compounds to be treated (hereinafter referred to as "original tail gas" for ease of description) passes through the plug-in heat exchanger 4, the temperature of the original tail gas is reduced, and the part of volatile organic compounds rich therein is liquefied, flowing out of the plug-in heat exchanger 4 to the bottom of the tower body 1 and gathering at the bottom of the tower body 1. At this time, the original tail gas separates part of the volatile organic compounds in the original tail gas through heat exchange, which is called the primary purification of the original tail gas. For the convenience of subsequent description, the original tail gas after the primary purification is called the intermediate tail gas. After the intermediate tail gas is discharged from the plug-in heat exchanger 4, it enters the tower body 1 and contacts with the packing layer 3 in the tower body 1. The packing layer 3 can be a ball ring or a Raschig ring. The intermediate tail gas is more evenly distributed after passing through the ball ring or the Raschig ring.

[0034] The plug-in heat exchanger 4 includes a hollow shell-side portion and a hollow tube-side portion, and the shell-side portion and the tube-side portion are in contact with each other to achieve heat exchange; a shell-side inlet 43, a gas phase outlet and a liquid phase outlet are provided on the side wall of the shell-side portion, and a tube-side outlet 41 and a tube-side inlet 42 are provided on the side wall of the tube-side portion; the gas phase outlet faces the packing layer 3, and the intermediate tail gas is discharged from the gas phase outlet at the packing layer 3 to meet the absorbent sprayed from the absorbent distributor 2 sprayed with the lean organic absorbent distributor, and then secondary purification is performed. For ease of description, the intermediate tail gas after secondary purification is called purified tail gas, and the absorbent absorbs the volatile organic matter in the intermediate tail gas to form a rich organic absorbent cold liquid. The liquid phase outlet faces the bottom of the tower body 1, and part of the volatile organic matter liquid formed by heat exchange cooling accumulates from the liquid phase outlet to the bottom of the tower body 1. The tube-side inlet 42 is connected to the bottom liquid outlet at the bottom of the tower body 1, so that the liquid accumulated at the bottom of the tower body 1 can flow back to the plug-in heat exchanger 4 to participate in heat exchange.

[0035] The organic absorbent-rich cold liquid and the liquid containing some volatile organic matter are mixed at the bottom of the tower body 1 to form a tower bottom liquid, and a tower bottom liquid outlet is provided at the bottom of the tower body 1. The tower bottom liquid outlet at the bottom of the tower body 1 can be connected to the pipe side inlet 42 through the reflux pipe 7 so that the organic absorbent-rich cold liquid can return to the inside of the plug-in heat exchanger 4 to exchange heat with the original tail gas, thereby reducing the amount of refrigerant and being more environmentally friendly. A second regulating valve 72 is provided on the bypass pipe 71, so that the flow rate of the tower bottom liquid refluxed to the plug-in heat exchanger 4 is adjusted by the second regulating valve 72, and the flow rate entering the pipe side of the plug-in heat exchanger 4 is indirectly controlled to adjust the temperature of the absorption tower, so as to ensure that the temperature of the absorption tower packing layer 3 remains unchanged. If the temperature of the absorption tower packing layer is stable, the absorption efficiency remains unchanged.

[0036] In some embodiments, a thermometer 11 may be provided on the tower body 1, and the thermometer 11 is electrically connected to the second regulating valve 72. The thermometer 11 is fixed on the outer wall of the tower body 1, and a probe of the thermometer 11 is inserted into the tower body 1. The temperature inside the tower body 1 is detected by the thermometer 11, and the temperature detected by the thermometer 11 can be used as a signal to control the opening of the second regulating valve 72, thereby realizing the linkage between the temperature inside the tower body 1 and the second regulating valve 72.

[0037] In some embodiments, a riser 5 is fixed on the gas phase outlet, and the riser 5 faces the packing layer 3. The shell side inlet 43 is used for the original tail gas to enter the tower body 1. After heat exchange in the tower body 1, the temperature drops and some volatile organic matter is removed to form an intermediate tail gas, and the intermediate tail gas is discharged to the packing layer 3 through the riser 5. A coalescing and deliquescence filter 52 is provided in the riser 5. The coalescing and deliquescence filter 52 can remove the droplets entrained in the intermediate tail gas and reduce the influence of the tail gas carrying liquid on the absorption effect of the packing layer 3. A baffle 51 can be provided between the riser 5 and the packing layer 3. The baffle 51 is fixed on the inner wall of the tower body 1 and placed above the riser 5. The baffle 51 is arranged obliquely and the end of the baffle 51 away from the tower body 1 extends to the bottom of the tower body 1 to prevent the cold liquid rich in organic absorbent from entering the plug-in heat exchanger 4.

[0038] In some embodiments, a downcomer 6 may be fixed on the liquid phase outlet, and part of the volatile organic matter liquefied by heat exchange is discharged through the downcomer 6. The downcomer 6 extends toward the bottom of the tower body 1, and then accumulates at the bottom of the tower body 1. A liquid seal pipe 61 is provided below the downcomer 6 to form an overflow structure. Part of the volatile organic matter liquefied by heat exchange first enters the liquid seal pipe 61, eventually fills the liquid seal pipe 61, overflows from the liquid seal pipe 61, and finally falls to the bottom of the tower body 1, reducing the possibility of gas that has not been deliquated entering the absorption tower through the downcomer 6.

[0039] In some embodiments, the absorbent distributor 2 includes a liquid distributor 21, which is inserted into the tower body 1. The portion of the liquid distributor 21 inserted into the tower body 1 is provided with a nozzle 22, which faces the packing layer 3. One end of the liquid distributor 21 placed outside the tower body 1 is connected to a refrigeration device 23, which is used to cool the lean organic absorbent flowing through the liquid distributor 21 to form lean organic absorbent cold liquid, which is sprayed out by the nozzle 22. A first regulating valve 24 for regulating the flow rate of the liquid distributor 21 is provided between the refrigeration device 23 and the liquid distributor 21. The lean organic absorbent cold liquid is pumped into the liquid distributor 21 and sprayed out by the nozzle 22, so that the lean organic absorbent is evenly sprayed on the packing layer 3. The intermediate tail gas flowing from bottom to top is fully contacted with the lean organic absorbent cold liquid flowing from top to bottom at the packing layer 3, thereby realizing the secondary purification of the intermediate tail gas. After the primary purification and the secondary purification, the volatile organic matter content of the original tail gas is further reduced, and the original tail gas is purified more thoroughly.

[0040] After the lean organic absorbent cold liquid fully contacts the intermediate tail gas, it absorbs the volatile organic matter in the intermediate tail gas to form a rich organic absorbent cold liquid. Since the tail gas has been purified once, the temperature of the tail gas is reduced. Therefore, the lean organic absorbent cold liquid fully contacts the cooled intermediate tail gas to form a rich organic absorbent cold liquid. The rich organic absorbent cold liquid can flow back to the plug-in heat exchanger 4 as a refrigerant to exchange heat with the original tail gas entering the plug-in heat exchanger 4.

[0041] In some embodiments, a tail gas flowmeter 12 is also fixed on the tower body 1. The probe of the tail gas flowmeter 12 is inserted into the tower body 1 and placed at one end of the riser 5 facing the packing layer 3. An organic absorbent flowmeter can be provided on the liquid separation pipe 21 to detect the flow rate of the lean organic absorbent cold liquid sent into the tower body 1. The organic absorbent flowmeter and the tail gas flowmeter 12 can be linked with the first regulating valve 24, and the opening of the first regulating valve 24 can be controlled by the flow signal, so as to control the gas-liquid ratio in real time within the optimal range, ensure a better gas-liquid ratio, and reduce the amount of organic absorbent cold liquid.

[0042] Based on the above-mentioned volatile organic compound absorption tower, the utility model also provides a volatile organic compound absorption system, in which the bottom liquid outlet of the tower is connected to the tube side inlet 42 through a reflux pipe 7, and the side walls of the tube side outlet 41 and the reflux pipe 7 are both connected to the bottom liquid storage tank 10; the feed end of the absorbent distributor 2 is connected to the refrigeration equipment.

[0043] A liquid ring compressor 8 may be provided at the shell side inlet 43, and the liquid ring compressor 8 compresses the shell side inlet 43 and compresses and pumps the original tail gas into the shell side inlet 43. The rich organic absorbent after heat exchange is transported from the tube side outlet 41 to the storage tank 10 for temporary storage. The storage tank 10 is provided with an external delivery pump 9 so that when the rich organic absorbent fills the storage tank 10, the rich organic absorbent in the storage tank 10 can be extracted, which is convenient for recycling the rich organic absorbent in the storage tank 10, and is more environmentally friendly.

[0044] In the best embodiment, the plug-in heat exchanger 4 is fixed at the lower part of the tower body 1. A liquid ring compressor 8 can be set at the shell side inlet 43 of the plug-in heat exchanger 4, and the liquid ring compressor 8 compresses the shell side inlet 43 and compresses and pumps the original tail gas into the shell side inlet 43. The tower bottom liquid outlet is connected to the tube side inlet 42 through the reflux pipe 7, and the tube side outlet 41 and the side wall of the reflux pipe 7 are connected to the tower bottom liquid storage tank 10; the feed end of the absorbent distributor 2 is connected to the refrigeration equipment. The gas phase outlet of the plug-in heat exchanger 4 is fixed with a riser pipe 5, and the riser pipe 5 faces the packing layer 3. A coalescing and deliquidation filter element 52 is provided in the riser pipe 5. A baffle 51 is arranged between the riser pipe 5 and the packing layer 3, and the baffle 51 is fixed on the inner wall of the tower body 1 and placed above the riser pipe 5. The baffle 51 is arranged obliquely and the end of the baffle 51 away from the tower body 1 extends to the bottom of the tower body 1. An absorbent distributor 2 is fixed on the top of the tower body 1, and the absorbent distributor 2 sprays liquid to the packing layer 3. A thermometer 11 can be arranged on the tower body 1, and the thermometer 11 is electrically connected to the second regulating valve 72. The thermometer 11 is fixed on the outer wall of the tower body 1, and the probe of the thermometer 11 is inserted into the tower body 1. The temperature detected by the thermometer 11 can be used as a signal to control the opening of the second regulating valve 72. A tail gas flowmeter 12 is also fixed on the tower body 1. The probe of the tail gas flowmeter 12 is inserted into the tower body 1 and is placed at one end of the riser 5 facing the packing layer 3. An organic absorbent flowmeter can be arranged on the liquid distribution pipe 21 to detect the flow rate of the lean organic absorbent cold liquid sent into the tower body 1. The organic absorbent flowmeter and the tail gas flowmeter 12 can be linked with the first regulating valve 24, and the opening of the first regulating valve 24 is controlled by the flow signal.

[0045] After the original tail gas is pressurized by the liquid ring compressor 8, it enters the plug-in heat exchanger 4 in the tower body 1 through the shell side inlet 43, and the rich absorption oil cooling liquid enters the plug-in heat exchanger 4 through the tube side inlet 42. After the original tail gas and the rich absorption oil cooling liquid are cooled by the plug-in heat exchanger 4, a part of the volatile organic matter is condensed, flows into the liquid seal pipe 61 through the downcomer 6, and overflows to the bottom of the tower body 1 through the liquid seal pipe 61, which reduces the processing load of the absorption tower and saves the amount of absorption oil. The remaining gas phase (i.e., the intermediate tail gas) is deliquated by the coalescing deliquation filter element 52 and enters the upper part of the tower body 1 through the riser 5. The lean organic absorbent at room temperature is cooled by the refrigeration equipment 23 to form a lean organic absorbent cold liquid. The lean organic absorbent cold liquid is sprayed into the tower body through the absorbent distributor 2, and after countercurrent contact with the intermediate tail gas from the lower part of the tower body in the packing layer 3, the volatile organic matter in the intermediate tail gas is absorbed. The lean organic absorbent cold liquid absorbs the volatile organic matter to form a rich organic absorbent cold liquid. The organic absorbent-rich cold liquid is mixed with the volatile organic matter condensate overflowing to the bottom of the tower body and flows out from the bottom liquid outlet at the bottom of the tower body, enters the plug-in heat exchanger 4 again through the reflux pipe as a cooling medium to exchange heat with the original exhaust gas, enters the storage tank 10 from the pipe outlet 41, and is discharged through the external pump 9 for subsequent use.

[0046] When the volatile organic compound absorption tower provided by the utility model is actually used, the original tail gas needs to be pressurized by the liquid ring compressor 8 before entering the tower body 1, and then inserted into the heat exchanger 4 through the shell side inlet 43. Before heat exchange, a cold liquid rich in organic absorbent can be introduced into the inserted heat exchanger 4 in advance, and the cold liquid rich in organic absorbent enters the inserted heat exchanger 4 through the tube side inlet 42. After the original tail gas and the cold liquid rich in organic absorbent are heat exchanged by the inserted heat exchanger 4, the temperature of the original tail gas is reduced, and a part of the volatile organic matter in the original tail gas is condensed, and flows into the liquid seal pipe 61 through the downcomer 6, and overflows to the bottom of the tower body 1 through the liquid seal pipe 61, thereby reducing the processing load of the absorption tower and saving the amount of absorption oil. The remaining tail gas forms an intermediate tail gas, and the intermediate tail gas still contains some volatile organic matter that has not been removed. After the intermediate tail gas is deliquated by the coalescence and deliquation filter element 52, it enters the upper part of the tower body 1 through the riser 5. The lean organic absorbent at room temperature is cooled by the refrigeration facility to form lean organic absorbent cold liquid, which is sprayed to the packing layer 3 through the absorbent distributor 2. After countercurrent contact with the intermediate tail gas from the lower part in the packing layer 3, the remaining volatile organic matter in the intermediate tail gas is absorbed by the lean organic absorbent cold liquid. The lean organic absorbent cold liquid after absorbing the volatile organic matter forms a rich organic absorbent cold liquid. The rich organic absorbent cold liquid finally accumulates at the bottom of the tower body 1 and mixes with the volatile organic matter at the bottom of the overflow tower body 1. After passing through the reflux pipe 7, it enters the pipe side inlet 42 of the plug-in heat exchanger 4 again to exchange heat with the original tail gas. Finally, the rich organic absorbent enters the storage tank 10 from the pipe side outlet 41 and is discharged through the external pump 9 for subsequent use. By controlling the flow rate of the rich organic absorbent in the bypass pipe 71, the flow rate entering the pipe side inlet 42 of the plug-in heat exchanger 4 is indirectly controlled to adjust the temperature in the tower body 1 and maintain the temperature of the packing layer 3 unchanged. If the temperature of the packing layer 3 is stable, the absorption efficiency remains unchanged. The original tail gas is heat exchanged by the insert heat exchanger 4, and a part of the volatile organic matter is condensed in advance, which reduces the processing load of the absorption tower and saves the amount of organic absorbent. The volatile organic matter condensed in advance is discharged by the liquid seal pipe 61 to prevent the gas that has not been deliquated from entering the absorption tower through the downcomer 6. The coalescing deliquation filter element 52 is filled in the tail gas riser 5 to reduce the influence of the tail gas carrying liquid on the absorption effect of the packing layer 3. And the optimal gas-liquid ratio is guaranteed by controlling the flow ratio of the tail gas and the organic absorbent.

[0047] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "a specific implementation", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In the present invention, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0048] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the present invention.

[0049] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0050] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A volatile organic compound absorption tower, characterized in that: It comprises a tower body (1), wherein an absorbent distributor (2), a packing layer (3) and an inserted heat exchanger (4) are arranged in sequence from top to bottom in the tower body (1); The inserted heat exchanger (4) comprises a hollow shell-side portion and a hollow tube-side portion in contact with the shell-side portion, wherein a shell-side inlet (43), a gas phase outlet facing the packing layer (3), and a liquid phase outlet facing the bottom of the tower body (1) are arranged on the side wall of the shell-side portion, and a tube-side inlet (42) and a tube-side outlet (41) are arranged on the side wall of the tube-side portion, and the tube-side inlet (42) is connected to the liquid outlet at the bottom of the tower body (1).

2. The volatile organic compound absorption tower according to claim 1, characterized in that: The tower bottom liquid outlet is connected to the tube side inlet (42) via a reflux pipeline (7). A bypass pipeline (71) is provided on the side wall of the reflux pipeline (7). A second regulating valve (72) is provided on the bypass pipeline (71).

3. The volatile organic compound absorption tower according to claim 2, characterized in that: The tower body (1) is provided with a thermometer (11) for monitoring the temperature inside the tower body (1), and the thermometer (11) is electrically connected to the second regulating valve (72).

4. The volatile organic compound absorption tower according to any one of claims 1 to 3, characterized in that: A gas riser (5) is provided on the gas phase outlet, and the gas riser (5) extends towards the packing layer (3); a coalescing and deliquescence filter element (52) is provided in the gas riser (5).

5. The volatile organic compound absorption tower according to claim 4, characterized in that: A baffle (51) is provided on the inner wall of the tower body (1), the baffle (51) is placed above the riser (5), and the baffle (51) extends obliquely downward from the side wall of the tower body (1).

6. The volatile organic compound absorption tower according to any one of claims 1 to 3, characterized in that: A downcomer (6) is provided on the liquid phase outlet, and the downcomer (6) extends toward the bottom of the tower body (1).

7. The volatile organic compound absorption tower according to claim 6, characterized in that: A liquid sealing pipe (61) is provided below the downcomer (6), the liquid sealing pipe (61) being fixed on the inner wall of the tower body (1), and the end of the downcomer (6) extends into the liquid sealing pipe (61) to form an overflow structure.

8. The volatile organic compound absorption tower according to any one of claims 1 to 3, characterized in that: The absorbent distributor (2) comprises a liquid dispensing pipe (21), one end of the liquid dispensing pipe (21) being located outside the tower body (1) and the other end being inserted into the tower body (1), a portion of the liquid dispensing pipe (21) inserted into the tower body (1) being provided with a nozzle (22) facing the packing layer (3), and one end of the liquid dispensing pipe (21) being located outside the tower body (1) being connected to an absorbent feed pipe, and a first regulating valve (24) being provided on the absorbent feed pipe.

9. The volatile organic compound absorption tower according to claim 8, characterized in that: The tower body (1) is provided with an exhaust gas flow meter (12) for detecting the gas flow at the gas phase outlet, and the exhaust gas flow meter (12) is electrically connected to the first regulating valve (24).

10. A volatile organic compound absorption system, characterized in that: A volatile organic compound absorption tower comprising any one of claims 1 to 9.

11. The volatile organic compound absorption system according to claim 10, characterized in that: The tower bottom liquid outlet is connected to the tube side inlet (42) via a reflux pipe (7); the tube side outlet (41) and the side wall of the reflux pipe (7) are both connected to a tower bottom liquid storage tank (10); and the feed end of the absorbent distributor (2) is connected to a refrigeration device.

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