Adsorption and desorption device for treating waste gas containing difficult-to-desorb VOCs (Volatile Organic Compounds)

Abstract

The utility model relates to the technical field of adsorption and desorption in treatment of waste gas containing difficult-to-desorb VOCs (Volatile Organic Compounds), and discloses an adsorption and desorption device for treatment of waste gas containing difficult-to-desorb VOCs, which comprises an adsorption and desorption tank, a top filter layer, a heat exchange tube, an adsorption main body, a bottom filter layer, a heat preservation water tank and an air energy refrigerating and heating dual-purpose system, the adsorption main body and the heat exchange pipe are arranged on the inner side of a tank body of the adsorption and desorption tank, the heat exchange pipe is connected with the heat preservation water tank through a pipeline, and the heat preservation water tank is connected with the air energy refrigerating and heating dual-purpose system through a pipeline. According to the utility model, adsorption and desorption can be kept efficient and stable for a long time, the adsorption main body is convenient to replace, the unique internal structure of the tank body can enable the adsorption main body to be cooled and heated uniformly, the adsorption efficiency is high, and the desorption effect is thorough, so that the problems that the adsorption and desorption effect of waste gas containing difficult-to-desorb VOCs cannot stably and efficiently reach the standard for a long time and the adsorbent is frequently replaced are solved; the adsorbent even does not need to be replaced, and pollution reduction and carbon reduction are synchronously carried out.

Description

Technical Field

[0001] This utility model relates to the field of adsorption and desorption technology for treating waste gas containing difficult-to-desorb VOCs, and in particular to an adsorption and desorption device for treating waste gas containing difficult-to-desorb VOCs. Background Technology

[0002] Organic solvents commonly used in the pharmaceutical and chemical industries, such as alcohols, ethers, chloroform, petroleum ether, diethyl ether, petroleum dewaxing solvents, metal cleaning agents, paint removers, organic extractants, refrigerants, and polyurethane foaming agents, are easily lost during actual use and readily enter the atmosphere as VOCs, causing air pollution. Furthermore, because they tend to accumulate in organisms, they possess certain carcinogenic and genotoxic properties, posing health risks with prolonged exposure. Therefore, timely treatment is necessary. Adsorption-desorption is a significant component of the processes used to treat these VOCs. However, due to the complex composition, high boiling points, or significant influence of external environmental changes, these VOCs are difficult to desorb completely and tend to accumulate in the adsorbent, thus affecting adsorption and desorption efficiency. Therefore, efficient and stable treatment of these difficult-to-desorb VOCs is crucial.

[0003] A search revealed a Chinese patent publication number (CN218742018U) disclosing a vacuum desorption treatment device for materials containing organic pollutants. This device includes a vacuum desorption tower filled with the material to be treated, a vacuum pump, a condenser, a storage tank, and a heating system. The top and bottom of the vacuum desorption tower are respectively equipped with a loading pipe and a unloading pipe, both fitted with valves. Desorption ports are located on the side walls of the vacuum desorption tower, connected to the inlet of the vacuum pump via desorption pipes. The outlet of the vacuum pump is connected to the inlet of the condenser, which is also connected to the storage tank. The heating system is connected to the vacuum desorption tower to heat the material. Although this device combines heating with vacuum negative pressure to improve desorption efficiency and effectively reduce desorption temperature while adjusting the vacuum level to a safe desorption range, it only performs desorption and lacks adsorption capabilities, making its performance limited and its practicality in the field of waste gas treatment somewhat one-sided.

[0004] Existing adsorption-desorption technologies and devices have various limitations for treating waste gases containing difficult-to-desorb VOCs. These limitations include: complex and cumbersome design and operation; inability to maintain high and stable adsorption-desorption efficiency over a long period; frequent replacement of the adsorbent substrate; large footprint of the entire device; ineffective cyclical coordination between adsorption and desorption efficiencies; and secondary pollution to the environment. Therefore, there is an urgent need to research and develop new adsorption-desorption devices for treating waste gases containing difficult-to-desorb VOCs that can solve or avoid the above problems. Utility Model Content

[0005] To overcome the above shortcomings, this utility model provides an adsorption and desorption device for treating waste gas containing difficult-to-desorb VOCs, aiming to improve the problems in the existing technology where the adsorption efficiency and desorption efficiency cannot be effectively coordinated, causing secondary pollution to the environment, and the adsorption and desorption effect of waste gas containing difficult-to-desorb VOCs cannot be consistently and efficiently achieved in the long term.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An adsorption-desorption device for treating waste gas containing difficult-to-desorb VOCs includes an adsorption-desorption tank, a top filter layer, a heat exchange tube, an adsorption body, a bottom filter layer, an insulated water tank, and an air-source heat pump system. The adsorption body and the heat exchange tube are disposed inside the adsorption-desorption tank. The heat exchange tube is connected to the insulated water tank via a pipe. The insulated water tank is connected to the air-source heat pump system via a pipe. The top filter layer and the bottom filter layer are respectively disposed in the upper and lower parts of the adsorption-desorption tank.

[0008] Moreover, the adsorption-desorption tank has various shapes, including cylindrical, spherical, and cubic, and can be vertical or horizontal.

[0009] Moreover, the top filter layer and the bottom filter layer are made of one or more of the following materials: fixed ceramic rings, maifan stone, volcanic rock, zeolite, etc.

[0010] Moreover, the heat exchange tubes are made of copper, stainless steel, aluminum alloy, etc., and come in various styles such as straight tubes, horizontal tubes, or cross-shaped tube networks, and are evenly distributed in a linear array in the adsorption-desorption tank.

[0011] Furthermore, the adsorption body is provided with a support frame inside, and a core adsorption disk is provided inside the adsorption body.

[0012] Moreover, the adsorption body is composed of the supporting skeleton and the core adsorption disk, and the styles include umbrella-shaped, pleated inclined sand wall-shaped, column-shaped, grid-shaped, block-shaped and other types.

[0013] Moreover, the supporting framework and the core adsorption disk are made of one or more of the following materials: fixed activated carbon particles, activated carbon fibers, molecular sieves, silica gel, metal-organic frameworks, etc.

[0014] Moreover, the air-source heat pump system has both cooling and heating functions, providing cold water during adsorption and hot water during desorption, respectively.

[0015] This utility model has the following beneficial effects:

[0016] 1. This utility model is simple to design and operate. The core component that performs the main function is the adsorption body, which consists of a support frame and a core adsorption disk. The support frame and the core adsorption disk are stacked, and the number of stacks is determined according to the treatment scale of the waste gas containing difficult-to-desorb VOCs. This not only makes the whole set of equipment occupy a small area, but also makes it easy to replace the adsorption body and the adsorbent replacement time is long or even unnecessary. Thus, it can achieve precise adsorption with the most optimized investment and operating costs for waste gas containing difficult-to-desorb VOCs.

[0017] 2. By setting up a top filter layer and a bottom filter layer, this utility model can not only filter out components such as moisture and dust in waste gas containing difficult-to-desorb VOCs, making the waste gas entering the adsorption-desorption tank cleaner and not adversely affecting the adsorption-desorption process, but also ensure that the waste gas containing difficult-to-desorb VOCs enters and exits the adsorption-desorption tank evenly, ensuring that the adsorption body fully adsorbs and desorbs the waste gas containing difficult-to-desorb VOCs, avoiding flow deviation and sidewall effects, and thus avoiding affecting the overall adsorption-desorption effect.

[0018] 3. The unique internal structure of the tank in this utility model not only ensures uniform cooling and heating of the adsorption body, achieving a regular distribution of the adsorption body, but also utilizes an air-source dual-purpose cooling and heating system. This system can both cool and provide cold water to the heat exchange tubes to maintain adsorption efficiency, and heat and provide hot water to the heat exchange tubes to maintain desorption efficiency. Furthermore, this system requires no gas and is not limited by sunlight; it can achieve cooling and heating as long as there is air, and there are no exhaust emissions, achieving environmental protection and energy saving.

[0019] In summary, this utility model features simple design and operation, maintains high efficiency and stability in adsorption and desorption over a long period, facilitates easy replacement of the adsorption body, minimizes adsorbent replacement intervals, has a small footprint, and its unique internal tank structure ensures uniform heating and cooling of the adsorption body, resulting in high adsorption efficiency and thorough desorption. It also boasts low investment and operating costs. Furthermore, it solves the problems of inconsistent and efficient adsorption and desorption of difficult-to-desorb VOCs-containing waste gas, as well as frequent adsorbent replacements. Moreover, it is environmentally friendly and energy-saving, does not generate secondary pollution, and the adsorbent may not even need to be replaced, thus achieving simultaneous pollution reduction and carbon reduction. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the main body of an adsorption-desorption device for treating waste gas containing difficult-to-desorb VOCs, as proposed in this utility model.

[0021] Figure 2 This is a schematic diagram of the support frame structure of an adsorption-desorption device for treating waste gas containing difficult-to-desorb VOCs, as proposed in this utility model.

[0022] Legend:

[0023] 1. Adsorption-desorption tank; 2. Top filter layer; 3. Heat exchange tube; 4. Adsorption body; 41. Support frame; 42. Core adsorption plate; 5. Bottom filter layer; 6. Insulated water tank; 7. Air source heat pump system for both cooling and heating. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0025] Reference Figure 1 and Figure 2 This utility model provides an embodiment of an adsorption-desorption device for treating waste gas containing difficult-to-desorb VOCs, comprising an adsorption-desorption tank 1, a top filter layer 2, a heat exchange tube 3, an adsorption body 4, a bottom filter layer 5, an insulated water tank 6, and an air-source heat pump system 7. The adsorption body 4 and the heat exchange tube 3 are disposed inside the tank of the adsorption-desorption tank 1. The heat exchange tube 3 is connected to the insulated water tank 6 via a pipe, and the insulated water tank 6 is connected to the air-source heat pump system 7 via a pipe. The top filter layer 2 and the bottom filter layer 5 are respectively disposed in the upper and lower parts of the adsorption-desorption tank 1. The tank body of the adsorption-desorption tank 1 includes various types such as cylindrical, spherical, and cubic, and can be vertical or horizontal. The materials of the 2 and bottom filter layer 5 are one or more of the following: fixed ceramic rings, maifan stone, volcanic rock, zeolite, etc. The material of the heat exchange tube 3 is one of the following: copper, stainless steel, aluminum alloy, etc. The styles include straight tubes, horizontal tubes or cross-pipe networks, etc., and they are evenly distributed in a linear array in the adsorption-desorption tank 1. The adsorption body 4 is provided with a support frame 41 inside, and the adsorption body 4 is provided with a core adsorption plate 42 inside. The materials of the support frame 41 and the core adsorption plate 42 are one or more of the following: fixed activated carbon particles, activated carbon fibers, molecular sieves, silica gel, metal organic framework, etc. The air source cooling and heating dual-purpose system 7 has cooling and heating functions, which are used to provide cold water during adsorption and hot water during desorption, respectively.

[0026] Specifically, the waste gas containing difficult-to-desorb VOCs first enters the adsorption-desorption tank 1 for adsorption treatment. Since adsorption is an exothermic process, the temperature of the adsorbent 4 gradually decreases during adsorption, leading to a reduction in adsorption efficiency. To maintain a high-efficiency and stable adsorption effect, the air-source heat pump system 7 is activated at this time to perform cooling operation, ensuring that the ambient temperature of the adsorption-desorption tank 1 is kept within a suitable range. This cooling system circulates cold water into the equipment through heat exchange tubes 3, quickly removing the heat generated by the equipment, thereby reducing the temperature inside the adsorption-desorption tank 1. The heat exchange tubes 3 are usually made of high thermal conductivity materials, such as copper or aluminum alloys, which can efficiently conduct heat and ensure precise and effective temperature control of the system. When the adsorption process is completed and the adsorbent 4 reaches saturation, the desorption stage begins. At this time, nitrogen is used to assist desorption. Nitrogen reduces the temperature of the adsorbent 4 material. The adsorption force of the surface-adsorbed, difficult-to-desorb VOCs helps the desorption process proceed smoothly. During desorption, the temperature will rise because desorption is an endothermic process. In order to maintain a stable desorption effect and avoid the temperature rising too quickly and affecting the desorption efficiency, the air source heat pump system 7 is restarted to start heating. Hot water circulates into the system through the heat exchange pipe 3, raising the temperature of the adsorption-desorption tank 1 and helping the difficult-to-desorb VOCs to be successfully desorbed from the adsorption material. During the desorption process, the water volume in the insulated water tank 6 will decrease to a certain extent due to heat consumption. Therefore, it is replenished by water from the plant's public works to ensure that the water volume in the insulated water tank 6 is kept within a stable range and to maintain the good operation of the system. The design of the insulated water tank 6 ensures that the water temperature does not fluctuate rapidly during circulation, so as to minimize temperature fluctuations during the desorption process and improve overall efficiency.

[0027] Working Principle: When using this adsorption-desorption device, the pre-treated waste gas containing difficult-to-desorb VOCs first enters the adsorption-desorption tank 1 from the bottom for adsorption treatment. It first passes through the bottom filter layer 5 and then evenly enters the adsorption body 4. From bottom to top, it passes through layers of support frames 41 and core adsorption plates 42, allowing the adsorption body 4 to comprehensively adsorb the waste gas containing difficult-to-desorb VOCs. Afterward, it passes evenly through the top filter layer 2, and the fully adsorbed exhaust gas meets emission standards. The number of support frames 41 and core adsorption plates 42 is determined according to the treatment scale of the waste gas containing difficult-to-desorb VOCs, ensuring cost-optimized and precise adsorption. Since adsorption is an exothermic process, the temperature of the adsorption body 4 decreases during adsorption, while the ambient temperature increases. At this time, the air-source heat pump system 7 (for both cooling and heating) is activated. Cooling operation is performed to ensure that the heat exchange tube 3 is always filled with cold water in order to reduce the ambient temperature of the adsorption-desorption tank 1 and maintain high and stable adsorption efficiency. When desorption is performed after adsorption saturation, nitrogen is used to assist. Afterwards, the desorbed gas with a high concentration is further treated. Since desorption is an endothermic process, the temperature of the adsorption body 4 rises and the ambient temperature drops during desorption. In order to ensure that the desorption rate of the waste gas containing difficult-to-desorb VOCs does not change significantly within a certain period of time, the air-source cooling and heating dual-purpose system 7 operates in heating mode to ensure that the heat exchange tube 3 is always filled with hot water in order to raise the ambient temperature of the adsorption-desorption tank 1 and maintain high and stable desorption efficiency. If there is a certain amount of water loss in the insulated water tank 6, it is replenished by water from the plant's public works to ensure that the water in the insulated water tank 6 is maintained within a sustainable circulation range.

[0028] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An adsorption-desorption device for treating waste gas containing difficult-to-desorb VOCs, comprising an adsorption-desorption tank (1), a top filter layer (2), a heat exchange tube (3), an adsorption body (4), a bottom filter layer (5), an insulated water tank (6), and an air-source cooling and heating dual-purpose system (7), characterized in that: The adsorption body (4) and heat exchange tube (3) are disposed inside the adsorption-desorption tank (1). The heat exchange tube (3) is connected to the insulated water tank (6) through a pipe. The insulated water tank (6) is connected to the air-source cooling and heating dual-purpose system (7) through a pipe. The top filter layer (2) and the bottom filter layer (5) are respectively disposed in the upper and lower parts of the adsorption-desorption tank (1).

2. The adsorption and desorption device for treating waste gas containing hard-to-desorb VOCs according to claim 1, characterized in that: The adsorption-desorption tank (1) has a tank shape including cylindrical, spherical, and cubic, and its form includes vertical and horizontal.

3. The adsorption and desorption device for treating waste gas containing hard-to-desorb VOCs according to claim 1, characterized in that: The top filter layer (2) and the bottom filter layer (5) are both made of one of the following materials: fixed ceramic ring, maifan stone, volcanic rock, or zeolite.

4. The adsorption and desorption device for treating waste gas containing hard-to-desorb VOCs according to claim 1, characterized in that: The heat exchange tube (3) is made of copper, stainless steel or aluminum alloy, and its style includes straight tube, horizontal tube or cross tube network, and it is evenly distributed in a straight array in the adsorption-desorption tank (1).

5. The adsorption and desorption device for treating waste gas containing hard-to-desorb VOCs according to claim 1, characterized in that: The adsorption body (4) is provided with a support frame (41) inside, and the adsorption body (4) is provided with a core adsorption disk (42) inside.

6. The adsorption and desorption device for treating waste gas containing hard-to-desorb VOCs according to claim 5, characterized in that: The adsorption body (4) is composed of the supporting frame (41) and the core adsorption disk (42), and the styles include umbrella-shaped, pleated inclined sand wall-shaped, column-shaped, grid-shaped and block-shaped.

7. The adsorption and desorption device for treating waste gas containing hard-to-desorb VOCs according to claim 6, characterized in that: The supporting skeleton (41) and the core adsorption disk (42) are both made of one of the following materials: fixed activated carbon particles, activated carbon fibers, molecular sieves, silica gel, and metal-organic framework.

8. The adsorption and desorption device for treating waste gas containing hard-to-desorb VOCs according to claim 1, characterized in that: The air-source heat pump system (7) has both cooling and heating functions, and is used to provide cold water during adsorption and hot water during desorption.

Images