Temperature and pressure swing adsorption and desorption waste gas recovery system

Abstract

The utility model discloses a variable-temperature and variable-pressure adsorption and desorption waste gas recovery system, which belongs to the field of waste gas treatment and comprises an adsorption and desorption tower, the adsorption and desorption tower is of a double-layer structure with an inner cavity and an outer cavity which are mutually independent, and an adsorbent is arranged in the inner cavity; the adsorption and desorption tower is connected with a waste gas inlet pipe and a waste gas discharge pipe which are communicated with the inner cavity, the waste gas discharge pipe is connected with a main fan, and adsorption valves are mounted on the waste gas inlet pipe and the waste gas discharge pipe; the adsorption and desorption tower is connected with a nitrogen inlet pipe and a desorption pipe which are communicated with the inner cavity, a nitrogen valve is mounted on the nitrogen inlet pipe, a vacuum pump and a condenser are sequentially mounted on the desorption pipe in the airflow direction, and the condenser is further connected with a liquid storage tank; the adsorption and desorption tower is connected with a steam inlet pipe and a steam discharge pipe which are communicated with the outer cavity, and steam valves are mounted on the steam inlet pipe and the steam discharge pipe. According to the utility model, the desorption efficiency can be improved, and the adsorption efficiency can be improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to waste gas treatment technical field especially relates to a variable temperature and pressure adsorption desorption waste gas recovery system. BACKGROUND

[0002] With the continuous development of China's economy and the deep adjustment of industrial structure, clean production has become a deeply rooted development concept. We see that in recent years, China has been increasing the environmental regulation, especially the regulation and investment of industrial waste gas, and has achieved remarkable results. At present, organic solvents are needed in many industries, and some volatile organic compounds (VOCs) waste gas will be produced. For example, furniture manufacturing, metal processing, automobile production and maintenance, biological chemical industry and other enterprises, the waste gas treatment process and supporting equipment are also more, but due to the influence of investment operation cost, production status and other comprehensive factors, the process selected by each industry is also different.

[0003] Under the influence of double carbon policy, waste gas treatment equipment is required to develop towards low energy consumption, high efficiency and recyclability. How to further reduce energy consumption has become a problem that waste gas treatment equipment must face.

[0004] Adsorption method is a very good organic waste gas treatment process. The current mainstream method is to make the adsorbent have adsorption performance again by desorption regeneration, but the adsorbent is faced with the difficulty of adsorption saturation.

[0005] The current mainstream adsorption and desorption method is to use variable temperature adsorption and desorption: that is, adsorption at room temperature and desorption at high temperature. Some use variable pressure adsorption and desorption: that is, adsorption at normal pressure or high pressure and desorption under vacuum condition. But it is still rare to use variable temperature and pressure adsorption and desorption under variable temperature and pressure conditions, that is, adsorption at room temperature and normal pressure and desorption at high temperature and high vacuum condition.

[0006] Variable temperature and pressure adsorption and desorption can greatly improve the desorption efficiency, improve the treatment efficiency and recovery efficiency of VOCs, improve the cyclic adsorption capacity of adsorbent, and reduce the energy consumption and the amount of adsorbent. But there is no variable temperature and pressure adsorption and desorption equipment in the prior art, so it is urgent to design a variable temperature and pressure adsorption and desorption waste gas recovery system. SUMMARY

[0007] In view of the problem that the prior art lacks an equipment capable of adsorbing at room temperature and normal pressure and desorbing at high temperature and high vacuum condition, the purpose of the utility model is to provide a variable temperature and pressure adsorption and desorption waste gas recovery system, so as to at least partially solve the above problems.

[0008] To achieve the above purpose, the technical scheme of the utility model is:

[0009] A temperature and pressure swing adsorption desorption waste gas recovery system, comprising an adsorption desorption tower, the adsorption desorption tower is a double-layer structure with independent inner cavity and outer cavity, and an adsorbent is arranged in the inner cavity;

[0010] The adsorption desorption tower is connected with a waste gas inlet pipe and a waste gas outlet pipe which are communicated with the inner cavity of the adsorption desorption tower, and the waste gas outlet pipe is connected with a main fan, and adsorption valves are installed on the waste gas inlet pipe and the waste gas outlet pipe;

[0011] The adsorption desorption tower is connected with a nitrogen inlet pipe and a nitrogen outlet pipe which are communicated with the inner cavity, and nitrogen valves are installed on the nitrogen inlet pipe and the nitrogen outlet pipe;

[0012] The adsorption desorption tower is connected with a desorption pipe which is communicated with the inner cavity, and a vacuum pump and a condenser are installed on the desorption pipe in sequence along the gas flow direction, and the condenser is further connected with a liquid storage tank;

[0013] The adsorption desorption tower is connected with a steam inlet pipe and a steam outlet pipe which are communicated with the outer cavity, and steam valves are installed on the steam inlet pipe and the steam outlet pipe.

[0014] In some preferred embodiments, the adsorption desorption tower has two or more and is connected in parallel.

[0015] In some preferred embodiments, the waste gas inlet pipe connected to each adsorption desorption tower is connected to a main waste gas pipe, and the main waste gas pipe is used to connect a waste gas source; the exhaust end of the condenser is connected to the main waste gas pipe through a gas return pipeline, and a gas return valve is installed on the gas return pipeline.

[0016] In some preferred embodiments, the nitrogen outlet pipe connected to each adsorption desorption tower is connected to the main waste gas pipe, and a nitrogen valve is installed on the nitrogen outlet pipe.

[0017] In some preferred embodiments, the adsorption desorption tower is fixed with a cooling air inlet pipe and a cooling air outlet pipe which are communicated with the outer cavity, a cooling fan is installed on the cooling air inlet pipe, and cooling air valves are installed on the cooling air inlet pipe and the cooling air outlet pipe.

[0018] In some preferred embodiments, a heat exchanger is further included, and the exhaust end of the heat exchanger is connected to the cooling air inlet pipe.

[0019] In some preferred embodiments, the heat exchanger and the condenser share the same cooling medium.

[0020] In some preferred embodiments, a nitrogen branch pipe is further connected to the nitrogen inlet pipe, and a vacuum breaking valve is installed on the nitrogen branch pipe.

[0021] The beneficial effect of the present application lies in that adsorption is carried out under normal temperature and pressure, and desorption is carried out under high temperature and high vacuum condition, so that the desorption efficiency is improved, the higher the desorption efficiency is, the higher the utilization efficiency of adsorbent adsorption capacity is, and the adsorption efficiency is also higher; the desorption is carried out under vacuum state, so that the safety of the system is greatly improved; when the desorption gas under vacuum condition is discharged into normal pressure environment, the volume is contracted, so that the concentration is increased, which greatly improves the condensation efficiency, and reduces the condensation energy consumption. BRIEF DESCRIPTION OF DRAWINGS

[0022] Fig. 1 It is a structural schematic diagram of the present application.

[0023] Fig. 2 It is a nitrogen gas circuit schematic diagram of the present application.

[0024] In the figure: 1-adsorption and desorption tower, 101-waste gas inlet pipe, 102-waste gas outlet pipe, 103-adsorption valve, 104-main waste gas pipe, 105-main exhaust pipe, 106-nitrogen gas inlet pipe, 1061-nitrogen gas outlet pipe, 107-desorption pipe, 108-nitrogen gas valve, 109-nitrogen gas main inlet pipe, 110-desorption valve, 111-main desorption pipe, 112-branch pipe, 113-vacuum breaking valve, 114-steam inlet pipe, 115-steam outlet pipe, 116-steam valve, 117-steam main inlet pipe, 118-cooling air inlet pipe, 119-cooling air valve, 120-main cooling air pipe, 121-water inlet pipe, 122-water inlet valve, 123-main water pipe, 124-gas return pipe, 125-gas return valve; 2-main fan, 3-vacuum pump, 4-condenser, 5-liquid storage tank, 6-cooling fan, 7-heat exchanger. DETAILED DESCRIPTION

[0025] The specific embodiments of the present application will be further described below in combination with the drawings. It should be noted that the description of these embodiments is used to help understand the present application, but does not constitute a limitation on the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0026] It should be noted that in the description of the present application, the terms "upper", "lower", "left", "right", "front", "back" and the like indicate the orientation or positional relationship of the structure of the present application shown in the drawings, and are only for the convenience of describing the present application simply, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the present application.

[0027] For the "first" and "second" in the technical solution, it is only a distinction for the same or similar structure, or the corresponding structure with similar functions, and it is not the arrangement of the importance of these structures, nor the order, or the comparison of size, or other meanings.

[0028] In addition, unless otherwise explicitly specified and limited, the terms "mounting", "connection" should be understood broadly, for example, the connection can be fixed connection, or detachable connection, or integrally connected; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through intermediate medium, can be the communication inside two structures. For those skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the overall idea of the utility model and the specific situation of the scheme.

[0029] Embodiment

[0030] A variable temperature and pressure adsorption desorption waste gas recovery system, as shown in Figs. 1-2 The adsorption and desorption tower 1 is of double-layer structure with mutually independent inner cavity and outer cavity, and the adsorbent is arranged in the inner cavity, and the outer cavity is located outside the inner cavity, and there is a certain gap between the two.

[0031] In the embodiment, the adsorption and desorption tower 1 is provided with two and arranged in parallel, so as to alternately use the two adsorption and desorption towers 1.

[0032] The adsorption and desorption tower 1 is connected with the waste gas inlet pipe 101 and the waste gas outlet pipe 102 which are communicated with the inner cavity thereof, and the adsorption valve 103 is arranged on the waste gas inlet pipe 101 and the waste gas outlet pipe 102, and the adsorption valve 103 is used for controlling the on-off state of the pipeline, for example, a gate valve, which is usually configured as an electric valve, a solenoid valve or a pneumatic valve suitable for control. The two waste gas inlet pipes 101 are arranged in parallel, and are connected to the main waste gas pipe 104, which is used for connecting the waste gas source. The two waste gas outlet pipes 102 are arranged in parallel, and are connected to the main exhaust pipe 105, and the end of the main exhaust pipe 105 is connected with the main fan 2.

[0033] The adsorption and desorption tower 1 is connected with the nitrogen inlet pipe 106 and the nitrogen outlet pipe 1061 which are communicated with the inner cavity thereof, and the nitrogen valve 108 is arranged on the nitrogen inlet pipe 106, and the nitrogen valve 108 is used for controlling the on-off state of the pipeline, for example, a gate valve, which is usually configured as an electric valve, a solenoid valve or a pneumatic valve suitable for control. The two nitrogen inlet pipes 106 are arranged in parallel, and are connected to the nitrogen main inlet pipe 109, which is used for connecting the nitrogen source, and the nitrogen main inlet pipe 109 is also provided with a nitrogen valve 108, so as to control the on-off state of the nitrogen.

[0034] Both nitrogen exhaust pipes 1061 are connected to the main exhaust pipe 104, and nitrogen valves 108 are installed on both nitrogen exhaust pipes 1061, which are used to control the on-off state of the pipeline, such as gate valves, and are usually configured as electric valves, solenoid valves or pneumatic valves suitable for control.

[0035] Both adsorption and desorption towers 1 are connected with desorption pipes 107 which are in communication with the inner cavities of the towers. Desorption valves 110 are installed on the desorption pipes 107, and the two desorption pipes 107 are arranged in parallel and connected to a main desorption pipe 111. The main desorption pipe 111 is sequentially provided with a vacuum pump 3 and a condenser 4 along the direction of gas flow. The condenser 4 is arranged vertically, with its gas inlet end at a lower position, and the gas inlet end is connected to the liquid inlet end of a liquid storage tank 5 at a lower position through a pipeline. The gas outlet end of the condenser 4 is at a higher position.

[0036] It is easy to understand that both adsorption and desorption towers 1 are connected with branch pipes 112 which are in communication with the inner cavities of the towers. Break vacuum valves 113 are installed on the branch pipes 112 to break the vacuum in the inner cavities. Usually, the two ends of the branch pipe 112 are connected between the adsorption and desorption towers 1 and the nitrogen main inlet pipe 109, i.e. the branch pipe 112 is arranged in parallel with the nitrogen inlet pipe 106, and a nitrogen valve 108 is also installed on the branch pipe 112 to prevent nitrogen leakage during break vacuum.

[0037] Both adsorption and desorption towers 1 are connected with steam inlet pipes 114 and steam exhaust pipes 115 which are in communication with the outer cavities of the towers. Steam valves 116 are installed on the steam inlet pipes 114 and the steam exhaust pipes 115, which are used to control the on-off state of the pipeline, such as gate valves, and are usually configured as electric valves, solenoid valves or pneumatic valves suitable for control. The two steam inlet pipes 114 are arranged in parallel and connected to a steam main inlet pipe 117, which is used to connect a steam source. A steam valve 116 is also installed on the steam main inlet pipe 117 to control the on-off state of the steam.

[0038] Both adsorption and desorption towers 1 are connected with cooling air inlet pipes 118 and cooling air exhaust pipes which are in communication with the outer cavities of the towers. Cooling air valves 119 are installed on the cooling air inlet pipes 118 and the cooling air exhaust pipes, which are used to control the on-off state of the pipeline, such as gate valves, and are usually configured as electric valves, solenoid valves or pneumatic valves suitable for control. The two cooling air inlet pipes 118 are arranged in parallel and connected to a main cooling air pipe 120, on which a cooling air fan 6 is installed. It is easy to understand that because the use of steam and the use of cooling air do not coincide, the cooling air exhaust pipe can be shared with the steam exhaust pipe 115, and the corresponding valves are also shared.

[0039] Also included is a heat exchanger 7, the outlet port of which is connected to the cooling air inlet pipe 118, the heat exchanger 7 sharing the same cooling medium, such as chilled water, with the condenser 4. The water inlet pipe 121 is connected to the water inlet port of the heat exchanger 7 and the water inlet port of the condenser 4, and a water inlet valve 122, such as a gate valve, is installed on the water inlet pipe 121 to control the on-off state of the pipeline. The two water inlet pipes 121 are arranged in parallel and are connected to the main water pipe 123, which is used to connect to the cooling source. The water inlet valve 122 is also installed on the main water pipe 123 to control the on-off state of the cooling medium.

[0040] The working process of the temperature and pressure swing adsorption and desorption waste gas recovery system provided in the embodiments of the present application is as follows:

[0041] 1. Adsorption in the A tower: open the adsorption valves 103 on the waste gas inlet pipe 101 and the waste gas outlet pipe 102 belonging to the A tower, close the valves on other pipelines connected to the A tower, and open the main air blower 2. The waste gas enters the inner cavity of the A tower through the waste gas inlet pipe 101, and the volatile organic compounds (VOCs) in the waste gas are adsorbed by the adsorbent. Then the waste gas is discharged by the main air blower 2 through the waste gas outlet pipe 102, until the adsorbent is saturated, and then the A tower enters the next step.

[0042] 2. Nitrogen purge and replacement in the A tower: open the nitrogen valves 108 on the nitrogen inlet pipe 106 and the nitrogen outlet pipe 1061 belonging to the A tower, open the nitrogen valve 108 on the main nitrogen inlet pipe 109, and close the valves on other pipelines connected to the A tower. The nitrogen source continuously enters the inner cavity of the A tower, and the residual waste gas in the inner cavity of the A tower is discharged into the main waste gas pipe 104 (into another adsorption and desorption tower) through the nitrogen gas, and then the A tower enters the next step.

[0043] 3. Desorption in the A tower: open the steam valves 116 on the steam inlet pipe 114 and the steam outlet pipe 115 belonging to the A tower, open the steam valve 116 on the main steam inlet pipe 117, open the nitrogen valves 108 on the desorption pipe 107 belonging to the A tower and the main desorption pipe 111, open the water inlet valves 122 on the water inlet pipe 121 belonging to the condenser 4 and the main water pipe 123, close the valves on other pipelines connected to the A tower, and finally open the vacuum pump 3. During desorption, the steam source continuously enters the outer cavity of the A tower, indirectly heating the inner cavity of the A tower to provide the required temperature for desorption, and the vacuum pump 3 provides the required vacuum degree for the desorption of the adsorbent in the inner cavity, so that the volatile organic compounds (VOCs) adsorbed in the adsorbent are released. The mixed gas encounters cold when passing through the condenser 4, so that the volatile organic compounds (VOCs) in the mixed gas are condensed and liquefied, and collected in the liquid storage tank 5. When there is no liquid flowing into the liquid storage tank 5, the desorption is completed, and the A tower enters the next step.

[0044] 4. A tower break vacuum: open the break vacuum valve 113 on the branch pipe 112, so that the inner cavity of the A tower returns to normal pressure, and then close the break vacuum valve 113.

[0045] 5. A tower cooling: open the cooling air valve 119 on the cooling air inlet pipe 118 to which the A tower belongs, additionally open the water inlet valve 122 on the water inlet pipe 121 connected with the heat exchanger 7, and open the water inlet valve 122 on the main water pipe 123, and close the valves on other pipes connected with the A tower. Open the cooling fan 6, and the cold air source continuously takes away the heat in the inner cavity of the A tower, until the adsorbent in the inner cavity of the A tower is cooled, and then the above steps can be repeated. It is easy to understand that before the cooling air is passed, the inner cavity can also be preliminarily cooled by nitrogen, that is, open the nitrogen valve 108 on the nitrogen inlet pipe 106 to which the A tower belongs, and simultaneously open the nitrogen valve 108 on the main nitrogen inlet pipe 109, and close the valves on other pipes connected with the A tower, and the nitrogen source continuously enters the inner cavity of the A tower, and the residual volatile organic compounds (VOCs) in the inner cavity of the A tower are taken away by the nitrogen, and part of the heat in the inner cavity of the A tower can also be taken away.

[0046] The above process is alternately performed by the A tower and the B tower, that is, the A tower performs the adsorption process while the B tower performs the desorption process, and vice versa, and the alternation is repeated.

[0047] It is easy to understand that the exhaust end of the condenser 4 is also connected to the main exhaust pipe 104 through a gas return pipeline 124, and a gas return valve 125 is installed on the gas return pipeline 124. In this way, when the A tower performs the desorption process, the gas return valve 125 on the gas return pipeline 124 is opened, so that the exhaust gas discharged from the condenser 4 flows into the B tower, and at this time the B tower is in the adsorption process. Conversely, when the B tower desorbs, the exhaust gas discharged from the condenser 4 flows into the A tower which is in the adsorption process.

[0048] It is easy to understand that the adsorption and desorption tower 1 can only have one, and the corresponding main exhaust pipe 104, main exhaust pipe 105, main nitrogen inlet pipe 109, main desorption pipe 111, main steam inlet pipe 117, main cooling air pipe 120, main water pipe 123 and gas return pipeline 124 can be omitted, and the valves on these pipelines can also be omitted.

[0049] The embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited to the described embodiments. For those skilled in the art, various changes, modifications, replacements and modifications can be made to these embodiments without departing from the principles and spirits of the present application, and still fall within the protection scope of the present application.

Claims

1. A temperature swing pressure swing adsorption desorption exhaust gas recovery system characterized by: The adsorption and desorption tower comprises an adsorbent arranged in an inner cavity of the adsorption and desorption tower with a double-layer structure having the inner cavity and an outer cavity independent of each other; The adsorption and desorption tower is connected with a waste gas inlet pipe and a waste gas outlet pipe in communication with the inner cavity, the waste gas outlet pipe is connected with a main fan, and adsorption valves are arranged on the waste gas inlet pipe and the waste gas outlet pipe; The adsorption and desorption tower is connected with a nitrogen inlet pipe and a nitrogen outlet pipe in communication with the inner cavity, and nitrogen valves are arranged on the nitrogen inlet pipe and the nitrogen outlet pipe; The adsorption and desorption tower is connected with a desorption pipe in communication with the inner cavity, a vacuum pump and a condenser are arranged on the desorption pipe in sequence along the direction of air flow, and the condenser is further connected with a liquid storage tank; The adsorption and desorption tower is connected with a steam inlet pipe and a steam outlet pipe in communication with the outer cavity, and steam valves are arranged on the steam inlet pipe and the steam outlet pipe.

2. The system of claim 1, wherein: The adsorption and desorption tower has two or more and is connected in parallel.

3. The system of claim 2, wherein: The waste gas inlet pipes connected with the adsorption and desorption towers are connected with a main waste gas pipe, the main waste gas pipe is used for connecting a waste gas source, the exhaust end of the condenser is connected with the main waste gas pipe through a gas return pipeline, and a gas return valve is arranged on the gas return pipeline.

4. The system of claim 3, wherein: The nitrogen outlet pipes connected with the adsorption and desorption towers are connected with the main waste gas pipe, and nitrogen valves are arranged on the nitrogen outlet pipes.

5. The system of claim 1, wherein: Cooling air inlet pipes and cooling air outlet pipes in communication with the outer cavity are fixed on the adsorption and desorption tower, a cooling fan is arranged on the cooling air inlet pipe, and cooling air valves are arranged on the cooling air inlet pipe and the cooling air outlet pipe.

6. The system of claim 5, wherein: A heat exchanger is further arranged, and the exhaust end of the heat exchanger is connected with the cooling air inlet pipe.

7. The system of claim 6, wherein: The heat exchanger and the condenser share the same cooling medium.

8. The temperature swing pressure swing adsorption desorption exhaust gas recovery system of claim 1, wherein: A nitrogen branch pipe is further connected with the nitrogen inlet pipe, and a vacuum breaking valve is arranged on the nitrogen branch pipe.

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