Heater-free efficient cold-drying adsorption type dryer and drying method

Abstract

The invention relates to the technical field of dryers, in particular to a heater-free efficient cold-drying adsorption type dryer and a drying method.The efficient cold-drying adsorption type dryer comprises a heat exchange system and two drying towers, the two drying towers are connected in parallel through a connecting pipeline, and the heat exchange system comprises a heating cylinder and a cooling cylinder; heat exchangers are arranged in the heating cylinder and the cooling cylinder, the two heat exchangers are connected in series through a heat exchange pipeline, a compressor and an expansion joint are arranged on the heat exchange pipeline, the compressor is used for compressing a refrigerant in the heat exchange pipeline into high-temperature and high-pressure gas from low-temperature and low-pressure gas, and the expansion joint is used for converting normal-temperature and high-pressure liquid into low-temperature and low-pressure liquid; and the heat exchanger in the heating cylinder radiates heat to heat the dried compressed air, and the heat exchanger in the cooling cylinder absorbs heat to refrigerate the to-be-dried compressed air. The heating energy efficiency ratio of the compressor is about 1: 3, and compared with a heater, a large amount of heating energy consumption can be saved.

Description

Technical Field

[0001] The invention relates to the technical field of dryers, and in particular to a heater-free high-efficiency cold-drying adsorption dryer and a drying method. Background Art

[0002] like Figure 1 As shown, the existing dust removal air compressor dryer includes two drying towers 1, namely Tower A and Tower B, desiccant is set in Tower A and Tower B, the bottom of Tower A and Tower B are connected with exhaust water inlet pipe and air inlet pipe 2, 3# pneumatic valve 14 and 4# pneumatic valve 15 are set on the exhaust water inlet pipe, 1# pneumatic valve 12 and 2# pneumatic valve 13 are set on the air inlet pipe 2, and the top of Tower A and Tower B is connected with air outlet pipe 3, 1# one-way valve 16, 2# one-way valve 17, 3# one-way valve 18, 4# one-way valve 19, manual valve 20 and heating cylinder 6 are set on the air outlet pipe 3.

[0003] The working principle of the ash removal air compressor dryer is as follows: if tower A is adsorbing and tower B is regenerating, PLC controls the corresponding solenoid valves to open pneumatic valves 1#12 and 4#15, and close pneumatic valves 2#13 and 3#14. The compressed air to be dried enters from the air inlet, flows through the 1#1 pneumatic valve 12 to the lower part of tower A, and flows through the desiccant from bottom to top in tower A. The moisture in the compressed air to be dried is adsorbed. After the dried compressed air passes through the 1# check valve 16, 94% of the gas is discharged from the air outlet, and about 6% of the dry compressed air enters the heating cylinder 6 through the manual valve 20 and flows through the B tower after heating, taking away the moisture of the desiccant in tower B, and finally discharged from the exhaust water outlet through the 4#1 pneumatic valve 15. This working state lasts for 1 hour, and then switches to the working state of "B tower adsorbs A tower regenerates" (the four pneumatic valves become opposite states, and the working process can be known in the same way), and so on. However, the energy efficiency ratio of the heater of the heating tube 6 is always 1 (the energy efficiency ratio is equal to the ratio of heating power to input power), and 1 kWh of electricity can only generate 1 kWh of heat. The energy consumption required to heat 6% dry compressed air is relatively high. Summary of the invention

[0004] The purpose of the present invention is to address the defects of the prior art and provide a high-efficiency cold-dry adsorption dryer and drying method without a heater. The refrigerant in the heat exchanger is compressed by a compressor, so that the heat exchanger in the heating cylinder dissipates heat and the heat exchanger in the cooling cylinder absorbs heat. The energy efficiency ratio of the compressor heating is about 1:3. Compared with the use of a heater, a large amount of heating energy consumption can be saved.

[0005] In order to solve the above technical problems, the present invention provides a heater-free high-efficiency cold-dry adsorption dryer, comprising a heat exchange system and two drying towers, the two drying towers are connected in parallel through a connecting pipe, the two drying towers are both provided with an air inlet and an air outlet, the connecting pipe comprises an air inlet pipe and an air outlet pipe, the air inlet pipe is connected to the air inlets of the two drying towers, the air outlet pipe is connected to the air outlets of the two drying towers, the air outlet pipe is provided with an air outlet, the heat exchange system comprises a heating cylinder and a cooling cylinder, the heating cylinder is arranged on the air outlet pipe, so that part of the compressed air dried by one of the drying towers is discharged The compressed air enters another drying tower through the heating cylinder, and the other compressed air is discharged from the air outlet of the air outlet pipe. The cooling cylinder is connected to the air inlet pipe. The cooling cylinder is provided with an air inlet. The compressed air to be dried enters the drying tower through the air inlet of the cooling cylinder. Heat exchangers are arranged in the heating cylinder and the cooling cylinder. The two heat exchangers are connected in series through a heat exchange pipe. A compressor and an expansion joint are arranged on the heat exchange pipe. The compressor is used to compress the refrigerant in the heat exchange pipe from low-temperature and low-pressure gas into high-temperature and high-pressure gas. The expansion joint is used to convert normal-temperature and high-pressure liquid into low-temperature and low-pressure liquid, so that the heat exchanger in the heating cylinder dissipates heat and the heat exchanger in the cooling cylinder absorbs heat.

[0006] Furthermore, a gas-liquid separator is provided at the bottom of the cooling cylinder.

[0007] In some embodiments, an air pre-cooler is included, wherein the air pre-cooler is used to perform heat exchange between the compressed air to be dried and the dried compressed air.

[0008] Furthermore, the air precooler is provided with a first channel and a second channel, the first channel is connected to the air inlet of the cooling cylinder, the compressed air to be dried enters the drying tower through the first channel, and the second channel is connected to the air outlet of the air outlet pipe, so that the dried compressed air entering the second channel can exchange heat with the compressed air to be dried in the first channel.

[0009] Furthermore, the air precooler includes a first box body and a second box body, the first channel is arranged in the first box body, a precooling pipe is arranged through the first box body, one end of the precooling pipe is connected to the interior of the second box body, and the precooling pipe and the interior of the second box body form the second channel.

[0010] Furthermore, the air precooler includes a third box body, a second partition is arranged in the second box body, the second partition divides the second box body into a first inner cavity and a second inner cavity, one end of some of the precooling tubes is connected to the first inner cavity, and the other end is connected to the interior of the third box body, one end of the other precooling tubes is connected to the interior of the third box body, and the other end is connected to the second inner cavity, and the precooling tubes, the second box body, and the third box body form the second channel.

[0011] Furthermore, a plurality of first baffles are arranged in the first box body, and the plurality of first baffles enable the compressed air to be dried to flow in a serpentine shape in the first channel.

[0012] Furthermore, the second box body is connected to an outlet main pipe, a return air branch pipe is arranged on the outlet main pipe, the return air branch pipe is connected to the heating cylinder, a manual valve is arranged on the return air branch pipe, and the manual valve is used to control the amount of dried compressed air entering the heating cylinder.

[0013] In some embodiments, fins are provided on the heat exchanger.

[0014] In a second aspect, the present invention provides a drying method of a heater-free high-efficiency cold-drying adsorption dryer, comprising:

[0015] Turn on the compressor to allow the heat exchanger in the heating cylinder to dissipate heat and the heat exchanger in the cooling cylinder to absorb heat. Open the corresponding valves on the air inlet pipe and the exhaust water outlet pipe according to the working status of the two drying towers, so that one drying tower can adsorb and the other drying tower can regenerate.

[0016] The beneficial effects of the present invention are:

[0017] 1. The present invention utilizes a compressor to compress the refrigerant in the heat exchanger, so that the heat exchanger in the heating cylinder dissipates heat and the heat exchanger in the cooling cylinder absorbs heat. The energy efficiency ratio of the compressor heating is about 1:3. Compared with the use of a heater, a large amount of heating energy consumption can be saved. The dried compressed air can be heated when passing through the heating cylinder to regenerate the desiccant. The compressed air to be dried can be cooled when passing through the cooling cylinder, thereby increasing the relative humidity of the compressed air to be dried, making it easier for moisture in the compressed air to be dried to precipitate, which is beneficial to improving the water absorption efficiency of the desiccant.

[0018] 2. The present invention provides an air precooler to perform heat exchange between the dried compressed air and the compressed air to be dried, thereby increasing the temperature of the dried compressed air, avoiding or reducing condensation of the dried compressed air on the pipeline during transportation, and reducing the temperature of the compressed air to be dried, further increasing the relative humidity of the compressed air to be dried.

[0019] 3. The air precooler of the present invention ensures sufficient heat exchange between the dried compressed air and the compressed air to be dried by providing the first box, the second box, and the third box, thereby increasing the temperature of the dried compressed air as much as possible.

[0020] 4. The present invention does not require any changes to the structure of the existing dust removal air compressor dryer. It only requires replacing the heater in the heating cylinder with a heat exchanger and adding a cooling cylinder and an air precooler. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of a ash removal air compressor dryer in the prior art;

[0022] Figure 2 This is a schematic diagram of the structure of the present invention without an air precooler;

[0023] Figure 3 This is a schematic diagram of the structure of the present invention after an air precooler is provided;

[0024] Figure 4 is a flow diagram of the compressed air to be dried in the air precooler of the present invention;

[0025] Figure 5 The figure is a flow diagram of the dried compressed air in the air precooler of the present invention.

[0026] Figure numerals: drying tower 1; air inlet pipe 2; air outlet pipe 3; air outlet water pipe 4; gas-liquid separator 5; heating cylinder 6; cooling cylinder 7; heat exchanger 8; heat exchange pipe 9; compressor 10; expansion joint 11; 1# pneumatic valve 12; 2# pneumatic valve 13; 3# pneumatic valve 14; 4# pneumatic valve 15; 1# check valve 16, 2# check valve 17, 3# check valve 18, 4# check valve 19, manual valve 20; air precooler 21; first box 22; first partition 221; second box 23; second partition 231; first inner cavity 232; second inner cavity 233; third box 24; precooling pipe 25; outlet main pipe 26; return air branch pipe 27. DETAILED DESCRIPTION

[0027] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0028] like Figure 2As shown, the present invention provides a heater-free high-efficiency cold-dry adsorption dryer, comprising a heat exchange system and two drying towers 1, the two drying towers 1 are connected in parallel through a connecting pipe, the two drying towers 1 are respectively Tower A and Tower B, both drying towers 1 are provided with an air inlet and an air outlet, the connecting pipe comprises an air inlet pipe 2, an air outlet pipe 3, and an air outlet water outlet pipe 4, the air inlet pipe 2 and the air outlet water outlet pipe 4 are connected in parallel, the air inlet pipe 2 is connected to the air inlets of the two drying towers 1, a 1# pneumatic valve 12 and a 2# pneumatic valve 13 are arranged on the air inlet pipe 2, the compressed air to be dried can flow through the 1# pneumatic valve 12 or the 2# pneumatic valve 13 on the air inlet pipe 2 into Tower A or Tower B, the air outlet water outlet pipe 4 is also connected to the air inlet of the two drying towers 1, and a 3# pneumatic valve 14 and a 4# pneumatic valve 15 are arranged on the air outlet water outlet pipe 4. The dried compressed air can flow through the 3# pneumatic valve 14 or the 4# pneumatic valve 15 on the air outlet water outlet pipe 4 to be discharged after taking away the moisture of the desiccant. The air outlet pipe 3 is connected to the air outlet of the two drying towers 1. A 1# check valve 16, a 2# check valve 17, a 3# check valve 18, a 4# check valve 19 and a manual valve 20 are arranged on the air outlet pipe 3. Part of the gas in the dried compressed air can flow through the 1# check valve 16 or the 2# check valve 17 and enter one of the drying towers 1 through the manual valve 20, and then be discharged through the 3# pneumatic valve 14 or the 4# pneumatic valve 15 (i.e. Figure 2 The rest of the dry compressed air flows through the 1# check valve 16 or the 2# check valve 17 and is then discharged directly (i.e. Figure 2 ) as indicated by the uppermost arrow in the figure;

[0029] The heat exchange system includes a heating cylinder 6 and a cooling cylinder 7. The heating cylinder 6 is arranged on the air outlet pipe 3, so that part of the compressed air dried by one drying tower 1 enters the other drying tower 1 through the heating cylinder 6, and the other compressed air is discharged from the air outlet of the air outlet pipe 3. The cooling cylinder 7 is connected to the air inlet pipe 2, and an air inlet is provided on the cooling cylinder 7. The compressed air to be dried enters the drying tower 1 (i.e. Figure 2 As shown by the inclined arrow at the bottom, heat exchangers 8 are arranged in the heating tube 6 and the cooling tube 7. The two heat exchangers 8 are connected in series through a heat exchange pipe 9. A compressor 10 and an expansion joint 11 are arranged on the heat exchange pipe 9. The compressor 10 is used to compress the refrigerant in the heat exchange pipe 9 from a low-temperature and low-pressure gas into a high-temperature and high-pressure gas. The expansion joint 11 is used to convert a normal-temperature and high-pressure liquid into a low-temperature and low-pressure liquid, so that the heat exchanger 8 in the heating tube 6 dissipates heat and the heat exchanger 8 in the cooling tube 7 absorbs heat.

[0030] It can be understood that after the refrigerant is compressed into a high-temperature and high-pressure gas by the compressor 10, it enters the heat exchanger 8 of the heating cylinder 6. The heat exchanger 8 of the heating cylinder 6 dissipates heat, so that the compressed air entering the heating cylinder 6 is heated. After the heated compressed air enters the drying tower 1, the regeneration of the desiccant in the drying tower 1 can be realized. The high-temperature and high-pressure refrigerant passes through the heat exchanger 8 of the heating cylinder 6 and becomes a liquid refrigerant at room temperature and high pressure. The liquid refrigerant passes through the expansion joint 11. The small hole structure is arranged inside the expansion joint 11, so that the liquid refrigerant at room temperature and high pressure produces a throttling effect when passing through the small hole, thereby reducing the pressure and forming a low-temperature and low-pressure liquid refrigerant. The low-temperature and low-pressure liquid refrigerant enters the heat exchanger 8 of the cooling cylinder 7. The heat exchanger 8 of the cooling cylinder 7 absorbs heat, which can reduce the temperature of the compressed air to be dried. The lower the temperature of the air, the higher the humidity, which is conducive to improving the adsorption effect of the desiccant. Thus, the cycle of adsorption and regeneration of the two drying towers 1 is realized.

[0031] Since the present application directly utilizes the heat exchange system to realize the circulation and regeneration of the two drying towers 1, there is no need to use the heater in the heating tube 6 to heat the compressed air after drying, and the energy efficiency ratio of the heat exchange system is about 1:3, that is, 1 kWh of electricity can generate more than 3 kWh of heat. Compared with using the heater in the heating tube 6, a lot of heating energy consumption can be saved.

[0032] Furthermore, a gas-liquid separator 5 is provided at the bottom of the cooling cylinder 7 .

[0033] Since the temperature of the compressed air to be dried is lowered before being dried, condensation is easily generated on the pipeline during the transportation of the dried compressed air. In order to avoid or reduce condensation, Figure 3 As shown, in some embodiments, the heater-free high-efficiency cold-dry adsorption dryer includes an air precooler 21, which is used to perform heat exchange between the compressed air to be dried and the dried compressed air.

[0034] It can be understood that the compressed air to be dried that has not yet entered the device is higher than the compressed air after compression. Therefore, the two can be heat exchanged to pre-cool the compressed air to be dried and heat up the compressed air after compression, which not only improves the drying effect of the compressed air to be dried, but also solves the problem that condensation is easy to occur in the dried compressed air.

[0035] Furthermore, the air precooler 21 is provided with a first channel and a second channel, the first channel is connected to the air inlet of the cooling cylinder 7, the compressed air to be dried enters the drying tower 1 through the first channel, and the second channel is connected to the air outlet of the air outlet pipe 3, so that the dried compressed air entering the second channel can exchange heat with the compressed air to be dried in the first channel.

[0036] Furthermore, if Figure 4, 5 As shown, the air precooler 21 includes a first box body 22 and a second box body 23, a first channel is arranged in the first box body 22, a precooling pipe 25 is arranged through the first box body 22, one end of the precooling pipe 25 is communicated with the interior of the second box body 23, and the precooling pipe 25 and the interior of the second box body 23 form a second channel. The first box body 22 and the second box body 23 can be connected by welding or share a side.

[0037] Furthermore, if Figure 5 As shown, the air precooler 21 includes a third box body 24, the second box body 23 and the third box body 24 are respectively arranged on both sides of the first box body 22, a second partition 231 is arranged in the second box body 23, and the second partition 231 divides the second box body 23 into a first inner cavity 232 and a second inner cavity 233, one end of some precooling pipes 25 is connected to the first inner cavity 232, and the other end is connected to the interior of the third box body 24, one end of other precooling pipes 25 is connected to the interior of the third box body 24, and the other end is connected to the second inner cavity 233, and the precooling pipes 25, the second box body 23, and the third box body 24 form a second channel, Figure 5 The arrows in the diagram indicate the flow direction of the dried compressed air.

[0038] Furthermore, if Figure 4 As shown, a plurality of first baffles 221 are arranged in the first box body 22, and the plurality of first baffles 221 allow the compressed air to be dried to flow in a serpentine shape in the first channel. Figure 4 The arrows in the figure indicate the flow direction of the compressed air to be dried.

[0039] By providing the first box body 22, the second box body 23, and the third box body 24, it is ensured that the dried compressed air and the compressed air to be dried can fully exchange heat, and the temperature of the dried compressed air can be increased as much as possible.

[0040] Furthermore, if Figure 3 As shown, the second box body 23 is connected to an outlet main pipe 26, a return air branch pipe 27 is arranged on the outlet main pipe 26, the return air branch pipe 27 is connected to the heating cylinder 6, a manual valve 20 is arranged on the return air branch pipe 27, and the manual valve 20 is used to control the amount of dried compressed air entering the heating cylinder 6.

[0041] The dried compressed air that has passed through the air precooler 21 is introduced into the heating cylinder 6, so that the temperature of the dried compressed gas entering the drying tower 1 is higher, which is beneficial to the regeneration of the desiccant.

[0042] In some embodiments, fins are provided on the heat exchanger 8 .

[0043] The present invention also provides a drying method of a heater-free high-efficiency cold-drying adsorption dryer, comprising:

[0044] The compressor 10 is turned on to make the heat exchanger 8 in the heating cylinder 6 dissipate heat and the heat exchanger 8 in the cooling cylinder 7 absorb heat. The corresponding valves on the air inlet pipe 2 and the exhaust water outlet pipe are opened according to the working status of the two drying towers 1, so that one drying tower 1 adsorbs and the other drying tower 1 regenerates.

[0045] Specifically, take the working adsorption of tower A and the regeneration drainage of tower B as examples: PLC controls the corresponding solenoid valves, so that the pneumatic valves 1# pneumatic valve 12 and 4# pneumatic valve 15 are opened, and the 2# pneumatic valves 13 and 3# pneumatic valves 14 are closed, and the compressed air to be dried enters tower A through the air precooler 21, the cooling cylinder 7, and the 1# pneumatic valve 12 of the air inlet pipe 2 in sequence. When the compressed air to be dried passes through the cooling cylinder 7, the temperature decreases and the humidity increases. When the compressed air to be dried passes through the desiccant in tower A, the drying effect is better;

[0046] Then the dried compressed air enters the air precooler 21 through the 1# one-way valve 16. In the air precooler 21, the dried compressed air exchanges heat with the compressed air to be dried, thereby increasing the temperature of the dried compressed air and reducing the temperature of the compressed air to be dried (i.e., the compressed air to be dried is precooled). 94% of the gas in the dried compressed air is discharged through the outlet main pipe 26, and 6% of the gas enters the heating cylinder 6 through the return air branch pipe 27 and the manual valve 20. The heat exchanger 8 in the heating cylinder 6 dissipates heat. After being heated in the heating cylinder 6, the dried compressed air enters the B tower through the 4# one-way valve 19. The high-temperature dried compressed air takes away the moisture of the desiccant in the B tower and is discharged through the 4# pneumatic valve 15.

[0047] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A high-efficiency cold-drying adsorption dryer without heater, characterized in that: The invention comprises a heat exchange system and two drying towers (1), wherein the two drying towers (1) are connected in parallel via a connecting pipe, and the two drying towers (1) are both provided with an air inlet and an air outlet, wherein the connecting pipe comprises an air inlet pipe (2) and an air outlet pipe (3), wherein the air inlet pipe (2) is connected to the air inlets of the two drying towers (1), and the air outlet pipe (3) is connected to the air outlets of the two drying towers (1), and the air outlet pipe (3) is provided with an air outlet, and the heat exchange system comprises a heating cylinder (6) and a cooling cylinder (7), wherein the heating cylinder (6) is arranged on the air outlet pipe (3), so that part of the compressed air dried by one of the drying towers (1) enters the other drying tower (1) through the heating cylinder (6), and the rest of the compressed air is discharged from the air outlet pipe (3). The air is discharged from the outlet of the outlet pipe (3), the cooling cylinder (7) is connected to the air inlet pipe (2), the cooling cylinder (7) is provided with an air inlet, and the compressed air to be dried enters the drying tower (1) through the air inlet of the cooling cylinder (7), the heating cylinder (6) and the cooling cylinder (7) are both provided with a heat exchanger (8), the two heat exchangers (8) are connected in series through a heat exchange pipe (9), a compressor (10) and an expansion joint (11) are provided on the heat exchange pipe (9), the compressor (10) is used to compress the refrigerant in the heat exchange pipe (9) from low-temperature and low-pressure gas into high-temperature and high-pressure gas, and the expansion joint (11) is used to convert normal-temperature and high-pressure liquid into low-temperature and low-pressure liquid, so that the heat exchanger (8) in the heating cylinder (6) dissipates heat and the heat exchanger (8) in the cooling cylinder (7) absorbs heat.

2. The heater-free high-efficiency cold-drying adsorption dryer according to claim 1 is characterized in that: A gas-liquid separator (5) is arranged at the bottom of the cooling cylinder (7).

3. The heater-free high-efficiency cold-drying adsorption dryer according to claim 1 or 2, characterized in that: It comprises an air precooler (21), wherein the air precooler (21) is used to perform heat exchange between compressed air to be dried and compressed air that has been dried.

4. The heater-free high-efficiency cold-drying adsorption dryer according to claim 3 is characterized in that: The air precooler (21) is provided with a first channel and a second channel, wherein the first channel is connected to the air inlet of the cooling cylinder (7), and the compressed air to be dried enters the drying tower (1) through the first channel, and the second channel is connected to the air outlet of the air outlet pipe (3), so that the dried compressed air entering the second channel is heat-exchanged with the compressed air to be dried in the first channel.

5. The heater-free high-efficiency cold-drying adsorption dryer according to claim 4 is characterized in that: The air precooler (21) comprises a first box (22) and a second box (23), the first channel is arranged in the first box (22), a precooling pipe (25) is arranged through the first box (22), one end of the precooling pipe (25) is connected to the interior of the second box (23), and the precooling pipe (25) and the interior of the second box (23) form the second channel.

6. The heater-free high-efficiency cold-drying adsorption dryer according to claim 5 is characterized in that: The air precooler (21) comprises a third box (24); a second partition (231) is arranged in the second box (23); the second partition (231) divides the second box (23) into a first inner cavity (232) and a second inner cavity (233); one end of some of the precooling tubes (25) is connected to the first inner cavity (232) and the other end is connected to the interior of the third box (24); one end of other precooling tubes (25) is connected to the interior of the third box (24) and the other end is connected to the second inner cavity (233); the precooling tubes (25), the second box (23) and the third box (24) form the second channel.

7. The heater-free high-efficiency cold-drying adsorption dryer according to claim 5 is characterized in that: A plurality of first baffles (221) are arranged in the first box body (22), and the plurality of first baffles (221) enable the compressed air to be dried to flow in a serpentine shape in the first channel.

8. The heater-free high-efficiency cold-drying adsorption dryer according to claim 6 is characterized in that: The second box body (23) is connected to an outlet main pipe (26), a return air branch pipe (27) is arranged on the outlet main pipe (26), the return air branch pipe (27) is connected to the heating cylinder (6), a manual valve (20) is arranged on the return air branch pipe (27), and the manual valve (20) is used to control the amount of dried compressed air entering the heating cylinder (6).

9. The heater-free high-efficiency cold-drying adsorption dryer according to any one of claims 4 to 8, characterized in that: The heat exchanger (8) is provided with fins.

10. A drying method of a high-efficiency cold-drying adsorption dryer without a heater according to any one of claims 1 to 9, characterized in that: include: The compressor (10) is turned on, so that the heat exchanger (8) in the heating cylinder (6) dissipates heat and the heat exchanger (8) in the cooling cylinder (7) absorbs heat. The corresponding valves on the air inlet pipe (2) and the exhaust water outlet pipe are opened according to the working status of the two drying towers (1), so that one drying tower (1) adsorbs and the other drying tower (1) regenerates.

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