Energy-saving compressed air drying and purifying device and control method

Abstract

This invention discloses an energy-saving compressed air drying and purification device and control method, belonging to the field of compressed air treatment technology. The device includes an inlet pipeline, an outlet pipeline, a gas-liquid separation unit, a dual adsorption drying unit, a regeneration heating unit, a purified output unit, a detection unit, and an intelligent control unit. The dual adsorption drying unit employs two tanks operating alternately. The regeneration heating unit is equipped with separate heating control valves and cold blowing control valves, and is configured with a small-diameter regeneration gas consumption proportional adjustment valve to achieve precise control of regeneration gas consumption. The control method includes adsorption drying, dew point detection switching, backup tank regeneration, and seasonal adaptive control for spring / summer / autumn / winter seasons, adjusting the switching cycle and heating and cold blowing times in real time based on the dew point. This invention reduces regeneration gas consumption to 2%–3%, and the output air dew point meets ultra-dry requirements. It combines advantages such as good purification effect, low energy consumption, stable operation, and intelligent adaptive control, making it suitable for deep drying and purification scenarios of industrial compressed air.

Description

Technical Field

[0001] This invention relates to the field of compressed air treatment technology, and more specifically, to an energy-saving compressed air drying and purification device and control method. Background Technology

[0002] Compressed air, as a clean, safe, and efficient power source, is widely used in various industrial fields such as machinery manufacturing, chemical industry, electronics, pharmaceuticals, and food processing. However, the atmosphere naturally contains impurities such as moisture, particulate matter, and oil. After being compressed by an air compressor, these impurities will exist in the compressed air at a higher concentration. Especially during the humid spring and summer seasons, when the air humidity is high and the moisture content is high, the moisture content in the compressed air will increase significantly.

[0003] These impurities can cause serious damage to pneumatic systems: moisture can cause corrosion of control valves and actuators, reducing equipment lifespan; particulate matter and oil can clog valve cores and pipelines, resulting in reduced control accuracy or even control failure; in industries with extremely high air quality requirements, such as precision electronics and pharmaceuticals, substandard compressed air can directly affect product quality, causing huge economic losses. Therefore, compressed air must undergo strict drying and purification treatment to meet the corresponding usage standards.

[0004] However, existing compressed air drying and purification methods have the following drawbacks: 1. High regeneration air consumption and high energy consumption: Conventional micro-heat regeneration dryers typically consume 5-8% of the rated processing flow rate during regeneration. A large amount of the dried compressed air is directly discharged, resulting in serious energy waste.

[0005] 2. Inaccurate flow control: The heating regeneration and cold blowing cooling share the same pipeline and valves, making it impossible to optimize the gas flow rate for the heating and cold blowing stages separately. To ensure the cold blowing effect, valves with larger diameters must be used, resulting in excessive gas consumption during the heating stage. Summary of the Invention

[0006] The energy-saving compressed air drying and purification device provided by this invention aims to solve the following problems: existing micro-heat regeneration adsorption dryers cannot achieve both high drying level and low energy consumption, and suffer from problems such as large regeneration air consumption, inaccurate control of heating and cold blowing flow, insufficient purification effect, and lack of intelligent adaptive capability.

[0007] To achieve the above objectives, the present invention provides the following technical solution: Energy-saving compressed air drying and purification equipment, including The intake pipe is used to input the wet compressed air to be processed. The air outlet pipeline is used to transport compressed air that has undergone drying and purification treatment; The gas-liquid separation unit, connected in series with the intake pipe, is used to separate liquid water and coarse particulate matter carried by the compressed air in the intake pipe, and to automatically discharge the separated liquid water and particulate matter periodically. The dual adsorption drying unit is set in parallel between the gas-liquid separation unit and the outlet pipeline to alternately perform adsorption drying of compressed air and regeneration of adsorbent, so as to realize continuous drying treatment of compressed air. The regeneration heating unit is connected between the gas outlet pipeline and the dual adsorption drying unit. It is used to provide the gas passage and heat source required for heating and regeneration and cold blowing cooling of the adsorption drying tank in the regeneration state in the dual adsorption drying unit, so as to realize the desorption and regeneration of the adsorbent. The purification output unit is connected in series with the air outlet pipeline. It is used to filter out trace dust particles carried in the dried compressed air and automatically discharge the filtered particles periodically. The detection units are installed on the inlet pipe, outlet pipe, dual adsorption drying unit and regeneration heating unit respectively, and are used to detect the pressure, temperature and compressed air dew point parameters in real time during the operation of the device. The intelligent control unit is electrically connected to the gas-liquid separation unit, the dual adsorption drying unit, the regeneration heating unit, the purification output unit, and the detection unit, respectively. It is used to receive feedback signals from the detection unit, automatically control the operating status of each component, and realize intelligent energy-saving control of the device.

[0008] Furthermore, the gas-liquid separation unit includes a gas-liquid separator connected in series on the air intake pipe. The gas-liquid separator is a cyclone filter type gas-liquid separator, and an automatic drain valve is connected to the bottom of the gas-liquid separator.

[0009] Furthermore, the dual adsorption drying unit includes a first adsorption drying tank and a second adsorption drying tank arranged in parallel. The air inlets of the first adsorption drying tank and the second adsorption drying tank are respectively connected to the air outlet of the gas-liquid separation unit through a first air inlet control valve and a second air inlet control valve. The air outlets are respectively connected to the air outlet pipeline through a first drying output pipeline check valve and a second drying output pipeline check valve. The regeneration exhaust port is respectively connected to the muffler through a first regeneration gas consumption proportional adjustment valve, a second regeneration gas consumption proportional adjustment valve, a first quick release valve, and a second quick release valve. The diameters of the first regeneration gas consumption proportional adjustment valve and the second regeneration gas consumption proportional adjustment valve are both smaller than the diameters of the first air inlet control valve and the second air inlet control valve.

[0010] Furthermore, the regeneration heating unit includes a pipeline heater, a heating control valve, a cold blowing control valve, a first regeneration pipeline check valve, and a second regeneration pipeline check valve. The inlet end of the heating control valve is connected to the outlet pipeline, and the outlet end is connected to the inlet end of the pipeline heater. The inlet end of the cold blowing control valve is connected to the outlet pipeline. After the outlet ends of the pipeline heater and the cold blowing control valve merge, they are connected to the dual adsorption drying unit through the first regeneration pipeline check valve and the second regeneration pipeline check valve, respectively. The diameter of the heating control valve is smaller than the diameter of the cold blowing control valve.

[0011] Furthermore, the purification output unit includes a self-cleaning filter connected in series in the outlet pipeline, with an automatic discharge valve connected to the bottom of the self-cleaning filter; the detection unit includes a pressure sensor for detecting the pressure in the inlet and outlet pipelines, a temperature sensor for detecting the dual adsorption drying unit and the regeneration heating unit, and a dew point sensor for detecting the dew point of the compressed air in the outlet pipeline.

[0012] Furthermore, the intelligent control unit includes an operation control cabinet, which contains a PLC controller and an HMI operation interface. The PLC controller is used to control the operating status of each unit, and the HMI operation interface is configured to display the device flowchart, valve status, outlet temperature, heater operating status, internal temperature of the two adsorption drying tanks, outlet dew point parameters, and equipment operation, alarm and shutdown status.

[0013] Furthermore, the first and second adsorption drying tanks are filled with a regenerable desiccant, which is activated alumina or a mixture of molecular sieve and activated alumina.

[0014] A control method for an energy-saving compressed air drying and purification device includes the following steps: S1. Adsorption and Drying Stage: The PLC controller controls one of the adsorption and drying tanks as the working tank and the other as the backup tank. After the wet compressed air enters the gas-liquid separator through the air inlet pipeline to separate liquid water and coarse particles, it enters the working tank through the corresponding air inlet control valve. After the desiccant in the tank adsorbs the moisture, the dried compressed air enters the outlet pipeline through the corresponding drying output pipeline check valve, and is then filtered by the self-cleaning filter before being output. S2, Dew Point Detection and Switching Stage: The dew point sensor detects the dew point value of the compressed air in the outlet pipeline in real time. When the detected dew point value drops to the preset switching threshold, the PLC controller automatically completes the switching between the working tank and the standby tank. The original working tank becomes the standby tank, and the original standby tank becomes the new working tank. S3, Standby Tank Regeneration Stage: After switching, the standby tank undergoes four processes in sequence: rapid unloading, heating, cold blowing, and pressurization to complete the regeneration of the adsorbent; S4. Seasonal Adaptive Control Stage: The PLC controller automatically selects the spring / summer control mode or the autumn / winter control mode based on the ambient air humidity, and adaptively adjusts the working / standby tank switching cycle, heating time, and cold blowing time parameters in different modes.

[0015] Furthermore, in step S2, the preset switching threshold is -20℃; when the dew point value detected by the dew point sensor (16) is ≤-40℃, the device maintains the current working state; In step S3, during the heating process, the PLC controller controls the opening degree of the corresponding regeneration gas consumption proportional adjustment valve to 25%, and during the cold blowing process, it controls the opening degree of the corresponding regeneration gas consumption proportional adjustment valve to 50%.

[0016] Furthermore, in step S3 The quick unloading process is as follows: The PLC controller controls the quick unloading valve corresponding to the spare tank to open, so that the pressure inside the tank drops from the working pressure to atmospheric pressure within a few seconds; The heating process is as follows: The PLC controller turns on the pipeline heater, opens the heating control valve, closes the cold blowing control valve, and controls the opening of the corresponding regeneration gas consumption ratio regulating valve to 25%, so that 2%-3% of the rated flow of dry compressed air in the outlet pipeline enters the standby tank after heating, and exchanges heat with the adsorbent to remove moisture. The heating time is 1-2 hours. The cold blowing process is as follows: The PLC controller shuts off the pipeline heater and heating control valve, opens the cold blowing control valve, and controls the opening degree of the corresponding regeneration gas consumption ratio regulating valve to 50%, so that 3%-5% of the rated flow of dry compressed air in the outlet pipeline enters the spare tank to cool the adsorbent and further desorb moisture. The cold blowing time is 15-20 minutes. The pressurization process is as follows: the PLC controller closes the corresponding regeneration gas consumption ratio regulating valve, keeps the cold blowing control valve open, and allows the compressed air in the outlet pipeline to enter the standby tank until the pressure in the tank is balanced with the pressure in the working tank, and the standby tank enters the standby switching state.

[0017] The beneficial effects of this invention are as follows: This invention reduces regeneration gas consumption from the conventional 5-8% to 2-3% by using a small-diameter regeneration gas consumption proportional regulating valve and separating the heating control valve and the cold blowing control valve, thereby optimizing the flow parameters of the two stages. At the same time, it also reduces the power consumption of the electric heater, resulting in significant energy saving.

[0018] This invention employs a dual control mode combining dew point control and time control, and sets two seasonal operation modes: spring / summer and autumn / winter. The PLC controller automatically adjusts the working / standby tank switching cycle, heating time, and cold blowing time based on real-time detected output dew point values ​​and ambient humidity data. This ensures both the drying effect of the output compressed air and avoids energy waste caused by excessive regeneration.

[0019] This invention employs a dual-adsorption drying tank alternating operation method to achieve continuous drying of compressed air; all control valves are double-eccentric metal hard-seal stainless steel butterfly valves, which have a long service life and good sealing performance; equipped with a complete pressure, temperature, dew point detection and alarm system, it can promptly detect and handle equipment failures.

[0020] This invention is equipped with an HMI (Human Machine Interface) that intuitively displays the device flowchart, valve status, operating parameters, and alarm information, making operation simple and convenient. The self-cleaning filter can automatically filter and discharge dust particles, reducing the amount of manual maintenance required. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings: Figure 1 This is a flowchart of the energy-saving compressed air drying and purification device of the present invention.

[0022] In the diagram: 1. Gas-liquid separator; 2. Automatic drain valve; 3-1. First adsorption drying tank; 3-2. Second adsorption drying tank; 4-1. First air inlet control valve; 4-2. Second air inlet control valve; 5-1. First regeneration gas consumption proportional regulating valve; 5-2. Second regeneration gas consumption proportional regulating valve; 6-1. First quick release valve; 6-2. Second quick release valve; 7. Silencer; 8. Operation control cabinet; 9. Pipeline heater; 10. Temperature sensor; 11. Heating control valve; 12. Cold blowing control valve; 13-1. First regeneration pipeline check valve; 13-2. Second regeneration pipeline check valve; 14-1. First dried output pipeline check valve; 14-2. Second dried output pipeline check valve; 15. Pressure sensor; 16. Dew point sensor; 17. Self-cleaning filter; 18. Automatic discharge valve. Detailed Implementation

[0023] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0024] like Figure 1 As shown, this is the energy-saving compressed air drying and purification device of the present invention. The overall structure adopts a micro-heat regenerative adsorption drying method with alternating operation of dual adsorption drying tanks. Specifically, it includes an inlet pipe, an outlet pipe, a gas-liquid separation unit, a dual adsorption drying unit, a regenerative heating unit, a purification output unit, a detection unit, and an intelligent control unit. The inlet pipe is used to input the humid compressed air to be treated, and the outlet pipe is used to deliver the dried and purified compressed air.

[0025] The gas-liquid separation unit is connected in series between the air inlet pipe and the dual adsorption drying unit, and includes a cyclone filter-type gas-liquid separator 1 and an automatic drain valve 2. The gas-liquid separator 1 uses the principle of centrifugal force to separate liquid water droplets and coarse particles carried in compressed air. The automatic drain valve 2 is installed at the bottom of the gas-liquid separator 1 and adopts an electric opening / closing control method to periodically discharge the precipitated liquid water and particulate matter.

[0026] A dual adsorption drying unit is connected in parallel between the gas-liquid separation unit and the outlet pipeline. It includes a first adsorption drying tank 3-1 and a second adsorption drying tank 3-2 connected in parallel. Both the first adsorption drying tank 3-1 and the second adsorption drying tank 3-2 have identical structures, being cylindrical canisters containing regenerable desiccant. Their function is to adsorb water vapor from compressed air and output dried compressed air. The air inlets of the first adsorption drying tank 3-1 and the second adsorption drying tank 3-2 are respectively connected to the gas-liquid separation unit via a first air inlet control valve 4-1 and a second air inlet control valve 4-2. The outlet of the unit is connected to the outlet pipeline through the first drying output pipeline check valve 14-1 and the second drying output pipeline check valve 14-2. The regeneration exhaust port is connected to the muffler 7 through the first regeneration gas consumption ratio regulating valve 5-1, the second regeneration gas consumption ratio regulating valve 5-2, the first quick release valve 6-1, and the second quick release valve 6-2. The diameters of the first regeneration gas consumption ratio regulating valve 5-1 and the second regeneration gas consumption ratio regulating valve 5-2 are both smaller than the diameters of the first intake control valve 4-1 and the second intake control valve 4-2.

[0027] In this invention, the regenerable desiccant can be selected from 100% activated alumina or a mixture of 30% molecular sieve and 70% activated alumina. In this invention, when the first adsorption drying tank 3-1 is in the adsorption drying working state, the second adsorption drying tank 3-2 is in the regeneration working state, that is, the regenerable desiccant is desorbed and regenerated; when the second adsorption drying tank 3-2 is in the adsorption drying working state, the first adsorption drying tank 3-1 is in the regeneration working state.

[0028] In this invention, both the intake control valve and the quick-release valve are pneumatically or electrically driven. The valve core is a double-eccentric metal hard-seal stainless steel butterfly valve. The function of the intake control valve is to control the opening / closing of the intake pipeline of the adsorption drying tank. The quick-release valve is located between the adsorption drying tank and the silencer 7. When the working tank is switched to the standby tank, the quick-release valve under the standby tank opens, and the air pressure in the standby tank drops rapidly from high pressure (working pressure, such as 6 bar) to atmospheric pressure (relative pressure of 0). The silencer 7 is a steel silencer, whose function is to reduce exhaust noise.

[0029] The regeneration gas consumption proportional control valve is a pneumatic or electric proportional flow control valve located between the adsorption-drying tank and the silencer 7. It controls the exhaust gas consumption during heating and cold blowing operations. Its diameter is smaller than that of the inlet control valve (e.g., if the inlet control valve diameter is 100mm, the proportional control valve diameter can be 25mm) to achieve precise control of regeneration gas consumption and reduce compressed air consumption during adsorbent regeneration. During heating, to ensure sufficient heat exchange between the heated compressed air and the adsorbent, the control system provides a smaller proportional valve opening, such as 25%, at which point the gas consumption is approximately 2-3% of the rated processing flow. During cold blowing, to allow the adsorbent to cool more quickly, the control system provides a larger proportional valve opening, such as 50%, at which point the gas consumption is approximately 3-5% of the rated processing flow. When the adsorption-drying tank is in operation, the regeneration gas consumption proportional control valve below the tank is closed, i.e., the opening value is 0.

[0030] The regeneration heating unit is connected between the outlet pipeline and the dual adsorption drying unit. It includes a pipeline heater 9, a heating control valve 11, a cold blowing control valve 12, a first regeneration pipeline check valve 13-1, and a second regeneration pipeline check valve 13-2. The inlet end of the heating control valve 11 is connected to the outlet pipeline, and the outlet end is connected to the inlet end of the pipeline heater 9. The inlet end of the cold blowing control valve 12 is connected to the outlet pipeline. After the outlet ends of the pipeline heater 9 and the cold blowing control valve 12 merge, they are connected to the dual adsorption drying unit through the first regeneration pipeline check valve 13-1 and the second regeneration pipeline check valve 13-2, respectively.

[0031] In this embodiment, the heating control valve 11 and the cold blowing control valve 12 are set separately so that the compressed air required for the cold blowing of the standby tank is slightly larger than that required for heating, so as to ensure that the adsorbent in the standby tank is cooled to room temperature within 10-15 minutes.

[0032] Both the heating control valve 11 and the cold blowing control valve 12 are double-eccentric metal hard-seal stainless steel butterfly valves. The diameter of the heating control valve 11 is smaller than that of the cold blowing control valve 12. For example, if the diameter of the valve on the spare tank inlet pipe is 100mm, then the diameter of the cold blowing control valve 12 is 32mm and the diameter of the heating control valve 11 is 20mm. The pipeline heater 9 adopts a resistance wire heating structure, and the heating element uses a stainless steel pipe protective sleeve and a high-temperature resistance alloy wire.

[0033] The purification output unit is connected in series on the air outlet pipeline and includes a self-cleaning filter 17 and an automatic discharge valve 18. The self-cleaning filter 17 is used to filter out trace dust particles carried in the dried compressed air. The automatic discharge valve 18 is installed at the bottom of the self-cleaning filter 17 and is electrically operated to periodically discharge the filtered particles.

[0034] The detection unit includes two pressure sensors 15, three temperature sensors 10, and one dew point sensor 16. The two pressure sensors 15 are installed on the inlet and outlet pipes, respectively, to monitor the inlet and outlet pressures of the system in real time. When the pressure difference between the inlet and outlet exceeds 0.5 bar, a blockage alarm signal is issued. The three temperature sensors 10 are installed at the outlet of the pipeline heater 9 and inside the two adsorption drying tanks, respectively, to monitor the regeneration gas temperature and adsorbent temperature in real time. The temperature sensors 10 are insertion-type Pt100 platinum resistance temperature sensors. The dew point sensor 16 is installed on the outlet pipe upstream of the self-cleaning filter 17, with a detection range of -80℃ to +20℃, to monitor the dew point value of the output compressed air in real time.

[0035] The intelligent control unit includes an operation control cabinet 8, which houses a PLC controller and an HMI (Hardware-Machine Interface). The PLC controller is electrically connected to all control valves, pipeline heaters 9, and detection units, receiving feedback signals from the detection units and automatically controlling the operating status of each component. All control valves are equipped with valve position detection switches, which send the valve's open / closed position signals to the PLC controller. An alarm signal is issued when the feedback position does not match the command. The HMI interface displays parameters such as the device flow chart, valve status, outlet temperature, heater operating status, internal temperatures of the two adsorption drying tanks, outlet dew point, and the equipment's operating, alarm, and shutdown status.

[0036] This invention also provides a control method for an energy-saving compressed air drying and purification device, comprising the following steps: S1. Adsorption and Drying Stage: The PLC controller controls one of the adsorption and drying tanks as the working tank and the other as the backup tank. The wet compressed air enters the gas-liquid separator 1 through the air inlet pipeline to separate liquid water and coarse particles. Then, it enters the working tank through the corresponding air inlet control valve. Under high pressure, the desiccant in the tank adsorbs the moisture in the compressed air. The dried compressed air enters the outlet pipeline through the corresponding one-way valve of the dried output pipeline. After passing through the self-cleaning filter 17 to remove trace dust, it is then output.

[0037] S2. Dew Point Detection and Switching Stage: Dew point sensor 16 detects the dew point value of the compressed air in the outlet pipeline in real time. When the detected dew point value drops to the preset switching threshold of -20℃, it indicates that the desiccant in the working tank is close to saturation, and the PLC controller automatically switches between the working tank and the standby tank. The original working tank becomes the standby tank, and the original standby tank becomes the new working tank, continuing the adsorption drying operation. When the dew point value detected by dew point sensor 16 is ≤-40℃, it indicates that the desiccant adsorption capacity in the working tank is sufficient, and the device maintains its current operating state.

[0038] S3, Standby Tank Regeneration Stage: After switching, the standby tank undergoes four processes in sequence: rapid unloading, heating, cold blowing, and pressurization to complete the regeneration of the adsorbent; The quick unloading process is as follows: The PLC controller controls the quick unloading valve corresponding to the spare tank to open, so that the pressure inside the tank drops from the working pressure to atmospheric pressure within a few seconds, creating a low partial pressure environment for adsorbent desorption. The heating process is as follows: The PLC controller activates the pipeline heater 9, opens the heating control valve 11, closes the cold blowing control valve 12, and controls the opening degree of the corresponding regeneration gas consumption proportional adjustment valve to 25%. At this time, 2%-3% of the rated flow of dry compressed air in the outlet pipeline enters the pipeline heater 9 through the heating control valve 11, is heated to 170-180℃, and then enters the spare tank through the corresponding regeneration pipeline check valve. The high-temperature dry air fully exchanges heat with the adsorbent, causing the moisture in the adsorbent to be desorbed into water vapor. The water vapor, together with the hot compressed air, is discharged into the air through the regeneration gas consumption proportional adjustment valve and the silencer 7. The heating process lasts for 1-2 hours. Furthermore, during the heating of the spare tank, to ensure that the heated compressed air can enter the spare tank and fully exchange heat with the regenerable adsorbent, the regeneration gas consumption proportional control valve needs to be opened appropriately. This allows a minimal amount of compressed air in the outlet pipeline to vent from the pipeline heater 9 to the spare tank and then to the silencer 7. The purpose of setting the regeneration gas consumption proportional control valve is to minimize the regeneration gas consumption by proportionally adjusting the valve opening. For example, if the spare tank inlet pipeline valve has a diameter of 100mm, the heating control valve 11 has a diameter of 25mm, and the regeneration gas consumption proportional control valve also has a diameter of 25mm, the flow capacity of the fully open regeneration gas consumption proportional control valve is approximately 6% of that of the 100mm inlet pipeline valve. If the opening of the regeneration gas consumption proportional control valve is set to 25% during heating, then according to the flow characteristic curve of the proportional valve, the corresponding flow rate is approximately 1.5% of that of the 100mm inlet pipeline valve, which can be ignored.

[0039] The cold blowing process is as follows: The PLC controller shuts off the pipeline heater 9 and heating control valve 11, opens the cold blowing control valve 12, and controls the opening degree of the corresponding regeneration gas consumption proportional adjustment valve to 50%. At this time, 3%-5% of the rated flow rate of room temperature dry compressed air in the outlet pipeline enters the standby tank through the cold blowing control valve 12 and the corresponding regeneration pipeline check valve. The room temperature dry air fully exchanges heat with the high temperature adsorbent, causing the adsorbent temperature to drop rapidly, while further desorbing residual moisture. The cold blowing process lasts for 15-20 minutes.

[0040] The pressurization process is as follows: The PLC controller closes the corresponding regeneration gas consumption proportional adjustment valve while keeping the cold blowing control valve 12 open. Compressed air from the outlet pipeline enters the standby tank via the cold blowing control valve 12 and the corresponding regeneration pipeline check valve, gradually increasing the pressure inside the tank until it reaches equilibrium with the working tank pressure. After the pressurization process is completed, the standby tank enters the ready-to-switch state.

[0041] Backup tank regeneration: When the adsorbent in the working tank reaches saturation, the working tank automatically switches to the backup tank. A small amount of high-pressure, high-temperature regeneration gas (usually heated dry air) is introduced into the backup tank through a pipeline. The following physical processes occur inside the backup tank: 1. Thermal diffusion: High-temperature gas causes the moisture in the adsorbent to evaporate, forming vapor that diffuses upwards to the top of the tank.

[0042] 2. Low partial pressure: After the regeneration gas is depressurized, it enters the adsorption layer, reducing the partial pressure of water and promoting the rapid desorption of the remaining water.

[0043] 3. Heat exchange: The latent heat released by the adsorbent is absorbed by the regeneration gas, forming a heat cycle and reducing external heating energy consumption.

[0044] 4. Adsorbent circulation: After regeneration, the temperature of the adsorbent decreases and the pressure rises, then it enters a standby waiting state.

[0045] S4. Seasonal Adaptive Control Stage: The PLC controller automatically selects either the spring / summer or autumn / winter control mode based on the ambient air humidity. In spring and summer, when the air is humid and the compressed air has a high moisture content, the control system automatically selects the spring / summer control mode; in autumn and winter, when the air is dry and the compressed air has a low moisture content, the control system automatically selects the autumn / winter control mode. The working / standby tank switching cycle, heating time, and cold blowing time are all longer in the spring / summer control mode than the corresponding parameters in the autumn / winter control mode.

[0046] In addition, the PLC controller can provide time control mode, manual control mode, and remote control mode. In time control mode, the PLC controller automatically completes the cyclic operation of the device according to the preset fixed switching cycle, heating time, and cold blowing time. In manual control mode, the operator can manually control the operation of each valve and heater through the HMI operation interface. In remote control mode, the PLC controller can receive remote control commands to realize remote monitoring and operation of the device.

[0047] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. An energy-saving compressed air drying and purification device, characterized in that: include The intake pipe is used to input the wet compressed air to be processed. The air outlet pipeline is used to transport compressed air that has undergone drying and purification treatment; A gas-liquid separation unit, connected in series with the air intake pipe, is used to separate liquid water and coarse particulate matter carried by compressed air in the air intake pipe, and to automatically discharge the separated liquid water and particulate matter periodically. A dual adsorption drying unit is connected in parallel between the gas-liquid separation unit and the outlet pipeline to alternately perform adsorption drying of compressed air and regeneration of adsorbent, thereby achieving continuous drying treatment of compressed air. The regeneration heating unit is connected between the gas outlet pipeline and the dual adsorption drying unit. It is used to provide the gas passage and heat source required for heating regeneration and cold blowing cooling of the adsorption drying tank in the regeneration state in the dual adsorption drying unit, so as to realize the desorption and regeneration of the adsorbent. The purification output unit is connected in series with the air outlet pipe to filter out trace dust particles carried in the dried compressed air and to automatically discharge the filtered particles periodically. The detection units are respectively installed on the air inlet pipe, the air outlet pipe, the dual adsorption drying unit and the regeneration heating unit, and are used to detect the pressure, temperature and compressed air dew point parameters in real time during the operation of the device; The intelligent control unit is electrically connected to the gas-liquid separation unit, the dual adsorption drying unit, the regeneration heating unit, the purification output unit, and the detection unit, respectively. It is used to receive feedback signals from the detection unit, automatically control the operating status of each component, and realize intelligent energy-saving control of the device.

2. The energy-saving compressed air drying and purification device according to claim 1, characterized in that: The gas-liquid separation unit includes a gas-liquid separator connected in series on the air inlet pipe. The gas-liquid separator is a cyclone filter type gas-liquid separator, and an automatic drain valve is connected to the bottom of the gas-liquid separator.

3. The energy-saving compressed air drying and purification device according to claim 1, characterized in that: The dual adsorption drying unit includes a first adsorption drying tank and a second adsorption drying tank arranged in parallel. The air inlets of the first adsorption drying tank and the second adsorption drying tank are respectively connected to the air outlet of the gas-liquid separation unit through a first air inlet control valve and a second air inlet control valve. The air outlets are respectively connected to the air outlet pipeline through a first one-way valve of the dried output pipeline and a second one-way valve of the dried output pipeline. The regeneration exhaust port is respectively connected to the muffler through a first regeneration gas consumption proportional adjustment valve, a second regeneration gas consumption proportional adjustment valve, a first quick release valve, and a second quick release valve. The diameters of the first regeneration gas consumption proportional adjustment valve and the second regeneration gas consumption proportional adjustment valve are both smaller than the diameters of the first air inlet control valve and the second air inlet control valve.

4. The energy-saving compressed air drying and purification device according to claim 1, characterized in that: The regeneration heating unit includes a pipeline heater, a heating control valve, a cold blowing control valve, a first regeneration pipeline check valve, and a second regeneration pipeline check valve. The inlet of the heating control valve is connected to the outlet pipeline, and the outlet is connected to the inlet of the pipeline heater. The inlet of the cold blowing control valve is connected to the outlet pipeline. After the outlets of the pipeline heater and the cold blowing control valve merge, they are connected to the dual adsorption drying unit through the first regeneration pipeline check valve and the second regeneration pipeline check valve, respectively. The diameter of the heating control valve is smaller than the diameter of the cold blowing control valve.

5. The energy-saving compressed air drying and purification device according to claim 1, characterized in that: The purification output unit includes a self-cleaning filter connected in series on the outlet pipeline, and an automatic discharge valve is connected to the bottom of the self-cleaning filter; the detection unit includes a pressure sensor for detecting the pressure of the inlet pipeline and the outlet pipeline, a temperature sensor for detecting the dual adsorption drying unit and the regeneration heating unit, and a dew point sensor for detecting the dew point of the compressed air in the outlet pipeline.

6. The energy-saving compressed air drying and purification device according to claim 1, characterized in that: The intelligent control unit includes an operation control cabinet, which contains a PLC controller and an HMI operation interface. The PLC controller is used to control the operating status of each unit, and the HMI operation interface is configured to display the device flowchart, valve status, outlet temperature, heater operating status, internal temperature of the two adsorption drying tanks, outlet dew point parameters, and equipment operating, alarm, and shutdown status.

7. The energy-saving compressed air drying and purification device according to claim 3, characterized in that: The first and second adsorption drying tanks are filled with a regenerable desiccant, which is activated alumina or a mixture of molecular sieve and activated alumina.

8. The control method of the energy-saving compressed air drying and purification device according to any one of claims 1-7, characterized in that... Includes the following steps: S1. Adsorption and Drying Stage: The PLC controller controls one of the adsorption and drying tanks as the working tank and the other as the backup tank. After the wet compressed air enters the gas-liquid separator through the air inlet pipeline to separate liquid water and coarse particles, it enters the working tank through the corresponding air inlet control valve. After the desiccant in the tank adsorbs the moisture, the dried compressed air enters the outlet pipeline through the corresponding drying output pipeline check valve, and is then filtered by the self-cleaning filter before being output. S2, Dew Point Detection and Switching Stage: The dew point sensor detects the dew point value of the compressed air in the outlet pipeline in real time. When the detected dew point value drops to the preset switching threshold, the PLC controller automatically completes the switching between the working tank and the standby tank. The original working tank becomes the standby tank, and the original standby tank becomes the new working tank. S3, Standby Tank Regeneration Stage: After switching, the standby tank undergoes four processes in sequence: rapid unloading, heating, cold blowing, and pressurization to complete the regeneration of the adsorbent; S4. Seasonal Adaptive Control Stage: The PLC controller automatically selects the spring / summer control mode or the autumn / winter control mode based on the ambient air humidity, and adaptively adjusts the working / standby tank switching cycle, heating time, and cold blowing time parameters in different modes.

9. The energy-saving compressed air drying and purification device according to claim 8, characterized in that: In step S2, the preset switching threshold is -20℃; when the dew point value detected by the dew point sensor (16) is ≤-40℃, the device maintains the current working state; In step S3, during the heating process, the PLC controller controls the opening degree of the corresponding regeneration gas consumption proportional adjustment valve to 25%, and during the cold blowing process, it controls the opening degree of the corresponding regeneration gas consumption proportional adjustment valve to 50%.

10. The energy-saving compressed air drying and purification device according to claim 8, characterized in that: In step S3 The quick unloading process is as follows: the PLC controller controls the quick unloading valve corresponding to the spare tank to open, so that the pressure inside the tank drops from the working pressure to atmospheric pressure within a few seconds; The heating process is as follows: The PLC controller turns on the pipeline heater, opens the heating control valve, closes the cold blowing control valve, and controls the opening degree of the corresponding regeneration gas consumption ratio regulating valve to 25%, so that 2%-3% of the rated flow of dry compressed air in the outlet pipeline is heated and enters the standby tank to exchange heat with the adsorbent to remove moisture. The heating time is 1-2 hours. The cold blowing process is as follows: the PLC controller shuts off the pipeline heater and heating control valve, opens the cold blowing control valve, controls the opening degree of the corresponding regeneration gas consumption ratio regulating valve to 50%, so that 3%-5% of the rated flow of dry compressed air in the outlet pipeline enters the spare tank to cool the adsorbent and further desorb moisture. The cold blowing time is 15-20 minutes. The pressurization process is as follows: the PLC controller closes the corresponding regeneration gas consumption ratio regulating valve, keeps the cold blowing control valve open, and allows compressed air from the outlet pipeline to enter the standby tank until the pressure inside the tank is balanced with the pressure inside the working tank, at which point the standby tank enters the standby switching state.

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