Heat adsorption type drying machine with three-tower structure and adsorption regeneration process of heat adsorption type drying machine

Abstract

The invention discloses a heat adsorption type drying machine with a three-tower structure and an adsorption regeneration technology of the heat adsorption type drying machine, and belongs to the technical field of adsorption type drying machines. The dryer comprises three adsorption towers, a regeneration system and a PLC control system, adsorbents are arranged in the adsorption towers, and the regeneration system comprises an electric heater and an air blower which are connected through a steel pipe. According to the dryer, the purpose of saving energy is achieved through the peak-valley-flat electricity price, the adsorption tower A, the adsorption tower B and the adsorption tower C conduct adsorption in the daytime, the regeneration and cold blowing process is conducted when the valley electricity price is utilized, and therefore the operation cost of the dryer is reduced; the adsorption regeneration process comprises two working modes: in the first working mode, adsorption is carried out for 12 hours in a tower A, adsorption is carried out for 12 hours in a tower B, and adsorption is carried out alternately in a tower C; and a second working mode: one tower performs adsorption work, one tower performs heating regeneration, and the other tower can perform cold blowing. The adsorption dryer with the three-tower structure can meet the requirement of a customer for reasonably selecting an off-peak electricity period for heating regeneration, so that the operation electric energy of equipment is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of adsorption dryers, in particular to a three-tower structured heat adsorption dryer and an adsorption regeneration process thereof. Background Art

[0002] At present, we are deeply promoting the construction of ecological civilization and green and low-carbon development.

[0003] Electricity is a vital secondary energy source, playing an immeasurable role in social progress and people's lives. While electricity is a clean energy source, it is currently primarily generated through thermal power, which consumes significant amounts of coal. As my country's economy continues to develop, electricity consumption is also increasing. Furthermore, compared to developed countries, my country's electricity utilization rate is significantly insufficient. Therefore, conserving energy and achieving sustainable development have become paramount priorities for my country.

[0004] Currently, to encourage electricity users to rationally schedule their electricity use and improve the efficiency of electricity resources, the 24-hour day is divided into four periods: peak, off-peak, and off-peak. To calculate electricity consumption and charges for different periods, smart meters are configured with these periods in accordance with regulations. Low-voltage users are subject to time-of-use electricity pricing, including residential peak-off-peak pricing, general industrial and commercial pricing, and clean energy heating peak-off-peak pricing.

[0005] Traditional (thermal) regenerative adsorption dryers utilize two adsorption towers operating in alternating cycles. These towers are comprised of an electric heater system, switching valves, and a control system. Throughout the entire operating cycle, one tower is engaged in adsorption while the other is engaged in regeneration and desorption. However, a drawback of these traditional two-tower systems is that they lack the ability to control adsorption and regeneration based on peak, valley, and flat electricity prices. Summary of the Invention

[0006] The purpose of the present invention is to provide a three-tower structure heat adsorption dryer and an adsorption regeneration process thereof. The three-tower structure adsorption dryer can meet the customer's reasonable choice of off-peak power period for heating regeneration, thereby greatly reducing the equipment operating power.

[0007] To achieve the above object, the technical solutions adopted by the present invention are as follows:

[0008] A three-tower heat adsorption dryer includes adsorption tower A, adsorption tower B, adsorption tower C and a regeneration system. Each adsorption tower has a bed layer filled with adsorbent, and the regeneration system includes an electric heater and a blower connected thereto.

[0009] The bottoms of the adsorption towers A, B and C are connected to the main air intake pipe through the air intake pipes A, B and C respectively; low-temperature compressed air is fed into the adsorption towers A, B and C through the main air intake pipe and then through the air intake pipes A, B and C respectively; the air intake pipes A, B and C are respectively provided with main air intake valves AⅠ, AⅡ and AⅢ;

[0010] The tops of the adsorption towers A, B and C are connected to the main outlet pipe via outlet pipes A, B and C, respectively. Outlet pipes A, B and C are provided with outlet valves DⅠ, DⅡ and DⅢ, respectively. After the low-temperature compressed air is adsorbed by the adsorption towers, the dry and clean air is output from the tops of the adsorption towers through the main outlet pipe and is output to the downstream of the product gas via a post-dust removal filter.

[0011] The air inlet pipes A, B and C connected to the adsorption towers A, B and C are all provided with pressure reducing valves (respectively, pressure reducing valve CⅠ, pressure reducing valve CⅡ and pressure reducing valve CⅢ); after the bed layer (filled with adsorbent) in the adsorption tower is saturated with adsorption, the pressure can be reduced to ambient pressure through the pressure reducing valves.

[0012] In the regeneration system, the air outlet of the blower is connected to the air inlet of the electric heater through a steel pipe; the air outlet of the electric heater is connected to the regeneration gas main line, and the regeneration gas main line is connected to the outlet pipe A, the outlet pipe B and the outlet pipe C respectively through the regeneration branch pipe A, the regeneration branch pipe B and the regeneration branch pipe C;

[0013] The regeneration branch pipe A, the regeneration branch pipe B and the regeneration branch pipe C are respectively provided with a regeneration intake valve EⅠ, a regeneration intake valve EⅡ and a regeneration intake valve EⅢ.

[0014] In the regeneration system, a blower introduces ambient air from the outside and heats it to above 180°C through an electric heater to obtain regeneration gas, which provides energy for decomposing the adsorbent (adsorbent regeneration). The regeneration gas enters each adsorption tower (adsorption tower A, adsorption tower B, adsorption tower C) from the top of the adsorption tower after passing through the regeneration gas main line, each regeneration branch pipe and each outlet pipe. As the hot air flows through the bed filled with adsorbent, the adsorbent is desorbed at high temperature, and water molecules are released from the adsorbent and discharged into the atmosphere along with the regeneration gas (the inlet pipe A, the inlet pipe B and the inlet pipe C are respectively connected to the tower bottom discharge main line through discharge branch pipes, and each discharge branch pipe is correspondingly provided with a regeneration discharge valve BⅠ, a regeneration discharge valve BⅡ and a regeneration discharge valve BⅢ; the regeneration gas is output from the bottom of the tower through each discharge branch pipe to the tower bottom discharge main line, and then discharged into the atmosphere).

[0015] The main air outlet pipe is also connected to the air outlet pipe A, the air outlet pipe B and the air outlet pipe C respectively through the cold blow pipe A, the cold blow pipe B and the cold blow pipe C, and the cold blow pipe A, the cold blow pipe B and the cold blow pipe C are all provided with cold blow valves (cold blow valve FⅠ, cold blow valve FⅡ and cold blow valve FⅢ respectively); after the heating regeneration stage is completed, the electric heater stops working; part of the finished gas (dry, clean, room temperature air) is drawn from the equipment outlet (main air outlet) through the cold blow pipe (cold blow pipe A, cold blow pipe B and cold blow pipe C) and enters each adsorption tower from the top of the tower to perform cold blowing on the adsorbent bed, take away the heat of the adsorbent in the tower, and then pass through each discharge branch pipe to the main discharge line at the bottom of the tower, and then discharged into the atmosphere.

[0016] The dryer also includes a PLC control system; the adsorption tower A, adsorption tower B and adsorption tower C are all equipped with a dew point analyzer, which outputs a 4-20mA current to the PLC control system for program judgment. If the dew point is better than the set value, the adsorption tower undergoing the heating and regeneration process will be in a standby state, extending the operating time of the adsorption tower undergoing the adsorption process until the dew point reaches the set value, and the states of the two adsorption towers are switched.

[0017] The adsorption regeneration process using a three-tower hot adsorption dryer is as follows: the dryer uses peak-valley and flat electricity prices to achieve energy conservation. During the day, adsorption tower A, adsorption tower B or adsorption tower C is used for adsorption, and regeneration and cold blowing are carried out during valley electricity prices, thereby reducing the operating cost of the equipment. The adsorption regeneration process includes two working modes. The first working mode is: Tower A adsorbs for 12 hours, Tower B adsorbs for 12 hours, and Tower C adsorbs in rotation. The second working mode is: one tower is working for adsorption, one tower is heated for regeneration, and the other tower can be cold-blown.

[0018] Furthermore, the adsorption regeneration process specifically includes the following steps:

[0019] (1) Adsorption:

[0020] Low-temperature compressed air enters the adsorption tower from the bottom through the main air inlet pipe. The adsorbent in the adsorption tower uses its physical properties to absorb water vapor in the saturated compressed air. Dry and clean air leaves the adsorption tower from the top and is output to the downstream of the product gas through the post-dust removal filter. The adsorbent loading amount is determined by the adsorption capacity of the working cycle.

[0021] (2) Blood pressure reduction:

[0022] After the adsorption tower bed is saturated with adsorption, the pressure is reduced to ambient pressure through a pressure reducing valve;

[0023] (3) Heating regeneration:

[0024] After the pressure reduction is completed, the blower will heat the ambient air introduced from the outside to above 180℃ through the electric heater to provide energy for decomposing the adsorbent. The heated regeneration gas enters the adsorption tower from the top for the regeneration process. As the hot air flows through the desiccant bed, the adsorbent is desorbed at high temperature, and water molecules are released from the adsorbent and discharged into the atmosphere with the regeneration gas. When the regeneration discharge temperature (the temperature inside the adsorption tower) reaches the set value, the heating regeneration is completed.

[0025] (3) Cold blowing: After the heating regeneration stage is completed, the adsorbent bed needs to be cold-blown to reduce the temperature. The heater stops working, and part of the finished gas is introduced from the top of the equipment outlet into the adsorption tower, taking away the heat of the adsorbent in the tower and discharging it into the atmosphere. When the regeneration discharge temperature (the temperature inside the adsorption tower) reaches the set value, the cold blowing process ends.

[0026] (4) Boost:

[0027] After the cold blow is completed, the adsorption tower increases the pressure through the cold blow valve, and the pressure rises to the pipeline pressure, preparing for the adsorption tower to switch to the adsorption process.

[0028] Furthermore, after step (5), when the adsorption tower switches to the adsorption process, the saturated wet air passes through the two adsorption towers at the same time to ensure that the temperature and dew point of the outlet product gas are stable.

[0029] Furthermore, after step (4) of boosting, the PLC performs program judgment and sets the time to control the switching of the three towers according to the dew point value or different electricity price periods (peak period, valley period, flat period); when switching according to the dew point value, specifically: the dew point analyzer outputs 4-20mA current to the PLC for program judgment. If the dew point is better than the set value, the adsorption tower will be in standby state, and the adsorption time sequence will be extended until the dew point reaches the set value, and the three towers will switch.

[0030] The design mechanism and beneficial effects of the present invention are as follows:

[0031] 1. The present invention has designed a continuously operating three-tower heat-regenerating adsorption dryer. Its design primarily utilizes peak-valley and flat-peak electricity prices to achieve energy conservation. During the day, towers A and B perform adsorption, while regeneration and cold-blowing processes are performed during off-peak electricity prices. This can significantly reduce the operating costs of the equipment. The first operating mode: Tower A adsorbs for 12 hours, Tower B adsorbs for 12 hours, and Tower C adsorbs in rotation. The second operating mode: One tower is in adsorption operation, one tower is heated and regenerated, and the other tower can be cold-blown. The dryer mainly consists of three adsorption towers and adsorbents within the towers. The regeneration system consists of one or two electric heaters and one or two blowers, and the connecting pipes are steel pipes.

[0032] 2. This invention incorporates 18 main valve groups to control the flow of compressed air in each process. After the previous process is completed, the next process begins. The entire dryer is controlled by a fully automatic PLC system, ensuring fully automated and continuous operation.

[0033] 3. The control system of the present invention can accurately save energy by controlling the temperature of the regeneration process; it can also select dew point control / conventional time control according to the operating conditions, the product gas quality is intuitive and readable, and energy saving is maximized. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of the structure of a three-tower heat adsorption dryer according to the present invention.

[0035] Figure 2 The figure is a schematic diagram of the adsorption drying process of the three-tower structure heat adsorption dryer of the present invention.

[0036] In the figure: 100-adsorption tower A; 200-adsorption tower B, 300-adsorption tower C; 400-regeneration system; 401-blower; 402-electric heater; 403-regeneration gas main line; 500-main air inlet pipe; 600-main air outlet pipe; 700-discharge main line. DETAILED DESCRIPTION

[0037] The present invention provides a three-tower structure heat adsorption dryer, such as Figure 1 As shown, the dryer includes adsorption towers A100, B200, and C300, along with a regeneration system 400. Each tower contains a bed of adsorbent, which has the basic property of decreasing adsorption rate with increasing temperature and increasing with increasing pressure. The regeneration system 400 includes an electric heater 402 and a blower 401, with the blower outlet connected to the electric heater inlet via a steel pipe.

[0038] The bottoms of the adsorption tower A, the adsorption tower B and the adsorption tower C are respectively connected to the main air intake pipe 500 through the air intake pipe A, the air intake pipe B and the air intake pipe C, and the air intake pipe A, the air intake pipe B and the air intake pipe C are respectively provided with a main air intake valve AⅠ, a main air intake valve AⅡ and a main air intake valve AⅢ; the compressed air to be treated is respectively input into the adsorption tower A, the adsorption tower B and the adsorption tower C through the main air intake pipe 500 through the air intake pipe A, the air intake pipe B and the air intake pipe C.

[0039] The tops of the adsorption towers A, B and C are connected to the main outlet pipe 600 through outlet pipes A, B and C, respectively. Outlet pipes A, B and C are provided with outlet valves DⅠ, DⅡ and DⅢ, respectively. After the compressed air to be treated fully contacts the adsorbent in the tower, the water vapor in the compressed air diffuses onto the adsorbent and is adsorbed due to van der Waals attraction. The dry and clean air is output from the top of the adsorption tower through the main outlet pipe 600, filtered through a post-dust removal filter, and then output to the rear-end gas usage point.

[0040] The air inlet pipes A, B and C connected to the adsorption towers A, B and C are also respectively provided with a pressure reducing valve CⅠ, a pressure reducing valve CⅡ and a pressure reducing valve CⅢ (each pressure reducing valve is arranged near the bottom of the adsorption tower); after the adsorbent in each adsorption tower is saturated with adsorption, the air pressure in the tower can be reduced to the ambient pressure by opening the corresponding pressure reducing valves (pressure reducing valve CⅠ, pressure reducing valve CⅡ, pressure reducing valve CⅢ) of each tower.

[0041] In the regeneration system 400, the outlet end of the electric heater 402 is connected to the regeneration gas main line 403, which is then connected to the outlet pipes A, B, and C through the regeneration branch pipes A, B, and C, respectively. The regeneration branch pipes A, B, and C are respectively equipped with a regeneration intake valve EⅠ, a regeneration intake valve EⅡ, and a regeneration intake valve EⅢ.

[0042] When the adsorbent in the tower reaches saturation, it needs to be regenerated. This method uses ambient air (or finished gas reduced to atmospheric pressure) heated as regeneration gas (if finished gas is used, the pressure and temperature changes make the regeneration gas drier). The regeneration gas then flows through the depressurized adsorbent bed to be regenerated (i.e., the adsorption tower is already saturated). The high-temperature regeneration gas removes moisture from the adsorbent and carries it out of the dryer. The process is as follows:

[0043] In the regeneration system, a blower introduces ambient air from the outside and heats it to above 180°C through an electric heater to provide energy for decomposing the adsorbent (adsorbent regeneration). The heated regenerated gas passes through the regeneration gas main line 403 and then through each regeneration branch pipe (regeneration branch pipe A, regeneration branch pipe B and / or regeneration branch pipe C), each outlet pipe (outlet pipe A, outlet pipe B, outlet pipe C) to enter each adsorption tower (adsorption tower A, adsorption tower B, adsorption tower C). At this time, the outlet valves (outlet valve DⅠ, outlet valve DⅡ, outlet valve DⅢ) connected to the corresponding tower are closed and the regeneration inlet valves (regeneration inlet valve EⅠ, regeneration inlet valve EⅡ and regeneration inlet valve EⅢ) are opened; as the hot air flows through the bed filled with adsorbent, the adsorbent is desorbed at high temperature, water molecules are released from the adsorbent, and discharged into the atmosphere along with the regeneration gas. The regeneration emission reaches the set value, and the heating regeneration is completed. The specific discharge process of the regenerated gas with adsorbed water molecules is as follows: the air inlet pipe A, the air inlet pipe B and the air inlet pipe C are respectively connected to the tower bottom discharge main line 700 through discharge branch pipes, and each discharge branch pipe is correspondingly provided with a regeneration discharge valve BⅠ, a regeneration discharge valve BⅡ and a regeneration discharge valve BⅢ; each regeneration discharge valve is opened, and the regeneration gas with adsorbed water molecules is output from the bottom of the tower through each discharge branch pipe to the tower bottom discharge main line, and then discharged into the atmosphere.

[0044] The main gas outlet pipe 600 is further connected to the gas outlet pipe A, gas outlet pipe B and gas outlet pipe C respectively through the cold blow pipe A, cold blow pipe B and cold blow pipe C, and the cold blow valves FⅠ, FⅡ and FⅢ are respectively provided on the cold blow pipe A, cold blow pipe B and cold blow pipe C; after the heating regeneration stage is completed, the electric heater stops working and the adsorbent bed needs to be cold-blown; the cold blow valves (cold blow valve FⅠ, cold blow valve FⅡ and cold blow valve FⅢ) are opened, and part of the finished gas ( Dry, clean, room-temperature air passes through the cold blow pipes (cold blow pipe A, cold blow pipe B, and cold blow pipe C) and the outlet pipes, then enters each adsorption tower from the top, cool-blowing the adsorbent bed and removing heat from the adsorbent. It then passes through the discharge branches (each equipped with regeneration discharge valve A, regeneration discharge valve B, and regeneration discharge valve C, which are opened during cold blowing) to the main discharge line 700 at the bottom of the tower, where it is discharged into the atmosphere. Once the regeneration discharge reaches the set value, the cold blow process ends. After the cold blow is complete, the pressure in each adsorption tower is increased through the cold blow valve to the network pressure.

[0045] The adsorption tower A, adsorption tower B and adsorption tower C are all equipped with a dew point analyzer, which outputs a 4-20mA current to the PLC control system for program judgment. If the dew point is better than the set value, the adsorption tower performing the heating and regeneration process will be in a standby state, extending the operation time of the adsorption tower performing the adsorption process until the dew point reaches the set value, and the states of the two adsorption towers are switched.

[0046] The adsorption dehydration of the adsorption tower in the present invention adopts the principle of physical adsorption, and utilizes the basic characteristics that the adsorption rate of the adsorbent in the tower decreases with increasing temperature and increases with increasing pressure to create a low-temperature and high-pressure adsorption environment and a high-temperature and low-pressure regeneration environment.

[0047] The present invention utilizes the above three-tower structure to carry out adsorption regeneration process with a heat adsorption dryer. Figure 2 As shown. The adsorption regeneration process is as follows: the dryer uses peak-valley and flat electricity prices to achieve energy conservation. During the day, adsorption tower A, adsorption tower B, and / or adsorption tower C perform adsorption, and regeneration and cold blowing are performed during off-peak electricity prices, thereby reducing the operating cost of the equipment. The adsorption regeneration process includes two working modes. The first working mode: Tower A adsorbs for 12 hours, Tower B adsorbs for 12 hours, and Tower C adsorbs in rotation. The second working mode: One tower is working for adsorption, one tower is heated for regeneration, and the other tower can be cold-blown. The specific adsorption regeneration process is as follows:

[0048] (1) Adsorption:

[0049] Low-temperature compressed air enters the adsorption tower from the bottom through the main air inlet pipe. The adsorbent in the adsorption tower uses its physical properties to absorb water vapor in the saturated compressed air. Dry and clean air leaves the adsorption tower from the top and is output to the downstream of the product gas through the post-dust removal filter. The adsorbent loading amount is determined by the adsorption capacity of the working cycle.

[0050] (2) Blood pressure reduction:

[0051] After the adsorption tower bed is saturated with adsorption, the pressure is reduced to ambient pressure through a pressure reducing valve;

[0052] (3) Heating regeneration:

[0053] After the pressure reduction is completed, the blower will heat the ambient air introduced from the outside to above 180℃ through the electric heater to provide energy for decomposing the adsorbent. The heated regeneration gas enters the adsorption tower from the top for the regeneration process. As the hot air flows through the desiccant bed, the adsorbent is desorbed at high temperature, and water molecules are released from the adsorbent and discharged into the atmosphere with the regeneration gas. When the regeneration discharge temperature (the temperature inside the adsorption tower) reaches the set value, the heating regeneration is completed.

[0054] (3) Cold blowing: After the heating regeneration stage is completed, the adsorbent bed needs to be cold-blown to reduce the temperature. The heater stops working, and part of the finished gas is introduced from the top of the equipment outlet into the adsorption tower, taking away the heat of the adsorbent in the tower and discharging it into the atmosphere. When the regeneration discharge temperature (the temperature inside the adsorption tower) reaches the set value, the cold blowing process ends.

[0055] (4) Boost:

[0056] After the cold blow is completed, the adsorption tower increases the pressure through the cold blow valve, and the pressure rises to the pipeline pressure, preparing for the adsorption tower to switch to the adsorption process.

[0057] Furthermore, after step (5), when the adsorption tower switches to the adsorption process, the saturated wet air passes through the two adsorption towers at the same time to ensure that the temperature and dew point of the outlet product gas are stable.

[0058] Furthermore, after step (4) of boosting, the PLC performs program judgment and sets the time to control the switching of the three towers according to the dew point value or different electricity price periods (peak period, valley period, flat period); when switching according to the dew point value, specifically: the dew point analyzer outputs 4-20mA current to the PLC for program judgment. If the dew point is better than the set value, the adsorption tower will be in standby state, and the adsorption time sequence will be extended until the dew point reaches the set value, and the three towers will switch.

[0059] Example 1:

[0060] This embodiment is an adsorption regeneration process of a three-tower structure with a heat adsorption dryer. This embodiment follows the dew point control mode. The specific process is as follows (there is an indicator position when the regeneration of the three adsorption towers is completed. The factory initial position completes the regeneration of Tower A):

[0061] 1. (Tower A completes regeneration, but Towers B and C do not complete regeneration) Tower A adsorbs for 12 hours, Tower B regenerates, and Tower B regenerates after the regeneration of Tower C is completed.

[0062] 2. (Tower B completes regeneration, but Towers A and C do not complete regeneration) Tower B adsorbs for 12 hours, Tower A regenerates, and when Tower A regenerates, Tower C regenerates.

[0063] 3. (Tower C completes regeneration, but Towers A and B do not complete regeneration) Tower C adsorbs for 12 hours, Tower A regenerates, and when Tower A regenerates, Tower B regenerates.

[0064] 4. (Tower A completes regeneration, Tower B completes regeneration, but Tower C does not complete regeneration) Tower A adsorbs for 12 hours, Tower C regenerates, and if the dew point of Tower A does not meet the requirements, the adsorption is switched to Tower B. Tower A clears the regeneration completion indication, and when Tower C completes regeneration, the regeneration is switched to Tower A.

[0065] 5. (Tower A completes regeneration, Tower B completes regeneration, but Tower C does not complete regeneration) Tower A adsorbs for 12 hours, Tower C regenerates, and if the dew point of Tower A does not meet the requirements, the adsorption is switched to Tower B. Tower A clears the regeneration completion indication, and when Tower C completes regeneration, the regeneration is switched to Tower A.

[0066] 6. (Tower A completes regeneration, Tower C completes regeneration, but Tower B does not complete regeneration) Tower A adsorbs for 12 hours, Tower B regenerates, and if the dew point of Tower A does not meet the requirements, the adsorption is switched to Tower C. Tower A clears the regeneration completion indication, and after Tower B regenerates, the regeneration is switched to Tower A.

[0067] 7. (Tower B completes regeneration, Tower C completes regeneration, but Tower A does not complete regeneration) Tower B adsorbs for 12 hours, Tower A regenerates, and if the dew point of Tower B does not meet the requirements, the adsorption process switches to Tower C. Tower B clears the regeneration completion indication, and when Tower A completes regeneration, the process switches to Tower B.

[0068] 8. If the dew point of any of the three towers ABC does not meet the standard during adsorption and the adsorption tower has not completed regeneration, no switching will be performed.

[0069] 9. If the dew point of any of the three towers ABC does not meet the standard during adsorption, and the adsorption towers that have completed regeneration are switched in sequence, as shown in 9.1-9.3:

[0070] 9.1. Tower A is adsorbing, but the dew point does not meet the standard. Tower BC completes regeneration and switches to Tower B for adsorption. Tower A eliminates the regeneration completion indication and enters the regeneration process.

[0071] 9.2. Tower B adsorbs, but the dew point does not meet the standard. Tower AC completes regeneration and switches to Tower A for adsorption. Tower B eliminates the regeneration completion indication and enters the regeneration process.

[0072] 9.3. Tower C adsorbs, the dew point does not meet the standard, towers AB complete regeneration, and switch to tower A for adsorption. Tower C eliminates the regeneration completion indication and enters the regeneration process.

[0073] Example 2:

[0074] This embodiment is an adsorption regeneration process of a three-tower structure with a heat adsorption dryer, which is controlled in a time mode. The specific process is as follows (in the time mode, the dew point temperature is only used for display and does not participate in the switching tower operation of the program. The switching towers are switched according to the time setting):

[0075] 1. The switching order is tower A adsorption, tower B regeneration, tower C waiting for regeneration;

[0076] 2. Tower A adsorbs, Tower B regenerates and switches to the adsorption state, and Tower C regenerates;

[0077] 3. Tower A adsorption is completed and then turns to waiting for regeneration, Tower B adsorption, Tower C regeneration is completed and then turns to waiting for adsorption;

[0078] 4. Tower A regenerates, Tower B adsorbs, and Tower C regenerates and turns to adsorption;

[0079] 5. Tower A regeneration is completed and it turns to adsorption, Tower B adsorption is completed and it turns to regeneration, Tower C adsorption;

[0080] 6. Tower A is waiting for adsorption, Tower B is regenerating, and Tower C is adsorbing.

Claims

1. A three-tower heat adsorption dryer, characterized in that: The dryer comprises an adsorption tower A, an adsorption tower B, an adsorption tower C and a regeneration system. Each adsorption tower has a bed layer filled with adsorbent, and the regeneration system comprises an electric heater and a blower connected thereto.

2. The three-tower heat adsorption dryer according to claim 1, characterized in that: The bottoms of the adsorption towers A, B and C are connected to the main air intake pipe through the air intake pipes A, B and C respectively; low-temperature compressed air is fed into the adsorption towers A, B and C through the main air intake pipe and then through the air intake pipes A, B and C respectively; the air intake pipes A, B and C are respectively provided with main air intake valves AⅠ, AⅡ and AⅢ; The tops of the adsorption towers A, B and C are connected to the main outlet pipe via outlet pipes A, B and C, respectively. Outlet pipes A, B and C are provided with outlet valves DⅠ, DⅡ and DⅢ, respectively. After the low-temperature compressed air is adsorbed by the adsorption towers, the dry and clean air is output from the tops of the adsorption towers through the main outlet pipe and is output to the downstream of the product gas via a post-dust removal filter. The air inlet pipes A, B and C connected to the adsorption towers A, B and C are all provided with pressure reducing valves (respectively, pressure reducing valve CⅠ, pressure reducing valve CⅡ and pressure reducing valve CⅢ); after the bed layer (filled with adsorbent) in the adsorption tower is saturated with adsorption, the pressure can be reduced to ambient pressure through the pressure reducing valves.

3. The three-tower heat adsorption dryer according to claim 2, characterized in that: In the regeneration system, the air outlet of the blower is connected to the air inlet of the electric heater through a steel pipe; the air outlet of the electric heater is connected to the regeneration gas main line, and the regeneration gas main line is connected to the outlet pipe A, the outlet pipe B and the outlet pipe C respectively through the regeneration branch pipe A, the regeneration branch pipe B and the regeneration branch pipe C; The regeneration branch pipe A, the regeneration branch pipe B and the regeneration branch pipe C are respectively provided with a regeneration intake valve EⅠ, a regeneration intake valve EⅡ and a regeneration intake valve EⅢ.

4. The three-tower heat adsorption dryer according to claim 3, characterized in that: In the regeneration system, a blower introduces ambient air from the outside and heats it to above 180°C through an electric heater to obtain regeneration gas. The regeneration gas enters each regeneration branch pipe through the regeneration gas main line, and then enters each adsorption tower (adsorption tower A, adsorption tower B, adsorption tower C) through each outlet pipe. As the hot air flows through the bed layer filled with adsorbent, the adsorbent is desorbed at high temperature, and water molecules are released from the adsorbent and discharged into the atmosphere along with the regeneration gas (the inlet pipe A, the inlet pipe B and the inlet pipe C are respectively connected to the tower bottom discharge main line through discharge branch pipes, and each discharge branch pipe is correspondingly provided with a regeneration discharge valve BⅠ, a regeneration discharge valve BⅡ and a regeneration discharge valve BⅢ; the regeneration gas is output from the bottom of the tower through each discharge branch pipe to the tower bottom discharge main line, and then discharged into the atmosphere).

5. The three-tower heat adsorption dryer according to claim 4, characterized in that: The main air outlet pipe is also connected to the air outlet pipe A, the air outlet pipe B and the air outlet pipe C respectively through the cold blow pipe A, the cold blow pipe B and the cold blow pipe C, and the cold blow pipe A, the cold blow pipe B and the cold blow pipe C are all provided with cold blow valves (cold blow valve FⅠ, cold blow valve FⅡ and cold blow valve FⅢ respectively); after the heating regeneration stage is completed, the electric heater stops working; part of the finished gas (dry, clean, room temperature air) is drawn from the equipment outlet (main air outlet) through the cold blow pipe (cold blow pipe A, cold blow pipe B and cold blow pipe C) and enters each adsorption tower from the top of the tower to perform cold blowing on the adsorbent bed, take away the heat of the adsorbent in the tower, and then pass through each discharge branch pipe to the main discharge line at the bottom of the tower, and then discharged into the atmosphere.

6. The three-tower heat adsorption dryer according to claim 1, characterized in that: The dryer also includes a PLC control system; the adsorption tower A, adsorption tower B and adsorption tower C are all equipped with a dew point analyzer, which outputs a 4-20mA current to the PLC control system for program judgment. If the dew point is better than the set value, the adsorption tower undergoing the heating and regeneration process will be in a standby state, extending the operating time of the adsorption tower undergoing the adsorption process until the dew point reaches the set value, and the states of the two adsorption towers are switched.

7. The adsorption regeneration process of the three-tower heat adsorption dryer according to claim 1, characterized in that: The adsorption regeneration process is as follows: the dryer uses peak-valley and flat electricity prices to achieve energy conservation. During the day, adsorption tower A, adsorption tower B and / or adsorption tower C perform adsorption, while regeneration and cold blowing processes are performed during off-peak electricity prices, thereby reducing the operating costs of the equipment. The adsorption regeneration process includes two working modes. The first working mode: Tower A adsorbs for 12 hours, Tower B adsorbs for 12 hours, and Tower C adsorbs in rotation. The second working mode: one tower is in adsorption operation, one tower is heated and regenerated, and the other tower can be cold-blown.

8. The adsorption regeneration process of the three-tower heat adsorption dryer according to claim 7, characterized in that: The adsorption regeneration process specifically includes the following steps: (1) Adsorption: Low-temperature compressed air enters the adsorption tower from the bottom through the main air inlet pipe. The adsorbent in the adsorption tower uses its physical properties to absorb water vapor in the saturated compressed air. Dry and clean air leaves the adsorption tower from the top and is output to the downstream of the product gas through the post-dust removal filter. The adsorbent loading amount is determined by the adsorption capacity of the working cycle. (2) Blood pressure reduction: After the adsorption tower bed is saturated with adsorption, the pressure is reduced to ambient pressure through a pressure reducing valve; (3) Heating regeneration: After the pressure reduction is completed, the blower will heat the ambient air introduced from the outside to above 180℃ through the electric heater to provide energy for decomposing the adsorbent. The heated regeneration gas enters the adsorption tower from the top for the regeneration process. As the hot air flows through the desiccant bed, the adsorbent is desorbed at high temperature, and water molecules are released from the adsorbent and discharged into the atmosphere with the regeneration gas. When the regeneration discharge temperature (the temperature inside the adsorption tower) reaches the set value, the heating regeneration is completed. (3) Cold blowing: After the heating regeneration stage is completed, the adsorbent bed needs to be cold-blown to reduce the temperature. The heater stops working, and part of the finished gas is introduced from the top of the equipment outlet into the adsorption tower, taking away the heat of the adsorbent in the tower and discharging it into the atmosphere. When the regeneration discharge temperature (the temperature inside the adsorption tower) reaches the set value, the cold blowing process ends. (4) Boost: After the cold blow is completed, the adsorption tower increases the pressure through the cold blow valve, and the pressure rises to the pipeline pressure, preparing for the adsorption tower to switch to the adsorption process.

9. The adsorption regeneration process of the three-tower heat adsorption dryer according to claim 8, characterized in that: After step (5), when the adsorption tower switches to the adsorption process, the saturated wet air passes through the two adsorption towers at the same time to ensure that the temperature and dew point of the outlet product gas are stable.

10. The adsorption regeneration process of the three-tower heat adsorption dryer according to claim 8, characterized in that: After step (4) voltage is increased, the PLC performs program judgment according to the dew point value or different electricity price periods (peak period, valley period, flat period) and sets the time to control the switching of the three towers; when switching according to the dew point value, the dew point analyzer outputs 4-20mA current to the PLC for program judgment. If the dew point is better than the set value, the regeneration tower will be in standby state, and the drying sequence will be extended until the dew point reaches the set value, and the three towers will switch.

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