Automatic cleaning system for biological desulfurization tower and control method of automatic cleaning system

Abstract

The invention discloses an automatic cleaning system of a biological desulfurization tower and a control method thereof, the lower part of the desulfurization tower is connected with a gas inlet header pipe with a control valve, and a spray head at the upper part of the desulfurization tower is connected with a circulating tank through a spray circulating pipe with a control valve and a circulating pump, so that the reverse flow of biogas and circulating liquid in the desulfurization tower is realized; a plurality of layers of fillers are arranged in the desulfurization tower, a connecting pipe with a spiral-flow aerator is arranged below the fillers in the middle layers, a connecting pipe with a jet aerator is arranged below the filler in the bottommost layer, the connecting pipes comprise a liquid inlet pipe and an air inlet pipe, the liquid inlet pipe is connected with a circulating tank, and the air inlet pipe is connected with a circulating fan, so that the fillers in the layers are independently cleaned; a plurality of blow-off pipes with control valves are arranged at the side part of the desulfurization tower and are directly connected to the circulating tank, so that the cleaning waste liquid is directly discharged to the circulating tank. The device has the characteristics of being convenient to operate, high in stability, beneficial to improving the filler cleaning efficiency and the like, and online automatic cleaning of the desulfurizing tower is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of biological desulfurization tower cleaning, and in particular to an automatic cleaning system for a biological desulfurization tower and a control method thereof. Background Art

[0002] Biotrickling filters are widely used in biogas desulfurization. This technology removes hydrogen sulfide from biogas through the bacteria on the surface of biological fillers. As the operating time increases, the number of bacteria on the surface of the biological fillers gradually increases. In addition, the sulfides produced by the biochemical reaction accumulate, and the fillers gradually become blocked, resulting in an increase in the pressure difference between the inlet and outlet of the desulfurization tower and a deterioration in the desulfurization effect. In order to improve the clogging problem of the fillers, the current main method is to discharge the circulating fluid after shutdown and manually unload all the fillers. After all the fillers are cleaned offline, they are loaded into the packing tower and re-filmed. The entire cleaning process not only requires a complete shutdown, consumes a lot of manpower to load and unload the fillers, but also requires secondary film cultivation of the cleaned fillers. The overall cleaning process requires a large amount of manual labor and a harsh working environment. The cleaning process is easy to damage the fillers and requires secondary film cultivation. The overall time-consuming process has a great impact on production.

[0003] Chinese patent application 201310420956.2 discloses a biodesulfurization tower packing flushing device and flushing method. The technical solution sets aeration pipes in each packing layer in the tower, uses air as the gas source, and cleans each packing layer from top to bottom. The cleaning gas source of this method is air, and the gas in the tower needs to be replaced before and after cleaning, which has certain safety hazards. The air introduced during the cleaning process will all become odorous gas, which needs to be collected and treated separately.

[0004] Chinese patent application 201611050303.X discloses an online cleaning device for biotrickling filter packing. The technical solution sets a cleaning nozzle and a gas pulser in the packing layer to clean the packing with air. Although it can be operated without stopping, it is only applicable to aerobic reactions and not to biogas environments.

[0005] Chinese patent application 202111212234.9 discloses a tower-type biological sedimentation filtration device, which uses a rotating brush to clean the filler and the inner wall, and separately sets up a sedimentation device for mixing reagents and removing sediment. This method can only clean the sides of the outer filler and the tank wall, and it is difficult to remove the middle filler and horizontal fouling substances.

[0006] Chinese patent application 201921349738.3 discloses a biogas biodesulfurization tower with a cleaning device. This technical solution uses hydraulic impact and air wiping cleaning methods to flush the tank wall and filler. The gas source used in this solution is still air. The tower body needs to be replaced with gas before and after the operation. The air introduced during the process will all become odorous gas, which needs to be collected and treated separately.

[0007] Chinese patent application 202321827291.2 discloses an anti-packing clogging biological tower. This technical solution sets a nozzle in the layered seasoning room and uses the nozzle to spray water to flush the packing fouling. This technical solution has a certain effect on pure biological fouling, but has poor removal ability for substances with strong adhesion, and the removal effect is limited by the number of nozzles and the service area, which is prone to uneven cleaning. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide an automatic cleaning system for a bio-desulfurization tower and a control method thereof, which are convenient to operate, highly stable and conducive to improving the cleaning efficiency of the filler, in view of the deficiencies in the prior art.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0010] A biological desulfurization tower automatic cleaning system comprises a desulfurization tower and a circulation tank, wherein the lower part of the desulfurization tower is connected to an air intake main pipe with a control valve so as to enable the biogas to flow from bottom to top in the desulfurization tower; a spray head is provided at the upper part of the desulfurization tower, and the spray head is connected to the circulation tank through a spray circulation pipe with a control valve and a circulation pump so as to enable the circulating liquid output from the circulation tank to flow from top to bottom in the desulfurization tower; multiple layers of fillers are provided inside the desulfurization tower, and connecting pipes with cyclone aerators are provided below the fillers located in the middle layers, and connecting pipes with jet aerators are provided below the fillers located in the bottom layer, and the connecting pipes comprise a liquid inlet pipe and an air inlet pipe, the liquid inlet pipe is connected to the circulation tank through a jet pump, and the air inlet pipe is connected to the circulation fan so as to enable separate cleaning of each layer of fillers; a plurality of sewage pipes with control valves are provided on the side of the desulfurization tower, and the sewage pipes are located below the aerators of each layer, and the sewage pipes are connected to the circulation tank so as to enable the cleaning waste liquid in the desulfurization tower to be directly discharged into the circulation tank.

[0011] As a further improvement of the present invention, the desulfurization tower is connected to the circulation tank through a connecting pipe, the connecting pipe includes two parallel branches, one of which is provided with a control valve, and the other branch is provided with a connecting pump and a control valve; the desulfurization tower discharges the circulating liquid to the circulation tank through the connecting pipe; the connecting pipe is provided with an air shield at the inlet of the desulfurization tower.

[0012] As a further improvement of the present invention, the outlet end of the circulation pump is divided into two branches, one of which is connected to the desulfurization tower through a spray circulation pipe, and the other branch returns to the circulation tank through a pipeline with a control valve and a filter.

[0013] As a further improvement of the present invention, the air inlet duct of the circulating fan is connected to the air outlet pipe at the top of the desulfurization tower, and a coarse filter and a fine filter are sequentially provided on the air inlet duct of the circulating fan. The gas discharged from the desulfurization tower enters the circulating fan after two-stage filtration.

[0014] As a further improvement of the present invention, in the desulfurization tower, a pressure sensor P and a contact liquid level switch L are provided between each layer of filler, and the contact liquid level switch L is located above the sewage pipe; a pressure sensor P and an oxygen detector O are provided on the air outlet pipe at the top of the desulfurization tower.

[0015] As a further improvement of the present invention, the air intake main pipe includes two branches, wherein the first branch is connected to the lower part of the desulfurization tower, and the second branch is connected to the override pipe at the top of the desulfurization tower, and an air supply pipe with a control valve is provided on the upper part of the override pipe, and the installation position of the air supply pipe on the upper part of the desulfurization tower is higher than the spray head.

[0016] As a general technical concept, the present invention also provides a control method suitable for the above-mentioned biological desulfurization tower automatic cleaning system, which automatically triggers the desulfurization tower to perform overall cleaning or bottom packing layer cleaning through the overall pressure difference or stratified pressure difference value in the desulfurization tower; when the pressure difference between the air inlet and outlet of the desulfurization tower is 0.3~1.5kPa and lasts for 12~72h, the overall cleaning is triggered; when the stratified pressure difference between the adjacent two side packing layers in the desulfurization tower is 0.2~1kPa and lasts for 6~48h, the cleaning of the bottom layer is triggered.

[0017] As a further improvement of the present invention, when the desulfurization tower is cleaned as a whole, the following steps are included:

[0018] Step S1, open the control valve on the outlet pipe at the top of the desulfurization tower, close the control valve on the air inlet main pipe, and start the oxygen detector O;

[0019] Step S2, close the control valve on the connecting pipe between the bottom of the desulfurization tower and the bottom of the circulation tank, keep the circulation pump normally open, and close the filter bypass where the filter is located;

[0020] Step S3: When the liquid level in the desulfurization tower rises to trigger the contact liquid level switch L above the second layer of filler, the circulation pump is turned off and the control valve on the outlet pipe is closed;

[0021] Step S4, open the control valve on the air supply pipe, open the control valve on the connecting pipe connected to the cyclone aerator under the second layer of filler, start the circulating fan, aerate and clean the second layer of filler, and control the aeration intensity at 0.5-1.5m 3 / m 2 ·min;

[0022] Step S5, after continuous aeration for 5 to 10 minutes, open and close the first drain valve from top to bottom on the side of the desulfurization tower for 5 to 10 seconds; after continuing aeration for 5 to 30 minutes, close the control valve and the circulating fan on the connecting pipe, open the second drain valve from top to bottom on the side of the desulfurization tower to drain the liquid, and when the liquid level in the desulfurization tower drops to the contact level switch L above the next layer of filler, close the second drain valve; after waiting for 5 to 30 minutes, start the drain pump to discharge the sewage in the circulation tank to the low liquid level;

[0023] Step S6, after the sewage pump stops, the liquid level in the circulation tank is automatically replenished, and the circulation pump is started to replenish water to the desulfurization tower, and steps S3 to S6 are repeated 0 to 3 times;

[0024] Step S7, after completing the repeated steps, the liquid level in the desulfurization tower is replenished to the position of the liquid level contact switch L above the bottom layer of filler, and the next layer of filler cleaning is started; when the next layer of filler is not the bottom layer, repeat steps S3 to S6, wherein the replenishing water level is correspondingly lowered to the position of the liquid level contact switch L above the cleaning layer filler, and the corresponding aeration connection control valve and the sewage valve are opened and closed; when the next layer of filler is the bottom layer, cleaning is performed according to the following steps;

[0025] Step S8, start the jet pump, open the control valve connected to the jet aerator, start the circulation fan, and control the aeration intensity at 1-2 m / s by controlling the valve. 3 / m 2 ·min, the gas-water ratio is controlled at 4-4.5;

[0026] Step S9, after continuous aeration for 5 to 15 minutes, open and close the drain valve above the bottom filler for 10 to 30 seconds; continue aeration for 5 to 10 minutes, stop the jet pump and the circulation fan, start the connecting pump to discharge the sewage in the desulfurization tower into the circulation tank, and turn off the connecting pump after the liquid level reaches the contact liquid level switch L position at the bottom of the desulfurization tower 1;

[0027] Step S10: After the circulation tank is left to stand for 10 to 30 minutes, start the sewage pump until the circulation tank reaches the low liquid level and then stop; after the circulation tank is replenished with water to the high liquid level, start the circulation pump to replenish the liquid level of the desulfurization tower to the contact liquid level switch L above the bottom filler of the desulfurization tower; repeat steps S8 and S9 1 to 3 times, in which the aeration intensity is changed to 0.5 to 1.5 m 3 / m 2 ·min, the aeration time is changed to 10 to 30 minutes;

[0028] Step S11: After the repetition is completed, the control valve connected to the jet aerator is opened, the jet pump, the circulating fan and the connecting pump are started, and the filtering circuit of the circulating pump is opened;

[0029] Step S12, after stopping aeration, open the drain valve on the first drain pipe from top to bottom on the side of the desulfurization tower for 5 to 10 seconds, keep the water supply valve of the circulation tank normally closed, start the drain pump, and use the liquid level of the circulation tank as the control point to open the drain valves of each drain pipe on the side of the desulfurization tower from top to bottom in sequence. When the drain valve of the second to last drain pipe from top to bottom on the side of the desulfurization tower is automatically closed, start the connecting pump to discharge the circulating liquid of the desulfurization tower into the circulation tank, and finally drain all the liquid in the circulation tank;

[0030] Step S13, after the whole machine is cleaned, the water supply valve of the circulation tank is restored to the liquid level linkage; after the circulation tank is replenished with liquid and bacteria, the circulation pump is started to replenish the desulfurization tower to the preset liquid level, the control valves on the air inlet main pipe and the air outlet pipe are started, and the control valve on the air supply pipe is closed.

[0031] As a further improvement of the present invention, when the bottom layer of the desulfurization tower is cleaned separately, the following steps are included:

[0032] Step Y1, open the control valve on the outlet pipe at the top of the desulfurization tower, close the control valve on the air inlet main pipe, and start the oxygen detector O;

[0033] Step Y2, close the control valve on the connecting pipe between the bottom of the desulfurization tower and the bottom of the circulation tank, keep the circulation pump normally open, and close the filter bypass where the filter is located;

[0034] Step Y3: When the liquid level in the desulfurization tower rises to trigger the liquid level contact switch L above the bottom packing, the circulation pump is turned off and the control valve on the outlet pipe is closed;

[0035] Step Y4, open the control valve on the air supply pipe, open the control valve on the aeration pipe connected to the jet aerator, start the jet pump and the circulation fan, and control the aeration intensity at 1-2m 3 / m 2 ·min, the gas-water ratio is controlled at 4-4.5;

[0036] Step Y5, after continuous aeration for 5 to 15 minutes, open the control valve of the sewage pipe above the bottom filler for 10 to 30 seconds; continue aeration for 5 to 10 minutes, turn off the jet pump and the circulation fan, start the connecting pump to drain water to the circulation tank, and turn off the connecting pump after the liquid level reaches the level contact switch L at the bottom of the desulfurization tower;

[0037] Step Y6, start the sewage pump to drain the circulating tank to the low liquid level and then stop; after the circulating tank is replenished to the high liquid level, start the circulating pump to replenish the desulfurization tower liquid level to the liquid level contact switch L at the bottom of the desulfurization tower; repeat steps Y4 and Y5 1 to 3 times, wherein the aeration intensity is changed to 0.5 to 1.5 m 3 / m 2 ·min, the aeration time is changed to 10 to 30 minutes;

[0038] Step Y7: After the circulation tank is replenished with liquid and bacteria, the circulation pump is started to replenish the desulfurization tower with liquid to the preset liquid level, the control valves on the air inlet main pipe and the air outlet pipe are opened, and the control valve on the air replenishment pipe is closed.

[0039] As a further improvement of the present invention, during the cleaning process, the oxygen detector O continuously monitors the circulating biogas in the desulfurization tower, and when the oxygen concentration is higher than 2.5%, an alarm is issued, and when the oxygen concentration is higher than 3%, the cleaning is automatically stopped.

[0040] Compared with the prior art, the advantages of the present invention are:

[0041] The automatic cleaning system and control method of the biological desulfurization tower of the present invention realizes the flow of biogas from bottom to top in the desulfurization tower by connecting an air inlet pipe with a control valve at the lower part of the desulfurization tower, and connects the spray head at the upper part of the desulfurization tower with the circulation tank through a spray circulation pipe with a control valve and a circulation pump, so that the circulating liquid flows from top to bottom in the desulfurization tower, which is exactly opposite to the flow direction of biogas. The circulating liquid is stirred by biogas, which is conducive to washing away the miscellaneous bacteria adhering to the surface of the filler; further, the desulfurization tower is provided with multiple layers of fillers, and a gas inlet pipe with a control valve is provided below the filler in the middle layer. The connecting pipe of the cyclone aerator is provided with a connecting pipe with a jet aerator under the bottom layer of the filler, the liquid inlet pipe in the connecting pipe is connected to the circulation tank, and the air inlet pipe in the connecting pipe is connected to the circulation fan. By pressurizing the cleaning to spray onto the filler, the filler cleaning effect is improved, and the aerator is close to the lower side of the filler, which can focus on cleaning the lower side of the filler; the side of the desulfurization tower is provided with a sewage pipe with a control valve, the sewage pipe is located below the aerators of each layer, and the sewage pipe is connected to the circulation tank, that is, the circulating liquid in the desulfurization tower is circulated to the circulation tank, which improves the utilization rate of the circulating liquid. The present invention can remove suspended matter during operation, and can realize layered cleaning of the filler and flushing of the scale on the tank wall without opening the tower to unload, and the cleaning process does not introduce air or other inert substances, and there is no need to replace the gas before and after cleaning, and the amount of odor generated during the process is extremely small. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the overall structural principle of the automatic cleaning system for the biological desulfurization tower in a specific embodiment of the present invention;

[0043] Legend: 1. Desulfurization tower; 2. Circulation tank; 3. Air intake main pipe; 4. Cyclone aerator; 5. Air supply pipe; 6. Coarse filter; 7. Fine filter; 8. Drain pipe; 9. Filter; 10. Jet aerator; 11. Air baffle; 12. Connecting pump; 13. Jet pump; 14. Drain pump; 15. Circulation pump; 16. Overrun pipe; 17. Sprinkler head; 18. Circulation fan; 19. Spray circulation pipe; 20. Exhaust pipe. DETAILED DESCRIPTION

[0044] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0045] In the description of the present invention, it should be understood that the terms "side", "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0046] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0047] Example 1

[0048] For the biological desulfurization trickling filter (referred to as "desulfurization tower"), 2 to 3 layers of fillers are generally set up in the tower, and the biogas passes from bottom to top, while the circulating liquid flows from top to bottom. Because the reaction is mainly concentrated in the lower filler and the lower side of each layer of filler, the fouling phenomenon of the lower filler is significantly higher than that of the upper filler, and the fouling of each layer of filler is mainly concentrated on the lower side. Therefore, online cleaning focuses on the cleaning of the lower filler and the lower side of each layer of filler. At the same time, in order to speed up the cleaning time, strengthen operational safety, and shorten the resumption of production time, online cleaning focuses on key areas, does not introduce other gases, and retains some strains.

[0049] like Figure 1As shown, the automatic cleaning system of the biological desulfurization tower of the present invention includes a desulfurization tower 1 and a circulation tank 2. The desulfurization tower 1 is a cylindrical structure; the bottom of the circulation tank 2 is conical, and the tank wall is cylindrical; a mud discharge pipe is provided at the conical bottom, and the side wall of the tank is connected to the bottom of the desulfurization tower 1 by a pipeline (divided into pumping and straight-through pipes), and multiple inlets and outlets such as liquid replenishment, deodorization, and filtration are provided on the side wall and the top of the tank. The lower part of the desulfurization tower 1 is connected to the air intake main pipe 3 with a control valve to realize the flow of biogas from bottom to top in the desulfurization tower 1. A spray head 17 is provided at the upper part of the desulfurization tower 1, and the spray head 17 is connected to the circulation tank 2 through a spray circulation pipe 19 with a control valve and a circulation pump 15 to realize the circulation liquid output from the circulation tank 2 to flow from top to bottom in the desulfurization tower 1. There are three layers of packing inside the desulfurization tower 1, and the spacing between single-layer packing is 1 to 3 meters. A connecting pipe with a cyclone aerator 4 is provided below the packing on the second layer, and a connecting pipe with a jet aerator 10 is provided below the packing on the bottom layer. A flow meter F is provided on the connecting pipe, and the connecting pipe includes a liquid inlet pipe and an air inlet pipe. The liquid inlet pipe is connected to the circulation tank 2 through a jet pump 13, and the air inlet pipe is connected to the circulation fan 18 to achieve separate cleaning of each layer of packing. Starting from the second layer of packing, a sewage outlet is provided at the tower wall 10 to 30 cm above each layer of packing. The sewage outlet is connected to a sewage outlet 8 with a control valve. The sewage outlet 8 is located below the first layer of packing and the second layer of packing, respectively. The sewage outlet 8 is connected to the circulation tank 2 to achieve direct discharge of the cleaning waste liquid in the desulfurization tower 1 into the circulation tank 2. Different aeration devices are provided at different packing layers to improve the cleaning quality of each layer of packing. In other embodiments, cyclone aeration can be replaced by microporous aeration, and jet aeration can be replaced by microporous aeration + high-pressure nozzle.

[0050] like Figure 1 As shown, the bottom of the bottom packing of the desulfurization tower 1 is connected to the lower part of the circulation tank 2 through a connecting pipe, and the connecting pipe includes two parallel branches, one of which is only provided with a control valve, and the other branch is provided with a connecting pump 12 and a control valve. The desulfurization tower 1 discharges the circulating liquid to the circulation tank 2 through the connecting pipe; the connecting pipe is provided with an air shield at the outlet of the desulfurization tower 1 to prevent the floating foam in the desulfurization tower 1 from entering the circulation tank 2.

[0051] like Figure 1 As shown, the outlet end of the circulation pump 15 is divided into two branches, one of which is connected to the desulfurization tower 1 through the spray circulation pipe 19, and the other branch returns to the circulation tank 2 through a pipeline with a control valve and a filter 9.

[0052] like Figure 1 As shown, the air intake pipe of the circulating fan 18 is connected to the bypass pipe 16 at the top of the desulfurization tower 1, and a coarse filter 6 and a fine filter 7 are provided on the air intake pipe of the circulating fan 18 in sequence. The coarse filter 6 is a gravel filter, and the fine filter 7 is a ceramic filter element filter. The gas discharged from the desulfurization tower 1 enters the circulating fan 18 after two-stage filtration.

[0053] like Figure 1 As shown, in the desulfurization tower 1, pressure sensors P and contact level switches L are provided between each layer of fillers. The contact level switch L is located above the sewage pipe 8; at the bottom of the desulfurization tower 1, the contact level switch L is located 5 to 10 cm above the bottom of the desulfurization tower 1. The pressure sensor P and oxygen detector O are provided on the transcending pipe 16 at the top of the desulfurization tower 1. Two high and low contact level switches L are provided in the circulation tank 2.

[0054] like Figure 1 As shown, the air intake main pipe 3 includes two branches, wherein the first branch is connected to the lower part of the desulfurization tower 1, and the second branch is connected to the air outlet pipe at the top of the desulfurization tower 1, and an air supply pipe 5 with a control valve is provided between the second branch and the upper part of the desulfurization tower 1, and the installation position of the air supply pipe 5 at the upper part of the desulfurization tower 1 is higher than the spray head 17.

[0055] In other embodiments, when there are only two layers of filler, the first layer of filler can be used as the second layer of filler to select the corresponding drain port and contact liquid level switch. When there is only one layer of filler, it is directly used as the bottom layer to configure the corresponding jet aerator, jet pump, drain port and contact liquid level switch.

[0056] During normal operation, the biogas flows from bottom to top through the packing layers in the desulfurization tower 1 and then flows out from the top of the tower. The circulating liquid is evenly sprayed from the spray head 17 at the top of the desulfurization tower 1, flows from top to bottom through the packing layers to the bottom of the tower, flows back to the circulation tank 2 through the bottom connecting pipe between the desulfurization tower 1 and the circulation tank 2, and then is pumped to the top of the desulfurization tower 1. The system starts the circulating liquid filtration every 1 to 12 hours. While ensuring the original circulation, the valve to the filter 9 is opened for 30 to 120 minutes to remove suspended matter in the circulating liquid.

[0057] This embodiment also provides a control method for the above-mentioned biological desulfurization tower automatic cleaning system, which automatically triggers the desulfurization tower 1 to perform overall cleaning or bottom packing layer cleaning through the overall pressure difference or layered pressure difference value in the desulfurization tower 1. When the pressure difference between the air inlet and the air outlet of the desulfurization tower 1 is 0.3-1.5 kPa and lasts for 12-72 hours, the overall cleaning is triggered. When the layered pressure difference between the adjacent two sides of the packing layer in the desulfurization tower 1 is 0.2-1 kPa and lasts for 6-48 hours, the bottom layer cleaning is triggered.

[0058] When the desulfurization tower 1 is cleaned as a whole, the following steps are included:

[0059] Step S1, open the control valve on the gas outlet pipe 20 at the top of the desulfurization tower 1, close the control valve on the gas inlet main pipe 3, and start the oxygen detector O;

[0060] Step S2, close the control valve on the connecting pipe between the bottom of the desulfurization tower 1 and the bottom of the circulation tank 2, keep the circulation pump 15 normally open, and close the filter bypass where the filter 9 is located;

[0061] Step S3, when the liquid level in the desulfurization tower 1 rises to trigger the contact liquid level switch L above the second layer of filler, the circulation pump 15 is turned off and the control valve on the outlet pipe 20 is closed;

[0062] Step S4, open the control valve on the air supply pipe 5, open the control valve on the connecting pipe connected to the cyclone aerator 4 below the second layer of filler, start the circulating fan 18, aerate and clean the second layer of filler, and control the aeration intensity at 0.5-1.5m 3 / m 2 ·min;

[0063] Step S5, after continuous aeration for 5 to 10 minutes, open and close the first drain valve from top to bottom on the side of the desulfurization tower 1 for 5 to 10 seconds; after continuing aeration for 5 to 30 minutes, close the control valve and the circulating fan 18 on the connecting pipe, open the second drain valve from top to bottom on the side of the desulfurization tower 1 to drain the liquid, and when the liquid level in the desulfurization tower 1 drops to the contact level switch L above the next layer of filler, close the second drain valve; after waiting for 5 to 30 minutes, start the drain pump 14 to discharge the sewage in the circulation tank 2 to the low liquid level;

[0064] Step S6, after the sewage pump 14 stops, the liquid level of the circulation tank 2 is automatically replenished, and the circulation pump 15 is started to replenish water to the desulfurization tower 1, and steps S3 to S6 are repeated 0 to 3 times;

[0065] Step S7, after completing the repeated steps, the liquid level in the desulfurization tower 1 is replenished to the position of the liquid level contact switch L above the bottom layer of filler, and the cleaning of the next layer of filler is started; when the next layer of filler is not the bottom layer, repeat steps S3 to S6, wherein the replenishing water level is correspondingly lowered to the position of the liquid level contact switch L above the cleaning layer filler, and the corresponding aeration connection control valve and the sewage valve are opened and closed; when the next layer of filler is the bottom layer, it is cleaned according to the following steps;

[0066] Step S8, start the jet pump 13, open the control valve connected to the jet aerator 10, start the circulation fan 18, and control the aeration intensity at 1-2 m / s by controlling the valve. 3 / m 2 ·min, the gas-water ratio is controlled at 4-4.5;

[0067] Step S9, after continuous aeration for 5 to 15 minutes, open and close the drain valve above the bottom filler for 10 to 30 seconds; continue aeration for 5 to 10 minutes, stop the jet pump 13 and the circulation fan 18, start the connecting pump 12 to discharge the sewage in the desulfurization tower 1 to the circulation tank 2, and when the liquid level reaches the contact liquid level switch L position at the bottom of the desulfurization tower 1, close the connecting pump 12;

[0068] Step S10: After the circulation tank 2 is left to stand for 10 to 30 minutes, the sewage pump 14 is started and stopped after the circulation tank 2 reaches the low liquid level; after the circulation tank 2 is replenished with water to the high liquid level, the circulation pump 15 is started to replenish the liquid level of the desulfurization tower 1 to the contact liquid level switch L above the bottom filler of the desulfurization tower 1; Steps S8 and S9 are repeated 1 to 3 times, wherein the aeration intensity is changed to 0.5 to 1.5 m 3 / m 2 ·min, the aeration time is changed to 10 to 30 minutes;

[0069] After step S11 is repeated, the control valve connected to the jet aerator 10 is opened, the jet pump 13, the circulation fan 18 and the connecting pump 12 are started, and the filtering circuit of the circulation pump 15 is turned on;

[0070] Step S12, after stopping aeration, open the drain valve on the first drain pipe 8 on the side of the desulfurization tower 1 from top to bottom for 5 to 10 seconds, keep the water supply valve of the circulation tank 2 normally closed, start the drain pump 14, and use the liquid level of the circulation tank 2 as the control point to open the drain valves of the drain pipes 8 on the side of the desulfurization tower 1 from top to bottom in sequence. When the drain valve of the second to last drain pipe 8 on the side of the desulfurization tower 1 from top to bottom is automatically closed, start the connecting pump 12 to discharge the circulating liquid of the desulfurization tower 1 into the circulation tank 2, and finally drain all the liquid in the circulation tank 2;

[0071] Step S13, after the whole machine is cleaned, the water supply valve of the circulation tank 2 is restored to the liquid level linkage; after the circulation tank 2 is replenished with liquid and bacteria, the circulation pump 15 is started to replenish the desulfurization tower 1 to the preset liquid level, the control valves on the air inlet main pipe 3 and the air outlet pipe 20 are started, and the control valve on the air supply pipe 5 is closed.

[0072] When the lower layer of the second filler layer is not the bottom layer, repeat steps S3 to S7 (the water replenishment level is correspondingly lowered to the position of the liquid level contact switch above the filler cleaning layer), and open and close the control valve and drain valve on the corresponding aeration pipe.

[0073] When the bottom layer of the desulfurization tower 1 is cleaned alone, the following steps are included:

[0074] Step Y1, open the control valve on the air outlet pipe 20 at the top of the desulfurization tower 1, close the control valve on the air inlet main pipe 3, and start the oxygen detector O.

[0075] Step Y2, close the control valve on the connecting pipe between the bottom of the desulfurization tower 1 and the bottom of the circulation tank 2, keep the circulation pump 15 normally open, and close the filter bypass where the filter 9 is located.

[0076] Step Y3: When the liquid level in the desulfurization tower 1 rises to trigger the liquid level contact switch L above the bottom filler, the circulation pump 15 is turned off and the control valve on the outlet pipe 20 is closed.

[0077] Step Y4, open the control valve on the air supply pipe 5, open the control valve on the aeration pipe connected to the jet aerator 10, start the jet pump 13 and the circulating fan 18, and control the aeration intensity at 1-2 m / s through the control valve. 3 / m 2 ·min, the gas-water ratio is controlled at 4-4.5.

[0078] Step Y5, after continuous aeration for 5 to 15 minutes, open the control valve of the sewage pipe 8 above the bottom filler for 10 to 30 seconds; continue aeration for 5 to 10 minutes, turn off the jet pump 13 and the circulating fan 18, start the connecting pump 12 to drain water to the circulation tank 2, and turn off the connecting pump 12 after the liquid level reaches the liquid level contact switch L at the bottom of the desulfurization tower 1 that triggers it.

[0079] Step Y6, start the sewage pump 14 to discharge the circulating tank 2 to the low liquid level and then stop; after the circulating tank 2 is replenished with water to the high liquid level, start the circulating pump 15 to replenish the liquid level of the desulfurization tower 1 to the liquid level contact switch L at the bottom of the desulfurization tower 1; repeat steps Y4 and Y5 1 to 3 times, wherein the aeration intensity is changed to 0.5 to 1.5 m 3 / m 2 ·min, the aeration time is changed to 10 to 30 minutes.

[0080] Step Y7, after the circulation tank 2 is replenished with liquid and bacteria, the circulation pump 15 is started to replenish liquid to the desulfurization tower 1 (close the filter valve) to the preset liquid level, the control valves on the air inlet main pipe 3 and the air outlet pipe 20 are opened, and the control valve on the air replenishment pipe 5 is closed.

[0081] Whether in the overall cleaning or layered cleaning process, the oxygen detector O continuously monitors the circulating biogas in the desulfurization tower 1. When the oxygen concentration is higher than 2.5%, an alarm is issued, and when the oxygen concentration is higher than 3%, the cleaning is automatically stopped.

[0082] In this embodiment, the suspended solids can be removed during operation, and the packing can be cleaned in layers and the scale on the tank wall can be flushed without opening the tower for unloading. No air or other inert substances are introduced into the cleaning process, and no gas replacement is required before and after cleaning, and the amount of odor generated during the process is extremely small.

[0083] Example 2

[0084] In a φ3000 bio-acid desulfurization tower system, the tower packing is divided into three layers, each layer is 2 meters apart. Four cyclone aerators 4 are arranged below the second layer of packing, arranged at the 1 / 4 and 3 / 4 positions of two vertical diameters, arranged in a square, and share an aeration mother pipe. A ten-way jet aerator 10 is arranged in the center below the third layer of packing. A sewage pipe 8 is arranged 15 cm above the second and third layers of packing, and a liquid level contact switch L is set 5 cm above the sewage pipe 8.

[0085] During normal operation, the system starts the circulating liquid filtration every 8 hours. While ensuring the original circulation, the valve to the filter 9 is opened for 60 minutes to remove suspended matter in the circulating liquid.

[0086] During operation, the overall pressure difference is set to 0.8kPa and the duration is 48h to trigger overall cleaning. The stratified pressure difference is set to 0.3kPa and the duration is 24h to trigger bottom layer cleaning.

[0087] The aeration intensity of the second layer of filler is set to 0.5~0.7m 3 / m 2 ·min, after 8 minutes of continuous aeration, open the drain valve for 20 seconds. After 15 minutes of continuous aeration, the drain waiting time of circulation tank 2 is set to 10 minutes. The number of single repetitions is 0.

[0088] The aeration intensity of the bottom layer of filler for cleaning is set to 1~1.2m 3 / m 2 ·min, the air-water ratio is controlled at 4. After 8 minutes of continuous aeration, open the drain valve for 15 seconds and continue aeration for 10 minutes. The circulation tank drain is left to stand for 15 minutes. The number of repetitions is 1, and the aeration intensity is 0.5-1m 3 / m 2 ·min, aeration time is 30 minutes.

[0089] Since the effect can be achieved by cleaning a single layer alone, the system does not have a separate setting for cleaning the entire filler after the bottom layer cleaning is completed.

[0090] Example 3

[0091] In a φ2200 bio-acid desulfurization tower system, the tower packing is divided into two layers, each layer is 1.5 meters apart. Only a six-way jet aerator 10 is arranged at the center below the bottom packing. A sewage pipe 8 is arranged 20 cm above the bottom packing, and a liquid level contact switch L is set 10 cm above the sewage pipe 8. A liquid level contact switch L is arranged 20 cm above the first layer of packing.

[0092] During normal operation, the system starts the circulating liquid filtration every 8 hours. While ensuring the original circulation, the valve to the filter 9 is opened for 120 minutes to remove suspended matter in the circulating liquid.

[0093] During operation, the overall pressure difference is set to 1kPa and the duration is 48h to trigger overall cleaning, and the stratified pressure difference is set to 0.7kPa and the duration is 24h to trigger bottom layer cleaning.

[0094] The aeration intensity of the bottom filler cleaning is set to 1.5~1.8m 3 / m 2·min, the air-water ratio is controlled at 4. After 13 minutes of continuous aeration, open the drain valve for 30 seconds and continue aeration for 10 minutes. The circulation tank drain is left to stand for 20 minutes. The number of single repetitions is 2, and the aeration intensity is 0.8~1.2m 3 / m 2 ·min, aeration time is 30 minutes.

[0095] After repeated cleaning, the liquid level is replenished to the contact level switch above the first layer of filler, and the aeration intensity of the bottom layer is controlled at 1-1.2m 3 / m 2 ·min, continuous aeration for 30 minutes. After stopping all water pumps and fans, the valve of the sewage pipe on the top floor of the tower is opened for 10 seconds and then closed.

[0096] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A biological desulfurization tower automatic cleaning system, characterized in that: The invention comprises a desulfurization tower (1) and a circulation tank (2), wherein the lower part of the desulfurization tower (1) is connected to an air intake main pipe (3) with a control valve so as to enable the biogas to flow from bottom to top in the desulfurization tower (1); a spray head (17) is provided at the upper part of the desulfurization tower (1), and the spray head (17) is connected to the circulation tank (2) through a spray circulation pipe (19) with a control valve and a circulation pump (15) so as to enable the circulating liquid outputted from the circulation tank (2) to flow from top to bottom in the desulfurization tower (1); and multiple layers of fillers are provided inside the desulfurization tower (1), and the fillers located in the middle layers are A connecting pipe with a cyclone aerator (4) is provided below, and a connecting pipe with a jet aerator (10) is provided below the bottom layer of filler, the connecting pipe comprising a liquid inlet pipe and an air inlet pipe, the liquid inlet pipe is connected to the circulation tank (2) via a jet pump (13), and the air inlet pipe is connected to a circulation fan (18) to achieve separate cleaning of each layer of filler; a plurality of sewage pipes (8) with control valves are provided on the side of the desulfurization tower (1), and the sewage pipes (8) are connected to the circulation tank (2) to achieve direct discharge of cleaning waste liquid in the desulfurization tower (1) into the circulation tank (2).

2. The automatic cleaning system for the biological desulfurization tower according to claim 1 is characterized in that: The desulfurization tower (1) is connected to a circulation tank (2) via a connecting pipe, wherein the connecting pipe comprises two parallel branches, one of which is provided with a control valve, and the other is provided with a connecting pump (12) and a control valve; the desulfurization tower (1) discharges circulating liquid to the circulation tank (2) via the connecting pipe; and an air shield (11) is provided at the inlet of the connecting pipe located in the desulfurization tower (1).

3. The automatic cleaning system for the biological desulfurization tower according to claim 2 is characterized in that: The outlet end of the circulation pump (15) is divided into two branches, one of which is connected to the desulfurization tower (1) through a spray circulation pipe (19), and the other branch returns to the circulation tank (2) through a pipeline with a control valve and a filter (9).

4. The automatic cleaning system for the biological desulfurization tower according to claim 3 is characterized in that: The air inlet pipe of the circulation fan (18) is connected to the air outlet pipe (20) at the top of the desulfurization tower (1), and a coarse filter (6) and a fine filter (7) are sequentially arranged on the air inlet pipe of the circulation fan (18). The gas discharged from the desulfurization tower (1) enters the circulation fan (18) after two-stage filtration.

5. The automatic cleaning system for a biological desulfurization tower according to any one of claims 1 to 4, characterized in that: In the desulfurization tower (1), pressure sensors P and contact liquid level switches L are provided between each layer of filler, and the contact liquid level switch L is located above the sewage discharge pipe (8); the pressure sensor P and oxygen detector O are provided on the gas outlet pipe (20) at the top of the desulfurization tower (1).

6. The automatic cleaning system for a biological desulfurization tower according to any one of claims 1 to 4, characterized in that: The air intake main pipe (3) comprises two branches, wherein the first branch is connected to the lower part of the desulfurization tower (1), and the second branch is connected to the bypass pipe (16) on the side of the desulfurization tower (1), and the upper part of the bypass pipe (16) is provided with an air supply pipe (5) with a control valve, and the installation position of the air supply pipe (5) on the upper part of the desulfurization tower (1) is higher than the spray head (17).

7. A control method for the automatic cleaning system of a biological desulfurization tower according to any one of claims 1 to 6, characterized in that: The desulfurization tower (1) is automatically triggered to perform overall cleaning or bottom packing layer cleaning through the overall pressure difference or layered pressure difference value in the desulfurization tower (1); when the pressure difference between the air inlet and the air outlet of the desulfurization tower (1) is between 0.3 and 1.5 kPa and lasts for 12 to 72 hours, the overall cleaning is triggered; when the layered pressure difference between the adjacent two packing layers in the desulfurization tower (1) is between 0.2 and 1 kPa and lasts for 6 to 48 hours, the bottom layer cleaning is triggered.

8. The control method according to claim 7, characterized in that: When the desulfurization tower (1) is cleaned as a whole, the following steps are included: Step S1, open the control valve on the outlet pipe (20) at the top of the desulfurization tower (1), close the control valve on the intake manifold (3), and start the oxygen detector O; Step S2, closing the control valve on the connecting pipe between the bottom of the desulfurization tower (1) and the bottom of the circulation tank (2), keeping the circulation pump (15) normally open, and closing the filter bypass where the filter (9) is located; Step S3, when the liquid level in the desulfurization tower (1) rises to trigger the contact liquid level switch L above the second layer of filler, the circulation pump (15) is turned off and the control valve on the outlet pipe (20) is closed; Step S4, open the control valve on the air supply pipe (5), open the control valve on the connecting pipe below the second layer of filler connected to the cyclone aerator (4), start the circulating fan (18), aerate and clean the second layer of filler, and control the aeration intensity at 0.5 to 1.5 m / s by controlling the valve. 3 / m 2 ·min; Step S5, after continuous aeration for 5 to 10 minutes, open and close the first drain valve from top to bottom on the side of the desulfurization tower (1) for 5 to 10 seconds; after continuing aeration for 5 to 30 minutes, close the control valve and the circulation fan (18) on the connecting pipe, open the second drain valve from top to bottom on the side of the desulfurization tower (1) to drain liquid, and when the liquid level in the desulfurization tower (1) drops to the contact liquid level switch L above the next layer of filler, close the second drain valve; after waiting for 5 to 30 minutes, start the drain pump (14) to discharge the sewage in the circulation tank (2) to the low liquid level; Step S6, after the sewage pump (14) stops, the liquid level of the circulation tank (2) is automatically replenished, and the circulation pump (15) is started to replenish water to the desulfurization tower (1), and steps S3 to S6 are repeated 0 to 3 times; Step S7, after completing the repeated steps, the liquid level in the desulfurization tower (1) is replenished to the position of the liquid level contact switch L above the bottom layer of filler, and the cleaning of the next layer of filler is started; when the next layer of filler is not the bottom layer, steps S3 to S6 are repeated, wherein the replenishing liquid level is correspondingly lowered to the position of the liquid level contact switch L above the cleaning layer filler, and the corresponding aeration connection control valve and the sewage valve are opened and closed; when the next layer of filler is the bottom layer, cleaning is performed according to the following steps; Step S8, start the jet pump (13), open the control valve connected to the jet aerator (10), start the circulation fan (18), and control the aeration intensity at 1-2 m / s by controlling the valve. 3 / m 2 ·min, the gas-water ratio is controlled at 4-4.5; Step S9: After continuous aeration for 5 to 15 minutes, open and close the drain valve above the bottom filler for 10 to 30 seconds; continue aeration for 5 to 10 minutes, stop the jet pump (13) and the circulation fan (18), start the connecting pump (12) to discharge the sewage in the desulfurization tower (1) into the circulation tank (2), and when the liquid level reaches the contact liquid level switch L position at the bottom of the desulfurization tower (1), close the connecting pump (12); Step S10: After the circulation tank (2) is left to stand for 10 to 30 minutes, the sewage pump (14) is started and stopped when the circulation tank (2) reaches a low liquid level; after the circulation tank (2) is replenished with water to a high liquid level, the circulation pump (15) is started to replenish the liquid level of the desulfurization tower (1) to the contact liquid level switch L above the bottom filler of the desulfurization tower (1); Steps S8 and S9 are repeated 1 to 3 times, wherein the aeration intensity is changed to 0.5 to 1.5 m 3 / m 2 ·min, the aeration time is changed to 10 to 30 minutes; After step S11 is repeated, the control valve connected to the jet aerator (10) is opened, the jet pump (13), the circulation fan (18) and the connecting pump (12) are started, and the filtration circuit of the circulation pump (15) is opened; Step S12, after stopping aeration, open the sewage valve on the first sewage pipe (8) from top to bottom on the side of the desulfurization tower (1) for 5 to 10 seconds, keep the water supply valve of the circulation tank (2) normally closed, start the sewage pump (14), and use the liquid level of the circulation tank (2) as the control point to open the sewage valves of the sewage pipes (8) on the side of the desulfurization tower (1) from top to bottom in sequence. When the sewage valve of the second to last sewage pipe (8) on the side of the desulfurization tower (1) from top to bottom is automatically closed, start the connecting pump (12) to discharge the circulating liquid of the desulfurization tower (1) into the circulation tank (2), and finally drain all the liquid in the circulation tank (2); Step S13, after the whole machine is cleaned, the water supply valve of the circulation tank (2) is restored to the liquid level linkage; after the circulation tank (2) is replenished with liquid and bacteria, the circulation pump (15) is started to replenish the desulfurization tower (1) with liquid to a preset liquid level, the control valves on the air inlet main pipe (3) and the air outlet pipe (20) are started, and the control valve on the air supply pipe (5) is closed.

9. The control method according to claim 7, characterized in that: When the bottom layer of the desulfurization tower (1) is cleaned alone, the following steps are included: Step Y1, open the control valve on the outlet pipe (20) at the top of the desulfurization tower (1), close the control valve on the intake manifold (3), and start the oxygen detector O; Step Y2, close the control valve on the connecting pipe between the bottom of the desulfurization tower (1) and the bottom of the circulation tank (2), keep the circulation pump (15) normally open, and close the filter bypass where the filter (9) is located; Step Y3, when the liquid level in the desulfurization tower (1) rises to trigger the liquid level contact switch L above the bottom packing, the circulation pump (15) is turned off and the control valve on the outlet pipe (20) is closed; Step Y4: Open the control valve on the air supply pipe (5), open the control valve on the aeration pipe connected to the jet aerator (10), start the jet pump (13) and the circulation fan (18), and control the aeration intensity at 1 to 2 m / s through the control valve. 3 / m 2 ·min, the gas-water ratio is controlled at 4-4.5; Step Y5: After continuous aeration for 5 to 15 minutes, open the control valve of the drainage pipe (8) above the bottom filler for 10 to 30 seconds; continue aeration for 5 to 10 minutes, turn off the jet pump (13) and the circulation fan (18), start the connecting pump (12) to drain water to the circulation tank (2), and turn off the connecting pump (12) after the liquid level reaches the level contact switch L at the bottom of the desulfurization tower (1); Step Y6, start the sewage pump (14) to discharge the sewage from the circulation tank (2) to the low liquid level and then stop; after the circulation tank (2) is replenished with water to the high liquid level, start the circulation pump (15) to replenish the liquid level of the desulfurization tower (1) to the liquid level contact switch L at the bottom of the desulfurization tower (1); repeat steps Y4 and Y5 1 to 3 times, wherein the aeration intensity is changed to 0.5 to 1.5 m 3 / m 2 ·min, the aeration time is changed to 10 to 30 minutes; Step Y7, after the circulation tank (2) is replenished with liquid and bacteria, the circulation pump (15) is started to replenish the desulfurization tower (1) with liquid to a preset liquid level, the control valves on the air inlet main pipe (3) and the air outlet pipe (20) are opened, and the control valve on the air replenishment pipe (5) is closed.

10. The control method according to claim 8 or 9, characterized in that: During the cleaning process, the oxygen detector O continuously monitors the circulating biogas in the desulfurization tower (1). When the oxygen concentration is higher than 2.5%, an alarm is sounded, and when the oxygen concentration is higher than 3%, the cleaning is automatically stopped.

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