A dry and wet flue gas desulfurization treatment device and method
Through the dry and wet flue gas desulfurization treatment device, combined with dry and wet filler layers and grinding dryers, the problems of complex equipment, high energy consumption and high cost in traditional desulfurization technology are solved, and more efficient and economical smoke is achieved. Gas desulfurization effect.
Patent Information
- Application Number
- CN202010275690.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2020-04-09
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2040-04-09
AI Technical Summary
Traditional flue gas desulfurization technology has problems such as complex equipment, high energy consumption, high cost and excessive footprint. In particular, dry and semi-dry desulfurization technology requires large desulfurization reactors and dust removal equipment, resulting in large overall device size. , high cost.
Using dry and wet flue gas desulfurization treatment device, combined with dry and wet filler layers, intermittent spraying and desulfurization agent regeneration is achieved through spray pipes and grinding dryers, reducing the use of cyclone separators and bag dust collectors, and improving the use of Resource utilization and desulfurization efficiency.
The desulfurization equipment has been achieved smaller volume, reduced energy consumption and cost, improved resource utilization and desulfurization efficiency, avoided the occurrence of "white smoke" phenomenon, and met environmental protection emission standards.
Smart Images
Figure CN111318143B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of flue gas desulfurization environmental protection, and in particular to a dry and wet flue gas desulfurization treatment device and method. Background Art
[0002] At present, the flue gas desulfurization technologies mainly include wet, dry and semi-dry desulfurization technologies.
[0003] Wet desulfurization technology: mainly uses desulfurizer solution to spray in the reaction tower to form water mist to contact and react with sulfur dioxide in the flue gas, and the generated reactants are discharged after precipitation. The desulfurizer solution can be circulated multiple times, and new desulfurizer and water are continuously added. Its disadvantages are that the device is large in size, and there are problems with sewage and waste acid treatment, and the energy consumption is high. In particular, the flue gas temperature is reduced after purification, which is not conducive to the diffusion of chimney exhaust. At the same time, the "white smoke" phenomenon (water mist) will be generated. The purified flue gas needs to be heated again, otherwise the low-temperature flue gas is corrosive and will cause corrosion to the chimney.
[0004] Dry desulfurization technology: adopts the integrated design of quicklime (CaO) digestion and ash circulation humidification to ensure freshly digested high-quality slaked lime (Ca(OH) 2 ) is immediately put into the circulating desulfurization reaction; the circulating ash is used to carry moisture to form a water film on the surface of the dust particles. The thin layer of water film on the surface of the dust particles evaporates in the flue gas flow in an instant, forming an ideal reaction environment with suitable temperature and humidity in a very short time. Since the time to establish an ideal reaction environment is reduced, it is possible to greatly reduce the total reaction time, which can effectively reduce the height of the desulfurization reactor; the circulating ash is collected by a cyclone separator and a bag dust collector. The collected powder is recycled and reused on the one hand, and discharged as the final reactant on the other.
[0005] Semi-dry desulfurization technology: the desulfurizer powder is slurried with water and then sprayed into the reactor. In the reactor, the droplets formed by the desulfurizer slurry mix with sulfur dioxide to react. At the same time, the desulfurizer slurry is heated by the flue gas and the water evaporates to form a powder which is collected by a cyclone separator and a bag dust collector. The collected powder is recycled to make slurry for repeated use and discharged as the final reactant.
[0006] The disadvantages of dry and semi-dry desulfurization technology are: the desulfurization reactor still needs a certain volume of space to ensure that the flue gas stays in the reactor for a long enough time. At the same time, a cyclone separator and a bag dust collector must be added after the reactor to collect powder. The volume of the cyclone separator and the bag dust collector will become larger and larger as the flue gas flow rate increases, causing the entire desulfurization treatment device to occupy too much space and the cost to increase. Summary of the invention
[0007] In view of the above problems, the present invention studies and designs a dry and wet flue gas desulfurization treatment device and method to solve the shortcomings of the traditional flue gas desulfurization process, such as complex desulfurization equipment, high energy consumption and high cost. The technical means adopted by the present invention are as follows:
[0008] A dry and wet flue gas desulfurization treatment device, comprising a desulfurization tower, an air inlet pipeline, an air outlet pipeline, a first delivery pump, a second delivery pump, a desulfurizer storage tank and a waste tank;
[0009] The desulfurization tower is provided with a flue gas inlet at the top and a sewage outlet at the bottom, the flue gas inlet is connected to the air inlet pipe, the sewage outlet is connected to the inlet of the first delivery pump, the outlet of the first delivery pump is connected to the waste tank through a pipeline, the desulfurization tower is provided with a dry packing layer, a spray pipe and a wet packing layer in sequence from the top to the bottom, a flue gas outlet is provided on the wall of the desulfurization tower between the wet packing layer and the sewage outlet, the flue gas outlet is connected to the air outlet pipe, and the desulfurization tower is provided with an external water supply pipe;
[0010] The inlet of the second delivery pump is connected to the bottom of the desulfurization tower through a pipeline, and the outlet of the second delivery pump is connected to the spray pipe through a pipeline;
[0011] The outlet of the desulfurizing agent storage tank is provided with a third delivery pump, and the third delivery pump is connected to the air intake pipeline through a desulfurizing agent input pipe.
[0012] Preferably, a grinding dryer is provided on the pipeline between the first delivery pump and the waste tank, the grinding dryer includes a stirring bin and a powder silo, the bottom of the stirring bin is provided with a discharge port, the discharge port is connected to the powder silo, the stirring bin is provided with a sediment inlet and a water vapor outlet, the sediment inlet is connected to the outlet of the first delivery pump through a pipeline, the outlet of the powder silo is provided with a fourth delivery pump, the fourth delivery pump is connected to the waste tank through a waste discharge pipe, the waste discharge pipe is provided with a first control valve, the waste discharge pipe between the first control valve and the fourth delivery pump is provided with a desulfurizer regeneration pipe, one end of the desulfurizer regeneration pipe is communicated with the waste discharge pipe, and the other end is connected to the air intake pipe, and the desulfurizer regeneration pipe is provided with a second control valve.
[0013] Preferably, the stirring chamber comprises a shell, an agitator, an agitator shaft, a driving device and a bracket, one side of the shell is attached to the outer wall of the desulfurization tower and is fixedly connected to the outer wall of the desulfurization tower, the agitator is connected to the agitator shaft, the agitator shaft is connected to the driving device, and the agitator shaft is fixed in the shell through the bracket;
[0014] The discharge port is provided with a rubber sealing gasket for covering the surrounding shell of the discharge port, and the discharge side of the discharge port is provided with a discharge gate, a gate base and a cylinder, the discharge gate is fitted to the rubber sealing gasket, the gate base is provided with a guide rail matching with the discharge gate, the cylinder drives the discharge gate to slide on the guide rail, and the discharge gate is provided with a powder discharge trough matching with the discharge port.
[0015] Preferably, a blower is further included, the air outlet duct of the blower is respectively connected to the desulfurizer input pipe and the desulfurizer regeneration pipe, the water vapor outlet is connected to the condenser, and the outlet of the condenser extends into the bottom of the desulfurization tower.
[0016] Preferably, grinding balls are arranged in the shell, and the grinding balls are stainless steel balls or ceramic balls. A temperature transmitter is arranged on the shell, and a spring sheet for supporting the discharge gate is arranged on the gate base.
[0017] Preferably, the desulfurization tower is provided with a differential pressure transmitter for detecting the pressure difference between the air inlet side and the air outlet side of the wet packing layer, the bottom of the desulfurization tower is provided with a liquid level transmitter, and the air outlet pipe is provided with a flue gas analyzer.
[0018] Preferably, the smoke outlet is provided with a demister, the demister is connected to the gas outlet duct, and the fillers in the dry filler layer and the wet filler layer are stainless steel balls for washing, stainless steel wire mesh corrugated fillers or stainless steel calendered punctured corrugated fillers.
[0019] Preferably, the system further comprises a controller, wherein the controller is connected to the control system.
[0020] A dry-wet flue gas desulfurization treatment method based on the dry-wet flue gas desulfurization treatment device comprises the following steps:
[0021] S1. Add circulating water into the desulfurization tower through the external water supply pipe, start the second delivery pump, deliver the circulating water at the bottom of the desulfurization tower to the spray pipe, and spray the wet packing layer;
[0022] S2, introduce sulfur-containing flue gas into the desulfurization tower, and start the third delivery pump and blower to deliver the new desulfurizer powder to the air intake pipe to mix with the sulfur-containing flue gas. After the mixed gas enters the desulfurization tower, it passes through the dry packing layer and the wet packing layer in sequence, and then is discharged to the outside of the desulfurization tower through the demister;
[0023] S3. When a reactant precipitation layer is formed at the bottom of the desulfurization tower, the first delivery pump is started to discharge the bottom precipitation into the waste tank. When the circulating water volume at the bottom of the desulfurization tower is lower than a certain liquid volume, water is added to the desulfurization tower through an external water supply pipe;
[0024] S4. Repeat steps S1-S3 to complete the continuous desulfurization process of the sulfur-containing flue gas.
[0025] Preferably, in step S3, when a reactant precipitation layer is formed at the bottom of the desulfurization tower, the first delivery pump is started to discharge the bottom precipitate into the grinding and drying device for grinding and drying. After grinding and drying into powder, the second control valve is opened, the first control valve is closed, and the fourth delivery pump and the blower are started to transport the powder to the air intake pipe through the desulfurizer regeneration pipe, and the powder is mixed with the sulfur-containing flue gas and then enters the desulfurization tower; when it is detected that the desulfurizer content in the bottom precipitate layer is lower than a certain proportion, the second control valve is closed, the first control valve is opened, and the final reaction waste is discharged into the waste tank.
[0026] Compared with the prior art, the dry and wet flue gas desulfurization treatment device and method described in the present invention have the following beneficial effects:
[0027] 1. The present invention adopts a desulfurization device and method that combines dry and wet methods. Compared with the traditional desulfurization process, it does not require a cyclone separator, a bag dust collector, and a post-stage centrifugal fan. The desulfurization equipment is smaller in size and more integrated, reducing energy consumption and costs.
[0028] 2. The grinding dryer in the present invention can recycle the desulfurizer powder and circulating water, thereby improving resource utilization; the wet filler layer can not only allow the sulfur dioxide in the flue gas to react quickly with the wet desulfurizer powder, but also adsorb and filter the desulfurizer powder and particulate matter in the flue gas, thereby ensuring the desulfurization efficiency.
[0029] 3. The present invention adopts an intermittent spraying method. At the same time, the bottom sediment formed by the combination of moisture in the wet packing layer and powder in the flue gas is dried by a grinding dryer and then reused after condensation, saving water. In addition, the flue gas after desulfurization carries less moisture, and a demister is set at the flue gas outlet to prevent the exhaust flue gas from producing a "white smoke" phenomenon. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 It is a schematic diagram of the overall flow of the device in an embodiment of the present invention.
[0031] Figure 2 Schematic diagram of the top view of the spray pipe in the embodiment of the present invention.
[0032] Figure 3 1 is a schematic diagram of the top view of the grinding and drying device in an embodiment of the present invention.
[0033] Figure 4 Schematic diagram of the structure of the condenser in the embodiment of the present invention.
[0034] Figure 5 It is a schematic diagram of the main structure of the discharge port of the grinding and drying device in an embodiment of the present invention.
[0035] Figure 6It is a schematic diagram of the top view of the discharge port of the grinding and drying device in an embodiment of the present invention.
[0036] Figure 7 Schematic diagram of the top view of the gate base in the embodiment of the present invention.
[0037] In the figure, 1, desulfurization tower; 2, grinding dryer; 3, air inlet pipe; 4, air outlet pipe; 5, first delivery pump; 6, second delivery pump; 7, desulfurization agent storage tank; 8, waste tank; 9, blower; 10, control system; 11, flue gas inlet; 12, flue gas outlet; 13, sewage outlet; 14, dry packing layer; 15, spray pipe; 16, wet packing layer; 17, demister; 21, mixing bin; 22, powder bin; 23, discharge port; 24, shell; 25, outer cover; 31, external water supply pipe; 71, third delivery pump; 72, desulfurization agent input pipe; 91, air outlet pipe; 101, control panel; 102, differential pressure transmitter; 103, liquid level transmitter; 104. Temperature transmitter; 105. Flue gas analyzer; 106. Second control valve; 107. First control valve; 151. Main pipe; 152. Branch pipe; 153. Sprinkler head; 211. Sediment inlet; 212. Water vapor outlet; 213. Condenser; 214. Grinding ball; 215. Agitator; 216. Driving device; 217. Bracket; 218. Agitator shaft; 221. Fourth delivery pump; 222. Waste discharge pipe; 223. Desulfurizer regeneration pipe; 231. Rubber sealing pad; 232. Discharge gate; 233. Gate base; 234. Cylinder; 235. Powder discharge trough; 236. Spring sheet; 251. Heat sink; 252. Heat dissipation hole. DETAILED DESCRIPTION
[0038] The present invention is further described in detail below in conjunction with embodiments and drawings.
[0039] like Figure 1-7 As shown, a dry-wet flue gas desulfurization treatment device includes a desulfurization tower 1, a grinding dryer 2, an air inlet pipe 3, an air outlet pipe 4, a first delivery pump 5, a second delivery pump 6, a desulfurizer storage tank 7, a waste tank 8, a blower 9 and a control system 10. In this embodiment, the control system 10 uses a PLC control system and is controlled and operated through a control panel 101; the first delivery pump 5 uses a sludge pump or the like that can be used to transport solid-liquid mixtures, and the second delivery pump 6 uses a circulating water pump or the like that can be used to transport circulating water. The first delivery pump 5 and the second delivery pump 6 are both connected to the control system 10 and can be controlled by the control system 10.
[0040] The top of the desulfurization tower 1 is provided with a flue gas inlet 11, and the bottom of the tower is provided with a sewage outlet 13. The flue gas inlet 11 is connected to the air intake pipe 3, and the sewage outlet 13 is connected to the inlet of the first delivery pump 5. The outlet of the first delivery pump 5 is connected to the grinding dryer 2 through a pipeline, and the grinding dryer 2 is connected to the waste tank 8 through the waste discharge pipe 222. The desulfurization tower 1 is provided with a dry packing layer 14, a spray pipe 15 and a wet packing layer 16 from the top to the bottom of the tower, and the desulfurization tower 1 is provided with an external water supply pipe 31 for replenishing circulating water. A flue gas outlet 12 is provided on the tower wall of the desulfurization tower 1 between the wet packing layer 16 and the sewage outlet 13, and a demister 17 is provided at the flue gas outlet 12, and the demister 17 is connected to the gas outlet pipe 4. The desulfurization tower 1 is provided with an external water supply pipe 31, and circulating water can be replenished into the desulfurization tower 1 through the external water supply pipe 31 to form a clear water layer at the bottom of the tower.
[0041] The reaction between sulfur dioxide in sulfur-containing flue gas and desulfurizer is mainly completed in the dry packing layer 14 and the wet packing layer 16, and the desulfurizer powder carried in the flue gas is filtered through the wet packing layer 16. The packing in the dry packing layer 14 and the wet packing layer 16 can be composed of stainless steel balls for washing, or stainless steel wire mesh corrugated packing or stainless steel calendered punctured corrugated packing or granular packing, or packing with high specific surface area and forming small, complex and staggered interspace passages.
[0042] The dry packing layer 14 serves as the main desulfurization reaction zone. Due to the high specific surface area and small, complex and interlaced void channels formed by the packing, the flue gas and the desulfurizer powder collide and flow with each other on the outer walls and void channels of these packings, prompting the sulfur dioxide in the flue gas to fully contact and react with the desulfurizer powder quickly, effectively shortening the reaction time and improving the desulfurization effect.
[0043] like Figure 2As shown, the spray pipe 15 is fixed at the middle and upper part of the desulfurization tower 1. The spray pipe 15 consists of a main pipe 151 and branches 152 connected to the main pipe 151. A plurality of spray heads 153 are installed on the branch pipes 152. The spray heads 153 are evenly distributed according to the circular cross-section of the desulfurization tower 1, so that the water mist sprayed by the spray heads 153 can evenly cover the entire wet packing layer 16. The spray pipe 15 is connected to the outlet of the second delivery pump 6 through a pipeline. The inlet pipeline of the second delivery pump 6 is connected to the bottom of the desulfurization tower 1 and immersed in the clear water layer at the bottom of the tower. The second delivery pump 6 pumps the clean water of the clear water layer at the bottom of the desulfurization tower 1 into the spray pipe 15, and the wet packing layer 16 is sprayed and moistened by the spray heads. Since part of the desulfurizer powder in the sulfur-containing flue gas will dissolve into the water when passing through the wet packing layer 16, the clean water at the bottom of the desulfurization tower 1 also contains desulfurizer dissolved substances, and this part of the desulfurizer can be transported to the upper part of the desulfurization tower 1 through the second delivery pump 6 for recycling, thereby reducing costs. The second delivery pump 6 is connected to the PLC control system, and the PLC control system controls the spraying amount of the spray pipe 15 by controlling the second delivery pump 6. In this embodiment, the PLC control system controls the spray pipe 15 to perform intermittent spraying, which not only ensures the normal wetting of the wet packing layer 16, but also reduces the evaporation of circulating water in the desulfurization tower 1, saving water.
[0044] The desulfurization tower 1 is provided with a differential pressure transmitter 102 for detecting the pressure difference between the air inlet side and the air outlet side of the wet packing layer 16, and the differential pressure transmitter 102 is connected to the PLC control system. When the desulfurizer powder and fly ash in the sulfur-containing flue gas continue to pass through the wet packing layer 16, part of the desulfurizer powder and fly ash will be deposited in the wet packing layer 16, blocking the gap inside the wet packing layer 16, thereby affecting the desulfurization efficiency and desulfurization effect of the desulfurization tower 1. At this time, the pressure difference between the two end surfaces of the wet packing layer 16 can be monitored by the differential pressure transmitter 102, and the blockage of the wet packing layer 16 can be judged according to the change in the pressure difference. When it is judged that there are too many impurities deposited in the wet packing layer 16, the second delivery pump 6 is controlled by the PLC control system to spray a large flow of water in a short time to flush the wet packing layer 16, so that the adhering desulfurizer powder and fly ash are washed to the bottom of the desulfurization tower 1 and precipitated to form a tower bottom sedimentation layer. A fixed flushing time period may also be set, and the spraying amount may be increased at regular intervals to clean the wet packing layer 16 to ensure a stable desulfurization effect.
[0045] A liquid level transmitter 103 is provided at the bottom of the desulfurization tower 1, and the liquid level transmitter 103 is connected to the PLC control system. Since the circulating water in the desulfurization tower 1 will be discharged with the flue gas in the form of water vapor, the water volume will gradually decrease. When the liquid level transmitter 103 detects that the water volume in the desulfurization tower 1 is insufficient (that is, the liquid level of the clear water layer at the bottom of the tower is too low, and the inlet pipeline of the second delivery pump 6 cannot take water from the desulfurization tower 1), water is added to the desulfurization tower 1 through the external water supply pipe 31.
[0046] The spray pipe 15 and the wet packing layer 16 serve as auxiliary desulfurization reaction areas and main dust filtering areas, which can not only allow the sulfur dioxide in the flue gas to react quickly with the wet desulfurizer powder, but also adsorb and filter the desulfurizer powder and particulate matter in the flue gas. After passing through the dry packing layer 14 and the wet packing layer 16, most of the sulfur dioxide in the flue gas is removed, and the wet packing layer 16 also filters out the dust in the flue gas. The clean flue gas that meets the environmental emission standards after desulfurization and deashing is defogged by the demister 17 and discharged through the outlet pipe 4.
[0047] The outlet of the desulfurizing agent storage tank 7 is provided with a third delivery pump 71 (in this embodiment, a screw metering pump is used), and the third delivery pump 71 is connected to the air intake pipe 3 through the desulfurizing agent input pipe 72. The third delivery pump 71 is connected to the PLC control system, and the real-time addition amount of the desulfurizing agent can be controlled by the PLC control system to ensure a good desulfurization effect. The air outlet pipe 91 of the blower 9 is respectively connected to the desulfurizing agent input pipe 72 and the desulfurizing agent regeneration pipe 223, and the blower 9 provides power for the new desulfurizing agent and the regenerated desulfurizing agent.
[0048] The grinding dryer 2 includes a stirring bin 21 and a powder bin 22. The bottom of the stirring bin 21 is provided with a discharge port 23, and the discharge port 23 is connected to the powder bin 22. The stirring bin 21 includes a shell 24 and an agitator 215, a stirring shaft 218, a driving device 216 and a bracket 217 arranged in the shell 24. The driving device 216 includes a motor and a reduction mechanism for driving the stirring shaft 218 to rotate, and the agitator 215 is connected to the stirring shaft 218. The stirring shaft 218 is connected to the bracket 217 through a bearing, and the stirring shaft 218 is fixed in the shell 24 through the bracket 217 to achieve its own stable rotation. One side of the shell 24 is an arc structure that fits the outer wall of the desulfurization tower 1, and the arc side is welded to the outer wall of the desulfurization tower 1 to ensure that the shell 24 is in close contact with the outer wall of the desulfurization tower 1. In this way, the heat in the desulfurization tower 1 can be directly transferred to the grinding dryer 2 through the tower wall, providing the grinding dryer 2 with heat for drying the bottom sediment of the desulfurization tower 1, thereby improving the energy utilization rate. At the same time, the sediment layer at the bottom of the tower is dried and ground to expose a new desulfurizer surface, thereby improving the use efficiency of the desulfurizer.
[0049] The housing 24 is provided with grinding balls 214, which can be made of stainless steel balls, ceramic balls and other balls that can play a grinding role. When the agitator 215 rotates, the grinding balls 214 and the sediment powder in the stirring chamber 21 are driven to rotate and stir, thereby improving the grinding and drying efficiency. The housing 24 is provided with a sediment inlet 211 and a water vapor outlet 212. The sediment inlet 211 is connected to the outlet of the first delivery pump 5 through a pipeline, and the first delivery pump 5 can be controlled to transport the sediment layer material at the bottom of the tower into the housing 24. The water vapor outlet 212 is connected to the condenser 213, and the outlet of the condenser 213 extends into the bottom of the desulfurization tower 1. The condensed liquid water returns to the bottom of the tower and continues to be recycled, saving water. The condenser 213 is exposed to the external environment, and the outer wall of the condenser 213 is equipped with a circular heat sink 251 to increase the heat dissipation area of the condenser 213 and improve the heat dissipation efficiency. A protective cover 25 is provided outside the heat sink 251 to prevent the high temperature of the heat sink 251 from causing burns to people. At the same time, a plurality of heat dissipation holes 252 are provided on the cover 25 to ensure good heat dissipation effect of the condenser as a whole.
[0050] The housing 24 is provided with a temperature transmitter 104, which is connected to the PLC control system, and the drying temperature in the housing 24 can be monitored in real time through the PLC control system. Because water evaporates at 100°C under normal pressure, when the temperature in the housing 24 reaches 100°C or higher, it can be judged that the precipitate powder is basically dried (in actual operation, when the temperature reaches more than 90 degrees, the moisture content of the powder basically meets the drying requirements), and then the dried powder is discharged through the discharge port 23.
[0051] The discharge port 23 is provided with a rubber sealing pad 231, which is inlaid with the shell 24 around the discharge port 23. A discharge gate 232 is provided on the discharge side of the discharge port 23, and the discharge gate 232 is fitted with the rubber sealing pad 231. The discharge gate 232 and the rubber sealing pad 231 cooperate to prevent water from leaking out of the mixing chamber 21. A gate base 233 is provided under the discharge gate 232, and the gate base 233 is fixedly connected to the shell 24 of the mixing chamber 21. A guide rail that slides with the discharge gate 232 is provided on the gate base 233. The discharge gate 232 is connected to a cylinder 234, which is controlled by a PLC control system, and the cylinder 234 drives the discharge gate 232 to slide on the guide rail. A spring sheet 236 for supporting the discharge gate 232 is provided on the gate base 233 to ensure that the gate is in close contact with the rubber sealing pad 231 when sliding to prevent water leakage. A powder discharge chute 235 matching the discharge port 23 is provided at a part of the discharge gate plate 232 , and the rest of the part is a solid plate.
[0052] In this embodiment, the rubber seal 231 has a certain hardness, and the contact area between the spring sheet 236 and the discharge gate 232 is very small. The surface of the discharge gate 232 is set to be smooth to reduce the friction between the discharge gate 232 and the rubber seal 231 and the spring sheet 236, and the thrust generated by the cylinder 234 is combined to ensure that the discharge gate 232 has good sealing when sliding.
[0053] The specific operation of the PLC control system to control the discharging is as follows: Figure 6 As shown, when the sediment at the bottom of the grinding and drying tower is ground and dried in the grinding and drying device 2, the control cylinder 234 pushes the discharge gate 232 to the right, so that the solid plate portion of the gate seals the discharge port 23 of the grinding and drying device 2; when the sediment is ground and dried into powder, the control cylinder 234 retracts the discharge gate 232 to the left, so that the powder discharge groove 235 on the gate is partially facing the discharge port 23 of the grinding and drying device 2, and the powder falls into the powder silo 22 through the powder discharge groove 235 while being stirred by the agitator 215; when the powder is discharged, the control cylinder 234 pushes the discharge gate 232 to the right again, so that the solid plate portion of the gate seals the discharge port 23 of the housing 24 of the grinding and drying device 2, and the discharge process is completed.
[0054] The powder discharged from the discharge port 23 enters the powder silo 22. The outlet of the powder silo 22 is provided with a fourth delivery pump 221 (in this embodiment, a screw metering pump is used). The fourth delivery pump 221 is connected to the PLC control system, and the discharge amount of the powder in the powder silo 22 can be controlled by the PLC control system. The fourth delivery pump 221 is connected to the waste tank 8 through the waste discharge pipe 222. The waste discharge pipe 222 is provided with a first control valve 107. A branch pipe, i.e., a desulfurizer regeneration pipe 223, is provided on the side wall of the waste discharge pipe 222 between the first control valve 107 and the fourth delivery pump 221. One end of the desulfurizer regeneration pipe 223 is connected to the waste discharge pipe 222, and the other end is connected to the air intake pipe 3. The desulfurizer regeneration pipe 223 is provided with a second control valve 106. The second control valve 106 and the first control valve 107 are both connected to the PLC control system. When the second control valve 106 is opened and the first control valve 107 is closed, the powder discharged from the grinding dryer 2 enters the air intake pipe 3 for recycling; when the second control valve 106 is closed and the first control valve 107 is opened, the powder discharged from the grinding dryer 2 is discharged into the waste tank 8.
[0055] The powder ground and dried in the grinding and drying device 2 contains a certain amount of moisture. When the powder is sprayed into the air intake pipe 3 through the desulfurizer regeneration pipe 223, it will reach the dry packing layer 14 along with the high-temperature flue gas. In this process, the moisture in the desulfurizer powder particles is heated and evaporated, so that gaps are formed inside the powder particles, and an ideal reaction environment with suitable temperature and humidity is formed. At this time, the desulfurizer powder reacts quickly with the sulfur dioxide in the flue gas, and the sulfur dioxide in the flue gas can be quickly removed in the dry packing layer 14, shortening the reaction time. Compared with the traditional method of directly adding the desulfurizer, the above-mentioned desulfurizer regeneration method can reduce the volume of the dry packing layer 14, improve the integration of the desulfurization equipment, and reduce the packing cost.
[0056] The gas outlet pipe 4 is provided with a flue gas analyzer 105, which is connected to the PLC control system and can monitor the sulfur content of the flue gas after desulfurization in real time through the PLC control system. When the regenerated desulfurizer is circulated, if the flue gas analyzer 105 detects that the sulfur content of the flue gas after desulfurization is too high (not up to the emission standard), the fourth delivery pump 221 can be controlled to increase the output of the regenerated powder, thereby increasing the circulation amount of the regenerated desulfurizer and improving the desulfurization effect. When it is found that the circulation amount of the regenerated desulfurizer is large enough but the sulfur content of the flue gas after desulfurization is still not up to standard, it means that the content of the desulfurizer in the regenerated powder is insufficient, and at this time, the regenerated powder can be controlled to be discharged into the waste tank 8.
[0057] A dry and wet flue gas desulfurization treatment method based on the above device has the following steps:
[0058] S1. Add water to the desulfurization tower 1 through the external water supply pipe 31 to make the water level higher than the height of the inlet pipe of the second delivery pump 6. Start the second delivery pump 6 to deliver the water at the bottom of the desulfurization tower 1 to the spray pipe 15 to spray the wet packing layer 16.
[0059] S2. The sulfur-containing flue gas is introduced into the desulfurization tower 1, and the third delivery pump 71 and the blower 9 are started to deliver the new desulfurizer powder to the air inlet pipe 3 to mix with the sulfur-containing flue gas. After the mixed gas enters the desulfurization tower 1, it passes through the dry packing layer 14 and the wet packing layer 16 in sequence, and is then discharged to the outside of the desulfurization tower 1 through the demister 17.
[0060] S3. When a reactant precipitation layer is formed at the bottom of the desulfurization tower 1, the first delivery pump 5 is started to discharge the bottom precipitate into the grinding and drying device 2 for grinding and drying. After grinding and drying into powder, the second control valve 106 is opened, the first control valve 107 is closed, and the fourth delivery pump 221 and the blower 9 are started to transport the powder to the air intake pipe 3 through the desulfurizer regeneration pipe 223, and the powder is mixed with the sulfur-containing flue gas and then enters the desulfurization tower 1; when it is detected that the desulfurizer content in the precipitation layer is lower than a certain proportion (the desulfurizer content is too low and insufficient for desulfurization operation), the second control valve 106 is closed, the first control valve 107 is opened, and the final reaction waste is discharged into the waste tank 8.
[0061] When the circulating water volume at the bottom of the desulfurization tower 1 is lower than a certain liquid volume (ie, the liquid level is lower than the height of the inlet pipe of the second delivery pump 6 ), water is added to the desulfurization tower 1 through the external water supply pipe 31 .
[0062] S4. Repeat steps S1-S3 to complete the continuous desulfurization process of the sulfur-containing flue gas.
[0063] In step S3, the method for judging whether the content of desulfurizer in the precipitation layer is too low is as follows: the approximate desulfurizer consumption is calculated by theoretical calculation according to the flue gas intake and the amount of new desulfurizer added. At the same time, when the regenerated desulfurizer is circulated, if the sulfur content of the flue gas after desulfurization is detected to be too high (not up to the emission standard) by the flue gas analyzer 105, the fourth delivery pump 221 can be controlled to increase the output of the regenerated powder, thereby increasing the circulation amount of the regenerated desulfurizer. When it is found that the circulation amount of the regenerated desulfurizer is large enough and the sulfur content of the flue gas after desulfurization is still not up to standard, it means that the content of desulfurizer in the regenerated powder is too low. At this time, the regenerated powder can be controlled to be discharged into the waste tank 8. After the desulfurization process is stabilized as a whole, it can also be judged empirically that the content of desulfurizer in the precipitation layer is too low according to the number of cycles of the regenerated desulfurizer. Specific embodiment:
[0065] To reduce SO in ship exhaust x The MARPOL 73 / 78 Convention has set clear limits on the sulfur content in ship fuel. Currently, the limit on sulfur content in fuel used by ships sailing on the high seas is 3.5%, but after January 1, 2020, the limit on sulfur content in fuel used by ships sailing on the high seas will be reduced to 0.5%, a decrease of 85.7%. According to regulations, ships can reduce SO by installing exhaust gas post-treatment desulfurization equipment and other measures. x emission.
[0066] The flue gas desulfurization device and method provided by the present invention can treat the sulfur-containing exhaust gas generated by ships sailing on high-sulfur oil fuel, so that the exhaust gas meets the emission standards. At the same time, since the desulfurization treatment device system manufactured by the present invention has the advantages of compact structure, small size, low investment and operating costs, and easy installation and use, it can well meet the requirements of small installation space on ships.
[0067] The specific working principle is as follows: first, circulating water is added to the desulfurization tower 1 through the external water supply pipe 31, the second delivery pump 6 is started, and the wet packing layer 16 is sprayed through the spray pipe 15. The sulfur-containing flue gas discharged from the ship engine enters the desulfurization tower 1 through the air intake pipe 3, and the new desulfurizer powder in the desulfurizer storage tank 7 is metered and output by the third delivery pump 71, and is positively pressured by the air volume output by the blower 9, and is sprayed into the air intake pipe 3 through the desulfurizer input pipe 72. The desulfurizer powder mixes with the flue gas and enters the dry packing layer 14 of the desulfurization tower 1. After the flue gas and the desulfurizer powder are fully contacted and reacted quickly in the outer wall and gap passage of the dry packing layer 14, they enter the wet packing layer 16, and the wet packing layer 16 is moistened by the water mist sprayed from the spray pipe 15 above it. When passing through the wet packing layer 16, the desulfurizer powder is adsorbed by the water film on the surface of the wet packing layer 16, and the remaining sulfur dioxide in the flue gas continues to react with the desulfurizer powder that has absorbed water, removing most of the sulfur dioxide in the flue gas. At the same time, the wet packing layer 16 also filters out the powder ash in the flue gas. The desulfurized and deashed flue gas passes through the demister 17 and is discharged from the gas outlet pipe 4.
[0068] The second delivery pump 6 is controlled by the PLC control system to increase the spraying volume, and the powder adhering to the packing layer is washed to the bottom of the desulfurization tower 1 to form a sedimentation layer reactant at the bottom of the tower. The sediment is pumped into the grinding dryer 2 by the sludge pump, and the inner side of the grinding dryer 2 is close to the outer wall of the desulfurization tower 1. The sediment entering the grinding dryer 2 and the grinding balls 214 are ground by the grinding balls 214 under the stirring of the agitator 215, and on the other hand, the high-temperature flue gas heat conducted from the wall of the desulfurization tower 1 to the grinding dryer 2 is heated, so that the water contained in the sediment evaporates. The evaporated water vapor enters the condenser 213 from the water vapor outlet 212, and returns to the sediment clear water layer of the desulfurization tower 1 after condensing into liquid water. When the water in the sediment in the grinding dryer 2 evaporates to a certain extent to form powder, the temperature in the grinding dryer 2 is detected by the temperature transmitter 104 to judge the water content of the powder. After the powder is dried, the discharge port 23 is controlled to open by the PLC control system to unload the powder into the powder silo 22. The desulfurizer powder is then positively conveyed to the air intake pipe 3 by the second delivery pump 6 and the blower 9 to continue to react with the sulfur dioxide in the flue gas. After the circulating powder in the powder silo 22 has been circulated for many times, when the desulfurizer content in the precipitated powder is too low, the PLC control system discharges the powder in the powder silo 22 into the waste tank 8 through the waste discharge pipe 222.
[0069] The circulating water at the bottom of the desulfurization tower 1 is sprayed onto the wet packing layer 16 and evaporated by the flue gas, which is constantly reduced. When the liquid level transmitter 103 detects that the liquid level is too low, water can be added through the external water supply pipe 31. The sulfur-carbon ratio in the flue gas can be measured by the flue gas analyzer 105 installed on the gas outlet pipe 4, and the desulfurizer output of the second delivery pump 6 and the third delivery pump 71 can be adjusted to meet the emission standards.
[0070] The embodiments described above are merely descriptions of preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.
Claims
1. A dry and wet flue gas desulfurization treatment device, characterized in that: It comprises a desulfurization tower (1), an air inlet pipeline (3), an air outlet pipeline (4), a first delivery pump (5), a second delivery pump (6), a desulfurization agent storage tank (7) and a waste tank (8); The desulfurization tower (1) is provided with a flue gas inlet (11) at the top and a sewage outlet (13) at the bottom, the flue gas inlet (11) is connected to the air inlet pipe (3), the sewage outlet (13) is connected to the inlet of the first delivery pump (5), the outlet of the first delivery pump (5) is connected to the waste tank (8) through a pipe, the desulfurization tower (1) is provided with a dry packing layer (14), a spray pipe (15) and a wet packing layer (16) in sequence from the top to the bottom, a flue gas outlet (12) is provided on the wall of the desulfurization tower (1) between the wet packing layer (16) and the sewage outlet (13), the flue gas outlet (12) is connected to the air outlet pipe (4), and the desulfurization tower (1) is provided with an external water supply pipe (31); The inlet of the second delivery pump (6) is connected to the bottom of the desulfurization tower (1) through a pipeline, and the outlet of the second delivery pump (6) is connected to the spray pipe (15) through a pipeline; A third delivery pump (71) is provided at the outlet of the desulfurizing agent storage tank (7), and the third delivery pump (71) is connected to the air intake pipeline (3) via a desulfurizing agent input pipe (72); A grinding dryer (2) is provided on the pipeline between the first delivery pump (5) and the waste tank (8), the grinding dryer (2) comprising a stirring bin (21) and a powder bin (22), a discharge port (23) is provided at the bottom of the stirring bin (21), the discharge port (23) is connected to the powder bin (22), a sediment inlet (211) and a water vapor outlet (212) are provided on the stirring bin (21), the sediment inlet (211) is connected to the outlet of the first delivery pump (5) via a pipeline, and a fourth delivery pump (212) is provided at the outlet of the powder bin (22). (221), the fourth delivery pump (221) is connected to the waste tank (8) via a waste discharge pipe (222), the waste discharge pipe (222) is provided with a first control valve (107), the waste discharge pipe (222) between the first control valve (107) and the fourth delivery pump (221) is provided with a desulfurizing agent regeneration pipe (223), one end of the desulfurizing agent regeneration pipe (223) is in communication with the waste discharge pipe (222), and the other end is connected to the air intake pipe (3), and the desulfurizing agent regeneration pipe (223) is provided with a second control valve (106).
2. A dry and wet flue gas desulfurization treatment device according to claim 1, characterized in that: The stirring chamber (21) comprises a shell (24), a stirrer (215), a stirring shaft (218), a driving device (216) and a bracket (217); one side of the shell (24) is attached to the outer wall of the desulfurization tower (1) and is fixedly connected to the outer wall of the desulfurization tower (1); the stirrer (215) is connected to the stirring shaft (218); the stirring shaft (218) is connected to the driving device (216); and the stirring shaft (218) is fixed in the shell (24) via the bracket (217); The discharge port (23) is provided with a rubber sealing gasket (231) for covering a shell (24) around the discharge port (23); a discharge gate (232), a gate base (233) and a cylinder (234) are provided on the discharge side of the discharge port (23); the discharge gate (232) is fitted to the rubber sealing gasket (231); a guide rail cooperating with the discharge gate (232) is provided on the gate base (233); the cylinder (234) drives the discharge gate (232) to slide on the guide rail; and a powder discharge trough (235) cooperating with the discharge port (23) is provided on the discharge gate (232).
3. A dry and wet flue gas desulfurization treatment device according to claim 1, characterized in that: It also includes a blower (9), wherein the air outlet pipe (91) of the blower (9) is respectively connected to the desulfurizer input pipe (72) and the desulfurizer regeneration pipe (223), the water vapor outlet (212) is connected to the condenser (213), and the outlet of the condenser (213) extends into the bottom of the desulfurization tower (1).
4. A dry and wet flue gas desulfurization treatment device according to claim 2, characterized in that: A grinding ball (214) is arranged in the housing (24), and the grinding ball (214) is a stainless steel ball or a ceramic ball. A temperature transmitter (104) is arranged on the housing (24), and a spring sheet (236) for supporting the discharge gate (232) is arranged on the gate base (233).
5. The dry and wet flue gas desulfurization treatment device according to claim 1 is characterized in that: The desulfurization tower (1) is provided with a differential pressure transmitter (102) for detecting the pressure difference between the air inlet side and the air outlet side of the wet packing layer (16), the bottom of the desulfurization tower (1) is provided with a liquid level transmitter (103), and the air outlet pipe (4) is provided with a flue gas analyzer (105).
6. A dry and wet flue gas desulfurization treatment device according to claim 1, characterized in that: The smoke outlet (12) is provided with a demister (17), the demister being connected to the gas outlet duct (4), and the fillers in the dry filler layer (14) and the wet filler layer (16) are stainless steel balls for washing, stainless steel wire mesh corrugated fillers or stainless steel calendered punctured corrugated fillers.
7. A dry and wet flue gas desulfurization treatment device according to any one of claims 1 to 6, characterized in that: It also includes a controller, which is connected to the control system (10).
8. A dry and wet flue gas desulfurization method based on the device according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Adding circulating water into the desulfurization tower (1) through the external water supply pipe (31), starting the second delivery pump (6), delivering the circulating water at the bottom of the desulfurization tower (1) to the spray pipe (15), and performing a spraying operation on the wet packing layer (16); S2, introducing sulfur-containing flue gas into the desulfurization tower (1), and starting the third delivery pump (71) and the blower (9) to deliver new desulfurizer powder to the air inlet pipe (3) to mix with the sulfur-containing flue gas. After the mixed gas enters the desulfurization tower (1), it passes through the dry packing layer (14) and the wet packing layer (16) in sequence, and then is discharged to the outside of the desulfurization tower (1) through the demister (17); S3. When a reactant precipitation layer is formed at the bottom of the desulfurization tower (1), the first delivery pump (5) is started to discharge the precipitation at the bottom of the tower into the waste tank (8); when the amount of circulating water at the bottom of the desulfurization tower (1) is lower than a certain liquid volume, water is added to the desulfurization tower (1) through the external water supply pipe (31); S4. Repeat steps S1-S3 to complete the continuous desulfurization process of the sulfur-containing flue gas.
9. A dry and wet flue gas desulfurization treatment method according to claim 8, characterized in that: In step S3, when a reactant precipitation layer is formed at the bottom of the desulfurization tower (1), the first delivery pump (5) is started to discharge the tower bottom precipitation into the grinding and drying device (2) for grinding and drying. After the precipitation is ground and dried into powder, the second control valve (106) is opened, the first control valve (107) is closed, and the fourth delivery pump (221) and the blower (9) are started to transport the powder to the air intake pipe (3) through the desulfurization agent regeneration pipe (223), and the powder is mixed with the sulfur-containing flue gas and then enters the desulfurization tower (1); when it is detected that the desulfurization agent content in the tower bottom precipitation layer is lower than a certain proportion, the second control valve (106) is closed, the first control valve (107) is opened, and the final reaction waste is discharged into the waste tank (8).