Low-emission circulating fluidized bed flue gas purification system

Abstract

The invention discloses a low-emission circulating fluidized bed flue gas purification system, and relates to the field of circulating fluidized bed flue gas purification, the low-emission circulating fluidized bed flue gas purification system comprises a reaction tower, a pulse bag-type dust collector, a fly warehouse and a Venturi dust collector, an activated carbon box for supplying activated carbon and slaked lime and slaked lime are arranged on the side face of the reaction tower, flue gas treated by the reaction tower is conveyed to a pulse bag-type dust collector for further treatment, and the Venturi dust collector conveys water through a water tank with a water pump; pollutants separated from the venturi dust collector and the pulse bag-type dust collector are conveyed into the flying warehouse for treatment; according to the system, through cooperative work of the reaction kettle, the pulse bag-type dust collector and the flying warehouse, harmful substances in flue gas are effectively removed, the flue gas in the pulse bag-type dust collector can be recycled to the Venturi dust collector for secondary treatment, and it is ensured that flue gas emission meets the strict environmental protection standard.

Description

Technical Field

[0001] The invention relates to the field of circulating fluidized bed flue gas purification, in particular to a low-emission circulating fluidized bed flue gas purification system. Background Art

[0002] Circulating fluidized bed flue gas purification technology is one of the commonly used flue gas purification methods in waste incineration power plants. Its principle is to use fly ash circulation to establish a fluidized bed, and spray water into the reaction tower to wet the absorbent, so that the acidic substances in the flue gas and the absorbent can fully react. This technology has the advantages of small footprint and no wastewater discharge, so it has been widely used.

[0003] However, there are some problems in the practical application of the existing circulating fluidized bed flue gas purification technology. For example, in the actual operation of a certain power plant, it was found that there were phenomena such as excessive absorbent consumption, poor process water atomization effect, and easy blockage in the fly ash system of the reaction tower. From the analysis of operating parameters, problems with the process water system and the flow field in the reaction tower are the main factors that lead to the inability to establish a circulating fluidized state. Specifically, direct water spray atomization can easily cause water to be carried in the flue gas, resulting in the "bag sticking" phenomenon in the bag filter, and the absorption tower will also have wet wall problems. The fluidization state in the reaction tower is unstable and the bed often collapses. This is because the outlet airflow distribution of the Venturi tube is uneven and the flow field is unstable, which affects the stability of the bed layer of the reaction tower, resulting in low deacidification efficiency and large amount of absorbent. Summary of the invention

[0004] In order to fill the gap in the market, the present invention provides a low-emission circulating fluidized bed flue gas purification system.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a low-emission circulating fluidized bed flue gas purification system, comprising a reaction tower, a pulse bag dust collector, a fly tank and a venturi dust collector, the flue gas is transported to the inside of the reaction tower through a pipeline through the venturi dust collector, in this process, the venturi dust collector plays a role in preliminary treatment and diversion of the flue gas; and an activated carbon box and slaked lime for supplying activated carbon and slaked lime are arranged on the side of the reaction tower, the activated carbon and slaked lime are used as adsorbents and reactants for removing harmful substances in the flue gas; after the reaction tower treats The flue gas is transported to the pulse bag filter for further treatment and then transported to the flue through the induced draft fan, which provides power for the transportation of the flue gas. After the control valve is closed, the flue gas inside the pulse bag filter is transported to the Venturi filter through the circulation pipeline for secondary treatment. The Venturi filter uses a water tank with a water pump to transport water, which is used to cool, humidify and assist in the purification process of the flue gas. The pollutants separated in the Venturi filter and the pulse bag filter are transported to the fly storage for internal treatment. The fly storage serves as a centralized storage and treatment area for pollutants. The Venturi dust collector comprises a contraction tube at the bottom, a mixed flow throat connected to the front end of the contraction tube, and a diffuser connected to the mixed flow throat; the contraction tube is used to accelerate the flue gas to enter the mixed flow throat, which is a key mixing area, and the diffuser allows the treated flue gas to flow out smoothly; and the mixed flow throat is connected to a water distribution pipe evenly arranged on the side, the water distribution pipe is used to transport water, and an annular water supply pipe is connected to the upper end of the water distribution pipe, and the water supply pipe can ensure that the water is evenly transported to the water distribution pipe; The mixed flow throat includes a main pipe in the middle and branch pipes evenly arranged in the middle of the main pipe. The main pipe is the main gas channel, and the branch pipe is used to introduce other gases or substances. A converging channel is opened inside the branch pipe, and the cross-section of the converging channel is a V-shaped structure. This special structure is conducive to the mixing of gases and substances and improves the purification efficiency.

[0006] Furthermore, the reaction tower is provided with a structure for adjusting the uniformity of the flow field, and a combination mode of multiple small venturi tubes is adopted. This combination mode can more accurately control the flow rate and direction of the flue gas; the throat flow rate is designed according to a specific speed, and a straightening section and a guide plate are provided. The straightening section can make the incoming flue gas more stable, and the guide plate can guide the flow direction of the flue gas to ensure uniform distribution of the flue gas flow at the inlet of the reaction tower, thereby improving the stability of the fluidized bed in the reaction tower, reducing the bed collapse phenomenon, and improving the utilization rate of the absorbent and the actual deacidification efficiency.

[0007] Furthermore, it also includes a control system, which adopts interlocking control of the atomization system and control of the circulating ash concentration; when the inlet flue gas temperature is lower than 170°C or the differential pressure of the absorption tower bed is too small, the atomization water spray system cannot be started, which can avoid a series of problems caused by unreasonable water spraying; at the same time, in order to improve the deacidification efficiency, it is necessary to control the circulating ash concentration; the establishment of the circulating ash system is closely related to the circulating ash hopper at the bottom of the bag filter; the ash collected by the bag filter enters the circulating ash hopper of the circulating ash system, and the fluidizing chute at the bottom of the circulating ash hopper will return this part of the ash to the reaction tower to form a material circulation to ensure the establishment of the fluidized state in the reaction tower; the return amount of circulating ash is the key to maintaining a stable pressure difference of the fluidized bed in the tower, which is adjusted by the pressure difference of the reaction tower and the flue gas flow rate; due to the large differential pressure of the reaction tower, the amount of the circulating ash hopper needs to be guaranteed, so this optimization adopts the partitioned fluidizing air pressure to remotely control and monitor the ash amount of the circulating ash hopper to ensure the operation of the circulating ash system and improve the stability and purification efficiency of the entire flue gas purification system.

[0008] Furthermore, the inner wall of the contraction tube has a special spiral texture, which enables the flue gas to be accelerated more evenly before entering the mixed flow throat, reducing the generation of local turbulence. A flow regulating device is provided at the inlet of the contraction tube, which can automatically adjust the opening of the inlet according to the flue gas flow entering the Venturi dust collector to ensure that the incoming flue gas flow is stable within an appropriate range; this flow regulating device adopts a high-precision sensor and an intelligent control system, which can monitor the flue gas flow in real time and make rapid adjustments when the flow exceeds the set range; the material of the contraction tube is a high-temperature resistant and corrosion-resistant alloy material.

[0009] Furthermore, the inner wall of the main pipe is coated with a special catalytic coating; the catalytic coating can promote chemical reactions between certain harmful gases in the flue gas and the injected water or other added substances; the components of the catalytic coating include a variety of metal oxides and rare earth elements, and the opening angle and size of the branch pipe can be adjusted. Through an external adjustment device, the opening state of the branch pipe can be accurately adjusted according to different flue gas components and purification requirements, thereby controlling the material flow and mixing ratio entering the confluence channel; the V-shaped cross-sectional structure of the confluence channel is provided with guide protrusions on the side close to the main pipe, and these guide protrusions can further guide the mixed gas and material to flow more smoothly in the confluence channel, avoiding backflow and dead zone phenomena.

[0010] Furthermore, the inner wall of the diffuser is in a gradually expanding curved shape, so that the flue gas gradually slows down and diffuses evenly after flowing out of the mixed flow throat; an anti-backflow device is provided at the outlet of the diffuser, which is composed of a group of blades, and the angle and arrangement of the blades can effectively prevent the flue gas from flowing back into the diffuser; the material of the diffuser adopts a composite material with good thermal insulation performance; the connection part between the diffuser and the mixed flow throat adopts a sealing structure with good sealing performance, which can prevent flue gas leakage and ensure the purification efficiency of the entire Venturi dust collector.

[0011] Furthermore, the inner wall of the reaction tower is provided with a plurality of adsorption layers, which include activated carbon fibers and molecular sieves; a stirring device is also provided inside the reaction tower, which is composed of a motor, a stirring shaft and stirring blades; a discharge port is provided at the bottom of the reaction tower, and an automatic control valve is provided at the discharge port. When the solid waste generated during the adsorption and reaction process reaches a certain amount, the automatic control valve can automatically open to discharge the waste from the reaction tower to ensure the normal operation of the reaction tower.

[0012] Furthermore, a cleaning device is provided inside the pulse bag dust collector. The cleaning device adopts pulse spraying technology and can clean the bags regularly. The pressure and frequency of the pulse spraying are adjustable. According to the dust content in the flue gas and the blockage of the bags, the cleaning parameters can be flexibly adjusted to ensure the air permeability and dust removal efficiency of the bags.

[0013] Furthermore, the interior of the flying reservoir is provided with a plurality of partitioned areas, which are used for classified storage of different types of pollutants delivered from the Venturi dust collector and the pulse bag dust collector; each partitioned area is equipped with an independent monitoring system, which can monitor the quantity, composition and state of the pollutants in real time; a ventilation system is provided on the top of the flying reservoir, which can maintain air circulation inside the flying reservoir and prevent the accumulation of harmful gases; a drain port is provided at the bottom of the flying reservoir, and when the pollutants contain liquid components, the drain port can discharge the liquid out of the flying reservoir.

[0014] Furthermore, a water level monitoring device is provided inside the water tank, which can monitor the water level height in the water tank in real time; the water level monitoring device adopts a high-precision sensor, which can accurately feedback water level information; a water replenishment port is provided on the top of the water tank, and the water replenishment port is connected to an automatic water replenishment system. When the water level is lower than the set value, the automatic water replenishment system can automatically replenish water into the water tank; a water outlet is provided at the bottom of the water tank, and the water outlet is connected to a water pump. The water pump can transport the water in the water tank to the water supply pipe of the Venturi dust collector; the outer shell of the water tank is made of anti-corrosion material, which can prevent the water tank from rusting and ensure the normal use of the water tank; the water tank is also provided with a temperature regulating device, which can adjust the temperature of the water in the water tank so that the temperature of the water transported to the Venturi dust collector meets the purification requirements.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This system forms a complete and efficient flue gas purification process through the coordinated work of the reactor, pulse bag dust collector and fly warehouse; the flue gas first enters the reactor after preliminary treatment by the Venturi dust collector. The activated carbon box and slaked lime supply device installed on the side of the reactor can provide the necessary adsorbent and reactant for the reaction, effectively removing harmful substances in the flue gas. The treated flue gas then enters the pulse bag dust collector for further dust removal, and is finally transported to the flue through the induced draft fan. When the control valve is closed, the flue gas in the pulse bag dust collector can be circulated back to the Venturi dust collector for secondary treatment, which greatly improves the purification effect and ensures that the flue gas emissions meet strict environmental protection standards.

[0016] The pollutants separated by the Venturi dust collector and the pulse bag dust collector are transported to the inside of the Feiku for treatment; multiple partitioned areas are set up inside the Feiku for classified storage of different types of pollutants, and an independent monitoring system is equipped to monitor the status of pollutants in real time; the ventilation system on the top prevents the accumulation of harmful gases, and the drain port at the bottom can discharge liquid pollutants. The corrosion-resistant material of the outer shell ensures its service life and safety, realizing safe and effective treatment of pollutants.

[0017] The special texture design of the inner wall of the contraction tube enables the flue gas to form a specific flow field distribution during the contraction process, evenly accelerating it into the mixed flow throat, reducing local turbulence and improving purification efficiency; the flow regulating device at the inlet can automatically adjust the inlet opening to ensure stable flue gas flow, and cooperate with high-precision sensors and intelligent control systems to monitor and adjust the flow in real time, ensuring the stable operation of the system; at the same time, the selection of high-temperature and corrosion-resistant alloy materials enables it to maintain good performance in harsh environments and extend its service life.

[0018] The catalytic coating on the inner wall of the mixed flow throat main pipe promotes the chemical reaction between harmful gases and other substances, improving the purification effect; the opening angle and size of the branch pipe are adjustable, and the material flow and mixing ratio can be accurately controlled according to different needs; the guide protrusions in the converging channel further guide the gas and material to flow smoothly, avoiding backflow and dead zone phenomena, so that the flue gas can be fully mixed and reacted in the mixed flow throat, improving the overall purification performance.

[0019] The gradually expanding curve shape of the inner wall of the diffusion tube is designed according to the principles of fluid mechanics, which makes the flue gas gradually slow down and diffuse evenly; the anti-backflow device at the outlet effectively prevents the backflow of flue gas and ensures the unidirectionality of the purification process; the composite shell with good thermal insulation performance reduces heat loss and maintains the appropriate temperature and humidity of the flue gas; the sealed connection structure with the mixed flow throat prevents flue gas leakage and ensures the purification efficiency of the Venturi dust collector.

[0020] The water level monitoring device inside the water tank uses a high-precision sensor to monitor the water level in real time. The water replenishment port on the top is connected to the automatic water replenishment system. When the water level is lower than the set value, water is automatically replenished to ensure that there is sufficient water in the water tank; the bottom water outlet is connected to a water pump to transport water to the Venturi dust collector; the anti-corrosion material of the outer shell prevents rust, and the temperature regulating device can adjust the water temperature so that the temperature of the water transported to the Venturi dust collector meets the purification requirements, ensuring the stability and effectiveness of the water transport of the Venturi dust collector, and helping to improve the flue gas purification effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the flue gas purification process of the circulating fluidized bed structure of the present invention; Figure 2 A schematic diagram of the Venturi dust collector of the present invention; Figure 3 Schematic diagram of the mixed flow throat in the present invention.

[0022] In the figure: 1. Activated carbon box; 2. Slaked lime; 3. Reaction tower; 4. Pulse bag filter; 5. Induced draft fan; 6. Control valve; 7. Flue; 8. Flying reservoir; 9. Venturi filter; 91. Contraction pipe; 92. Mixed flow throat; 921. Branch pipe; 922. Converging channel; 923. Main pipe; 93. Water distribution pipe; 94. Water supply pipe; 95. Diffuser; 10. Water tank. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] See also Figure 1-3 The invention provides a technical solution: a low-emission circulating fluidized bed flue gas purification system, firstly installing the reactor 3, fixing it on a pre-designed foundation, ensuring that the horizontality and verticality meet the requirements. The installation position of the reactor 3 should be convenient for the connection of the activated carbon box 1 and the slaked lime 2, and should have a suitable pipeline connection interface with the subsequent pulse bag filter 4.

[0025] Then install the pulse bag dust collector 4. During the installation process, it should be noted that its inlet and outlet directions are consistent with the design, and it should be tightly connected with the reactor 3 and the induced draft fan 5 through the pipeline. The installation height of the pulse bag dust collector 4 should take into account the convenience of the cleaning device and the smoothness of dust discharge.

[0026] The installation of the venturi dust collector 9 must be accurate, and its contraction tube 91, mixed flow throat 92 and diffusion tube 95 must be assembled according to the design requirements. The venturi dust collector 9 is connected to the reactor 3 through a pipeline, and must be correctly connected to the water supply pipeline of the water tank 10 to ensure that the water can be normally transported to the inside of the venturi dust collector 9.

[0027] The flying reservoir 8 is installed in a suitable position to receive pollutants delivered by the venturi dust collector 9 and the pulse bag dust collector 4. The connecting pipes between the flying reservoir 8 and the two should be well sealed to prevent leakage of pollutants.

[0028] Finally, the water tank 10 is installed. The water tank 10 should be installed at a position higher than the venturi dust collector 9 so as to utilize gravity to realize the natural transportation of the water body. A valve should be installed on the connecting pipe between the water tank 10 and the venturi dust collector 9 so as to control the water flow.

[0029] The shrink tube 91 is made of high temperature resistant and corrosion resistant alloy material. First, the raw material is cut according to the design size, and the cutting accuracy is controlled within ±0.5mm. Then, the cut material is formed by precision processing technology to form a special texture on its inner wall. The texture is processed by CNC processing technology according to the pre-designed texture shape and direction program to ensure the accuracy and consistency of the texture.

[0030] During the processing, the shrink tube 91 is subjected to multiple quality inspections, including dimensional accuracy inspection, material performance inspection, etc. The dimensional accuracy inspection uses a three-coordinate measuring machine to ensure that the inner diameter, outer diameter and length of the shrink tube 91 meet the design requirements. The material performance inspection includes the inspection of the hardness, toughness, corrosion resistance and other aspects of the alloy material, and professional inspection equipment and methods are used to ensure that the material performance meets the requirements for use in a high-temperature flue gas environment.

[0031] The shrink tube 91 is installed at the bottom of the venturi dust collector 9. During installation, ensure that the connection with the mixed flow throat 92 is tight and leak-free. Use sealing gaskets and sealants to seal the connection parts. The sealing gaskets should be made of high temperature resistant and corrosion resistant materials, such as polytetrafluoroethylene gaskets. During the installation process, use special installation tools to ensure that the shrink tube 91 is installed in an accurate position and concentric with the overall structure of the venturi dust collector 9.

[0032] The main pipe 923 and the branch pipe 921 of the mixed flow throat 92 are manufactured using different processes. The main pipe 923 is manufactured using a seamless steel pipe, which is first cut and processed to meet the design requirements. Then, a catalytic coating is applied to the inner wall of the main pipe 923. The catalytic coating is applied using a special spraying process, and the pre-prepared catalytic coating is evenly sprayed on the inner wall of the main pipe 923, and the coating thickness is controlled to be between 0.1 and 0.3 mm.

[0033] The branch pipe 921 is made of stainless steel pipe, and is cut and bent according to the design requirements so that its opening angle and size meet the design requirements. A confluence channel 922 is opened inside the branch pipe 921, and the confluence channel 922 is processed by CNC processing technology to ensure that the cross-section of the confluence channel 922 is a V-shaped structure and the dimensional accuracy meets the design requirements.

[0034] The mixed flow throat 92 is installed at the front end of the shrink tube 91. During installation, ensure that the main pipe 923 is tightly connected to the shrink tube 91 and the opening direction of the branch pipe 921 is correct. Use sealing welding to connect the connection parts to ensure that there is no leakage in the connection parts. During the installation process, use special installation tools and equipment to ensure that the installation position of the mixed flow throat 92 is accurate and consistent with the overall structure of the Venturi dust collector 9.

[0035] The diffuser 95 is made of a composite material with good thermal insulation performance. First, the raw materials are cut according to the design size, and the cutting accuracy must be controlled within ±0.5mm. Then, the cut material is molded using a mold forming process so that its inner wall is in a gradually expanding curved shape. During the processing, the diffuser 95 must be subjected to multiple quality inspections, including dimensional accuracy inspections and material performance inspections. The dimensional accuracy inspection uses a three-coordinate measuring instrument to ensure that the inner diameter, outer diameter and length of the diffuser 95 meet the design requirements. Material performance testing includes testing of the thermal insulation performance, mechanical properties and other aspects of the composite material, and professional testing equipment and methods are used to ensure that the material performance meets the use requirements in the smoke diffusion process.

[0036] The diffuser 95 is installed at the front end of the mixed flow throat 92. During installation, it is necessary to ensure that the connection with the mixed flow throat 92 is tight and leak-free. The connection part is sealed with a sealing gasket and a sealant. The sealing gasket should be made of a high temperature resistant and corrosion resistant material, such as a polytetrafluoroethylene gasket. During the installation process, a special installation tool should be used to ensure that the diffuser 95 is installed in an accurate position and is concentric with the overall structure of the venturi dust collector 9.

[0037] The inner wall of the reactor 3 is provided with multiple adsorption layers, and the thickness of each adsorption layer is set according to the design requirements, generally between 5 and 10 mm. The adsorption layers are separated by spacer materials, and the spacer materials are selected from high temperature resistant and insulating materials, such as ceramic fibers.

[0038] Different adsorption layers use different adsorption materials. The adsorption layer closest to the inner wall of the reactor 3 uses activated carbon fiber, which has a large specific surface area and good adsorption performance, and can effectively adsorb organic pollutants in the flue gas. The middle adsorption layer uses molecular sieves, which have a good adsorption effect on some small molecular pollutants in the flue gas. The outermost adsorption layer uses activated alumina, which can adsorb moisture and some acidic gases in the flue gas.

[0039] The motor of the stirring device is installed on the top of the reactor 3. The motor should be installed firmly and well sealed with the top of the reactor 3 to prevent smoke leakage. The stirring shaft is inserted into the reactor 3 through the sealed bearing on the top of the reactor 3. The sealed bearing should be high temperature resistant and corrosion resistant, such as ceramic bearings. The stirring blades are installed on the stirring shaft. The installation angle and arrangement of the stirring blades should be adjusted according to the design requirements to ensure that a complex flow field is formed in the reactor 3.

[0040] After the stirring device is installed, it needs to be debugged. First, start the motor and observe the rotation of the stirring shaft and the stirring blades to ensure smooth rotation without jamming. Then, adjust the angle and arrangement of the stirring blades and optimize them according to the flow field conditions in the reactor 3 to fully mix the flue gas, activated carbon, slaked lime and other materials. During the debugging process, monitor the temperature and pressure changes in the reactor 3 to ensure that the temperature and pressure are within a safe range.

[0041] A discharge port is provided at the bottom of the reactor 3. The diameter of the discharge port is designed according to the size of the reactor 3 and the discharge volume requirement, and is generally between 50 and 100 mm. An automatic control valve is provided at the discharge port. The automatic control valve adopts an electric valve. The electric valve is connected to the control system of the reactor 3 so as to automatically control according to the accumulation of solid waste in the reactor 3.

[0042] The bags of pulse bag filter 4 use a new type of filter material, which has a higher porosity and a smaller pore size, and can effectively filter tiny particles in the flue gas. The material of the bag is a composite material of polyester fiber and polytetrafluoroethylene, which has good mechanical properties and chemical stability. The surface of the bag has been specially treated to have good antistatic properties and hydrophobicity, which can prevent dust adsorption and bag clogging.

[0043] When selecting bags, you also need to consider factors such as flue gas temperature, humidity, chemical composition, and dust characteristics. For example, if the flue gas contains a high concentration of acidic gases, such as sulfur dioxide or hydrogen chloride, you need to choose a bag material with better acid resistance, or give the bag a special acid-proof treatment to ensure that the bag will not be corroded and damaged during long-term operation, thereby ensuring its filtration performance and service life.

[0044] The bag is installed on the internal frame of the pulse bag dust collector 4. During installation, ensure that the bag is firmly installed without wrinkles and looseness. The bag should be installed according to the design requirements, ensure that the inlet and outlet directions of the bag are correct, and cooperate well with the dust cleaning device of the pulse bag dust collector 4.

[0045] During the installation process, first fix one end of the bag to the corresponding position on the internal frame, and then gradually unfold the bag to evenly cover the frame. When fixing the other end, pay attention to adjusting the tension of the bag so that it is neither too tight to cause easy damage nor too loose to affect the filtering effect. At the same time, use special installation tools, such as bag clamps, to ensure that the bag is installed in the correct position and is consistent with the overall structure of the pulse bag dust collector 4.

[0046] The dust cleaning device adopts advanced pulse spraying technology and is installed on the top of the pulse bag dust collector 4. The pulse spraying device includes components such as a pulse generator, a spraying pipe and a spraying nozzle.

[0047] The pulse generator is installed on the top of the pulse bag dust collector 4. It should be installed firmly and connected tightly to the injection pipe. When installing the pulse generator, make sure that its installation position is horizontal to ensure its normal operation. At the same time, it should be connected to the control system so that it can receive the control signal for accurate pulse output.

[0048] The spray pipe is installed inside the pulse bag dust collector 4, and should be consistent with the arrangement direction of the bags, and should be tightly connected to the spray nozzle. The spray pipe should be installed vertically to avoid deflection during the spraying process, which will affect the cleaning effect. During the installation process, the direction and branches of the spray pipe should be reasonably designed according to the arrangement layout of the bags to ensure that each bag can be effectively cleaned.

[0049] The nozzle is installed at the end of the blowing pipe and should be aligned with the center of the bag to facilitate effective cleaning of the bag. The nozzle should be installed at a precise angle, generally perpendicular to the bag surface, with a deviation of no more than ±5°. When installing the nozzle, pay attention to the tightness of the connection with the blowing pipe to prevent air leakage during the blowing process, which will affect the cleaning effect.

[0050] After the dust removal device is installed, it is necessary to debug it. First, start the pulse generator and observe the working conditions of the spray pipe and spray nozzle to ensure that the spray is normal and leak-free. When starting the pulse generator, gradually increase the output power and observe the spray effect and the reaction of the bag.

[0051] Then, adjust the output power and spray frequency of the pulse generator, and optimize according to the dust content in the flue gas and the blockage of the bag to ensure the air permeability and dust removal efficiency of the bag. If the dust content in the flue gas is high, it may be necessary to increase the spray frequency and appropriately increase the output power; if the bag is seriously blocked, it is also necessary to adjust the spray parameters accordingly to restore the air permeability of the bag as soon as possible.

[0052] During the debugging process, monitor the pressure changes in the pulse bag filter 4 to ensure that the pressure is within a safe range. If the pressure is too high, it may cause bag damage or other equipment failures. It is necessary to adjust the cleaning parameters in time or check whether the equipment is blocked.

[0053] The shell of the pulse bag filter 4 is made of solid metal materials, such as carbon steel or stainless steel. First, the raw materials are cut according to the design size, and the cutting accuracy should be controlled within ±0.5mm. Then, the cut materials are assembled using welding technology, and the welding technology must comply with relevant standards to ensure welding quality.

[0054] During the welding process, attention should be paid to the selection of welding sequence and welding parameters. For larger shells, segmented welding is generally adopted, first welding the main structural parts, then welding the secondary parts, to reduce welding deformation. Welding parameters such as current, voltage and welding speed should be reasonably adjusted according to the selected metal material and the thickness of the welding part to ensure welding quality.

[0055] After welding, the shell should be surface treated, such as painting or galvanizing, to improve the anti-corrosion performance of the shell. If painting is used, choose the right type of paint, such as epoxy paint, which has good corrosion resistance and wear resistance. When painting, ensure that the paint is evenly sprayed and the coating thickness meets the requirements, generally between 80-120μm. If galvanizing is used, ensure that the galvanized layer is uniform and dense to improve the anti-corrosion performance of the shell.

[0056] The shell is installed on the outside of the pulse bag dust collector 4. During installation, ensure that the shell is firmly installed and fits tightly with the internal structure of the pulse bag dust collector 4 without any gap. During the installation process, use appropriate installation tools, such as bolts, nuts, etc., to fix the shell to the internal structure.

[0057] It is important to note that the inlet and outlet positions of the housing should be consistent with the design requirements to ensure that the flue gas can smoothly enter and exit the pulse bag dust collector 4. At the same time, check the sealing of the housing to prevent flue gas leakage. Sealing strips or sealing gaskets and other materials can be used to seal the inlet and outlet and connection parts to improve the sealing of the housing.

[0058] A plurality of partition areas are arranged inside the fly storehouse 8, and the number and size of the partition areas are determined according to the type and amount of pollutants to be processed. For example, different partition areas can be arranged for pollutants containing more water separated from the venturi dust collector 9 and dry dust pollutants separated from the pulse bag dust collector 4. Generally, it is more appropriate to arrange 3-5 partition areas.

[0059] The materials for the separation area should be corrosion-resistant, high-strength plastic or metal. For areas that may be exposed to acidic pollutants, acid-resistant plastics such as polyvinyl chloride (PVC) or polyethylene (PE) are used, which have good corrosion resistance and chemical stability. For areas that are subject to greater pressure, such as the bottom where more pollutants may accumulate, metal materials such as stainless steel are used to ensure structural strength.

[0060] A monitoring system is installed in each compartment. The monitoring system includes sensors and data acquisition devices. Sensors are used to detect parameters such as the quantity, composition and state of pollutants. For example, mass sensors are installed to detect the weight of pollutants, gas sensors are installed to detect the concentration of harmful gases, and humidity sensors are installed to detect the humidity of pollutants. Sensors should be installed in appropriate locations to accurately obtain relevant data.

[0061] The data acquisition device is connected to the sensor to collect the data collected by the sensor and transmit the data to the control system. The data acquisition device should be installed outside the separation area to avoid corrosion by pollutants and ensure that the connection with the sensor is stable and reliable.

[0062] The monitoring system is configured reasonably according to different pollutant types and monitoring requirements. Different monitoring parameters and thresholds can be set for different separation areas. For example, for separation areas containing acid gas, a lower acid gas concentration threshold is set, and when the acid gas concentration exceeds the threshold, an alarm is issued in time.

[0063] A ventilation system is arranged on the top of the flying storehouse 8, and the ventilation system includes ventilation ducts and ventilation fans. The design of the ventilation ducts should ensure that the entire internal space of the flying storehouse 8 can be covered so that the air can circulate evenly. The diameter of the ventilation ducts is determined according to the size of the flying storehouse 8 and the ventilation volume requirements, and is generally between 10-20 cm.

[0064] The ventilation fan should select the appropriate power and air volume, which should be determined according to the amount of harmful gases that may be generated in the flying storehouse 8 and the ventilation requirements. The ventilation fan should be installed at one end of the ventilation duct to ensure that the air in the flying storehouse 8 can be effectively extracted to maintain air circulation.

[0065] A discharge port is provided at the bottom of the fly reservoir 8, and the diameter of the discharge port is determined according to the amount of liquid that may be discharged, generally between 2-5 cm. A valve should be provided at the discharge port, and the valve should be able to conveniently control the discharge of the liquid, and should be made of corrosion-resistant materials, such as stainless steel or plastic valves.

[0066] During the installation process, the ventilation system and the drain port must be well sealed to prevent the leakage of harmful gases and liquids. The connection between the ventilation duct and the fly storage 8 should be sealed with sealing materials, such as sealant or rubber gasket. The valve of the drain port should be installed firmly and connected tightly to the drain pipe.

[0067] A water level monitoring device is provided inside the water tank 10. The water level monitoring device uses a high-precision sensor, such as a capacitive water level sensor or an ultrasonic water level sensor. The sensor should be installed at a suitable position of the water tank 10 to accurately measure the water level. Generally, the sensor is installed in the middle of the side or the top of the water tank 10 to avoid being affected by impurities at the bottom of the water tank.

[0068] A water filling port is provided at the top of the water tank 10, and the water filling port is connected to an automatic water filling system. The diameter of the water filling port is determined according to the water filling speed and the size of the water tank, and is generally between 1 and 2 cm. A valve is provided at the water filling port, and the valve is capable of conveniently controlling the water filling process.

[0069] During the installation process, the water level monitoring device must be firmly installed and tightly connected to the water tank 10, and the sensor must be waterproofed to prevent moisture from entering the sensor and affecting the measurement accuracy. The valve of the water supply port must be firmly installed and tightly connected to the water supply system, and the valve must be able to work normally.

[0070] The water outlet is arranged at the bottom of the water tank 10, and the diameter of the water outlet is determined according to the water flow requirement, generally between 1-2 cm. The water outlet is to be connected to a water pump, and a suitable connection method, such as a flexible connecting pipe, is to be adopted between the water outlet and the water pump to prevent leakage of the connection part due to vibration and the like.

[0071] The water pump should be installed in a suitable position near the water tank 10. Make sure that the water pump is firmly installed and well connected to the power supply and control system. The selection of the water pump should be determined based on the distance from the water tank 10 to the Venturi dust collector 9, the required water flow and head, etc. During the installation process, the water pump should be debugged to ensure that the water pump can work normally and can deliver water to the Venturi dust collector 9 as required.

[0072] The shell of the water tank 10 is made of anti-corrosion material, such as stainless steel or glass fiber reinforced plastic. Stainless steel has good mechanical properties and anti-corrosion ability, while glass fiber reinforced plastic has good corrosion resistance and insulation. Select the appropriate shell material according to actual conditions.

[0073] The water tank 10 is provided with a temperature regulating device, which includes a heating element and a cooling element. The heating element is used to increase the water temperature when the water temperature is too low, and the cooling element is used to reduce the water temperature when the water temperature is too high. The temperature regulating device should determine the appropriate power and type according to the size of the water tank 10 and the required temperature regulation range.

[0074] The housing material should be firmly installed during installation and tightly connected to the water tank 10. The temperature regulating device should be installed at a suitable position of the water tank 10 to effectively regulate the water temperature. For example, the heating element can be installed at the bottom of the water tank 10, and the cooling element can be installed at the top of the water tank 10, so as to effectively regulate the water temperature.

[0075] The control system includes a controller, a sensor and an actuator. The controller uses a programmable logic controller PLC, which has strong logic control capabilities and reliability. The sensors include an inlet flue gas temperature sensor and an absorption tower bed differential pressure sensor. The inlet flue gas temperature sensor is installed at the inlet of the reactor 3 to detect the inlet flue gas temperature. The absorption tower bed differential pressure sensor is installed in the reaction tower to detect the absorption tower bed differential pressure. The actuator includes an electric valve and a water pump of the atomizing water spray system.

[0076] When the inlet flue gas temperature is lower than 170°C or the differential pressure of the absorber bed is too small, the controller will close the electric valve and water pump of the atomizing water spray system and stop the atomizing water spray process according to the data collected by the sensor through control logic judgment. When the inlet flue gas temperature is higher than 170°C and the differential pressure of the absorber bed is normal, the controller will open the electric valve and water pump to start the atomizing water spray system.

[0077] The circulating ash concentration control involves the circulating ash hopper, fluidizing chute, and related sensors and actuators at the bottom of the bag filter. The circulating ash hopper is used to collect the ash collected by the bag filter, and the fluidizing chute is used to return the ash to the reaction tower. The sensors include a circulating ash weight sensor and a reaction tower pressure difference sensor. The circulating ash weight sensor is installed in the circulating ash hopper to detect the weight of the circulating ash.

[0078] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A low-emission circulating fluidized bed flue gas purification system, comprising a reaction tower (3), a pulse bag filter (4), a fly silo (8) and a venturi filter (9), characterized in that: The flue gas is transported to the interior of the reaction tower (3) through a pipeline and a venturi dust collector (9). During this process, the venturi dust collector (9) plays a role in preliminary treatment and diversion of the flue gas. An activated carbon box (1) and slaked lime (2) for supplying activated carbon and slaked lime are provided on the side of the reaction tower (3). The activated carbon and slaked lime serve as adsorbents and reactants for removing harmful substances in the flue gas. The flue gas treated by the reaction tower (3) is transported to a pulse bag dust collector (4) for further treatment and then transported to a flue (7) through an induced draft fan (5). The induced draft fan (5) provides power for the transportation of the flue gas; after the control valve (6) is closed, the flue gas inside the pulse bag filter (4) is transported to the venturi filter (9) through a circulation pipeline for secondary treatment. The venturi filter (9) transports water through a water tank (10) with a water pump. The water is used to cool and humidify the flue gas and assist in the purification process. The pollutants separated in the venturi filter (9) and the pulse bag filter (4) are transported to the fly storage (8) for internal treatment. The fly storage (8) serves as a centralized storage and treatment area for pollutants. The venturi dust collector (9) comprises a contraction tube (91) at the bottom, a mixed flow throat (92) connected to the front end of the contraction tube (91), and a diffuser (95) connected to the mixed flow throat (92); the contraction tube (91) is used to accelerate the flue gas to enter the mixed flow throat (92), the mixed flow throat (92) is a key mixing area, and the diffuser (95) allows the treated flue gas to flow out smoothly; and the mixed flow throat (92) is connected to a water distribution pipe (93) evenly arranged on the side, the water distribution pipe (93) is used to transport water, and the upper end of the water distribution pipe (93) is connected to a ring-shaped water supply pipe (94), and the water supply pipe (94) can ensure that the water is evenly transported to the water distribution pipe (93); The mixed flow throat (92) comprises a main pipe (923) in the middle and branch pipes (921) evenly arranged in the middle of the main pipe (923). The main pipe (923) is the main gas passage, and the branch pipe (921) is used to introduce other gases or substances. A converging channel (922) is provided inside the branch pipe (921). The cross section of the converging channel (922) is a V-shaped structure. This special structure is conducive to the mixing of gas and substances, thereby improving the purification efficiency.

2. A low emission circulating fluidized bed flue gas purification system according to claim 1, characterized in that: The reaction tower (3) is provided with a structure for adjusting the uniformity of the flow field, and adopts a combination mode of multiple small venturi tubes. This combination mode can more accurately control the flow rate and flow direction of the flue gas; the throat flow rate is designed according to a specific speed, and a rectifying section and a guide plate are provided. The rectifying section can make the incoming flue gas more stable, and the guide plate can guide the flow direction of the flue gas, thereby ensuring that the flue gas flow at the inlet of the reaction tower is evenly distributed, thereby improving the stability of the fluidized bed in the reaction tower, reducing the bed collapse phenomenon, and improving the utilization rate of the absorbent and the actual deacidification efficiency.

3. A low emission circulating fluidized bed flue gas purification system according to claim 2, characterized in that: It also includes a control system, which adopts interlocking control of the atomization system and control of the circulating ash concentration; when the inlet flue gas temperature is lower than 170°C or the differential pressure of the absorption tower bed is too small, the atomization water spray system cannot be started, which can avoid a series of problems caused by unreasonable water spraying; at the same time, in order to improve the deacidification efficiency, the circulating ash concentration needs to be controlled; the establishment of the circulating ash system is closely related to the circulating ash hopper at the bottom of the bag filter; the ash collected by the bag filter enters the circulating ash hopper of the circulating ash system, and the fluidizing chute at the bottom of the circulating ash hopper will return this part of the ash to the reaction tower to form a material circulation to ensure the establishment of the fluidized state in the reaction tower; the return amount of circulating ash is the key to maintaining a stable pressure difference of the fluidized bed in the tower, which is adjusted by the pressure difference of the reaction tower and the flue gas flow rate; due to the large differential pressure of the reaction tower, the amount of the circulating ash hopper needs to be guaranteed, so this optimization adopts the partitioned fluidizing air pressure to remotely control and monitor the ash amount of the circulating ash hopper to ensure the operation of the circulating ash system and improve the stability and purification efficiency of the entire flue gas purification system.

4. A low emission circulating fluidized bed flue gas purification system according to claim 3, characterized in that: The inner wall of the contraction tube (91) has a special spiral texture, so that the smoke can be accelerated more evenly before entering the mixed flow throat (92), thereby reducing the generation of local turbulence. A flow regulating device is provided at the inlet of the contraction tube (91), and the device can automatically adjust the opening of the inlet according to the smoke flow entering the venturi dust collector (9), so as to ensure that the incoming smoke flow is stable within a suitable range. The flow regulating device adopts a high-precision sensor and an intelligent control system, which can monitor the smoke flow in real time and make rapid adjustments when the flow exceeds a set range. The shrink tube (91) is made of a high temperature resistant and corrosion resistant alloy material.

5. A low emission circulating fluidized bed flue gas purification system according to claim 4, characterized in that: The inner wall of the main pipe (923) is coated with a special catalytic coating; the catalytic coating can promote chemical reactions between certain harmful gases in the flue gas and the injected water or other additives; the components of the catalytic coating include a variety of metal oxides and rare earth elements. The opening angle and size of the branch pipe (921) can be adjusted. Through an external adjustment device, the opening state of the branch pipe (921) can be accurately adjusted according to different flue gas components and purification requirements, thereby controlling the flow rate and mixing ratio of materials entering the confluence channel (922); the V-shaped cross-sectional structure of the confluence channel (922) is provided with guide protrusions on the side close to the main pipe (923), and these guide protrusions can further guide the mixed gas and materials to flow more smoothly in the confluence channel (922), thereby avoiding backflow and dead zone phenomena.

6. A low emission circulating fluidized bed flue gas purification system according to claim 5, characterized in that: The inner wall of the diffuser (95) is in a gradually expanding curved shape, so that the smoke gradually slows down and diffuses evenly after flowing out of the mixed flow throat (92); an anti-backflow device is provided at the outlet of the diffuser (95), the device comprising a group of blades, the angle and arrangement of the blades being able to effectively prevent the smoke from flowing back into the diffuser (95); The material of the diffusion tube (95) is a composite material with good thermal insulation performance; A sealing structure with good sealing performance is adopted at the connection portion between the diffuser pipe (95) and the mixed flow throat pipe (92). This sealing structure can prevent smoke leakage and ensure the purification efficiency of the entire Venturi dust collector (9).

7. A low emission circulating fluidized bed flue gas purification system according to claim 6, characterized in that: The inner wall of the reaction tower (3) is provided with a plurality of adsorption layers, the adsorption layers comprising activated carbon fibers and molecular sieves; a stirring device is also provided inside the reaction tower (3), the stirring device comprising a motor, a stirring shaft and stirring blades; a discharge port is provided at the bottom of the reaction tower (3), and an automatic control valve is provided at the discharge port. When the solid waste generated during the adsorption and reaction process reaches a certain amount, the automatic control valve can automatically open to discharge the waste from the reaction tower (3), thereby ensuring the normal operation of the reaction tower (3).

8. A low emission circulating fluidized bed flue gas purification system according to claim 7, characterized in that: The pulse bag filter (4) is provided with a dust cleaning device inside. The dust cleaning device adopts pulse jet technology and can regularly clean the bags. The pressure and frequency of the pulse jet are adjustable. According to the dust content in the flue gas and the clogging condition of the bags, the dust cleaning parameters can be flexibly adjusted to ensure the air permeability and dust removal efficiency of the bags.

9. A low emission circulating fluidized bed flue gas purification system according to claim 8, characterized in that: The flying reservoir (8) is provided with a plurality of partitioned areas inside, and these partitioned areas are used to classify and store different types of pollutants delivered from the venturi dust collector (9) and the pulse bag dust collector (4); each partitioned area is equipped with an independent monitoring system, which can monitor the quantity, composition and state of the pollutants in real time; a ventilation system is provided on the top of the flying reservoir (8), and the ventilation system can maintain air circulation inside the flying reservoir (8) to prevent the accumulation of harmful gases; a liquid discharge port is provided at the bottom of the flying reservoir (8), and when the pollutants contain liquid components, the liquid discharge port can discharge the liquid out of the flying reservoir (8).

10. A low emission circulating fluidized bed flue gas purification system according to claim 9, characterized in that: The water tank (10) is provided with a water level monitoring device inside, which can monitor the water level in the water tank (10) in real time; the water level monitoring device adopts a high-precision sensor, which can accurately feedback water level information; the top of the water tank (10) is provided with a water replenishment port, which is connected to an automatic water replenishment system, and when the water level is lower than a set value, the automatic water replenishment system can automatically replenish water into the water tank (10); the bottom of the water tank (10) is provided with a water outlet, which is connected to a water pump, and the water pump can transport the water in the water tank (10) to the water supply pipe (94) of the Venturi dust collector (9); the outer shell of the water tank (10) adopts a rust-proof material, which can prevent the water tank (10) from rusting and ensure the normal use of the water tank (10); the water tank (10) is also provided with a temperature adjustment device, which can adjust the temperature of the water in the water tank (10) so that the temperature of the water transported to the Venturi dust collector (9) meets the purification requirements.

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