Dust removal device based on granular bed, hot dirty gas deacidification and dust removal system and method

Abstract

This invention discloses a dust removal device, a hot dirty gas deacidification and dust removal system, and a method based on a granular bed. Existing granular bed filters suffer from defects such as numerous dead zones in filter media replacement. The dust removal device of this invention includes a coarse filter tower, a fine filter tower, a filter media tower, a filter cartridge, and a filter media recovery unit. The dust removal system includes a granular bed-based dust removal device, a dust separation device, a filter media silo, and an ejector. In this invention, the filter media tower, fine filter tower, and coarse filter tower are embedded and coaxially arranged, forming an inlet chamber for hot dirty gas and an outlet chamber for hot clean gas. A filter cartridge with an upper cone is concentrically arranged inside the fine filter tower, and the filter cartridge is constructed with a Johnson mesh to form a diffusion chamber. The central filter media is diverted through the filter cartridge to increase its travel, and undergoes two stages of filtration with the hot dirty gas through cross-flow and counter-flow, greatly increasing the dust holding capacity of the central filter media. Furthermore, the entire filter bed moves smoothly downwards, effectively solving the problem of easy fluidization of the bed material in counter-flow granular beds and improving the deacidification and dust removal efficiency.

Description

Technical Field

[0001] This invention belongs to the field of purification and dust removal technology, and in particular relates to a dust removal device and method based on a granular bed, and a hot dirty gas deacidification and dust removal system and deacidification and dust removal method. Background Technology

[0002] Climate change is a global problem facing humanity. Industries such as power, metallurgy, chemical, ceramics, and building materials are exploring technologies for the gasification of bulk solid wastes such as biomass, sludge, municipal solid waste, industrial waste, and organic hazardous waste, coupled with boiler and kiln combustion or deep processing such as hydrogen extraction and synthetic alcohol oil from the gas, to conduct research on carbon emission reduction pathways for various industries.

[0003] Coal grading and quality conversion technology based on low-cost pulverized coal pyrolysis is an important technology for fully utilizing coal resources and ensuring energy security. However, the "four highs" characteristics of the hot, dirty gas produced by the pyrolysis furnace of this technology—high temperature, high dust, high oil content, and high sulfur content—severely restrict its engineering application. Furthermore, producer gas, biomass gas, municipal solid waste gas, and blast furnace gas are also typical examples of hot, dirty gas. Producer gas, in particular, is a low-calorific-value gas produced in a gasifier using coal or coke as gasification feedstock and air and steam as gasifying agents. Typical operating conditions include a temperature of 550℃, an outlet pressure of 1.47–2.45 kPa, and a calorific value of 5110 kJ / m³. 3 The gas composition contains approximately 0.32% H2S and 4.16% C. m H n It contains a relatively high amount of dust, coal powder, and coal tar; blast furnace gas is a byproduct of ironmaking, with typical components of 25% CO, 15% CO2, 55% N2, low H2 and CH4 content, high dust content, and low calorific value of only 3500 kJ / m³. 3 Hot dirty gas, as an inexpensive fuel, can be widely used in gas-fired boilers and other kilns. In my country's energy consumption structure, clean fuels such as refined oil, natural gas, and liquefied petroleum gas are expensive. Therefore, promoting the use of hot dirty gas in enterprises that require gas sources is particularly important for reducing production costs and improving economic efficiency.

[0004] To ensure the normal operation of chemical equipment, gas-fired boilers, coal-fired boilers, and kilns, hot, dirty gas needs to undergo high-temperature purification treatment, such as acid removal and dust removal. After high-temperature desulfurization, dehalogenation, dust removal, and removal of alkali metals to remove harmful substances, the gas can reduce the high and low temperature corrosion of thermal energy equipment by hydrogen chloride and chloride salts, thus broadening the application range of hot, dirty gas. Currently, the technology only involves simple physical dust removal using pipelines, dust hoppers, and centrifugal dust collectors that transport hot, dirty gas. Generally, only dust particles larger than 10μm can be removed, with a dust removal efficiency of only about 75%. However, the technology for acid removal, especially halogen removal, of hot, dirty gas is very lacking. This leads to the need for complex dioxin suppression and removal facilities in the thermal energy combustion equipment of gas utilization units. Furthermore, the fly ash filtered by bag filters has high levels of dioxins, chloride salts, and heavy metals, classifying it as hazardous waste (HW18 incineration residue), which contaminates the fly ash of coupled biomass and coal-fired boilers. Therefore, dehalogenation and dust removal of hot, dirty gas from industrial waste is particularly important.

[0005] A particle bed filter is an industrial high-temperature dust removal device. It uses solid particles with very stable physical and chemical properties to form a filter layer. The dust removal mechanism is reliable. It mainly achieves the capture and purification of solid dust carried in the gas by the filter material through a variety of forces such as direct interception, inertial collision, diffusion deposition, gravity settling and electrostatic attraction. It has the characteristics of high temperature resistance, good durability, not easy to clog and filtration capacity is not affected by resistivity.

[0006] Particle bed filters have good heat resistance and corrosion resistance, making them very suitable for dust removal and filtration of high-temperature corrosive gases, and are expected to achieve integrated acid removal and dust removal of hot and dirty gas. However, existing particle bed filters generally have the following problems: (1) complex structure and high cost; (2) defects in particle fluid dynamics design, with many dead zones in filter media replacement, resulting in no practical use value; (3) system wear problems, which need to be addressed by improving the structure of the dust collector and optimizing the design; (4) the filtration effect deteriorates sharply during the movement of the filter media particle layer, and dust leakage leads to excessive emissions. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing granular bed filters by providing a dust removal device and method based on a granular bed, as well as a hot dirty gas deacidification and dust removal system and method. Powdered deacidifying agent (or granular deacidifying agent with deacidifying activity can be mixed into the filter media) is sprayed into the air inlet pipe connected to the air inlet of the dust removal device. The deacidifying agent reacts with the acidic gas to achieve deacidification. When hot dirty gas passes through the granular bed, the granular bed acts as the filter medium to capture dust, realizing an integrated dry deacidification and dust removal operation, and improving the resource utilization level of hot dirty gas from bulk solid waste.

[0008] This invention is achieved using the following technical solution:

[0009] This invention relates to a dust removal device based on a granular bed, mainly composed of a coarse filter tower, a fine filter tower, a filter media tower, a filter cartridge, and a filter media recovery unit. The coarse filter tower consists of a conical cylindrical body with a central hole on its top cover, which is fixed above the cylindrical body. An air inlet is located on the side wall of the cylindrical body, and a dust-laden filter media outlet is located at the bottom. The fine filter tower, situated above the coarse filter tower, consists of a fine filter cylinder with an open bottom and a fine filter tower top cover with a central hole, which is fixed above the fine filter cylinder. An air outlet is located on the side of the fine filter cylinder. The fine filter cylinder is embedded in the central hole of the coarse filter tower top cover, and its outer side wall matches and is sealed to the central hole of the coarse filter tower top cover. The side wall of the fine filter cylinder, positioned above the coarse filter tower top cover, is connected to the coarse filter tower top cover by two or more tower body adjusting rods. External frame connection; the bottom end face of the fine filter cylinder is set lower than the air inlet of the coarse filter tower; the filter media tower is placed above the fine filter tower and consists of a filter media cylinder with an open bottom and a filter media tower top cover with a central hole, the filter media tower top cover being fixed above the filter media cylinder; the filter media cylinder is embedded in the central hole of the fine filter tower top cover, the outer wall of the filter media cylinder matches the central hole of the fine filter tower top cover and is provided with a sealing structure; the filter media recovery device is placed above the filter media tower; the filter media recovery device has a filter media and airflow mixing inlet, an airflow outlet, and a filter media outlet, the filter media outlet communicating with the central hole of the filter media tower top cover; the filter cartridge is placed inside the fine filter cylinder and suspended at the bottom of the fine filter tower top cover; the filter cartridge, filter media recovery device, filter media cylinder, fine filter cylinder, and coarse filter tower are coaxially arranged.

[0010] Preferably, the filter cartridge includes an integrally formed upper cone, a middle cylinder, and a lower flared section made of Johnson mesh; the middle cylinder is connected to the top cover of the fine filtration tower via two or more filter cartridge adjusting rods.

[0011] Preferably, a rapping device is also provided; the rapping device includes stiffening plates, a vertical impact rod, a horizontal impact rod, and a rapper; two or more stiffening plates are fixed at the middle cylindrical part or the lower flared part of the filter cartridge, evenly distributed circumferentially, and the top of the vertical impact rod is fixed to each stiffening plate; the rapper is fixed to the outer wall of the conical part of the coarse filter tower and to one end of the horizontal impact rod, the horizontal impact rod extends into the body of the coarse filter tower, and the other end contacts the bottom end of the vertical impact rod; a sealing structure is provided between the horizontal impact rod and the body of the coarse filter tower.

[0012] Preferably, the filter media recovery unit, filter media cylinder, fine filter cylinder and coarse filter tower are all provided with a heat insulation layer, and the top cover of the coarse filter tower, the top cover of the fine filter tower and the top cover of the filter media tower are also provided with a heat insulation layer. The temperature inside the dust removal device based on the granular bed is controlled at 400 to 700°C.

[0013] Preferably, the filter media recovery unit is a dry dust collector.

[0014] The dust removal method based on a granular bed dust removal device of the present invention comprises the following specific steps:

[0015] On one hand, the filter media in the filter media recovery unit is mixed with the airflow and fed into the filter media inlet. The clean filter media recovered by the filter media recovery unit flows downward into the filter media tower. The filter media in the filter media tower then flows downward into the fine filter tower, reaching the filter media bed between the inner wall of the fine filter cylinder and the outer wall of the filter cylinder. An air outlet cavity is formed between the outer surface of the filter media bed, the inner wall of the fine filter cylinder, the inner surface of the top cover of the fine filter tower, and the outer wall of the filter media cylinder inserted into the fine filter tower. On the other hand, the dust-laden airflow flows tangentially into the cylinder of the coarse filter tower through the air inlet and is spirally conveyed downward. A portion of the dust-laden airflow bypasses the bottom end of the fine filter cylinder of the fine filter tower and flows upward in a countercurrent direction into the fine filter cylinder, reaching the filter media bed between the fine filter cylinder and the outer wall of the filter cylinder. At this time, the dust carried by the dust-laden airflow is absorbed by the filter media in the filter media bed. The process involves trapping dust to achieve gas-solid separation. The dust-laden filter media, after exiting the fine filter tower, forms a filter media accumulation with inner and outer interfaces. A diffusion cavity is formed between the inner interface of the filter media accumulation and the inner wall of the filter cartridge. An inlet cavity is formed between the outer interface and the inner wall of the coarse filter tower, the inner surface of the coarse filter tower's top cover, and the outer wall of the fine filter cylinder embedded within the coarse filter tower. Another portion of the dust-laden airflow flows cross-currently through the filter media accumulation below the fine filter tower, converging into the diffusion cavity. It diffuses upwards or towards the side wall of the filter cartridge from the inside, and then the dust is trapped by the filter media accumulated around the cartridge, achieving gas-solid separation. The purified gas separated by the dust-laden airflow from the filter media converges into the outlet cavity and is discharged through the outlet of the fine filter tower. The dust-laden filter media is discharged from the dust-laden filter media outlet of the coarse filter tower, completing the dust removal process. The filter media bed movement speed is controlled between 0.1 and 10 cm / min.

[0016] This invention relates to a granular bed-based hot dirty gas deacidification and dust removal system, comprising a granular bed-based dust removal device, a dust separation device, a filter media bin, and an ejector. The inlet of the dust separation device is connected to the dust-laden filter media outlet of the granular bed-based dust removal device. The dust separation device has a granular material outlet and a dust outlet, and the granular material outlet is connected to the inlet of the filter media bin. The inlet of the filter media bin is also connected to a supplementary filter media pipe. The outlet of the filter media bin is connected to the inlet at the throat of the ejector. The gas-solid mixture outlet of the ejector is connected to the filter media and airflow mixing inlet of the granular bed-based dust removal device via a pipeline, and the ejector also has an air inlet.

[0017] Preferably, the dust separation device is a drum screen or a vibrating screen.

[0018] This invention relates to a method for removing acid and dust from hot, dirty fuel gas in a granular bed, as detailed below:

[0019] The granular bed dust collector has an inlet pipe connected to its air inlet. Hot, dirty gas is input through the inlet pipe, and powdered deacidifying agent is simultaneously injected into the inlet pipe. During the mixing and transporting process with the hot, dirty gas, the powdered deacidifying agent removes acidic components from the gas. The dust carried in the dust-laden gas stream after deacidification is trapped by the filter media within the granular bed dust collector, achieving gas-solid separation. The separated clean hot gas is discharged through the outlet of the granular bed dust collector and sent to the gas utilization unit. The dust-laden filter media moves downwards and flows out through the dust-laden filter media outlet of the granular bed dust collector, and is then transported to the dust collection area. The separation device separates dust from the dust outlet and sends it to the ash silo for secondary treatment. The granular material separated by the dust separation device is sent to the filter media bin from the granular material outlet. The supplementary filter media is also added to the filter media bin as filter media for initial start-up and filter media consumption replenishment. The conveying air flows into the air inlet of the ejector, so that the filter media in the filter media bin is sucked in by the negative pressure at the throat of the ejector and lifted into the filter media recovery unit of the dust removal device based on the granular bed. The gas-solid two-phase flow passes through the filter media recovery unit to separate the filter media and exhaust gas. The exhaust gas is discharged through the airflow outlet of the filter media recovery unit and sent to the gas-using unit for reuse.

[0020] Preferably, the filter media is one or more of the following: alumina microspheres, silica, quartz sand, gravel, mullite, coke, metal shavings, ceramics, and ceramsite; the filter media particle size is 0.3–10 mm.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The dust removal device of the present invention is equipped with a filter media recovery device at the top, which realizes the uniform distribution of filter media in the center of the dust removal device and effectively reduces the height of the dust removal device;

[0023] 2. The present invention is equipped with a filter tower, a fine filter tower and a coarse filter tower, and the three towers are stacked vertically and inserted concentrically to form an inlet chamber for hot dirty gas and an outlet chamber for hot clean gas, which is conducive to the uniform distribution of gas flow field and improves the efficiency of acid removal and dust removal.

[0024] 3. To address the challenges of rapid downward movement and low dust holding capacity of the central filter media in granular bed-based dust collectors, and slow downward movement and easy caking of the outer filter media, this invention employs a concentrically arranged filter cylinder with an upper cone within the fine filtration tower. This diversion of the central filter media increases its travel, ensuring that the hot, dirty gas undergoes at least two stages of filtration—cross-flow and counter-flow—significantly increasing the dust holding capacity of the central filter media. Furthermore, the overall downward movement of the filter bed is smooth, enhancing the deacidification and dust removal efficiency of this dust collector. This is beneficial for removing fine dust particles smaller than 1μm, achieving a filtration efficiency of 90%–99%, and controlling the gas dust content to 10–50 mg / Nm³. 3 This meets the needs of downstream gas utilization units;

[0025] 4. A filter cartridge made of Johnson mesh is arranged in the center of the dust removal device of the present invention to form a diffusion chamber. Part of the dust-laden airflow in the inlet chamber flows through the filter media accumulation below the fine filter tower and converges into the diffusion chamber to diffuse upward from the inside of the filter cartridge or towards the side wall of the filter cartridge. The filter media accumulated around the filter cartridge intercepts the dust and achieves gas-solid separation. The filter media bed has low resistance and effectively solves the problem of easy fluidization of the bed material in the countercurrent granular bed.

[0026] 5. The diameter of the air inlet chamber of the dust removal device of the present invention can be set to be larger than the diameter of the air outlet chamber, and the center contains a diffusion chamber. The device structure is conducive to designing a lower filtration velocity for high dust-laden airflow because the device has low resistance and the filter bed has a large dust holding capacity.

[0027] 6. The dust removal device of the present invention is equipped with a vibrator, which transmits the excitation force to the vertical impact rod through the horizontal impact rod, and vibrates the filter cylinder of the hanging structure, loosening the filter material in the dust removal device, so as to realize the smooth downward movement of the filter material bed, stabilize the filtration efficiency, and solve the problem of easy caking and segregation of the bed material in the granular bed.

[0028] 7. The hot dirty gas desulfurization and dust removal system of the present invention discharges the dust-laden filter material from the dust removal device, and then uses a dust separation device to separate the filter material and dust. The separated clean filter material is lifted to the filter material recovery unit for recycling. There is no need to use a back-flushing device, and the system is simple to maintain.

[0029] 8. The fine filter tower and filter cartridge of the present invention are both equipped with lifting and adjustment functions and can be disassembled and replaced as a whole, resulting in low maintenance costs and an annual utilization of over 8,000 hours, ensuring long-term operational reliability and meeting the requirements of various application industries.

[0030] 9. When this invention is applied to the deacidification and dust removal of hot dirty gas, each tower wall and top cover is provided with a heat insulation layer to keep the design temperature of the dust removal device controlled at 400-700℃, and to prevent low-temperature condensation and high-temperature secondary cracking of tar.

[0031] 10. This invention can solve the problem of disposal of chlorine-containing solid waste such as high-chlorine organic industrial solid waste and domestic waste: the purified thermal gas contains extremely low levels of acidic gases such as sulfur, chlorine, and fluorine, as well as dust. The low chlorine and low dust content can effectively inhibit the generation of dioxins in thermal combustion equipment. The purified thermal gas can be used as fuel for gas utilization units such as boilers, hot blast stoves, and kilns, greatly reducing equipment corrosion. If the purified thermal gas is co-fired with other low-chlorine fuels such as coal, general industrial solid waste (such as municipal sludge), and biomass, it can achieve synergistic thermal conversion and clean disposal of multi-source industrial organic solid waste. The resulting ash residue has low chloride and heavy metal content and can be used as a resource for building materials.

[0032] 11. The application scope of this invention is not limited to the purification of hot and dirty gas. It can also be used as a dust removal, desulfurization and dechlorination purification system for blast furnace gas, and can also be used as a substitute for desulfurization towers and bag filters for flue gas deacidification and dust removal. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the dust removal device based on a particle bed according to the present invention.

[0034] Figure 2 This is a flow chart of the hot dirty gas deacidification and dust removal system based on granular bed according to the present invention.

[0035] In the diagram: 1. Coarse filter tower, 2. Rib plate, 3. Diffuser chamber, 4. Vertical impact bar, 5. Dust-laden filter media outlet, 6. Horizontal impact bar, 7. Vibrator, 8. Insulation layer, 9. Air inlet chamber, 10. Air inlet, 11. Top cover of coarse filter tower, 12. Tower body adjusting rod, 13. Fine filter tower, 14. Top cover of fine filter tower, 15. Filter media tower, 16. Top cover of filter media tower, 17. Filter media recovery unit, 18. Filter media and airflow mixing inlet, 19. Airflow outlet, 20. Filter media, 21. Air outlet chamber, 22. Filter cartridge adjusting rod, 23. Air outlet, 24. Filter cartridge, 25. Dust removal device based on granular bed, 26. Dust separation device, 27. Ejector, 28. Filter media bin. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0037] Example 1:

[0038] like Figure 1As shown, the dust removal device 25 based on a granular bed mainly consists of a coarse filter tower 1, a fine filter tower 13, a filter media tower 15, a filter cartridge 24, and a filter media recovery unit 17. The coarse filter tower 1 consists of a cylindrical body with a conical bottom and a coarse filter tower top cover 11 with a central hole, which is fixed above the cylindrical body. An air inlet 10 is provided on the side wall of the cylindrical body, and a dust-laden filter media outlet 5 is provided at the bottom. The fine filter tower 13 is placed above the coarse filter tower 1 and consists of a fine filter cylinder with an open bottom and a fine filter tower top cover with a central hole. The top cover 14 of the fine filter tower is fixed above the fine filter cylinder; an air outlet 23 is opened on the side of the fine filter cylinder; the fine filter cylinder is embedded in the central hole of the top cover 11 of the coarse filter tower, and the outer wall of the fine filter cylinder matches the central hole of the top cover 11 of the coarse filter tower and is provided with a sealing structure; the side wall of the fine filter cylinder is located above the top cover 11 of the coarse filter tower and is connected to the external frame through two or more tower body adjusting rods 12 for adjusting the height of the fine filter tower 13; the bottom end face of the fine filter cylinder is lower than the air inlet 10 of the coarse filter tower 1. The coarse filter tower 1 is constructed as a cyclone separator. A filter media tower 15 is positioned above the fine filter tower 13 and consists of a filter media cylinder with an open bottom and a filter media tower top cover 16 with a central hole. The filter media tower top cover 16 is fixed above the filter media cylinder. The filter media cylinder is embedded in the central hole of the fine filter tower top cover 14, and the outer wall of the filter media cylinder matches the central hole of the fine filter tower top cover 14 and is equipped with a sealing structure. The height of the filter media tower 15 is greater than 500 mm, and this height is specifically determined according to the airtightness requirements. A filter media recovery unit 17 is positioned above the filter media tower 15. The filter media recovery unit 17 has a filter media and airflow mixing inlet 18, an airflow outlet 19, and a filter media outlet, which communicates with the central hole of the filter media tower top cover 16. A filter cylinder 24 is placed inside the fine filter cylinder and suspended from the bottom of the fine filter tower top cover 14. The filter cylinder 24, filter media recovery unit 17, filter media cylinder, fine filter cylinder, and the cylinder body of the coarse filter tower 1 are coaxially arranged. The cylinder of the coarse filter tower 1, the filter media cylinder of the filter media tower 15, and the filter media recovery unit 17 are all fixed to the external frame.

[0039] Preferably, the filter cartridge 24 is a breathable hood, comprising an upper cone, a middle cylinder and a lower flared section, which are integrally formed and made of Johnson mesh; the middle cylinder is connected to the top cover 14 of the fine filtration tower through two or more filter cartridge adjusting rods 22, so that the filter cartridge 24 has a lifting and adjusting function.

[0040] Preferably, the distance between the outer wall of the middle cylinder of the filter cartridge 24 and the inner wall of the fine filter cylinder of the fine filter tower 13 is greater than 50mm. The smaller the distance, the greater the dust holding capacity. The distance also needs to meet the requirement that the filtration flow rate is less than 1m / s, and the commonly used filtration flow rate design is less than 0.3m / s.

[0041] Preferably, to prevent the filter media 20 from clumping or segregating, the present invention provides a rapping device. Specifically, the rapping device includes stiffeners 2, vertical impact rods 4, horizontal impact rods 6, and a vibrator 7. Two or more stiffeners 2 are fixed at the middle cylindrical part or the lower flared part of the filter cylinder 24, which are evenly distributed circumferentially. The top of the vertical impact rods 4 is fixed to each stiffener 2. The vibrator 7 is fixed to the outer wall of the conical part of the coarse filter tower 1 and to one end of the horizontal impact rods 6. The horizontal impact rods 6 extend into the cylinder of the coarse filter tower 1, and the other end contacts the bottom end of the vertical impact rods 4. A sealing structure is provided between the horizontal impact rods 6 and the cylinder of the coarse filter tower 1. The vibrator 7 transmits the excitation force to the vertical impact rods 4 and the filter cylinder 24 through the horizontal impact rods 6, which is used to loosen the filter media 20, so that it moves downward smoothly and the filtration efficiency is more stable.

[0042] Preferably, the filter media recovery unit 17, the filter media cylinder, the fine filter cylinder, and the coarse filter tower 1 are all equipped with a heat insulation layer 8. The top cover 11 of the coarse filter tower, the top cover 14 of the fine filter tower, and the top cover 16 of the filter media tower are also equipped with a heat insulation layer 8. The temperature inside the filter media recovery unit 17, the filter media cylinder, the fine filter cylinder, and the coarse filter tower 1 in this granular bed-based dust removal device 25 is controlled at 400-700℃ to prevent the dust-laden filter media from being too cold and causing tar condensation (tar condensation will affect the separation effect of the dust separation device 26 in the hot dirty gas deacidification and dust removal system based on the granular bed in Example 3, causing the dust removal system to be blocked). However, it is also necessary to prevent the dust-laden filter media from being too hot and causing secondary tar cracking, resulting in severe carbon accumulation on the surface of the filter media 20.

[0043] As a preferred embodiment, the filter media recovery unit 17 is a dry dust collector designed based on the inertial and gravitational effects of dust. It is suitable for the separation or concentration of high-concentration coarse-particle dust. Generally, it is divided into gravity dust collectors, inertial dust collectors (which are further divided into impact dust collectors and reflux dust collectors) and centrifugal dust collectors (which are further divided into single-stage cyclone type, double-stage cyclone type, cast iron multi-tube type, ceramic multi-tube type, etc.). Centrifugal dust collectors are more commonly used for filter media separation and are also the most preferred embodiment of this invention.

[0044] Example 2:

[0045] The dust removal method using the particle bed-based dust removal device described in Example 1 follows these steps:

[0046] On one hand, filter media 20 is input into the filter media and airflow mixing inlet 18 of the filter media recovery unit 17. The clean filter media 20 separated and recovered by the filter media recovery unit 17 flows downward into the filter media tower 15. The filter media 20 in the filter media tower 15 then flows downward into the fine filter tower 13, reaching the filter media bed between the inner wall of the fine filter cylinder and the outer wall of the filter cylinder 24. An air outlet chamber 21 is formed between the outer surface of the filter media bed, the inner wall of the fine filter cylinder, the inner surface of the top cover 14 of the fine filter tower, and the outer wall of the filter media cylinder inserted into the fine filter tower 13. On the other hand, the dust-laden airflow flows tangentially into the cylinder of the coarse filter tower 1 through the air inlet 10 and is spirally conveyed downward. A portion of the dust-laden airflow bypasses the bottom end of the fine filter cylinder of the fine filter tower 13 and flows upward against the flow into the fine filter cylinder, reaching the filter media bed between the fine filter cylinder and the outer wall of the filter cylinder 24. At this time, the dust carried by the dust-laden airflow is absorbed by the filter media 20 in the filter media bed. 0. Gas-solid separation is achieved by interception; the dust-laden filter material formed by the interception of dust by the filter material 20 flows out of the fine filter tower 13 and forms a filter material accumulation with inner and outer interfaces. The inner interface of the filter material accumulation forms a diffusion cavity 3 between the inner wall of the filter cylinder 24 and the outer interface forms an air inlet cavity 9 between the inner wall of the coarse filter tower 1, the inner surface of the top cover 11 of the coarse filter tower, and the outer wall of the fine filter cylinder embedded in the coarse filter tower 1. Another part of the dust-laden airflow cross-flows through the filter material accumulation below the fine filter tower 13 and converges into the diffusion cavity 3. It diffuses upward from the inside of the filter cylinder 24 or towards the side wall of the filter cylinder 24, and then the dust is intercepted by the filter material 20 accumulated around the filter cylinder 24 to achieve gas-solid separation. The purified gas separated by the interception of the dust-laden airflow by the filter material 20 converges into the outlet cavity 21 and is discharged through the outlet 23 of the fine filter tower 13. The dust-laden filter material is discharged from the dust-laden filter material outlet 5 of the coarse filter tower 1, completing the dust removal of the dust-laden airflow. As the dust holding capacity of the filter media increases, the dust continuously fills the gaps between the filter media, causing an increase in the pressure of the filter media bed. Therefore, the dust-laden filter media needs to be continuously or intermittently discharged from the dust-laden filter media outlet 5 of the coarse filter tower 1. The moving speed of the filter media bed should be controlled between 0.1 and 10 cm / min to meet the requirements of the purification efficiency and filtration pressure drop ΔP < 2500 Pa (set value, adjustable) of the dust removal device 25 of the present invention.

[0047] When the filter media (particles) in the filter media tower 15 flows into the fine filter tower 13, the filter media near the center of the filter media cylinder first touches the upper cone of the filter cylinder 24 and is diverted, flowing into the middle cylinder and the lower flared part of the filter cylinder 24. Due to the inherent angle of repose of the filter media (generally, the angle of repose of the filter media is less than 35°), an inverted frustum is naturally formed (this invention is described as a dust removal device 25 based on a particle bed with a circular cross-section, but the cross-section structure can naturally also be designed as a polygon), thereby forming a filter media bed between the fine filter cylinder and the outer wall of the filter cylinder 24. The distance between the bottom of the diffusion chamber 3 and the dust-laden filter media outlet 5 should be designed to be greater than 500mm. This height is determined based on the airtightness requirements of the dust removal device 25 based on the particle bed of the present invention. The cone angle of the upper cone of the filter cylinder 24 is also designed with reference to the angle of repose of the filter media 20. The thickness of the filter media bed layer on the surface of the upper cone should be designed to be greater than 50mm. The greater the thickness, the higher the purification efficiency of the dust removal device 25 of the present invention, and the greater the resistance, and vice versa. The depth to which the filter media tower 15 is inserted into the fine filter tower 13 must ensure that the edge line of the filter media 20 in contact with the inner wall of the fine filter tower 13 is lower than the lower edge of the air outlet 23 of the fine filter tower 13, so as to ensure that the filter media 20 will not block the air outlet 23. The greater the distance between the edge line of the filter media in contact with the inner wall of the fine filter tower 13 and the bottom end face of the fine filter tower 13, the higher the purification efficiency of the dust removal device 25 of the present invention and the greater the resistance, and vice versa. The specific distance depends on the purification efficiency and resistance requirements, and is generally designed to be 100-150mm, which can basically meet the requirements of acid removal and dust removal.

[0048] Example 3:

[0049] like Figure 2 As shown, the hot dirty gas desulfurization and dust removal system based on a granular bed includes a granular bed-based dust removal device 25, a dust separation device 26, a filter media bin 28, and an ejector 27, as described in Example 1. The inlet of the dust separation device 26 is connected to the dust-laden filter media outlet of the granular bed-based dust removal device 25. The dust separation device 26 has a granular material outlet and a dust outlet, and the granular material outlet is connected to the inlet of the filter media bin 28. The inlet of the filter media bin 28 is also connected to a supplementary filter media pipe C for supplementing filter media. The outlet of the filter media bin 28 is connected to the inlet at the throat of the ejector 27. The gas-solid mixture outlet of the ejector 27 is connected to the filter media and airflow mixing inlet 18 of the granular bed-based dust removal device 25 through a pipeline. The ejector 27 is also provided with an air inlet.

[0050] Preferably, the ejector 27 adopts a venturi tube structure; the ejector 27 can use an air pump to input and deliver air E.

[0051] Preferably, the dust separation device 26 is a drum screen or a vibrating screen.

[0052] Among them, the filter media bin 28, the ejector 27 and the filter media recycler 17 constitute the filter media 20 return device. The return device can also be implemented by other mechanical conveying and lifting devices, which does not affect the deacidification and dust removal applicability of the dust removal device 25 based on the granular bed in this invention.

[0053] Example 4:

[0054] The method for removing acid and dust from hot, dirty gas based on granular bed is as follows:

[0055] The inlet 10 of the granular bed dust collector 25 is connected to an inlet pipe. Hot dirty gas A is input through the inlet pipe, and powdered deacidifying agent G is simultaneously injected into the inlet pipe. During the mixing and conveying process with hot dirty gas A, the powdered deacidifying agent G removes the acidic components in the hot dirty gas A. The dust carried in the dust-laden gas flow after the hot dirty gas A is deacidified is intercepted by the filter media 20 in the granular bed dust collector 25 to achieve gas-solid separation. The separated hot clean gas B is discharged through the outlet 23 of the granular bed dust collector 25 and sent to the gas utilization unit for use. The dust-laden filter media moves down and flows out through the dust-laden filter media outlet 5 of the granular bed dust collector 25 and is conveyed to the dust separation device 26. Dust D separated by dust separation device 26 is sent to ash silo for secondary treatment from dust outlet; granular material separated by dust separation device 26 is sent to filter media bin 28 from granular material outlet, and supplementary filter media is also added to filter media bin 28 as filter media for initial start-up and filter media consumption replenishment; conveying air E flows into the air inlet of ejector 27 at high speed, so that the filter media in filter media bin 28 is continuously sucked in by negative pressure at the throat of ejector 27 and lifted into the filter media recovery unit 17 of dust removal device 25 based on granular bed. The gas-solid two-phase flow passes through filter media recovery unit 17 to separate filter media 20 and exhaust gas F. Exhaust gas F is discharged through airflow outlet 19 of filter media recovery unit 17 and sent to air-using unit for reuse.

[0056] Preferably, the powdered deacidifying agent G can be a calcium-based, sodium-based, magnesium-based, or amino-based deacidifying agent commonly used in the gas purification and flue gas purification industries, such as Ca(OH)2, CaO, NaOH, Na2CO3, NaHCO3, Mg(OH)2, MgO, and NH3. The amount of powdered deacidifying agent G used is determined according to the set deacidification efficiency test. Generally, the Ca / S ratio or Ca / 2Cl ratio should be controlled between 1 and 3. The specific Ca / S ratio or Ca / 2Cl ratio is selected based on the main target component (S or Cl) to be deacidified. As another optional embodiment of the present invention, the powdered deacidifying agent G can be directly mixed into the filter media 20 instead of being sprayed into the air inlet pipe connected to the air inlet 10.

[0057] Preferably, the filter media 20 is a granular material, such as alumina spheres, silica, quartz sand, gravel, mullite, coke, metal shavings, ceramics, ceramsite, etc., or it can be a mixture of multiple materials; the particle size of the filter media 20 is 0.3 to 10 mm, and the commonly used particle size is 2 to 5 mm. The smaller the particle size, the higher the dust removal efficiency and the greater the resistance of the device.

[0058] The following are two typical examples of actual production, which include specific parameter values ​​and specific components.

[0059] Example 5: Acid removal and dust removal method based on hot dirty gas from granular bed, wherein the hot dirty gas is municipal solid waste gasification gas, the gas temperature is controlled at 450±50℃, and the gas flow rate is controlled at 43000~53000 Nm³. 3 / h, initial dust content 30g / Nm 3 The filter media bed thickness on the upper conical surface of filter cartridge 24 is 100mm. The filter media uses alumina with a particle size controlled between 3mm and 6mm. The filtration velocity of the hot, dirty gas is controlled between 0.3 and 0.5m / s, and the filtration pressure drop is less than 1700Pa (adjustable). The total dust removal efficiency (purification efficiency) can reach 95% to 99.99%, and the dust content of the hot, clean gas is less than 50mg / Nm³. 3 The powdered deacidifying agent uses CaO, Ca / 2Cl = 2, with a dechlorination efficiency of 90% and a desulfurization efficiency of 85%.

[0060] Example 6: Acid removal and dust removal method based on hot dirty gas from granular bed, wherein the hot dirty gas is industrial waste gasification gas, the gas temperature is controlled at 650±50℃, and the gas flow rate is controlled at 2200~2600Nm³. 3 / h, initial dust content controlled at 50~100g / Nm 3 The thickness of the filter bed on the upper cone surface is 150mm. The filter media is quartz sand with a particle size controlled between 1.5 and 3mm. The filtration velocity of the hot, dirty gas is controlled between 0.1 and 0.3 m / s, and the filtration pressure drop is less than 2000 Pa (adjustable). The total dust removal efficiency can reach 98% to 99.99%, and the dust content of the cleaned hot gas is less than 10 mg / Nm³. 3 The powdered deacidifying agent uses Ca(OH)2, Ca / 2Cl = 1.5, with a dechlorination efficiency of 94.6% and a desulfurization efficiency of 90%.

[0061] The above-described embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above-described embodiments. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essential content of the present invention shall fall within the protection scope of the present invention.

Claims

1. A dust removal device based on a granular bed, comprising a coarse filter tower, a filter media tower, and a filter media recovery unit, characterized in that: It also includes a fine filter tower and a filter cartridge; the coarse filter tower consists of a cylindrical body with a conical bottom and a top cover with a central hole, the top cover being fixed above the cylindrical body; an air inlet is provided on the side wall of the cylindrical body, and a dust-laden filter media outlet is provided at the bottom; the fine filter tower is placed above the coarse filter tower and consists of a fine filter cylinder with an open bottom and a top cover with a central hole, the top cover being fixed above the fine filter cylinder; an air outlet is provided on the side of the fine filter cylinder; the fine filter cylinder is embedded in the central hole of the top cover of the coarse filter tower, the outer side wall of the fine filter cylinder matches the central hole of the top cover of the coarse filter tower and is equipped with a sealing structure; the side wall of the fine filter cylinder, located above the top cover of the coarse filter tower, is connected to the external frame via two or more tower body adjusting rods; the bottom end face of the fine filter cylinder... The filter media tower is positioned below the air inlet of the coarse filter tower. It is located above the fine filter tower and consists of a filter media cylinder with an open bottom and a filter media tower top cover with a central hole. The top cover is fixed above the filter media cylinder. The filter media cylinder is embedded in the central hole of the fine filter tower top cover, and the outer wall of the filter media cylinder matches the central hole of the fine filter tower top cover and is equipped with a sealing structure. A filter media recovery unit is located above the filter tower. The filter media recovery unit has a filter media and airflow mixing inlet, an airflow outlet, and a filter media outlet. The filter media outlet communicates with the central hole of the filter tower top cover. The filter cartridge is placed inside the fine filter cylinder and suspended from the bottom of the fine filter tower top cover. The filter cartridge, filter media recovery unit, filter media cylinder, fine filter cylinder, and the cylinder body of the coarse filter tower are coaxially arranged. The filter cartridge includes an integrally formed upper cone, a middle cylinder, and a lower flared section made of Johnson mesh; the middle cylinder is connected to the top cover of the fine filtration tower via two or more filter cartridge adjusting rods.

2. The dust removal device based on a granular bed according to claim 1, characterized in that: A rapping device is also provided; the rapping device includes stiffening plates, a vertical impact rod, a horizontal impact rod, and a rapper; two or more stiffening plates are fixed in the middle cylindrical part or the lower flared part of the filter cartridge, evenly distributed around the circumference; the top of the vertical impact rod is fixed to each stiffening plate; the rapper is fixed to the outer wall of the conical part of the coarse filter tower and to one end of the horizontal impact rod, the horizontal impact rod extends into the body of the coarse filter tower, and the other end contacts the bottom end of the vertical impact rod; a sealing structure is provided between the horizontal impact rod and the body of the coarse filter tower.

3. The dust removal device based on a particle bed according to claim 1 or 2, characterized in that: The filter media recovery unit, filter media cylinder, fine filter cylinder and coarse filter tower are all equipped with a heat insulation layer. The top cover of the coarse filter tower, the top cover of the fine filter tower and the top cover of the filter media tower are also equipped with a heat insulation layer. The temperature inside the dust removal device based on the granular bed is controlled at 400-700℃.

4. The dust removal device based on a granular bed according to claim 1 or 2, characterized in that: The filter media recovery unit is a dry dust collector.

5. A method for dust removal using the particle bed-based dust removal device as described in claim 1 or 2, characterized in that: The specific steps of this method are as follows: On one hand, the filter media in the filter media recovery unit is mixed with the airflow and fed into the filter media inlet. The clean filter media recovered by the filter media recovery unit flows downward into the filter media tower, and the filter media in the filter media tower then flows downward into the fine filter tower, reaching the inner wall of the fine filter cylinder and the outer wall of the filter cylinder to form a filter media bed. An air outlet cavity is formed between the outer surface of the filter media bed, the inner wall of the fine filter cylinder, the inner surface of the top cover of the fine filter tower, and the outer wall of the filter media cylinder inserted into the fine filter tower. On the other hand, the dust-laden airflow flows tangentially into the cylinder of the coarse filter tower through the air inlet and is spirally conveyed downward. A portion of the dust-laden airflow bypasses the bottom end of the fine filter cylinder of the fine filter tower and flows upward in a countercurrent direction into the fine filter cylinder, reaching the filter media bed between the fine filter cylinder and the outer wall of the filter cylinder. At this time, the dust carried by the dust-laden airflow is intercepted by the filter media in the filter media bed, achieving gas-solid separation. The filter media intercepts the dust. After the dust-laden filter media flows out of the fine filter tower, it forms a filter media accumulation with inner and outer interfaces. The inner interface of the filter media accumulation forms a diffusion cavity between itself and the inner wall of the filter cylinder, while the outer interface forms an air inlet cavity between itself and the inner wall of the coarse filter tower, the inner surface of the top cover of the coarse filter tower, and the outer wall of the fine filter cylinder embedded in the coarse filter tower. Another part of the dust-laden airflow flows through the filter media accumulation below the fine filter tower and converges into the diffusion cavity. It diffuses upward from the inside of the filter cylinder or towards the side wall of the filter cylinder, and then the dust is intercepted by the filter media accumulated around the filter cylinder to achieve gas-solid separation. The purified gas separated by the dust-laden airflow through the filter media converges into the outlet cavity and is then discharged through the outlet of the fine filter tower. The dust-laden filter media is discharged from the dust-laden filter media outlet of the coarse filter tower, completing the dust removal of the dust-laden airflow. The moving speed of the filter media bed is controlled between 0.1 and 10 cm / min.

6. A hot, dirty gas desulfurization and dust removal system using the granular bed-based dust removal device as described in claim 1 or 2, characterized in that: The device includes a granular bed-based dust collector, a dust separation device, a filter media bin, and an ejector. The inlet of the dust separation device is connected to the dust-laden filter media outlet of the granular bed-based dust collector. The dust separation device has a granular material outlet and a dust outlet, and the granular material outlet is connected to the inlet of the filter media bin. The inlet of the filter media bin is also connected to a supplementary filter media pipe. The outlet of the filter media bin is connected to the inlet at the throat of the ejector. The gas-solid mixture outlet of the ejector is connected to the filter media and airflow mixing inlet of the granular bed-based dust collector via a pipeline. The ejector also has an air inlet.

7. The hot dirty gas desulfurization and dust removal system using a granular bed-based dust removal device according to claim 6, characterized in that: The dust separation device mentioned above is a drum screen or a vibrating screen.

8. The method for removing acid from hot dirty gas using a hot dirty gas desulfurization and dust removal system based on a granular bed dust removal device according to claim 6, characterized in that: The method is as follows: The dust removal device based on the granular bed is connected to an air inlet pipe. Hot dirty gas is input through the air inlet pipe, and powdered deacidifying agent is sprayed into the air inlet pipe at the same time. The powdered deacidifying agent removes the acidic components in the hot dirty gas during the mixing and transportation process with the hot dirty gas. Dust carried in the dust-laden airflow after the deacidification of hot, dirty fuel gas is trapped by the filter media in the granular bed dust collector, achieving gas-solid separation. The separated hot, clean fuel gas is discharged through the outlet of the granular bed dust collector and sent to the fuel gas utilization unit for use. The dust-laden filter media moves downward and flows out through the dust-laden filter media outlet of the granular bed dust collector, and is then transported to the dust separation device. The dust separated by the dust separation device is sent from the dust outlet to the ash silo for secondary treatment. The granular material separated by the dust separation device is sent from the granular material outlet to the filter media bin, and the replenished filter media is also added to the filter media bin as initial start-up filter media and filter media consumption replenishment. The conveying air flows into the air inlet of the ejector, causing the filter media in the filter media bin to be sucked in by the negative pressure at the throat of the ejector and lifted into the filter media recovery unit of the granular bed dust collector. The gas-solid two-phase flow passes through the filter media recovery unit to separate the filter media and exhaust gas. The exhaust gas is discharged through the airflow outlet of the filter media recovery unit and sent to the gas utilization unit for reuse.

9. The method for removing acid from hot dirty gas using a hot dirty gas desulfurization and dust removal system based on a granular bed dust removal device according to claim 8, characterized in that: The filter media is made of one or more of the following: alumina microspheres, silica, quartz sand, gravel, mullite, coke, metal shavings, ceramics, and ceramsite; the particle size of the filter media is 0.3–10 mm.

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