Steel rolling heating furnace ceramic fiber filter tube desulfurization, denitrification and dust removal collaborative treatment system

Abstract

The invention discloses a steel rolling heating furnace ceramic fiber filter tube desulfurization, denitrification and dust removal collaborative treatment system. Comprising a heat exchanger (1), a dry desulfurization reactor (2), a dust and nitrate integrated device (5) and a waste heat utilization device (6), the inlet end of the dry desulfurization reactor (2) is connected with a desulfurization spraying device from the air classification grinding machine (13), and the outlet end of the dry desulfurization reactor (2) is connected with the ammonia spraying section (3); the ammonia spraying section (3) is connected with the protective agent spraying section (4); an outlet of the protective agent spraying section (4) is connected with the dust and nitrate integrated device (5); the dust and nitrate integrated device (5) comprises a dust hopper, a middle box body, an upper box body and a gas purification chamber; and a catalyst ceramic fiber filter tube is arranged in the middle box body and is arranged in different chambers. The invention belongs to a full-dry process, and has the advantages of no secondary pollution of wastewater, simple system, convenience in maintenance and management, less required fixed staff, no white smoke phenomenon, no equipment corrosion problem and no need of antiseptic treatment of the system and the chimney.

Description

Technical Field

[0001] The present invention belongs to the technical field of air pollutant control, and in particular relates to a collaborative desulfurization, denitrification and dust removal control system for a steel rolling heating furnace using ceramic fiber filter tubes. Background Art

[0002] The pollutants emitted by the steel rolling heating furnace are natural gas, blast furnace gas, etc. The flue gas produced after combustion has a flue gas temperature of 350~400℃ after the flue heat exchanger, SO2, NO X The high content, small particle size and large fluctuations in operating conditions have caused serious damage to the environment due to the emission of these pollutants.

[0003] The main process used for flue gas denitrification is the SCR denitrification process route, the main processes used for desulfurization are calcium agent fixed bed, moving bed, and SDS desulfurization, and dust removal is mainly bag dust removal; it has problems such as long process flow, complex system and equipment configuration, large footprint, large system resistance, high energy consumption, and high failure rate.

[0004] Ceramic fiber filter tubes have the advantages of good temperature resistance, synergistic denitrification and dust removal functions, long service life, high denitrification and dust removal efficiency, low resistance (total equipment resistance is less than 1200 Pa), and low operating cost.

[0005] At present, my country still lacks the particulate matter, SO2, NO X Regarding collaborative governance technology and equipment, there is no application case of using ceramic fiber filter tubes for collaborative desulfurization, denitrification and dust removal in steel rolling heating furnaces at home and abroad. Summary of the invention

[0006] The purpose of the present invention is to provide a steel rolling heating furnace ceramic fiber filter tube desulfurization, denitrification and dust removal coordinated treatment system to overcome the shortcomings of the prior art.

[0007] The technical solution of the present invention is: a steel rolling heating furnace ceramic fiber filter tube desulfurization, denitrification and dust removal coordinated treatment system, including a dry desulfurization reactor, a dust and nitrate integrated device, and a waste heat utilization device; the inlet end of the dry desulfurization reactor is connected to an air classification grinder, and the outlet end is connected to an ammonia spraying section; the outlet of the ammonia spraying section is connected to the waste heat utilization device, and the outlet of the protective agent injection section is connected to the dust and nitrate integrated device; the dust and nitrate integrated device includes an ash hopper, a middle box, an upper box, and a clean air chamber; a catalytic ceramic fiber filter tube is arranged in a compartment in the middle box, and a flower plate and a pressing device are also arranged in the middle box, and the flower plate is provided with flower plate holes, and the number of the flower plate holes is consistent with the number of the ceramic filter cartridges, one-to-one corresponding; the upper end of the ceramic filter cartridge is open, and the upper end of the ceramic filter cartridge is sealed and connected to the corresponding upper flower plate hole; the pressing device is provided with openings, and the number of openings is consistent with the number of the catalytic ceramic fiber filter tubes, one-to-one corresponding; the waste heat utilization device is connected to the chimney through an induced draft fan.

[0008] Furthermore, the air-classifying grinder is connected to a desulfurizing agent bin, and a metering and mixing device is provided between the air-classifying grinder and the desulfurizing agent bin.

[0009] Furthermore, the ammonia spraying section is connected to an ammonia water station, and the protective agent spraying section is connected to a protective agent bin.

[0010] Furthermore, the inlet of the dry desulfurization reactor is connected to an induced draft fan system, and the induced draft fan system includes a high-temperature induced draft fan and a cooling system.

[0011] Furthermore, the ammonia spraying section includes an ammonia water tank, an ammonia water vaporizer, an ammonia water dilution fan, an ammonia water metering and mixing module, and a spray device.

[0012] Furthermore, the ash hopper is connected to an ash conveying system, and the ash conveying system is provided with an ash conveying bin pump, a collecting ash bin, an ash conveying pipeline, and an ash conveying valve.

[0013] Furthermore, an anti-sway device is provided between the clamping device and the flower plate, and a short tube is installed between the clamping device and the flower plate.

[0014] Furthermore, the cylinder wall of the catalytic ceramic fiber filter tube includes a dust removal layer and a denitration layer from the outside to the inside; the dust removal layer is a ceramic fiber layer, and the denitration layer is a ceramic fiber layer with a denitration catalyst attached.

[0015] Furthermore, the dry desulfurization reactor, the dust and nitrate integrated device, and the waste heat utilization device are connected to an electronic control system.

[0016] Furthermore, the electric control system is a DCS or PLC control system.

[0017] The waste heat utilization device is a waste heat recovery boiler.

[0018] The system is equipped with two bypasses. The first bypass can bypass the catalyst ceramic fiber filter tube dust and nitrate integrated system and directly enter the waste heat recovery boiler. The second bypass can directly enter the chimney through the induced draft fan when the waste heat recovery system is under maintenance. The bypass system is only used temporarily when two devices are damaged and under maintenance in special circumstances. The bypass is controlled by the corresponding valve.

[0019] The workflow includes the following steps: The heat exchanger system cools the flue gas to the design temperature; After cooling, the flue gas is desulfurized by spraying desulfurizer into the pipeline; After desulfurization, the flue gas is sprayed with ammonia in the pipeline; After ammonia spraying, the flue gas enters the catalyst ceramic biofiber filter tube dust and nitrate integrated system for denitrification and dust removal; Recover waste heat from flue gas that meets the standards; The ash conveying system collects and transports the dust; The induced draft fan system introduces the flue gas after waste heat recovery into the chimney emission, electronic control system, storage system and chimney system.

[0020] The beneficial technical effects of the present invention are: achieving coordinated management of short-process desulfurization, denitrification and dust removal, high equipment integration, smaller equipment size under the same power, reducing the number of system equipment, saving floor space, reducing equipment investment and operating costs; the biosoluble fiber ceramic filter tube has good temperature resistance, high porosity, is not easy to be blocked, is easy to clean, has a long service life, stable performance, high denitrification and dust removal efficiency, can be stably operated in compliance with standards for a long period of time, is economical and efficient, reduces material consumption, has obvious advantages in energy saving and consumption reduction, and has significant environmental benefits; it is a fully dry process, does not produce secondary pollution of wastewater, has a simple system, is easy to maintain and manage, requires fewer staff, has no "white smoke" phenomenon, no equipment corrosion problems, and the system and chimney do not require anti-corrosion treatment and other advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the structural diagram of the ceramic fiber filter tube desulfurization, denitrification and dust removal coordinated treatment system for the steel rolling heating furnace.

[0022] In the figure: 1-heat exchanger, 2-dry desulfurization reactor, 3-ammonia injection section, 4-protective agent injection section, 5-dust and nitrate integrated device, 6-waste heat utilization device, 7-induced draft fan, 8-chimney, 9-ammonia water station, 10-protective agent warehouse, 11-desulfurization agent warehouse, 12-metering and mixing device, 13-air classification grinder. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0025] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0026] like Figure 1As shown, the steel rolling heating furnace ceramic fiber filter tube desulfurization, denitrification and dust removal coordinated treatment system includes a heat exchanger 1, a dry desulfurization reactor 2, a dust and nitrate integrated device 5, and a waste heat utilization device 6; the inlet end of the dry desulfurization reactor 2 is connected to an air classification grinder 13, and the outlet end is connected to an ammonia injection section 2; the ammonia injection section 3 is connected to a protective agent injection section 4, and the outlet of the protective agent injection section 4 is connected to the dust and nitrate integrated device 5; the dust and nitrate integrated device 5 includes an ash hopper, a middle box, an upper box, and a clean air chamber; a catalyst ceramic fiber is arranged in the middle box The filter tube, the catalytic ceramic fiber filter tube is arranged in a compartment, and a flower plate and a pressing device are also arranged in the middle box body. The flower plate is provided with flower plate holes, and the number of the flower plate holes is consistent with the number of the ceramic filter cartridges, one-to-one corresponding; the upper end of the ceramic filter cartridge is open, and the upper end of the ceramic filter cartridge is sealed and connected with the corresponding upper flower plate holes; the pressing device is provided with openings, and the number of the openings is consistent with the number of the catalytic ceramic fiber filter tubes, one-to-one corresponding; the waste heat utilization device 6 is connected to the chimney 8 through the induced draft fan 7.

[0027] The air classification grinder 13 is connected to the desulfurization agent bin 11 , and a metering and mixing device 12 is arranged between the air classification grinder 13 and the desulfurization agent bin 11 .

[0028] The ammonia spraying section 2 is connected to an ammonia water station 9 , and the protective agent spraying section 4 is connected to a protective agent bin 10 .

[0029] The outlet of the dust and saltpeter integrated device 5 is connected to a waste heat utilization device 6, and the induced draft fan system 7 includes a high-temperature induced draft fan and a cooling system.

[0030] The ammonia spraying section 2 comprises an ammonia water tank, an ammonia water vaporizer, an ammonia water dilution fan, an ammonia water metering and mixing module, and a spray device.

[0031] The ash hopper is connected to the ash conveying system, and the ash conveying system is provided with an ash conveying bin pump, a collecting ash bin, an ash conveying pipeline, and an ash conveying valve.

[0032] The clamping device and the flower plate are provided with anti-swaying devices, and a short tube is installed between the clamping device and the flower plate.

[0033] The wall of the catalyst ceramic fiber filter tube includes a dust removal layer and a denitration layer from the outside to the inside; the dust removal layer is composed of ceramic fibers, and the denitration catalyst is evenly attached to the surface of the ceramic fibers; different catalyst formulas can be selected for different flue gas types. The catalyst can be selected from low-temperature, medium-temperature and high-temperature catalysts, which are selected according to different flue gas characteristics and treatment efficiency, and are widely used.

[0034] The dry desulfurization reactor 2, the dust and saltpeter integrated device 5, and the waste heat utilization device 6 are connected to the electric control system.

[0035] The electronic control system is a DCS or PLC control system, and the signals of temperature, pressure, liquid level, flow, PH, oxygen content, concentration detection and CEMS in the system are all connected to the DCS or PLC control system.

[0036] The ceramic fiber filter tubes are arranged in compartments and have an online maintenance function.

[0037] The desulfurizer supply system has a precise online adjustment function, which can automatically and accurately control the outlet SO2 emission concentration in a timely manner, adjust the injection amount of desulfurizer ultrafine powder, and reduce consumption while meeting emission standards.

[0038] The design of the ceramic fiber filter cartridge integrated dust collector needs to consider the displacement caused by temperature resistance and thermal expansion; the catalyst ceramic bio-fiber filter tube dust and saltpeter integrated system is provided with a flower plate and a clamping device in the box body; the flower plate is provided with flower plate holes, and the number of the flower plate holes is consistent with the number of the ceramic filter cartridges, one-to-one corresponding; the upper end of the ceramic filter cartridge is open, and the upper end of the ceramic filter cartridge is sealed and connected with the corresponding upper flower plate holes; the clamping device is provided with openings, and the number of the openings is consistent with the number of the ceramic filter cartridges, one-to-one corresponding; the clamping device and the flower plate are provided with anti-sway measures, and the sealing surface adopts flexible sealing, leaving a margin for thermal expansion, and the short tube measure is adopted to prevent the filter tube from breaking under the premise of ensuring sealing.

[0039] The system workflow includes the following steps: the flue gas of the heating furnace is drawn out from the original flue with a temperature of about 350~400℃. Considering the applicable temperature of baking soda desulfurization, reducing equipment investment and waste heat utilization, the flue gas temperature is reduced to ~240℃ through the heat exchanger; through the draft fan, it enters the ceramic fiber filter tube desulfurization, denitrification and dust removal coordinated management technology and equipment system of the steel rolling heating furnace. Ultrafine baking soda powder ground by the mill is sprayed into the flue before the entrance of the catalyst ceramic biofiber filter tube dust and nitrate integrated system. The desulfurization products and dust in the flue gas enter the catalyst ceramic biofiber filter tube dust and nitrate integrated system together with the flue gas for filtration, denitrification and dust removal. The purified flue gas collects the waste heat through the waste heat recovery system and then is discharged through the chimney to meet the standards. The desulfurization and denitrification products and dust are collected in the desulfurization ash bin and transported out for comprehensive utilization. The recovered heat source has obvious advantages in energy saving and consumption reduction, and has significant environmental and economic benefits. After running for a period of time, the inlet temperature of the dust and nitrate integrated equipment can be increased to ~320℃ by adjusting the load of the heat exchanger to regenerate the catalytic ceramic biofiber filter tube, and the ammonium sulfate and ammonium sulfate loaded on the fiber tube are used for decomposition to improve the denitration efficiency of the fiber tube and reduce the resistance of the dust and nitrate integrated equipment. When the steel rolling heating furnace is started or under low load, causing the flue gas temperature to be below the dew point, the protective agent injection device is automatically turned on to spray the ceramic fiber filter tube protective agent (the protective agent can be lime) to protect the ceramic fiber filter tube, preventing the moisture in the flue gas from damaging the ceramic fiber filter tube, causing problems such as reduced service life and broken tubes.

[0040] Optionally, during the heating process of the denitrification and dust removal system, in order to prevent the formation of condensed water on the surface of the ceramic filter cartridge, the heating rate cannot be lower than 5-10℃ / min when the system temperature is within 120℃, and the heating rate can be based on the actual working conditions when the system temperature is above 120℃.

[0041] Optionally, ammonia can be sprayed into the system only after the temperature in the denitrification and dust removal device reaches 240°C, otherwise ammonia spraying is prohibited.

[0042] Optionally, monitor the composition of the purified flue gas. If the NOx content is too high, gradually increase the amount of ammonia sprayed, and monitor the data again after each increase has stabilized for 2 hours.

[0043] Optionally, monitor the composition of the purified flue gas. If the SO2 content is too high, gradually increase the amount of desulfurizer, and monitor the data again after each increase in dosage stabilizes for 1 hour. First, ensure that the SO2 content is not higher than 50 mg / Nm 3 .

[0044] .Optionally, according to the operating time or warehouse pressure, the backflush cleaning system can be turned on in time, and the operation of each backflush pipe can be inspected one by one to implement the backflush control requirements.

[0045] Optionally, during normal operation of the system, regularly record the temperature, pressure difference, backwash pressure and flue gas data. If the flue gas temperature and pressure difference change significantly, make corresponding adjustments according to the operating requirements.

[0046] This system can remove pollutants such as SO2, NOx, dioxins, ultrafine dust particles, HCL, HF, etc. from flue gas while meeting the current new environmental protection standards. It has the advantages of no wastewater discharge and no chimney rain in the exhaust flue gas. It has the advantages of simple process, small footprint, good high temperature resistance, strong corrosion resistance, low operating cost, simple maintenance, long service life, obvious economic and environmental benefits, etc. It can replace traditional filter bag dust removal.

[0047] This system can be used as a new project. At the same time, this system can be used to transform the original steel rolling heating furnace desulfurization project and upgrade the existing project. It can realize dynamic adjustment and control functions at a relatively low cost, and achieve the purpose of energy saving and reducing operating costs.

[0048] The implementation scheme described above in conjunction with the drawings is only a preferred embodiment of the present invention. The present invention is not limited to the specific details in the above-mentioned scheme. Any modification or replacement made under the concept and principle of the present invention is within the protection scope of the present invention.

Claims

1. The desulfurization, denitrification and dust removal coordinated treatment system of the ceramic fiber filter tube of the steel rolling heating furnace is characterized by: The invention comprises a dry desulfurization reactor (2), a dust and nitrate integrated device (5), and a waste heat utilization device (6); the inlet end of the dry desulfurization reactor (2) is connected to an air classification grinder (13), and the outlet end is connected to an ammonia spraying section (3); the ammonia spraying section (3) is connected to a protective agent spraying section (4), and the outlet of the protective agent spraying section (4) is connected to the dust and nitrate integrated device (5); the dust and nitrate integrated device (5) comprises an ash hopper, a middle box, an upper box, and a clean air chamber; a catalyst ceramic fiber filter tube is arranged in the middle box, and the catalyst The ceramic fiber filter tubes are arranged in compartments, and the middle box body is also provided with a flower plate and a pressing device. The flower plate is provided with flower plate holes, and the number of the flower plate holes is consistent with the number of the ceramic filter cartridges and corresponds one to one. The upper end of the ceramic filter cartridge is open, and the upper end of the ceramic filter cartridge is sealed and connected to the corresponding upper flower plate holes. The pressing device is provided with openings, and the number of the openings is consistent with the number of the catalytic ceramic fiber filter tubes and corresponds one to one. The waste heat utilization device (6) is connected to the chimney (8) through the induced draft fan (7).

2. The steel rolling heating furnace ceramic fiber filter tube desulfurization, denitrification and dust removal coordinated treatment system according to claim 1 is characterized by: The air-classifying grinder (13) is connected to the desulfurizing agent bin (11), and a metering and mixing device (12) is provided between the air-classifying grinder (13) and the desulfurizing agent bin (11).

3. The steel rolling heating furnace ceramic fiber filter tube desulfurization, denitrification and dust removal coordinated treatment system according to claim 1 is characterized by: The first ammonia spraying section (3) is connected to an ammonia water station (9), and the protective agent spraying section (4) is connected to a protective agent bin (10).

4. The steel rolling heating furnace ceramic fiber filter tube desulfurization, denitrification and dust removal coordinated treatment system according to claim 1 is characterized by: The inlet of the dry desulfurization reactor (2) is connected to the heat exchanger (1).

5. The steel rolling heating furnace ceramic fiber filter tube desulfurization, denitrification and dust removal coordinated treatment system according to claim 1 is characterized by: The ammonia spraying section (3) comprises an ammonia water tank, an ammonia water vaporizer, an ammonia water dilution fan, an ammonia water metering and mixing module, and a spray device.

6. The steel rolling heating furnace ceramic fiber filter tube desulfurization, denitrification and dust removal coordinated treatment system according to claim 1 is characterized by: The ash hopper is connected to the ash conveying system, and the ash conveying system is provided with an ash conveying bin pump, a collecting ash bin, an ash conveying pipeline, and an ash conveying valve.

7. The steel rolling heating furnace ceramic fiber filter tube desulfurization, denitrification and dust removal coordinated treatment system according to claim 1 is characterized by: The clamping device and the flower plate are provided with anti-swaying devices, and a short tube is installed between the clamping device and the flower plate.

8. The steel rolling heating furnace ceramic fiber filter tube desulfurization, denitrification and dust removal coordinated treatment system according to claim 1 is characterized by: The cylinder wall of the catalytic ceramic fiber filter tube includes a dust removal layer and a denitration layer from the outside to the inside; the dust removal layer is a ceramic fiber layer, and the denitration layer is a ceramic fiber layer with a denitration catalyst attached.

9. The steel rolling heating furnace ceramic fiber filter tube desulfurization, denitrification and dust removal coordinated treatment system according to claim 1 is characterized by: The dry desulfurization reactor (2), the dust and saltpeter integrated device (5), and the waste heat utilization device (6) are connected to an electrical control system.

10. The steel rolling heating furnace ceramic fiber filter tube desulfurization, denitrification and dust removal coordinated treatment system according to claim 9 is characterized in that The electric control system is a DCS or PLC control system.

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