Anti-blocking SCR (Selective Catalytic Reduction) catalytic system for grate furnace biomass boiler
By designing multi-stage purification treatment in the SCR catalytic system of the biomass boiler, including the combination of partition plates and filter screens, and the use of cyclone dust collectors, the problem of catalyst clogging is solved and the efficiency and life of the catalyst are improved.
Patent Information
- Application Number
- CN202420299420.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-19
- Publication Date
- 2025-01-21
- Estimated Expiration
- 2034-02-19
AI Technical Summary
In the application of water-cooled vibrating grate biomass boilers, SCR catalysts are easily blocked due to the charcoal strips bypass, resulting in the catalyst failure.
An anti-clogging SCR catalytic system is designed, which includes a catalytic device and a dust removal device. The catalytic device performs multi-stage purification through partition plates and filter screens, and the dust removal device further purifies the flue gas through a cyclone dust collector to extend the service life of the catalyst.
Through multi-stage purification treatment, the catalytic efficiency and service life of the SCR catalyst are effectively improved, and the problem of catalyst failure due to carbon strip blockage is avoided.
Smart Images
Figure CN222368773U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of flue gas purification, and in particular relates to an anti-clogging SCR catalytic system for a grate furnace biomass boiler. Background Art
[0002] In recent years, pollutant emission standards have become increasingly stringent. Domestic provinces have required that the NOx content in biomass boiler flue gas should be within 50mg / Nm 3 The stringent requirement requires that the flue gas from biomass boilers must be purified using the SCR denitrification process. The technology of medium and high temperature SCR catalysts is already very mature. The catalyst has the advantages of avoiding ammonium bisulfate poisoning, low price, and high denitrification efficiency. However, the application of this technology in water-cooled vibrating grate biomass boilers is not ideal. This is mainly because the water-cooled vibrating grate vibrates periodically, and a large amount of carbon strips after the burning of straw are brought out by the flue gas during the vibration process. The size of such carbon strips is generally 5~10cm, which is easy to bridge on the catalyst surface, causing the SCR catalyst to be blocked, and ultimately leading to SCR failure. Utility Model Content
[0003] The technical problem solved by the utility model is as follows: In view of the problem that SCR catalysts are easily blocked and fail in the application of water-cooled vibrating grate biomass boilers, the utility model provides an anti-blocking SCR catalytic system for grate biomass boilers. The flue gas from the grate biomass boiler is removed through multi-stage purification, thereby improving the catalytic efficiency and service life of the SCR catalyst.
[0004] Technical solution: The utility model discloses an anti-clogging SCR catalytic system for a biomass boiler in a grate furnace, wherein the SCR catalytic system comprises a catalytic device and a dust removal device;
[0005] The catalytic device comprises a catalytic shell, a partition plate and a filter screen are arranged on the upper part of the catalytic shell from top to bottom, a wind cavity is formed between the upper part of the partition plate and the catalytic shell, a purification cavity is formed between the partition plate and the filter screen, a catalytic cavity is formed between the lower part of the filter screen and the catalytic shell, and at least one SCR catalytic layer is arranged in layers from top to bottom in the catalytic cavity;
[0006] The inlet end of the dust removal device is communicated with a side wall of the air passage cavity through an air inlet duct, and the outlet end of the dust removal device is communicated with a side wall of the purification cavity through an air exhaust duct.
[0007] Preferably, an air inlet pipe is provided on one side of the top of the catalytic housing;
[0008] The partition plate is arranged to tilt upward from one side of the air inlet pipe, and the tilt angle between the partition plate and the horizontal plane is 15°~45°.
[0009] Preferably, the filter screen is a herringbone structure with a high center and low surroundings.
[0010] Preferably, the mesh size of the filter screen is 50% to 70% of the pore size of the SCR catalyst.
[0011] Preferably, a discharge port is provided at the lower end of the connection between the side wall of the catalyst housing and the partition plate and the filter screen.
[0012] Preferably, the number of the SCR catalyst layers is 2 to 5 layers arranged from top to bottom along the catalyst cavity;
[0013] A soot blowing pipe extending into the center of the catalytic cavity is arranged above each SCR catalytic layer, and a high-pressure nozzle is arranged at one end of the inner side of the soot blowing pipe.
[0014] Preferably, the dust removal device is a cyclone dust collector, comprising a dust removal shell, an inlet end is arranged on one side of the upper portion of the dust removal shell, and an outlet end is arranged at the center of the top end of the dust removal shell.
[0015] Compared with the prior art, the utility model has at least the following beneficial effects:
[0016] In the SCR catalytic system of the utility model, the flue gas from the biomass boiler of the grate furnace first enters the air passage cavity, and the large-sized carbon bars are gathered on the partition plate due to their own weight for preliminary purification. The flue gas after preliminary purification enters the dust removal device through the air inlet duct for secondary purification to remove the large-sized carbon bars, and the flue gas purified by the dust removal device enters the purification cavity through the exhaust duct, and the small-sized carbon particles in the flue gas are further removed when passing through the filter screen, so as to realize deep purification treatment of the flue gas entering the catalytic cavity, and through multi-stage purification and removal, the catalytic efficiency and service life of the SCR catalyst are improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a schematic diagram of the SCR catalytic system flow of the utility model.
[0018] Figure numerals: 100, SCR catalytic system; 1, catalytic device; 11, catalytic shell; 12, partition plate; 13, filter screen; 14, air passage cavity; 15, purification cavity; 16, air inlet pipe; 17, catalytic cavity; 18, SCR catalytic layer; 19, soot blowing pipe; 110, high-pressure nozzle; 2, dust removal device; 21, dust removal shell; 22, inlet end; 23, outlet end; 3, air inlet duct; 4, exhaust duct. DETAILED DESCRIPTION
[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, Figure 1 The technical solutions of the embodiments of the utility model are described clearly and completely.
[0020] like Figure 1 In the illustrated embodiment, the utility model is an anti-clogging SCR catalytic system for a grate furnace biomass boiler, the SCR catalytic system 100 includes a catalytic device 1 and a dust removal device 2, the catalytic device 1 includes a catalytic shell 11, a partition plate 12 and a filter screen 13 are arranged on the upper part of the catalytic shell 11 from top to bottom, a wind cavity 14 is formed between the upper part of the partition plate 12 and the catalytic shell 11, a purification cavity 15 is formed between the partition plate 12 and the filter screen 13, a catalytic cavity 17 is formed between the lower part of the filter screen 13 and the catalytic shell 11, and at least one SCR catalytic layer 18 is arranged in layers from top to bottom in the catalytic cavity 17; the inlet end of the dust removal device 2 is connected to a side wall of the wind cavity 14 through an air inlet duct 3, and the outlet end of the dust removal device 2 is connected to a side wall of the purification cavity 15 through an exhaust duct 4. During operation, the flue gas from the grate furnace biomass boiler first enters the air passage cavity 14, and the large-sized carbon bars are gathered on the partition plate 12 due to their own weight for preliminary purification. The flue gas after preliminary purification enters the dust removal device through the air inlet duct 3 for secondary purification to remove large-particle carbon bars. The flue gas purified by the dust removal device enters the purification cavity 15 through the exhaust duct 4, and the small-sized carbon particles in the flue gas are further removed when passing through the filter screen 13, so as to achieve deep purification of the flue gas entering the catalytic cavity 17, thereby improving the catalytic efficiency and service life of the SCR catalyst.
[0021] In a preferred embodiment, an air inlet pipe 16 is provided on one side of the top of the catalytic housing 11, and the partition plate 12 is tilted upward from one side of the air inlet pipe 16, and the tilt angle between the partition plate 12 and the horizontal plane is 15° to 45°. A discharge port is provided at the lower end of the connection between the side wall of the catalytic housing 11 and the partition plate 12. The flue gas from the grate furnace biomass boiler enters the air passage cavity 14 through the air inlet pipe 16, and the large-sized carbon bars in the flue gas are gathered on the partition plate 12 due to their own weight and slide down to the lower end along the partition plate, and the carbon aggregates on the partition plate can be regularly removed through the discharge port.
[0022] In a preferred embodiment, the dust removal device 2 is a cyclone dust collector, which includes a dust removal housing 21, an inlet end 22 is provided on one side of the upper part of the dust removal housing 21, and an outlet end 23 is provided at the center of the top of the dust removal housing 21. The flue gas passing through the air cavity 14 enters the cyclone dust collector through the air inlet duct 3 for high-level purification and removal of carbon particles, and then is discharged from the outlet end of the cyclone dust collector. The flue gas purified and removed by the cyclone dust collector enters the purification cavity 15 of the catalytic housing along the exhaust duct 4.
[0023] In a preferred embodiment, the filter screen 13 is a "human" shaped structure with a high center and low surroundings. The mesh size of the filter screen 13 is 50% to 70% of the aperture of the SCR catalyst. The carbon strips are slender. If the mesh of the filter screen is too large, the carbon strips can easily pass through the filter screen, while if the mesh is too small, the filter screen is more likely to be clogged. A filter screen 13 with a suitable mesh can achieve a better purification effect on the flue gas. An exhaust port is provided at the lower end of the connection between the side wall of the catalytic housing 11 and the filter screen 13. The flue gas entering the purification chamber 15 can further filter out small carbon particles through the filter screen 13 to achieve deep purification of the flue gas. Small carbon particles will gradually accumulate around the filter screen 13 and can be periodically cleaned through the exhaust port.
[0024] In a preferred embodiment, the number of SCR catalytic layers 18 is 2 to 5 layers arranged from top to bottom along the catalytic cavity 17. Too many SCR catalytic layers 18 may increase the flue gas resistance, and a suitable number of SCR catalytic layers 18 can improve the catalytic efficiency of the flue gas. A soot blowing pipe 19 extending into the center of the catalytic cavity 17 is arranged above each layer of the SCR catalytic layer 18, and a high-pressure nozzle 110 is arranged at one end of the inner side of the soot blowing pipe 19. By periodically blowing and purifying the SCR catalytic layer, the service life of the SCR catalytic layer is further improved.
[0025] The above are preferred implementations of the present utility model. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present utility model. These improvements and modifications should also be regarded as the protection scope of the present utility model.
Claims
1. An anti-clogging SCR catalytic system for a grate furnace biomass boiler, characterized in that: The SCR catalytic system (100) comprises a catalytic device (1) and a dust removal device (2); The catalytic device (1) comprises a catalytic housing (11), a partition plate (12) and a filter screen (13) are arranged on the upper part of the catalytic housing (11) from top to bottom, an air passage cavity (14) is formed between the upper part of the partition plate (12) and the catalytic housing (11), a purification cavity (15) is formed between the lower part of the filter screen (13) and the catalytic housing (11), and a catalytic cavity (17) is formed between the lower part of the filter screen (13) and the catalytic housing (11), and at least one SCR catalytic layer (18) is arranged in layers from top to bottom in the catalytic cavity (17); The inlet end of the dust removal device (2) is connected to a side wall of the air passage cavity (14) through an air inlet duct (3), and the outlet end of the dust removal device (2) is connected to a side wall of the purification cavity (15) through an air exhaust duct (4).
2. The anti-clogging SCR catalytic system for a grate furnace biomass boiler according to claim 1 is characterized in that: An air inlet pipe (16) is provided on one side of the top of the catalytic shell (11); The partition plate (12) is arranged to be inclined upward from one side of the air inlet pipe (16), and the inclined angle between the partition plate (12) and the horizontal plane is 15° to 45°.
3. The anti-clogging SCR catalytic system for a grate furnace biomass boiler according to claim 2, characterized in that: The filter screen (13) is a herringbone structure with a high center and low surrounding areas.
4. The anti-clogging SCR catalytic system for a grate furnace biomass boiler according to claim 3, characterized in that: The mesh size of the filter screen (13) is 50% to 70% of the pore size of the SCR catalyst.
5. The anti-clogging SCR catalytic system for a grate furnace biomass boiler according to claim 1, characterized in that: A discharge port is provided at the lower end of the connection between the side wall of the catalytic housing (11) and the partition plate (12) and the filter screen (13).
6. The anti-clogging SCR catalytic system for a grate furnace biomass boiler according to claim 1, characterized in that: The number of the SCR catalyst layers (18) is 2 to 5 layers arranged from top to bottom along the catalyst cavity (17); A soot blowing pipe (19) extending into the center of the catalytic cavity (17) is arranged above each SCR catalytic layer (18), and a high-pressure nozzle (110) is arranged at one end of the inner side of the soot blowing pipe (19).
7. The anti-clogging SCR catalytic system for a grate furnace biomass boiler according to claim 1, characterized in that: The dust removal device (2) is a cyclone dust collector, comprising a dust removal shell (21), an inlet end (22) being provided at one side of the upper portion of the dust removal shell (21), and an outlet end (23) being provided at the center of the top end of the dust removal shell (21).