Anti-blocking device for high-temperature SCR (Selective Catalytic Reduction) denitration catalyst for boiler flue gas

Abstract

The utility model discloses an anti-blocking device for a high-temperature SCR (Selective Catalytic Reduction) denitration catalyst of boiler flue gas, which belongs to the technical field of boiler flue gas treatment and comprises an anti-ash-blocking component correspondingly arranged at the top of a boiler flue, and the anti-ash-blocking component is positioned above the SCR catalyst and is provided with a plurality of layers of SCR catalysts arranged along the boiler flue from bottom to top. And the anti-ash-blocking assembly is of a herringbone structure. Flue gas is purified and removed before passing through an SCR catalyst, efficient and stable operation of the SCR catalyst and up-to-standard emission of boiler flue gas are guaranteed, power consumption of a boiler system is reduced, and the operation period of a boiler is prolonged; the anti-clogging assembly does not need to be provided with a catalyst dust removal pretreatment device, and investment cost increase caused by high-temperature dust removal is avoided; a herringbone ash blocking prevention assembly and a mechanical ash blowing device are arranged above an SCR catalyst, large-particle fly ash in boiler flue gas can be removed, blocking of the catalyst and a tail air pre-heater is reduced, and power consumption of an induced draft fan is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of boiler flue gas treatment, in particular to an anti-blocking device for a boiler flue gas high-temperature SCR denitration catalyst. Background Art

[0002] As environmental protection requirements in various places become increasingly stringent, biomass boiler flue gas emission standards are becoming more and more stringent. Many places have issued ultra-low emission standards for biomass. The specific emission requirements are as follows: Particles ≤ 10mg / Nm 3 、Sulfur dioxide ≤35mg / Nm 3 、Nitrogen oxides ≤50mg / Nm 3 At present, the circulating fluidized bed boilers of biomass power plants generally adopt low-temperature combustion design to control the original amount of boiler nitrogen oxides produced. The furnace design temperature of biomass circulating fluidized bed boilers is basically 750~800℃, which cannot meet the reaction temperature requirement of 850~1050℃ of SNCR denitrification technology. This makes the original SNCR denitrification devices in the furnace of many power plants unusable, and the boiler nitrogen oxide emissions basically meet the 100mg / m in GB13223-2011. 3 It is difficult to reach the emission requirement of 50mg / m 3 Therefore, most biomass power plants use compressed oxygen combustion to control boiler NO x The original production volume leads to incomplete combustion of biomass boilers, and the carbon monoxide concentration in the flue gas is very high, which has a great impact on the efficiency of biomass boilers. Even so, the NO x It is difficult to meet ultra-low emission requirements.

[0003] In order to meet the ultra-low emission requirements of flue gas from circulating fluidized bed boilers in biomass power plants, the most mature and reliable denitrification technology is SCR denitrification technology, which is divided into two technical routes: medium-high temperature SCR denitrification and low-temperature SCR denitrification. The reaction temperature of the low-temperature SCR catalyst is about 200°C. It is generally arranged after the bag filter, which can effectively avoid the problem of alkali metal poisoning of the low-temperature SCR catalyst. However, the low-temperature SCR catalyst has poor resistance to sulfur poisoning and tar poisoning, especially after the combustion of biomass fuel, the flue gas contains a large amount of tar, which will condense on the surface of the low-temperature SCR catalyst, which can easily cause the low-temperature SCR catalyst to be poisoned. In addition, the low-temperature SCR catalyst is relatively expensive, and the investment cost is relatively high. The medium and high temperature SCR catalyst is rarely used in circulating fluidized bed boilers of biomass power plants. However, due to the high reaction temperature, generally at 280~420℃, it can effectively solve the problems of catalyst sulfur poisoning and tar poisoning in low-temperature SCR. It is also relatively cheap and is more widely used in circulating fluidized bed boilers of biomass power plants. However, the content of alkali metals (K, Na, etc.) in biomass fuel is very high. The soluble alkali metal salts in the flue gas after the combustion of biomass fuel can easily cause the medium and high temperature SCR catalyst to be blocked and poisoned, affecting the long-term stable operation and emission compliance of the circulating fluidized bed boiler of the biomass power plant. Therefore, it is particularly important to solve the blockage problem of the medium and high temperature SCR catalyst in the circulating fluidized bed boiler of the biomass power plant. Utility Model Content

[0004] Technical problem to be solved: In view of the possible blockage and poisoning problems of medium and high temperature SCR catalysts during use, the utility model provides an anti-blockage device for high-temperature SCR denitrification catalysts in boiler flue gas. The flue gas generated by the boiler is purified and removed before passing through the SCR catalyst, ensuring efficient and stable operation of the SCR catalyst and compliance with boiler flue gas emission standards, reducing boiler system power consumption and extending the boiler operation cycle.

[0005] Technical solution: The utility model describes an anti-blocking device for a high-temperature SCR denitrification catalyst for boiler flue gas, a multi-layer SCR catalyst arranged from bottom to top along the boiler flue, and the anti-blocking device includes an anti-blocking ash component correspondingly arranged at the top of the boiler flue, the anti-blocking ash component is located above the SCR catalyst, and the anti-blocking ash component is a "herringbone" structure.

[0006] Preferably, the anti-ash blocking assembly includes a supporting top beam arranged in the center along the length direction of the boiler flue, and a plurality of fixed top plates are arranged at equal intervals and tilted along the length direction on both sides of the supporting top beam, and the top end of the fixed top plate is provided with a connecting end fixedly connected to the side of the supporting top beam, and the bottom end of the fixed top plate is fixedly connected to the inner wall of the boiler flue; a fixed angle steel is correspondingly arranged on the lower side of the fixed top plate, and the fixed angle steel is connected to the fixed top plate by connecting bolts; a filter mesh plate is arranged on the slope formed by the fixed top plates on both sides of the supporting top beam, and the filter mesh plate is fixedly clamped between the fixed top plate and the fixed angle steel.

[0007] Preferably, a plurality of longitudinal support beams are relatively arranged on the wall surfaces on both sides of the boiler flue, and the top ends of the plurality of longitudinal support beams are horizontally connected with support angle seats for fixing the top plate and the fixed angle steels.

[0008] Preferably, a plurality of supporting longitudinal rods are arranged below the walls on both sides of the boiler flue corresponding to the longitudinal support beams, the top ends of the plurality of supporting longitudinal rods are horizontally connected with supporting cross rods, and a supporting inclined plate is arranged on the side corresponding to the supporting cross rod and the longitudinal support beam, and the bottom end of the longitudinal support beam is fixedly supported on the supporting inclined plate.

[0009] Preferably, a mechanical soot blowing device is provided above the anti-soot blocking assembly in the boiler flue.

[0010] Preferably, the boiler flue is provided with multiple layers of horizontal beams along its height direction, and support channel steels for fixing and supporting the SCR catalyst are respectively provided on both sides of the horizontal beams.

[0011] Compared with the prior art, the utility model has the following beneficial effects:

[0012] 1. The anti-clogging device of the utility model purifies and removes the flue gas generated by the boiler before it passes through the SCR catalyst, effectively solving the problem of SCR catalyst clogging, ensuring the efficient and stable operation of the SCR catalyst and the standard emission of boiler flue gas, reducing the power consumption of the boiler system and extending the operation cycle of the boiler;

[0013] 2. The anti-blocking ash component does not need to be equipped with a catalyst dust removal pretreatment device, avoiding the increase in investment costs caused by high-temperature dust removal; a "herringbone" anti-blocking ash component and a mechanical soot blowing device are arranged above the SCR catalyst, which can remove large particles of fly ash in the boiler flue gas, reduce the blockage of the catalyst and the tail air preheater, and reduce the power consumption of the induced draft fan;

[0014] 3. The use of SCR catalyst anti-clogging device can effectively reduce the risk of SCR catalyst poisoning and failure caused by alkali metals in biomass fuel; it can intercept a large amount of unburned biomass fuel particles in the boiler flue gas, reduce the risk of secondary combustion, and avoid high-temperature sintering failure of SCR catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the layout structure of the boiler flue anti-blocking device of the utility model;

[0016] Figure 2 for Figure 1 A top view of the layout structure of the middle anti-blocking device;

[0017] Figure 3 for Figure 1 Bottom view of the layout structure of the middle anti-blocking device;

[0018] Figure 4 for Figure 1 A schematic diagram of the structure enlargement in the middle;

[0019] Figure 5 for Figure 1 A magnified schematic diagram of the structure at B in the middle;

[0020] Figure 6 for Figure 1 A magnified schematic diagram of the structure at C in the middle;

[0021] Figure 7 for Figure 1 A magnified schematic diagram of the structure at D in the middle;

[0022] Figure 8 for Figure 2 Enlarged schematic diagram of the structure at point E in the middle.

[0023] Figure numerals: 1. boiler flue; 2. mechanical soot blowing device; 3. anti-ash blocking assembly; 31. supporting top beam; 32. fixed top plate; 321. connecting end; 33. fixed angle steel; 34. filter screen plate; 35. connecting bolt; 36. supporting angle seat; 4. longitudinal supporting beam; 5. horizontal beam frame; 6. SCR catalyst; 7. supporting longitudinal rod; 8. supporting cross rod; 9. supporting inclined plate; 10. supporting channel steel. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the embodiments of the present utility model clearer, the following will be combined with the attached Figures 1 to 8 The technical scheme of the embodiment of the utility model is clearly and completely described. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the described embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the utility model.

[0025] like Figures 1 to 3 and Figure 6As shown, the utility model is an anti-blocking device for a high-temperature SCR denitrification catalyst of boiler flue gas, with multiple layers of SCR catalysts 6 arranged from bottom to top along the boiler flue 1, and the boiler flue 1 is provided with multiple layers of horizontal beams 5 along its height direction, and support channels 10 for fixing and supporting the SCR catalysts 6 are respectively arranged on both sides of the horizontal beams 5. The efficiency of the catalytic reaction of the purified flue gas can be improved by the multi-stage SCR catalyst 6. The anti-blocking device includes an anti-blocking ash component 3 correspondingly arranged at the top of the boiler flue 1, the anti-blocking ash component 3 is located above the SCR catalyst 6, and the anti-blocking ash component 3 is a "herringbone" structure. The anti-blocking device of the utility model purifies and removes the flue gas generated by the boiler before it passes through the SCR catalyst, effectively solving the problem of SCR catalyst blockage, ensuring the efficient and stable operation of the SCR catalyst and the standard emission of the boiler flue gas, reducing the power consumption of the boiler system, and extending the operation cycle of the boiler.

[0026] In a preferred embodiment, if Figures 4 and 5 and Figure 8 As shown, the anti-blocking ash assembly 3 includes a supporting top beam 31 arranged in the center along the length direction of the boiler flue 1, and multiple fixed top plates 32 are arranged at equal intervals and tilted along the length direction on both sides of the supporting top beam 31. The top of the fixed top plate 32 is provided with a connecting end 321 fixedly connected to the side of the supporting top beam 31, and the bottom of the fixed top plate 32 is fixedly connected to the inner wall of the boiler flue 1; a fixed angle steel 33 is correspondingly arranged on the lower side of the fixed top plate 32, and the fixed angle steel 33 is connected to the fixed top plate 32 through a connecting bolt 35; a filter screen plate 34 is arranged along the slope formed by the fixed top plates 32 on both sides of the supporting top beam 31, and the filter screen plate 34 is fixedly clamped between the fixed top plate 32 and the fixed angle steel 33. The anti-blocking ash assembly does not need to be provided with a catalyst dust removal pretreatment device, avoiding the increase in investment cost caused by high-temperature dust removal; a "herringbone" anti-blocking ash assembly and a mechanical soot blowing device are arranged above the SCR catalyst, which can remove large particles of fly ash in the boiler flue gas, reduce the blockage of the catalyst and the tail air preheater, and reduce the power consumption of the induced draft fan.

[0027] In a preferred embodiment, if Figures 5 to 7 As shown, multiple longitudinal support beams 4 are arranged on the walls on both sides of the boiler flue 1, and the top ends of the multiple longitudinal support beams 4 are horizontally connected with support angle seats 36 for fixed support of fixed top plates 32 and fixed angle steels 33. Multiple supporting longitudinal rods 7 are arranged below the walls on both sides of the boiler flue 1 corresponding to the longitudinal support beams 4, and the top ends of the multiple supporting longitudinal rods 7 are horizontally connected with supporting cross bars 8, and the supporting cross bars 8 are arranged on the side corresponding to the longitudinal support beams 4. The bottom ends of the longitudinal support beams 4 are fixedly supported on the supporting inclined plates 9; this structure can form a stable support for the anti-blocking ash assembly 3.

[0028] In a preferred embodiment, if Figure 1As shown, the boiler flue 1 is provided with a mechanical soot blowing device 2 above the anti-blocking ash assembly 3, and the mechanical soot blowing device 2 can periodically blow the filter screen plate 34 to improve the filtering efficiency of the anti-blocking ash assembly.

[0029] 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 device for a boiler flue gas high-temperature SCR denitration catalyst, comprising a plurality of layers of SCR catalysts (6) arranged from bottom to top along a boiler flue (1), characterized in that: The anti-blocking device comprises an anti-blocking ash component (3) correspondingly arranged at the top of the boiler flue (1), the anti-blocking ash component (3) being located above the SCR catalyst (6), and the anti-blocking ash component (3) being a "herringbone" structure.

2. The anti-clogging device for boiler flue gas high-temperature SCR denitration catalyst according to claim 1, characterized in that: The anti-blocking ash assembly (3) comprises a supporting top beam (31) arranged in the center along the length direction of the boiler flue (1); a plurality of fixed top plates (32) are arranged at equal intervals and tilted along the length direction on both sides of the supporting top beam (31); a connecting end (321) fixedly connected to the side of the supporting top beam (31) is arranged at the top of the fixed top plate (32); and the bottom end of the fixed top plate (32) is fixedly connected to the inner wall of the boiler flue (1); a fixed angle steel (33) is correspondingly arranged at the lower side of the fixed top plate (32); the fixed angle steel (33) is connected to the fixed top plate (32) by connecting bolts (35); and a filter screen plate (34) is arranged along the slope formed by the fixed top plates (32) on both sides of the supporting top beam (31); the filter screen plate (34) is fixedly clamped between the fixed top plate (32) and the fixed angle steel (33).

3. The anti-clogging device for boiler flue gas high-temperature SCR denitration catalyst according to claim 2, characterized in that: A plurality of longitudinal support beams (4) are arranged opposite to each other on the wall surfaces of both sides of the boiler flue (1), and the top ends of the plurality of longitudinal support beams (4) are horizontally connected with support angle seats (36) for fixedly supporting a fixed top plate (32) and a fixed angle steel (33).

4. The anti-clogging device for boiler flue gas high-temperature SCR denitration catalyst according to claim 3, characterized in that: A plurality of supporting longitudinal rods (7) are arranged below the wall surfaces on both sides of the boiler flue (1) and corresponding to the longitudinal support beams (4); the top ends of the plurality of supporting longitudinal rods (7) are horizontally connected to supporting cross rods (8); and a supporting inclined plate (9) is arranged on one side of the supporting cross rod (8) corresponding to the longitudinal support beam (4); and the bottom end of the longitudinal support beam (4) is fixedly supported on the supporting inclined plate (9).

5. The anti-clogging device for boiler flue gas high-temperature SCR denitration catalyst according to any one of claims 1 to 4, characterized in that: The boiler flue (1) is provided with a mechanical soot blowing device (2) located above the anti-soot blocking component (3).

6. The anti-clogging device for boiler flue gas high-temperature SCR denitration catalyst according to claim 5, characterized in that: The boiler flue (1) is provided with multiple layers of horizontal beam frames (5) along its height direction, and support channel steels (10) for fixing and supporting the SCR catalyst (6) are respectively provided on both sides of the horizontal beam frames (5).

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