A Flue Gas SCR Denitrification and Dust Removal System for a Whole Bundle of Straw Combustion and Gasification Equipment

Abstract

The present invention belongs to the technical field of SCR denitration and dust removal, and specifically relates to an SCR denitration and dust removal system for the flue gas of a whole bale straw combustion gasification device, which includes a purification box body. The purification box body is connected to a boiler through an intake flue and an outlet flue; a plurality of purification layers are arranged vertically inside the purification box body. The purification layer includes a fixed frame, and installation grooves are uniformly arranged on the fixed frame. A catalyst is embedded in the installation groove. The catalyst is in a square block structure, and honeycomb-shaped direct ventilation channels are uniformly arranged on the upper surface of the catalyst; in this application, an air outlet and a dust suction port are arranged at the top position of the installation groove. Through the action of air flow scouring and differential pressure suction, the inner wall of the direct ventilation channel, especially the top opening area, is fully cleaned, the cleaning efficiency is improved, the passability of the catalyst is ensured, and the subsequent flue gas purification operation is promoted to proceed smoothly.

Description

Technical Field

[0001] The present invention belongs to the technical field of SCR denitration and dust removal, and specifically relates to an SCR denitration and dust removal system for the flue gas of a whole-bale straw combustion and gasification device. Background Art

[0002] Domestic biomass power plants generally adopt in-furnace SNCR denitration, and the denitration efficiency is relatively low. Especially for circulating fluidized bed boilers, the designed furnace temperature is basically around 750°C, which cannot reach the optimal temperature range of 850 - 1050°C for SNCR denitration, resulting in the inability to use SNCR denitration in many projects and failing to meet the ultra-low emission requirements.

[0003] Therefore, many biomass power plants adopt oxygen-depleted combustion to control the NOx emissions of boilers, resulting in incomplete combustion of biomass boilers, a particularly high CO concentration in the flue gas, which has a greater impact on the efficiency of biomass boilers. Even so, it is difficult for the NOx emissions of boilers to meet the ultra-low emission requirements.

[0004] At present, the most mature and reliable ultra-low emission denitration technology can only adopt SCR denitration technology, which is mainly divided into two technical routes: low-temperature SCR denitration and medium-high temperature SCR denitration.

[0005] The reaction temperature of low-temperature SCR catalysts is usually around 200°C, and they are arranged behind the bag filter, which can effectively avoid the problem of alkali metal poisoning of low-temperature SCR catalysts. However, the low-temperature SCR catalysts have very poor resistance to sulfur poisoning and tar poisoning. Especially, the flue gas after the combustion of biomass fuels contains a large amount of tar, and the tar will condense on the surface of the low-temperature SCR catalysts, easily causing the poisoning of the low-temperature SCR catalysts, and there are few application achievements in biomass power plants.

[0006] The reaction temperature of medium-high temperature SCR is generally 280 - 420°C. The cost of SCR catalysts is relatively low and they are not easily sulfur-poisoned, and there are many application achievements in the biomass industry;

[0007] When applied to the purification treatment of the flue gas generated by biomass boilers, through long-term investigation and research, it is found that the main factors affecting the stable and efficient operation of SCR denitration are that the particulate impurities contained in the flue gas accumulate in the pores of the catalyst, causing the blockage of the catalyst and affecting the gas permeability of the flue gas. Moreover, it is necessary to stop the purification operation and open the equipment for manual cleaning, which affects the purification efficiency of the flue gas. Summary of the Invention

[0008] In order to make up for the deficiencies of the prior art and solve the above technical problems; the present invention proposes an SCR denitration and dust removal system for the flue gas of a whole-bale straw combustion and gasification device, including a purification box body, and the purification box body is connected to the boiler through an intake flue and an outlet flue;

[0009] Inside the purification box body, a plurality of purification layers are arranged along the vertical direction. Each purification layer includes a fixed frame, and a plurality of installation grooves are evenly arranged on the fixed frame. A catalyst is embedded in each installation groove. The catalyst has a square structure, and a honeycomb-shaped direct ventilation channel is evenly arranged on the upper surface of the catalyst.

[0010] At the upper side of the catalyst in the inner wall of the installation groove, an air outlet is horizontally arranged. The air outlet communicates with the soot blowing module on the fixed frame. At the position of the inner wall of the installation groove opposite to the air outlet, a dust suction port is arranged. The dust suction port communicates with a bag dust collector device outside through a dust discharge pipe. A sonic soot blower is arranged below the purification layer, and the sonic soot blower is controlled by an external controller.

[0011] Preferably, the intake flue communicates with the second-stage economizer of the boiler and is connected to the third-stage economizer of the boiler. And a group of light pipe economizers are arranged at the position between the purification layer and the outlet flue at the bottom of the purification box body.

[0012] Preferably, side holes are evenly arranged on the side wall at the middle position in the vertical direction of the catalyst. The side holes horizontally extend through the catalyst to form a horizontal air channel.

[0013] Preferably, the soot blowing module includes a soot blowing cavity arranged on the side wall of the fixed frame. The soot blowing cavity communicates with a soot blowing fan, and the soot blowing cavity communicates with the air outlets on the side walls of each installation groove through a soot blowing pipe.

[0014] At the position of the side wall of the soot blowing cavity opposite to the horizontal air channel, an inflation hole is arranged, and the inflation hole communicates with the inside of the soot blowing cavity.

[0015] Preferably, a guide pipe is arranged at the position of the inner wall of the fixed frame corresponding to the horizontal air channel. The guide pipe horizontally penetrates through the horizontal air channels on the catalysts in the same row, and the end of the guide pipe extends into the inside of the soot blowing cavity and communicates with the soot blowing cavity. A plurality of guide air holes are evenly arranged on the side wall of the guide pipe; the cross-section of the guide pipe is smaller than the cross-section of the side hole.

[0016] Preferably, the cross-section of the guide pipe is rectangular, and one end of one side of the guide pipe is connected to the output end of a rotating device on the inner wall of the soot blowing cavity. The rotating device is controlled by an external controller.

[0017] Preferably, flow guiding blocks are arranged at both ends of the guide pipe. The cross-section of the flow guiding block is triangular.

[0018] Preferably, the guide air holes are distributed on the outer surface of the guide pipe at the position between the two flow guiding blocks on both sides.

[0019] Preferably, an isolation filter screen is arranged at a position on the top of the purification box body close to the intake flue, and the isolation filter screen adopts a herringbone design.

[0020] Preferably, a temperature sensor is arranged at the joint of the top of the purification box body and the intake flue, and an over-temperature emergency spraying system is arranged above the purification layer.

[0021] The beneficial effects of the present invention are as follows:

[0022] For the SCR denitration and dust removal system of the flue gas of a whole bale straw combustion gasification device described in the present invention, through the air outlet and the ash suction port arranged at the top position of the installation groove, the inner wall of the direct air duct, especially the top opening area, is fully cleaned through the airflow scouring and the differential pressure air suction effect, the cleaning efficiency is improved, the passability of the catalyst is ensured, and the subsequent flue gas purification operation is promoted to proceed smoothly. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below with reference to the drawings.

[0024] Figure 1 is a perspective view of the present invention;

[0025] Figure 2 is a schematic diagram of the internal structure of the purification box body of the present invention;

[0026] Figure 3 is a perspective view of the fixing frame in the present invention;

[0027] Figure 4 is a cross-sectional view of the fixing frame in the present invention;

[0028] Figure 5 is Figure 4 a partial enlarged view of part A in

[0029] Figure 6 is a cross-sectional view of the catalyst in the present invention;

[0030] Figure 7 is Figure 6 a partial enlarged view of part B in

[0031] In the figure: purification box body 1, intake flue 11, outlet flue 12, purification layer 2, fixing frame 21, installation groove 22, air outlet 221, ash suction port 222, ash discharge pipe 223, blowing cavity 23, blowing pipe 231, inflation hole 232, rotating device 233, air guide pipe 24, air guide hole 241, flow guiding block 242, catalyst 3, direct air duct 31, side hole 32. DETAILED DESCRIPTION OF THE INVENTION

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] Embodiment 1:

[0034] As shown in the accompanying drawings of the specification Figures 1-7 shown, a flue gas SCR denitrification and dust removal system for a whole bale of straw combustion gasification equipment includes a purification box body 1, and the purification box body 1 is connected to the whole bale of straw combustion gasification boiler equipment through an intake flue 11 and an outlet flue 12;

[0035] A plurality of purification layers 2 are arranged inside the purification box body 1 along the vertical direction. The purification layer 2 includes a fixed frame 21. Installation grooves 22 are uniformly arranged on the fixed frame 21. A catalyst 3 is embedded and installed inside the installation groove 22. The catalyst 3 has a square block structure, and honeycomb-shaped direct air channels 31 are uniformly arranged on the upper surface of the catalyst 3;

[0036] An air outlet 221 is transversely arranged at a position on the inner wall of the installation groove 22 above the catalyst 3. The air outlet 221 communicates with the soot blowing module on the fixed frame 21. A dust suction port 222 is arranged at a position on the inner wall of the installation groove 22 opposite to the air outlet 221. The dust suction port 222 communicates with an external bag dust removal device through a dust discharge pipe 223. An acoustic soot blower is arranged below the purification layer 2, and the acoustic soot blower is controlled by an external controller;

[0037] The intake flue 11 communicates with the second-stage economizer of the boiler, the intake flue 11 is connected to the third-stage economizer of the boiler, and a group of light tube economizers are arranged at a position between the purification layer 2 and the outlet flue 12 at the bottom of the purification box body 1.

[0038] Specific working process: During the operation of a boiler using a whole bale of straw as a biomass fuel, in order to reduce pollutants such as nitrogen oxides and particulate dust in the combustion flue gas, the flue gas SCR denitrification and dust removal system of the present application is arranged between the second-stage economizer and the third-stage economizer, so that the flue gas contacts the catalyst 3, and the nitrogen and oxygen pollutants in the flue gas are converted into nitrogen and water under the catalytic reduction effect, reducing the pollution of the atmosphere after flue gas emission; and the heat of the purified flue gas is fully collected through the third-stage economizer and the light tube economizer;

[0039] Specifically, in order to prevent a large amount of particulate dust contained in the flue gas from affecting the contact between nitrogen oxides and the catalyst 3, a large-particle isolation filter screen is provided at the top of the purification box body 1 near the intake flue 11, and a herringbone design is adopted, so that large-particle pollutants in the flue gas are intercepted above the isolation filter screen, reducing the particulate matter concentration in the flue gas in contact with the catalyst 3;

[0040] Further, as the flue gas flows downward inside the purification box body 1, it will successively pass through multiple purification layers 2. The square-shaped catalysts 3 are evenly arranged inside the purification layer 2. After the flue gas flows downward and contacts the catalyst 3, it flows downward along the direct ventilation channels 31 uniformly arranged on the catalyst 3. In this way, the flue gas is dispersed into uniform fine airflows, contacts the inner wall of the catalyst 3 in the direct ventilation channels 31 and undergoes a reduction reaction by the catalyst 3, so that nitrogen oxides in the flue gas are reduced to harmless substances such as nitrogen, thereby promoting the purification treatment of pollutants in the flue gas;

[0041] During the process of the flue gas flowing into the catalyst 3, since the flow is blocked and diverted when initially contacting the top of the catalyst 3, the concentration of soot particle impurities in the flue gas is relatively high at this time, and the flue gas flow rate decreases. Therefore, the particulate impurities in the flue gas are easily adhered to the top surface of the catalyst 3 and the top inlet of the direct ventilation channels 31. With the continuous accumulation of particulate impurities, blockage is particularly likely to occur in the direct ventilation channels 31 near the top opening; Therefore, for each installation slot 22 of the catalyst 3, an air outlet 221 and an ash suction port 222 are respectively provided at the upper side of the catalyst 3, and a corresponding acoustic soot blower is provided at the lower side of each catalyst 3, and the working end points to the bottom of the catalyst 3;

[0042] In this way, during the intermittent period of flue gas purification, the input of flue gas is stopped, and the soot blowing module is started. The pressurized air flow is introduced into the air outlet 221 and then flows out horizontally, and is sucked into the ash suction port 222, and is guided to relevant treatment equipment such as a bag dust removal device outside through the connected ash discharge pipe 223. During this process, an air pump device is connected to the ash discharge pipe 223 to provide power support for sucking in the horizontally purified air flow; Because a horizontal impact air flow is formed in the upper side area of the catalyst 3 inside the installation slot 22 and flushes the top surface of the catalyst 3, taking away the particulate impurities adhered to the top surface of the catalyst 3, and because the horizontal air flow increases the air flow rate in the upper side area of the catalyst 3, the air pressure in the upper side area of the catalyst 3 decreases, promoting the upward flow of air inside the direct ventilation channels 31 of the catalyst 3, so that the area near the top opening of the direct ventilation channels 31 is impacted by the reverse air flow, cleaning the particulate impurities adhered to the inner wall of the direct ventilation channels 31, and for some direct ventilation channels 31 that are blocked or even blocked due to the accumulation of particulate impurities in the top opening area, the reverse air flow impact effectively dredges them, restoring the smooth flow of the flue gas and enabling the normal functioning of the flue gas purification;

[0043] The sonic soot blower starting simultaneously at the lower side position of Catalyst 3 releases air flow accompanied by impact sound waves. The vibration impact loosens the impurities adhering to the inner wall of Catalyst 3, and they fall off under the impact of the upward air flow. The downward air flow replenishes the inside of the direct ventilation duct 31 and, under the attraction of the upper side area of Catalyst 3, continuously flushes the inner wall of the direct ventilation duct 31, especially the top opening area of the direct ventilation duct 31. Finally, it drives the particulate impurities falling off from Catalyst 3 to merge into the lateral air flow and enter the dust suction port 222, and then flow to the external impurity cleaning equipment for treatment. In this way, the air outlet 221 and the dust suction port 222 provided at the top position of the installation groove 22 in this application achieve full cleaning of the inner wall of the direct ventilation duct 31, especially the top opening area, through air flow flushing and differential pressure suction, improve the cleaning efficiency, ensure the passability of Catalyst 3, and promote the smooth progress of subsequent flue gas purification operations.

[0044] Furthermore, to avoid the problem of Catalyst 3 failing due to excessive temperature, a temperature sensor can be provided at the joint between the top of the purification box body 1 and the intake flue 11, and an existing over-temperature emergency spraying system is provided above the purification layer 2. When it is detected that the temperature is too high and may cause Catalyst 3 to fail and affect normal waste gas purification treatment, the over-temperature emergency spraying system is started to cool the flue gas and Catalyst 3, which can effectively extend the service life of Catalyst 3 and maintain the normal operation of the system in this application.

[0045] Embodiment 2:

[0046] On the basis of Embodiment 1, side holes 32 are uniformly provided on the side wall at the middle position in the vertical direction of Catalyst 3. The side holes 32 extend horizontally through Catalyst 3 to form a horizontal air duct. The side holes 32 are circular hole structures and the diameter is smaller than the width of the side wall of the corresponding direct ventilation duct 31.

[0047] Specific working process: On the basis of the specific working process in Embodiment 1, considering that when the inside of the direct ventilation duct 31 of Catalyst 3 is blocked or the flow is not smooth, it will cause the flue gas to be difficult to enter the blocked direct ventilation duct 31, resulting in the failure of the direct ventilation duct 31 and its inability to normally play the role of purifying the flue gas. Therefore, side holes 32 are provided on the side wall of Catalyst 3 to form a horizontal air duct. In this way, when the flue gas flows into the direct ventilation duct 31 and then flows downward to the side holes 32 corresponding to the horizontal air duct, part of the flue gas will flow horizontally into the adjacent direct ventilation duct 31. This slows down the vertical flow rate of the flue gas in the direct ventilation duct, increases the residence time, and makes the catalytic reduction reaction more sufficient.

[0048] Moreover, for the direct ventilation duct 31 with the blockage position on the upper side of the transverse air duct, the flue gas flowing laterally from the adjacent area will enter the blocked direct ventilation duct 31 and flow out from the bottom opening, avoiding the blockage position and being utilized in the area below the blockage position of the direct flue duct to participate in the reduction and purification treatment of the flue gas. Similarly, for the direct ventilation duct 31 with the blockage position on the lower side of the transverse air duct, after the flue gas flows in from the top and is blocked at the blockage position, it flows laterally into the adjacent direct ventilation duct 31 through the side holes 32 on the side wall, enabling the direct ventilation duct 31 located above the blockage position to participate in the purification treatment of the flue gas. In this way, even when the direct ventilation duct 31 is blocked, the contact area between the flue gas and the catalyst 3 can be effectively increased, and

[0049] the utilization efficiency of the catalyst 3 and the purification efficiency of the flue gas are improved, ensuring the passability of the flue gas through the catalyst 3.

[0050] Embodiment 3:

[0051] Based on Embodiment 2, there are various possible implementation schemes for the specific structure of the soot blowing module. Any technical solution that can satisfy the requirement of laterally releasing the pressurized flushing air flow from the air outlet 221 in each installation slot 22 can be applied to this application. In this embodiment, a possible technical solution is provided. Specifically, the soot blowing module includes a soot blowing chamber 23 provided on the side wall of the fixed frame 21. The soot blowing chamber 23 is communicated with a soot blowing fan, and the soot blowing chamber 23 is communicated with the air outlets 221 on the side walls of the respective installation slots 22 through a blowing air pipe 231. An inflation hole 232 is provided at a position on the side wall of the soot blowing chamber 23 facing the side hole 32, and the inflation hole 232 is internally communicated with the soot blowing chamber 23.

[0052] Specific working process: On the basis of the specific working process in Embodiment 2, during the intermittent period of the flue gas purification treatment, when it is necessary to clean the catalyst 3, the soot blowing fan is started. First, the outside air passes through the existing air filtration equipment at the air inlet end, is filtered and purified, and then pressurized and sent into the soot blowing chamber 23, increasing the internal air pressure of the soot blowing chamber 23. Subsequently, the purified air flow accelerates and flows into each air outlet 221 along the connected blowing air pipe 231, and then laterally flows out from the air outlet 221 and forms a lateral flushing air flow above the catalyst 3, thereby achieving a full cleaning of the top area of the catalyst 3 and ensuring the passability of the catalyst 3.

[0053] In the middle area inside the direct ventilation duct 31, since it is far from the upper and lower openings, when the cleaning air flow formed by the external soot blowing equipment reaches the middle area, the kinetic energy is severely consumed, and the cleaning effect on the particulate impurities on the side wall of the middle area inside the direct ventilation duct 31 is poor. Therefore, in order to enable the inner wall of the direct ventilation duct 31 to be more fully cleaned, an inflation hole 232 is provided to connect the transverse air duct in the catalyst 3 to the soot blowing chamber 23.

[0054] Open the control valve of the inflation hole 232, so that the air flow inside the soot blowing chamber 23 flows out from the inflation hole 232, passes through the side hole 32 and flows into the transverse air duct, and then enters each direct air duct 31 from the transverse flow channel respectively, so that the purified air flow participates in the scouring and cleaning of the direct air duct 31 from the inside to the outside and from the middle to the upper and lower sides;

[0055] Regarding the problem of poor circulation due to impurity accumulation in some bottom opening areas, when the air flow directly flowing into the interior from the transverse air duct flows outwards, on the one hand, it can flow upwards and be accelerated to scour the top opening area under the drive of the transverse air flow on the upper side of the catalyst 3; on the other hand, the air flow directly entering the middle area of the internal direct air duct 31 increases the air pressure in the middle area of the direct air duct 31, and because it is not weakened by the friction of the side wall of the direct air duct 31, it retains a large amount of kinetic energy. When flowing outwards and impacting, the particulate impurities accumulated on the inner wall of the middle area of the direct air duct 31, which are normally difficult to be effectively cleaned, are directly affected by the impact air flow and are discharged to the outside with the air flow, further ensuring the passability of the catalyst 3.

[0056] Embodiment Four:

[0057] On the basis of Embodiment Three, a gas guide pipe 24 is provided at the part of the inner wall of the fixed frame 21 corresponding to the transverse air duct. The gas guide pipe 24 transversely penetrates the transverse air ducts on the same row of catalysts 3, and the end of the gas guide pipe 24 extends into the soot blowing chamber 23 and is provided with a control valve. The gas guide pipe 24 communicates with the soot blowing chamber 23, and the side wall of the gas guide pipe 24 is evenly provided with gas guide holes 241; the cross section of the gas guide pipe 24 is smaller than the cross section of the transverse air duct.

[0058] The cross section of the gas guide pipe 24 is rectangular, and one end of the gas guide pipe 24 is connected to the output end of the rotating device 233 on the inner wall of the soot blowing chamber 23. The rotating device 233 is controlled by an external controller; specifically, an external gear can be provided on the outer circle of the pipe orifice of the gas guide pipe 24 located inside the soot blowing chamber 23. The rotating device 233 is selected as a motor device, and the driving gear provided at the output end meshes with the external gear to realize the indirect drive of the gas guide pipe 24 without affecting the air flow entering the gas guide pipe 24.

[0059] Specific working process: On the basis of the specific working process in Embodiment Three, in order to expand the action range of the scouring air flow entering the transverse air duct from the inflation hole 232, a gas guide pipe 24 is provided, so that the gas guide pipe 24 transversely passes through the corresponding transverse air ducts on each catalyst 3; in this way, the scouring air flow is filled into the gas guide pipe 24, and then the scouring air flow is restricted by the gas guide pipe 24, so that it concentrates along a stable flow trajectory and flows out from the gas guide holes 241 evenly provided on the side wall of the gas guide pipe 24, and is more evenly distributed to the direct air ducts 31 in the area far from the inflation hole 232, expanding the action range of the transverse scouring air flow;

[0060] And a rotating device 233 is arranged to be connected to the air duct 24, so that when starting to rotate, it can drive the air duct 24 to rotate slowly. The rotating air duct 24 can clean the particulate impurities that may adhere to the inner wall of the horizontal air duct, ensuring the smoothness of the horizontal air duct; the centrifugal force during rotation can clean the particulate impurities adhering to the surface of the air duct 24, preventing the accumulation of particulate impurities on the surface of the air duct 24 and thus avoiding blockage of the direct current air duct at the position of the air duct 24;

[0061] Furthermore, the cross-section of the air duct 24 is set as a flat rectangular structure, and when the flue gas flows, the two ends of the air duct 24 are controlled to be vertical, so that the horizontal projection is small and the obstruction to the downward flowing flue gas is small; when it is necessary to wash and clean the inner wall of the direct air duct 31, the rotating device 233 is controlled to rotate slowly; when the air duct 24 rotates to the horizontal state, at this time the horizontal projection area of the air duct 24 is large and the obstruction to the upward flowing air is large; through the setting of the controller, when the air duct 24 rotates to the vertical state, it stays for 3 - 5 s and then rotates to the horizontal state, and so on;

[0062] In this way, the air intercepted by the air duct 24 in the horizontal state is released in a short time when the air duct 24 rotates to the vertical state, forming a short-time intense impact air flow. The air flow accelerates through the position of the air duct 24 and flows upward, increasing the impact on the inner wall of the direct air duct 31, effectively dredging the blockage inside the direct air duct 31, so that the particulate impurities adhering to the inner wall of the direct air duct 31 are fully cleaned, ensuring the normal purification efficiency of the catalyst 3.

[0063] Embodiment Five:

[0064] On the basis of Embodiment Four, flow guiding blocks 242 are arranged at both ends of the air duct 24. The cross-section of the flow guiding block 242 is triangular, and the air guide holes 241 are distributed on the outer surface of the air duct 24 at the part between the two flow guiding blocks 242; that is, when the air duct 24 rotates to the vertical state, at this time the flow guiding blocks 242 are located on the upper and lower sides of the air duct 2, and the air guide holes 241 are located at the horizontal two-side positions of the outer surface of the air duct 2.

[0065] Specific working process: On the basis of the specific working process in Embodiment Four, during normal flue gas purification, the air duct 24 rotates to the vertical state, and the flow guiding blocks 242 located on the upper and lower sides guide the vertically flowing air to both sides, increasing the contact degree between the flue gas and the inner wall of the direct air duct 31, and at the same time reducing the direct impact on the air duct 24;

[0066] At this time, the air flowing downward from both side surfaces of the air duct 2 passes through the openings of the air guide holes 241 on both sides, causing a negative pressure to be formed at the openings of the air guide holes 241, so that the air inside the air duct 2 has a tendency to flow outwards, preventing particulate impurities in the flue gas from entering the inside of the air duct 2, and further reducing the occurrence of blockage inside the air duct 2.

[0067] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and all such changes and improvements fall within the scope of the present invention as claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A flue gas SCR denitrification and dust removal system for a whole bundle of straw combustion gasification equipment, comprising a purification box body (1), and the purification box body (1) is connected to a boiler through an intake flue (11) and an outlet flue (12); It is characterized in that: A plurality of purification layers (2) are arranged vertically inside the purification box body (1). The purification layer (2) includes a fixed frame (21). Installation grooves (22) are evenly arranged on the fixed frame (21). A catalyst (3) is embedded in the installation groove (22). The catalyst (3) is in a square block structure, and honeycomb-shaped direct air channels (31) are evenly arranged on the upper surface of the catalyst (3); An air outlet (221) is horizontally arranged at a position on the inner wall of the installation groove (22) above the catalyst (3). The air outlet (221) communicates with a soot blowing module on the fixed frame (21). A dust suction port (222) is arranged at a position on the inner wall of the installation groove (22) opposite to the air outlet (221). The dust suction port (222) communicates with an external bag dust collector through a dust discharge pipe (223). A sonic soot blower is arranged below the purification layer (2), and the sonic soot blower is controlled by an external controller; Side holes (32) are evenly arranged on the side wall at the middle position in the vertical direction of the catalyst (3). The side holes (32) extend horizontally through the catalyst (3) to form a horizontal air channel; The soot blowing module includes a soot blowing cavity (23) arranged on the side wall of the fixed frame (21). The soot blowing cavity (23) communicates with a soot blowing fan, and the soot blowing cavity (23) communicates with the air outlets (221) on the side walls of each installation groove (22) through a soot blowing pipe (231); An air inflation hole (232) is arranged at a position on the side wall of the soot blowing cavity (23) opposite to the horizontal air channel. The air inflation hole (232) communicates with the inside of the soot blowing cavity (23); A guide air pipe (24) is arranged at a position on the inner wall of the fixed frame (21) corresponding to the horizontal air channel. The guide air pipe (24) horizontally penetrates through the horizontal air channels on the catalysts (3) in the same row, and the end of the guide air pipe (24) extends into the soot blowing cavity (23) and communicates with the soot blowing cavity (23). Guide air holes (241) are evenly arranged on the side wall of the guide air pipe (24); The cross-section of the guide air pipe (24) is smaller than the cross-section of the side hole (32).

2. The flue gas SCR denitration and dust removal system of a whole bale straw combustion gasification device according to claim 1, characterized in that: The intake flue (11) communicates with the second-stage economizer of the boiler. The intake flue (11) is connected to the third-stage economizer of the boiler, and a group of light pipe economizers are arranged at a position between the purification layer (2) and the outlet flue (12) at the bottom of the purification box body (1).

3. A flue gas SCR denitration and dust removal system for a whole-bale straw combustion gasification device according to claim 1, characterized in that: The cross-section of the guide air pipe (24) is rectangular, and one end of one side of the guide air pipe (24) is connected to the output end of a rotating device (233) on the inner wall of the soot blowing cavity (23). The rotating device (233) is controlled by an external controller; 4. The flue gas SCR denitration and dust removal system of a whole bundle of straw combustion gasification device according to claim 3, characterized in that: Deflector blocks (242) are arranged at both ends of the guide air pipe (24). The cross-section of the deflector blocks (242) is triangular.

5. A flue gas SCR denitrification and dust removal system for a whole-bale straw combustion gasification device according to claim 4, characterized in that: The air guide holes (241) are distributed at the part of the outer surface of the air guide pipe (24) located between the two diversion blocks (242).

6. The flue gas SCR denitration and dust removal system of a whole bale straw combustion gasification device according to claim 1, characterized in that: An isolation filter screen is provided at the part of the top of the purification box body (1) close to the intake flue (11), and the isolation filter screen adopts a herringbone design.

7. A flue gas SCR denitration and dust removal system for a whole bale straw combustion gasification device according to claim 1, characterized in that: A temperature sensor is provided at the joint of the top of the purification box body (1) and the intake flue (11), and an over-temperature emergency spraying system is provided above the purification layer (2).

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