Flue gas flow equalizing grating at inlet of PDH waste heat boiler

Abstract

The invention discloses a PDH waste heat boiler inlet flue gas flow equalizing grille which comprises a set of ammonia conveying assembly, multiple sets of flow dividing assemblies, multiple sets of smoke sucking assemblies and a set of turbulence assemblies, the ammonia conveying assembly comprises a main ammonia conveying pipe and multiple branch pipes, and the ammonia conveying assembly is used for conveying mixed gas formed by ammonia gas and compressed air; an electromagnetic control valve is installed in each branch pipe and used for controlling on-off of fluid in the branch pipes. Ammonia gas output by the main ammonia conveying pipe sequentially flows into all the flow dividing assemblies, every time the ammonia gas flows into a certain flow dividing assembly, the smoke suction assembly near the flow dividing assembly can actively suck boiler smoke, the boiler smoke and the ammonia gas are fully mixed, in this way, only the ammonia gas flows into one flow dividing assembly each time, and therefore the boiler smoke can be fully mixed. And the flue gas is actively sucked and mixed, so that the problem of non-uniform mixing caused by directly laying a plurality of shunt pipes to cover the flue gas can be avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of flue gas denitrification, and particularly to a flue gas flow equalizing grid at the inlet of a PDH waste heat boiler. Background Art

[0002] The flue gas discharged from boilers is rich in nitrogen oxides such as high-concentration NO and NO2. To effectively address this environmental challenge, the SCR (Selective Catalytic Reduction) technology, with its excellent denitrification performance, stable operation performance, and smooth operation characteristics, has been widely adopted and recognized in the field of boiler flue gas treatment. As one of the core components of the SCR technology, the ammonia injection grid plays a crucial role in this process.

[0003] In order to make the ammonia injection grid mix more fully with the boiler flue gas, Chinese Patent Publication No. "CN210434278U" proposed a turbulent flow type ammonia injection grid for boiler flue gas denitrification. It mainly improves the mixing effect by setting multiple shunt pipes and nozzles and setting a turbulence ring. However, in this denitrification scheme, although numerous shunt pipes are designed to comprehensively cover the large-area flue gas generated by the boiler, there is a challenge: the uneven distribution of ammonia. Specifically, the shunt pipes close to the main ammonia injection pipe can smoothly receive a relatively sufficient ammonia supply. In contrast, the ammonia flow rate in the shunt pipes far from the main ammonia injection pipe significantly decreases. This uneven distribution directly leads to the non-uniformity of flue gas treatment, causing the flue gas areas far from the main pipe to fail to receive sufficient ammonia treatment, thereby affecting the overall flue gas purification effect, especially the flue gas treatment effect in those remote areas is greatly reduced. In view of this, the present application proposes a flue gas flow equalizing grid at the inlet of a PDH waste heat boiler. Summary of the Invention

[0004] The purpose of the present invention is to solve the disadvantages existing in the prior art, and to propose a flue gas flow equalizing grid at the inlet of a PDH waste heat boiler.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions: A flue gas flow equalizing grid at the inlet of a PDH waste heat boiler includes a group of ammonia delivery components, multiple shunt components, multiple smoking components, and a group of turbulence components. Among them, the ammonia delivery component includes a main ammonia delivery pipe and multiple branch pipes, and the ammonia delivery component is used for delivering a mixed gas formed by ammonia and compressed air; Each of the shunt components includes an arc-shaped pipe and two guide pipes, and the shunt component is used for shunting and delivering ammonia; The smoking component includes a negative pressure box, a power box, a power fan, and a centrifugal fan. Among them, the power fan is installed in the power box, and the centrifugal fan is installed in the negative pressure box to generate negative pressure and actively absorb boiler flue gas; The turbulent flow component includes a turbulent flow plate, a support rod, and a rolling ball. The turbulent flow component is used to generate turbulence when ammonia gas and flue gas are mixed, so that the ammonia gas and the flue gas are mixed more fully.

[0006] Preferably, the power fan is connected to the centrifugal fan through a connecting mechanism. The connecting mechanism is used for the power fan to drive the centrifugal fan to rotate. The air guide pipe communicates with the power box through an air blowing pipe.

[0007] Preferably, the connecting mechanism includes a connecting shaft and a plurality of connecting rods. The power fan is composed of an annular bracket and a plurality of fan blades. One end of the connecting rod is fixedly connected to the inner wall of the annular bracket, and the other end of the connecting rod is fixedly connected to the side wall of the connecting shaft. The connecting shaft is fixedly connected to the centrifugal fan.

[0008] Preferably, the smoke suction component further includes an ammonia discharge pipe, an exhaust pipe, a mixing pipe, a driving rod, a connecting rod, and a cleaning scraper. The ammonia discharge pipe communicates the power box with the mixing pipe. The exhaust pipe communicates the negative pressure box with the mixing pipe. A plurality of filter holes are formed in the side wall of the negative pressure box. The cleaning scraper is slidably arranged on the side wall of the negative pressure box. One end of the connecting rod is fixedly connected to the cleaning scraper, and the other end of the connecting rod is fixedly connected to the side wall of the driving rod. And the driving rod is pushed to move by a driving mechanism.

[0009] Preferably, the driving mechanism includes a driving box, an incomplete gear, a rack, and a return spring. The driving box is fixedly installed on the side wall of the negative pressure box. The incomplete gear is rotatably arranged in the driving box. And the rack is matched with the incomplete gear. The rack is slidably arranged in the driving box. One end of the return spring is fixedly connected to the lower side of the rack, and the other end of the return spring is fixedly connected to the inner bottom of the driving box. The connecting shaft is fixedly connected to the incomplete gear.

[0010] Preferably, a plurality of turbulence rings are slidably arranged in the mixing pipe. And a plurality of turbulence plates are fixedly connected to the inner wall of the turbulence ring. The plurality of turbulence rings are fixedly connected together through a vertical rod. One end of the driving rod away from the rack is fixedly connected to an adjacent turbulence ring.

[0011] Preferably, a plurality of turbulence grooves are formed in the lower end surface of the turbulence plate. And the plurality of turbulence grooves are equidistantly distributed along the circumferential direction of the turbulence plate.

[0012] Preferably, a hemispherical cover is fixedly connected to the lower end of the main ammonia delivery pipe. The rolling ball is rotatably arranged in the hemispherical cover. The upper end of the support rod is fixedly connected to the rolling ball, and the lower end of the support rod is fixedly connected to the upper end of the turbulence plate.

[0013] Preferably, a vibration spring is fixedly connected to the upper end of each mixing pipe. The upper end of the vibration spring is fixedly connected to the lower end of the turbulence plate.

[0014] Preferably, an electromagnetic control valve is installed in each of the branch pipes. The electromagnetic control valve is used to control the on-off of the fluid in the branch pipe, and the two air guide pipes are connected to both ends of the arc-shaped pipe; the smoking assembly is arranged between the two air guide pipes of adjacent shunt assemblies, and the arc-shaped pipe is communicated with the adjacent branch pipe.

[0015] The present invention has the following beneficial effects: 1. By setting the shunt assembly and the smoking assembly, the electromagnetic control valves in each branch pipe can be controlled to open and close in sequence, so that the ammonia gas output from the main ammonia delivery pipe can flow into each shunt assembly in sequence. And whenever the ammonia gas flows into a certain shunt assembly, the smoking assembly near the shunt assembly can actively suck the boiler flue gas in, and make the boiler flue gas fully mixed with the ammonia gas. In this way, only the ammonia gas flows into a group of shunt assemblies each time, and the flue gas is actively sucked in for mixing, which can avoid the problem of uneven mixing caused by directly laying multiple shunt pipes to cover the flue gas; 2. By setting the power fan, the connecting mechanism and the centrifugal fan, the power when the ammonia gas and the compressed air are discharged can be used to drive the power fan to rotate, and then drive the centrifugal fan to rotate through the connecting mechanism to generate negative pressure to actively absorb the boiler flue gas. On the one hand, there is no need to erect additional power-driven equipment, saving energy consumption. On the other hand, it can be realized that wherever the ammonia gas is transported, the flue gas is also absorbed to the same position, so that the flue gas can be thoroughly and fully treated; 3. By opening filter holes on the surface of the negative pressure box, solid particles in the flue gas can be effectively filtered, improving the purification effect of the flue gas. At the same time, by setting the driving mechanism, the driving rod and the cleaning scraper, the driving mechanism can be used to drive the driving rod and the cleaning scraper to continuously clean the surface of the negative pressure box, and the solid particles adsorbed on the surface of the negative pressure box can be quickly cleaned to avoid the blockage of the filter holes caused by the aggregation of solid particles; 4. By setting components such as the mixing pipe, the flow disturbing ring, and the flow disturbing plate, when the flue gas and the ammonia gas flow into the mixing pipe for mixing, the driving mechanism can also drive the flow disturbing plate to move up and down. In this way, the mixed gas in the mixing pipe can be continuously stirred, so that the ammonia gas and the flue gas are further mixed evenly, so that the mixed gas can react more fully; 5. By setting the mixing pipe, the vibration spring and the turbulence plate, since the electromagnetic control valves in each shunt assembly are opened and closed in sequence, the ammonia gas flows into each shunt assembly in sequence. Therefore, the mixed gas in each mixing pipe is also discharged in sequence. In this way, the mixed gas discharged from each mixing pipe can impact the turbulence plate in sequence, causing the turbulence plate to swing in all directions, which can make the mixed gas passing below generate turbulence, not only increasing the residence time of the mixed gas and making the reaction more complete, but also effectively stirring the mixed gas to make the ammonia gas and the flue gas mix evenly. Brief Description of the Drawings

[0016] Figure 1Schematic diagram of the overall external structure of a flue gas flow equalizing grid at the inlet of a PDH waste heat boiler proposed by the present invention; Figure 2 Schematic diagram of the connection structure of a group of shunt components, smoke suction components, turbulence components and other components in the present invention; Figure 3 For Figure 2 Enlarged schematic diagram of the structure at position A in Figure 4 For Figure 2 Enlarged schematic diagram of the structure at position B in Figure 5 Schematic diagram of the connection structure of components such as inside the negative pressure box, power fan, centrifugal fan, connection mechanism, driving rod, connecting rod, cleaning scraper and turbulence ring in the present invention; Figure 6 Schematic diagram of the connection structure of the inside of the negative pressure box, power fan and part of the driving mechanism in the present invention; Figure 7 Schematic diagram of the connection structure of components such as mixing pipe, turbulence ring, turbulence plate, driving rod, connecting rod, cleaning scraper, rack and return spring in the present invention; Figure 8 Schematic diagram of the bottom structure of the turbulence plate in the present invention; Figure 9 Schematic diagram of the connection structure of the main ammonia pipeline, turbulence component, vibration spring and mixing pipe in the present invention.

[0017] In the figure: 1 main ammonia pipeline, 2 branch pipeline, 3 arc pipeline, 4 air guide pipe, 5 hemispherical cover, 6 rolling ball, 7 support rod, 8 smoke suction component, 801 power box, 802 negative pressure box, 803 driving box, 804 mixing pipe, 805 exhaust pipe, 806 ammonia discharge pipe, 807 driving rod, 808 air supply pipe, 809 connecting rod, 810 cleaning scraper, 811 filter hole, 9 turbulence plate, 10 vibration spring, 11 turbulence groove, 12 power fan, 13 connecting shaft, 14 connecting rod, 15 centrifugal fan, 16 turbulence plate, 17 turbulence ring, 18 vertical rod, 19 incomplete gear, 20 rack, 21 return spring. Specific embodiments

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with 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. Embodiment 1:

[0019] Refer to Figure 1, a flue gas flow equalizing grid at the inlet of a PDH waste heat boiler, comprising a group of ammonia injection components, multi-component flow splitting components, multiple groups of flue gas suction components 8 and a group of turbulence components. The ammonia injection components include a main ammonia injection pipe 1 and multiple branch pipes 2. The ammonia injection components are used to transport the mixed gas formed by ammonia gas and compressed air. An electromagnetic control valve is installed in each branch pipe 2, and the electromagnetic control valve is used to control the on-off of the fluid in the branch pipe 2; Each flow splitting component includes an arc-shaped pipe 3 and two air guide pipes 4. The flow splitting components are used to split and transport ammonia gas, and the two air guide pipes 4 are connected to both ends of the arc-shaped pipe 3; The flue gas suction component 8 is arranged between the two air guide pipes 4 of adjacent flow splitting components, and the arc-shaped pipe 3 is connected to the adjacent branch pipe 2.

[0020] The flue gas suction component 8 includes a negative pressure box 802, a power box 801, a power fan 12 and a centrifugal fan 15. The power fan 12 is installed in the power box 801, and the centrifugal fan 15 is installed in the negative pressure box 802 to generate negative pressure and actively suck the boiler flue gas. The power fan 12 is connected to the centrifugal fan 15 through a connecting mechanism, and the connecting mechanism is used for the power fan 12 to drive the centrifugal fan 15 to rotate. The air guide pipe 4 communicates with the power box 801 through an air blowing pipe 808; In this embodiment, the mixed gas of ammonia gas and compressed air is directly input into the main ammonia injection pipe 1 of the ammonia injection component. At this time, the electromagnetic control valves in each branch pipe 2 are opened and closed in sequence. Specifically, when the electromagnetic control valve in a certain branch pipe 2 is opened, the electromagnetic control valves in the remaining branch pipes 2 are all closed, that is, each branch pipe 2 transports the mixed gas of ammonia gas and compressed air in sequence; When the mixed gas of ammonia gas and compressed air is input into a certain branch pipe 2, it can be transported from this branch pipe 2 to the corresponding arc-shaped pipe 3, and output to the power box 801 through the two air guide pipes 4 and the two air blowing pipes 808. Finally, the mixed gas can drive the power fan 12 to rotate, and drive the centrifugal fan 15 to rotate through the connecting mechanism. After the centrifugal fan 15 rotates, it can generate negative pressure and actively suck the passing boiler flue gas into the negative pressure box 802. In this way, each time only ammonia gas flows into a group of flow splitting components, and the flue gas is actively sucked in for mixing, which can avoid the problem of uneven mixing caused by directly laying multiple flow splitting pipes to cover the flue gas. Embodiment Two:

[0021] Compared with Embodiment One, this embodiment further has: The connecting mechanism includes a connecting shaft 13 and multiple connecting rods 14. The power fan 12 is composed of an annular bracket and multiple fan blades. One end of the connecting rod 14 is fixedly connected to the inner wall of the annular bracket, and the other end of the connecting rod 14 is fixedly connected to the side wall of the connecting shaft 13. The connecting shaft 13 is fixedly connected to the centrifugal fan 15.

[0022] The smoking component 8 further includes an ammonia discharge pipe 806, an exhaust pipe 805, a mixing pipe 804, a driving rod 807, a connecting rod 809 and a cleaning scraper 810. The ammonia discharge pipe 806 communicates the power box 801 with the mixing pipe 804, the exhaust pipe 805 communicates the negative pressure box 802 with the mixing pipe 804. A plurality of filter holes 811 are formed in the side wall of the negative pressure box 802. The cleaning scraper 810 is slidably arranged on the side wall of the negative pressure box 802. One end of the connecting rod 809 is fixedly connected to the cleaning scraper 810, and the other end of the connecting rod 809 is fixedly connected to the side wall of the driving rod 807, and the driving rod 807 is pushed to move by a driving mechanism.

[0023] The driving mechanism includes a driving box 803, an incomplete gear 19, a rack 20 and a return spring 21. The driving box 803 is fixedly installed on the side wall of the negative pressure box 802. The incomplete gear 19 is rotatably arranged in the driving box 803, and the rack 20 is engaged with the incomplete gear 19. The rack 20 is slidably arranged in the driving box 803. One end of the return spring 21 is fixedly connected to the lower side of the rack 20, and the other end of the return spring 21 is fixedly connected to the inner bottom of the driving box 803. The connecting shaft 13 is fixedly connected to the incomplete gear 19. It should be noted that referring to Figure 6 , the incomplete gear 19 is specifically a gear with only partial teeth. When it rotates, it can intermittently drive the rack 20 to move.

[0024] Referring to Figure 2 , Figure 5 and Figure 6 , when the mixed gas of ammonia and compressed air is input from the air injection pipes 808 on both sides of the power box 801, it will act on the blades of the power fan 12 and then drive the power fan 12 to rotate. The power fan 12 can drive the centrifugal fan 15 to rotate through the connecting shaft 13 and the connecting rod 14; at the same time, the boiler flue gas will be filtered by the filter holes 811 on the surface of the negative pressure box 802 to remove solid particles, and the boiler flue gas can be effectively purified.

[0025] In addition, referring to Figure 6 , when the connecting shaft 13 rotates, it will also drive the incomplete gear 19 to rotate. When the incomplete gear 19 rotates, its toothed part will periodically pass by the rack 20. When the toothed part of the incomplete gear 19 passes by the rack 20, it can engage with the rack 20 and drive the rack 20 to move a certain distance. Then the incomplete gear 19 disengages from the rack 20, and the return spring 21 immediately pulls the rack 20 back to its original position. Thus, during the continuous rotation of the incomplete gear 19, the rack 20 can move up and down reciprocally. The rack 20 can drive the cleaning scraper 810 to move up and down synchronously through the driving rod 807 and the connecting rod 809. Referring to Figure 4 , when the cleaning scraper 810 slidably arranged on the surface of the negative pressure box 802 moves up and down continuously, it can effectively scrape and clean the solid particles intercepted on the surface of the negative pressure box 802, and prevent the solid particles from accumulating and causing the filter holes 811 to be blocked; Further, after the mixed gas of ammonia and compressed air drives the power fan 12 to rotate, it can be discharged into the mixing pipe 804 through the ammonia discharge pipe 806. Refer to Figure 4 , and the boiler flue gas inhaled by the negative pressure box 802 also enters the mixing pipe 804 through the exhaust pipe 805, and finally the ammonia and the flue gas can be mixed and reacted to carry out denitrification treatment on the flue gas.

[0026] Embodiment Three: Compared with Embodiment One and Embodiment Two, in this embodiment, a plurality of spoiler rings 17 are slidably arranged in the mixing pipe 804, and a plurality of spoiler plates 16 are fixedly connected to the inner wall of the spoiler ring 17. The plurality of spoiler rings 17 are fixedly connected together by a vertical rod 18. One end of the driving rod 807 away from the rack 20 is fixedly connected to an adjacent spoiler ring 17.

[0027] In this embodiment, according to the content in the above Embodiment Two, the rack 20 in the driving mechanism can drive the driving rod 807 to move up and down reciprocally. Then, the spoiler ring 17 fixedly connected to the driving rod 807 also moves up and down reciprocally, and drives the other spoiler rings 17 to move together through the vertical rod 18. Refer to Figure 5 and 7 , when the spoiler ring 17 moves up and down reciprocally in the mixing pipe 804, the spoiler ring 17 and the spoiler plates 16 can stir the mixed gas of ammonia and flue gas passing through the mixing pipe 804, making the two mix more fully and evenly, and further making the denitrification treatment reaction of the flue gas more complete, thereby improving the effective degree of the treatment of the flue gas. Embodiment Four:

[0028] Compared with Embodiments One to Three, the turbulent flow component in this embodiment includes a turbulent flow plate 9, a support rod 7 and a rolling ball 6. The turbulent flow component is used to generate turbulent flow when ammonia and flue gas are mixed, so that ammonia and flue gas are mixed more fully. A plurality of turbulent flow grooves 11 are formed on the lower end surface of the turbulent flow plate 9, and the plurality of turbulent flow grooves 11 are equidistantly distributed along the circumferential direction of the turbulent flow plate 9. By arranging the turbulent flow grooves 11, when the unreacted completely mixed gas of ammonia and flue gas is discharged from the mixing pipe 804, it will blow to the turbulent flow grooves 11 of the turbulent flow plate 9, and turbulent flow will occur, increasing the residence time of the mixed gas in this device, so that the reaction is more complete.

[0029] A hemispherical cover 5 is fixedly connected to the lower end of the main ammonia delivery pipe 1. The rolling ball 6 is arranged to roll in the hemispherical cover 5. The upper end of the support rod 7 is fixedly connected to the rolling ball 6, and the lower end of the support rod 7 is fixedly connected to the upper end of the turbulent flow plate 9. The upper end of each mixing pipe 804 is fixedly connected with a vibration spring 10, and the upper end of the vibration spring 10 is fixedly connected to the lower end of the turbulent flow plate 9. Specifically, by arranging the rolling ball 6 rolling in the hemispherical cover 5 and connecting the rolling ball 6 with the turbulent flow plate 9 through the support rod 7, it can conveniently cooperate with the turbulent flow plate 9 to swing in all directions, and the rolling ball 6 can roll in the corresponding direction.

[0030] In addition, by providing the vibrating spring 10, on the one hand, the turbulence plate 9 can be connected to the upper ends of the respective mixing pipes 804, and on the other hand, when the turbulence plate 9 swings, it can also pull the turbulence plate 9 back to its original position.

[0031] It is not difficult to find from the content of the first to the third embodiments that: since the mixed gas of ammonia and compressed air is sequentially input into the respective flow dividing components through the electromagnetic control valves in the respective branch pipes 2, and wherever the ammonia is transported, the flue gas is also absorbed to the same position, so finally the mixed gas of ammonia and ammonia is also sequentially discharged outward from the respective mixing pipes 804. Referring to Figure 1 and Figure 9 , whenever the mixed gas of ammonia and flue gas is discharged from a certain mixing pipe 804, the mixed gas flow will impact the corresponding side of the turbulence plate 9, so that the turbulence plate 9 is turned by a certain angle. As the mixed gas is sequentially ejected upward from the mixing pipes 804, it can cause the turbulence plate 9 to swing in all directions, which can generate turbulence in the mixed gas passing below, not only increasing the residence time of the mixed gas and making the reaction more thorough and complete, but also the continuously swinging turbulence plate 9 can effectively agitate the mixed gas and make the mixing of ammonia and flue gas more uniform.

[0032] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A PDH waste heat boiler inlet flue gas flow grid, comprising a group of ammonia delivery components, multiple groups of flow components, multiple groups of smoke components (8) and a group of turbulent components, characterized in that: The ammonia delivery component comprises a main ammonia delivery pipe (1) and a plurality of branch pipes (2), and the ammonia delivery component is used to deliver a mixed gas formed by ammonia and compressed air; Each of the flow splitting components comprises an arc-shaped tube (3) and two air guide tubes (4), and the flow splitting component is used for splitting and transporting ammonia gas; The smoking assembly (8) comprises a negative pressure box (802), a power box (801), a power fan (12) and a centrifugal fan (15), wherein the power fan (12) is installed in the power box (801), and the centrifugal fan (15) is installed in the negative pressure box (802) to generate negative pressure and actively absorb boiler smoke; The turbulence component comprises a turbulence plate (9), a support rod (7) and a rolling ball (6), and the turbulence component is used to generate turbulence when ammonia and flue gas are mixed, so that the ammonia and flue gas are mixed more fully.

2. A PDH waste heat boiler inlet flue gas equalizing grid according to claim 1, characterized in that: The power fan (12) is connected to the centrifugal fan (15) via a connecting mechanism, the connecting mechanism being used for the power fan (12) to drive the centrifugal fan (15) to rotate, and the air guide pipe (4) is connected to the power box (801) via an air blower pipe (808).

3. A PDH waste heat boiler inlet flue gas equalizing grid according to claim 2, characterized in that: The connection mechanism comprises a connection shaft (13) and a plurality of connecting rods (14); the power fan (12) comprises an annular bracket and a plurality of fan blades; one end of the connecting rod (14) is fixedly connected to the inner wall of the annular bracket; the other end of the connecting rod (14) is fixedly connected to the side wall of the connection shaft (13); and the connection shaft (13) is fixedly connected to the centrifugal fan (15).

4. The PDH waste heat boiler inlet flue gas equalizing grid according to claim 1, characterized in that: The smoking assembly (8) also includes an ammonia exhaust pipe (806), an exhaust pipe (805), a mixing pipe (804), a driving rod (807), a connecting rod (809) and a cleaning scraper (810); the ammonia exhaust pipe (806) is connected to the power box (801) and the mixing pipe (804); the exhaust pipe (805) is connected to the negative pressure box (802) and the mixing pipe (804); a plurality of filter holes (811) are provided on the side wall of the negative pressure box (802); the cleaning scraper (810) is slidably arranged on the side wall of the negative pressure box (802); one end of the connecting rod (809) is fixedly connected to the cleaning scraper (810); the other end of the connecting rod (809) is fixedly connected to the side wall of the driving rod (807); and the driving rod (807) is driven to move by a driving mechanism.

5. A PDH waste heat boiler inlet flue gas equalizing grid according to claim 4, characterized in that: The driving mechanism comprises a driving box (803), an incomplete gear (19), a rack (20) and a return spring (21); the driving box (803) is fixedly mounted on the side wall of the negative pressure box (802); the incomplete gear (19) is rotatably arranged in the driving box (803), and the rack (20) cooperates with the incomplete gear (19); the rack (20) is slidably arranged in the driving box (803); one end of the return spring (21) is fixedly connected to the lower side of the rack (20), and the other end of the return spring (21) is fixedly connected to the bottom of the driving box (803); and the connecting shaft (13) is fixedly connected to the incomplete gear (19).

6. A PDH waste heat boiler inlet flue gas equalizing grid according to claim 5, characterized in that: A plurality of spoiler rings (17) are slidably disposed in the mixing tube (804), and a plurality of spoiler plates (16) are fixedly connected to the inner wall of the spoiler ring (17). The plurality of spoiler rings (17) are fixedly connected together via a vertical rod (18), and an end of the driving rod (807) away from the rack (20) is fixedly connected to an adjacent spoiler ring (17).

7. The PDH waste heat boiler inlet flue gas equalizing grid according to claim 1, characterized in that: A plurality of turbulence grooves (11) are provided on the lower end surface of the turbulence plate (9), and the plurality of turbulence grooves (11) are distributed at equal intervals along the circumference of the turbulence plate (9).

8. The PDH waste heat boiler inlet flue gas equalizing grid according to claim 1, characterized in that: The lower end of the main ammonia delivery pipe (1) is fixedly connected to a hemispherical cover (5), the rolling ball (6) is rotatably arranged in the hemispherical cover (5), the upper end of the support rod (7) is fixedly connected to the rolling ball (6), and the lower end of the support rod (7) is fixedly connected to the upper end of the turbulence plate (9).

9. The PDH waste heat boiler inlet flue gas equalizing grid according to claim 4, characterized in that: The upper end of each mixing tube (804) is fixedly connected to a vibration spring (10), and the upper end of the vibration spring (10) is fixedly connected to the lower end of the turbulence plate (9).

10. The PDH waste heat boiler inlet flue gas equalizing grid according to claim 1, characterized in that: An electromagnetic control valve is installed in each branch pipe (2), and the electromagnetic control valve is used to control the flow of fluid in the branch pipe (2), and the two air guide pipes (4) are connected at both ends of the arc pipe (3); the smoking component (8) is arranged between the two air guide pipes (4) of adjacent diversion components, and the arc pipe (3) is connected to the adjacent branch pipe (2).

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