CN106345291B - Rotary-type low temperature SCR denitration and on-line continuous regenerating unit and its application - Google Patents

Abstract

The invention relates to a rotary wheel-type low-temperature SCR denitrification and online continuous regeneration device and its application. The device includes a rotary catalyst main unit, a regeneration airflow delivery fan and a regeneration airflow heater. The rotary catalyst main unit includes a catalyst runner that rotates intermittently, and The gas separation box at the inlet end and the gas separation box at the outlet end are respectively arranged at both ends of the catalyst runner. The gas separation box at the inlet end and the gas separation box at the outlet end jointly isolate the catalyst runner from the low-temperature SCR reaction zone and the catalyst in the circumferential direction. Regeneration pre-heating zone and thermal regeneration zone; the device is used for low-temperature denitrification treatment of industrial kiln flue gas including coking, steel sintering, alumina roasting, ceramics and glass firing. Compared with the prior art, the invention utilizes a uniquely designed runner device, which can simultaneously complete flue gas low-temperature SCR denitrification treatment and online continuous regeneration of the catalyst, with low energy consumption and long service life of the catalyst, which has a good application prospect.

Description

Rotary low-temperature SCR denitrification and online continuous regeneration device and its application

technical field

The invention belongs to the technical field of flue gas treatment, and relates to a wheel-type low-temperature SCR denitrification and online continuous regeneration device and its application.

Background technique

Nitrogen oxides are one of the main air pollutants, which can cause a series of problems such as acid rain and smog that damage the environment and affect human health. Therefore, the control of nitrogen oxides is the focus of current air pollution control. Among them, nitrogen oxides emitted from industrial kilns such as coking, steel sintering, alumina roasting, ceramics and glass firing have attracted more and more attention. The catalyst used in the conventional catalytic reduction denitrification (SCR) can only operate effectively for a long time above 300 °C. For the above-mentioned industries, since the flue gas temperature is generally lower than 250°C and contains certain catalyst poisoning substances, it is difficult for conventional catalysts to adapt to such low temperature conditions. Therefore, the development of low-temperature SCR catalysts is a current research hotspot.

However, for most low-temperature catalysts, the catalysts are poisoned or invalid due to the fact that they are prone to adsorb more harmful components or are covered by ammonium salts. Therefore, designing a suitable reaction and online regeneration device for low-temperature SCR technology is the key to popularize the application of this technology in the field of low-temperature denitrification of industrial furnace flue gas including coking, steel sintering, alumina roasting, ceramics and glass firing.

The Chinese invention patent with the authorized announcement number CN103816796B discloses a low-temperature coke oven flue gas desulfurization and denitrification process, by injecting fluidized NaHCO ₃ fine powder into the flue gas conveying pipeline, dry removal of coke oven flue gas At the same time, the denitrification catalyst structure layer and the ammonia removal catalyst structure layer are used together to efficiently remove _NOx in the coke oven flue gas. _The denitration catalyst adopts a filter cartridge structure, and the ammonia removal catalyst adopts a V-shaped Type structure; the process is composed of air induction unit, desulfurization unit, ammonia preparation unit, denitrification and ammonia removal unit, compressed air unit, and particle delivery unit to achieve efficient denitrification and desulfurization.

Contents of the invention

The purpose of the present invention is to provide a wheel-type low-temperature SCR denitrification and online continuous regeneration device and its application that can effectively increase the service life of the catalyst and significantly reduce energy consumption in order to overcome the above-mentioned defects in the prior art.

The purpose of the present invention can be achieved through the following technical solutions:

Rotary wheel type low-temperature SCR denitrification and online continuous regeneration device, the device includes a rotary catalytic main unit, and a regeneration airflow conveying fan and a regeneration airflow heater used in conjunction with the rotary catalytic main unit, and the rotary catalytic main unit includes The intermittently rotating catalyst runner, and the gas separation box at the inlet end and the gas separation box at the gas outlet respectively arranged at both ends of the catalyst runner, the gas separation box at the inlet end and the gas separation box at the gas outlet jointly make the catalyst runner A low-temperature SCR reaction zone, a catalyst regeneration preheating zone and a thermal regeneration zone are isolated in the circumferential direction.

The catalyst runner includes an outer casing with open ends and a hollow cavity, an inner cylinder inserted in the outer casing, and N radial partition plates uniformly arranged between the inner cylinder and the outer casing along the axial direction of the outer casing, wherein , N is an integer, and N≥2, the two ends of the inner cylinder are sealed, and the sealing surfaces of the partition boxes are respectively provided.

As a preferred technical solution, N is an integer, and 6≤N≤15.

The radial partition plate divides the cavity between the shell and the inner cylinder into N catalyst loading areas, where N is an integer and N≥2.

The catalyst loading area is filled with one or more of granular SCR catalysts, honeycomb SCR catalysts or corrugated plate SCR catalysts.

One side of the gas separation box at the inlet end is provided with a regeneration hot gas flow inlet, and the other side covers a catalyst loading area to form a first heat regeneration zone; one side of the gas separation box at the gas outlet end is provided with a regeneration heat flow inlet. The air outlet, the other side covers two adjacent catalyst loading areas at the same time, one of the covered catalyst loading areas forms a second thermal regeneration area connected to the first thermal regeneration area, and the first thermal regeneration area is connected to the second thermal regeneration area. The regeneration zone jointly forms a thermal regeneration zone, another covered catalyst loading zone forms a catalyst regeneration preheating zone, and the rest uncovered catalyst loading zones jointly form a low-temperature SCR reaction zone.

The diameter of the inner cylinder is 400-1200mm, the inner diameter of the outer shell is 1200-5000mm, and the effective length of the catalyst runner is 2000-4000mm.

Both ends of the catalyst runner are also respectively provided with an inlet end cover and an outlet end cover connected to the gas separation box at the inlet end and the gas outlet end. The end cover adopts mechanical seal.

The gas separation box at the inlet end, the gas separation box at the gas outlet end, and the catalyst runner are all compressed by springs. When rotation is required, an external force is used to pull the sealing surface of the separation box away from the section of the catalyst runner to prevent separation. The sealing surface of the box is worn out. After the rotation is in place, the external force is removed, so that the gas separation box at the inlet end, the gas separation box at the gas outlet end and the catalyst runner are compressed and sealed again.

In the working state, the hot gas flow with a temperature of 350-400 °C passes through the gas separation box at the inlet end and enters the thermal regeneration zone, and then flows back to the catalyst regeneration preheating zone through the gas separation at the gas outlet end to form a regeneration hot gas flow, and returns to the catalyst converter. The intake end of the wheel is mixed with the flue gas of the main body, and the flow rate of the regenerated hot air flow is 2-10% of the flue gas flow rate of the main body.

The hot air is mainly heated by electricity or fuel, and the temperature rises to 350-400°C.

The rotary low-temperature SCR denitrification and online continuous regeneration device is applied to the low-temperature denitrification treatment of industrial kiln flue gas including coking, steel sintering, alumina roasting, ceramics and glass firing.

In the present invention, the inner cylinder, the outer shell and the radial partition plate of the catalyst runner are all made of heat-resistant metal materials, and the catalyst runner is manually rotated regularly, driven by motor gears or driven by roller friction. The rotation can just switch a partition unit (that is, the catalyst loading area), and the switching time interval is 1-10 hours, mainly depending on the performance of the catalyst itself and the temperature of the flue gas.

The device of the present invention can be installed vertically or horizontally. The inlet end of the catalyst runner is provided with an injector, which injects the reducing agent used for denitrification and mixes it evenly into the flue gas. The reducing agent is ammonia gas. The SCR catalyst adopted in the present invention has a higher catalyst denitrification activity at a temperature of 150-250°C.

It should be noted that if the catalyst runner itself is kept stationary and the switching mode of rotating the end caps and the air separation box on both sides of the runner is still the same as the present invention, it belongs to the scope of protection of the present invention.

Compared with the prior art, the present invention utilizes a uniquely designed runner device, which can simultaneously complete flue gas low-temperature SCR denitrification treatment and online continuous regeneration of the catalyst, avoiding the catalyst being adsorbed by more harmful components or being covered by ammonium salts, etc. The phenomenon of poisoning or failure caused by the cause greatly improves the service life of the catalyst; at the same time, the regeneration airflow is only a small stream of hot air or the main flue gas heated to 350-400 ℃ by the regeneration airflow heater, and the regeneration preheating airflow That is, the gas flowing out of the thermal regeneration area, after a reflux cycle, makes the regeneration air flow fully utilize the heat of the original flue gas, and the regeneration preheating air flow makes full use of the waste heat of the regeneration air flow, which significantly saves energy consumption; at the same time, it can be used according to different smoke According to the characteristics of gas, it can flexibly adjust the conversion frequency of different areas of the runner.

Description of drawings

Fig. 1 is a schematic diagram of the working principle of the present invention;

Fig. 2 is a schematic diagram of the assembly structure of the catalyst runner;

Fig. 3 is a structural schematic diagram of the intake end of the catalyst runner;

Fig. 4 is a schematic structural view of the outlet end of the catalyst runner;

Fig. 5 is a schematic cross-sectional structure diagram of the gas separation box at the intake end;

Fig. 6 is a schematic cross-sectional structure diagram of the gas separation box at the gas outlet.

In the figure: 1. Regenerated airflow conveying fan, 2. Regenerated airflow heater, 3. The main unit of the runner catalyst, 4-1. The catalyst runner, 4-2. The gas separation box at the inlet end, 4-3. The outlet end Gas separation box, 5. Thermal regeneration zone, 6. Catalyst regeneration preheating zone, 7. Outer shell, 8. Inner cylinder, 9. Radial partition plate, 10. Catalyst loading zone.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example 1:

As shown in FIGS. 1 to 6 , the rotary wheel-type low-temperature SCR denitrification and online continuous regeneration device includes a rotary catalyst main unit 3 , a regenerative airflow conveying fan 1 and a regenerative airflow heater 2 . The main body unit 3 of the runner catalysis comprises a catalyst runner 4-1 which rotates intermittently, and an inlet-end gas separation box 4-2 and an outlet-end gas separation box 4-3 respectively arranged at both ends of the catalyst runner 4-1. The gas separation box 4-2 at the end and the gas separation box 4-3 at the gas outlet jointly isolate the catalyst runner 4-1 into a low-temperature SCR reaction zone, a catalyst regeneration preheating zone 6 and a thermal regeneration zone 5 in the circumferential direction.

Among them, the catalyst runner 4-1 is composed of an inner cylinder 8, an outer shell 7, a radial partition plate 9, a catalyst loading area 10, and corresponding sealing sections. The radial partition plate 9 divides the cavity between the outer shell 7 and the inner cylinder 8 into a plurality of catalyst loading areas 10, and each catalyst loading area 10 is embedded with a corresponding low-temperature SCR catalyst.

The two ends of the catalyst runner 4-1 are respectively provided with an inlet end cover and an outlet end cover, respectively equipped with an inlet end gas separation box 4-2 and an air outlet end gas separation box 4-3, so as to separate the flue gas of the main body from the regeneration The gas flow is separated, thereby separating the catalyst runner 4 - 1 from the low-temperature SCR reaction zone, the catalyst regeneration preheating zone 6 and the thermal regeneration zone 5 in the circumferential direction. The area areas of the catalyst regeneration preheating zone 6 and the thermal regeneration zone 5 are respectively the same as the area area of a partition unit (i.e. the catalyst loading area 10) of the catalyst runner 4-1, and the area area of the low-temperature SCR reaction zone is the same as that of the remaining partition units area is the same.

The regeneration gas flow is 6% coking flue gas heated to 400° C. by the regeneration gas flow heater 2 , and the catalyst regeneration preheated gas flow is the return gas at the gas outlet of the thermal regeneration zone 5 . A mechanical seal is adopted between the catalyst runner 4-1 and the end cover, and the gas separation box 4-2 at the inlet end is installed at the inlet end of the catalyst runner 4-1, covering only one catalyst loading area 10, while the gas outlet at the gas outlet The partition box 4-3 is installed at the gas outlet of the catalyst runner 4-1, and can cover two catalyst loading areas 10 at the same time. The gas separation box 4-2 at the inlet end, the gas separation box 4-3 at the gas outlet end are sealed with the catalyst runner 4-1, and are compressed with springs. When rotation is required, external force is used to pull the sealing surface of the gas separation box away from the section of the catalyst runner 4-1 to prevent wear of the sealing surface. After turning in place, remove the external force to re-press the seal.

The operation principle of this embodiment will be described below:

The coking flue gas with a flow rate of 150000m ³ /h and a temperature of 250°C enters the low-temperature SCR reaction zone of the catalyst runner 4-1 through the inlet end cover, and the regenerative airflow conveying fan 1 extracts 6% of the coking flue gas through the regenerative airflow heater 2 After heating to 400°C, use the gas separation box 4-2 at the inlet end to enter the thermal regeneration zone 5 of the catalyst runner 4-1, and after the regeneration airflow passes through the catalyst runner 4-1, use the gas separation box 4-3 at the gas outlet It flows back to the catalyst regeneration preheating zone 6 to form a regenerated hot gas flow, returns to the inlet end of the catalyst runner 4-1 and mixes with the coking flue gas of the main body, and then enters the low-temperature SCR reaction zone. In this way, coking flue gas denitrification and catalyst continuous regeneration can be realized at the same time.

Example 2:

Using the device in Example 1, the flue gas from glass firing with a flow rate of 100,000 m ³ /h and a temperature of 260°C enters the low-temperature SCR reaction zone of the catalyst runner 4-1 through the inlet end cover, and the regenerative airflow conveying fan 1 extracts 8 % of the flue gas from glass firing is heated to 350°C by the regeneration airflow heater 2, and enters the thermal regeneration zone 5 of the catalyst runner 4-1 through the gas separation box 4-2 at the inlet end, and the regeneration airflow passes through the catalyst runner 4- After 1, use the gas separation box 4-3 at the gas outlet to return to the catalyst regeneration preheating zone 6 to form a regeneration hot gas flow, return to the inlet end of the catalyst runner 4-1 and mix with the coking flue gas of the main body, and then enter the low-temperature SCR reaction Area.

Catalyst runner 4-1 starts to rotate once every half hour, and each time rotates an interval. Before starting to rotate each time, the gas separation boxes at both ends withdraw to the outside through the spring device; after the catalyst runner 4-1 rotates in place and stops rotating, the gas separation boxes at both ends advance through the spring device again, and are connected with the catalyst runner 4-1. 1 seal connection. In this way, coking flue gas denitrification and catalyst continuous regeneration can be realized at the same time.

Example 3:

The rotary wheel-type low-temperature SCR denitrification and online continuous regeneration device in this embodiment includes a rotary catalytic converter main unit 3, a regenerative air flow conveying fan 1 used in conjunction with the rotary catalytic converter main unit 3, a regenerative air flow heater 2, and a rotary catalytic converter main unit 3 includes the catalyst runner 4-1 which rotates intermittently, and the gas separation box 4-2 at the inlet end and the gas separation box 4-3 at the outlet end respectively arranged at both ends of the catalyst runner 4-1, and the gas separation box 4-3 at the inlet end -2. The gas separation box 4-3 at the gas outlet jointly isolates the catalyst runner 4-1 from the low-temperature SCR reaction zone, the catalyst regeneration preheating zone 6 and the thermal regeneration zone 5 in the circumferential direction.

The catalyst runner 4-1 includes an outer casing 7 with open ends and a hollow cavity, an inner cylinder 8 inserted in the outer casing 7, and six radial diameters uniformly arranged between the inner cylinder 8 and the outer casing 7 along the axial direction of the outer casing 7. To the partition plate 9, the two ends of the inner cylinder 8 are sealed, and the sealing surfaces of the partition box are respectively set. The radial partition plate 9 divides the cavity between the outer casing 7 and the inner cylinder 8 into six catalyst loading regions 10 .

One side of the gas separation box 4-2 at the inlet end is provided with a regeneration hot gas flow inlet, and the other side covers a catalyst loading area 10 to form a first thermal regeneration section; one side of the gas separation box 4-3 at the gas outlet end is provided with a regeneration Hot gas flow outlet, the other side covers two adjacent catalyst loading areas 10 at the same time, one of the covered catalyst loading areas 10 forms a second thermal regeneration area connected with the first thermal regeneration area, and the first thermal regeneration area is connected with the first thermal regeneration area The second thermal regeneration zone together forms the thermal regeneration zone 5 , another covered catalyst loading zone 10 forms the catalyst regeneration preheating zone 6 , and the rest uncovered catalyst loading zones 10 together form the low-temperature SCR reaction zone.

Catalyst runner 4-1 two ends are also respectively provided with inlet end cover and outlet end cover that are connected with inlet end gas separation box 4-2, outlet gas separation box 4-3, catalyst runner 4-1 and The inlet end cover and the outlet end cover adopt mechanical seal.

The gas separation box 4-2 at the inlet end, the gas separation box 4-3 at the gas outlet end, and the catalyst runner 4-1 are all compressed by springs. When rotation is required, the sealing surface of the separation box and the catalyst runner 4 The section of -1 is pulled apart to prevent the sealing surface of the separation box from being worn. After the rotation is in place, the external force is removed, so that the gas separation box 4-2 at the inlet end, the gas separation box 4-3 at the gas outlet end and the catalyst runner 4-1 are reconnected. Compress to seal.

In this embodiment, the diameter of the inner cylinder 8 is 400 mm, the inner diameter of the outer shell 7 is 1200 mm, and the effective length of the catalyst runner 4-1 is 2000 mm. The catalyst loading area 10 is filled with a granular SCR catalyst. In the working state, the hot gas with a temperature of 350-400°C enters the thermal regeneration zone 5 through the gas separation box 4-2 at the inlet end, and then flows back to the catalyst regeneration preheating zone 6 through the gas separation box 4-3 at the gas outlet end. A regenerated hot air flow is formed and returned to the intake end of the catalyst runner 4-1 to be mixed with the flue gas of the main body. The flow rate of the hot regenerated air flow is 2-10% of the flow rate of the flue gas of the main body.

The wheel-type low-temperature SCR denitrification and online continuous regeneration device in this embodiment is applied to the low-temperature denitrification treatment of industrial kiln flue gas including coking, steel sintering, alumina roasting, ceramics and glass firing.

Example 4:

In this embodiment, there are 15 radial partition plates 9 in total, the diameter of the inner cylinder 8 is 1200 mm, the inner diameter of the outer shell 7 is 5000 mm, and the effective length of the catalyst runner 4-1 is 4000 mm. The catalyst loading area 10 is filled with a honeycomb SCR catalyst. All the other are with embodiment 3.

Example 5:

In this embodiment, there are 12 radial partition plates 9 in total, the diameter of the inner cylinder 8 is 600 mm, the inner diameter of the outer shell 7 is 2400 mm, and the effective length of the catalyst runner 4-1 is 2500 mm. The catalyst loading area 10 is filled with a corrugated SCR catalyst. All the other are with embodiment 3.

Embodiment 6:

In this embodiment, there are two radial partition plates 9, the inner cylinder 8 has a diameter of 800 mm, the outer shell 7 has an inner diameter of 3600 mm, and the effective length of the catalyst runner 4-1 is 3000 mm. The catalyst loading area 10 is filled with granular SCR catalysts, honeycomb SCR catalysts and corrugated plate SCR catalysts. All the other are with embodiment 3.

The above descriptions of the embodiments are for those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described here to other embodiments without creative effort. Therefore, the present invention is not limited to the above-mentioned embodiments. Improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims (7)

1. rotary-type low temperature SCR denitration and on-line continuous regenerating unit, which is characterized in that the device includes runner catalyst body list First (3) and regeneration air stream conveying fan (1), the regeneration air stream heater being used cooperatively with runner catalyst body unit (3) (2), the runner catalyst body unit (3) includes the catalyst runner (4-1) of intermittent rotary and is separately positioned on catalysis The inlet end gas partitions case (4-2) and outlet side gas partitions case (4-3) at the both ends agent runner (4-1), the inlet end gas Body separation case (4-2), outlet side gas partitions case (4-3) jointly isolate catalyst runner (4-1) low in a circumferential direction Warm SCR reaction zone, catalyst regeneration pre-add hot-zone (6) and hot recycling area (5)；

The catalyst runner (4-1) includes both ends open and has the shell (7) of hollow cavity, is plugged in shell (7) Inner cylinder (8) and N number of along the axial uniformly distributed radial separations plate (9) between inner cylinder (8) and shell (7) of shell (7), In, N is integer, and N >=2, the sealing of the inner cylinder (8) both ends, and separation case sealing surface is respectively set；

Cavity between shell (7) and inner cylinder (8) is separated into N number of catalyst loading area (10) by the radial separations plate (9), N is integer, and N >=2；

The side of the inlet end gas partitions case (4-2) is equipped with regenerated heat airflow inlet, and the other side covers a catalyst Loading area (10) forms the first hot recycling section；The side of the outlet side gas partitions case (4-3) is equipped with regeneration thermal current Outlet, the other side cover two neighboring catalyst loading area (10) simultaneously, one of them capped catalyst loading area (10) Form the second hot recycling section being connected with the first hot recycling section, and the first hot recycling section and the second hot recycling section Hot recycling area (5) are collectively formed, another capped catalyst loading area (10) then forms catalyst regeneration pre-add hot-zone (6), and remaining uncovered catalyst loading area (10) collectively forms low-temperature SCR reaction zone.

2. rotary-type low temperature SCR denitration according to claim 1 and on-line continuous regenerating unit, which is characterized in that described Catalyst loading area (10) in be filled with graininess SCR catalyst, honeycomb-shaped SCR catalyst or corrugated plate shape SCR catalyst One of or it is a variety of.

3. rotary-type low temperature SCR denitration according to claim 1 and on-line continuous regenerating unit, which is characterized in that described The diameter of inner cylinder (8) be 400-1200mm, the internal diameter of the shell (7) is 1200-5000mm, the catalyst runner The effective length of (4-1) is 2000-4000mm.

4. rotary-type low temperature SCR denitration according to any one of claims 2 to 3 and on-line continuous regenerating unit, feature It is, described both ends catalyst runner (4-1) further respectively have and inlet end gas partitions case (4-2), outlet side gas point The air inlet end cap and outlet end cap that cell (4-3) is connected, the catalyst runner (4-1) and air inlet end cap, outlet end cap Using mechanical seal.

5. rotary-type low temperature SCR denitration according to claim 4 and on-line continuous regenerating unit, which is characterized in that described Inlet end gas partitions case (4-2), between outlet side gas partitions case (4-3) and catalyst runner (4-1) be all made of spring It compresses, when needing to rotate, separation case sealing surface and the section of catalyst runner (4-1) is pulled open using external force, prevent from separating Case sealing surface wear, after rotateing in place, removal external force makes inlet end gas partitions case (4-2), outlet side gas partitions case (4-3) and catalyst runner (4-1) is compressed again and is sealed.

6. rotary-type low temperature SCR denitration according to claim 4 and on-line continuous regenerating unit, which is characterized in that in work Make under state, the hot gas that temperature is 350-400 DEG C is flowed through into inlet end gas partitions case (4-2) into hot recycling area (5), then pass through Outlet side gas partitions case (4-3) is back to catalyst regeneration pre-add hot-zone (6), forms regeneration thermal current, is back to catalyst The inlet end of runner (4-1) is mixed with main body flue gas, the 2-10% of flue gas flow based on the flow of the regeneration thermal current.

7. the application of rotary-type low temperature SCR denitration as described in claim 1 and on-line continuous regenerating unit, which is characterized in that For including the low-temperature denitration processing of the industrial furnace smokes such as coking, steel sintering, aluminium oxide calcining, ceramics and glass firing.