CN216878657U

CN216878657U - SNCR (selective non-catalytic reduction) denitration system taking urea as reducing agent

Info

Publication number: CN216878657U
Application number: CN202220240719.2U
Authority: CN
Inventors: 侯超; 王勋; 颜利民
Original assignee: Puxiang Bioenergy Co ltd
Current assignee: Puxiang Bioenergy Co ltd
Priority date: 2022-01-28
Filing date: 2022-01-28
Publication date: 2022-07-05
Anticipated expiration: 2032-01-28

Abstract

The utility model discloses an SNCR (selective non-catalytic reduction) denitration system taking urea as a reducing agent, which comprises a preparation tank, a storage tank, a vacuum feeding device and a first water inlet pipe connected with a deaerator, wherein the preparation tank is connected with the storage tank; the first water inlet pipe and the vacuum feeding device are respectively connected with the preparation tank and used for inputting water and solid urea; the preparation tank and the storage tank are internally provided with an electric tracing band, a stirring device and a liquid level meter; the liquid outlet pipeline at the bottom of the preparation tank comprises a first branch a and a second branch b, the second branch b is connected with the incinerator, urea solution is conveyed into the incinerator to carry out denitration reaction with flue gas, the first branch a is connected with the storage tank, and the urea solution is conveyed into the storage tank; the storage tank bottom is equipped with the drain pipe way of being connected with burning furnace, carries urea solution to burning in the burning furnace and carries out denitration reaction with the flue gas. The urea solution preparation and storage stability is effectively improved, and the operation stability of a waste incineration system is improved.

Description

SNCR (selective non-catalytic reduction) denitration system taking urea as reducing agent

Technical Field

The utility model belongs to the technical field of flue gas denitration, and particularly relates to an SNCR (selective non-catalytic reduction) denitration system taking urea as a reducing agent.

Background

With the acceleration of the urbanization process, the daily quantity of domestic garbage generated in cities is more and more huge, the traditional treatment modes such as landfill and the like cannot be continued, how to scientifically and reasonably comprehensively treat and utilize the garbage becomes an increasingly important subject, and harmlessness, reduction and recycling become common knowledge. Among them, the high-temperature incineration is carried out to the rubbish that the burning value is higher, utilizes the heat that the incineration rubbish produced to heat and produces steam, and steam gets into the steam turbine and generates electricity, obtains more and more extensive application in practice.

Selective non-catalytic reduction (selective non-catalytic reduction) refers to the reduction of nitrogen oxides in flue gas into harmless nitrogen and water by injecting a reducing agent in a temperature window suitable for denitration reaction without the action of a catalyst. For the municipal refuse incinerator, urea is mostly sprayed into the incinerator as a reducing agent, the reducing agent only reacts with NOx in flue gas, and generally does not react with oxygen, and a selective non-catalytic reduction method (SNCR) is called because a catalyst is not adopted. Since the process does not use a catalyst, the reducing agent must be added in the high temperature zone. And spraying the reducing agent into a region with the hearth temperature of 850-1100 ℃, quickly thermally decomposing into ammonia gas, and reacting with NOx in the flue gas to generate nitrogen and water.

The SNCR denitration system firstly needs to prepare a urea solution, and is traditionally carried out by an operator. The drawbacks of this approach mainly include: 1. the working intensity of operators is high, the feeding amount or the water adding amount is not strict easily, and the concentration of the prepared solution fluctuates; 2. the workman directly emptys urea to open urea solution preparation jar easily, and falls into the dust easily, and deposit easily at the tank bottoms end for a long time, blocks up pipeline. 3. The urea particles are dissolved by tap water, a relatively long time is needed, and after the urea particles are heated, temporary hardness is separated out, scales are formed on the inner wall of the pipeline, and the pipeline can be blocked in serious cases. 4. Urea solution is easy to crystallize on the inner wall of the pipeline, so that the pipe diameter is reduced, blockage can be caused if the pipe is not cleaned in time, and the pipe is difficult to dredge once the blockage occurs.

In addition, although the prior art mentions that the prepared urea solution is stored in a storage tank, the stirring device of the prior urea solution storage tank has low stirring efficiency and large energy consumption, and has poor storage effect on the urea solution. In addition, in the operation process, the stirring device also has the problem of overlarge vibration, which causes the vibration of the shell of the storage tank and causes adverse effects on the field safe operation.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects of the prior art and provide the SNCR denitration system which has the advantages of compact structure, simple operation, low labor intensity, high preparation and storage stability of urea solution and takes urea as a reducing agent.

In order to solve the technical problems, the utility model adopts the following technical scheme:

an SNCR denitration system using urea as a reducing agent comprises: the device comprises a preparation tank, a storage tank, a vacuum feeding device and a first water inlet pipe connected with a deaerator; the first water inlet pipe and the vacuum feeding device are respectively connected with the preparation tank and used for realizing automatic water and solid urea input; the preparation tank is internally provided with a first electric tracing band, a first stirring device and a first liquid level meter, wherein the first stirring device is used for uniformly mixing water and solid urea to obtain a urea solution, the first electric tracing band is used for heating the urea solution, and the first liquid level meter is used for metering the volume of the urea solution; the bottom of the preparation tank is provided with a liquid outlet pipeline, the liquid outlet pipeline comprises a first branch a and a second branch b which are arranged in parallel, the second branch b is connected with the incinerator and used for conveying the urea solution into the incinerator to perform denitration reaction with flue gas, and the first branch a is connected with the storage tank and used for conveying the urea solution into the storage tank; a second electric tracing band, a second stirring device and a second liquid level meter are arranged inside the storage tank, the second stirring device is used for uniformly stirring the urea solution, the second electric tracing band is used for heating the urea solution, and the second liquid level meter is used for measuring the volume of the urea solution; the bottom of the storage tank is provided with a liquid outlet pipeline, and the liquid outlet pipeline is connected with the incinerator and used for conveying the urea solution into the incinerator to perform denitration reaction with the flue gas.

As a further improvement of the utility model, the second branch b and the liquid outlet pipeline at the bottom of the storage tank are combined to a liquid outlet main pipeline c, and a third filter is arranged on the liquid outlet main pipeline c and is used for filtering the urea solution entering the incinerator.

As a further improvement of the utility model, two groups of pumping branches are connected in parallel to the first branch a, and a filter for filtering the urea solution, a delivery pump for delivering the urea solution and a check valve for preventing the urea solution from flowing back are arranged on the pumping branches.

As a further improvement of the utility model, the preparation tank and the storage tank are respectively provided with an emptying valve, an overflow port and a sewage draining outlet.

As a further improvement of the utility model, the second stirring device comprises a spiral stirring paddle for realizing uniform stirring of the urea solution.

As a further improvement of the utility model, the stirring device further comprises a vibration damping assembly which is fixed inside the storage tank and is positioned at the middle lower part of the stirring rod and used for preventing the stirring rod from shaking.

As a further improvement of the present invention, the vibration damping assembly includes a first vibration damping member and a second vibration damping member, the first vibration damping member is sleeved outside the stirring rod, the second vibration damping member is sleeved outside the first vibration damping member, and the first vibration damping member and the stirring rod are in clearance fit.

As a further improvement of the utility model, the first vibration damping component and the second vibration damping component are both in a semi-cylindrical structure, a groove is arranged on the outer side of the first vibration damping component, connecting lugs are respectively arranged on two sides of the second vibration damping component, and connecting holes are arranged on the connecting lugs; the second vibration reduction component is sleeved outside the groove, and the connecting hole is used for fixing the second vibration reduction component outside the first vibration reduction component.

As a further improvement of the utility model, the vacuum feeding device comprises a feeding tank, a vacuum feeding machine and a vacuum pump; the vacuum pump is connected with the top of the charging bucket and is used for realizing the vacuum pumping inside the charging bucket; the vacuum feeding machine is connected with the upper part of the feeding tank and is used for conveying solid urea into the feeding tank; the bottom of the feeding tank is connected with the top of the preparation tank and used for conveying the solid urea to the preparation tank.

As a further improvement of the utility model, the system also comprises a second water inlet pipe for conveying the desalted water, wherein the second water inlet pipe comprises a water inlet branch d and a water inlet branch e; the first water inlet branch d is connected with the preparation tank and used for conveying desalted water into the preparation tank; and the water inlet branch circuit two e is connected with the first branch circuit a and is used for conveying desalted water to the first branch circuit a.

Compared with the prior art, the utility model has the advantages that:

1. according to the SNCR denitration system using urea as a reducing agent, the vacuum feeding device and the first water inlet pipe are connected with the configuration tank 1, so that automatic feeding of water and solid urea is realized, the labor intensity of operators is effectively reduced, and the feeding accuracy is favorably controlled; the electric tracing band, the stirring device and the liquid level meter are arranged in the preparation tank and the storage tank, so that the urea solution is uniformly stirred, the urea solution is kept at a certain temperature, the phenomenon of urea crystallization is avoided, the capacity of the urea solution in the tank is monitored, the preparation, storage and conveying stability of the urea solution is greatly improved, and the working efficiency of a denitration system is improved; further, through set up parallelly connected first branch road an and second branch road b on the drain pipe that prepares tank bottoms portion to set up, the urea solution that comes out from preparing the jar not only can go to the holding vessel through first branch road a, can also directly go to in the incinerator and carry out denitration reaction with the flue gas through second branch road b, has both improved urea solution's use flexibility, has also improved SNCR deNOx systems continuous operation's stability.

2. According to the SNCR denitration system using urea as a reducing agent, the filters are arranged on the liquid outlet main pipeline c and the first branch pipeline a, and the urea solution entering the storage tank or the incinerator is filtered by the filters, so that the purity of the urea solution is improved, solid particle impurities in the urea solution are effectively prevented from entering the incinerator to damage spraying equipment, the use stability of the spraying equipment is improved, and the quality of flue gas denitration is improved.

3. According to the SNCR denitration system using urea as a reducing agent, the stirring paddle of the second stirring device is set to be the spiral stirring paddle similar to the spring structure, the urea solution at the bottom of the storage tank is stirred more fully by the spiral stirring paddle with the larger lower part and the smaller upper part, and urea crystals are effectively prevented from being deposited at the bottom of the storage tank; furthermore, the spiral stirring paddle can be prepared from tough steel, and the inertia force is transmitted to a longer distance under the action of the tough steel, so that the stirring device is more energy-saving.

4. According to the SNCR denitration system using urea as a reducing agent, the vibration reduction assembly is arranged in the storage tank and is positioned at the middle lower part of the stirring rod, and the stirring rod is limited by the vibration reduction assembly, so that the stirring rod is effectively prevented from shaking in the operation process, and the use safety of the storage tank is improved.

5. According to the SNCR denitration system using urea as a reducing agent, the air in the feeding tank is sucked by using the vacuum pump, so that the pressure in the feeding tank is reduced, the pressure of the vacuum feeding machine connected with the feeding tank is increased, the solid urea in the vacuum feeding machine smoothly enters the feeding tank, the automatic feeding of the solid urea is realized, and the labor intensity of manpower is greatly reduced.

Drawings

FIG. 1 is a schematic structural diagram of an SNCR denitration system using urea as a reducing agent according to the present invention.

Fig. 2 is a schematic front view of the first vibration damping member according to the present invention.

Fig. 3 is a schematic top view of the first damping member according to the present invention.

Fig. 4 is a schematic side view of the first vibration damping member according to the present invention.

Fig. 5 is a schematic front view of the second vibration damping member according to the present invention.

Fig. 6 is a schematic top view of the second damping member according to the present invention.

Fig. 7 is a schematic side view of the second vibration damping member according to the present invention.

Illustration of the drawings: 1. preparing a tank; 2. a storage tank; 3. feeding the material tank; 4. a vacuum feeding machine; 5. a first water inlet pipe; 6. a second water inlet pipe; 7. a vacuum pump; 8. a first valve; 9. a second valve; 10. a third valve; 11. a fourth valve; 12. a fifth valve; 13. a sixth valve; 14. a seventh valve; 15. a first overflow port; 16. a first electric tracing band; 17. a first drain port; 18. a first stirring device; 19. an eighth valve; 20. a ninth valve; 21. a tenth valve; 22. an eleventh valve; 23. a first liquid level meter; 24. a twelfth valve; 25. a first purge valve; 26. a twelfth valve; 27. a thirteenth valve; 28. a fourteenth valve; 29. a first filter; 30. a first delivery pump; 31. a first check valve; 32. a fifteenth valve; 33. a sixteenth valve; 34. a second filter; 35. a second delivery pump; 36. a second check valve; 37. a seventeenth valve; 38. a vibration reduction assembly; 381. a first vibration damping member; 3811. a groove; 382. a second vibration damping member; 3821. connecting lugs; 3822. connecting holes; 39. a second electric tracing band; 40. a second stirring device; 41. a second overflow port; 42. a second purge valve; 43. an eighteenth valve; 44. a second level gauge; 45. a nineteenth valve; 46. a third filter; 47. a twentieth valve; 48. a twenty-first valve; 49. a second twelve-valve; 50. a twenty-third valve; 51. a twenty-fourth valve; 52. a second sewage draining outlet; 53. a helical stirring paddle; 54. a stirring rod; a. a first branch; b. a second branch circuit; c. a liquid outlet main pipeline; d. a water inlet branch I; e. and a water inlet branch II.

Detailed Description

The utility model is further described below with reference to the drawings and the specific preferred embodiments, without thereby limiting the scope of protection of the utility model.

Examples

As shown in fig. 1 to 7, the SNCR denitration system using urea as a reducing agent according to the present invention includes: the system comprises a preparation tank 1, a storage tank 2, a vacuum feeding device and a first water inlet pipe 5 connected with a deaerator water balance pipe. In order to improve the usability of the apparatus, the preparation tank 1 and the storage tank 2 may be made of 304 stainless steel having good corrosion resistance, heat resistance, low-temperature strength, and mechanical properties. The first water inlet pipe 5 and the vacuum feeding device are respectively connected with the preparation tank 1 and used for realizing automatic water and solid urea input. Specifically, a third valve 10, a fifth valve 12 and a seventh valve 14 are sequentially arranged on the first water inlet pipe 5; the fifth valve 12 is a water inlet regulating valve, is connected with a control system and can be automatically opened and closed; the third valve 10 and the seventh valve 14 are respectively a front isolation valve and a rear isolation valve of the water inlet regulating valve, and when the fifth valve 12 needs to be overhauled and maintained, the third valve 10 and the seventh valve 14 are respectively closed, so that the fifth valve 12 is isolated from the water inlet pipe, and the overhauling effect is improved. It can be understood that the hot water delivered from the water balance pipe of the deaerator can reach about 130 ℃, and the dissolving effect of the solid urea can be greatly improved by utilizing the hot water.

The preparation tank 1 is internally provided with a first electric tracing band 16, a first stirring device 18 and a first liquid level meter 23; the first stirring device 18 is used for uniformly mixing hot water and solid urea to obtain a urea solution with the concentration of 40%; the first electric tracing band 16 is used for heating the urea solution, so that the urea solution is kept in a certain temperature range, and the phenomenon that the pipeline is blocked due to the precipitation of urea crystals is avoided; the first level gauge 23 is used for measuring the volume of the urea solution so that an operator can grasp the urea solution storage amount in the preparation tank 1 in real time. It is understood that the first electric tracing band 16 and the first stirring device 18 are conventional devices, the first liquid level meter 23 can be a magnetic turning plate liquid level meter, and an eighth valve 19 and a twelfth valve 24 are respectively arranged at the lower part and the upper part of the liquid level meter, and the urea solution is filled into the liquid level meter by opening the two valves, so that the urea solution storage amount in the preparation tank 1 can be read.

The bottom of the preparation tank 1 is provided with a liquid outlet pipeline, the liquid outlet pipeline comprises a first branch a and a second branch b which are arranged in parallel, the second branch b is connected with the incinerator and used for conveying urea solution into the incinerator and carrying out denitration reaction with flue gas, and the first branch a is connected with the storage tank 2 and used for conveying the urea solution into the storage tank 2. Namely, the prepared urea solution in the preparation tank 1 can be directly fed into the incinerator for reaction, and can also be conveyed into the storage tank 2 for storage and standby. Specifically, a ninth valve 20 is arranged on a liquid outlet pipeline at the bottom of the preparation tank 1, and liquid outlet of the preparation tank 1 is controlled through the ninth valve 20; an eleventh valve 22 is arranged on the first branch a, and the flow of the urea solution in the first branch a is adjusted through the eleventh valve 22; a tenth valve 21 and a twenty-third valve 50 are arranged on the second branch b, and the on-off of the second branch b is controlled by the tenth valve 21 and the twenty-third valve 50.

A second electric tracing band 39, a second stirring device 40 and a second liquid level meter 44 are arranged inside the storage tank 2, the second stirring device 40 is used for realizing uniform stirring of the urea solution, and the second electric tracing band 39 is used for realizing heating of the urea solution, so that the urea solution is kept in a certain temperature range, and the phenomenon of urea crystallization is avoided; the second level meter 44 is used for measuring the volume of the urea solution so that an operator can grasp the urea solution storage amount in the storage tank 2 in real time. It is understood that the second electric tracing band 39 and the second stirring device 40 are conventional devices, the second level gauge 44 may be a magnetic turn plate level gauge, and an eighteenth valve 43 and a twenty-fourth valve 51 are respectively provided at the lower portion and the upper portion of the level gauge, and the urea solution is filled into the level gauge by opening the two valves, so that the urea solution storage amount in the storage tank 2 can be read. 2 bottoms of holding vessel are equipped with out the liquid pipeline, go out the liquid pipeline and be connected with burning furnace for carry urea solution to burning furnace in with the flue gas carry out denitration reaction.

In the embodiment, the vacuum feeding device and the first water inlet pipe 5 are connected with the configuration tank 1, so that the automatic feeding of water and solid urea is realized, the labor intensity of operators is effectively reduced, and the feeding accuracy is controlled; the electric tracing band, the stirring device and the liquid level meter are arranged in the preparation tank 1 and the storage tank 2, so that the urea solution is uniformly stirred, the urea solution is kept at a certain temperature, the phenomenon of urea crystallization is avoided, the capacity of the urea solution in the tanks is monitored, the preparation, storage and conveying stability of the urea solution is greatly improved, and the working efficiency of a denitration system is improved; further, through set up parallelly connected first branch road an and second branch road b on the drain pipe that sets up 1 bottom of preparation jar, the urea solution that goes out from preparation jar 1 not only can go to holding vessel 2 through first branch road a, can also directly go to in the incinerator and carry out denitration reaction with the flue gas through second branch road b, has both improved urea solution's use flexibility, has also improved SNCR deNOx systems continuous operation's stability.

In this embodiment, the second branch b and the liquid outlet pipe at the bottom of the storage tank 2 are merged to a liquid outlet main pipe c, a third filter 46 is disposed on the liquid outlet main pipe c, and the third filter 46 is used for filtering the urea solution entering the incinerator. Specifically, a liquid outlet pipeline at the bottom of the storage tank 2 is provided with a twentieth valve 49, and liquid drainage of the storage tank 2 is controlled through the twenty-second valve 49; the nineteenth valve 45 and the twenty-first valve 48 of the isolation valve are respectively arranged at two ends of the third filter 46, and when the third filter 46 needs to be overhauled and maintained, the nineteenth valve 45 and the twenty-first valve 48 are respectively closed, so that the isolation of the third filter 46 and the liquid outlet main pipeline c can be realized, and the overhauling effect is improved. Meanwhile, another pipeline connected with the pipeline where the third filter 46 is located in parallel is further arranged on the liquid outlet main pipeline c, the twentieth valve 47 is arranged on the pipeline, when the third filter 46 needs to be overhauled and maintained, the twentieth valve 47 is opened, the urea solution can be conveyed into the incinerator, and the stability of continuous operation of the SNCR denitration system is improved.

In this embodiment, two sets of pumping branches are connected in parallel to the first branch a, and a filter for filtering the urea solution, a delivery pump for delivering the urea solution, and a check valve for preventing the urea solution from flowing back are disposed on the pumping branch. Specifically, a fourteenth valve 28, a first filter 29, a first delivery pump 30, a first check valve 31 and a fifteenth valve 32 are sequentially arranged on the first group of pumping branches, the fourteenth valve 28 and the fifteenth valve 32 are front and rear isolation valves of the first group of pumping branches, and when the first group of pumping branches need to be repaired and maintained, the first group of pumping branches can be isolated from the first branch a by closing the fourteenth valve 28 and the fifteenth valve 32. And a sixteenth valve 33, a second filter 34, a second delivery pump 35, a second check valve 36 and a seventeenth valve 37 are sequentially arranged on the second group of pumping branches, the sixteenth valve 33 and the seventeenth valve 37 are used for isolating the front and the rear of the second group of pumping branches, and when the second group of pumping branches need to be overhauled and maintained, the sixteenth valve 33 and the seventeenth valve 37 are closed, so that the second group of pumping branches can be isolated from the first branch a. Two groups of pumping branches connected in parallel are arranged, one pumping branch can be used for standby, and the continuous and stable operation of the system is favorably realized.

In this embodiment, through all having set up the filter on liquid main line c and first branch road an, utilize the filter to filter the urea solution that gets into in holding vessel 2 or the incinerator, improved the purity of urea solution, effectively avoided the solid particle impurity among the urea solution to get into the incinerator and damage spray equipment, improved spray equipment's stability in use, just also improved flue gas denitration's quality.

In this embodiment, all be equipped with exhaust valve, overflow mouth and drain on preparation jar 1 and the holding vessel 2 to improve the operational reliability of preparation jar 1 and holding vessel 2. Specifically, a first evacuation valve 25 is arranged at the top of the preparation tank 1 and used for exhausting air inside the preparation tank 1; a first overflow port 15 is arranged at the side part of the preparation tank 1 and used for discharging redundant urea solution in the preparation tank 1; be equipped with first drain 17 in preparation jar 1 bottom, when needing to overhaul the maintenance, the first drain 17 of accessible will prepare jar 1 evacuation. A second evacuation valve 42 is provided at the top of the storage tank 2 for evacuating the air inside the storage tank 2; a second overflow port 41 is arranged on the side of the storage tank 2 and used for discharging the redundant urea solution in the storage tank 2; the bottom of the storage tank 2 is provided with a second sewage draining outlet 52, so that the storage tank 2 can be drained through the first sewage draining outlet 17 when maintenance is needed.

In this embodiment, the second stirring device 40 includes a helical stirring paddle 53 for uniformly stirring the urea solution. Specifically, the helical paddles 53 are provided in a spring-like gradually expanding configuration, and the material for the preparation is ductile steel. Because the density of the urea is higher than that of water, if the urea is deposited, the urea can be deposited at the bottom of the tank body, the spiral stirring paddle 53 is designed into a structural form with a small upper part and a big lower part, the urea at the lower part of the tank body can be stirred, and the inertia force can be transmitted to a longer distance by utilizing the action of the ductile steel, so that the urea solution can be uniformly stirred; at the same time, the form of the stirrer arranged in this way is also more energy-saving.

In this embodiment, the vibration damping assembly 38 is further included, and the vibration damping assembly 38 is fixed inside the storage tank 2 and located at the middle lower part of the stirring rod 54, so as to prevent the stirring rod 54 from shaking, thereby improving the use safety of the storage tank 2. It is understood that the damping member 38 may be fixed inside the storage tank 2 by a bracket assembly, and the damping member 38 may be made of a metal material having excellent corrosion resistance.

Further, the vibration damping assembly 38 includes a first vibration damping member 381 and a second vibration damping member 382, the first vibration damping member 381 is sleeved outside the stirring rod 54, the second vibration damping member 382 is sleeved outside the first vibration damping member 381, and the first vibration damping member 381 and the stirring rod 54 are in clearance fit. Specifically, a gap of 3mm exists between the first vibration damping member 381 and the stirring rod 54, and rolling friction exists between the first vibration damping member 381 and the stirring rod 54. Through the mode of establishing layer upon layer, both easy to assemble dismantlement also can provide better supplementary limiting displacement simultaneously, avoid puddler 54 to take place to rock violently and influence the safety in utilization of holding vessel 2 in the operation.

As shown in fig. 2 to 7, in the present embodiment, the first vibration damping member 381 and the second vibration damping member 382 are both semi-cylindrical structures, a groove 3811 is provided on the outer side of the first vibration damping member 381, two sides of the second vibration damping member 382 are respectively provided with a connecting ear 3821, and a connecting hole 3822 is provided on the connecting ear 3821; the second damping member 382 is sleeved outside the groove 3811, and the connecting hole 3822 is used for fixing the second damping member 382 outside the first damping member 381. Specifically, during installation, the two first vibration damping members 381 are symmetrically sleeved on the outer side of the stirring rod 54, the two second vibration damping members 382 are respectively and symmetrically sleeved in the two grooves 3811, and a bolt assembly penetrates through the aligned connecting holes 3822, so that the two second vibration damping members 382 are fixedly connected, that is, the vibration damping assembly 38 is fixed on the outer side of the stirring rod 54.

In this embodiment, the vacuum feeding device includes a feeding tank 3, a vacuum feeder 4, and a vacuum pump 7. The vacuum pump 7 is connected with the top of the feeding tank 3 and is used for realizing the vacuum pumping inside the feeding tank 3. The vacuum feeding machine 4 is connected with the upper part of the feeding tank 3 and is used for conveying solid urea into the feeding tank 3. The bottom of the feeding tank 3 is connected with the top of the preparation tank 1 and is used for conveying solid urea into the preparation tank 1; furthermore, a thirteenth valve 27 is arranged between the feeding tank 3 and the preparation tank 1, the thirteenth valve 27 is connected with the control system, and the feeding tank 3 is controlled to automatically discharge through the thirteenth valve 27. Through utilizing vacuum pump 7 to suck the air in material loading bucket 3 for pressure among the material loading bucket 3 diminishes, and the pressure of the vacuum material loading machine 4 that links to each other with material loading bucket 3 then increases, makes the solid urea among the vacuum material loading machine 4 get into material loading bucket 3 smoothly, has realized solid urea automatic feeding, greatly reduced human labor intensity.

In this embodiment, the system further comprises a second water inlet pipe 6 for conveying demineralized water, wherein the second water inlet pipe 6 comprises a first water inlet branch d and a second water inlet branch e; the first water inlet branch d is connected with the preparation tank 1 and used for conveying desalted water into the preparation tank 1; and the water inlet branch e is connected with the first branch a and used for conveying the desalted water to the first branch a. The demineralized water is cold water and is generally reserved. Furthermore, a first valve 8 is arranged on the second water inlet pipe 6, and the on-off of the second water inlet pipe 6 is controlled through the first valve 8. The first water inlet branch d is sequentially provided with a second valve 9, a fourth valve 11 and a sixth valve 13, the second valve 9 and the sixth valve 13 are front and rear isolation valves of the first water inlet branch d, and when the first water inlet branch d needs to be overhauled, the second valve 9 and the sixth valve 13 are closed, so that the first water inlet branch d can be isolated from the second water inlet pipe 6; the fourth valve 11 is used for adjusting the opening degree of the water inlet branch d, and the fourth valve 11 is connected with the control system to realize automatic water supply of the water inlet branch d. A twelfth valve 26 is arranged on the water inlet branch line two e, and the twelfth valve 26 is used for controlling the on-off of the water inlet branch line two e. When the first branch a needs to be flushed for maintenance, the twelfth valve 26 is opened to convey the demineralized water to the first branch a, so that convenience and reliability are realized.

The working process comprises the following steps:

the bagged urea is firstly put into the preparation tank 1 by a vacuum feeding device, and then quantitative normal-temperature desalted water or hot water with the temperature of about 130 ℃ from a deaerator water balance pipe is injected into the preparation tank 1. During urea blending, the urea is directly poured into the vacuum feeding machine 4 by manual bag removal, and then is loaded into the blending tank 1 by the vacuum feeding device. The prepared urea solution with the concentration of 40% is conveyed to a storage tank 2 from a preparation tank 1. Specifically, one path of the urea solution from the preparation tank 1 flows to the storage tank 2 for standby, and the other path of the urea solution directly flows into the incinerator for denitration.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make many possible variations and modifications to the disclosed embodiments, or equivalent modifications, without departing from the spirit and scope of the utility model, using the methods and techniques disclosed above. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the scope of the protection of the technical solution of the present invention.

Claims

1. An SNCR denitration system using urea as a reducing agent, comprising: the device comprises a preparation tank (1), a storage tank (2), a vacuum feeding device and a first water inlet pipe (5) connected with a deaerator; the first water inlet pipe (5) and the vacuum feeding device are respectively connected with the preparation tank (1) and are used for realizing automatic water and solid urea input; a first electric tracing band (16), a first stirring device (18) and a first liquid level meter (23) are arranged inside the preparation tank (1), the first stirring device (18) is used for uniformly mixing water and solid urea to obtain a urea solution, the first electric tracing band (16) is used for heating the urea solution, and the first liquid level meter (23) is used for metering the volume of the urea solution; a liquid outlet pipeline is arranged at the bottom of the preparation tank (1), the liquid outlet pipeline comprises a first branch a and a second branch b which are arranged in parallel, the second branch b is connected with the incinerator and used for conveying the urea solution into the incinerator to perform denitration reaction with the flue gas, and the first branch a is connected with the storage tank (2) and used for conveying the urea solution into the storage tank (2); a second electric tracing band (39), a second stirring device (40) and a second liquid level meter (44) are arranged inside the storage tank (2), the second stirring device (40) is used for uniformly stirring the urea solution, the second electric tracing band (39) is used for heating the urea solution, and the second liquid level meter (44) is used for metering the volume of the urea solution; and a liquid outlet pipeline is arranged at the bottom of the storage tank (2), and the liquid outlet pipeline is connected with the incinerator and used for conveying the urea solution into the incinerator to perform denitration reaction with the flue gas.

2. The SNCR denitration system using urea as a reducing agent according to claim 1, wherein the second branch b and a liquid outlet pipeline at the bottom of the storage tank (2) are merged into a liquid outlet main pipeline c, a third filter (46) is arranged on the liquid outlet main pipeline c, and the third filter (46) is used for filtering urea solution entering the incinerator.

3. The SNCR denitration system using urea as a reducing agent according to claim 1, wherein the first branch a is provided with two groups of pumping branches in parallel, and the pumping branches are provided with a filter for filtering urea solution, a delivery pump for delivering urea solution and a check valve for preventing urea solution from flowing back.

4. The SNCR denitration system using urea as a reducing agent according to claim 1, wherein an emptying valve, an overflow port and a drain outlet are arranged on each of the preparation tank (1) and the storage tank (2).

5. The SNCR denitration system using urea as a reducing agent according to any one of claims 1 to 4, wherein the second stirring device (40) comprises a spiral stirring paddle (53) for realizing uniform stirring of the urea solution.

6. An SNCR denitration system using urea as a reducing agent according to any one of claims 1 to 4, further comprising a vibration damping member (38), wherein the vibration damping member (38) is fixed inside the storage tank (2) and is located at the middle lower part of the stirring rod (54) for preventing the stirring rod (54) from shaking.

7. An SNCR denitration system using urea as a reducing agent according to claim 6, wherein the vibration damping assembly (38) comprises a first vibration damping member (381) and a second vibration damping member (382), the first vibration damping member (381) is sleeved outside the stirring rod (54), the second vibration damping member (382) is sleeved outside the first vibration damping member (381), and the first vibration damping member (381) and the stirring rod (54) are in clearance fit.

8. An SNCR denitration system using urea as a reducing agent according to claim 7, wherein the first damping part (381) and the second damping part (382) are both semi-cylindrical structures, a groove (3811) is arranged on the outer side of the first damping part (381), two sides of the second damping part (382) are respectively provided with a connecting lug (3821), and a connecting hole (3822) is arranged on each connecting lug (3821); the second vibration reduction component (382) is sleeved outside the groove (3811), and the connecting hole (3822) is used for fixing the second vibration reduction component (382) outside the first vibration reduction component (381).

9. The SNCR denitration system using urea as a reducing agent according to any one of claims 1 to 4, wherein the vacuum feeding device comprises a feeding tank (3), a vacuum feeder (4) and a vacuum pump (7); the vacuum pump (7) is connected with the top of the feeding tank (3) and is used for realizing the vacuum pumping inside the feeding tank (3); the vacuum feeding machine (4) is connected with the upper part of the feeding tank (3) and is used for conveying solid urea into the feeding tank (3); the bottom of the feeding tank (3) is connected with the top of the preparation tank (1) and is used for conveying solid urea to the preparation tank (1).

10. An SNCR denitration system using urea as a reducing agent according to any one of claims 1 to 4, characterized by further comprising a second water inlet pipe (6) for conveying demineralized water, wherein the second water inlet pipe (6) comprises a water inlet branch one d and a water inlet branch two e; the first water inlet branch d is connected with the preparation tank (1) and used for conveying desalted water into the preparation tank (1); and the water inlet branch circuit two e is connected with the first branch circuit a and is used for conveying desalted water to the first branch circuit a.