Flue gas treatment system

Abstract

According to the technical scheme, the flue gas treatment system comprises a deamination device and a cooling device, a deamination slurry tank is arranged at the bottom of the deamination device and used for containing deamination slurry, and the cooling device is arranged in the deamination slurry tank. The cooling device is used for extracting deamination slurry contained in the deamination slurry tank so as to carry out cooling and deamination on flue gas at a flue gas inlet of the deamination device, the deamination device is used for carrying out deamination on the introduced flue gas through the deamination slurry, a catalyst is not needed in the whole deamination process, the investment cost is relatively low, and long-time stable operation can be realized.

Description

Technical Field

[0001] The utility model relates to the technical field of environmental protection, in particular to a flue gas treatment system. Background Art

[0002] As the NOx emission indicators of the waste incineration industry in various regions are gradually raised to 80mg / m3 or even 50mg / m3, both the traditional SNCR (selective non-catalytic reduction) and the emerging polymer denitrification technology have led to an increase in the excess of reduced ammonia, and ammonia escape is very serious. New standards in various regions have also begun to restrict the emission of ammonia escape.

[0003] Since ammonia escape is still under monitoring in various places for the first time, there is no highly efficient and economical implementation plan. At present, some single projects use SCR (selective catalytic reduction) to remove excess ammonia in flue gas, but the SCR catalyst must be operated at least above 170 degrees, otherwise it is easy to be blocked by ammonium sulfate, so the flue gas needs to be heated, resulting in extremely high operating costs of 30-40 yuan per ton of garbage, and the initial investment in equipment reaches 10 million. In addition, if the operation time is slightly longer, ammonium sulfate will still block the channels of the SCR catalyst, so it cannot operate stably for a long time. Utility Model Content

[0004] In order to solve the above technical problems, the main purpose of the utility model is to provide a flue gas treatment system, aiming to reduce the cost of deammoniation and enable the system to operate for a long time.

[0005] In order to achieve the above object, the utility model proposes a flue gas treatment system, the flue gas treatment system comprising:

[0006] A deamination device, wherein the deamination device is used to deaminize the introduced flue gas by using a deamination slurry, and a deamination slurry pool is provided at the bottom of the deamination device, and the deamination slurry pool is used to hold the deamination slurry; and

[0007] A cooling device is used to extract the deammoniation slurry contained in the deammoniation slurry pool to cool and deammonify the flue gas at the flue gas inlet of the deammoniation device.

[0008] Preferably, the cooling device comprises:

[0009] A first spray plate, disposed at the smoke inlet and provided with a plurality of first nozzles facing the smoke inlet;

[0010] A spray pump, wherein the inlet of the spray pump is connected to the deammoniation slurry pool, and the outlet of the spray pump is connected to the first nozzle.

[0011] Preferably, the deammoniation device comprises a reaction tower, a working chamber is formed in the reaction tower, and the deammoniation slurry pool is arranged at the bottom of the working chamber.

[0012] Preferably, the reaction tower comprises an air uniforming plate, which is arranged in the working chamber and located above the smoke inlet, and the air uniforming plate extends in a horizontal direction and is provided with a plurality of openings.

[0013] Preferably, the reaction tower further comprises at least one spray device, and the spray device comprises:

[0014] a second spray plate, which is arranged in the working chamber and above the air uniforming plate, extends in a horizontal direction and is provided with a plurality of second nozzles facing the air uniforming plate, and

[0015] A circulation pump, wherein the inlet of the circulation pump is connected to the deammoniation slurry pool, and the outlet of the circulation pump is connected to the second nozzle.

[0016] Preferably, the reaction tower further comprises a spray device, and the spray device comprises:

[0017] a second spray plate, which is arranged in the working chamber and above the air uniforming plate, extends in a horizontal direction and is provided with a plurality of second nozzles facing the air uniforming plate, and

[0018] A circulation pump, wherein the inlet of the circulation pump is connected to the deammoniation slurry pool, and the outlet of the circulation pump is connected to the second nozzle.

[0019] Preferably, a defogger with a wire mesh structure is provided above the spray device. The defogger is arranged below the flue gas outlet of the reaction tower and corresponds to the deammoniation slurry pool above and below so that fine liquid in the flue gas can drip into the deammoniation slurry pool after defogger.

[0020] Preferably, the deammoniation device further comprises a cleaning device, and the cleaning device comprises:

[0021] a water tank for holding wash water; and,

[0022] A cleaning water pump, wherein the inlet of the cleaning water pump is communicated with the water tank, and the outlet extends into the reaction tower and faces the defogger to clean the defogger.

[0023] Preferably, the deammoniation device further comprises a dosing device, and the dosing device comprises:

[0024] A dosing box for containing deammoniation agents; and

[0025] A dosing pump, wherein the inlet of the dosing pump is connected to the dosing tank, and the outlet of the dosing pump is connected to the deammoniation slurry pool.

[0026] Preferably, the flue gas treatment system also includes an air intake pipe and a bypass pipe, one end of the air intake pipe is connected to the working chamber, and an induced draft fan and a booster fan are installed in sequence in the pipeline formed by the air intake pipe, and a first valve is provided between the booster fan and the reaction tower; the bypass pipe is provided between the induced draft fan and the booster fan, and a second valve is provided at the inlet of the bypass pipe.

[0027] Preferably, the flue gas treatment system also includes a waste liquid discharge pipe, one end of which is connected to the deammoniation slurry pool, and a third valve is provided in the pipeline formed by the waste liquid discharge pipe to control the discharge of saturated waste liquid generated after the flue gas is deammonified by the deammoniation device. The other end of the waste liquid discharge pipe is connected to a waste liquid recovery device, and the waste liquid recovery device includes a SNCR tank, which is connected to a waste incinerator to denitrify the waste incineration flue gas.

[0028] In the technical solution of the utility model, the new flue gas treatment system includes a deammoniation device and a cooling device. A deammoniation slurry pool is arranged at the bottom of the deammoniation device. The deammoniation slurry pool is used to hold the deammoniation slurry. The cooling device is used to extract the deammoniation slurry held in the deammoniation slurry pool to cool and deammonify the flue gas at the flue gas inlet of the deammoniation device. The deammoniation device is used to deammonify the introduced flue gas through the deammoniation slurry. The entire deammoniation process does not require a catalyst or a special cooling device, has a low investment cost and can operate stably for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0030] Figure 1 This is a structural schematic diagram of the flue gas treatment system provided by the utility model.

[0031] Description of Figure Numbers:

[0032]

[0033]

[0034] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0036] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0037] In addition, the descriptions of "first", "second", etc. in the present utility model are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0038] As the NOx emission indicators of the waste incineration industry in various regions are gradually raised to 80mg / m3 or even 50mg / m3, both the traditional SNCR (selective non-catalytic reduction) and the emerging polymer denitrification technology have led to an increase in the excess of reduced ammonia, and ammonia escape is very serious. New standards in various regions have also begun to restrict the emission of ammonia escape.

[0039] Since ammonia escape is still under monitoring in various places for the first time, there is no highly efficient and economical implementation plan. At present, some single projects use SCR (selective catalytic reduction) to remove excess ammonia in flue gas, but the SCR catalyst must be operated at least above 170 degrees, otherwise it is easy to be blocked by ammonium sulfate, so the flue gas needs to be heated, resulting in extremely high operating costs of 30-40 yuan per ton of garbage, and the initial investment in equipment reaches 10 million. In addition, if the operation time is slightly longer, ammonium sulfate will still block the channels of the SCR catalyst, so it cannot operate stably for a long time.

[0040] In view of this, the utility model proposes a flue gas treatment system, in which the entire deammoniation process does not require a catalyst, the investment cost is low and the system can operate stably for a long time. Figure 1 This is a structural schematic diagram of a flue gas treatment system provided by the utility model.

[0041] Please refer to Figure 1 Since the temperature of the flue gas from garbage incineration is relatively high, generally above 850 degrees, and the deamination system needs to be operated in the temperature range of 80-120 degrees, the flue gas treatment system needs to be provided with a cooling device 2000 and a deamination device 1000. The cooling device 2000 can be a pump or a special suction device to extract the deamination slurry of the flue gas treatment system and then spray it into the flue gas inlet of the deamination device 1000 to cool the flue gas. The cooling device 2000 can be arranged outside the deamination device 1000, or inside the deamination device 1000, or partially outside. In this embodiment, the cooling device 2000 is partially arranged outside and is The deammoniation slurry is cooled. Specifically, a deammoniation slurry pool 2 is provided at the bottom of the deammoniation device 1000. The deammoniation slurry pool 2 is used to hold the deammoniation slurry. The deammoniation slurry contains water and acidic substances. The cooling device 2000 is used to extract the deammoniation slurry in the deammoniation slurry pool 2 to cool the flue gas at the flue gas inlet of the deammoniation device 1000. Since the deammoniation slurry contains water and acidic substances, it can also be preliminarily deammonified during the cooling process. Then, the deammoniation device 1000 further deammonifies the cooled flue gas through the deammoniation slurry. The entire deammoniation process does not require a catalyst or special cooling equipment, has a low investment cost and can operate stably for a long time.

[0042] In order to achieve a better cooling effect, in this embodiment, the cooling device 2000 is provided with a first spray plate 200 and a spray pump 300. The first spray plate 200 is arranged at the flue gas inlet and extends in a direction perpendicular to the flue gas entering, so that the contact area with the flue gas is larger. The first spray plate 200 is also provided with a plurality of first nozzles 200a facing the flue gas inlet. The specific shape of the first nozzle 200a is not limited here, and can be a "V" shape or a "U" shape; the deammoniation slurry pool 2 is provided with a first Water outlet, one end of the spray pump 300 is connected to the first water outlet through a drain pipe, and the other end is connected to the first nozzle 200a through a connecting pipe to pump the deammoniation slurry into the first nozzle 200a. The specific form and installation method of the spray pump 300 are not limited. For example, it can be a centrifugal pump or an axial flow pump. The installation method can be placed in the deammoniation slurry pool 2 or outside the deammoniation slurry pool 2. In the present embodiment, the spray pump 300 is an external acid-resistant and alkali-resistant vertical centrifugal pump, which increases its service life.

[0043] In order to make the gas and liquid fully contact, the deamination process is carried out in the reaction tower 100. Please continue to refer to Figure 1A working chamber 1 is formed inside the reaction tower 100 so that the deammoniation process of the flue gas is carried out in the working chamber 1. Considering that the flue gas contains more acid gases such as HCl, HF, SO2, etc., acid liquid will be formed after the temperature is reduced to the acid dew point. Therefore, the working chamber 1 is sprayed with corrosion-resistant plastic or rubber. The deammoniation slurry pool 2 is arranged at the bottom of the working chamber 1. When the flue gas enters the working chamber 1 of the deammoniation tower and flows from bottom to top, it contacts with water and acidic substances in the deammoniation slurry so that ammonia in the flue gas is absorbed to achieve deammoniation.

[0044] It can be understood that, in the present embodiment, the working chamber 1 of the reaction tower 100 is provided with a smoke inlet and a smoke outlet. The smoke enters the working chamber 1 after being cooled at the smoke inlet. Since the change in space may cause flow field turbulence, a uniform wind plate 3 is also provided above the smoke inlet of the working chamber 1. The uniform wind plate 3 extends in a horizontal direction and at least a portion of its edge abuts against the inner wall of the working chamber 1. The uniform wind plate 3 is also provided with a plurality of evenly distributed through holes, so that the smoke can standardize the flow field when passing through the uniform wind plate 3 from the smoke inlet, so that the smoke can move evenly along the through holes.

[0045] Furthermore, the flue gas flows through the uniform air plate 3 upward through the spray device 4 for further deammoniation. Specifically, the spray device 4 includes a second spray plate 41 and a circulating pump 42. The second spray plate 41 is arranged in the working chamber 1, extending in the horizontal direction and its edge abuts against the inner wall of the working chamber 1 to increase the gas-liquid contact area. In addition, considering that the deammoniation slurry is an acidic or alkaline liquid, the material of the second spray plate 41 should be corrosion-resistant, such as PP material (polypropylene). The second spray plate 41 is also provided with a plurality of second nozzles 41a facing the uniform air plate 3. The specific shape of the second nozzle 41a is not limited here, and can be a "V" type or a "U" type. The deammoniation slurry pool 2 A second water outlet is provided, one end of the circulation pump 42 is connected to the second water outlet through a circulation water pipe, and the other end is connected to the second nozzle 41a through a connecting pipe to pump the deammoniation slurry into the second nozzle 41a. The flue gas flows through the second nozzle 41a and contacts with the deammoniation slurry sprayed from the second nozzle 41a, and ammonia in the flue gas is absorbed to achieve deammoniation. It can be understood that the circulation pump 42 can realize the recycling of the deammoniation slurry. In order to improve the deammoniation efficiency, the spray device 4 is provided with multiple. In this embodiment, the working chamber 1 is provided with 3 identical spray devices 4 to make the slurry evenly distributed in the absorption tower. Specifically, 3 second spray plates 41 are provided, and 3 circulation pumps 42 are also provided corresponding to the second spray plates 41.

[0046] Since the high-temperature flue gas has fine droplets in the jacket after being cooled and sprayed, a demisting device is provided in the working chamber 1 above the spraying device 4. The specific form of the demisting device is not limited here, for example, it can be a corrugated blade demisting device or a wire mesh demisting device 5. In this embodiment, the demisting device is a wire mesh demisting device 5. Specifically, the wire mesh demisting device 5 includes a filter mat and a grille.

[0047] The filter mesh pad extends in the horizontal direction and its shape is adapted to the working chamber 1. The grille is used to support the filter mesh pad to prevent it from shifting. When the smoke after spraying passes through the filter mesh pad of the wire mesh demister 5, the mist droplets hit the filter mesh pad and are adhered or adsorbed. After repeated adsorption of the mist droplets, the extremely small mist droplets agglomerate and coalesce into large droplets. Under the action of gravity, the droplets move downward along the intersection of the wires of the filter mesh pad. The wire mesh demister 5 is arranged opposite to the deammoniation slurry pool 2 in upper and lower directions so that large droplets fall into the deammoniation slurry pool 2.

[0048] Since crystals will form on the surface of the wire mesh demister 5 during operation, the deammonification system is also provided with a cleaning device 400. Specifically, the cleaning device 400 includes a water tank 401 and a cleaning water pump 402. The water tank 401 contains cleaning water and is provided with a water outlet. One end of the cleaning water pump 402 is connected to the water outlet of the water tank 401 through a water pipe, and the other end is connected to the water pipe and extends into the working chamber 1 of the reaction tower 100 toward the filter mesh pad and the grille to clean them. Similarly, the cleaning water pump 402 can be an external centrifugal water pump to save space in the reaction tower 100.

[0049] It can be understood that after the flue gas is defogged, the fine droplets therein become large droplets and fall into the deammoniation slurry pool 2, which will cause the liquid level in the deammoniation slurry pool 2 to rise and the concentration of the deammoniation agent to decrease. Therefore, a liquid level gauge is provided on the inner wall of the deammoniation slurry pool 2 to reasonably add medicine through the dosing device 500 according to the liquid level of the deammoniation slurry. Specifically, the dosing device 500 includes a dosing box 501 and a dosing pump 502. The dosing box 501 contains the deammoniation agent and is provided with a drain port. One end of the dosing pump 502 is connected to the drain port of the dosing box 501 through a connecting pipe, and the other end is connected to the deammoniation slurry pool 2 to pump the deammoniation agent into the deammoniation slurry pool 2. Similarly, the dosing pump 502 can also be an external centrifugal water pump to save space in the reaction tower 100.

[0050] The flue gas treatment system can be used to treat waste incineration flue gas. It can be understood that the flue gas in the waste incinerator is connected to the working chamber 1 through the air inlet pipe 600. Considering that the increase in resistance after adding the deammonification system will change the negative pressure environment in the waste incinerator, an induced draft fan 800 and a booster fan 900 are installed in sequence in the pipeline formed by the air inlet pipe 600 to ensure that the incinerator operates at a slight negative pressure. The specific types of the induced draft fan 800 and the booster fan 900 are not limited here. In one embodiment, the induced draft fan 800 is a centrifugal axial flow fan and / or the booster fan The fan 900 is a centrifugal fan. In order to facilitate the control of the emission of flue gas in the reaction tower 100, a first valve is further provided between the booster fan 900 and the reaction tower 100. Considering that the cleaning of the defogger or other working conditions such as equipment failure will affect the flue gas channel at the rear end and the first valve needs to be closed, a bypass pipe 700 is further provided between the induced draft fan 800 and the booster fan 900 to allow the flue gas to be discharged through the bypass pipe 700. It can be understood that when the deammonification system is operating normally, the second valve is in a closed state.

[0051] After deammoniation, the flue gas exists in the deammoniation slurry in the deammoniation slurry pool 2 in the form of ammonium salt to form waste liquid. After repeated spraying deammoniation, the content of ammonium salt in the waste liquid increases. A pH detector is provided on the inner wall of the deammoniation slurry pool 2 to detect the pH value of the waste liquid to determine whether it has reached saturation. Considering the reuse of saturated waste liquid, the waste liquid generated by the deammonification system is used in the flue gas denitrification system. Specifically, the deammoniation slurry pool 2 is provided with a third water outlet, and the third water outlet is connected to a waste liquid discharge pipe. A third valve is provided in the pipeline formed by the waste liquid discharge pipe. A door is provided to control the discharge of saturated waste liquid generated after flue gas deammoniation by the deammonification device 1000. The other end of the waste liquid discharge pipe is connected to a waste liquid recovery device, which includes an SNCR tank. The saturated waste liquid in the SNCR tank is connected to a waste ammonia water pipe and a soft water pipe, and then connected to form a mixed water pipe and then sprayed into the waste incinerator, so that the diluted saturated waste liquid is used as a reducing agent of the denitrification system to denitrify the incineration flue gas; in another embodiment, after the waste liquid is saturated, it can be discharged into a leachate treatment station through the waste liquid discharge pipe at a regular time for neutralization treatment.

[0052] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A flue gas treatment system, characterized in that: include: A deammoniation device, wherein the deammoniation device is used to deammonify the introduced flue gas by using a deammoniation slurry, and a deammoniation slurry pool is provided at the bottom of the deammoniation device, wherein the deammoniation slurry pool is used to hold the deammoniation slurry; as well as, A cooling device is used to extract the deammoniation slurry contained in the deammoniation slurry pool to cool and deammonify the flue gas at the flue gas inlet of the deammoniation device.

2. The flue gas treatment system according to claim 1, characterized in that: The cooling device comprises: A first spray plate, disposed at the smoke inlet and provided with a plurality of first nozzles facing the smoke inlet; A spray pump, wherein the inlet of the spray pump is connected to the deammoniation slurry pool, and the outlet of the spray pump is connected to the first nozzle.

3. The flue gas treatment system according to claim 1, characterized in that: The deammoniation device comprises a reaction tower, a working chamber is formed in the reaction tower, and the deammoniation slurry pool is arranged at the bottom of the working chamber.

4. The flue gas treatment system according to claim 3, characterized in that: The reaction tower comprises an air uniforming plate, which is arranged in the working chamber and located above the smoke inlet. The air uniforming plate extends in a horizontal direction and is provided with a plurality of openings.

5. The flue gas treatment system according to claim 4, characterized in that: The reaction tower further comprises at least one spray device, wherein the spray device comprises: a second spray plate, which is arranged in the working chamber and above the air uniforming plate, extends in a horizontal direction and is provided with a plurality of second nozzles facing the air uniforming plate, and A circulation pump, wherein the inlet of the circulation pump is connected to the deammoniation slurry pool, and the outlet of the circulation pump is connected to the second nozzle.

6. The flue gas treatment system according to claim 5, characterized in that: A defogger with a wire mesh structure is also provided above the spray device of the working chamber. The defogger is arranged below the flue gas outlet of the reaction tower and corresponds to the deammoniation slurry pool up and down so that fine liquid in the flue gas can drip into the deammoniation slurry pool after defogger.

7. The flue gas treatment system according to claim 6, characterized in that: The deammoniation device further comprises a cleaning device, which comprises: a water tank for holding wash water; and, A cleaning water pump, wherein the inlet of the cleaning water pump is communicated with the water tank, and the outlet extends into the reaction tower and faces the defogger to clean the defogger.

8. The flue gas treatment system according to claim 1, characterized in that: The deammoniation device further comprises a dosing device, and the dosing device comprises: A dosing box for containing deammoniation agents; and A dosing pump, wherein the inlet of the dosing pump is connected to the dosing tank, and the outlet of the dosing pump is connected to the deammoniation slurry pool.

9. The flue gas treatment system according to claim 3, characterized in that: It also includes an air intake pipe and a bypass pipe, one end of the air intake pipe is connected to the working chamber, an induced draft fan and a booster fan are installed in sequence in the pipeline formed by the air intake pipe, a first valve is provided between the booster fan and the reaction tower; the bypass pipe is provided between the induced draft fan and the booster fan, and a second valve is provided at the inlet of the bypass pipe.

10. The flue gas treatment system according to claim 1, characterized in that: It also includes a waste liquid discharge pipe, one end of which is connected to the deammoniation slurry pool. A third valve is provided in the pipeline formed by the waste liquid discharge pipe to control the discharge of saturated waste liquid generated after the deammoniation device deammonifies the flue gas. The other end of the waste liquid discharge pipe is connected to a waste liquid recovery device, which includes an SNCR tank. The SNCR tank is connected to a waste incinerator to denitrify the waste incineration flue gas.

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