Medium-temperature low-dust denitration device suitable for cement clinker production line flue gas

Abstract

The utility model discloses a medium-temperature low-dust denitration device suitable for cement clinker production line flue gas, which comprises a dust removal denitration tower, and the dust removal denitration tower is composed of a gas inlet flue, a dust hopper, a filter chamber, a gas purification chamber, a reducing gradually-shrinking connecting flue and a denitration reactor which are communicated in sequence; a dust removal cloth bag is arranged in the filter chamber, a filter bag ash removal mechanism is arranged in the gas purification chamber, a rectification grid is arranged in the reducing and gradually-shrinking connecting flue, and a high-temperature catalyst layer is arranged in the denitration reactor; according to the dedusting and denitration tower provided by the invention, the dedusting and denitration tower is characterized in that a connecting flue of a deduster and a denitration reactor adopts a reducing and gradually-shrinking connecting flue structure, so that on one hand, a flue gas flow field entering a first-layer catalyst of the denitration reactor is obviously uniform, and the denitration effect is obviously improved; on the other hand, the construction cost is also obviously reduced; the device is simple in structure, convenient to operate and worthy of popularization.

Description

Technical Field

[0001] The utility model relates to the technical field of denitration equipment, and in particular to a medium-temperature low-dust denitration device suitable for flue gas of a cement clinker production line. Background Art

[0002] When the existing cement kiln tail gas denitrification adopts the high temperature and low dust route, a dust removal and denitrification tower integrating the dust removal device and the denitrification device is often set. Currently, the following three structural forms are mainly used in practice:

[0003] 1. A denitration reactor with the same cross section is directly set on the top of the dust collector. Although this structural form greatly reduces the height of the denitration reactor, its cross section connecting the flue is also the largest, so it may not necessarily save construction costs. At the same time, in terms of the denitration effect, once the dust collector starts to spray bags, since only one of the dust bag areas can be sprayed in turn during actual operation, this causes uneven flue gas flow fields in the sprayed and unsprayed areas, thus affecting the denitration effect.

[0004] Second, a tapered flue is first set on the top of the dust collector (its lower cross-section is still basically equal to the cross-section of the top of the dust collector) and then connected to the denitrification reactor. If the tapered flue is reasonably designed, the flue gas flow field is very uniform. However, in terms of volume alone, the amount of material used in the tapered flue is already considerable. In addition, a large number of reinforcing ribs, internal support rods and other reinforcing structural parts must be set on the tapered flue, or the thickness of the wall panels must be directly increased to cope with the negative pressure of the flue gas and the load of the upper denitrification reactor. These ultimately lead to the construction cost of this structure being the largest among several structures.

[0005] In short, the existing cement kiln tail gas denitrification scheme still needs to be improved. Utility Model Content

[0006] The purpose of the utility model is to provide a medium-temperature low-dust denitrification device suitable for flue gas in a cement clinker production line to solve the problems raised in the above-mentioned background technology.

[0007] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a medium-temperature low-dust denitrification device suitable for flue gas of a cement clinker production line, wherein the device comprises a dust removal and denitrification tower, wherein the dust removal and denitrification tower is composed of an air intake flue, an ash hopper, a filter chamber, a clean air chamber, a flue with different diameters and a denitrification reactor connected in sequence;

[0008] A dust removal bag is arranged in the filter chamber, a filter bag cleaning mechanism is arranged in the clean air chamber, a rectifying grid is arranged in the flue with different diameters and tapers, and a high-temperature catalyst layer is arranged in the denitration reactor; the air intake flue is located above the ash hopper, the filter chamber is located above the ash hopper, the clean air chamber is located above the filter chamber, the flue with different diameters and tapers is located above the clean air chamber, and the denitration reactor is located above the flue with different diameters and tapers.

[0009] Preferably, the lower cross-section of the reducing flue is smaller than the cross-section of the clean air chamber; the reducing flue is a reducing flue, and the four side wall panels are inclined at a certain angle to the horizontal plane, and the dust removal and denitrification connecting flue 8 is located above the clean air chamber 6.

[0010] Preferably, the air inlet flue is provided with a reducing agent dual-fluid fixed spray gun for spraying ammonia water.

[0011] Preferably, a plurality of ash hoppers are provided.

[0012] Beneficial effect: Compared with the prior art, the beneficial effect of the utility model is that the structural form of connecting the flue with different diameters and gradually reducing the diameters avoids the uneven flue gas flow field caused by the difference between the states of the bags in each area of ​​the dust collector that have been sprayed and those that have not been sprayed. On the other hand, a large-section denitrification reactor will cause the flue gas flow rate in the denitrification reactor to be too low, which can easily cause the remaining ash in the flue gas to be blocked in the catalyst pores, and even a strong soot blowing system has to be set up to ensure the normal operation of the system. The cross-section of the denitrification reactor of the utility model is significantly smaller, so it greatly avoids the situation where the catalyst is blocked due to too low a flue gas flow rate, and even the soot blowing system is not required; the structural form of connecting the flue with different diameters and gradually reducing the diameters greatly reduces the construction cost, while still ensuring a uniform flue gas flow field, thereby ensuring an excellent denitrification effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The utility model provides a schematic diagram of the overall structure of a medium-temperature low-dust denitrification device suitable for flue gas in a cement clinker production line.

[0014] Figure 2 This is a schematic structural diagram of an AA cross-sectional view of a medium-temperature low-dust denitrification device suitable for flue gas in a cement clinker production line proposed by the utility model.

[0015] In the attached figure: 1-reducing agent dual-fluid fixed spray gun, 2-air inlet flue, 3-ash hopper, 4-filter chamber, 5-dust removal bag, 6-clean air chamber, 7-filter bag cleaning mechanism, 8-different diameter tapered connecting flue, 9-denitrification reactor, 10-high temperature catalyst layer, 11-rectifier grid. DETAILED DESCRIPTION

[0016] In order to more clearly understand the above-mentioned purpose, features and advantages of the utility model, the utility model is further described below in conjunction with the accompanying drawings and embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0017] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways than those described herein. Therefore, the present invention is not limited to the specific embodiments of the following disclosure.

[0018] Example

[0019] Please refer to the drawings of the specification. In the embodiment of the utility model, a medium-temperature low-dust denitrification device suitable for the flue gas of a cement clinker production line includes a dust removal and denitrification tower, which is composed of an air intake duct, an ash hopper, a filter chamber, a clean air chamber, a flue with a different diameter and a denitrification reactor connected in sequence; a dust removal bag 5 is arranged in the filter chamber 4, a filter bag cleaning mechanism 7 is arranged in the clean air chamber 6, a rectifying grid 11 is arranged in the flue with a different diameter and a converging connection duct 8, and a high-temperature catalyst layer 10 is arranged in the denitrification reactor 9; the air intake duct 2 is located above the ash hopper 3, the filter chamber 4 is located above the ash hopper 3, the clean air chamber 6 is located above the filter chamber 4, the flue with a different diameter and a converging connection duct 8 is located above the clean air chamber 4, and the denitrification reactor 9 is provided with a high-temperature catalyst layer 10; the air intake duct 2 is located above the ash hopper 3, the filter chamber 4 is located above the ash hopper 3, the clean air chamber 6 is located above the filter chamber 4, the flue with a different diameter and a converging connection duct 8 is located above the clean air chamber 4, and the denitrification reactor 9 is provided with a high-temperature catalyst layer 10. The denitrification reactor is located above the said flue duct 8 with different diameters and different convergences, and the lower section of the said flue duct 8 with different diameters and different convergences is smaller than the section of the clean air chamber 6; the said flue duct 8 with different diameters and different convergences is a tapered flue, and the four side wall plates are inclined at a certain angle to the horizontal plane, so the change of the flue gas flow direction from the horizontal flow direction to the vertical flow direction is a slow turn instead of a sharp right-angle turn, and the flue gas is converging instead of diverging; a rectifying grid 11 is arranged on its upper part to make the flue gas flow direction uniform again; the characteristics of the said flue duct 8 with different diameters and different convergences can make the flue gas flow field entering the first layer of catalyst of the denitrification reactor become significantly uniform, so the denitrification effect is significantly improved, and the said air inlet flue is provided with a reducing agent dual-fluid fixed spray gun 1 for spraying ammonia water, and the said ash hopper 3 is provided with a plurality of them.

[0020] Usage process:

[0021] When in use, the reducing agent is sprayed into the air inlet flue 2 of the above-mentioned dust removal and denitration tower through the ammonia water injection device 1 to mix with the high-temperature flue gas. After that, the ammonia-smoke mixed gas first enters the ash hopper 3 at the bottom of the dust collector, and then enters the filter chamber 4 at the top from the ash hopper 3. During this period, the ammonia-smoke mixed gas turns and flows and is fully mixed. However, since the dust bags 5 in each area of ​​the filter chamber 4 are different in terms of spraying and not yet spraying, the flue gas flow rate in each dust bag 5 area is also different. The flue gas continues to flow upward into the clean air chamber 6, and the filter bag cleaning mechanism 7 in the clean air chamber 6 sprays each dust bag 5 area in turn, and the dust falls off the surface of the dust bag 5 and falls into the ash hopper 3. Because the clean air chamber 6 also bears the role of extracting the dust bag 5 for maintenance, it must have a considerable volume, which provides a space for uniform mixing of the flue gas in each area with uneven flow rate. At the same time, since the lower cross-section of the flue 8 with different diameters above the clean air chamber 6 is about half smaller than the cross-section of the clean air chamber (the specific cross-section is determined by the design of the denitration reactor), the flue gas must first be concentrated to the lower cross-section of the flue 8 with different diameters before continuing to enter the flue duct with different diameters upward. This flue gas convergence makes the flue gas mixed more evenly again; but it is also due to this flue gas convergence that the flue gas flow direction from the clean air chamber to the denitration reactor 9 needs to undergo a change from a horizontal flow direction to a vertical flow direction. If this flow direction change is abrupt, the flow field will become uneven. After that, the flue gas is slowly turned and converged by the structural form of the flue duct with different diameters 8, and the rectifying grid 11 set in the flue duct with different diameters 8 again adjusts the flue gas flow direction in a uniform manner; thereafter, the flue gas flows through the high-temperature catalyst layer 10 set in the above-mentioned denitration reactor 9 for denitration, and when it flows to the outlet of the denitration reactor 9, the required dust removal and denitration effects have been achieved.

[0022] Compared with the structure of directly setting a denitrification reactor of the same cross section on the top of the dust collector, the utility model avoids the uneven flue gas flow field caused by the difference between the states of the bags in each area of ​​the dust collector that have been sprayed and those that have not been sprayed by using the structure of the flue gas with different diameters and gradually contracting. On the other hand, a denitrification reactor with a large cross section will cause the flue gas flow rate in the denitrification reactor to be too low, which can easily cause the remaining ash in the flue gas to be blocked in the catalyst pores, and even a strong soot blowing system has to be set up to ensure the normal operation of the system. The cross-section of the denitrification reactor of the utility model is significantly smaller, so it greatly avoids the situation where the catalyst is blocked due to too low a flue gas flow rate, and even a soot blowing system is not required.

[0023] Compared with the structural form of first setting a tapered flue connecting the top of the dust collector (whose lower cross-section is still basically equal to the cross-section of the top of the dust collector) and then connecting the denitrification reactor, the utility model greatly reduces the construction cost by using the structural form of the flue connecting with different diameters, while still ensuring a uniform flue gas flow field, thereby ensuring an excellent denitrification effect.

[0024] In the above process, the structural form of connecting the flue with different diameters and gradually reducing them avoids the uneven flue gas flow field caused by the difference between the states of the bags in each area of ​​the dust collector that have been sprayed and those that have not been sprayed. On the other hand, a large-cross-section denitrification reactor will cause the flue gas flow rate in the denitrification reactor to be too low, which can easily cause the remaining ash in the flue gas to be blocked in the catalyst pores, and even a strong soot blowing system has to be set up to ensure the normal operation of the system. The cross-section of the denitrification reactor of the utility model is significantly smaller, so it greatly avoids the situation where the catalyst is blocked due to too low a flue gas flow rate, and even the soot blowing system is not required; the structural form of connecting the flue with different diameters and gradually reducing them greatly reduces the construction cost, while still ensuring a uniform flue gas flow field, thereby ensuring an excellent denitrification effect; the present application has a simple structure, strong practicality, and simple operation, which is worth promoting.

[0025] The above are only preferred implementations of the utility model. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the concept of the utility model. These should also be regarded as the protection scope of the utility model. These will not affect the effect of the implementation of the utility model and the practicality of the patent.

Claims

1. A medium-temperature low-dust denitrification device suitable for flue gas from a cement clinker production line, characterized in that: It comprises a dust removal and denitration tower, which is composed of an air intake flue, an ash hopper, a filter chamber, a clean air chamber, a flue with different diameters and a denitration reactor that are connected in sequence; The filter chamber is provided with a dust removal bag, the clean air chamber is provided with a filter bag cleaning mechanism, the flue gas duct with different diameters is provided with a rectifying grid, and the denitration reactor is provided with a high-temperature catalyst layer; the air intake flue is located above the ash hopper, the filter chamber is located above the ash hopper, the clean air chamber is located above the filter chamber, the flue gas duct with different diameters is located above the clean air chamber, and the denitration reactor is located above the flue gas duct with different diameters; The lower section of the different-diameter tapered connecting flue is smaller than the section of the clean air chamber; the different-diameter tapered connecting flue is a tapered flue, and the four side wall plates are all inclined at a certain angle to the horizontal plane.

2. A medium-temperature low-dust denitrification device suitable for flue gas in a cement clinker production line according to claim 1, characterized in that: The air inlet flue is provided with a reducing agent dual-fluid fixed spray gun for spraying ammonia water.

3. A medium-temperature low-dust denitrification device suitable for flue gas in a cement clinker production line according to claim 1, characterized in that: The ash hopper is provided in plurality.

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