A slag-condensing pipe, a self-cleaning slag-condensing air distribution plate and a flue gas treatment system

Abstract

The present invention provides a slag coagulation pipe, a self-cleaning slag coagulation air distribution plate and a flue gas treatment system. The slag coagulation pipe is used in the self-cleaning slag coagulation air distribution plate. A plurality of slag coagulation protrusions are arranged on the outer side wall of the slag coagulation pipe, and the slag coagulation protrusions are used for accelerating slag coagulation. A plurality of air distribution openings are formed on the outer side wall of the slag coagulation pipe on the side opposite to the plurality of slag coagulation protrusions. The self-cleaning slag coagulation air distribution plate includes a box body, a plurality of the slag coagulation pipes, and a plurality of slag removal devices. An inlet and an outlet are respectively formed at both ends of the box body. The plurality of slag coagulation pipes are fixed inside the box body in a manner perpendicular to the axis of the box body, and the axis is the axis passing through the inlet of the box body and the outlet of the box body. The inlets and outlets of the slag coagulation pipes are located outside the box body, and the slag coagulation protrusions of the slag coagulation pipes face the inlet of the box body, and the air distribution openings face the outlet of the box body. The plurality of slag removal devices are devices for removing the slag coagulated on the surface of the slag coagulation pipes.

Description

Technical Field

[0001] The present invention relates to a slag coagulation pipe, a self-cleaning slag coagulation air distribution plate and a flue gas treatment system, belonging to the technical field of flue gas treatment in the iron and steel industry. Background Art

[0002] The flue gas treatment system in the iron and steel industry usually adds an SCR system after wet desulfurization. The system process is generally: wet desulfurization → demister → wet electrostatic precipitator → first-stage heating → cold side of gas-gas heater (GGH) → second-stage heating → denitration reactor → hot side of GGH → booster fan → chimney.

[0003] The composition of sintering flue gas is complex and the working conditions fluctuate greatly. In this system, after the flue gas comes out of the wet electrostatic precipitator and until it enters the cold side of the GGH, the flue gas contains a large amount of liquid and gel-like particles, and it is very easy to form relatively hard caked ash slag on the cold side of the GGH, and adhere to the cold side of the GGH, resulting in the blockage of the GGH, which causes the system pressure to rise, increases the cost per ton of ore, and seriously causes the system to shut down.

[0004] Through the projects that have been put into operation, it can be found that this phenomenon is very common. Once this situation occurs, the GGH will be quickly blocked. It is very difficult to achieve on-line cleaning only by the self-cleaning system of the GGH itself, and it is necessary to shut down the machine to clean the blockage or replace the GGH module.

[0005] For the problem of a large amount of slagging at the cold-side inlet of the GGH in existing projects, the vast majority of projects adopt adding purging equipment or flushing equipment at the GGH inlet, and use compressed air, nitrogen, steam, etc. for purging, or use high-pressure water for flushing. This measure only adds purging or flushing equipment at the GGH inlet, and there is basically no way to remove the ash slag caked on the GGH. The resistance and heat transfer efficiency of the GGH have not been restored, and the actual operation effect is extremely unsatisfactory.

[0006] In addition, some existing projects also adopt adding slag-blocking equipment similar to a "curtain" (iron chain, wire mesh, etc.) at the GGH inlet, and the "curtain" can be regularly pulled out of the flue through a "rolling curtain" device, washed and then pulled back into the flue through the "rolling curtain" device. However, this facility is simple and crude, and does not play a role in blocking and intercepting ash slag, and the problem of GGH blockage still cannot be solved.

[0007] Therefore, providing a new, simple device that can greatly reduce the slagging situation at the cold-side inlet of the GGH has become an urgent technical problem in this field. Summary of the Invention

[0008] In order to solve the above-mentioned disadvantages and deficiencies, the purpose of the present invention is to provide a slag coagulation pipe, a self-cleaning slag coagulation air distribution plate and a flue gas treatment system.

[0009] To achieve the above object, on the one hand, the present invention provides a slag coagulation tube for a self-cleaning slag coagulation air distribution plate, wherein a plurality of slag coagulation protrusions are provided on the outer side wall of the slag coagulation tube, and the slag coagulation protrusions are used to accelerate slag coagulation;

[0010] A plurality of air distribution openings are formed on the outer side wall of the slag coagulation tube on the side opposite to the plurality of slag coagulation protrusions.

[0011] In the above-mentioned slag coagulation tube, preferably, the slag coagulation protrusions are arranged in a longitudinal row along the circumferential direction of the slag coagulation tube on the outer side wall of the slag coagulation tube.

[0012] In the above-mentioned slag coagulation tube, preferably, a plurality of the air distribution openings are connected with short tubes. Among them, the short tubes connected to the air distribution openings can play a role in reverse flow, and thus can overcome the eddy current on the leeward side of the slag coagulation tube.

[0013] In the above-mentioned slag coagulation tube, preferably, the slag coagulation protrusions are columnar or spherical protrusions.

[0014] In the above-mentioned slag coagulation tube, preferably, the material of the slag coagulation tube is stainless steel.

[0015] In the above-mentioned slag coagulation tube, the slag coagulation protrusions can increase the surface area of the slag coagulation tube and increase the surface roughness of the slag coagulation tube, which is beneficial to capturing liquid and gel-like particles in the flue gas and improving the slag coagulation effect; a plurality of air distribution openings are formed on the outer side wall of the slag coagulation tube on the side opposite to the plurality of slag coagulation protrusions (corresponding to the leeward side during application), which can reduce the flue gas eddy current on the leeward side of the slag coagulation tube, keep the flue gas in a better flow field distribution, and reduce the slag coagulation on the leeward side of the slag coagulation tube. That is, if the air distribution openings are not provided on the leeward side, eddy currents will be formed on the leeward side, and thus slag will accumulate on the leeward side of the slag coagulation tube.

[0016] In the above-mentioned slag coagulation tube, the present invention does not make specific requirements on the specific manner of arranging the slag coagulation protrusions on the outer side wall of the slag coagulation tube, and those skilled in the art can reasonably select the setting method according to the on-site operation needs; for example, in the specific embodiment of the present invention, the slag coagulation protrusions can be fixed on the outer side wall of the slag coagulation tube by welding; in addition, the present invention does not make specific requirements on the specific layout methods of the slag coagulation protrusions and the air distribution openings, such as whether they are evenly distributed, the layout spacing and quantity, etc. Those skilled in the art can also reasonably set them according to the on-site operation needs. A plurality of slag coagulation protrusions are provided on the outer side wall of the slag coagulation tube provided by the present invention, which is more conducive to the condensation of ash slag than a smooth tube and is easier to clean the condensed ash slag than a finned tube.

[0017] On the other hand, the present invention also provides a self-cleaning slag coagulation air distribution plate, wherein the self-cleaning slag coagulation air distribution plate includes a box body, a plurality of the above-mentioned slag coagulation tubes, and a plurality of slag removal devices;

[0018] An inlet and an outlet are respectively provided at both ends of the box body; a plurality of slag-condensing pipes are fixed inside the box body in a manner perpendicular to the axis of the box body, and the axis is the axis passing through the inlet of the box body and the outlet of the box body; the inlets and outlets of the slag-condensing pipes are located outside the box body, and the slag-condensing protrusions of the slag-condensing pipes face the inlet of the box body, and the air distribution openings face the outlet of the box body;

[0019] The plurality of slag-removing devices are devices for removing the slag on the surface of the slag-condensing pipes.

[0020] In the self-cleaning slag-condensing air distribution plate described above, the present invention does not make specific requirements on the installation position and quantity of the slag-removing devices, etc. Those skilled in the art can reasonably select its installation position and quantity according to the needs of on-site operation, as long as it can ensure that the slag-condensing pipes can be regularly flushed, the slag on the surface of the slag-condensing pipes can be removed cleanly, and the slag-condensing pipes can maintain a good slag-condensing working condition and have a good slag-condensing effect;

[0021] Preferably, the slag-removing device is movably arranged on the box body, and the slag-removing device faces the slag-condensing protrusion of the slag-condensing pipe.

[0022] In the self-cleaning slag-condensing air distribution plate described above, preferably, the slag-removing device includes a high-pressure water gun. Among them, the high-pressure water gun used in the present invention can be a conventional high-pressure water gun used in the art; the flushing time and frequency of the high-pressure water gun can also be controlled by a program to realize the automatic operation of the high-pressure water gun, and further realize the self-cleaning function.

[0023] The present invention does not make specific requirements on the layout spacing, pipe length, pipe diameter and the quantity of the slag-condensing pipes used in the self-cleaning slag-condensing air distribution plate. Those skilled in the art can reasonably set the above parameters according to the on-site operation conditions, as long as the purpose of the present invention can be achieved.

[0024] In the self-cleaning slag-condensing air distribution plate described above, the present invention does not make specific requirements on the fixing method of the slag-condensing pipes inside the box body. Those skilled in the art can select a reasonable method to fix the slag-condensing pipes inside the box body according to the on-site situation; for example, in the specific embodiment of the present invention, the slag-condensing pipes can be welded inside the box body.

[0025] The self-cleaning slag-condensing air distribution plate provided by the present invention is simple, reliable, easy to use, and can realize self-cleaning.

[0026] On the other hand, the present invention also provides a flue gas treatment system, including a section of heating furnace and the cold side of the GGH connected by a pipeline; wherein, the flue gas treatment system further includes the self-cleaning slag-condensing air distribution plate described above, the self-cleaning slag-condensing air distribution plate is arranged in the pipeline between the section of heating furnace and the cold side of the GGH, and the axis passing through the inlet of the box body and the outlet of the box body of the self-cleaning slag-condensing air distribution plate is parallel to the flue gas flow direction;

[0027] The inlets and outlets of the slag-removing tubes of the self-cleaning slag-removing air distribution plate are respectively aggregated and connected to the high-temperature medium main pipe.

[0028] In the above-mentioned flue gas treatment system, preferably, the flue gas treatment system further includes a wet desulfurization device, a demister, a wet electrostatic precipitator, a second-stage heating furnace, a denitration reactor, a GGH hot side, a booster fan, and a chimney. The wet desulfurization device, the demister, the wet electrostatic precipitator, the first-stage heating furnace, the GGH cold side, the second-stage heating furnace, the denitration reactor, the GGH hot side, the booster fan, and the chimney are connected in sequence through pipelines.

[0029] In the above-mentioned flue gas treatment system, the wet desulfurization device, the demister, the wet electrostatic precipitator, the first-stage heating furnace, the GGH cold side, the second-stage heating furnace, the denitration reactor, the GGH hot side, the booster fan, and the chimney are all conventional equipment used in the art.

[0030] In the above-mentioned flue gas treatment system, a valve is further provided on the high-temperature medium main pipe. The flow rate of the high-temperature medium passing through the slag-removing tube can be controlled through the valve, so as to control the temperature of the slag-removing tube. Through this control, the most economical operating condition of the slag-removing efficiency and the consumption of the high-temperature medium can be achieved.

[0031] In the above-mentioned flue gas treatment system, the axes of the inlet and the outlet of the box body of the self-cleaning slag-removing air distribution plate being parallel to the flue gas flow direction can make the slag-removing protrusions of the slag-removing tubes located on the windward (flue gas) side to better remove slag; the air distribution openings of the slag-removing tubes are located on the leeward (flue gas) side, so that the high-temperature medium flows out through the air distribution openings, uniformizes the flow field, reduces the eddy current phenomenon on the leeward side, and makes the slag-removing effect more stable.

[0032] In the above-mentioned flue gas treatment system, the present invention does not make specific requirements on the fixing method of the self-cleaning slag-removing air distribution plate in the pipeline between the first-stage heating furnace and the GGH cold side. Those skilled in the art can select a suitable fixing method to fix the self-cleaning slag-removing air distribution plate in the pipeline between the first-stage heating furnace and the GGH cold side according to the on-site operation needs.

[0033] When the flue gas treatment system provided by the present invention is in operation, the inlets and outlets of the slag-removing tubes of the self-cleaning slag-removing air distribution plate are respectively aggregated and connected to the main pipe of high-temperature medium (steam, hot air, hot flue gas, etc.). The high-temperature medium continuously flows through the slag-removing tubes, keeping the slag-removing tubes in a relatively high-temperature state all the time, and the heat source flowing through the slag-removing tubes can be recycled; when the flue gas flows through the slag-removing tubes, the liquid and gel-like particles in the flue gas will quickly dry and adhere to the slag-removing protrusions (acting as condensation nuclei) on the windward side of the slag-removing tubes to achieve rapid slag removal. At the same time, part of the high-temperature medium flows out through the air distribution openings arranged on the leeward side of the slag-removing tubes to ensure that after the flue gas flows through the slag-removing tubes, the generation of eddy currents on the leeward side of the slag-removing tubes is reduced, and the flue gas maintains a good flow field pattern and evenly passes through the self-cleaning slag-removing air distribution plate, increasing the contact opportunities between the liquid and gel-like particles and the slag-removing tubes.

[0034] By arranging the above-mentioned self-cleaning slag-removing air distribution plate in the pipeline (flue) between the first-stage heating furnace and the cold side of the GGH, the present invention can block the liquid and gel-like particles carried in the flue gas, preliminarily remove slag from the flue gas entering the GGH, and make the liquid and gel-like particles condense on the self-cleaning slag-removing air distribution plate, so as to reduce the ash hanging and slagging conditions existing at the inlet of the cold side of the GGH. Moreover, the flue gas after the first-stage heating furnace can be made more uniform, which is beneficial to the reliable, long-term and stable operation of the sintering machine flue gas system.

[0035] Compared with the maintenance and replacement of the heat exchange elements of the GGH, the structure of the slag-removing tubes used in the present invention is simple, convenient to manufacture, low in cost, simple to replace, and small in the amount of maintenance work; and using this kind of slag-removing tubes can achieve better slag-removing effect, and it is also easier to remove the agglomerated and ash residues condensed on the surface of the slag-removing tubes.

[0036] In addition, the self-cleaning slag-removing air distribution plate provided by the present invention can achieve self-cleaning, reducing a large amount of maintenance costs and labor costs, and the operating cost is lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0038] Figure 1 It is a schematic structural diagram of the slag-removing tube provided in Embodiment 1 of the present invention.

[0039] Figure 2 It is a schematic structural diagram (front view) of the self-cleaning slag-removing air distribution plate provided in Embodiment 2 of the present invention.

[0040] Figure 3Structural schematic diagram of the self-cleaning slag-condensing air-distributing plate provided in Embodiment 2 of the present invention( Figure 2 side view).

[0041] Main reference numeral description:

[0042] 1. Slag-condensing pipe;

[0043] 2. Slag-condensing protrusion;

[0044] 3. Short pipe;

[0045] 4. Box body;

[0046] 5. High-pressure water gun;

[0047] 6. First high-temperature medium main pipe;

[0048] 7. Second high-temperature medium main pipe. Specific implementation manners

[0049] In order to have a clearer understanding of the technical features, objectives, and beneficial effects of the present invention, the technical solutions of the present invention will be described in detail below in conjunction with the following specific embodiments, but it should not be construed as a limitation on the implementable scope of the present invention.

[0050] Embodiment 1

[0051] This embodiment provides a slag-condensing pipe. The structural schematic diagram of the slag-condensing pipe 1 is as shown in Figure 1 As can be seen from Figure 1 several slag-condensing protrusions 2 are provided on the outer side wall of the slag-condensing pipe, and the slag-condensing protrusions 2 are used to accelerate slag condensation;

[0052] several air-distributing openings are formed on the outer side wall of the slag-condensing pipe 1 on the side opposite to the several slag-condensing protrusions 2, and the air-distributing openings are connected with short pipes 3;

[0053] In this embodiment, the slag-condensing protrusions 2 are arranged on the outer side wall of the slag-condensing pipe 1 in a longitudinal column form along the circumferential direction of the slag-condensing pipe 1;

[0054] In this embodiment, the slag-condensing protrusions 2 are columnar protrusions;

[0055] In this embodiment, the material of the slag-condensing pipe 1 is stainless steel.

[0056] Embodiment 2

[0057] This embodiment provides a self-cleaning slag-condensing air-distributing plate. The structural schematic diagram of the self-cleaning slag-condensing air-distributing plate is as shown in Figures 2 - 3 As can be seen from Figures 2 - 3As can be seen, the self-cleaning slag-condensing air distributor includes a box body 4, a number of slag-condensing pipes 1 provided in Embodiment 1, and a number of high-pressure water guns 5 (in this embodiment, each slag-condensing pipe is correspondingly provided with a high-pressure water gun).

[0058] An inlet and an outlet are respectively formed at both ends of the box body 4; a number of the slag-condensing pipes 1 are fixed inside the box body 4 in a manner perpendicular to the axis of the box body 4, and the axis is the axis passing through the inlet of the box body 4 and the outlet of the box body 4; the inlets and outlets of the slag-condensing pipes 1 are located outside the box body 4, and the slag-condensing protrusions 2 of the slag-condensing pipes 1 face the inlet of the box body 4, and the air distribution openings face the outlet of the box body 4.

[0059] The high-pressure water gun 5 is used to remove the slag on the surface of the slag-condensing pipe 1, and it is movably arranged on the box body 4, and the high-pressure water gun 5 faces the slag-condensing protrusion 2 of the slag-condensing pipe 1.

[0060] Embodiment 3

[0061] This embodiment provides a flue gas treatment system, which includes a wet desulfurization device, a demister, a wet electrostatic precipitator, a first-stage heating furnace, the cold side of a GGH, a second-stage heating furnace, a denitration reactor, the hot side of a GGH, a booster fan, and a chimney that are sequentially connected through pipelines.

[0062] Among them, the flue gas treatment system further includes the self-cleaning slag-condensing air distributor provided in Embodiment 2. This self-cleaning slag-condensing air distributor is arranged in the pipeline between the first-stage heating furnace and the cold side of the GGH, and the axis passing through the inlet and the outlet of the box body of this self-cleaning slag-condensing air distributor is parallel to the flue gas flow direction.

[0063] The inlets and outlets of the slag-condensing pipes of the self-cleaning slag-condensing air distributor are respectively aggregated and connected to a first high-temperature medium main pipe 6 and a second high-temperature medium main pipe 7.

[0064] When the flue gas treatment system provided in Embodiment 3 of the present invention works, the inlets and outlets of the slag-condensing pipes of the self-cleaning slag-condensing air distributor are respectively aggregated and connected to a high-temperature medium (steam, hot air, hot flue gas are all acceptable) main pipe. The high-temperature medium continuously flows through the slag-condensing pipes, so that the slag-condensing pipes are always in a relatively high temperature state, and the heat source flowing through the slag-condensing pipes can be recycled and reused; when the flue gas flows through the slag-condensing pipes, the liquid and gel-like particles in the flue gas will quickly dry and solidify on the slag-condensing protrusions (acting as condensation nuclei) on the windward side of the slag-condensing pipes to achieve rapid slag condensation. At the same time, part of the high-temperature medium flows out through the air distribution openings formed on the leeward side of the slag-condensing pipes, so as to ensure that after the flue gas flows through the slag-condensing pipes, the generation of eddy currents on the leeward side of the slag-condensing pipes is reduced, and the flue gas maintains a good flow field pattern and uniformly passes through this self-cleaning slag-condensing air distributor, increasing the chance of contact between the liquid and gel-like particles and the slag-condensing pipes.

[0065] By arranging the self-cleaning slag-condensing air distribution disc as described above in the pipeline (flue duct) between the first-stage heating furnace and the cold side of the GGH, liquid and gel-like particles carried in the flue gas can be blocked, and the flue gas entering the GGH can be preliminarily slag-condensed, so that the liquid and gel-like particles are condensed on the self-cleaning slag-condensing air distribution disc, thereby reducing the ash hanging and slagging at the cold-side inlet of the GGH. Moreover, the flue gas after the first-stage heating furnace can be made more uniform, which is beneficial to the reliable, long-term and stable operation of the sintering machine flue gas system;

[0066] Compared with the maintenance and replacement of GGH heat exchange elements, the structure of the slag-condensing pipe used in the present invention is simple, convenient to manufacture, low in cost, simple to replace, and small in maintenance workload; and better slag-condensing effect can be achieved by using this slag-condensing pipe, and it is also easier to remove the caking and ash slag condensed on the surface of the slag-condensing pipe;

[0067] In addition, the self-cleaning slag-condensing air distribution disc provided by the present invention can achieve self-cleaning, reducing a large amount of maintenance costs and personnel costs, and the operating cost is lower.

[0068] As described above, the above are only specific embodiments of the present invention, and the scope of the invention implementation cannot be limited by them. Therefore, the replacement of equivalent components or the equivalent changes and modifications made according to the scope of the invention patent protection of the present invention should still fall within the scope covered by this patent. In addition, the technical features in the present invention can be freely combined and used among technical features, between technical features and technical inventions, and between technical inventions.

Claims

1. A slag coagulation pipe, which is used in a self-cleaning slag coagulation air distribution plate, Characterized in that, A number of slag coagulation protrusions are arranged on the outer side wall of the slag coagulation pipe, and the slag coagulation protrusions are used to accelerate slag coagulation; A number of air distribution openings are formed on the outer side wall of the slag coagulation pipe on the side opposite to the number of slag coagulation protrusions, and a number of short pipes are connected to the number of air distribution openings; Wherein, the slag coagulation protrusions are arranged on the outer side wall of the slag coagulation pipe in a longitudinal column form along the circumferential direction of the slag coagulation pipe.

2. The slag coagulation pipe according to claim 1, Characterized in that, The slag coagulation protrusion is a columnar or spherical protrusion.

3. The slag coagulation pipe according to claim 1 or 2, Characterized in that, The material of the slag coagulation pipe is stainless steel.

4. A self-cleaning slag coagulation air distribution plate, Characterized in that, The self-cleaning slag coagulation air distribution plate includes a box body, a number of slag coagulation pipes as described in any one of claims 1-3, and a number of slag removal devices; An inlet and an outlet are respectively formed at both ends of the box body; a number of the slag coagulation pipes are fixed inside the box body in a manner perpendicular to the axis of the box body, and the axis is the axis passing through the inlet of the box body and the outlet of the box body; the inlet and outlet of the slag coagulation pipe are located outside the box body, and the slag coagulation protrusion of the slag coagulation pipe faces the inlet of the box body, and the air distribution opening faces the outlet of the box body; The slag removal device is a device for removing the slag on the surface of the slag coagulation pipe.

5. The self-cleaning slag coagulation air distribution plate according to claim 4, Characterized in that, The slag removal device is movably arranged on the box body, and the slag removal device faces the slag coagulation protrusion of the slag coagulation pipe.

6. The self-cleaning slag coagulation air distribution plate according to claim 4 or 5, Characterized in that, The slag removal device includes a high-pressure water gun.

7. A flue gas treatment system, including a section of heating furnace and the cold side of GGH connected by a pipeline; Characterized in that, The flue gas treatment system further includes a self-cleaning slag coagulation air distribution plate as described in any one of claims 4-6, the self-cleaning slag coagulation air distribution plate is arranged in the pipeline between a section of heating furnace and the cold side of GGH, and the axis passing through the inlet of the box body and the outlet of the box body of the self-cleaning slag coagulation air distribution plate is parallel to the flue gas flow direction; The inlets and outlets of the slag coagulation pipes of the self-cleaning slag coagulation air distribution plate are respectively aggregated and connected to the high-temperature medium main pipe.

8. The flue gas treatment system according to claim 7, Characterized in that, The flue gas treatment system further includes a wet desulfurization device, a demister, a wet electrostatic precipitator, a second-stage heating furnace, a denitration reactor, the hot side of GGH, a booster fan and a chimney, and the wet desulfurization device, the demister, the wet electrostatic precipitator, a section of heating furnace, the cold side of GGH, a second-stage heating furnace, a denitration reactor, the hot side of GGH, a booster fan and a chimney are connected in sequence through pipelines.

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