TWI664281B - Treatment method for reducing fouling on blade of blast furnace top gas recovery turbine unit and apparatus thereof - Google Patents

Abstract

A treatment method and equipment for reducing blade fouling in a furnace top pressure blast furnace gas recovery power generation system, the method includes the steps of: performing a pipeline drainage operation on a spray water supply line of a spray water system; and providing an iron dispersant solution Adding the iron dispersant solution to a spray water of the spray water system; providing a physical antiscalant device to the spray water supply line to disperse an iron-containing substance in the spray water in the spray water to avoid Fouling; and spraying one of the treated water after the above-mentioned treatment step on the blade located at a nozzle of the spraying water supply line.

Description

Treatment method and equipment for reducing blade fouling in furnace top pressure blast furnace gas recovery power generation system

The present invention relates to a method for reducing blade fouling in a furnace top pressure blast furnace gas recovery power generation system, and more particularly, to a method for discharging sewage by a pipeline, adding the iron dispersant solution to a spray water system, and using a physical scale preventer The treatment method of the device reduces the fouling of the blade of the furnace top pressure blast furnace gas recovery power generation system.

The existing blast furnace plant is mainly used for the production of molten iron. With the blast furnace gas produced at the top of the blast furnace, the blast furnace gas then flows through a dust catcher, removes large particles of dust, and then flows through The scrubber system removes some fine dust and further purifies the blast furnace gas. The general demand is to reduce the dust content in the blast furnace gas to 10 mg / NM ³ or even less than 5 mg / NM ³ . The purified blast furnace gas can be used in a blast furnace top gas recovery turbine unit (TRT). It uses a purified blast furnace gas to drive a turbine generator, and then uses the turbine to Drive power generation and recover blast furnace gas, thereby using it as a downstream heat source. Although the dust content in the purified blast furnace gas is less than 10mg / NM ³ , it still contains many dust particles of metal oxides and a little water, which will form a wetting effect on the turbine blades, and therefore adsorb and accumulate metal The oxide dust particles will gradually form hard scales after long-term operation through the furnace top pressure blast furnace gas recovery power generation system. If the dust removal effect of the upstream dust washing water is not good, the dust content of the blast furnace gas will be too high, resulting in excessively thick scale, which will damage the dynamic balance of the TRT device, making the equipment prone to severe jitter and vibration values. If the jitter and vibration values exceed When the control value of the equipment is running, the generator set will automatically trip. At this time, it is necessary to stop the machine for emergency maintenance and use high-pressure waterjet to descale the blade. Therefore, severe scaling on the surface of TRT blades will have the following disadvantages: affecting production smoothness, reducing molten iron output, reducing blast furnace gas recovery, affecting downstream heat source supply, reducing TRT power generation, affecting power costs, and machinery maintenance operations Frequent times and increased labor costs.

The existing treatment methods for reducing blade fouling are mainly applied to anti-scale / descaling methods, which are: (1) setting a spray water system; and (2) adding a scale inhibitor to the spray water system. The main function of the spray water system is to prevent dust from accumulating and adhering to the blade surface by spraying water. However, the descaling effect of this method is not good, and the maintenance frequency must be once every two months. For example, Continental Invention Patent No. 101298841 discloses a method for removing fouling by using a high-pressure waterjet, in which, after every 2 to 2.5 months of operation of the blast furnace TRT equipment, high-pressure waterjet (0.5 To 0.8Mpa) for 2 hours, which can effectively and quickly clean the blades, thereby reducing the downtime of the generator set. However, the above methods still need to be performed for maintenance. Continental Invention Patent No. 101348914 discloses a kind of scaling material on the surface of blast furnace TRT blades. 30% to 40% of organic heterocyclic compounds, 25% to 45% of high-efficiency corrosion inhibitors, 2% to 5% of surfactants, and Scale dispersant, etc. to slow down the formation of scale. Continental Invention Patent No. 102443806 discloses a solution to the problem of scaling on the surface of blast furnace TRT blades, which can add 10% to 20% of bisoctyl / caprylyldimethylammonium chloride, 14% to 20% of dicyclohexylamine and triethanolamine mixture 16% to 20% and diluted with water to prepare a scale inhibitor, the amount of addition is 100ppm to 300ppm, can slow the formation of scale.

However, the above-mentioned existing antiscaling / descaling methods still have the following problems in practical use. For example, a high unit price antiscalant is added to the spray water system, but the effect of dispersing and peeling the scale is not good. Dense scale deposits will still be generated on the TRT blades, and after a long period of operation, it is still necessary to perform shutdown maintenance. In addition, the cost of the medicine is high and when there are too many impurities in the water sprayed, the anti-scaling effect will be greatly reduced.

Therefore, it is necessary to provide a treatment method for reducing blade fouling in the furnace top pressure blast furnace gas recovery power generation system to solve the problems existing in conventional technology.

The main purpose of the present invention is to provide a method for reducing the fouling of the blades of the furnace top pressure blast furnace gas recovery power generation system. Opportunities to improve the stability of TRT power generation equipment.

The secondary objective of the present invention is to provide a method for reducing the fouling of the blades of the furnace top pressure blast furnace gas recovery power generation system, which uses the addition and installation of a physical scale preventer to disperse impurities in the water of the spray water system in the spray water, and further Reduce the chance of scale formation, thus reducing the period of TRT power generation equipment that needs to be shut down for maintenance operations to improve production smoothness and molten iron output, increase blast furnace gas recovery, avoid affecting downstream heat source supply, and increase TRT power generation , And reduce the number of mechanical maintenance operations and labor costs.

In order to achieve the above object, the present invention provides a method for reducing fouling of a blade of a furnace top pressure blast furnace gas recovery power generation system, which includes the steps of: performing a pipeline drainage operation on a spray water supply line of a spray water system; Provide an iron part dispersant solution, and add the iron part dispersant solution to a spray water of the spray water system; provide a physical antiscalant device to the spray water supply line to make an iron-containing substance in the spray water Dispersed in the spray water to avoid fouling; and spraying one of the treated water after the above-mentioned treatment step on the blade positioned at a nozzle of the spray water supply line.

In an embodiment of the present invention, the pipeline drainage operation is to discharge a corner of the spray water supply pipeline to reduce a suspended solid content in the spray water supply pipeline.

In one embodiment of the present invention, the content of the suspended solids in the spray water supply pipeline is reduced to less than 10 mg / liter after the pipeline drainage operation is performed.

In one embodiment of the present invention, the iron dispersant solution includes an organic acid polymer dispersant, an organic acid polymer penetrant, and an organic acid polymer complexing agent.

In one embodiment of the present invention, the weight percentage of the organic acid polymer dispersant in the entire iron dispersant solution is 20% to 30%, and the organic acid polymer penetrant accounts for the entire iron dispersant solution. The weight percentage is 5% to 20%, and the weight ratio of the organic acid polymer complexing agent to the entire iron dispersant solution is 5% to 15%.

In one embodiment of the present invention, the organic acid polymer dispersant is a phosphinocarboxylic acid, and the organic acid polymer dispersant has a molecular weight of 500 to 1000; the organic acid polymer penetrant is a carboxylic acid / A sulfonic acid copolymer, the organic acid polymer penetrant has a molecular weight of 1000 to 1500; and the organic acid polymer complexing agent is a hydroxyethylidene diphosphonic acid, and the organic acid polymer complexing agent has a molecular weight of 500 to 1000.

In one embodiment of the present invention, an addition amount of the iron dispersant solution to the spray water is 10 mg / L to 40 mg / L.

In one embodiment of the present invention, the physical scale preventer device is a permanent magnet, and a magnetic field strength of the physical scale preventer device is 7000 to 8000 Gauss.

The invention also provides a treatment device for reducing blade fouling of a furnace top pressure blast furnace gas recovery power generation system, including: a spray water system having a spray water supply line, the spray water supply line having a pipeline sewage device disposed on the A corner of the spray water supply pipeline; an iron dispersant solution dosing device configured to add an iron dispersant solution to a spray water in the spray water system; and a physical antiscalant device, provided At the periphery of the sprinkler water supply line, an iron-containing substance in the sprinkler water is dispersed in the sprinkler water to avoid scaling; after the physical scale preventer device and the iron dispersant solution are added to the sprinkler water system, One of the treated water is sprayed on the blade located at one of the spray heads of the sprayed water supply line.

S11 ~ S14‧‧‧step

210‧‧‧blast furnace

211‧‧‧ pipeline

220‧‧‧Class I processing equipment

221‧‧‧ Pipeline

230‧‧‧ Dust washing water system

231‧‧‧ Pipeline

240‧‧‧ Turbine Unit

241‧‧‧ Blade

242‧‧‧ Pipeline

243‧‧‧Nozzle

250‧‧‧Sprinkling water system

251‧‧‧Spray water storage tank

252‧‧‧Spray water supply pipeline

253‧‧‧pipeline drainage device

254‧‧‧Sewage pipeline

255‧‧‧Sewage valve

256‧‧‧iron dispersant solution dosing device

257‧‧‧iron dispersant solution storage tank

258‧‧‧Dosing pump

259‧‧‧ physical antiscalant device

FIG. 1 is a flow block diagram of a method for reducing blade fouling in a furnace top pressure blast furnace gas recovery power generation system according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of a treatment device for reducing blade fouling in a furnace top pressure blast furnace gas recovery power generation system according to the first embodiment of the present invention.

In order to make the above and other objects, features, and advantages of the present invention more comprehensible, the following describes the preferred embodiments of the present invention and the accompanying drawings in detail, as follows. Furthermore, the directional terms mentioned in the present invention include, for example, top, bottom, top, bottom, front, back, left, right, inside, outside, side, periphery, center, horizontal, horizontal, vertical, vertical, axial, The radial direction, the uppermost layer, or the lowermost layer, etc., are only directions referring to the attached drawings. Therefore, the directional terms used are for explaining and understanding the present invention, but not for limiting the present invention.

Please refer to FIG. 1. The method for reducing fouling of the blades of the blast furnace gas recovery power generation system according to the first embodiment of the present invention mainly includes the following steps: (S11) A spray water supply line for a spray water system Performing a pipeline sewage operation; (S12) providing an iron dispersant solution, and adding the iron dispersant solution to a spray water of the spray water system; (S13) providing a substance A rational antiscalant device is installed on the spray water supply line to disperse an iron-containing substance in the spray water into the spray water to avoid scaling; and (S14) spray one of the treated water after the above processing steps is in place On the blade at one of the spray heads of the spray water supply line. The present invention will use the first and second figures below to explain in detail the implementation details of the above steps of the first embodiment, corresponding processing equipment and its principle.

Please refer to FIG. 1 and in conjunction with FIG. 2, the method for reducing blade fouling of the blast furnace gas recovery power generation system according to the first embodiment of the present invention is firstly: (S11) to a spray water system 250 The spray water supply line 252 performs a pipeline drainage operation. In this step, after the blast furnace 210 of a blast furnace plant produces molten iron, along with the top of the blast furnace 210, a high amount of blast furnace gas with a high amount of dust is produced. The blast furnace gas then flows into a dust catcher through a line 211 220, such as a cyclone dust collector, to remove large particles of dust. Then, it flows into a scrubber system 230, such as a Venturi scrubber, through a line 221 to remove a part of the fine dust, thereby further purifying the blast furnace gas. The general requirement is to reduce the dust content in the blast furnace gas to 10 mg / NM ³ . The purified blast furnace gas is passed into a blast furnace top gas recovery turbine unit (TRT) through a line 231, and the purified blast furnace gas is used to drive a turbine generator 240 One of the blades 241 is used to drive the blade 241 to rotate so that the turbine unit 240 generates electricity and uses a pipeline 242 to recover blast furnace gas, thereby using it as a downstream heat source. Although the dust content in the purified blast furnace gas is less than 10 mg / NM ³ , it still contains many dust particles of metal oxides and a little water. The little water will form a wetting effect on the blades 241 of the turbine unit 240 and Therefore, after the metal oxide dust particles are adsorbed and accumulated, after a long-term operation of the furnace top pressure blast furnace gas recovery power generation system, scales will gradually form. Therefore, a spray water system 250 is provided in the turbine unit 240 with a spray water supply line 252, a spray water storage tank 25, and a spray water. The spray water supply line 252 has a spray head 243 disposed in the turbine unit 240 to The blade 241 is sprayed and decontaminated. A pipeline drain device 253 is disposed at a corner of the spray water supply line 252. The pipeline drain device 253 has a drain line 254 and a drain valve 255 to perform a spray water supply line 252 on the spray water system 250. In the pipeline drainage operation, the corner of the spray water supply line 252 is drained to eliminate sludge accumulated at the corner of the spray water supply line 252 and reduce a suspended solid in the spray water supply line 252 (Suspended Solids, SS). In this embodiment, the blowdown operation is a blowdown operation for 24 hours. The blowdown valve 255 is opened for about 30 seconds to remove impurities in the water. According to the test results of this embodiment, the blowdown valve 255 is closed after the blowdown operation. In this way, the suspended solids in the spraying water can be reduced from 15 ± 5mg / L to less than 2mg / L. This can initially improve the cleanliness of the water quality, stabilize the spraying water volume and water pressure, and make the system run smoothly, thereby reducing the blade. 241 probability of iron oxide adhesion.

Please refer to FIG. 1 and in conjunction with FIG. 2, the method for reducing fouling of the blades of the blast furnace gas recovery power generation system of the first embodiment of the present invention is as follows: (S12) providing an iron dispersant solution, The iron dispersant solution was added to a spray water of the spray water system 250. The iron dispersant solution is sprayed with water by an iron dispersant solution dosing device 256. The iron dispersant solution is stored in an iron dispersant solution storage tank 257, and a certain amount of dosing pump is turned on The pump 258 is actuated to add the iron dispersant solution to the spray water system 250 to complete the spraying of the spray water. In this embodiment, the iron dispersant solution is added to the spray water system 250 so that the concentration of the iron dispersant solution in the spray water is greater than 10 mg / L. In a preferred embodiment, the iron dispersant solution is added to the spray water in an amount of 10 mg / L to 40 mg / L. In this embodiment, the iron dispersant solution includes an organic acid polymer dispersant, an organic acid polymer penetrant, and an organic acid polymer complexing agent. The organic acid polymer dispersant accounts for 20% to 30% by weight of the entire iron dispersant solution, and the organic acid polymer penetrant accounts for 5% to 20% of the entire iron dispersant solution by weight. And the weight percentage of the organic acid polymer complexing agent to the entire iron dispersant solution is 5% to 15%. In this embodiment, the organic acid polymer dispersant is a phosphinocarboxylic acid, the organic acid polymer dispersant has a molecular weight of 500 to 1000, and the organic acid polymer penetrant is a carboxylic acid / sulfonic acid copolymerization. A molecular weight of the organic acid polymer penetrant is 1000 to 1500; and the organic acid polymer complexing agent is monohydroxyethylidene diphosphonic acid, and a molecular weight of the organic acid polymer complexing agent is 500 to 1,000. The following table 1 shows the composition of the iron dispersant solution in the first embodiment of the present invention:

Please refer to FIG. 1 and in conjunction with FIG. 2, the treatment method for reducing blade fouling in the first embodiment of the present invention is as follows: (S13) A physical scale preventer device 259 is provided in the spray water supply line 252, Therefore, an iron-containing substance in the spray water is dispersed in the spray water to avoid scaling. The physical scale preventer device 259 is disposed on the periphery of the spray water supply line, so that an iron-containing substance in the spray water is dispersed in the spray water to avoid scaling. In this embodiment, the physical antiscalant device 259 is a permanent magnet. In this embodiment, a magnetic field strength of the physical scale preventer device 259 is 7000 to 8000 Gauss. In this embodiment, the physical scale preventer device 259 is composed of four groups of eight, which are symmetrically arranged on both sides of the spray water supply line 252. In this embodiment, the physical antiscalant device 252 is mainly composed of Nd / Fe / B and a magnetically permeable material of medium and low carbon steel. The physical scale preventer device 259 can make the magnetic field penetrate the pipe wall of the spray water supply line 252, so that the substance causing the blade scaling is dispersed in the water, thereby reducing the scaling caused by spraying on the blade or making the scaling loose. Structure, not a dense scale structure. The treated water after one of the treatment steps is sprayed on the blade 241 located at the spray head 243 of the sprayed water supply line 252.

The following table 2 shows the effect on blade vibration value and power generation efficiency after using the first embodiment of the present invention:

In summary, the present invention can reduce the content of suspended solids in spray water, and uses an iron dispersant solution and a physical antiscalant device to disperse the scale-causing substances in the water, so that the spray water sprayed on the blades can be avoided Fouling, or a loosely formed scale layer, can be easily removed. This can reduce the period of downtime maintenance operations required for TRT power generation equipment to improve production smoothness and molten iron output, increase blast furnace gas recovery, avoid affecting downstream heat source supply, increase TRT power generation, and reduce machinery maintenance Number of operations and labor costs.

Although the present invention has been disclosed in a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. The scope of protection shall be determined by the scope of the attached patent application.

Claims (6)

A treatment method for reducing fouling of a blade of a furnace top pressure blast furnace gas recovery power generation system includes the steps of: performing a pipeline drainage operation on a spray water supply line of a spray water system; providing an iron dispersant solution, The iron dispersant solution is added to a spray water of the spray water system, wherein the iron dispersant solution includes an organic acid polymer dispersant, an organic acid polymer penetrant, and an organic acid polymer complexing agent, and the The organic acid polymer dispersant accounts for 20% to 30% by weight of the entire iron dispersant solution, the organic acid polymer penetrant accounts for 5% to 20% by weight of the entire iron dispersant solution, and The organic acid polymer complexing agent accounts for 5% to 15% by weight of the entire iron dispersant solution; a physical antiscalant device is provided in the spray water supply line to make an iron-containing substance in the spray water Dispersed in the spray water to avoid fouling; and spraying one of the treated water after the above-mentioned treatment step on the blade located at a nozzle of the spray water supply line, wherein the physical The antiscalant device uses four groups of eight permanent magnets with a magnetic field intensity of 7000 to 8000 Gauss symmetrically arranged on both sides of the spray water supply pipeline. The method for reducing the fouling of the blades of the blast furnace gas recovery power generation system as described in item 1 of the scope of the patent application, wherein the pipeline drainage operation is to discharge a corner of the spray water supply pipeline to reduce the spray. Content of a suspended solid in a water supply line. The method for reducing fouling of the blades of the blast furnace gas recovery power generation system as described in item 2 of the scope of the patent application, wherein the suspended solid content in the spray water supply pipeline is reduced to less than 10 after the pipeline drainage operation is performed. Mg / litre. The method for reducing blade fouling in a blast furnace gas recovery power generation system according to item 1 of the scope of the patent application, wherein the organic acid polymer dispersant is a monophosphonic carboxylic acid, and the organic acid polymer dispersant is A molecular weight of 500 to 1000; the organic acid polymer penetrant is a carboxylic acid / sulfonic acid copolymer, the organic acid polymer penetrant has a molecular weight of 1000 to 1500; and the organic acid polymer complexing agent is a hydroxyl group Ethylene diphosphonic acid, the organic acid polymer complexing agent has a molecular weight of 500 to 1,000. The method for reducing blade fouling in a furnace top pressure blast furnace gas recovery power generation system according to item 1 of the scope of patent application, wherein one of the iron dispersant solution is added to the spray water at an amount of 10 mg / liter to 40 Mg / L. A treatment device for reducing blade fouling of a furnace top pressure blast furnace gas recovery power generation system includes: a spray water system having a spray water supply line, the spray water supply line having a pipeline drainage device arranged on the spray water supply A corner of the pipeline; an iron dispersant solution dosing device configured to add an iron dispersant solution to a spray water in the spray water system, wherein the iron dispersant solution contains an organic acid polymer dispersion Agent, an organic acid polymer penetrant and an organic acid polymer complexing agent, and the weight percentage of the organic acid polymer dispersant in the total iron dispersant solution is 20% to 30%, and the organic acid polymer permeates The weight percentage of the iron dispersant solution in the whole is 5% to 20%, and the weight percentage of the organic acid polymer complexing agent in the total iron dispersant solution is 5% to 15%; and A scale device is arranged at the periphery of the spray water supply line to disperse an iron-containing substance in the spray water in the spray water to avoid scaling; the physical scale preventer device and After the iron dispersant solution is added to the spray water system, one of the treated water is sprayed on the blade located at one of the spray heads of the spray water supply line, wherein the physical scale preventer device uses four groups of eight symmetrically. Permanent magnets with a magnetic field strength of 7000 to 8000 Gauss are arranged on both sides of the spray water supply pipeline.