Device for generating coke breeze for blast furnace injection through pyrolysis of feed coal

Abstract

The utility model provides a device for generating coke breeze for blast furnace injection by pyrolyzing feed coal, which comprises a feeding unit, a pyrolyzing and separating unit, a heat carrier heating unit and a blast furnace injection separating unit which are sequentially connected, the pyrolysis and separation unit is divided into a pyrolysis reaction area and a gas-solid separation area, a solid outlet of the gas-solid separation area is connected with the heat carrier heating unit, an upper outlet of the heat carrier heating unit is connected with the blast furnace injection separation unit, and the blast furnace injection separation unit is used for extracting coke breeze for blast furnace injection. Through the arrangement of the washing and grinding device, the granularity of feed coal is controlled, the ash content in the feed coal is reduced, coke breeze is heated after pyrolytic reaction, the ash content of the coke breeze is reduced, and the granularity of the coke breeze is controlled through separation, so that the coke breeze can meet the use requirements of blast furnace injection materials, and the utilization value of low-rank coal and coke breeze products is improved; the device is simple in structure, easy and convenient to operate, low in cost, high in economic benefit and wide in application range.

Description

Technical Field

[0001] The utility model belongs to the technical field of powdered coke production and high-value utilization, and relates to a device for generating powdered coke for blast furnace injection by pyrolyzing raw coal. Background Art

[0002] Blast furnace smelting is an important technology in the metallurgical industry. The selection of blast furnace injection material is a prerequisite for the efficient blast furnace smelting, and has a significant impact on the development of the metallurgical industry. In the traditional blast furnace smelting process, coke is usually used as the blast furnace injection material. In recent years, due to the high price and shortage of coke resources, the direct use of pulverized coal as blast furnace injection material has developed rapidly in the metallurgical industry. Although my country's energy structure is rich in coal resources, the requirements for pulverized coal as blast furnace injection material are relatively strict, including low ash content, low viscosity, low sulfur content, good grindability, high combustibility and high ash melting point. Therefore, the coal type for blast furnace injection is mainly anthracite, but anthracite has a low proportion in coal resources and a high price. In addition, during the application process, the particle size and moisture of pulverized coal need to be controlled, resulting in a high cost investment in the application of blast furnace injection coal and a large consumption of high-rank coal. Based on this, actively developing the technology of low-rank coal as blast furnace injection coal is one of the current research directions.

[0003] At present, pulverized coal pyrolysis is an important research direction in coal utilization technology. The pyrolysis products mainly include coal gas, coal tar and powdered coke, which have the advantages of low energy consumption and low carbon emissions. The first two can be used as high value-added chemicals and oils, while the powdered coke product has the characteristics of small particle size, low moisture, low volatile matter and low sulfur, which are similar to the performance requirements of blast furnace pulverized coal. Based on the source of pulverized coal, if powdered coke is produced with low-rank coal as raw material, the cost of powdered coke can be effectively reduced, giving it a price advantage, thereby improving the economy of blast furnace smelting.

[0004] CN 102952557A discloses a method for preparing fuel and coal tar for blast furnace injection, the method comprising: countercurrent drying raw coal to obtain dehydrated and de-pulverized coal, placing the dehydrated and de-pulverized coal in a dry distillation furnace for dry distillation and pyrolysis reaction to obtain the fuel for blast furnace injection and a mixed gas of coal tar and coal gas. In the method, the raw coal is directly dry-distilled and pyrolyzed after being dried, the processing of the raw material is relatively simple, the particle size requirement is not clear, and the powdered coke produced by pyrolysis is not further processed. When low-rank coal is used as raw material, the powdered coke product generated is difficult to meet the requirements of powdered coke for blast furnace injection. If the particle size requirement for blast furnace injection needs to be met, further grinding is required, and the powdered coke produced has a low grindability index and high energy consumption for grinding.

[0005] CN 107794069A discloses a segmented coking method of a pyrolysis and coking system of powder containing carbon and hydrogen elements. The method is suitable for the processing of pulverized coal. The pulverized coal pyrolysis product using the first solid heat carrier is separated into a section of coal gas and a section of semi-coke by a separation section using a cyclone separator arranged in a settler. Finally, the pyrolysis semi-coke is discharged from the pyrolysis reaction process and enters the fluidized bed coking reaction space, and contacts with the oxygen-containing gas flowing from bottom to top to produce a fluidized bed coking reaction to generate high-temperature oxidized semi-coke and flue gas; at least a part of the high-temperature oxidized semi-coke discharged from the fluidized bed coking reaction process is used as the first solid heat carrier. The fluidized bed coking reaction process is provided with two coking steps. According to the expected particle size distribution of the first solid heat carrier, semi-coke fine powder or semi-coke coarse powder is preferentially burned. The method adopts the traditional method of burning the powdered coke produced by pyrolysis to obtain a high-temperature heat carrier, and does not involve the use of it as a blast furnace injection material, and naturally does not involve how to process the powdered coke to meet the use requirements of blast furnace injection materials.

[0006] In summary, for the equipment and process for preparing powdered coke for blast furnace injection by pyrolysis of raw coal, especially using low-rank coal as raw material, the raw coal is pretreated and the powdered coke generated by pyrolysis is further treated to make it meet the use requirements of blast furnace injection materials, so as to improve the high-value utilization of low-rank coal resources. Utility Model Content

[0007] In view of the problems existing in the prior art, the purpose of the utility model is to provide a device for pyrolyzing raw coal to generate powdered coke for blast furnace injection, wherein the device controls the particle size of the raw coal and reduces the ash content in the raw coal by setting up washing and grinding devices, and then heats the powdered coke instead of burning it after the pyrolysis reaction, thereby effectively reducing the ash content of the powdered coke, and then controls the particle size of the powdered coke through separation, so that the powdered coke can meet the use requirements of blast furnace injection materials, improve the utilization value of low-rank coal resources, and solve the problem of powdered coke utilization.

[0008] To achieve this purpose, the utility model adopts the following technical solutions:

[0009] The utility model provides a device for pyrolyzing raw coal to generate powdered coke for blast furnace injection. The device comprises a feeding unit, a pyrolysis and separation unit, a heat carrier heating unit and a blast furnace injection separation unit connected in sequence. The feeding unit comprises a washing device and a grinding device in sequence. The pyrolysis and separation unit is divided into a pyrolysis reaction zone and a gas-solid separation zone from bottom to top. The solid outlet of the gas-solid separation zone is connected to the inlet of a heat carrier heating unit. A flue gas inlet is provided at the bottom of the heat carrier heating unit. The upper outlet of the heat carrier heating unit is connected to the inlet of a blast furnace injection separation unit. The lower outlet of the blast furnace injection separation unit extracts powdered coke for blast furnace injection.

[0010] In the utility model, since the blast furnace injection material has high performance requirements on coal resources, in order to reduce the requirements of the blast furnace injection material on the type of coal, the characteristics of the powdered coke after coal pyrolysis are utilized, and the raw coal and the utilization process are improved so that the characteristics of the powdered coke product meet the performance requirements of the blast furnace injection material; the utility model controls the particle size and ash content of the raw coal by setting up a washing and grinding device, and then heats the obtained powdered coke product after passing through a pyrolysis and separation unit to avoid the problem of high ash content caused by the combustion of the powdered coke. While reducing the ash content, the particle size of the separated powdered coke is controlled by setting up a blast furnace injection separation unit, so that the ash content and particle size performance of the separated powdered coke can meet the performance requirements of the blast furnace injection material, and effectively improve the utilization value of low-rank coal resources and powdered coke products; the device has a simple structure, is easy to operate, has a low cost, high economic benefit, and a wide range of applications.

[0011] The following are preferred technical solutions of the present invention, but are not intended to be limitations of the technical solutions provided by the present invention. Through the following technical solutions, the technical objectives and beneficial effects of the present invention can be better achieved and realized.

[0012] As a preferred technical solution of the utility model, the washing device comprises a screening device and a concentrating cyclone device in sequence, the screened material of the screening device enters the concentrating cyclone device, and the bottom outlet of the concentrating cyclone device is connected to the inlet of the grinding device.

[0013] In the utility model, the selection of the washing device is mainly for screening the raw coal. By selecting the screening equipment and the concentrating cyclone equipment, the ash content of the raw coal can be reduced.

[0014] Preferably, the grinding device comprises a coal mill, a protective gas is introduced into the grinding device for drying the pulverized coal, and the protective gas comprises an inert gas.

[0015] In the utility model, the raw coal is added to a coal mill after being washed, ground into powder by a grinding roller, and dried by a high-temperature protective gas, wherein the protective gas may be an inert gas or the like.

[0016] Preferably, the feeding unit further comprises a raw material tank, the outlet of the grinding device is connected to the inlet of the raw material tank, and the outlet of the raw material tank is connected to the inlet of the pyrolysis reaction zone.

[0017] Preferably, the feeding unit further comprises a circulating gas pipeline, and the circulating gas pipeline is connected to the inlet of the pyrolysis reaction zone after merging with the outlet pipeline of the raw material tank.

[0018] Preferably, a first gas-solid separator is provided in the raw material tank, and the first gas-solid separator comprises a cyclone separator and / or a bag filter.

[0019] In the utility model, the protective gas transports the dried pulverized coal to the raw material tank, and most of the pulverized coal is separated by a gas-solid separator in the raw material tank, such as a cyclone separator, and the remaining pulverized coal particles can be collected by a bag filter and also sent to the raw material tank.

[0020] As a preferred technical solution of the utility model, the pyrolysis and separation unit includes an empty barrel reactor, the lower part of the empty barrel reactor is a pyrolysis reaction zone, the upper part is a gas-solid separation zone, and the pyrolysis reaction zone and the gas-solid separation zone are connected.

[0021] Preferably, at least one second gas-solid separator is provided in the gas-solid separation zone, such as one, two or three stages, and the second gas-solid separator includes a cyclone separator.

[0022] Preferably, a solid outlet is provided on the lower side wall of the gas-solid separation zone, and the lower outlet of the second gas-solid separator extends to the solid outlet of the gas-solid separation zone.

[0023] Preferably, the device further comprises a fractionation unit, the gas outlet of the gas-solid separation zone is connected to the inlet of the fractionation unit, and different outlets of the fractionation unit respectively obtain coal tar and coal gas.

[0024] As a preferred technical solution of the utility model, the solid outlet of the gas-solid separation zone is connected to the lower inlet of the heat carrier heating unit through a heat carrier circulation pipe.

[0025] Preferably, the heat carrier heating unit comprises a heat carrier heater, a third gas-solid separator is provided in the heat carrier heating unit, and the third gas-solid separator comprises a cyclone separator.

[0026] In the utility model, after the solid powdered coke generated by the pyrolysis reaction enters the heat carrier heater, it is heated by the high-temperature flue gas to reduce the volatile content; after the powdered coke is heated by the flue gas, the separation particle size of the powdered coke is controlled by the setting of the gas-solid separator inside it, so that the particle size of the powdered coke leaving with the flue gas can meet the requirements of blast furnace injection.

[0027] Preferably, a solid outlet is provided at the bottom of the heat carrier heating unit, and the solid outlet is connected to the inlet of the pyrolysis reaction zone.

[0028] Preferably, the device further comprises a smoke generator, and the smoke generator is provided with a fuel oil inlet or a circulating gas inlet, an air inlet and a smoke outlet, and the smoke outlet is connected to the smoke inlet of the heat carrier heating unit.

[0029] As a preferred technical solution of the utility model, the blast furnace blowing separation unit includes a blast furnace blowing separator, and the blast furnace blowing separator includes at least one stage of cyclone separator, such as one stage, two stages or three stages.

[0030] Preferably, the blast furnace injection separator further comprises a precision filter, and the precision filter comprises a sintered metal filter.

[0031] Preferably, the blast furnace injection separation unit further comprises a blast furnace injection cooler, the lower outlet of the blast furnace injection separator is connected to the inlet of the blast furnace injection cooler, and the outlet of the blast furnace injection cooler extracts powdered coke for blast furnace injection.

[0032] Preferably, the device further comprises a fume recovery unit, and the gas outlet of the blast furnace injection separator is connected to the inlet of the fume recovery unit.

[0033] The utility model also provides a method for producing powdered coke for blast furnace injection by using the above device, the method comprising the following steps:

[0034] (1) washing and grinding the raw coal and then subjecting it to pyrolysis reaction, and separating the pyrolysis product into solid powdered coke through gas-solid separation;

[0035] (2) The solid coke powder obtained in step (1) is heated by flue gas, and part of the coke powder is separated from the flue gas by blast furnace injection to obtain coke powder for blast furnace injection.

[0036] As a preferred technical solution of the utility model, the raw coal in step (1) includes low-rank coal, and the low-rank coal includes any one of lignite, long flame coal, non-sticky coal or weakly sticky coal, or a combination of at least two of them. Typical but non-limiting examples of the combination include: a combination of lignite and long flame coal, a combination of long flame coal and non-sticky coal, a combination of long flame coal, non-sticky coal and weakly sticky coal, a combination of lignite, long flame coal and non-sticky coal, a combination of lignite, long flame coal, non-sticky coal and weakly sticky coal, etc.

[0037] Preferably, the washing in step (1) includes screening and cyclone washing in sequence.

[0038] Preferably, the pulverized coal formed after grinding is dried using protective gas, and the temperature of the protective gas is 150-350°C, for example, 150°C, 180°C, 200°C, 220°C, 250°C, 280°C, 300°C, 320°C or 350°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0039] Preferably, the ash content of the pulverized coal obtained by washing and grinding in step (1) is less than 7%, for example, 7%, 6.5%, 6%, 5.5%, 5%, 4.5%, 4%, 3.5% or 3%, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are equally applicable; the proportion of particles with a particle size greater than 90 μm does not exceed 55%, for example, 55%, 52%, 50%, 48%, 45%, 42%, 40% or 35%, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are equally applicable.

[0040] Preferably, the pulverized coal is mixed with the circulating coal gas and then enters the pyrolysis reaction zone.

[0041] Preferably, the mass volume ratio of the pulverized coal to the circulating gas is 1 to 4, for example, 1, 1.5, 2, 2.5, 3, 3.5 or 4, but is not limited to the listed values, and other values ​​not listed within the numerical range are equally applicable; the temperature of the circulating gas is 40 to 450°C, for example, 40°C, 60°C, 80°C, 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C or 450°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are equally applicable.

[0042] As a preferred technical solution of the present invention, the temperature of the pyrolysis reaction in step (1) is 500-600°C, for example, 500°C, 520°C, 550°C, 560°C, 580°C or 600°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0043] Preferably, the pressure of the pyrolysis reaction in step (1) is 0 to 0.8 MPaG, for example, 0, 0.1 MPaG, 0.2 MPaG, 0.3 MPaG, 0.4 MPaG, 0.5 MPaG, 0.6 MPaG, 0.7 MPaG or 0.8 MPaG, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0044] Preferably, the time of the pyrolysis reaction in step (1) is 0.5 to 5 s, for example 0.5 s, 1 s, 1.5 s, 2 s, 2.5 s, 3 s, 3.5 s, 4 s, 4.5 s or 5 s, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0045] Preferably, the gas-solid separation in step (1) includes cyclone separation, which is performed at least once, for example, once, twice or three times.

[0046] Preferably, the gas phase product of the gas-solid separation in step (1) is pyrolysis oil gas, which is fractionated to obtain coal tar and coal gas, and part of the coal gas is returned to step (1) for use as a gas heat carrier.

[0047] In the utility model, through the rapid pyrolysis of pulverized coal, while generating pulverized coke, high-yield coal tar can also be produced, reaching a yield of more than 155% of tar, thereby maximizing the utilization of low-rank coal resources; using circulating coal gas as a gas heat carrier for pyrolysis of pulverized coal can accelerate heat transfer, effectively utilize the heat of coal gas, and improve product yield and quality.

[0048] As a preferred technical solution of the utility model, the solid coke powder in step (2) enters the heat carrier heater and is heated by the flue gas, and the temperature of the flue gas is 650-1100°C, for example, 650°C, 680°C, 700°C, 720°C, 750°C, 800°C, 850°C, 900°C, 950°C, 1000°C or 1100°C, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0049] Preferably, the flue gas is generated by the combustion of fuel oil or circulating coal gas.

[0050] In the utility model, the heat of the heat carrier heater is provided by the flue gas generated by the combustion of fuel oil or circulating coal gas as fuel in the flue gas generator, and the reaction conditions for the generation of blast furnace sprayed coke can be adjusted by controlling the flue gas temperature and speed, thereby adjusting the performance of the coke.

[0051] Preferably, gas-solid separation is carried out in the heat carrier heater, and part of the heated coke powder leaves with the flue gas, and the proportion of this part of coke powder is 50-70%, for example, 50%, 55%, 58%, 60%, 62%, 65%, 68% or 70%, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0052] Preferably, the proportion of particles with a particle size greater than 90 μm in the coke leaving with the flue gas is not more than 25%, for example, 25%, 22%, 20%, 18%, 15%, 12% or 10%, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable; the ash content is not more than 12%, for example, 12%, 11.5%, 11%, 10.5%, 10%, 9.5%, 9%, 8.5% or 8%, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0053] As a preferred technical solution of the utility model, the powdered coke that does not leave with the flue gas in step (2) is returned to step (1) as a solid heat carrier to be mixed with the pulverized coal. The temperature of this part of the powdered coke is 600-900°C, for example, 600°C, 650°C, 700°C, 750°C, 800°C, 850°C or 900°C, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0054] Preferably, the blast furnace separation method in step (2) includes cyclone separation and / or precision filtration, and the precision filtration includes sintered metal filtration.

[0055] Preferably, the powdered coke for blast furnace injection obtained by the blast furnace injection separation in step (2) is directly used for blast furnace smelting or stored after cooling.

[0056] In the utility model, the powdered coke for blast furnace injection can be directly transported to the ironmaking furnace at high temperature, or can be transported to the blast furnace injection furnace after being cooled and stored.

[0057] Preferably, the flue gas obtained by blast furnace injection separation in step (2) is discharged after flue gas recovery.

[0058] Compared with the prior art, the utility model has the following beneficial effects:

[0059] (1) The device of the utility model controls the particle size of the raw coal and reduces the ash content in the raw coal by setting up washing and grinding devices, and then heats the powdered coke instead of burning it after the pyrolysis reaction, effectively reducing the ash content of the powdered coke, and then controls the particle size of the powdered coke by separation, so that the proportion of particles with a particle size greater than 90 μm for blast furnace injection is no more than 25%, and the ash content is no more than 12%, which can meet the use requirements of blast furnace injection materials and effectively improve the utilization value of low-rank coal resources and powdered coke products;

[0060] (2) The utility model can generate coal tar and coal gas products while generating powdered coke for blast furnace injection, and the coal tar yield can reach more than 17%;

[0061] (3) The device described in the utility model has a simple structure, is easy to operate, has a low cost, high economic benefit, and a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 This is a schematic diagram of the structure of a device for pyrolyzing raw coal to generate powdered coke for blast furnace injection provided in Example 1 of the utility model;

[0063] Among them, 1-washing device, 2-grinding device, 3-raw material tank, 4-pyrolysis reaction zone, 5-gas-solid separation zone, 6-second gas-solid separator, 7-heat carrier circulation pipe, 8-heat carrier heater, 9-third gas-solid separator, 10-flue gas generator, 11-blast furnace injection separator, 12-blast furnace injection cooler, 13-flue gas recovery unit, 14-distillation unit. DETAILED DESCRIPTION

[0064] In order to better illustrate the utility model and facilitate understanding of the technical solution of the utility model, the utility model is further described in detail below. However, the following embodiments are only simple examples of the utility model and do not represent or limit the scope of protection of the utility model. The scope of protection of the utility model shall be subject to the claims.

[0065] The following are typical but non-limiting embodiments of the present invention:

[0066] Embodiment 1:

[0067] This embodiment provides a device for pyrolyzing raw coal to generate powdered coke for blast furnace injection, and the structural schematic diagram of the device is shown in FIG. Figure 1 As shown, it includes a feeding unit, a pyrolysis and separation unit, a heat carrier heating unit and a blast furnace injection separation unit connected in sequence, the feeding unit includes a washing device 1 and a grinding device 2 in sequence, the pyrolysis and separation unit is divided into a pyrolysis reaction zone 4 and a gas-solid separation zone 5 from bottom to top, the solid outlet of the gas-solid separation zone 5 is connected to the inlet of the heat carrier heating unit, the lower part of the heat carrier heating unit is provided with a flue gas inlet, the upper outlet of the heat carrier heating unit is connected to the inlet of the blast furnace injection separation unit, and the lower outlet of the blast furnace injection separation unit extracts powdered coke for blast furnace injection.

[0068] The washing and selecting device 1 comprises a screening device and a concentrating cyclone device in sequence. The screened material of the screening device enters the concentrating cyclone device, and the bottom outlet of the concentrating cyclone device is connected to the inlet of the grinding device 2.

[0069] The grinding device 2 includes a coal mill, and a protective gas is introduced into the grinding device 2 for drying the pulverized coal. The protective gas is argon.

[0070] The feeding unit further comprises a raw material tank 3 , the outlet of the grinding device 2 is connected to the inlet of the raw material tank 3 , and the outlet of the raw material tank 3 is connected to the inlet of the pyrolysis reaction zone 4 .

[0071] The feeding unit further includes a circulating gas pipeline, which is connected to the inlet of the pyrolysis reaction zone 4 after merging with the outlet pipeline of the raw material tank 3 .

[0072] The raw material tank 3 is provided with a first gas-solid separator, which includes a cyclone separator and a bag filter.

[0073] The pyrolysis and separation unit comprises an empty barrel reactor, the lower part of the empty barrel reactor is a pyrolysis reaction zone 4, and the upper part is a gas-solid separation zone 5, and the pyrolysis reaction zone 4 and the gas-solid separation zone 5 are connected.

[0074] The gas-solid separation zone 5 is provided with a two-stage second gas-solid separator 6 , and the second gas-solid separator 6 is a cyclone separator.

[0075] A solid outlet is provided on the lower side wall of the gas-solid separation zone 5 , and a lower outlet of the second gas-solid separator 6 extends to the solid outlet of the gas-solid separation zone 5 .

[0076] The device further comprises a fractionation unit 14, the gas outlet of the gas-solid separation zone 5 is connected to the inlet of the fractionation unit 14, and different outlets of the fractionation unit 14 respectively obtain coal tar and coal gas.

[0077] The solid outlet of the gas-solid separation zone 5 is connected to the lower inlet of the heat carrier heating unit through the heat carrier circulation pipe 7 .

[0078] The heat carrier heating unit comprises a heat carrier heater 8. A third gas-solid separator 9 is arranged in the heat carrier heating unit. The third gas-solid separator 9 is a cyclone separator.

[0079] A solid outlet is provided at the bottom of the heat carrier heating unit, and the solid outlet is connected to the inlet of the pyrolysis reaction zone 4 .

[0080] The device further comprises a smoke generator 10, on which a fuel oil inlet, an air inlet and a smoke outlet are arranged, and the smoke outlet is connected to the smoke inlet of the heat carrier heating unit.

[0081] The blast furnace spray separation unit includes a blast furnace spray separator 11, and the blast furnace spray separator 11 includes a two-stage cyclone separator and a sintered metal filter.

[0082] The blast furnace injection separation unit further comprises a blast furnace injection cooler 12, the lower outlet of the blast furnace injection separator 11 is connected to the inlet of the blast furnace injection cooler 12, and the outlet of the blast furnace injection cooler 12 extracts powdered coke for blast furnace injection.

[0083] The device further comprises a fume recovery unit 13 , and the gas outlet of the blast furnace injection separator 11 is connected to the inlet of the fume recovery unit 13 .

[0084] Embodiment 2:

[0085] The present embodiment provides a device for pyrolyzing raw coal to generate powdered coke for blast furnace injection, the device comprising a feeding unit, a pyrolysis and separation unit, a heat carrier heating unit and a blast furnace injection separation unit connected in sequence, the feeding unit comprises a washing device 1 and a grinding device 2 in sequence, the pyrolysis and separation unit is divided into a pyrolysis reaction zone 4 and a gas-solid separation zone 5 from bottom to top, the solid outlet of the gas-solid separation zone 5 is connected to the inlet of the heat carrier heating unit, the lower part of the heat carrier heating unit is provided with a flue gas inlet, the upper outlet of the heat carrier heating unit is connected to the inlet of the blast furnace injection separation unit, and the lower outlet of the blast furnace injection separation unit extracts powdered coke for blast furnace injection.

[0086] The washing and selecting device 1 comprises a screening device and a concentrating cyclone device in sequence. The screened material of the screening device enters the concentrating cyclone device, and the bottom outlet of the concentrating cyclone device is connected to the inlet of the grinding device 2.

[0087] The grinding device 2 includes a coal mill, and a protective gas is introduced into the grinding device 2 for drying the pulverized coal. The protective gas is nitrogen.

[0088] The feeding unit further comprises a raw material tank 3 , the outlet of the grinding device 2 is connected to the inlet of the raw material tank 3 , and the outlet of the raw material tank 3 is connected to the inlet of the pyrolysis reaction zone 4 .

[0089] The feeding unit further includes a circulating gas pipeline, which is connected to the inlet of the pyrolysis reaction zone 4 after merging with the outlet pipeline of the raw material tank 3 .

[0090] The raw material tank 3 is provided with a first gas-solid separator, and the first gas-solid separator includes a cyclone separator.

[0091] The pyrolysis and separation unit comprises an empty barrel reactor, the lower part of the empty barrel reactor is a pyrolysis reaction zone 4, and the upper part is a gas-solid separation zone 5, and the pyrolysis reaction zone 4 and the gas-solid separation zone 5 are connected.

[0092] The gas-solid separation zone 5 is provided with a first-stage second gas-solid separator 6 , and the second gas-solid separator 6 is a cyclone separator.

[0093] A solid outlet is provided on the lower side wall of the gas-solid separation zone 5 , and a lower outlet of the second gas-solid separator 6 extends to the solid outlet of the gas-solid separation zone 5 .

[0094] The device further comprises a fractionation unit 14, the gas outlet of the gas-solid separation zone 5 is connected to the inlet of the fractionation unit 14, and different outlets of the fractionation unit 14 respectively obtain coal tar and coal gas.

[0095] The solid outlet of the gas-solid separation zone 5 is connected to the lower inlet of the heat carrier heating unit through the heat carrier circulation pipe 7 .

[0096] The heat carrier heating unit comprises a heat carrier heater 8. A third gas-solid separator 9 is arranged in the heat carrier heating unit. The third gas-solid separator 9 is a cyclone separator.

[0097] A solid outlet is provided at the bottom of the heat carrier heating unit, and the solid outlet is connected to the inlet of the pyrolysis reaction zone 4 .

[0098] The device further comprises a smoke generator 10, on which a circulating gas inlet, an air inlet and a smoke outlet are arranged, and the smoke outlet is connected to the smoke inlet of the heat carrier heating unit.

[0099] The blast furnace injection separation unit comprises a blast furnace injection separator 11, and the blast furnace injection separator 11 comprises a two-stage cyclone separator; the outlet of the blast furnace injection separator 11 extracts powdered coke for blast furnace injection.

[0100] The device further comprises a fume recovery unit 13 , and the gas outlet of the blast furnace injection separator 11 is connected to the inlet of the fume recovery unit 13 .

[0101] Embodiment 3:

[0102] This embodiment provides a method for pyrolyzing raw coal to generate fine coke for blast furnace injection, the method is carried out using the device in Example 1, and comprises the following steps:

[0103] (1) washing and grinding raw coal, wherein the raw coal is lignite, and the washing includes screening and cyclone washing in sequence. The pulverized coal formed after the grinding is dried with argon at a temperature of 280°C, and the ash content of the obtained pulverized coal is 7%, and the proportion of particles with a particle size greater than 90 μm is 50%; the pulverized coal is mixed with circulating coal gas and enters a pyrolysis reaction zone for pyrolysis reaction, the mass volume ratio of pulverized coal to circulating coal gas is 2, the temperature of the circulating coal gas is 300°C, the temperature of the pyrolysis reaction is 550°C, the pressure is 0.4 MPaG, and the time is 2.5 s; the pyrolysis product is subjected to gas-solid separation to obtain solid powdered coke, and the gas-solid separation includes two cyclone separations. The gas phase product of the gas-solid separation is pyrolysis oil gas, which is fractionated to obtain coal tar and coal gas, and part of the coal gas is returned to step (1) for use as a gas heat carrier;

[0104] (2) The solid powdered coke obtained in step (1) is introduced into a heat carrier heater and heated by flue gas. The flue gas has a temperature of 900° C. and is generated by the combustion of fuel oil. Gas-solid separation is performed in the heat carrier heater. Part of the powdered coke leaves with the flue gas after heating. The proportion of this part of the powdered coke is 65%. The powdered coke is then separated by blast furnace injection. The blast furnace injection separation method includes cyclone separation and sintered metal filtration to obtain powdered coke and flue gas for blast furnace injection. The powdered coke for blast furnace injection is cooled and stored, and the flue gas is recovered and discharged. The powdered coke that does not leave with the flue gas is returned to step (1) as a solid heat carrier to be mixed with pulverized coal. The temperature of this part of the powdered coke is 700° C.

[0105] In this embodiment, the above method is used to pyrolyze low-rank coal. The powder coke obtained after blast furnace injection separation has a particle size greater than 90 μm accounting for 20%, and an ash content of 10%, which can meet the performance requirements of blast furnace injection materials. At the same time, the yield of coal tar generated is 18%, realizing the maximization of low-rank coal resource utilization.

[0106] Embodiment 4:

[0107] This embodiment provides a method for pyrolyzing raw coal to generate fine coke for blast furnace injection, the method is carried out using the device in Example 1, and comprises the following steps:

[0108] (1) washing and grinding the raw coal, wherein the raw coal is long flame coal, and the washing includes screening and cyclone washing in sequence. The pulverized coal formed after the grinding is dried with neon gas at a temperature of 320°C, and the ash content of the obtained pulverized coal is 6%, and the proportion of particles with a particle size greater than 90 μm is 30%; the pulverized coal is mixed with circulating coal gas and enters a pyrolysis reaction zone for pyrolysis reaction, the mass volume ratio of pulverized coal to circulating coal gas is 1.5, the temperature of the circulating coal gas is 250°C, the temperature of the pyrolysis reaction is 600°C, the pressure is 0.6 MPaG, and the time is 2s; the pyrolysis product is subjected to gas-solid separation to obtain solid powdered coke, and the gas-solid separation includes two cyclone separations. The gas phase product of the gas-solid separation is pyrolysis oil gas, which is fractionated to obtain coal tar and coal gas, and part of the coal gas is returned to step (1) for use as a gas heat carrier;

[0109] (2) The solid powdered coke obtained in step (1) is introduced into a heat carrier heater and heated by flue gas. The flue gas has a temperature of 950° C. and is generated by the combustion of fuel oil. Gas-solid separation is performed in the heat carrier heater. Part of the powdered coke leaves with the flue gas after heating. The proportion of this part of the powdered coke is 50%. The powdered coke is then separated by blast furnace injection. The blast furnace injection separation method includes cyclone separation and sintered metal filtration to obtain powdered coke and flue gas for blast furnace injection. The powdered coke for blast furnace injection is cooled and stored. The flue gas is recovered and discharged. The powdered coke that does not leave with the flue gas is returned to step (1) as a solid heat carrier to be mixed with pulverized coal. The temperature of this part of the powdered coke is 750° C.

[0110] In this embodiment, the above method is used to pyrolyze low-rank coal. The powder coke obtained after blast furnace injection separation has a particle size greater than 90 μm accounting for 23%, and an ash content of 11%, which can meet the performance requirements of blast furnace injection materials. At the same time, the yield of coal tar generated is 17.5%, realizing the maximization of low-rank coal resource utilization.

[0111] Embodiment 5:

[0112] This embodiment provides a method for pyrolyzing raw coal to generate fine coke for blast furnace injection, the method is carried out using the device in Example 2, and comprises the following steps:

[0113] (1) washing and grinding the raw coal, wherein the raw coal is non-sticky coal, and the washing includes screening and cyclone washing in sequence. The pulverized coal formed after the grinding is dried with nitrogen at a temperature of 200°C, and the ash content of the obtained pulverized coal is 5%, and the proportion of particles with a particle size greater than 90 μm is 45%; the pulverized coal is mixed with circulating coal gas and enters a pyrolysis reaction zone for pyrolysis reaction, the mass volume ratio of pulverized coal to circulating coal gas is 3, the temperature of the circulating coal gas is 350°C, the temperature of the pyrolysis reaction is 500°C, the pressure is 0.1 MPaG, and the time is 5s; the pyrolysis product is subjected to gas-solid separation to obtain solid powdered coke, and the gas-solid separation includes a primary cyclone separation. The gas phase product of the gas-solid separation is pyrolysis oil gas, which is fractionated to obtain coal tar and coal gas, and part of the coal gas is returned to step (1) for use as a gas heat carrier;

[0114] (2) The solid coke powder obtained in step (1) is introduced into a heat carrier heater and heated by flue gas. The flue gas has a temperature of 750° C. and is generated by the combustion of fuel oil. Gas-solid separation is performed in the heat carrier heater. Part of the coke powder leaves with the flue gas after heating. The proportion of this part of coke powder is 60%. The solid coke powder is then separated by blast furnace injection. The separation method of blast furnace injection is cyclone separation. Coke powder and flue gas for blast furnace injection are obtained. The coke powder for blast furnace injection is directly used for blast furnace smelting. The flue gas is recovered and discharged. The coke powder that does not leave with the flue gas is returned to step (1) as a solid heat carrier to be mixed with pulverized coal. The temperature of this part of coke powder is 640° C.

[0115] In this embodiment, the above method is used to pyrolyze low-rank coal. The proportion of particles with a particle size greater than 90 μm obtained after blast furnace injection separation is 18%, and the ash content is 9%, which can meet the performance requirements of blast furnace injection materials. At the same time, the yield of coal tar generated is 17.8%, realizing the maximization of low-rank coal resource utilization.

[0116] Comparative Example 1:

[0117] This comparative example provides a device and method for pyrolyzing raw coal to generate powdered coke for blast furnace injection. The device refers to the device in Example 1, with the only difference being that the washing device 1 is not included.

[0118] The method is similar to the method in Example 3, except that the washing operation in step (1) is not included.

[0119] In this comparative example, since the raw coal was not washed before pyrolysis, the ash content in the raw coal was relatively high. After pyrolysis and coke heating, the ash content reached 15%, which could not meet the requirements for blast furnace injection.

[0120] Comparative Example 2:

[0121] This comparative example provides a device and method for pyrolyzing raw coal to generate powdered coke for blast furnace injection. The device refers to the device in Example 1, with the only difference being that the heat carrier heating unit is a heat carrier combustion unit, that is, the heat carrier heater is adjusted to a heat carrier burner, a flue gas generator is not provided, and fuel and air are directly introduced into the heat carrier burner.

[0122] The method is similar to that in Example 3, except that in step (2), the solid coke powder is partially burned in the heat carrier burner to increase the temperature.

[0123] In this comparative example, since the raw coal is directly burned after the pyrolysis reaction to generate powdered coke, although the temperature can be increased as a heat carrier, the combustion will cause the ash content of the powdered coke to increase, which can reach 17% and cannot meet the use requirements of blast furnace injection materials.

[0124] From the above embodiments and comparative examples, it can be seen that the device of the utility model controls the particle size of the raw coal and reduces the ash content in the raw coal by setting up a washing and grinding device, and then heats the powdered coke instead of burning it after the pyrolysis reaction, thereby effectively reducing the ash content of the powdered coke, and then controls the particle size of the powdered coke through separation, so that the proportion of particles with a particle size greater than 90 μm for powdered coke injection in the blast furnace is no more than 25%, and the ash content is no more than 12%, which can meet the use requirements of blast furnace injection materials and effectively improve the utilization value of low-rank coal resources and powdered coke products; the method can generate coal tar and coal gas products while generating powdered coke for blast furnace injection, and the coal tar yield can reach more than 17%; the device has a simple structure, is easy to operate, has a low cost, high economic benefit, and a wide range of applications.

[0125] The applicant declares that the utility model uses the above embodiments to illustrate the detailed device of the utility model, but the utility model is not limited to the above detailed device, that is, it does not mean that the utility model must rely on the above detailed device to be implemented. The technicians in the relevant technical field should understand that any improvement to the utility model, the equivalent replacement of the device of the utility model, the addition of auxiliary devices, the selection of specific methods, etc., all fall within the protection scope and disclosure scope of the utility model.

Claims

1. A device for pyrolyzing raw coal to generate powdered coke for blast furnace injection, characterized in that: The device comprises a feeding unit, a pyrolysis and separation unit, a heat carrier heating unit and a blast furnace injection separation unit which are connected in sequence. The feeding unit comprises a washing device and a grinding device in sequence. The pyrolysis and separation unit is divided into a pyrolysis reaction zone and a gas-solid separation zone from bottom to top. The solid outlet of the gas-solid separation zone is connected to the inlet of the heat carrier heating unit. The lower part of the heat carrier heating unit is provided with a flue gas inlet. The upper outlet of the heat carrier heating unit is connected to the inlet of the blast furnace injection separation unit. The lower outlet of the blast furnace injection separation unit extracts powdered coke for blast furnace injection.

2. The device for pyrolyzing raw coal to generate powdered coke for blast furnace injection according to claim 1, characterized in that: The washing and selecting device comprises a screening device and a concentrating cyclone device in sequence. The screened material of the screening device enters the concentrating cyclone device, and the bottom outlet of the concentrating cyclone device is connected to the inlet of the grinding device.

3. The device for pyrolyzing raw coal to generate powdered coke for blast furnace injection according to claim 1, characterized in that: The pulverizing device comprises a coal mill, and protective gas is introduced into the pulverizing device for drying pulverized coal.

4. The device for pyrolyzing raw coal to generate powdered coke for blast furnace injection according to claim 3, characterized in that: The feeding unit further comprises a raw material tank, the outlet of the grinding device is connected to the inlet of the raw material tank, and the outlet of the raw material tank is connected to the inlet of the pyrolysis reaction zone; The raw material tank is provided with a first gas-solid separator, and the first gas-solid separator includes a cyclone separator and / or a bag filter; The feeding unit further comprises a circulating gas pipeline, which is connected to the inlet of the pyrolysis reaction zone after merging with the outlet pipeline of the raw material tank.

5. The device for pyrolyzing raw coal to generate powdered coke for blast furnace injection according to claim 1, characterized in that: The pyrolysis and separation unit comprises an empty barrel reactor, the lower part of the empty barrel reactor is a pyrolysis reaction zone, the upper part is a gas-solid separation zone, and the pyrolysis reaction zone and the gas-solid separation zone are connected; At least one second gas-solid separator is provided in the gas-solid separation zone, and the second gas-solid separator includes a cyclone separator; A solid outlet is provided on the lower side wall of the gas-solid separation zone, and the lower outlet of the second gas-solid separator extends to the solid outlet of the gas-solid separation zone.

6. The device for pyrolyzing raw coal to generate powdered coke for blast furnace injection according to claim 5, characterized in that: The device also includes a fractionation unit, the gas outlet of the gas-solid separation zone is connected to the inlet of the fractionation unit, and different outlets of the fractionation unit respectively obtain coal tar and coal gas.

7. The device for pyrolyzing raw coal to generate powdered coke for blast furnace injection according to claim 1, characterized in that: The solid outlet of the gas-solid separation zone is connected to the lower inlet of the heat carrier heating unit via a heat carrier circulation pipe; The heat carrier heating unit includes a heat carrier heater, and a third gas-solid separator is provided in the heat carrier heating unit, and the third gas-solid separator includes a cyclone separator; A solid outlet is provided at the bottom of the heat carrier heating unit, and the solid outlet is connected to the inlet of the pyrolysis reaction zone.

8. The device for pyrolyzing raw coal to generate powdered coke for blast furnace injection according to claim 1, characterized in that: The device also includes a smoke generator, which is provided with a fuel oil inlet or a circulating gas inlet, an air inlet and a smoke outlet, and the smoke outlet is connected to the smoke inlet of the heat carrier heating unit.

9. The device for pyrolyzing raw coal to generate powdered coke for blast furnace injection according to claim 1, characterized in that: The blast furnace injection separation unit comprises a blast furnace injection separator, and the outlet of the blast furnace injection separator extracts the powdered coke for blast furnace injection; The blast furnace injection separator includes a cyclone separator and / or a precision filter, and the precision filter includes a sintered metal filter.

10. The device for pyrolyzing raw coal to generate fine coke for blast furnace injection according to claim 9, characterized in that: The device also includes a fume recovery unit, and the gas outlet of the blast furnace blowing separator is connected to the inlet of the fume recovery unit.

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