A system and method for preparing solid fuel for cement clinker production

Abstract

The present invention discloses a preparation system and method for solid fuel for cement clinker production, and belongs to the technical field of fuel preparation in cement clinker. In view of the problem that gasified fly ash, a byproduct of existing coal gasification, is difficult to utilize and the cost of preparing the fuel required for cement clinker is high, the present invention provides a preparation system for solid fuel for cement clinker production, which includes a raw coal feeding device, which is connected to a coal grinding device, and the outlet of the coal grinding device is connected to the inlet of a fuel conveying device through a separation device, and also includes a gasified fly ash feeding device, which is connected to the fuel conveying device through a separation device. The present invention mixes gasified fly ash with coal and pulverizes it as rotary kiln fuel, which solves the problem that gasified fly ash is difficult to utilize, reduces the coal consumption in cement clinker production, and reduces the operating cost of cement production enterprises. The entire system has a simple structure and is easy to build; at the same time, the preparation method provided by the present invention is simple to operate and easy to implement.

Description

Technical Field

[0001] The present invention belongs to the technical field of fuel preparation in cement clinker, and more specifically, relates to a system and method for preparing solid fuel for cement clinker production. Background Art

[0002] Coal gasification is one of the main technologies for clean and efficient utilization of coal. Fluidized bed gasification technology has become one of the more advanced coal gasification technologies due to its advantages such as uniform bed temperature, high heat and mass transfer performance, high gasification intensity, strong adaptability to coal types, and no tar and phenolic compounds in the product coal gas. However, while producing coal gas, fluidized bed gasification technology will produce a large amount of gasification fly ash with high carbon content and fine particle size in the process. The output of gasification fly ash is about 20% of the mass of the original coal. The large amount of accumulated gasification fly ash is not only easy to cause dust pollution, but also will cause a huge waste of carbon resources. One of the main ways to utilize gasification fly ash is to use a pneumatic conveying pipeline to directly pass it into a fluidized bed boiler for mixed combustion as fuel. However, compared with the particle size of coal powder entering the fluidized bed boiler (0-10mm), the particle size of gasification fly ash (0-90um) is smaller, and the gasification fly ash is easily carried out of the furnace by the higher fluidizing gas and enters the subsequent flue system, where it burns, causing the flue system to overheat and affect the operation of the subsequent flue gas purification equipment. At the same time, the increase in the content of particulate matter in the flue gas will also accelerate the wear of the equipment and affect safe production. In addition, the volatile content of gasification fly ash is extremely low, and it cannot be completely burned in a fluidized bed boiler at 800℃-1000℃, which still wastes carbon resources.

[0003] The preparation method of cement clinker in my country mainly adopts the new dry process cement rotary kiln production process. The fineness of the fuel coal powder used in the rotary kiln is generally 80um, and the square hole sieve residue is 12%. In the cement clinker production process, the stability of the fuel properties is required to be high during the operation of the rotary kiln. The change of fuel properties will lead to the change of the flame length and temperature distribution in the rotary kiln, affecting the quality of the clinker and the stability of the kiln skin. Therefore, in the cement clinker industry, the solid fuel of the rotary kiln is mostly a single coal type or a uniform coal blending method before grinding, and less secondary addition of other solid powdered fuels. The process of adding powder to the coal grinding system to prepare powdered fuel has been applied in the metallurgical industry. The commonly used process of adding powder is as follows: the external powder enters the powder bin, and the external powder is fed into the weighing belt or feeding device in front of the coal mill by the weighing feeding system at the bottom of the powder bin. The external powder and the raw coal enter the coal mill together for grinding and pulverization. However, this process has the following problems: In order to prevent the secondary pollution of dust generated when the external powder is mixed with the raw coal, water needs to be sprayed in the feeding system of the external powder, which will increase the complexity of the feeding system equipment of the external powder, and the subsequent In the coal pulverizing process, more hot flue gas is needed to dry the moisture of the external powder, which will lead to an increase in the energy consumption of the coal pulverizing system; the external powder does not need to be ground because of its small particle size, and the external powder is repeatedly ground in the coal pulverizer, wasting electricity; at the same time, the presence of external powder will also reduce the grindability of the raw coal and increase the internal wear of the coal pulverizer, affecting the grinding quality of the raw coal and reducing the life of the coal pulverizer; for the coal pulverizing system of the built cement plant, if it is necessary to modify and add a secondary powder adding device, the coal pulverizing system area space is very likely to be insufficient to place the huge powder silo. Because the particle size distribution of the fuel coal powder used in the rotary kiln in the preparation of cement clinker is relatively close to the particle size distribution of gasified fly ash, and the combustion temperature of the rotary kiln head can be as high as 1800℃, the gasified fly ash can be completely burned, so the gasified fly ash can be used as a raw material to participate in the preparation of cement clinker, but how to ensure that the rotary kiln can work stably when adding gasified fly ash as a secondary powdered fuel, and how to save costs at the same time is an urgent problem that technicians in this field need to solve.

[0004] Corresponding improvements have also been made to the above problems, such as China Patent Application No. CN201110299318.0, published on January 25, 2012. The patent discloses a method and device for feeding a mill, which belongs to the technical field of feeding a mill in a blast furnace coal injection system during blast furnace ironmaking. The method is to add powdery and granular materials into a spray tank, first transport the powdery and granular materials to the position of the silo, then load the materials into the silo, and the materials enter the spray tank from the silo, and then use gas in the spray tank to spray the powdery and granular materials into the mill through a pipeline; the device includes a silo, a charging pipe, a spray system, a powder conveying pipeline, etc. The disadvantage of this patent is that the external powder is input into the mill by pneumatic conveying, and a large amount of pressurized conveying gas enters the mill, which destroys the uniformity of the raw material distribution inside the mill and affects the working efficiency of the mill. At the same time, if air is used for conveying, the oxygen content inside the mill will increase, causing safety hazards and being difficult to control the oxygen concentration. In addition, the powder particles in the pneumatic conveying will seriously erode the internal structure of the mill and affect the life of the mill. Summary of the invention

[0005] 1. Problems to be solved

[0006] In view of the problem that the existing coal gasification byproduct gasification fly ash is difficult to utilize and the cost of preparing the fuel required for cement clinker is high, the present invention provides a preparation system and method for solid fuel for cement clinker production. The present invention mixes gasification fly ash with coal and prepares powder as the fuel required for cement clinker production, which solves the problem that gasification fly ash is difficult to utilize, reduces the coal consumption of cement clinker production, and reduces the operating cost of cement production enterprises. The whole system structure is simple and easy to build; at the same time, the preparation method provided by the present invention is simple to operate and easy to implement. There is no dust leakage in the whole process, which avoids environmental pollution.

[0007] 2. Technical solution

[0008] To solve the above problems, the present invention adopts the following technical solutions.

[0009] A preparation system for solid fuel for cement clinker production includes a raw coal feeding device, the raw coal feeding device is connected to a coal grinding device, the outlet of the coal grinding device is connected to an inlet of a fuel conveying device through a separation device, and also includes a gasification fly ash feeding device, the gasification fly ash feeding device is connected to the fuel conveying device through a separation device. Each device works independently and does not interfere with each other, thereby improving the stability of the entire process, and utilizing the byproducts generated by coal gasification, with high economic benefits.

[0010] Furthermore, the gasification fly ash feeding device includes a gasification fly ash bin, which is connected to the inlet of the fly ash intermediate bin through a bin pump, the outlet of the fly ash intermediate bin is connected to a screw feeder, and the screw feeder is connected to the separation device through a pipeline. The entire gasification fly ash feeding device has high sealing performance, and there is no leakage during the gasification fly ash transportation process.

[0011] Furthermore, a variable frequency star feeder is provided between the screw feeder and the pipeline, so that the feeding of the gasified fly ash is uniform and stable, and is convenient for full mixing with the coal powder from the ball mill.

[0012] Furthermore, a material collector is provided on the top of the gasification fly ash bin, and the material collector is connected to the pressure relief pipe in the bin pump, so as to reduce the dust stirred up by the gas in the gasification fly ash bin when the gasification fly ash enters the gasification fly ash bin.

[0013] Furthermore, the separation device includes a cyclone separator, a bag dust collector connected to the cyclone separator, the cyclone separator is connected to the coal grinding device, and the bag dust collector is connected to the fuel conveying device. The coal powder ground by the ball mill is screened for particle size and the gasified fly ash and coal powder are fully mixed, so that the mixture meets the fuel requirements for cement clinker production.

[0014] Furthermore, a separation outlet is provided at the bottom of the cyclone separator, and the separation outlet is connected to the inlet of the coal grinding device through a screw conveyor. Large particles in the mixture enter the ball mill from the separation outlet for further grinding, so that the materials are recycled and the cost is saved.

[0015] Furthermore, the coal grinding device is a ball mill, and a hot air inlet is arranged at the inlet of the ball mill. The structure is simple, the grinding effect is uniform and the efficiency is high.

[0016] Furthermore, the fuel delivery device includes a powder bin, a discharger, a powder intermediate bin and a disc feeder which are arranged in sequence, the powder bin is connected to the separation device, and the disc feeder is connected to the component requiring fuel. The entire fuel delivery device has a strong sealing performance to prevent material leakage.

[0017] Furthermore, the mass ratio of gasification fly ash to raw coal is (0.05-0.4): 1, so that it can meet the requirements as a fuel while improving the economic utilization rate.

[0018] A method for preparing a solid fuel preparation system for cement clinker production as described in any one of the above items comprises the following steps:

[0019] S1: The raw coal enters the coal grinding device through the raw coal feeding device to be ground into coal powder, and the coal powder enters the separation device;

[0020] S2: The gasified fly ash enters the separation device through the gasified fly ash feeding device, and the gasified fly ash and the coal powder are fully mixed;

[0021] S3: The mixed material is separated by a separation device to remove large particles in the mixed material. The particle size of the separated mixed material meets the solid fuel requirements for cement clinker production;

[0022] S4: The separated mixed material is transported through the fuel conveying device to the place where the fuel is needed for producing cement clinker.

[0023] 3. Beneficial effects

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The present invention uses the gasification fly ash and coal as rotary kiln fuel, which can effectively utilize the gasification fly ash resource, effectively solve the problem that the byproduct gasification fly ash in the coal gasification field is difficult to utilize, and realize the effective utilization of carbon resources. At the same time, it reduces the coal consumption of cement clinker production and reduces the operating cost of cement production enterprises; and the mixture of gasification fly ash and raw coal is separated by a separation device, so that the mixture of gasification fly ash and raw coal meets the solid fuel requirements for cement clinker production. The entire solid fuel preparation system has a simple structure, is easy to maintain, and has a low overall manufacturing cost;

[0026] (2) The gasified fly ash produced by coal gasification of the present invention enters the fly ash intermediate bin through the gasified fly ash bin and bin pump, and then enters the separation device from the fly ash intermediate bin through the screw feeder. There is no dust leakage in the entire transportation process, the sealing performance is high, and no secondary dust pollution is caused. Water spraying treatment is avoided during the transportation of the gasified fly ash, thereby saving water resources. At the same time, the gasified fly ash is directly transported to the separation device, so that the gasified fly ash does not need to be repeatedly ground in the coal grinding device to waste electric energy, thereby saving energy consumption, and also avoiding the reduction of the grindability of the raw coal due to the presence of the gasified fly ash, reducing the wear inside the coal grinding device, and increasing the service life of the coal grinding device.

[0027] (3) The gasified fly ash of the present invention enters the separation device through the cooperation of the spiral feeder and the variable frequency star feeder, so that the amount of gasified fly ash entering the pipeline is stable and accurate, so that the gasified fly ash and the coal powder are fully mixed in the pipeline, ensuring the stability of the properties of the mixed material; at the same time, a collector is provided on the top of the gasified fly ash bin, which is conducive to reducing the dust stirred up by the gas in the bin when the gasified fly ash enters the gasified fly ash bin;

[0028] (4) The separation device of the present invention includes a cyclone separator and a bag filter. The cyclone separator separates large particles from the mixture of coal powder and gasified fly ash. The separated mixture enters the bag filter for further collection. The gasified fly ash and coal powder are fully mixed in the separation device so that the mixture has high uniformity and stability, which can meet the requirements of solid fuel for cement clinker production. At the same time, a separation outlet is provided at the bottom of the cyclone separator. The separated large particles enter the coal grinding device through the separation outlet for coal grinding, thereby ensuring the recycling of large particles, effectively saving energy and reducing costs.

[0029] (5) The present invention uses a ball mill as a coal grinding device. The ball mill has a simple structure, good coal grinding effect and high efficiency. At the same time, a hot air inlet is arranged at the entrance of the ball mill to further ensure the grinding effect of the raw coal. The mixed material is fed into the disc feeder by a double buffer feeding component composed of a discharger and a powder intermediate bin. The mixed powder is then stably fed into a rotary kiln or a decomposition furnace for cement clinker production by the disc feeder with stable and excellent conveying performance. The whole process is free of dust leakage and has high sealing performance.

[0030] (6) The present invention can place the gasification fly ash bin and bin pump, which occupy a large area, at the periphery of the coal grinding system, i.e., the area composed of the raw coal feeding device and the coal grinding device. The gasification fly ash is pneumatically transported by the bin pump from the long-distance gasification fly ash bin to the fly ash intermediate bin inside the coal grinding system area, thereby effectively solving the problem of insufficient space in the coal grinding system area when an existing cement plant is renovated and equipped with a powder adding device. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the present invention.

[0032] In the figure: 1. Dust collector on the top of the silo; 2. Raw coal silo; 3. Weighing belt conveyor; 4. Gasification fly ash silo; 41. Aggregator; 5. Silo pump; 6. Fly ash intermediate silo; 7. Screw feeder; 8. Variable frequency star feeder; 9. Ball mill; 10. Cyclone separator; 11. Bag dust collector; 12. Powder silo; 13. Discharger; 14. Powder intermediate silo; 15. Disc feeder; 16. Screw conveyor; 17. Draft fan. DETAILED DESCRIPTION

[0033] The present invention is further described below in conjunction with specific embodiments and drawings.

[0034] Example 1

[0035] like Figure 1As shown, a preparation system for solid fuel for cement clinker production includes a raw coal feeding device, which conveys raw coal to a coal grinding device; the raw coal feeding device is connected to the coal grinding device, and the coal grinding device grinds the raw coal into coal powder; the outlet of the coal grinding device is connected to the inlet of the fuel conveying device through a separation device, and the preparation system also includes a gasification fly ash feeding device, which is connected to the fuel conveying device through a separation device, and the raw coal and gasification fly ash are fully mixed and separated in the separation device to obtain a mixture that meets the fuel standard required for cement clinker production, and then transported to a rotary kiln or a decomposition furnace and other places where fuel is required through the fuel conveying device. The system uses gasification fly ash and coal to mix and pulverize as the fuel required for cement clinker production, which can effectively utilize the resource of gasification fly ash, effectively solves the problem that the byproduct gasification fly ash in the field of coal gasification is difficult to utilize, realizes the effective utilization of carbon resources, and at the same time reduces the coal consumption of cement clinker production, reduces the operating cost of cement production enterprises, and the entire system has a simple structure, is easy to build, and does not affect each other's work, and has a high prospect of use.

[0036] The following is a detailed structural introduction to the preparation system of solid fuel for cement clinker production. In this embodiment, the coal grinding device uses a ball mill 9, which has a simple structure, high coal grinding efficiency and uniform coal grinding; the raw coal feeding device includes a raw coal bin 2, and the raw coal bin 2 is connected to a weighing belt conveyor 3, and the weighing belt conveyor 3 is connected to the inlet of the ball mill 9 to avoid leakage of raw coal during transportation and ensure a pollution-free working environment; the raw coal is stored in the raw coal bin 2, and the raw coal is quantitatively transported to the ball mill 9 through the weighing belt conveyor 3. The quantitative transportation of raw coal ensures the stable operation of the ball mill 9 and uniform coal grinding; the separation device includes a cyclone separator 10, a bag dust collector 11 connected to the cyclone separator 10, the cyclone separator 10 is connected to the outlet of the ball mill 9 through a pipeline, the bag dust collector 11 is connected to the fuel conveying device, and the coal powder enters the Large particles are separated in the cyclone separator 10 and then enter the bag filter 11 for further collection. After two-stage separation, the mixture has higher stability and the particle size of the mixture can meet the requirements of solid fuel for cement clinker production. The fuel conveying device in this system includes a powder bin 12, a discharger 13, a powder intermediate bin 14 and a disc feeder 15 arranged in sequence. The powder bin 12 is connected to the separation device, and the disc feeder 15 is connected to the components requiring fuel such as a rotary kiln or a decomposition furnace. The double buffer feeding component of the discharger 13 and the powder intermediate bin 14 is used to input the mixed material into the disc feeder 15, and then the disc feeder 15 with stable and excellent conveying performance stably feeds the mixed powder into the rotary kiln or decomposition furnace used for cement clinker production. The whole process does not leak dust and has high sealing performance.

[0037] At the same time, the gasification fly ash feeding device of the system includes a gasification fly ash bin 4, which is connected to the inlet of the fly ash intermediate bin 6 through a bin pump 5, and the outlet of the fly ash intermediate bin 6 is connected to the screw feeder 7, and the screw feeder 7 is connected to the cyclone separator 10 through a pipeline. The gasification fly ash is directly transported to the cyclone separator 10 through the screw feeder 7. There is no dust leakage in the entire transportation process, the sealing performance is high, and secondary dust pollution will not be caused, and water spraying treatment during the transportation of the gasification fly ash is avoided, thereby saving water resources; at the same time, the gasification fly ash does not need to be repeatedly ground in the ball mill 9, which wastes electric energy, thereby saving energy consumption, and also avoids the raw coal from reducing its own grindability due to the presence of gasification fly ash, reduces the wear inside the ball mill 9, and increases the service life of the ball mill 9; and the present invention adopts a two-stage ash bin of the gasification fly ash bin 4 plus the fly ash intermediate bin 6 to store the gasification fly ash, ensuring that the gasification fly ash will not form bridges due to gravity extrusion and agglomeration, thereby avoiding fluctuations during subsequent gasification fly ash transportation. The gasified fly ash and coal powder in the present invention are fully mixed in the pipeline leading to the cyclone separator 10, which ensures the stability of the properties of the mixed material. The fully mixed mixed material is separated into large particles in the cyclone separator 10, and then enters the bag dust collector 11 for further dust removal. The obtained mixed material can be used as the fuel required for cement clinker production. The bag dust collector 11 is connected to the induced draft fan 17, and the induced draft fan 17 plays the role of induced draft and exhaust, so that the entire system is in negative pressure vacuum operation, so that the gasified fly ash and the solid particles from the ball mill 9 flow along the pipeline to the cyclone separator 10 to the bag dust collector 11; secondly, when the system between the ball mill 9 and the bag dust collector 11 is in negative pressure vacuum operation, there will be no dust particles leaking to pollute the environment. Of course, the raw coal feeding device, coal grinding device, separation device, fuel conveying device and gasified fly ash feeding device described in the present invention are not limited to the structures listed in this embodiment, and other existing devices that can achieve the same function can also be used in the present invention.

[0038] The solid fuel preparation system for cement clinker production described in the present invention can place the gasification fly ash bin 4 and the bin pump 5, which occupy a relatively large area, on the periphery of the coal grinding system, i.e., the area composed of the raw coal feeding device and the coal grinding device. The gasification fly ash is pneumatically transported by the bin pump 5 from the long-distance gasification fly ash bin 4 to the fly ash intermediate bin 6 inside the coal grinding system area, which effectively solves the problem of insufficient space in the coal grinding system area when an existing cement plant is renovated to add a powder adding device, and is easy to renovate.

[0039] A method for preparing a solid fuel preparation system for cement clinker production as described above, the steps are as follows:

[0040] S1: Raw coal is bituminous coal in this embodiment. The industrial analysis of bituminous coal is shown in Table 1. The bituminous coal enters the weighing belt conveyor 3 from the bottom outlet of the raw coal bin 2, and is quantitatively input into the inlet of the ball mill 9 after being weighed by the weighing belt conveyor 3. The bituminous coal flow rate is 24t / h. The coal powder ground by the ball mill 9 enters the cyclone separator 10 through a pipeline;

[0041] S2: The particle size distribution of gasified fly ash from the fluidized bed coal gasification process is D90=76.83um, which meets the fuel particle size requirements of the rotary kiln. The gasified fly ash is transported from the gas station to the vicinity of the gasified fly ash bin 4 by a tank truck, and the gasified fly ash is transported from the tank truck to the gasified fly ash bin 4 by pneumatic conveying. The gasified fly ash enters the bin pump 5 from the bottom outlet of the gasified fly ash bin 4, and is transported to the fly ash intermediate bin 6 by the pneumatic conveying method of the bin pump 5. The gasified fly ash then enters the screw feeder 7 from the bottom outlet of the fly ash intermediate bin 6, and the gasified fly ash is quantitatively conveyed by the screw feeder 7 The fly ash is mixed with the pulverized coal from the ball mill 9 in the pipeline to the outlet of the ball mill 9. In this embodiment, the mass ratio of gasified fly ash to raw coal is (0-0.4): 1. Compared with the coal used as fuel for cement clinker production, the fly ash is more difficult to burn. When the mass ratio of the fly ash to the raw coal is high, the mixed fuel prepared is difficult to use and cannot meet the fuel requirements for cement clinker. When the mass ratio is low, it has no economic value. The industrial analysis of the fly ash is shown in Table 1. The flow rate of the fly ash is 6 t / h. The volatile matter of the mixed powder is greater than 20%, which meets the fuel requirements of the rotary kiln:

[0042] Table 1 Industrial analysis of coal and gasification fly ash

[0043] Fuel Type Mad Aad Vad FCad bituminous coal 6.64 9.15 35.47 48.74 Gasification fly ash 0.31 15.70 0.00 83.99

[0044] S3: The mixed powder of gasified fly ash and coal powder is separated into large particles in the cyclone separator 10, and the large particles in the mixed material are screened out. The mixed powder of gasified fly ash and coal powder fully mixed in the cyclone separator 10 enters the bag filter 11. The particle size of the separated mixed material meets the solid fuel requirement for cement clinker production;

[0045] S4: The mixed powder enters the fuel conveying device composed of a powder bin 12, a discharger 13, a powder intermediate bin 14 and a disc feeder 15 connected in sequence from the bottom outlet of the bag filter 11. The mixed powder is conveyed by the fuel conveying device to the rotary kiln or the decomposition furnace for combustion. In order to improve work efficiency, two groups of fuel conveying devices are set up, and the two groups of fuel conveying devices are respectively sent to different places.

[0046] The preparation method is simple to operate and easy to implement. During the whole process, no dust will be leaked, thus avoiding environmental pollution and having strong overall sealing performance.

[0047] Example 2

[0048] Basically the same as Example 1, in this embodiment, a variable frequency star feeder 8 is further provided between the screw feeder 7 and the pipeline, and the gasified fly ash is quantitatively transported to the variable frequency star feeder 8 through the screw feeder 7, and then is quantitatively transported to the pipeline passing through the cyclone separator 10 through the secondary quantitative transport of the variable frequency star feeder 8, so that the amount of gasified fly ash entering the pipeline is stable and accurate, which is convenient for sufficient mixing with coal powder. Furthermore, a collector 41 is provided on the top of the gasification fly ash bin 4, and the gasification fly ash produced by coal gasification enters the gasification fly ash bin 4 through the collector 41, thereby ensuring the sealing performance of the process of the gasification fly ash entering the gasification fly ash bin 4, avoiding the leakage of the gasification fly ash to cause environmental pollution and waste, and at the same time reducing the dust stirred up by the gas in the bin when the gasification fly ash enters the gasification fly ash bin 4; the collector 41 is connected to the pressure relief pipe in the bin pump 5, and the pressure relief pipe is used to perform pressure relief operation on the bin pump 5. When the pressure is relieved, the pressure relief pipe contains gasification fly ash, which cannot be directly discharged and emptied, and therefore it is connected to the collector 41, so that the gasification fly ash after pressure relief enters the gasification fly ash bin 4, and the gasification fly ash is recycled. At the same time, a silo top dust collector 1 is arranged on the top of the raw coal silo 2, the gasification fly ash silo 4 and the fly ash intermediate silo 6. The silo top dust collector 1 recycles the dust mixed in the raw coal or gasification fly ash to ensure the purity of the raw coal and gasification fly ash, laying the foundation for the subsequent preparation of fuel; on the other hand, since a collector 41 is arranged on the top of the gasification fly ash silo 4, the collector 41 can reduce the load of the silo top dust collector 1 and increase the service life of the silo top dust collector 1.

[0049] At the same time, a separation outlet is provided at the bottom of the cyclone separator 10, and the separation outlet is provided on the side of the bottom of the cyclone separator 10. The separation outlet is used for processing large-particle materials in the mixture. The separation outlet is connected to the inlet of the coal grinding device through a screw conveyor 16. The mixture is separated into large-particle coal powder in the cyclone separator 10. The separated large-particle coal powder enters the screw conveyor 16 from the separation outlet. The large-particle coal powder is transported to the inlet of the ball mill 9 by the screw conveyor 16, and enters the ball mill 9 again for grinding, thereby ensuring the recycling of large-particle materials, effectively saving energy, and reducing costs. More specifically, in this embodiment, a hot air inlet is provided at the inlet of the ball mill 9. The hot air comes from a hot air furnace or a rotary kiln head cooler. The addition of hot air further ensures the grinding effect of the raw coal.

[0050] The examples described in the present invention are merely descriptions of the preferred implementation modes of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made to the technical solutions of the present invention by engineers and technicians in this field should all fall within the protection scope of the present invention.

Claims

1. A system for preparing solid fuel for cement clinker production, comprising a raw coal feeding device, the raw coal feeding device is connected to a coal grinding device, the outlet of the coal grinding device is connected to the inlet of a fuel conveying device through a separation device, and is characterized in that: The invention also comprises a gasification fly ash feeding device, which is connected to the fuel conveying device via a separation device; the gasification fly ash feeding device comprises a gasification fly ash bin (4), which is connected to the inlet of a fly ash intermediate bin (6) via a bin pump (5), the outlet of the fly ash intermediate bin (6) is connected to a screw feeder (7), and the screw feeder (7) is connected to the separation device via a pipeline; a variable frequency star feeder (8) is also provided between the screw feeder (7) and the pipeline; the gasification fly ash bin A material collector (41) is provided at the top of (4), and the material collector (41) is connected to the pressure relief pipe in the silo pump (5); the separation device comprises a cyclone separator (10), a bag dust collector (11) connected to the cyclone separator (10), the cyclone separator (10) is connected to the coal grinding device, and the bag dust collector (11) is connected to the fuel conveying device; a separation outlet is provided at the bottom of the cyclone separator (10), and the separation outlet is connected to the inlet of the coal grinding device through a screw conveyor (16); The coal grinding device is a ball mill (9), and a hot air inlet is provided at the inlet of the ball mill (9); The fuel conveying device comprises a powder bin (12), a discharger (13), a powder intermediate bin (14) and a disc feeder (15) which are arranged in sequence, the powder bin (12) being connected to the separation device, and the disc feeder (15) being connected to a component requiring fuel; The mass ratio of gasification fly ash to raw coal is (0.05-0.4):1; The gasification fly ash refers to the gasification fly ash from the fluidized bed coal gasification process.

2. A method for preparing a solid fuel preparation system for cement clinker production according to claim 1, characterized in that: The following steps are involved: S1: The raw coal enters the coal grinding device through the raw coal feeding device to be ground into coal powder, and the coal powder enters the separation device; S2: The gasified fly ash enters the separation device through the gasified fly ash feeding device, and the gasified fly ash and the coal powder are fully mixed; S3: The mixed material is separated by a separation device to remove large particles in the mixed material. The particle size of the separated mixed material meets the solid fuel requirements for cement clinker production; S4: The separated mixed material is transported through the fuel conveying device to the place where the fuel is needed for producing cement clinker.

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