Coal combustion system of cement production line

Abstract

The utility model provides a coal combustion system for a cement production line, which comprises at least two raw coal storage bins for storing raw coal with different qualities, a conveying device arranged below the raw coal storage bins, a coal grinding device arranged at one end of the conveying device far away from the raw coal storage bins and comprising a hot air inlet and a pulverized coal outlet, the pulverized coal outlet is communicated with a bag dust collector through a first pulverized coal pipeline, an air exhaust windmill is arranged on one side of the bag dust collector and used for exhausting air in the bag dust collector, pulverized coal storage bins corresponding to the raw coal storage bins are arranged at the bottom of the bag dust collector, and a second pulverized coal pipeline is correspondingly arranged at the bottom of each pulverized coal storage bin. According to the coal powder conveying device, through different conveying paths, raw coal of different qualities is ground and then conveyed into the corresponding combustors to be combusted, the efficiency is high, and the coal cost is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of cement production, in particular to a coal combustion system for a cement production line. Background Art

[0002] Cement is a powdery hydraulic inorganic binder. After being stirred with water, it becomes a slurry, which can harden in the air or harden better in water, and can firmly cement materials such as sand and stone together. The concrete made by cementing crushed stones has not only high strength after hardening, but also can resist the erosion of fresh water or salt water.

[0003] Coal accounts for 40-50% of the cement production cost. Reducing the coal cost is an important issue in the cement production process. There are multiple coal injection points in the cement kiln calcination process, which are coal injection at the kiln head and coal injection into the decomposition furnace respectively. The coal injection at the kiln head and the coal injection into the decomposition furnace account for about 40% and 60% respectively. The heat generated by the coal combustion at the kiln head promotes the sintering of the clinker, and the temperature requirement reaches about 1450°C. High-temperature calcination can improve the quality of the clinker; the heat generated by the coal injection into the decomposition furnace is mainly used for raw material deacidification, and the temperature is about 850-900°C.

[0004] At present, the coal injection combustion on the cement production line mainly burns by adding ground coal powder into the corresponding burner, with low efficiency and no distinction between the coal powder of different burners, resulting in high costs. Summary of the Utility Model

[0005] Based on this, the purpose of the utility model is to provide a coal combustion system for a cement production line to solve the problems existing in the prior art.

[0006] The utility model provides a coal combustion system for a cement production line, including: a raw coal storage device, the raw coal storage device includes at least two raw coal storage bins, the raw coal storage bins are used for storing raw coal of different qualities, a transportation device is arranged below the raw coal storage bins, a coal grinding device is arranged at one end of the transportation device far away from the raw coal storage bins, the coal grinding device is used for grinding raw coal of different qualities, the coal grinding device includes a hot gas inlet and a coal powder outlet, the coal powder outlet is communicated with a bag filter through a first coal powder pipeline, an air extraction fan is arranged on one side of the bag filter, the air extraction fan is used for extracting the air in the bag filter, so that the inside of the bag filter is in negative pressure and the ground coal powder is collected by negative pressure, a coal powder storage bin corresponding to the raw coal storage bin is arranged at the bottom of the bag filter, and a second coal powder pipeline is correspondingly arranged at the bottom of each coal powder storage bin to convey the coal powder in the coal powder storage bin to the corresponding burner for combustion.

[0007] Preferably, the combustion system includes two raw coal storage bins and two pulverized coal storage bins. Two different types of raw coal with different calorific values are stored in the two raw coal storage bins respectively, and two different types of pulverized coal with different calorific values are correspondingly stored in the two pulverized coal storage bins. The burner includes a kiln head burner and a decomposition furnace burner. The calorific value of the pulverized coal in the pulverized coal storage bin connected to the kiln head burner is higher than that of the pulverized coal in the pulverized coal storage bin connected to the decomposition furnace burner.

[0008] Preferably, a kiln head pulverized coal meter is provided between the kiln head burner and the corresponding pulverized coal storage bin, and a decomposition furnace pulverized coal meter is provided between the decomposition furnace burner and the corresponding pulverized coal storage bin.

[0009] Preferably, the thrust of the kiln head burner is greater than that of the decomposition furnace burner.

[0010] Preferably, the raw coal storage device is a conical storage barrel, and a baffle is provided in the conical storage barrel. The inner cavity of the conical storage barrel is partitioned into two storage cavities by the baffle to form the two raw coal storage bins.

[0011] Preferably, a plurality of dust collection bags are provided in the bag filter, and the dust collection bags are used to filter and collect the pulverized coal ground by the coal grinding device.

[0012] Preferably, an explosion-proof gate is provided on the first pulverized coal pipeline.

[0013] Preferably, the combustion system further includes a CO 2 storage system. The CO 2 storage system is communicated with the bag filter and the coal grinding device respectively through a gas pipeline.

[0014] The beneficial effects of the present invention are as follows: The coal combustion system of the cement production line provided by the present invention includes a plurality of raw coal storage bins for storing raw coal of different qualities. Through the transportation device, the grinding device, the bag filter, and the pulverized coal storage bin, the raw coal of different qualities is ground and then transported to different pulverized coal storage bins, and then burned through different burners. Through different paths, the pulverized coal with high calorific value is transported to the kiln head for coal injection combustion, and the pulverized coal with low calorific value is transported to the decomposition furnace for coal injection combustion, so as to burn the coal of different qualities specifically, which not only ensures the combustion efficiency of different burners, but also reduces the use of high-quality coal, thus reducing the cost. Further, different raw coals are transported to the coal grinding device for grinding through the transportation device respectively, and the pulverized coal after different grindings is collected by means of a negative pressure extraction by an air extraction fan, and different pulverized coals are transported to the corresponding burners as required. The working efficiency is high. Only the number of storage bins is increased, while the transportation device, the grinding device, and the bag filter can be shared, so that the transportation of pulverized coal in different paths can be realized, and the investment and transformation cost can be reduced, which is suitable for large-scale promotion.

[0015] Additional aspects and advantages of the present utility model will be given in part in the following description, become apparent in part from the following description, or be understood through the practice of the present utility model. Brief Description of the Drawings

[0016] Figure 1 Structural schematic diagram of the coal combustion system for the cement production line provided by the present utility model;

[0017] Figure 2 is Figure 1 A structural schematic diagram of the raw coal storage device;

[0018] Figure 3 is Figure 2 A structural schematic diagram from another perspective.

[0019] Description of the main component symbols:

[0020] 10. Raw coal storage device; 11. Raw coal storage bin; 12. Baffle; 20. Transportation device; 30. Coal grinding device; 31. Hot gas inlet; 32. Pulverized coal outlet; 33. First pulverized coal pipeline; 34. Explosion-proof gate; 40. Bag filter; 41. Exhaust fan; 42. Pulverized coal storage bin; 43. Second pulverized coal pipeline; 44. Coal powder meter at the kiln head; 45. Coal powder meter at the decomposition furnace; 46. Burner at the kiln head; 47. Burner at the decomposition furnace; 48. Dust collection bag; 50. CO 2 storage system; 51 gas pipeline.

[0021] The following specific embodiments will further illustrate the present utility model in conjunction with the above-mentioned drawings. Specific Embodiments

[0022] For ease of understanding the present utility model, the present utility model will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present utility model are shown in the drawings. However, the present utility model can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present utility model more thorough and comprehensive.

[0023] It should be noted that when an element is referred to as being "fixedly provided on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this utility model belongs. The terms used in the description of this utility model herein are for the purpose of describing specific embodiments only and are not intended to limit this utility model. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0025] Specifically, as Figure 1 shown, the coal combustion system of the cement production line provided in this embodiment includes: a raw coal storage device 10, the raw coal storage device 10 includes at least two raw coal storage bins 11, the raw coal storage bins 11 are used to store raw coal of different qualities, a transportation device 20 is provided below the raw coal storage bins 11, and a coal grinding device 30 is provided at one end of the transportation device 20 away from the raw coal storage bins 11. The coal grinding device 30 is used to grind raw coal of different qualities. The coal grinding device 30 includes a hot gas inlet 31 and a pulverized coal outlet 32. The pulverized coal outlet 32 is communicated with a bag filter 40 through a first pulverized coal pipeline 33. An air extraction fan 41 is provided on one side of the bag filter 40. The air extraction fan 41 is used to extract the air in the bag filter to make the inside of the bag filter 40 in a negative pressure and collect the ground pulverized coal through negative pressure. A pulverized coal storage bin 42 corresponding to the raw coal storage bin 11 is provided at the bottom of the bag filter 40. A second pulverized coal pipeline 43 is correspondingly provided at the bottom of each pulverized coal storage bin 42. The pulverized coal in the pulverized coal storage bin 42 is transported to the corresponding burner through the second pulverized coal pipeline 43 for combustion.

[0026] Optionally, in this embodiment, the raw coal storage device 10 includes two raw coal storage bins 11. The two raw coal storage bins 11 are respectively used to store two kinds of raw coal with different calorific values. The coal grinding device 30 includes a hot gas inlet 31. Hot gas is introduced into the hot gas inlet, which can dry the ground pulverized coal and improve the pulverized coal transfer effect. That is, high-calorific-value raw coal and low-calorific-value raw coal. Two kinds of pulverized coal with different calorific values are correspondingly stored in the two pulverized coal storage bins 42. It can be understood that the two kinds of pulverized coal are respectively ground from the two kinds of raw coal. The burner includes a kiln head burner 46 and a precalciner burner 47. The thrust of the kiln head burner 46 is greater than that of the precalciner burner 47. The calorific value of the pulverized coal in the pulverized coal storage bin connected to the kiln head burner 46 is higher than that of the pulverized coal in the pulverized coal storage bin connected to the precalciner burner 47.

[0027] In specific implementation, first, high calorific value and high volatile coal and low calorific value and low volatile coal are respectively placed in two raw coal storage bins 11. Then, one type of coal is introduced into the coal grinding device 30 through the transportation device 20. Schematically, in this embodiment, high calorific value coal powder is ground first and then low calorific value coal powder is ground. Specifically, the high calorific value raw coal storage bin is opened, and the low calorific value raw coal storage bin is closed. First, the high calorific value coal is introduced into the coal grinding device. The transportation device 20 can be a chain conveyor, and the coal grinding device 30 can be a vertical grinding mill. The air extraction fan 41 is started to make the inside of the bag filter 40 in a negative pressure state. Based on the negative pressure, the ground high calorific value coal powder is sucked into the bag filter 40 through the first coal powder pipeline 33. The bag filter 40 is communicated with the high calorific value coal powder storage bin. Finally, the high calorific value coal powder is transported to the kiln head burner through the corresponding second coal powder pipeline 43 and is sprayed and burned through the nozzle in the kiln head burner. By utilizing the characteristics of high calorific value and high volatility, high-temperature and rapid calcination is achieved. When low calorific value coal powder needs to be ground, the high calorific value raw coal storage bin is closed, and the low calorific value raw coal storage bin is opened. After a first preset time, the bag filter 40 is switched to be communicated with the low calorific value coal powder storage bin, and the low calorific value coal powder is transported to the decomposition furnace burner through the corresponding second coal powder pipeline 43 to achieve uniform and stable deacidification of the raw material at the required temperature. Optionally, the coal powder storage bin 42 can store a certain amount of coal powder, such as 100 tons, to ensure that there is still coal powder supply for the kiln head burner and the decomposition furnace burner during the short-term shutdown of the coal grinding device 30.

[0028] It can be understood that in some alternative embodiments, low calorific value coal powder can also be ground first and then high calorific value coal powder is ground. The process is similar and will not be elaborated here. In order to ensure the efficiency of the kiln head burner, impurities in the high calorific value coal powder bin should be minimized and the purity should be improved. Therefore, when switching from low calorific value coal powder to high calorific value coal powder, after adding high calorific value raw coal into the coal grinding device, the time for the bag filter 40 to be communicated with the low calorific value coal powder storage bin is appropriately extended to minimize the entry of low calorific value coal powder in the system into the high calorific value coal powder bin as much as possible. The coal combustion system for the cement production line provided by this application transports high calorific value coal powder to the kiln head for spraying and burning through different paths, and transports low calorific value coal powder to the decomposition furnace for spraying and burning. It burns coals of different qualities specifically, which not only ensures the combustion efficiency of different burners, but also reduces the use of high-quality coal and lowers the cost. Further, different raw coals are respectively transported to the coal grinding device for grinding through the transportation device, and the ground coal powders of different types are collected by means of extracting negative pressure by the air extraction fan, and different coal powders are transported to the corresponding burners according to needs. The working efficiency is high, and only the number of storage bins is increased, while the transportation device, the coal grinding device, and the bag filter can be shared, so that the transportation of coal powder through different paths can be realized, and the investment and transformation cost can be reduced.

[0029] Further, in this embodiment, a kiln head coal powder meter 44 is provided between the kiln head burner 46 and the corresponding coal powder storage bin, and a precalciner coal powder meter 45 is provided between the precalciner burner 47 and the corresponding coal powder storage bin. The amount of coal powder entering the corresponding burner can be accurately controlled through the two meters. In this embodiment, two cylindrical storage tanks can be used as the raw coal storage bins to store raw coal of different qualities respectively; such as Figure 2 and Figure 3 As shown, in some alternative embodiments, the raw coal storage device 10 can also be a conical storage bucket with a larger upper part and a smaller lower part. A baffle 12 is provided inside the conical storage bucket. The inner cavity of the storage bucket is partitioned into two storage cavities by the baffle 12 to form two raw coal storage bins. Two types of raw coal with different calorific values are stored in the two storage cavities respectively. That is, the inner cavity of the storage bucket is partitioned into two storage cavities by the baffle 12 to form two raw coal storage bins 11.

[0030] Further, in this embodiment, a plurality of dust collection bags 48 are provided inside the bag filter 40. The dust collection bags 48 are used to filter and collect the coal powder ground by the coal grinding device 30. The coal powder ground by the coal grinding device 30 is transported to the bag filter 40 by negative pressure through the first coal powder pipeline 33 and adheres to the dust collection bags 48. Optionally, the dust collection bags 48 can be arranged dust collection bags, and the coal powder adsorbed on the dust collection bags 48 can be transported into the coal powder storage bin 42 by means of compressed air blowing. Optionally, an explosion-proof gate 34 is provided on the first coal powder pipeline 33 to prevent dust explosion in the system. Optionally, in this embodiment, the combustion system further includes a CO 2 storage system 50, and the CO 2 storage system 50 stores CO 2 , and the CO 2 storage system 50 is communicated with the bag filter 40 and the coal grinding device 30 respectively through a gas pipeline 51 to inject inert gas into the coal grinding device 30 and the bag filter 40 during the period when coal powder grinding is stopped, reducing the risk of dust explosion in the system.

[0031] In summary, the coal combustion system for the cement production line provided by the present utility model includes two raw coal storage bins 11 for storing raw coal of different qualities. Through the transportation device 20, coal grinding device 30, bag filter 40, and two pulverized coal storage bins, the raw coal of different qualities is ground and then transported to different pulverized coal storage bins. Then, through different burners, the pulverized coal is burned. Through different paths, the pulverized coal with high calorific value is transported to the kiln head for coal injection combustion, and the pulverized coal with low calorific value is transported to the decomposition furnace for coal injection combustion. The coal of different qualities is burned specifically, which not only ensures the combustion efficiency of different burners but also reduces the use of high-quality coal and lowers the cost. Further, different raw coals are transported to the coal grinding device for grinding respectively through the transportation device, and the pulverized coal after different grindings is collected by means of a suction air fan to create negative pressure, and different pulverized coals are transported to the corresponding burners as needed. The working efficiency is high. Only the number of storage bins is increased, while the transportation device, coal grinding device, and bag filter can be shared, so that the transportation of pulverized coal through different paths can be realized, and the investment and transformation cost can be reduced, which is suitable for large-scale promotion.

[0032] It should be noted that the above implementation process is only to illustrate the feasibility of the present application, but this does not mean that the coal combustion system for the cement production line of the present application only has the above implementation process. On the contrary, as long as the coal combustion system for the cement production line of the present application can be implemented, it can be included in the feasible implementation solutions of the present application.

[0033] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0034] The above embodiments only represent several implementation manners of the present utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent of the present utility model. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present utility model, several modifications and improvements can still be made, and these all belong to the protection scope of the present utility model. Therefore, the protection scope of the patent of the present utility model should be subject to the appended claims.

Claims

1. A coal combustion system for a cement production line, characterized in that: include: A raw coal storage device, the raw coal storage device comprises at least two raw coal storage bins, the raw coal storage bins are used to store raw coal of different qualities, a transportation device is arranged below the raw coal storage bin, a coal grinding device is arranged at one end of the transportation device away from the raw coal storage bin, the coal grinding device is used to grind raw coal of different qualities, the coal grinding device comprises a hot air inlet and a coal powder outlet, the coal powder outlet is connected to a bag dust collector through a first coal powder pipeline, an exhaust windmill is arranged on one side of the bag dust collector, the exhaust windmill is used to extract air in the bag dust collector so that the bag dust collector has a negative pressure and collects the ground coal powder through the negative pressure, a coal powder storage bin corresponding to the raw coal storage bin is arranged at the bottom of the bag dust collector, and a second coal powder pipeline is arranged at the bottom of each coal powder storage bin to transport the coal powder in the coal powder storage bin to the corresponding burner for combustion.

2. The coal combustion system for cement production line according to claim 1, characterized in that: The combustion system includes two raw coal storage bins and two coal powder storage bins. The two raw coal storage bins respectively store two kinds of raw coal with different calorific values. The two coal powder storage bins correspondingly store two kinds of coal powder with different calorific values. The burner includes a kiln head burner and a decomposition furnace burner. The calorific value of the coal powder in the coal powder storage bin connected to the kiln head burner is higher than the calorific value of the coal powder in the coal powder storage bin connected to the decomposition furnace burner.

3. The coal combustion system for cement production line according to claim 2, characterized in that: A kiln head coal powder meter is provided between the kiln head burner and the correspondingly connected coal powder storage bin, and a decomposition furnace coal powder meter is provided between the decomposition furnace burner and the correspondingly connected coal powder storage bin.

4. The coal combustion system for cement production line according to claim 2, characterized in that: The thrust of the kiln head burner is greater than the thrust of the calciner burner.

5. The coal combustion system for cement production line according to claim 2, characterized in that: The raw coal storage device is a conical storage barrel, and a baffle is arranged inside the conical storage barrel. The baffle is used to separate the inner cavity of the conical storage barrel into two storage cavities to form two raw coal storage bins.

6. The coal combustion system for cement production line according to claim 1, characterized in that: A plurality of dust collecting bags are arranged in the bag dust collector, and the dust collecting bags are used for filtering and collecting the coal powder ground by the coal grinding device.

7. The coal combustion system for cement production line according to claim 1, characterized in that: The first pulverized coal pipeline is provided with an explosion-proof gate.

8. The coal combustion system for cement production line according to claim 1, characterized in that: The combustion system further comprises a CO2 storage system, and the CO2 storage system is respectively connected with the bag dust collector and the coal grinding device through a gas pipeline.

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