Coal mill separate grinding control method

Abstract

The present application relates to cement coal mill technical field, specifically to a kind of coal mill respectively grinding control method, comprising: setting tail silo weight high low limit and head silo weight high low limit, the head silo is used to store coal powder, the tail silo is used to store coal powder and coal gangue powder mixture, the high low limit includes high limit and low limit;Real-time monitoring tail silo weight and head silo weight, and real-time monitoring coal gangue scale's working state;Determine whether tail silo weight is lower than tail silo weight low limit, or whether head silo weight is higher than head silo weight high limit;Determine whether head silo weight is lower than head silo weight low limit, or whether tail silo weight is higher than tail silo weight high limit, and determine whether the working state of coal gangue scale is stop state, control to open coal gangue scale or stop coal gangue scale.The present application can control coal mill feeding ratio by controlling to open coal gangue scale and stop coal gangue scale, solves the technical problem that prior art cannot make full use of coal mill downtime.

Description

Technical Field

[0001] This invention relates to the field of cement coal mill technology, and more specifically to a method for controlling the separate grinding of coal. Background Technology

[0002] A coal mill is a machine that crushes and grinds coal into pulverized coal. It is an important auxiliary equipment in cement production. Grinding coal involves breaking down coal lumps to continuously increase their surface area. To increase the surface area of ​​pulverized coal, the binding forces between the solid molecules of the coal lumps must be overcome. Coal lumps are ground into pulverized coal mainly through three methods: crushing, impact crushing, and grinding. Among these, crushing consumes the least energy, while grinding consumes the most. In cement production, when the rotary kiln is operating, raw materials are fed in from the higher end of the kiln (kiln tail), while fuel (pulverized coal) and combustion air are injected from the lower end (kiln head). The pulverized coal reacts chemically with the combustion air and burns, releasing heat to calcine the raw materials into clinker. Since many alternative fuels are generated in the cement production process, and these alternative fuels also release heat when burned (e.g., scrap materials, plastics), using alternative fuels reduces the rotary kiln's demand for pulverized coal, and the coal mill's operating time can be reduced accordingly, thus allowing for sufficient downtime. Currently, the sufficient downtime of coal mills cannot be fully utilized, leaving them idle during downtime, which is detrimental to improving their performance. Summary of the Invention

[0003] This invention provides a method for controlling the separate grinding of coal, which solves the technical problem that the existing technology cannot make full use of the downtime of the coal mill.

[0004] The basic solution provided by this invention is: a coal mill separate grinding control method, including:

[0005] Reamer control, the reamer including a first reamer and a second reamer, the first reamer and the second reamer being used to convey pulverized coal, a mixture of pulverized coal and coal gangue powder, including:

[0006] S1. Set high and low limits for the weight of the tail silo and the head silo. The head silo is used to store pulverized coal, and the tail silo is used to store a mixture of pulverized coal and coal gangue powder. The high and low limits include a high limit and a low limit.

[0007] S2. Real-time monitoring of the tail bin weight and head bin weight, wherein the tail bin weight is the weight of the mixture of coal powder and coal gangue powder, and the head bin weight is the weight of coal powder, and real-time monitoring of the working status of the coal gangue scale, wherein the working status includes running status and shutdown status.

[0008] S3. Determine whether the weight of the tail bin is lower than the lower limit of the tail bin weight, or whether the weight of the head bin is higher than the upper limit of the head bin weight; determine whether the weight of the head bin is lower than the lower limit of the head bin weight, or whether the weight of the tail bin is higher than the upper limit of the tail bin weight; and determine whether the working status of the coal gangue scale is the shutdown state:

[0009] If the weight of the tail bin is lower than the lower limit of the tail bin weight, or the weight of the head bin is higher than the upper limit of the head bin weight, and the coal gangue scale is in a working state or a stopped state, both the first and second cutters will be moved from the head bin to the tail bin; at the same time, the coal gangue scale will be turned on after the first preset time period to ensure that the coal gangue scale is in a running state.

[0010] If the weight of the head bin is lower than the lower limit of the head bin weight, or the weight of the tail bin is higher than the upper limit of the tail bin weight, and the coal gangue scale is in the running state, the coal gangue scale will be stopped after the second preset time period to ensure that the coal gangue scale is in the stopped state, and the first and second cutters will be transferred from the tail bin to the head bin after the third preset time period.

[0011] The working principle and advantages of this invention are as follows: After using alternative fuels in the coal mill, the demand for coal decreases, and the coal mill has sufficient time to shut down. In this solution, the coal mill is fully utilized. For the same coal mill, alternative fuel (such as coal gangue powder) is added to the tail bin to reduce coal costs without significantly affecting the kiln condition. An automated program is used for control, and the control principle is as follows: The coal mill does not stop during the grinding process. By monitoring the changes in the weight of the head bin and the tail bin, the operation of the coal gangue scale and the powder are controlled. Whether the finished product enters the head silo or the tail silo is determined by automatically starting and stopping the coal gangue scale, thus ensuring that the ground alternative fuel enters the tail silo: When switching to the head silo, the coal gangue scale is stopped, and the coal mill grinds pure coal, with all the pulverized coal entering the head silo; when switching to the tail silo, the coal gangue scale is started, and the coal mill grinds a mixture of coal and coal gangue, with all the finished mixture entering the tail silo. Since the calorific value of coal is higher than that of alternative fuels, such as coal gangue, the downtime of the coal mill is fully utilized to grind alternative fuels. By controlling the start and stop of the coal gangue scale, the feeding ratio of the coal mill can be adjusted.

[0012] This invention makes full use of the downtime of coal mills to grind alternative fuels. By controlling the operation of the coal and gangue scales, the feeding ratio of the coal mill can be controlled and adjusted, thus solving the technical problem that the existing technology cannot fully utilize the downtime of coal mills.

[0013] Furthermore, before transferring the first and second cutters from the tail bin to the head bin, the coal mill is washed and ground according to the third preset time period.

[0014] The beneficial effects are: stopping the coal gangue scale 15 minutes in advance, using pure coal with higher calorific value for grinding, and carrying away all the alternative fuels with lower calorific value (such as coal gangue) remaining in the entire coal mill system into the tail bin, ensuring that the finished product entering the head bin is pure coal powder with higher calorific value, and ensuring that the high-quality coal powder in the head bin is more conducive to the calcination of clinker.

[0015] Furthermore, the first and second reamers rotate clockwise to enter the tail compartment, and the first and second reamers rotate counterclockwise to enter the head compartment.

[0016] The beneficial effects are: the conveying process of coal and coal gangue can be controlled by the forward and reverse rotation of the first and second cutters, which is easy to implement and easy to control.

[0017] Furthermore, the coal gangue scale is a belt scale.

[0018] The beneficial effects are: the belt scale technology is mature, easy to measure and control accurately; coal gangue is a solid waste discharged during coal mining and washing, which is a blackish-gray rock with low carbon content and harder than coal. Other alternative fuels can be waste materials with calorific value. By making full use of its calorific value, the amount of coal used can be appropriately reduced.

[0019] Furthermore, the first preset time period is 5 seconds, and the second preset time period is 5 seconds.

[0020] The beneficial effects are as follows: if the weight of the tail bin is lower than the lower limit of the tail bin weight, or the weight of the head bin is higher than the upper limit of the head bin weight, and the coal gangue scale is in a working state or a stopped state, the coal gangue scale will be turned on after 5 seconds; if the weight of the head bin is lower than the lower limit of the head bin weight, or the weight of the tail bin is higher than the upper limit of the tail bin weight, and the coal gangue scale is in a running state, the coal gangue scale will be turned off after 5 seconds; setting the time for turning on and off the coal gangue scale in this way can adjust the amount of coal used as quickly as possible.

[0021] Furthermore, the third preset time period is 15 minutes.

[0022] The beneficial effects are: ensuring that the coal mill has sufficient washing time, preventing the washing effect from being affected by too short a washing time and leaving impurities or residues, and also avoiding over-washing due to too long a washing time, thus saving washing time. Attached Figure Description

[0023] Figure 1 This is a flowchart of an embodiment of the coal mill separate grinding control method of the present invention. Detailed Implementation

[0024] The following detailed explanation illustrates the specific implementation methods:

[0025] Example

[0026] The basic implementation examples are as follows: Figure 1As shown, the coal mill's grinding control method includes:

[0027] Reamer control, the reamer including a first reamer and a second reamer, the first reamer and the second reamer being used to convey pulverized coal, a mixture of pulverized coal and coal gangue powder, including:

[0028] S1. Set high and low limits for the weight of the tail silo and the head silo. The head silo is used to store pulverized coal, and the tail silo is used to store a mixture of pulverized coal and coal gangue powder. The high and low limits include a high limit and a low limit.

[0029] S2. Real-time monitoring of the tail bin weight and head bin weight, wherein the tail bin weight is the weight of the mixture of coal powder and coal gangue powder, and the head bin weight is the weight of coal powder, and real-time monitoring of the working status of the coal gangue scale, wherein the working status includes running status and shutdown status.

[0030] S3. Determine whether the weight of the tail bin is lower than the lower limit of the tail bin weight, or whether the weight of the head bin is higher than the upper limit of the head bin weight; determine whether the weight of the head bin is lower than the lower limit of the head bin weight, or whether the weight of the tail bin is higher than the upper limit of the tail bin weight; and determine whether the working status of the coal gangue scale is the shutdown state:

[0031] If the weight of the tail bin is lower than the lower limit of the tail bin weight, or the weight of the head bin is higher than the upper limit of the head bin weight, and the coal gangue scale is in a working state or a stopped state, both the first and second cutters will be moved from the head bin to the tail bin; at the same time, the coal gangue scale will be turned on after the first preset time period to ensure that the coal gangue scale is in a running state.

[0032] If the weight of the head bin is lower than the lower limit of the head bin weight, or the weight of the tail bin is higher than the upper limit of the tail bin weight, and the coal gangue scale is in the running state, the coal gangue scale will be stopped after the second preset time period to ensure that the coal gangue scale is in the stopped state, and the first and second cutters will be transferred from the tail bin to the head bin after the third preset time period.

[0033] As one preferred approach: before transferring the first and second cutters from the tail bin to the head bin, the coal mill is washed during a third preset time period. The coal gangue scale is stopped 15 minutes in advance, and high-calorific-value pure coal is used for grinding. This process carries away all residual low-calorific-value alternative fuels (such as coal gangue) from the entire coal mill system into the tail bin, ensuring that the finished product entering the head bin is high-calorific-value pure coal powder. High-quality coal powder from the head bin is more conducive to clinker calcination. The third preset time period is greater than or equal to 15 minutes to ensure sufficient washing time for the coal mill. This prevents insufficient washing time from affecting the washing effect and leaving impurities or residues, while also avoiding over-washing due to excessive washing time, thus saving washing time.

[0034] As a preferred option: the first and second cutters rotate clockwise to enter the tail bin, and counterclockwise to enter the head bin. The forward and reverse rotation of the first and second cutters controls the conveying process of coal and gangue, which is easy to implement and control. The gangue is referred to as a belt scale. If other alternative fuels are used, the raw coal scale and gangue scale can be replaced with scale #1 and scale #2. Belt scale technology is mature and easy to implement. Gangue is a solid waste discharged during coal mining and washing; it is a blackish-gray rock with low carbon content and harder than coal. Other alternative fuels can be used... Since these are waste materials with calorific value, fully utilizing their calorific value can appropriately reduce coal consumption. The first preset time period is 5 seconds, and the second preset time period is 5 seconds. If the weight of the tail bin is lower than the lower limit of the tail bin weight, or the weight of the head bin is higher than the upper limit of the head bin weight, and the coal gangue scale is in the working state or the shutdown state, the coal gangue scale will be turned on after 5 seconds. If the weight of the head bin is lower than the lower limit of the head bin weight, or the weight of the tail bin is higher than the upper limit of the tail bin weight, and the coal gangue scale is in the working state, the coal gangue scale will be turned off after 5 seconds. By setting the time for turning on and off the coal gangue scale in this way, the amount of coal consumed can be adjusted as quickly as possible.

[0035] In this embodiment, after the coal mill uses alternative fuel, the demand for coal decreases, and the coal mill has sufficient time to shut down. In this solution, the coal mill is fully utilized. For the same coal mill, coal gangue powder is added to the tail bin to reduce coal costs without significantly affecting the kiln condition. An automated program is used for control, and the control principle is as follows: the coal mill does not stop during the grinding process. The operation of the coal gangue scale and the entry of the ground product into the head bin are controlled by monitoring changes in the weight of the head and tail bins. It is the tail hopper. By automatically starting and stopping the coal gangue scale, the purpose of grinding alternative fuels into the tail hopper is met: when switching to the head hopper, the coal gangue scale is stopped, the coal mill grinds pure coal, and all the coal powder enters the head hopper; when switching to the tail hopper, the coal gangue scale is started, the coal mill grinds a mixture of coal and coal gangue, and all the finished mixture enters the tail hopper; since the calorific value of coal is higher than that of alternative fuels, such as coal gangue, the downtime of the coal mill is fully utilized to grind alternative fuels. By controlling the start and stop of the coal gangue scale, the feeding ratio of the coal mill can be adjusted.

[0036] The above descriptions are merely embodiments of the present invention. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for separate grinding control of a coal mill, characterized in that, The application relates to a hinge cutter control, which comprises a first hinge cutter and a second hinge cutter for conveying coal powder and a mixture of coal powder and coal gangue powder. S1, setting high and low limit values of tail bin weight and head bin weight, the head bin being used for storing coal powder, the tail bin being used for storing a mixture of coal powder and coal gangue powder, and the high and low limit values comprising high limit values and low limit values; S2, monitoring the tail bin weight and the head bin weight in real time, the tail bin weight being the weight of the mixture of coal powder and coal gangue powder, the head bin weight being the weight of the coal powder, and monitoring the working state of the coal gangue scale in real time, the working state comprising a running state and a shutdown state; S3, judging whether the tail bin weight is lower than the tail bin weight low limit value or whether the head bin weight is higher than the head bin weight high limit value; judging whether the head bin weight is lower than the head bin weight low limit value or whether the tail bin weight is higher than the tail bin weight high limit value; and judging whether the working state of the coal gangue scale is the shutdown state; If the tail bin weight is lower than the tail bin weight low limit value or the head bin weight is higher than the head bin weight high limit value, and the working state of the coal gangue scale is the shutdown state, the first hinge cutter and the second hinge cutter are transferred from the head bin into the tail bin, and the coal gangue scale is started after a first preset time period, so that the working state of the coal gangue scale is ensured to be the running state, the first preset time period being 5 seconds, and the second preset time period being 5 seconds; If the head bin weight is lower than the head bin weight low limit value or the tail bin weight is higher than the tail bin weight high limit value, and the working state of the coal gangue scale is the running state, the coal gangue scale is stopped after a second preset time period, so that the working state of the coal gangue scale is ensured to be the shutdown state, and the first hinge cutter and the second hinge cutter are transferred from the tail bin into the head bin after a third preset time period, and the coal mill is washed and ground according to the third preset time period before the first hinge cutter and the second hinge cutter are transferred from the tail bin into the head bin, the third preset time period being 15 minutes. The first hinge cutter and the second hinge cutter rotate forward to enter the tail bin, and the first hinge cutter and the second hinge cutter rotate reversely to enter the head bin.

2. The coal mill separate grinding control method of claim 1, wherein, The coal gangue scale is a belt scale.

3. The coal mill separate grinding control method of claim 1, wherein, ​

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