Anti-deflagration method of coal mill and anti-deflagration device

Abstract

The invention relates to the technical field of coal mills, in particular to a deflagration prevention method for a coal mill, which comprises a nitrogen charging device consisting of a nitrogen cylinder, a pressure reducing valve and four electromagnetic valves, the four electromagnetic valves comprise the first electromagnetic valve, the second electromagnetic valve, the third electromagnetic valve and the fourth electromagnetic valve, the first electromagnetic valve, the second electromagnetic valve, the third electromagnetic valve and the fourth electromagnetic valve are connected with the nitrogen cylinder through the pressure reducing valve, and the other ends of the first electromagnetic valve, the second electromagnetic valve, the third electromagnetic valve and the fourth electromagnetic valve are connected with the coal mill through pipelines. The nitrogen charging frequency of the rapid nitrogen charging device is controlled according to the feeding amount of the Indonesia coal sub-ring in the coal mill; wherein nitrogen is injected into the coal mill through a nitrogen charging device so as to prevent detonation of the coal mill; gas in the coal mill is pumped out through the sucking pump, the sparking plug ignites alcohol to consume oxygen in the pumped gas, the treated gas is guided into the pipeline again, and therefore cyclic utilization of nitrogen is achieved.

Description

Technical Field

[0001] The present invention relates to the field of coal mills, and particularly to an anti-explosion and anti-combustion method and device for coal mills. Background Art

[0002] According to the records of the prior art, in order to reduce the coal combustion cost, multiple coal mills in power plants have been co-firing high-volatile coal types such as Indonesian coal and lignite, which are extremely prone to deflagration.

[0003] One way is to introduce a steam source from auxiliary steam and connect it near the air chamber of the coal mill for use as fire-fighting steam. However, since the fire-fighting steam is likely to become condensate when in standby, if the condensate is not drained in time, it cannot be sprayed into the coal mill in the form of steam during use, but enters the burning pulverized coal in an insufficient amount of water, which will generate water gas and make the situation more dangerous. If it is sprayed in the form of water, the pulverized coal will turn into water coal slurry, and the fire may be extinguished, but the metal components of the mill will be deformed due to the cold, and the water coal slurry is prone to caking and scaling, and accumulating at the edge of the coal mill will increase the risk of deflagration of the coal mill.

[0004] Moreover, the current fire-fighting steam interface is located at the lower part of the coal mill, which will cause a certain delay if deflagration occurs above; and the current logic for automatically opening the fire-fighting steam electric valve only has a judgment condition that the temperature of the air-powder mixture at the outlet of the coal mill separator is greater than 130 °C. If the temperature reaches 130 °C, deflagration has basically occurred, which will cause a greater impact on the coal mill and cannot effectively prevent the occurrence of deflagration of the coal mill in advance. Therefore, an anti-explosion and anti-combustion method and device for coal mills are proposed to solve the above problems. Summary of the Invention

[0005] The object of the present invention is to provide an anti-explosion and anti-combustion method for coal mills, aiming to solve the problem that introducing steam into the coal mill will damage the internal components of the coal mill.

[0006] The above technical problems are solved by the following technical solutions: The present invention provides the following technical solutions: An anti-explosion and anti-combustion method for coal mills, including,

[0007] An anti-explosion and anti-combustion method for coal mills, including,

[0008] The coal mill is connected with a nitrogen charging device;

[0009] When the coal mill is operating, the nitrogen charging device charges nitrogen into the coal mill, and the nitrogen charged into the coal mill occupies the oxygen proportion of the air in the coal mill.

[0010] As a preferred implementation mode of the anti-explosion and anti-combustion method for coal mills of the present invention: According to the dynamic changes of the coal types co-fired in the coal mill, the coal feeding amount of the coal feeder, and the operating parameters, the opening and closing frequency and the opening duration of the nitrogen charging device are regulated.

[0011] In a preferred embodiment of the method for preventing explosion and deflagration of the coal mill of the present invention: when the coal mill is operating, different trigger logics are set for the coal feeding amount of the coal feeder, and the regular opening time of the solenoid valve is set in the trigger logic.

[0012] In a preferred embodiment of the method for preventing explosion and deflagration of the coal mill of the present invention: when the nitrogen filling device fills nitrogen into the coal mill, nitrogen enters the coal mill from multiple directions.

[0013] In a preferred embodiment of the method for preventing explosion and deflagration of the coal mill of the present invention: the nitrogen filling device consists of a nitrogen cylinder and four solenoid valves;

[0014] When the nitrogen filling device fills nitrogen into the coal mill, multiple groups of solenoid valves are opened synchronously;

[0015] A pressure reducing valve is connected between the nitrogen cylinder and the solenoid valve.

[0016] The beneficial effect of the method for preventing explosion and deflagration of the coal mill of the present invention is that nitrogen replaces steam, which can avoid the occurrence of deflagration by changing the combustion environment inside the coal mill. At the same time, the nitrogen filling frequency is controlled according to the input amount of Indonesian coal sub-ring, so that the internal environment is filled with nitrogen to ensure the normal operation of the coal mill.

[0017] Another object of the present invention is to provide an explosion-proof device, aiming to solve the problem that the maintenance time after nitrogen filling is short, resulting in excessive nitrogen consumption.

[0018] To solve the above technical problems, the present invention also provides the following technical solution: an explosion-proof device, including a method for preventing explosion and deflagration of a coal mill,

[0019] An oxygen-consuming component, which includes a cavity, and the cavity is connected with a combustion mechanism;

[0020] The combustion mechanism includes fuel;

[0021] When the fuel burns in the cavity, the oxygen content in the gas entering the cavity is reduced.

[0022] As a preferred solution of the explosion-proof device of the present invention, among them: the four solenoid valves include a first solenoid valve, a second solenoid valve, a third solenoid valve and a fourth solenoid valve. The first solenoid valve, the second solenoid valve, the third solenoid valve and the fourth solenoid valve are connected with the nitrogen cylinder through a pressure reducing valve, and the other ends of the first solenoid valve, the second solenoid valve, the third solenoid valve and the fourth solenoid valve are connected with the coal mill through pipelines.

[0023] As a preferred solution of the explosion-proof device of the present invention, among them: the cavity is an air box, the combustion mechanism includes a spark plug, a lower liquid pipe, a fifth solenoid valve and an alcohol tank. The surface of the air box is connected with an intake pipe and an exhaust pipe. The other end of the intake pipe is connected with an air extraction pump, and the other end of the air extraction pump is connected with the coal mill.

[0024] As a preferred embodiment of the explosion-proof device of the present invention, wherein: the other end of the air outlet pipe is connected to a sixth solenoid valve, and the other end of the sixth solenoid valve is connected to a pressure reducing valve.

[0025] As a preferred embodiment of the explosion-proof device of the present invention, wherein: the lower end of the liquid discharge pipe is connected to an atomizing nozzle, and a liquid supply pump is arranged inside the alcohol tank.

[0026] The beneficial effect of the explosion-proof device of the present invention is that: the air inside the coal mill is pumped out by an air extraction pump, and the spark plug ignites alcohol to consume the oxygen in the extracted air, and the processed air is re-introduced into the pipeline, thereby realizing the recycling of nitrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below only relate to some embodiments of the present invention and do not limit the present invention. Among them:

[0028] Figure 1 It is a schematic diagram of the overall structure in the present invention.

[0029] Figure 2 It is a schematic diagram of the structure of the oxygen-consuming component in the present invention.

[0030] Figure 3 It is a schematic cross-sectional structure diagram of the air box in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] In order to enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below in conjunction with the specific embodiments and the accompanying drawings.

[0032] The terms used in the present invention are those general terms that are currently widely used in the art in consideration of the functions of the present invention, but these terms can change according to the intentions of those of ordinary skill in the art, precedents or new technologies in the art. In addition, specific terms can be selected by the applicant, and in this case, their detailed meanings will be described in the detailed description of the present invention. Therefore, the terms used in the specification should not be understood as simple names, but based on the meanings of the terms and the overall description of the present invention.

[0033] Example 1, referring to Figures 1 to 3 , this embodiment provides a method for preventing explosion and ignition of a coal mill, including that the coal mill is connected to a nitrogen filling device;

[0034] When the coal mill is operating, the nitrogen filling device fills nitrogen into the coal mill, and the nitrogen filled into the coal mill occupies the oxygen proportion of the air inside the coal mill.

[0035] Regulate the opening and closing frequency and the opening duration of the nitrogen filling device according to the dynamic changes of the coal type co-fired in the coal mill, the coal quantity of the coal feeder, and the operating parameters.

[0036] When the coal mill is operating, set different trigger logics through the coal quantity of the coal feeder, and set the regular opening time of the solenoid valve in the trigger logic.

[0037] When the nitrogen filling device fills nitrogen into the coal mill, nitrogen enters the coal mill from multiple directions.

[0038] The nitrogen filling device consists of a nitrogen cylinder 1 and four solenoid valves;

[0039] When the nitrogen filling device fills nitrogen into the coal mill, multiple groups of solenoid valves open synchronously;

[0040] A pressure reducing valve 2 is connected between the nitrogen cylinder 1 and the solenoid valve.

[0041] Furthermore, when the Indonesian coal sub-ring is put into operation and the coal quantity is greater than 45 t / h, the nitrogen filling device is triggered to act once every two hours, and the action time is 10 seconds.

[0042] When the Indonesian coal sub-ring is put into operation and the coal quantity is between 40 - 45 t / h, the nitrogen filling device is triggered to act once every hour, and the action time is 10 seconds.

[0043] When the Indonesian coal sub-ring is put into operation and the coal quantity is between 30 - 40 t / h, the nitrogen filling device is triggered to act once every half hour, and the action time is 10 seconds.

[0044] When the Indonesian coal sub-ring is put into operation and the coal quantity is less than 30 t / h, the nitrogen filling device is automatically triggered to act until the operator manually exits the sub-ring after the coal mill is purged, and the nitrogen filling device resumes.

[0045] The four solenoid valves include a first solenoid valve 3, a second solenoid valve 4, a third solenoid valve 5, and a fourth solenoid valve 6. The first solenoid valve 3, the second solenoid valve 4, the third solenoid valve 5, and the fourth solenoid valve 6 are connected to the nitrogen cylinder 1 through the pressure reducing valve 2, and the other ends of the first solenoid valve 3, the second solenoid valve 4, the third solenoid valve 5, and the fourth solenoid valve 6 are connected to the coal mill through pipelines.

[0046] During the use process: Control the nitrogen filling frequency of the rapid nitrogen filling device according to the feeding amount of the Indonesian coal sub-ring put into the coal mill. When it is necessary to fill nitrogen into the coal mill, the first solenoid valve 3, the second solenoid valve 4, the third solenoid valve 5, and the fourth solenoid valve 6 open, then nitrogen directly enters the coal mill, reducing the oxygen in the coal mill and avoiding deflagration.

[0047] Nitrogen is used as a flame retardant to isolate the air and cut off the oxygen required for combustion. It has no damage to the metal parts of the coal mill and can prevent water vapor from corroding the coal mill, so the system can be quickly and efficiently restored to normal operation. The coal mill air chamber and the top separator are about five meters apart, and the probability of deflagration is also the highest at these two locations. Spraying nitrogen from four directions at the same time can quickly alleviate the expansion trend of the deflagration, which has a greater advantage in fire extinguishing time compared with the single-point injection of the original process. The trigger condition of the original fire steam injection is the single condition of the set temperature of the air-powder mixture at the outlet of the coal mill separator, and the deflagration has basically occurred when the temperature is reached, and it cannot play a preventive effect in advance. The action of the nitrogen filling device is triggered by the different amount of coal during the normal operation of the coal mill to effectively curb the occurrence of deflagration.

[0048] Example 2, reference Figures 1 to 3 This embodiment provides an explosion-proof device, including a coal mill explosion-proof method.

[0049] The other end of the air inlet pipe 82 is connected to the air extraction pump 7, and the other end of the air extraction pump 7 is connected to the coal mill.

[0050] The gas inside the coal mill is extracted through the vacuum pump 7 to realize gas circulation. At the same time, the vacuum pump 7 is started after the No. 1 solenoid valve 3, the No. 2 solenoid valve 4, the No. 3 solenoid valve 5 and the No. 4 solenoid valve 6 are actuated, so that most of the extracted gas is nitrogen, thereby realizing nitrogen recovery.

[0051] The oxygen consumption component 8 includes an air box 81, an air inlet pipe 82 and an air outlet pipe 83 arranged on the surface of the air box 81, a down pipe 84 arranged on the top of the air box 81, a No. 5 solenoid valve 85 arranged at the other end of the down pipe 84, an alcohol tank 86 arranged at the other end of the No. 5 solenoid valve 85, and a spark plug 87 arranged on the surface of the air box 81; wherein,

[0052] When the No. 5 solenoid valve 85 is opened, the alcohol in the alcohol tank 86 enters the air box 81, and the spark plug 87 is energized to ignite the alcohol.

[0053] The air inlet pipe 82 and the air outlet pipe 83 are connected to the surface of the air box 81 , the other end of the air outlet pipe 83 is connected to the No. 6 solenoid valve 9 , and the other end of the air inlet pipe 82 is connected to the air pump 7 .

[0054] Alcohol is ignited by the spark plug 87, and oxygen is consumed when the alcohol burns, thereby reducing the oxygen content inside the air box 81. At the same time, a small amount of water vapor is generated when the alcohol burns, which increases the humidity of the nitrogen, thereby better avoiding the occurrence of deflagration.

[0055] Usage process: Start the air extraction pump 7 to extract the gas inside the coal mill. The gas enters the inside of the air box 81 along the air inlet pipe 82. The fifth solenoid valve 85 is opened, and the alcohol inside the alcohol tank 86 enters the air box 81 along the liquid discharge pipe 84. The spark plug 87 ignites the alcohol. The burning of the alcohol consumes the oxygen inside the air box 81. The gas after consuming the oxygen is introduced into the pipeline connected to the first solenoid valve 3, the second solenoid valve 4, the third solenoid valve 5, and the fourth solenoid valve 6 through the air outlet pipe 83, realizing the recycling of nitrogen.

[0056] Example 3, referring to Figures 1 to 3 , which is the third embodiment of the present invention. Different from the previous embodiment, it further includes

[0057] The other end of the air outlet pipe 83 is connected to a sixth solenoid valve 9, and the other end of the sixth solenoid valve 9 is connected to a pressure reducing valve 2.

[0058] The sixth solenoid valve 9 is connected to the pressure reducing valve 2 through a pipeline. When the sixth solenoid valve 9 is opened, the nitrogen gas in the pressure reducing valve 2 enters the inside of the coal mill through the first solenoid valve 3, the second solenoid valve 4, the third solenoid valve 5, and the fourth solenoid valve 6, thereby filling nitrogen.

[0059] The upper end of the alcohol tank 86 is provided with a filling port, and the surface of the filling port is connected with a sealing cover.

[0060] The filling port facilitates the filling of alcohol, and the sealing cover can seal the alcohol tank 86, thereby avoiding the evaporation of alcohol.

[0061] The lower end of the liquid discharge pipe 84 is connected with an atomizing nozzle, and a liquid supply pump is arranged inside the alcohol tank 86.

[0062] The liquid supply pump can pump out the alcohol, and the alcohol introduced into the atomizing nozzle can be sprayed into a mist shape, thereby increasing the combustion efficiency.

[0063] Usage process: The liquid supply pump extracts the alcohol inside the alcohol tank 86, introduces the alcohol into the liquid discharge pipe 84, the alcohol is sprayed out from the atomizing nozzle, fills the inside of the air box 81, the spark plug 87 ignites and burns the alcohol, consuming the oxygen inside the air box 81. When the alcohol inside the alcohol tank 86 is lacking, open the sealing cover, pour alcohol into the filling port, and cover the sealing cover after filling.

[0064] Finally, it should be pointed out that the methods and devices described in detail above are only examples, and those skilled in the art can modify these examples in different ways as long as they do not depart from the scope of the present invention.

Claims

1. A method for preventing explosion and deflagration of a coal mill, characterized in that: including, a coal mill is connected with a nitrogen filling device; when the coal mill is running, the nitrogen filling device fills nitrogen into the coal mill, and the nitrogen filled into the coal mill occupies the oxygen proportion of the air in the coal mill.

2. The method for preventing explosion and combustion of a coal mill according to claim 1, characterized in that: According to the dynamic changes of the coal type blended in the coal mill, the coal quantity of the coal feeder and the operating parameters, the opening and closing frequency and the opening duration of the nitrogen filling device are regulated.

3. The method for preventing explosion and combustion of a coal mill according to claim 2, characterized in that: When the coal mill is running, different trigger logics are set through the coal quantity of the coal feeder, and the regular opening time of the solenoid valve is set in the trigger logic.

4. The method for preventing explosion and combustion of a coal mill according to claim 3, wherein: When the nitrogen filling device fills nitrogen into the coal mill, the nitrogen enters the coal mill from multiple directions.

5. The method for preventing explosion and deflagration of a coal mill according to claim 4, characterized in that: The nitrogen filling device consists of a nitrogen cylinder (1) and four solenoid valves; when the nitrogen filling device fills nitrogen into the coal mill, multiple groups of solenoid valves are opened synchronously; a pressure reducing valve (2) is connected between the nitrogen cylinder (1) and the solenoid valve.

6. An explosion-proof device, including the anti-explosion and combustion method of the coal mill according to any one of claims 1-5, characterized in that: an oxygen-consuming component (8), which includes a cavity, and the cavity is connected with a combustion mechanism; the combustion mechanism includes fuel; when the fuel burns in the cavity, the oxygen content in the gas entering the cavity is reduced.

7. The explosion-proof device according to claim 6, characterized in that: The four solenoid valves include a first solenoid valve (3), a second solenoid valve (4), a third solenoid valve (5) and a fourth solenoid valve (6). The first solenoid valve (3), the second solenoid valve (4), the third solenoid valve (5) and the fourth solenoid valve (6) are connected with the nitrogen cylinder (1) through the pressure reducing valve (2), and the other ends of the first solenoid valve (3), the second solenoid valve (4), the third solenoid valve (5) and the fourth solenoid valve (6) are connected with the coal mill through pipelines.

8. The explosion-proof device according to claim 7, characterized in that: The cavity is an air tank (81), and the combustion mechanism includes a spark plug (87), a lower liquid pipe (84), a fifth solenoid valve (85) and an alcohol tank (86). The surface of the air tank (81) is connected with an air inlet pipe (82) and an air outlet pipe (83). The other end of the air inlet pipe (82) is connected with an air extraction pump (7), and the other end of the air extraction pump (7) is connected with the coal mill.

9. The explosion-proof device according to claim 8, characterized in that: The other end of the air outlet pipe (83) is connected with a sixth solenoid valve (9), and the other end of the sixth solenoid valve (9) is connected with the pressure reducing valve (2).

10. The explosion-proof device according to claim 9, characterized in that: The lower end of the lower liquid pipe (84) is connected with an atomizing nozzle, and a liquid supply pump is arranged inside the alcohol tank (86).

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