JP7005230B2 - Crusher and its operation method - Google Patents

Description

The present invention relates to a crusher equipped with fire extinguishing equipment and an operation method thereof.

Solid fuels such as coal and biomass used in thermal power generation facilities are crushed into fine powder by a crusher and supplied to a combustion device such as a boiler. The crusher crushes solid fuel such as coal and biomass input from the coal supply pipe to the crushing table by chewing it between the crushing table and the crushing roller, and is crushed by the transport gas supplied from the outer periphery of the crushing table. The finely pulverized fuel is divided into smaller particle size by a classifier and transported to the combustion device.

Biomass fuel is attracting attention as one of the measures to reduce carbon dioxide emissions from boilers that use fossil fuels. Biomass fuel is supplied to a crusher in the form of pellets and crushed. For example, because it is easily ignited by static electricity, it may cause rapid combustion, and it is more likely that rapid combustion will occur than coal (pulverized coal). , When biomass is used as fuel, it is necessary to strengthen safety management.

In Patent Document 1, it is possible to install a fire extinguishing system that detects the pressure inside the mill and suppresses rapid combustion by injecting a fire extinguishing agent when the predetermined pressure at which rapid combustion may occur is exceeded. It has been disclosed.

JP-A-2010-2429999

However, although Patent Document 1 discloses that rapid combustion is detected by a large number of pressure sensors and injects a fire extinguishing agent, there is no description for selecting an appropriate installation location of the fire extinguishing agent.

Since rapid combustion propagates rapidly, it is easy to choose to install a large number of pressure detection locations and fire extinguishing agent installation locations, but this will increase costs. Therefore, it is desired to optimize the location of pressure detection and the location of fire extinguishing agent to reduce the number of excessive pressure detectors and fire extinguishing agents installed and the amount of fire extinguishing agent used. For example, if the distance from the location where rapid combustion occurs to the location where the fire extinguishing agent is ejected is too close, the fire extinguishing agent is sprayed after passing through the position of the extinguishing agent without the flame developing, and the flame spread is suppressed. May not be possible. On the other hand, if the distance is too long, a large amount of fire extinguishing agent is required because the flame develops greatly. For this reason, a large number of pressure sensors for detection and a large amount of fire extinguishing agent are often prepared, which is a factor that allows an increase in cost.

In this way, unless the occurrence of rapid combustion is accurately detected and the fire extinguishing agent is injected at the appropriate location and at the appropriate timing for the position where rapid combustion occurs, rapid combustion cannot be suppressed, and each device of the crusher May be damaged.

The present invention has been made in view of such circumstances, and provides a crusher capable of accurately detecting the occurrence of rapid combustion and injecting a fire extinguishing agent at an appropriate timing, and an operation method thereof. With the goal.

In order to solve the above problems, the crusher of the present invention and its operation method adopt the following means.
That is, the crusher according to the present invention is a crusher that crushes solid fuel into fine powdery solid fuel, and is supplied from the fuel supply pipe for supplying the solid fuel before crushing and the fuel supply pipe. A rotary table in which the solid fuel is guided to the upper surface and rotates around the central axis, a crushing roller for crushing the solid fuel between the rotary table arranged facing the rotary table and the upper surface of the rotary table, and the rotation. A transport gas supply pipe that supplies transport gas to the space vertically below the table, a classifier that classifies the crushed solid fuel that is wound up by the transport gas guided from the transport gas supply pipe, and the classifier. It is provided with a fine powder fuel supply pipe that guides the fine powdered solid fuel classified in A pressure sensor for detecting the rise and a fire extinguishing agent ejection part for injecting a fire extinguishing agent based on the detection result of the pressure sensor are provided , and the space where the fire may spread due to the rapid combustion of the solid fuel is provided. A fire extinguishing agent ejection portion for injecting a fire extinguishing agent based on the detection result of the pressure sensor is provided, and the space where rapid combustion of the solid fuel may occur is vertically above the rotary table and of the classifier. It is characterized by being an upper space on the upstream side .

The crusher has spaces with different atmospheric conditions when biomass fuel is used as the solid fuel. There is space that can ignite and cause rapid combustion. Since the upper space above the rotary table and upstream of the classifier has a large amount of biomass fuel after crushing, there is a high possibility that it will ignite and cause rapid combustion compared to other spaces. Therefore, it was decided to install a pressure sensor to detect the rapid combustion of biomass fuel and a fire extinguishing agent ejection part in this upper space to extinguish the fire at an appropriate timing.
In addition, in the classification space on the downstream side of the classification machine and on the upstream side of the fuel supply pipe, there is a large amount of biomass fuel that has become fine powder after classification, and the transport gas, which is dominated by air, is heated. It is more likely that it will ignite and cause rapid combustion compared to other spaces. Therefore, it was decided to install a pressure sensor to detect the rapid combustion of biomass fuel and a fire extinguishing agent ejection part in this classification space to extinguish the fire at an appropriate timing.
As described above, by selecting at least the upper space and the classification space as spaces that are more likely to ignite and cause rapid combustion than other spaces, and by setting the pressure sensor and fire extinguishing agent ejection part here, It was decided to arrange pressure sensors and fire extinguishing agent ejection parts in an appropriate space to suppress rapid combustion, and to provide an appropriate number of pressure sensors and fire extinguishing agent ejection parts. As a result, rapid combustion can be effectively suppressed by accurately detecting rapid combustion and injecting a fire extinguishing agent at an appropriate timing.
The solid fuel is, for example, a biomass fuel.

The space where rapid combustion of the solid fuel may occur is preferably a classification space on the downstream side of the classifier and on the upstream side of the fine powder fuel supply pipe.

Further, the space where the rapid combustion of the solid fuel may occur is preferably a lower space located on the vertically lower side of the rotary table.

The lower space is vertically below the rotary table, and the biomass fuel crushed on the rotary table is wound up by the transport gas, so that the abundance of the biomass fuel is smaller than that in the upper space. However, there is not a small amount of biomass fuel, and the lower space is supplied with transport gas and has a large amount of air, and when the transport gas is heated, there is a higher possibility of ignition than in other spaces. It was decided to provide a fire extinguishing agent ejection part. This makes it possible to further suppress rapid combustion.
A pressure sensor for detecting rapid combustion may be provided in the lower space, but since the possibility of ignition is lower than in the upper space and the classification space, the pressure sensor is omitted and the upper space and the classification space close to the lower space are used. You may use the signal of the pressure sensor of.

Further, in the crusher of the present invention, the fire extinguishing agent ejection portions are provided as a pair at the facing positions of the lower space and / or the facing positions of the upper space across the central axis. It is a feature.

Since the fire extinguishing agent ejection part is provided so as to be paired at the opposite positions in the lower space and / or the opposite positions in the upper space across the central axis, the lower space and / or the upper space The fire extinguishing agent can be sprayed over a wide area with less bias.

Further, in the crusher of the present invention, the space where the fire may spread due to the rapid combustion of the solid fuel is the fuel supply pipe and / or the transport gas supply pipe and / or the fine powder fuel supply pipe. It is characterized by being said to be.

Unlike the space where ignition occurs and rapid combustion occurs, there is a space where rapid combustion may spread. By providing a fire extinguishing agent ejection part in the fuel supply pipe and / or the transport gas supply pipe and / or the fine powder fuel supply pipe, it is possible to suppress the spread of rapid combustion generated in the upper space or the classification space. ..

Further, in the crusher of the present invention, the fire extinguishing agent ejection portion is provided at a position where the fire extinguishing agent is injected before and after the flame propagation of rapid combustion arrives.

By providing the extinguishing agent ejection portion at a position where the extinguishing agent is injected before and after the flame propagation of rapid combustion arrives, the extinguishing agent can be injected at an appropriate timing.

Further, in the crusher of the present invention, a rotary valve is provided in the middle of the fuel supply pipe, and the fire extinguishing agent ejection portion extinguishes a fire in the fuel supply pipe between the upper space vertically below the rotary valve. It is characterized in that it is provided at a position where the agent is sprayed.

Even if there is a gap in the sliding part of the rotating part of the rotary valve, the fire extinguishing agent ejection part can surely prevent the spread of fire, and the fire extinguishing agent can be mixed into the rotary valve to suppress the occurrence of blockage. can.

Further, in the operation method of the crusher of the present invention, the pre-crushing fuel supply pipe for supplying the biomass fuel before crushing and the biomass fuel supplied from the pre-crushing fuel supply pipe are guided to the upper surface and rotate around the central axis. A crushing roller for crushing biomass fuel between the rotary table facing the rotary table and the upper surface of the rotary table, and an air supply for supplying air to a lower space located below the rotary table. A pipe, a classifier that classifies the crushed biomass fuel wound up by the air guided from the air supply pipe, and a fine powder fuel supply pipe that guides the classified biomass fuel classified by the classifier to the outside. In the operation method of the crusher provided with the above, there is a possibility that the space inside the crusher where the rapid combustion of the solid fuel may occur and the rapid combustion of the solid fuel may cause the spread of fire. Based on the pressure sensor that detects the pressure rise due to the rapid combustion of the solid fuel and the detection result of the pressure sensor in the space where the rapid combustion of the solid fuel may occur. A fire extinguishing agent ejection part that injects a fire extinguishing agent based on the detection result of the pressure sensor is provided in a space where a fire spread may occur due to rapid combustion of the solid fuel. The space where rapid combustion of the solid fuel may occur is characterized in that it is an upper space vertically above the rotary table and upstream of the classifier.

Since the pressure sensor and the fire extinguishing agent ejection part are provided in an appropriate space, the rapid combustion can be effectively suppressed by accurately detecting the rapid combustion and injecting the extinguishing agent at an appropriate timing.

It is a schematic block diagram which showed the boiler equipment provided with the crusher which concerns on one Embodiment of this invention. It is a vertical sectional view which showed the crusher which concerns on one Embodiment of this invention. It is a perspective view which showed the fire extinguishing agent ejection part arranged in the upper space and the lower space. It is a graph which showed the spread propagation when the fire extinguishing agent ejection part was provided at an appropriate position. It is a graph which showed the spread propagation when the extinguishing agent ejection part was provided at the position closer to the place where rapid combustion occurred than the proper position. It is a graph which showed the spread propagation when the extinguishing agent ejection part was provided at the position farther from the place where rapid combustion occurred than the proper position.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a boiler facility 1 provided with a crusher according to the present embodiment. In the present embodiment, the upper direction indicates the vertical upper direction, and the lower direction indicates the vertical lower direction.
In the present embodiment, the boiler equipment 1 is provided with a crusher 5 that uses, for example, biomass fuel as solid fuel and crushes the biomass fuel supplied to the boiler main body 3. The crusher 5 may be in the form of crushing only the biomass fuel, or may be in the form of crushing the biomass fuel together with coal. Here, the biomass fuel is a renewable organic resource derived from living organisms, and is, for example, thinned wood, waste wood, drifting wood, grass, waste, sludge, tires, and recycled fuel (pellets and pellets) made from these. Chips), etc., and are not limited to those presented here. Since biomass fuel takes in carbon dioxide during the growth process of biomass, it is considered to be carbon-neutral, which does not emit carbon dioxide, which is a global warming gas, and its use is being studied in various ways.

A fine powder fuel supply pipe 7 is connected to the crusher 5, and the fine powder fuel crushed by the crusher 5 is guided to the burner 9 through the fine powder fuel supply pipe 7 together with hot air as a transport gas. ing.
The biomass fuel stored in the biomass silo 11 is guided to the crusher 5 via the bunker 13.
A hot air supply pipe (conveyed gas supply pipe) 15 is connected to the crusher 5. The hot air supply pipe 15 is connected to the primary ventilator 17, and the air preheated by the air preheater 19 and the air bypassing the air preheater 19 are mixed to guide the temperature-controlled air. It has become like. Further, a part of the exhaust gas that has passed through the electrostatic precipitator 23 is guided to the hot air supply pipe 15 via the gas recirculation ventilator 21. Therefore, the air-fuel mixture whose temperature is adjusted by the air preheater 19 and whose oxygen concentration is adjusted by the exhaust gas is guided to the crusher 5 via the hot air supply pipe 15.

A flame is formed by the burner 9 in the furnace in the boiler main body 3, and steam is generated by a heat exchanger (not shown) in the boiler main body 3. The generated steam is guided to a steam turbine (not shown) to generate electricity.

The exhaust gas discharged from the boiler main body 3 is denitrified by the denitration device 25, then heated by the air preheater 19 with the air guided from the primary ventilator 17, and then guided to the electrostatic precipitator 23. The exhaust gas is dedusted by the electrostatic precipitator 23 and then guided to the desulfurization device 29 via the induced ventilator 27. On the upstream side of the attracting ventilator 27, a part of the exhaust gas may be extracted and guided to the hot air supply pipe 15 via the gas recirculation ventilator 21.
The exhaust gas guided from the induction ventilator 27 is desulfurized by the desulfurization device 29 and then guided to the chimney 31 and released into the atmosphere.

FIG. 2 shows the details of the crusher 5 shown in FIG. The crusher 5 is a vertical mill and crushes solid materials such as coal fuel and biomass fuel.

The housing 41 of the crusher 5 has a vertical cylindrical hollow shape, and a fuel supply pipe 43 is attached to the central portion of the ceiling portion 42. The fuel supply pipe 43 supplies pellet-shaped biomass fuel derived from the biomass silo 11 (see FIG. 1) from the bunker 13 into the housing 41 via the fuel supply machine 72 and the rotary valve 74. It is arranged at the center position of the housing 41 along the vertical direction (vertical direction), and the lower end portion extends to the inside of the housing 41.

In the case of coal fuel, the fuel supply machine 72 is called a coal feeder, and delivers fuel in a predetermined amount of supply. For example, the fuel supply machine 72 is a belt conveyor type.
A bunker 13 is connected above the fuel supply machine 72 via a down spout 71. When the biomass fuel is used in the bunker 13, a bellet-shaped biomass fuel is stored, and the down spout 71 is a steel pipe portion extending in the vertical direction, and the fuel is held in a laminated state inside. In the case of coal fuel, the coal fuel laminated in the down spout 71 ensures a sealing property in which the pressurized gas containing fine powder on the crusher 5 side does not flow back to the bunker 13 side. On the other hand, when the biomass fuel is used, there is a gap between the beret-shaped biomass fuels, and the sealing property by the fuel layer in the down spout 71 is insufficient as compared with the coal fuel. Therefore, when using biomass fuel, a rotary valve 74 is provided in the middle of the fuel supply pipe 43.

The rotary valve 74 includes a rotating portion provided in the valve housing with a plurality of chambers partitioned in the direction of rotation. Since each room formed in the rotating part is independent, the flow of pressurized gas from the lower side to the upper side of the fuel supply pipe 43 can be sealed, and the pressurized gas containing fine powder on the crusher 5 side moves to the bunker 13 side. It is designed to ensure the sealing property that does not flow back.
Further, in the rotary valve 74, a seal air pipe 74a is connected via a seal air valve 74a1 to a rotary valve 74 having a gap in the sliding portion 74b between the valve housing and the rotating portion. The seal air supplied from the seal air pipe 74a seals the gap between the sliding portion 74b between the valve housing and the rotating portion.

A gantry 44 is installed in the lower part of the housing 41, and a crushing table (rotary table) 45 is rotatably arranged on the gantry 44. The lower end of the fuel supply pipe 43 is arranged so as to face the center of the crushing table 45. The fuel supply pipe 43 supplies the biomass fuel from the upper side to the lower side as shown by the arrow A0.

The crushing table 45 is rotatable around the central axis in the vertical direction (vertical direction) and is driven by a drive device (not shown). The upper surface of the crushing table 45 may have an inclined shape such that the central portion is high and the upper surface is lowered toward the outside, and the outer peripheral portion may be curved upward.

Above the crushing table 15, a plurality of crushing rollers 46 are arranged so as to face each other. Each crushing roller 46 is arranged above the outer peripheral portion of the crushing table 45 at equal intervals in the circumferential direction (note that only one crushing roller 46 and its peripheral equipment are shown in FIG. 2 as a representative. ). The crushing roller 46 can swing up and down, and is supported so as to be able to approach and separate from the upper surface of the crushing table 45. When the crushing table 45 rotates with the outer peripheral surface in contact with the upper surface of the crushing table 45, the crushing roller 46 receives rotational force from the crushing table 45 and rotates around. When the biomass fuel is supplied from the fuel supply pipe 43, the biomass fuel is pressed between the crushing roller 46 and the crushing table 45 to be crushed.

A hot air supply pipe 15 (see FIG. 1) is connected to the lower part of the housing 41. The hot air supplied by the hot air supply pipe 15 is guided into the housing 41 as shown by the arrow A1 and is supplied to the lower space S1 located below the crushing table 45. In FIG. 2, a confluence portion 15a for mixing hot air and cold air is shown on the upstream side (right side in FIG. 2) of the hot air supply pipe 15 in the flow direction of hot air. The air is supplied from the primary ventilator 17, of which the preheated air heated by the air preheater 19 and the cold air supplied by bypassing the air preheater 19 are supplied, and the preheated air and the cold air meet at the confluence 15a. The hot air is controlled to reach a temperature within a predetermined range. Further, a part of the exhaust gas that has passed through the electrostatic precipitator 23 is guided through the gas recirculation ventilator 21, and the oxygen concentration of the hot air is adjusted by the exhaust gas.

The space where ignition may occur and rapid combustion may occur will be described. In the present embodiment, the lower space S1 corresponds to the upper space S2 and the classification space S3.
A fire extinguishing agent ejection portion 60 for injecting a fire extinguishing agent toward the inside of the lower space S1 is provided on the side wall portion of the housing 41 forming the lower space S1. In the present embodiment shown in FIG. 2, for example, two fire extinguishing agent ejection portions 60 are provided, and as shown in FIG. 3, for example, they are paired with each other across the central axis of the housing 41. It is provided. However, the number of fire extinguishing agent ejection portions 60 is not limited to two and is determined by the size of the lower space S1.

A pressure sensor 61 may be provided in the lower space S1 at a position indicated by a cross. However, the pressure sensor 61 in the lower space S1 may be omitted (described later).

A rotary separator (classifier) 53 is provided on the upper portion of the housing 41. The rotary separator 53 is arranged so as to surround the fuel supply pipe 43, and rotates around the fuel supply pipe 43. As the rotary separator 53 rotates, a plurality of blades 53a attached to the outer peripheral side thereof travel in the circumferential direction. The fine powder of the biomass fuel crushed by the crushing table 45 and the crushing roller 46 is wound upward by the flow of hot air (see arrow A2) rising from the lower space S1 through the outer peripheral side of the crushing table 45. Of the fine powder that has been rolled up, the fine powder having a relatively large diameter is knocked down by the blade 53a, returned to the crushing table 45, and crushed again. As a result, the rotary separator 53 classifies the fine powder according to the size of the fine powder, and the fine powder having a predetermined diameter or less is conveyed from the fine powder fuel supply pipe 7 together with hot air and carried out.

An upper space S2 is formed between the upstream side of the rotary separator 53 (lower side of the rotary separator 53) and the upper side of the crushing table 45. A fire extinguishing agent ejection portion 60 for injecting a fire extinguishing agent toward the inside of the upper space S2 is provided on the side wall portion of the housing 41 forming the upper space S2. In FIG. 2, for example, two fire extinguishing agent ejection portions 60 are provided, and as shown in FIG. 3, for example, they are provided so as to face each other with the central axis of the housing 41 interposed therebetween. The number of fire extinguishing agent ejection portions 60 is not limited to two. However, the number of fire extinguishing agent ejection portions 60 is determined by the size of the upper space S2.
When, for example, two fire extinguishing agent injection portions 60 are provided, they are provided so as to face each other across the central axis of the housing 41, but the fire extinguishing agent injection portion 60 in the upper space S2 and the lower space are provided. The fire extinguishing agent injection unit 60 of S1 does not have to be at the same position in the circumferential direction of the housing 41, and may be displaced from each other in the circumferential direction. Therefore, the fire extinguishing agent can be sprayed with less bias over a wide area of both the upper space S2 and the lower space S1.

In the upper space S2, a pressure sensor 61 for detecting rapid combustion is provided at a position indicated by a cross. The number of pressure sensors 61 is determined by the volume in the upper space S2, and is set to, for example, two in the present embodiment shown in FIG. The number of pressure sensors 61 is not limited to two.

A fine fuel supply pipe 7 is connected to the ceiling portion 42. The fine powder fuel supply pipe 7 discharges the fine powder of the biomass fuel after being classified by the rotary separator 53 together with hot air as shown by the arrow A3, and leads to the boiler main body 3 (see FIG. 1). The classification space S3 is formed in the space on the downstream side of the rotary separator 53 and on the upstream side of the fine powder fuel supply pipe 7, that is, in the inner space surrounded by the blade 53a of the rotary separator 53.

The ceiling portion 42 forming the classification space S3 is provided with a fire extinguishing agent ejection portion 60 for injecting a fire extinguishing agent toward the inside of the classification space S3. In FIG. 2, the number of fire extinguishing agent ejection portions 60 is one. However, the number of fire extinguishing agent ejection portions 60 is determined by the size of the classification space S3.

In the classification space S3, a pressure sensor 61 for detecting rapid combustion is provided at a position indicated by a cross. The number of pressure sensors 61 is determined by the volume in the classification space S3, and is set to one, for example, in the present embodiment shown in FIG. The number of pressure sensors 61 is not limited to one.

As described above, hot air is supplied from the hot air supply pipe 15 to the lower space S1, passes through the upper space S2, passes through the classification space S3, and flows to the fine fuel supply pipe 7. The crushed fuel between the crushing roller 46 and the crushing table 45 becomes fine powder, is wound up by hot air, is classified through the rotary separator 53, and then passes through the fine powder fuel supply pipe 7 to the burner 9 of the boiler main body 3. Be guided. Therefore, there is a space affected by rapid combustion other than the lower space S1, the upper space S2, and the classification space S3.

The fire extinguishing agent ejected from the fire extinguishing agent ejection portion 60 provided in the lower space S1, the upper space S2 and the classification space S3 may be of any type as long as it has a fire extinguishing function, but for example, powder (sodium hydrogen carbonate: generally baking soda). , Etc.) are used.

The pressure sensors 61 provided in the lower space S1, the upper space S2, and the classification space S3 detect a pressure increase when the biomass fuel ignites in the crusher 5 and rapid combustion occurs. The output of the pressure sensor 61 is transmitted to a control unit (not shown). The control unit determines the occurrence of rapid combustion from the pressure value transmitted from the pressure sensor 61, and controls the operation of the fire extinguishing agent ejection unit 60 provided in the lower space S1, the upper space S2, and the classification space S3 based on the result. do.

For example, the control unit determines that rapid combustion has occurred when any of the pressure sensors 61 provided in the lower space S1, the upper space S2, and the classification space S3 exceeds a predetermined threshold value. Alternatively, two of the three pressure sensors 61 composed of two pressure sensors 61 of the pressure sensors 61 provided in the upper space S2 and one of the pressure sensors 61 of the pressure sensors 61 provided in the classification space S3. When one of the sensors exceeds a predetermined threshold value, it may be determined that rapid combustion has occurred and erroneous determination may be suppressed. When it is determined by the control unit that rapid combustion has occurred, the fire extinguishing agent provided in the lower space S1, the upper space S2, and the classification space S3 is controlled to be ejected from the fire extinguishing agent ejection unit 60 substantially at the same time.

The threshold value for determining rapid combustion is preferably changed according to the operating pressure of the crusher 5. For example, when the operating pressure of the crusher 5 is set to the minimum operating pressure (for example, atmospheric pressure) as in the stop operation when the boiler main body 3 is stopped, a predetermined pressure (for example, 500 mAq or more and 1000 mAq or less) is higher than the minimum operating pressure. ) When the above, the occurrence of rapid combustion is judged. Further, when the maximum operating pressure is set as when the rotary separator 53 is rotated at high speed to clean the rotary separator 53, the predetermined pressure (for example, 200 mAq or more and 500 mAq or less) or more is set higher than the maximum operating pressure. If this happens, determine the occurrence of rapid combustion.

The control unit is composed of, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a computer-readable storage medium, and the like. As an example, a series of processes for realizing various functions are stored in a storage medium or the like in the form of a program, and the CPU reads this program into a RAM or the like to execute information processing / arithmetic processing. As a result, various functions are realized. The program is installed in a ROM or other storage medium in advance, is provided in a state of being stored in a computer-readable storage medium, or is distributed via a wired or wireless communication means. Etc. may be applied. The computer-readable storage medium is a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like.

The reason for installing the fire extinguishing agent ejection part 60 in the lower space S1, the upper space S2, and the classification space S3 will be described.
The reason why the fire extinguishing agent ejection part 60 is installed in the upper space S2 and the classification space S3 is that a large amount of biomass fuel after crushing exists in the upper space S2 due to the upper part of the crushing table 45, and the classification space S3. Then, when there are a lot of finely divided biomass fuel and the hot air that is the transport gas is heated, it is easier to ignite than other spaces, and the volatile matter from the biomass fuel and foreign matter. This is because sparks are generated due to contamination, and it is a space that is easier to ignite than other spaces, and it is a space that exists as fine powder and has a large surface area and is easier to ignite than other spaces. Therefore, a pressure sensor 61 is also installed in such a space so that the fire can be extinguished at an appropriate timing.

On the other hand, the lower space S1 is below the crushing table 45, and the biomass fuel crushed on the crushing table 45 is wound up by the hot air supplied to the lower space S1. The abundance is small. However, there is not a small amount of fine powder of biomass fuel, and since it is a space to which a large amount of hot air is supplied, there is a risk of ignition compared to other spaces. Therefore, the fire extinguishing agent ejection portion 60 is provided. However, the pressure sensor 61 may be omitted, and the signal of the pressure sensor in the upper space S2 close to the lower space S1 or the classification space S3 may be used.

Next, unlike the space where ignition occurs and rapid combustion occurs, a space where ignition occurs in another space and rapid combustion may spread will be described. In this embodiment, the fuel supply pipe 43, the hot air supply pipe 15, and the fine powder fuel supply pipe 7 correspond to each other.
The fire extinguishing agent ejection portion 60 is also provided in the fuel supply pipe 43, the hot air supply pipe 15, and the fine powder fuel supply pipe 7. Each fire extinguishing agent ejection unit 60 is controlled by a control unit in the same manner as the above-mentioned fire extinguishing agent ejection unit 60. These fire extinguishing agent ejection portions 60 prevent the spread of rapid combustion.

Here, the rotary valve 74 provided in the middle of the fuel supply pipe 43 has a gap formed in the sliding portion 74b with the rotating portion in the valve housing, so that the seal air is sealed with the seal air supplied from the seal air pipe 74a. conduct. Therefore, since the fire spread of rapid combustion in the fuel supply pipe 43 may pass through the rotary valve 74 and spread, a fire extinguishing agent ejection portion 60 is provided between the fire extinguishing agent ejection portion 60 and the upper space S2 on the lower side of the rotary valve 47. Is preferable. As a result, it is possible to further prevent the spread of fire from another space to the upstream side, suppress the increase in cleaning work by mixing the fire extinguishing agent into the rotary valve 74, and suppress the occurrence of blockage due to the fire extinguishing agent. Therefore, it is preferable.

On the other hand, when a structure having no gap in the sliding portion (complete insulation structure) is used as the structure of the rotary valve 74, the possibility of fire spreading is reduced, so that the fire extinguishing agent ejection portion 60 of the fuel supply pipe 43 is omitted. You may.

Further, the fuel supply pipe 43, the hot air supply pipe 15, and the fine powder fuel supply pipe 7 need to be provided with a fire extinguishing agent ejection part 60 because there is a risk of fire spreading, but since the possibility of ignition is low, the pressure sensor 61 is used. It is not necessary to provide it, and the signal of the pressure sensor in the upper space S2 and the classification space S3 near the fire spread space should be used so that the fire extinguishing agent is ejected at an appropriate timing in consideration of the propagation time of rapid combustion. Is preferable.

The location of the fire extinguishing agent ejection unit 60 is set in consideration of the propagation time of rapid combustion. Specifically, as shown in FIG. 4A, when rapid combustion occurs at time t0, the fire extinguishing agent is installed at a position where the fire extinguishing agent can be injected before and after the flame propagation of rapid combustion arrives. In FIG. 4A, the horizontal axis shows the distance (proportional to time), and the vertical axis shows the pressure increase due to the spread of fire and the amount of fire extinguishing agent ejected. As rapid combustion occurs and time passes, the spread of fire spreads to a distant distance and the pressure rises. When it is determined that rapid combustion has occurred, the fire extinguishing agent is ejected from the extinguishing agent ejection unit 60 by the control unit, but as shown by the alternate long and short dash line in FIG. Effective fire extinguishing is performed by injecting a fire extinguishing agent over the entire area. That is, if the fire extinguishing agent is not sprayed, the pressure rise due to the spread of fire as shown by the solid line can be extinguished by suppressing the pressure rise as shown by the broken line.

On the other hand, when the installation position of the fire extinguishing agent ejection part 60 is closer to the place where the rapid combustion occurs than the proper position, the extinguishing agent is injected from the time t1'to t2' as shown in FIG. 4B. Since the extinguishing agent is ejected too quickly for the spread of the flame, the extinguishing agent is ejected after passing through the extinguishing agent ejection portion 60 without developing the flame due to the spread of fire, effectively suppressing the spread of fire. After spraying the fire extinguisher, the flame develops and spreads, and the pressure rises.

Further, when the installation position of the fire extinguishing agent ejection part 60 is farther from the place where the rapid combustion occurs than the proper position, the extinguishing agent is injected from the time t1 ″ to t2 ″ as shown in FIG. The fire extinguishing agent will be ejected after it spreads, and it will be necessary to add the fire extinguishing agent in a state where the fire extinguishing is not in time or the fire spread propagation is wider than at the time of design. An agent is required and rapid combustion cannot be suppressed efficiently. Therefore, it becomes a factor of cost increase.

The crusher 5 having the above configuration operates as follows.
When the biomass fuel is charged from the fuel supply pipe 43 toward the center of the crushing table 45 (see arrow A0), the centrifugal force due to the rotation of the crushing table 45 guides the biomass fuel to the outer peripheral side of the crushing table 45 and crushes it. It is sandwiched between the roller 46 and crushed. The crushed biomass fuel is wound upward by the hot air guided from the hot air supply pipe 15 (see arrow A2) and guided to the rotary separator 53. In the rotary separator 53, the fine powder having a relatively large diameter is knocked down by the blade 53a and returned to the crushing table 45. The fine powder after classification that has passed through the blade 53a is guided to the fine powder fuel supply pipe 7 together with hot air, and is supplied to the burner 9 (see FIG. 1) of the boiler main body 3.

When the biomass fuel ignites and rapid combustion occurs during the operation or stop operation of the crusher 5 as described above, the control unit rapidly operates according to the detection value of the pressure sensor 61 appropriately provided in each space. The occurrence of combustion is determined, and the fire extinguishing agent is injected at an appropriate timing from each fire extinguishing agent ejection unit 60 appropriately provided in each space.

According to this embodiment, the following effects are exhibited.
The upper space S2 above the crushing table 45 and on the upstream side of the rotary separator 53 (lower side of the rotary separator 53) has a large amount of biomass fuel after crushing, so that it ignites as compared with other spaces. Rapid combustion is likely to occur. Therefore, it was decided to install a pressure sensor 61 for detecting the rapid combustion of biomass fuel and a fire extinguishing agent ejection unit 60 in the upper space S2 to extinguish the fire at an appropriate timing.
Further, the classification space S3 on the downstream side of the rotary separator 53 and on the upstream side of the fine powder fuel supply pipe 7 contains a large amount of biomass fuel that has become fine powder after classification, and has a large surface area, so that it is another space. It is more likely to ignite and cause rapid combustion. Therefore, it was decided to install a pressure sensor 61 for detecting the rapid combustion of biomass fuel and a fire extinguishing agent ejection unit 60 in the classification space S3 to extinguish the fire at an appropriate timing.
As described above, by setting the pressure sensor 61 and the fire extinguishing agent ejection unit 60 in at least the upper space S2 and the classification space S3, the pressure sensor 61 and the fire extinguishing agent ejection unit 60 are provided in an appropriate space for suppressing rapid combustion. It was decided to arrange and provide an appropriate number of pressure sensors 61 and fire extinguishing agent ejection parts 60. As a result, rapid combustion can be suppressed by accurately detecting rapid combustion and injecting a fire extinguishing agent at an appropriate timing.

Further, since the fire extinguishing agent ejection portion 60 is provided so as to be paired at the positions facing the lower space S1 and / or the upper space S2 with the central axis in between, the lower space S1 and / or the upper space is provided. The fire extinguishing agent can be sprayed with less bias over a wide area of S2.

Since the lower space S1 is below the crushing table 45 and the biomass fuel crushed on the crushing table 45 is wound up by hot air, the abundance of the biomass fuel is smaller than that in the upper space S2. However, since there is not a small amount of biomass fuel and there is a high possibility that the lower space S1 will be ignited by hot air, it was decided to provide a fire extinguishing agent ejection portion 60. This makes it possible to further suppress rapid combustion.

For the space where the fire spreads, the fuel supply pipe 43, the hot air supply pipe 15, and the fine powder fuel supply pipe 7 are provided with the fire extinguishing agent ejection part 60 at an appropriate position in consideration of the propagation time of rapid combustion, thereby providing an upper space. It is possible to suppress the spread of rapid combustion generated in S2 and the classification space S3.
Further, when selecting the rotary valve, even in the case of a structure in which a gap is provided in the sliding portion 74b provided in the rotating portion, the fire extinguishing agent ejection portion 60 is provided between the upper space S2 on the lower side of the rotary valve 60. Therefore, the spread of fire can be prevented more reliably.

By providing the fire extinguishing agent ejection unit 60 at a position where the extinguishing agent is injected before and after the flame propagation of rapid combustion arrives, the fire extinguishing agent can be injected at an appropriate timing.

Although the above-described embodiment has been described as a crusher 5 that exclusively crushes biomass fuel, the present invention is not limited to this, and a crusher that crushes biomass fuel together with coal, or coal and biomass fuel can be used. It can also be used for crushers that are switched and used.

Although it was decided to provide the fire extinguishing agent ejection part 60 in the fuel supply pipe 43, the hot air supply pipe 15, and the fine powder fuel supply pipe 7, the fire extinguishing agent ejection part 60 should be provided in any one or two of them. May be.
Further, in the embodiment of the present invention, the solid fuel crushed by the crusher is described as the biomass fuel, but the solid fuel to be crushed is not limited to the biomass fuel and may be coal or the like having high ignitability. Hydrocarbon-containing fossil solid fuels such as coal may be used, a mixture of coal and biomass fuel may be crushed, or a mixture of coal and biomass fuel may be switched and crushed. Is possible.

1 Boiler equipment 3 Boiler body 5 Crusher 7 Fine fuel supply pipe 9 Burner 11 Biomass silo 13 Banker 15 Hot air supply pipe (conveyed gas supply pipe)
17 Primary ventilator 19 Air preheater 21 Gas recirculation ventilator 23 Electrodust collector 25 Denitration device 27 Induction ventilator 29 Desulfurization device 31 Chimney 41 Housing 42 Ceiling 43 Fuel supply pipe 44 Stand 45 Crushing table (rotary table)
46 Crushing roller 53 Rotary separator (classifier)
60 Fire extinguishing agent ejection part 61 Pressure sensor 71 Down spout 72 Fuel supply machine 74 Rotary valve S1 Lower space S2 Upper space S3 Classification space

Claims (9)

A crusher that crushes solid fuel into fine powdered solid fuel.
The fuel supply pipe that supplies the solid fuel before crushing,
A rotary table in which the solid fuel supplied from the fuel supply pipe is guided to the upper surface and rotates around the central axis.
A crushing roller arranged to face the rotary table and crushing the solid fuel between the rotary table and the upper surface thereof.
A transport gas supply pipe that supplies transport gas to the space vertically below the rotary table, and
A classifier for classifying the crushed solid fuel wound up by the transport gas guided from the transport gas supply pipe, and a classifier.
A fine powder fuel supply pipe that guides the fine powdered solid fuel classified by the classifier to the outside,
Equipped with
The internal space of the crusher includes a space where rapid combustion of the solid fuel may occur and a space where rapid combustion of the solid fuel may cause fire spread.
A pressure sensor that detects a pressure increase due to rapid combustion of the solid fuel and a fire extinguishing agent that injects a fire extinguishing agent based on the detection result of the pressure sensor in a space where rapid combustion of the solid fuel may occur. A part is provided ,
A fire extinguishing agent ejection part for injecting a fire extinguishing agent based on the detection result of the pressure sensor is provided in a space where fire spread may occur due to rapid combustion of the solid fuel.
A crusher characterized in that the space where rapid combustion of the solid fuel may occur is an upper space vertically above the rotary table and upstream of the classifier . The space according to claim 1 , wherein the space where rapid combustion of the solid fuel may occur is a classification space on the downstream side of the classifier and on the upstream side of the pulverized fuel supply pipe. Crusher. The crusher according to claim 1 or 2, wherein the space where rapid combustion of the solid fuel may occur is a lower space located vertically below the rotary table. 3. The crusher described in any. The space where the fire may spread due to the rapid combustion of the solid fuel is the fuel supply pipe and / or the transport gas supply pipe and / or the fine powder fuel supply pipe . Item 6. The crusher according to any one of Items 1 to 3. The crusher according to any one of claims 1 to 4, wherein the fire extinguishing agent ejection unit is provided at a position where the fire extinguishing agent is injected before and after the flame propagation of rapid combustion arrives. A rotary valve is provided in the middle of the fuel supply pipe.
The sixth aspect of claim 6 is characterized in that the fire extinguishing agent ejection portion is provided at a position where the fire extinguishing agent is injected into the fuel supply pipe between the above space vertically below the rotary valve. Crusher. The crusher according to any one of claims 1 to 7, wherein the solid fuel is a biomass fuel. It is an operation method of a crusher that crushes solid fuel into fine powder solid fuel.
The fuel supply pipe that supplies the solid fuel before crushing,
A rotary table in which the solid fuel supplied from the fuel supply pipe is guided to the upper surface and rotates around the central axis.
A crushing roller arranged to face the rotary table and crushing the solid fuel between the rotary table and the upper surface thereof.
A transport gas supply pipe that supplies transport gas to the lower space located vertically below the rotary table, and
A classifier for classifying the crushed solid fuel wound up by the transport gas guided from the transport gas supply pipe, and a classifier.
A fine fuel supply pipe that guides the solid fuel after classification by the classifier to the outside, and
It is an operation method of a crusher equipped with
Among the internal spaces of the crusher, a space in which the rapid combustion of the solid fuel may occur and a space in which the rapid combustion of the solid fuel may cause the spread of fire are selected.
A pressure sensor that detects a pressure increase due to rapid combustion of the solid fuel and a fire extinguishing agent that injects a fire extinguishing agent based on the detection result of the pressure sensor in a space where rapid combustion of the solid fuel may occur. With a part
A fire extinguishing agent ejection part for injecting a fire extinguishing agent based on the detection result of the pressure sensor is provided in a space where fire spread may occur due to rapid combustion of the solid fuel.
A method for operating a crusher , wherein the space where rapid combustion of the solid fuel may occur is an upper space vertically above the rotary table and upstream of the classifier .

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