System and method for purging crushed material

Abstract

A crushing apparatus for supplying a crushed material crushed in the main body of the crushing apparatus to a supply destination through at least a discharge pipe, the crushing apparatus comprising a purging fluid supply part which is provided separately from the main body and supplies a predetermined purging fluid to the discharge pipe when the operation of the main body is stopped.

Description

[Technical field]

[0001] The present invention relates to a grinding device and a grinding material purging method. This application claims the benefit of priority based on Japanese Patent Application No. 2020-123547 filed on July 20, 2020, the contents of which are incorporated herein by reference. [Background technology]

[0002] The following Patent Document 1 discloses a method for purging residual coal from a coal pulverizer for a boiler. In this method, when restarting the pulverizer after an emergency shutdown, a blower that supplies drying air (a mixture of cold and hot air) to the pulverizer is operated to purge (purge) the residual coal in the pulverizer and in the pulverized coal discharge pipe to the boiler's coal burner, where the residual coal is burned. According to this method, the combustion of the residual coal in the coal burner can be detected by a flame detector, so that the pulverizer can be quickly restarted. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 63-57694 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned background art, the residual coal is burned by a coal burner, and the combustion is detected to recognize whether or not the purging of the residual coal is completed. Although this recognition allows for a quick restart, there is a problem that the residual coal cannot be purged sufficiently. That is, the drying air supplied from the blower to the pulverizer not only flows to the coal burner through the pulverized coal discharge pipe, but also leaks to routes other than the pulverized coal discharge pipe through various pipes connected to the pulverizer, so that the residual coal in the pulverized coal discharge pipe located at the most downstream of the drying air flow route cannot be purged sufficiently.

[0005] In view of the above-mentioned circumstances, an object of the present invention is to provide a crushing device and a crushed material purging method capable of purging residual crushed material more reliably. [Means for solving the problem]

[0006] One aspect of the present invention The system according to the present invention includes a main body that crushes a material to be crushed to produce a crushed material, a plurality of discharge pipes that are connected to the main body and supply the crushed material to a supply destination, It is provided separately from the main body, multiple A purge fluid supply section for supplying a predetermined purge fluid to the exhaust pipe of the and a control device. Equipped with Each of the plurality of exhaust pipes is provided with an outlet damper, the purge fluid supply unit includes a plurality of purge pipes connected to the plurality of exhaust pipes and a plurality of purge dampers provided in the plurality of purge pipes, and the control device is configured to execute the following operations after the main body is stopped: closing all of the outlet dampers of the plurality of exhaust pipes; and supplying purge fluid, the flow rate of which is adjusted by the plurality of purge dampers, from the purge fluid supply unit to the plurality of exhaust pipes without passing through the main body after all of the outlet dampers of the plurality of exhaust pipes are closed. .

[0007] The purging fluid may be primary cold air supplied to the body.

[0008] The purge fluid supply unit takes out the primary cold air from a cold air supply pipe that supplies the primary cold air to the main body, and supplies the taken out primary cold air to the multiple The exhaust pipe may be supplied with the above-mentioned.

[0009] A sealing air supply pipe that extracts sealing air to protect the rotating part of the main body may be connected to the cold air supply pipe, and the purge fluid supply unit may extract the primary cold air from the cold air supply pipe just before the sealing air supply pipe.

[0011] The main body may generate wood flour as the pulverized material by pulverizing woody biomass.

[0012] Another aspect of the present invention is A system comprising a main body for crushing a material to be crushed to produce a crushed material, a plurality of discharge pipes connected to the main body for supplying the crushed material to a supply destination, and a purge fluid supply unit provided separately from the main body for supplying a predetermined purge fluid to the plurality of discharge pipes, each of the plurality of discharge pipes being provided with an outlet damper, the purge fluid supply unit including a plurality of purge pipes connected to the plurality of discharge pipes and a plurality of purge dampers provided to the plurality of purge pipes, 1. A method for purging residual ground material from a discharge line, comprising: closing all of the outlet dampers of the plurality of exhaust pipes after the main body has stopped; and supplying a purge fluid from a purge fluid supply unit to the plurality of exhaust pipes in a state in which the flow rate is adjusted by the plurality of purge dampers without passing through the main body after all of the outlet dampers of the plurality of exhaust pipes have been closed; Includes. Effect of the Invention

[0013] According to the present invention, it is possible to provide a crushing device and a crushed material purging method that can more reliably purge residual crushed material. [Brief description of the drawings]

[0014] [Figure 1] 1 is a system configuration diagram showing the overall configuration of a grinding device A according to one embodiment of the present invention. [Diagram 2] 4 is a flowchart showing a purging operation of the crushing device A according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, a grinding device A and a grinding material purging method according to one embodiment of the present invention will be described with reference to the drawings. In the grinding device A according to this embodiment, woody biomass is the material to be ground, and wood flour is generated as the ground material by grinding the woody biomass. Such a grinding device A supplies the wood flour (ground material) to a supply destination such as a boiler.

[0016] As is well known, woody biomass is surplus wood such as thinned wood, and is mainly generated in the forestry business field. For example, such woody biomass is processed into pellets at the generation site and transported to the crushing site where the crushing device A is installed by a specified transportation means. In the following, woody biomass (crushed material) is abbreviated to biomass (crushed material).

[0017] As shown in FIG. 1, such a crushing device A includes a pellet bunker 1, a wood feeder 2, a pellet mill 3, a first discharge pipe 4, a first outlet damper 5, a second discharge pipe 6, a second outlet damper 7, a third discharge pipe 8, a third outlet damper 9, a cold air supply pipe 10, a cold air damper 11, a sealed air supply pipe 12, a sealed air damper 13, a shutoff damper 14, a check valve 15, a first purge pipe 16, a first purge damper 17, a second purge pipe 18, a second purge damper 19, a third purge pipe 20, a third purge damper 21, a hot air supply pipe 22, a primary air damper 23, and a crushing control device 24.

[0018] The pellet bunker 1 is a hopper with a specified capacity that receives biomass supplied from the outside. This pellet bunker 1 temporarily stores the biomass fed from above, and supplies the stored biomass from below to the wood feeder 2. Such a pellet bunker 1 functions as a buffer that temporarily stores a specified volume of biomass.

[0019] The wood feeder 2 is a biomass supplying device that weighs the biomass supplied from the pellet bunker 1 and supplies the biomass to the pellet mill 3. The wood feeder 2 measures the weight of the biomass supplied from the pellet bunker 1, for example, and supplies a constant weight of biomass to the pellet mill 3 per unit time.

[0020] That is, the wood feeder 2 manages the amount of biomass supplied to the pellet mill 3 as weight per unit time (kg / h) rather than as volume of biomass per unit time (m3 / h). The wood feeder 2 is a controlled device of the grinding control device 24, and its operation (supply amount) is controlled by the grinding control device 24.

[0021] The pellet mill 3 is a grinding machine that grinds the biomass supplied from the wood feeder 2. The pellet mill 3 generates wood flour as a ground product by pressurizing and grinding a predetermined amount of biomass sequentially supplied from the wood feeder 2 with an internal grinding mechanism.

[0022] Such a pellet mill 3 is, for example, a vertical mill, and includes a grinding mechanism including a rotary table that rotates in a horizontal plane and a grinding roller that presses the biomass between the rotary table and the rotary table. The pellet mill 3 is a controlled device of the grinding control device 24, and the overall operation of the pellet mill 3 is controlled by the grinding control device 24.

[0023] In this way, when the pellet mill 3 is a vertical mill, the biomass (material to be ground) is ground on the rotary table to become wood flour (ground material). This wood flour has a smaller particle size than the biomass, and is therefore lighter than the biomass. In addition, an upward air current is generated within the pellet mill 3, and this upward air current acts on the wood flour, blowing it upward from above the rotary table.

[0024] In the case of a vertical mill, a classifier is provided above the pellet mill 3. This classifier classifies the wood flour that enters from below on the upward flow, allowing only wood flour smaller than a predetermined standard particle size to pass outside the pellet mill 3, and wood flour larger than the standard particle size to fall and return to the rotating table. The wood flour returned to the rotating table is crushed again by a crushing mechanism into smaller-diameter powder, which then enters the classifier again via the upward flow.

[0025] In this way, in the pellet mill 3, wood flour smaller than the standard particle size is discharged from above to the outside. The three discharge pipes, i.e., the first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8, supply such wood flour smaller than the standard particle size, i.e., the product of the pellet mill 3, from the pellet mill 3 to a supply destination.

[0026] A discharge mechanism is provided on the upper part of the pellet mill 3 to divide wood powder smaller than the standard particle size supplied from the classifier into three approximately equal parts. This discharge mechanism distributes and supplies approximately equal amounts (discharge amounts) of wood powder to three discharge pipes (first discharge pipe 4, second discharge pipe 6, and third discharge pipe 8). The three discharge pipes (first discharge pipe 4, second discharge pipe 6, and third discharge pipe 8) are arranged, for example, on the upper surface of the pellet mill 3 at approximately equal intervals.

[0027] The above-mentioned pellet bunker 1, wood feeder 2, and pellet mill 3 constitute the main body of the crushing device A. In other words, the pellet bunker 1, wood feeder 2, and pellet mill 3 are mechanical parts that perform the main function of the crushing device A, namely, crushing biomass (material to be crushed), and also produce wood flour (material crushed) which is the output of the crushing device A.

[0028] The first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8 in this embodiment correspond to the discharge pipes of the present invention (also referred to as pulverized material discharge pipes in this disclosure). Of the first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8, one end of the first discharge pipe 4 is connected to the upper surface of the pellet mill 3, and the other end is connected to the fuel burner of the supply destination.

[0029] This first discharge pipe 4 is connected to the internal space of the pellet mill 3, and supplies a predetermined amount of wood powder supplied from the discharge mechanism to the fuel burner. Such a first discharge pipe 4 functions as a discharge pipe for discharging wood powder to the pellet mill 3, and functions as a supply pipe for supplying wood powder to the fuel burner.

[0030] The first outlet damper 5 is provided midway through the first discharge pipe 4 and is a flow rate adjusting device that adjusts the flow rate of wood powder passing through, i.e., the amount of wood powder supplied to the fuel burner. This first outlet damper 5 is, for example, a butterfly valve, and adjusts the amount of wood powder supplied by varying the passage area (opening) of the wood powder. Note that this first outlet damper 5 is a controlled device of the grinding control device 24, and the passage area (opening) is set by the grinding control device 24.

[0031] One end of the second discharge pipe 6 is connected to the top surface of the pellet mill 3, and the other end is connected to the fuel burner to which the wood powder is supplied. This second discharge pipe 6 is connected to the internal space of the pellet mill 3, and supplies a predetermined amount of wood powder supplied from the discharge mechanism to the fuel burner. This second discharge pipe 6 functions as a discharge pipe for discharging wood powder from the pellet mill 3, and also functions as a supply pipe for supplying wood powder to the fuel burner.

[0032] The second outlet damper 7 is provided midway through the second discharge pipe 6 and is a flow rate adjusting device that adjusts the flow rate of wood powder passing through, i.e., the amount of wood powder supplied to the fuel burner. This second outlet damper 7 is, for example, a butterfly valve, and adjusts the amount of wood powder supplied by varying the passage area (opening) of the wood powder. Note that this second outlet damper 7 is a controlled device of the grinding control device 24, and the passage area (opening) is set by the grinding control device 24.

[0033] One end of the third discharge pipe 8 is connected to the top surface of the pellet mill 3, and the other end is connected to the fuel burner to which the wood powder is supplied. This third discharge pipe 8 is connected to the internal space of the pellet mill 3, and supplies a predetermined amount of wood powder supplied from the discharge mechanism to the fuel burner. This third discharge pipe 8 functions as a discharge pipe for discharging wood powder to the pellet mill 3, and functions as a supply pipe for supplying wood powder to the fuel burner.

[0034] The third outlet damper 9 is provided midway through the third discharge pipe 8 and is a flow rate adjusting device that adjusts the flow rate of wood powder passing through, i.e., the amount of wood powder supplied to the fuel burner. This third outlet damper 9 is, for example, a butterfly valve, and adjusts the amount of wood powder supplied by varying the passage area (opening) of the wood powder. Note that this third outlet damper 9 is a controlled device of the grinding control device 24, and the passage area (opening) is set by the grinding control device 24.

[0035] A plurality of fuel burners are provided at the supply destination of a boiler or the like. The plurality of combustion burners are divided into several groups. Each group is composed of, for example, a plurality of combustion burners. For example, three such groups are provided, and the above-mentioned three exhaust pipes (the first exhaust pipe 4, the second exhaust pipe 6, and the third exhaust pipe 8) are provided corresponding to each group.

[0036] That is, as shown in FIG. 1, the first exhaust pipe 4 is connected to a plurality of fuel burners constituting the first group burner. The second exhaust pipe 6 supplies wood powder as fuel to the plurality of fuel burners constituting the second group of burners. The third exhaust pipe 8 supplies wood powder as fuel to the plurality of fuel burners constituting the third group of burners.

[0037] That is, the first exhaust pipe 4 is a first supply pipe that supplies wood powder as fuel to the multiple combustion burners that make up the first group. The second exhaust pipe 6 is a second supply pipe that supplies wood powder as fuel to the multiple combustion burners that make up the second group. The third exhaust pipe 8 is a third supply pipe that supplies wood powder as fuel to the multiple combustion burners that make up the third group.

[0038] One end of the cold air supply pipe 10 is connected to an external cold air supply source, and the other end is connected to a midpoint of the hot air supply pipe 22. More specifically, the other end of the cold air supply pipe 10 is connected to the upstream side of the primary air damper 23. This cold air supply pipe 10 supplies primary cold air received from the cold air supply source to the hot air supply pipe 22. The primary cold air is air in the same temperature range as the outside air, and is mixed with the primary hot air flowing through the hot air supply pipe 22. Such primary cold air corresponds to the purge fluid of the present invention.

[0039] The cold air damper 11 is provided in the middle of the cold air supply pipe 10, and is a flow rate adjusting device that adjusts the flow rate of primary cold air passing through the cold air supply pipe 10. This cold air damper 11 is, for example, a butterfly valve, and adjusts the supply amount of primary cold air flowing into the hot air supply pipe 22 by varying the passing area (opening) of the primary cold air. Such a cold air damper 11 is a controlled device of the pulverization control device 24, and the passing area (opening) is set by the pulverization control device 24.

[0040] One end of the sealed air supply pipe 12 is connected to an intermediate portion of the cold air supply pipe 10, and the other end is connected to the pellet mill 3. More specifically, one end of the sealed air supply pipe 12 is connected to the upstream side of the cold air damper 11 in the flow direction of the primary cold air. This sealed air supply pipe 12 supplies the primary cold air as sealed air for protecting various rotating parts of the pellet mill 3.

[0041] The sealed air damper 13 is provided in the middle of the sealed air supply pipe 12, and is a flow rate adjusting device that adjusts the flow rate of the primary cold air passing through the sealed air supply pipe 12. This sealed air damper 13 is, for example, a butterfly valve, and adjusts the supply amount of the primary cold air flowing into the pellet mill 3 by varying the passing area (opening) of the primary cold air. Such a sealed air damper 13 is a controlled device of the pulverization control device 24, and the passing area (opening) is set by the pulverization control device 24.

[0042] The shutoff damper 14 is provided between the seal air damper 13 and the check valve 15 in the seal air supply pipe 12. This shutoff damper 14 is an on-off valve, and shuts off / allows the flow of primary cold air in the seal air supply pipe 12. That is, the opening degree of this shutoff damper 14 is set to two values, fully closed or fully open, and when fully closed, it shuts off the inflow of primary cold air into the pellet mill 3, and when fully open, it allows the inflow of primary cold air into the pellet mill 3. Such a shutoff damper 14 is a controlled device of the grinding control device 24, and the open / closed state is set by the grinding control device 24.

[0043] The check valve 15 prevents the backflow of air. That is, the check valve 15 prevents the air in the pellet mill 3 from flowing from the other end (pellet mill 3) of the sealing air supply pipe 12 toward one end of the sealing air supply pipe 12. This check valve 15 is intended to prevent the air in the pellet mill 3 from flowing into the sealing air supply pipe 12 due to an abnormally high internal pressure of the pellet mill 3.

[0044] One end of the first purge pipe 16 is connected to the cold air supply pipe 10, and the other end is connected to the first exhaust pipe 4. More precisely, one end of the first purge pipe 16 is connected to the upstream side of the cold air damper 11 in the cold air supply pipe 10. In addition, the other end of the first purge pipe 16 is connected to the downstream side of the first outlet damper 5 in the first exhaust pipe 4.

[0045] Such a first purge pipe 16 is a bypass pipe for circulating the primary cold air to the first discharge pipe 4, and is provided exclusively for the first discharge pipe 4. That is, when the main body of the above-mentioned crushing device A, that is, the pellet bunker 1, the wood feeder 2, and the pellet mill 3, stops operating, the first purge pipe 16 supplies primary cold air to the first discharge pipe 4 instead of the pellet mill 3. Such a first purge pipe 16 purges (removes) the residual wood powder (residual crushed material) in the first discharge pipe 4 with the primary cold air.

[0046] The first purge damper 17 is provided in the middle of the first purge pipe 16 and is a flow rate adjusting device that adjusts the flow rate of the primary cold air passing through the first purge pipe 16. The first purge damper 17 is, for example, a butterfly valve, and adjusts the supply amount of the primary cold air flowing into the first discharge pipe 4 by varying the passing area (opening) of the primary cold air. The first purge damper 17 is a controlled device of the pulverization control device 24, and the passing area (opening) is set by the pulverization control device 24.

[0047] One end of the second purge pipe 18 is connected to the cold air supply pipe 10, and the other end is connected to the second exhaust pipe 6. More precisely, one end of the second purge pipe 18 is connected to the upstream side of the cold air damper 11 in the cold air supply pipe 10. In addition, the other end of the second purge pipe 18 is connected to the downstream side of the second outlet damper 7 in the second exhaust pipe 6.

[0048] Such a second purge pipe 18 is a bypass pipe for circulating the primary cold air to the second discharge pipe 6, and is provided exclusively for the second discharge pipe 6. That is, when the main body of the above-mentioned crushing device A, that is, the pellet bunker 1, the wood feeder 2, and the pellet mill 3, stops operating, the second purge pipe 18 supplies primary cold air to the second discharge pipe 6 instead of the pellet mill 3. Such a second purge pipe 18 purges (removes) the residual wood powder (residual crushed material) in the second discharge pipe 6 with the primary cold air.

[0049] The second purge damper 19 is provided in the middle of the second purge pipe 18, and is a flow rate adjusting device that adjusts the flow rate of the primary cold air passing through the second purge pipe 18. The second purge damper 19 is, for example, a butterfly valve, and adjusts the supply amount of the primary cold air flowing into the second discharge pipe 6 by varying the passing area (opening) of the primary cold air. The second purge damper 19 is a controlled device of the pulverization control device 24, and the passing area (opening) is set by the pulverization control device 24.

[0050] One end of the third purge pipe 20 is connected to the cold air supply pipe 10, and the other end is connected to the third exhaust pipe 8. More precisely, one end of the third purge pipe 20 is connected to the upstream side of the cold air damper 11 in the cold air supply pipe 10. In addition, the other end of the third purge pipe 20 is connected to the downstream side of the third outlet damper 9 in the third exhaust pipe 8.

[0051] Such a third purge pipe 20 is a bypass pipe for circulating the primary cold air to the third discharge pipe 8, and is provided exclusively for the third discharge pipe 8. That is, when the main body of the above-mentioned crushing device A, that is, the pellet bunker 1, the wood feeder 2, and the pellet mill 3, stops operating, the third purge pipe 20 supplies primary cold air to the third discharge pipe 8 instead of the pellet mill 3. Such a third purge pipe 20 purges (removes) the residual wood powder (residual crushed material) in the third discharge pipe 8 with the primary cold air.

[0052] The third purge damper 21 is provided in the middle of the third purge pipe 20 and is a flow rate adjusting device that adjusts the flow rate of the primary cold air passing through the third purge pipe 20. The third purge damper 21 is, for example, a butterfly valve, and adjusts the supply amount of the primary cold air flowing into the third discharge pipe 8 by varying the passing area (opening) of the primary cold air. The third purge damper 21 is a controlled device of the pulverization control device 24, and the passing area (opening) is set by the pulverization control device 24.

[0053] The above-mentioned first purge pipe 16, first purge damper 17, second purge pipe 18, second purge damper 19, third purge pipe 20, and third purge damper 21 constitute the purge fluid supply unit of the present invention. That is, these first purge pipe 16, first purge damper 17, second purge pipe 18, second purge damper 19, third purge pipe 20, and third purge damper 21 are provided separately from the main body, and supply primary cold air as a predetermined purge fluid to the exhaust pipes (first exhaust pipe 4, second exhaust pipe 6, and third exhaust pipe 8) when the main body stops.

[0054] One end of the hot air supply pipe 22 is connected to an external hot air supply source, and the other end is connected to the pellet mill 3. This hot air supply pipe 22 supplies primary hot air received from the hot air supply source to the pellet mill 3. The primary hot air is generated by heating outside air, and therefore has a higher temperature than the primary cold air. This primary hot air is supplied to the pellet mill 3 in the same manner as the primary cold air in order to generate the above-mentioned upward flow.

[0055] The primary air damper 23 is provided in the middle of the hot air supply pipe 22, that is, downstream of the connection position of the other end of the cold air supply pipe 10 to the hot air supply pipe 22. The primary air damper 23 is a flow rate adjusting device that adjusts the flow rate of mixed air (primary air) of primary cold air and primary hot air generated at the connection position of the cold air supply pipe 10 and the hot air supply pipe 22.

[0056] This primary air damper 23 is, for example, a butterfly valve, and adjusts the supply amount of primary air flowing into the pellet mill 3 by varying the passing area (opening) of the primary air. Such a primary air damper 23 is a controlled device of the pulverization control device 24, and the passing area (opening) is set by the pulverization control device 24.

[0057] The grinding control device 24 controls the above-mentioned controlled devices to comprehensively operate the grinding device A. Although omitted in Fig. 1, the grinding control device 24 is electrically connected to the controlled devices, namely, the wood feeder 2, the pellet mill 3, the first outlet damper 5, the second outlet damper 7, the third outlet damper 9, the cold air damper 11, the seal air damper 13, the shutoff damper 14, the first purge damper 17, the second purge damper 19, the third purge damper 21, and the primary air damper 23, via control wires.

[0058] The grinding control device 24 detects the operating state of the controlled devices through the control wires and outputs operation signals to the controlled devices. That is, the grinding control device 24 controls the operation of the wood feeder 2 and the pellet mill 3 based on the operation signals, and appropriately sets the opening degrees of the first outlet damper 5, the second outlet damper 7, the third outlet damper 9, the cold air damper 11, the seal air damper 13, the shutoff damper 14, the first purge damper 17, the second purge damper 19, the third purge damper 21, and the primary air damper 23.

[0059] Next, the operation of the crushing device A according to this embodiment will be described in detail with reference to the flowchart shown in FIG.

[0060] First, we will explain the normal operation of the grinding device A. The grinding control device 24 outputs operation signals to the controlled devices (wood feeder 2, pellet mill 3, first outlet damper 5, second outlet damper 7, third outlet damper 9, cold air damper 11, sealed air damper 13, shutoff damper 14, first purge damper 17, second purge damper 19, third purge damper 21, and primary air damper 23) to grind the biomass (material to be ground) in sequence, and sequentially supply the resulting wood flour (ground material) to the supply destination.

[0061] When the pulverization control device 24 detects any abnormality in the pulverization device A, it brings the pulverization device A to an emergency stop (step S1). For example, when it detects an abnormality in the wood feeder 2, the pellet mill 3, the first outlet damper 5, the second outlet damper 7, the third outlet damper 9, the cold air damper 11, the sealed air damper 13, the shutoff damper 14, the first purge damper 17, the second purge damper 19, the third purge damper 21, and the primary air damper 23, which are the control targets, the pulverization control device 24 brings the pulverization device A to an emergency stop.

[0062] When the crushing device A undergoes an emergency stop, the manager who manages the operation of the crushing device A identifies the cause of the emergency stop and takes measures. As a result, the crushing device A returns to a state in which normal operation is possible. Then, when the manager confirms that the abnormality of the crushing device A has been resolved, he inputs a restart command to the crushing control device 24. This restart command is input to the crushing control device 24 using an operation panel that is annexed to the crushing control device 24.

[0063] When the pulverization control device 24 judges (recognizes) the input of such a restart command (step S2), it first sets the first outlet damper 5, the second outlet damper 7, and the third outlet damper 9 to a fully closed state (step S3). That is, the pulverization control device 24 completely cuts off communication between the first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8 and the pellet mill 3 by setting the first to third outlet dampers 5, 7, and 9 to a fully closed state.

[0064] Next, the pulverization control device 24 sets the cold air damper 11 provided in the cold air supply pipe 10 to a fully closed state (step S4). That is, the pulverization control device 24 blocks the communication state of the cold air supply pipe 10 at the position of the cold air damper 11. As a result, it is possible to completely prevent the primary cold air of the cold air supply pipe 10 from flowing into the hot air supply pipe 22 and then into the pellet mill 3 via the hot air supply pipe 22.

[0065] Furthermore, the pulverization control device 24 sets the shutoff damper 14 provided in the middle of the sealed air supply pipe 12 to a fully closed state (step S5). That is, the pulverization control device 24 completely shuts off the communication state between the cold air supply pipe 10 and the pellet mill 3 through the sealed air supply pipe 12. As a result, the primary cold air of the cold air supply pipe 10 is completely prevented from flowing into the pellet mill 3 via the sealed air supply pipe 12.

[0066] When the first outlet damper 5, the second outlet damper 7, the third outlet damper 9, the cold air damper 11, and the shutoff damper 14 are set to the fully closed state, the pulverization control device 24 sets the first purge damper 17, the second purge damper 19, and the third purge damper 21 to the fully open state (step S6). By setting the first purge damper 17, the second purge damper 19, and the third purge damper 21 to the fully open state, the primary cold air that flows from the air supply source into the cold air supply pipe 10 flows entirely into the first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8.

[0067] That is, primary cold air is sequentially supplied to the first exhaust pipe 4 via the first purge pipe 16, primary cold air is sequentially supplied to the second exhaust pipe 6 via the second purge pipe 18, and primary cold air is sequentially supplied to the third exhaust pipe 8 via the third purge pipe 20.

[0068] Then, the pulverization control device 24 measures the elapsed time from the process of step S5, that is, the elapsed time from the start of the supply of primary cold air to the first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8, and judges whether or not the elapsed time exceeds the time threshold value T (step S7). If the judgment in step S7 is "Yes", that is, if the elapsed time exceeds the time threshold value T, the pulverization control device 24 notifies the administrator that the purging of the first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8 has been completed (step S8).

[0069] According to this embodiment, primary cold air taken out from the cold air supply pipe 10 is supplied to the first discharge pipe 4, the second discharge pipe 6 and the third discharge pipe 8 via the first purge pipe 16, the second purge pipe 18 and the third purge pipe 20, so that it is possible to more reliably purge the residual wood powder (residual crushed material) remaining in the first discharge pipe 4, the second discharge pipe 6 and the third discharge pipe 8 in the event of an emergency stop of the grinding device A.

[0070] In other words, when primary cold air is supplied to the first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8 via the pellet mill 3, it is not possible to supply a sufficient amount and pressure of primary cold air to the first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8 due to leakage of the primary cold air in the pellet mill 3, etc.

[0071] However, in this embodiment, the primary cold air is supplied to the first discharge pipe 4, the second discharge pipe 6 and the third discharge pipe 8 via the first purge pipe 16, the second purge pipe 18 and the third purge pipe 20 without passing through the pellet mill 3, so that a sufficient amount and pressure of primary cold air can be supplied for purging the residual wood powder (residual crushed material).

[0072] Therefore, according to this embodiment, the purging of the residual wood powder (residual crushed material) in the first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8 can be performed more reliably than in the past. Furthermore, according to this embodiment, the purging of the residual wood powder (residual crushed material) in the first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8 can be performed in a shorter time than in the past, so that the crushing device A can be restarted after an emergency stop in a shorter time than in the past.

[0073] In this embodiment, primary cold air is used as the purging fluid supplied to the first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8. Since this primary cold air has a lower temperature than the primary hot air, it is possible to more reliably prevent the ignition of residual wood powder (residual crushed material), which is a concern when the purging fluid is supplied to the first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8.

[0074] In this embodiment, one end of each of the first purge pipe 16, the second purge pipe 18, and the third purge pipe 20 is connected to the upstream side of the seal air supply pipe 12, which circulates primary cold air (seal air) for protecting the rotating part of the pellet mill 3. That is, in this embodiment, primary cold air is taken out from the cold air supply pipe 10 just before the seal air supply pipe 12 as a purge fluid and supplied to the first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8.

[0075] According to this embodiment, it is possible to supply primary cold air (purge fluid) to the first discharge pipe 4, the second discharge pipe 6 and the third discharge pipe 8 regardless of the supply of primary cold air (sealing air) to the rotating part of the pellet mill 3.

[0076] In this embodiment, a first purge damper 17, a second purge damper 19 and a third purge damper 21 are provided in the first purge pipe 16, the second purge pipe 18 and the third purge pipe 20, respectively. That is, in this embodiment, primary cold air (purge fluid) is supplied to a plurality of exhaust pipes, that is, the first exhaust pipe 4, the second exhaust pipe 6 and the third exhaust pipe 8, respectively, with the flow rate being adjusted.

[0077] According to this embodiment, it is possible to individually adjust the flow rate of the primary cold air (purge fluid) supplied to the first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8. According to this embodiment, it is possible to appropriately set the flow rate of the primary cold air (purge fluid) depending on the amount of residual wood powder (residual ground material) in the first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8, for example.

[0078] The present invention is not limited to the above-described embodiment, and the following modifications are possible. (1) In the above embodiment, a grinding device A (biomass mill) is described that grinds woody biomass as a material to be ground to produce wood flour as a ground material, but the present invention can be applied to grinding various materials. At least the present invention can be applied to a grinding device that grinds coal as a material to be ground to produce pulverized coal as a ground material.

[0079] (2) In the above embodiment, the primary cold air is used as the purge fluid, but the present invention is not limited thereto. For example, the primary hot air may be used as the purge fluid instead of the primary cold air. The selection conditions for the purge fluid are that it has a flow rate and pressure that can sufficiently purge the residual wood powder (residual crushed material) in the first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8, and preferably has a temperature around room temperature.

[0080] (3) In the above embodiment, the first outlet damper 5, the second outlet damper 7, the third outlet damper 9, the cold air damper 11, and the shutoff damper 14 are all fully closed, and the first purge damper 17, the second purge damper 19, and the third purge damper 21 are all fully open, thereby supplying primary cold air (purge fluid) to the first exhaust pipe 4, the second exhaust pipe 6, and the third exhaust pipe 8, but the present invention is not limited to this.

[0081] For example, since the required flow rate of the primary cold air (sealed air) is relatively small, the first outlet damper 5, the second outlet damper 7, the third outlet damper 9 and the cold air damper 11 are set to a fully closed state, but the shutoff damper 14 is set to a fully open state and the first purge damper 17, the second purge damper 19 and the third purge damper 21 are set to a fully open state.

[0082] (4) In the above embodiment, the first purge damper 17, the second purge damper 19, and the third purge damper 21 are provided in the first purge pipe 16, the second purge pipe 18, and the third purge pipe 20, respectively, but the present invention is not limited to this. For example, instead of the first purge damper 17, the second purge damper 19, and the third purge damper 21, a single purge damper having an intake port connected to the cold air supply pipe 10 and an exhaust port connected to one end of each of the first purge pipe 16, the second purge pipe 18, and the third purge pipe 20 may be provided.

[0083] (5) In the above embodiment, the present invention is applied to the crushing device A having three discharge pipes (the first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8), but the present invention is not limited to this. In other words, the present invention is also applicable to a crushing device having one or more discharge pipes other than three.

[0084] (6) In the above embodiment, as shown in Fig. 2, the first outlet damper 5, the second outlet damper 7, and the third outlet damper 9 are set to a fully closed state (step S3), then the cold air damper 11 is set to a fully closed state (step S4), and finally the shutoff damper 14 is set to a fully closed state (step S5). However, the order in which the dampers are set to a fully closed state is not limited to this, and other orders may be used.

[0085] (7) In the above embodiment, the primary cold air is taken out as a purge fluid from the cold air supply pipe 10 just before the seal air supply pipe 12 and supplied to the first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8, but the present invention is not limited to this. If necessary, the primary cold air (purge fluid) may be taken out from an intermediate portion of the seal air supply pipe 12 and supplied to the first discharge pipe 4, the second discharge pipe 6, and the third discharge pipe 8. For example, the primary cold air (purge fluid) may be taken out from between the seal air damper 13 and the shutoff damper 14 in the seal air supply pipe 12. [Explanation of symbols]

[0086] A Crushing device 1 Pellet Bunker (main body) 2 Wood feeder (main unit) 3 Pellet mill (main body) 4 1st discharge pipe (discharge pipe) 5. First outlet damper 6 2nd discharge pipe (discharge pipe) 7 Second outlet damper 8 Third discharge pipe (discharge pipe) 9. 3rd outlet damper 10 Cold air supply pipe 11 Cold air damper 12 Sealed air supply pipe 13 Seal air damper 14. Isolation damper 15 Check valve 16 First purge pipe 17 First purge damper 18 Second purge pipe 19 Second purge damper 20. Third purge pipe 21 3rd purge damper 22 Hot air supply pipe 23 Primary air damper 24 Grinding control device

Claims

1. A main body for crushing a material to be crushed to produce a crushed material; A plurality of discharge pipes connected to the main body and supplying the pulverized material to a supply destination; a purge fluid supply unit provided separately from the main body and configured to supply a predetermined purge fluid to the plurality of exhaust pipes; A control device; Equipped with Each of the plurality of exhaust pipes is provided with an outlet damper, The purge fluid supply unit includes: A plurality of purge pipes connected to the plurality of exhaust pipes; a plurality of purge dampers provided in the plurality of purge pipes; Including, The control device includes: closing all of the outlet dampers of the plurality of exhaust pipes after the main body has stopped; After all of the outlet dampers of the plurality of exhaust pipes are closed, the purge fluid is supplied from the purge fluid supply unit to the plurality of exhaust pipes without passing through the main body, with the flow rate being adjusted by the plurality of purge dampers; configured to execute system.

2. 2. The system of claim 1, wherein said purging fluid is primary cold air supplied to said body.

3. The system of claim 2 , wherein the purge fluid supply unit extracts the primary cold air from a cold air supply pipe that supplies the primary cold air to the main body, and supplies the extracted primary cold air to the plurality of exhaust pipes.

4. A seal air supply pipe for extracting seal air for protecting a rotating part of the main body is connected to the cold air supply pipe, The system of claim 3 , wherein the purge fluid supply derives the primary cold air from the cold air supply line prior to the seal air supply line.

5. The system according to any one of claims 1 to 4, wherein the main body generates wood powder as the pulverized material by pulverizing wood biomass.

6. A method for purging residual crushed material from a plurality of discharge pipes in a system including a main body for crushing a material to be crushed to produce a crushed material, a plurality of discharge pipes connected to the main body and supplying the crushed material to a destination, and a purge fluid supply unit provided separately from the main body and supplying a predetermined purging fluid to the plurality of discharge pipes, each of the plurality of discharge pipes being provided with an outlet damper, the purge fluid supply unit including a plurality of purge pipes connected to the plurality of discharge pipes and a plurality of purge dampers provided in the plurality of purge pipes, comprising: closing all of the outlet dampers of the plurality of exhaust pipes after the main body has stopped; After all of the outlet dampers of the plurality of exhaust pipes are closed, the purge fluid is supplied from the purge fluid supply unit to the plurality of exhaust pipes without passing through the main body, with the flow rate being adjusted by the plurality of purge dampers; A method comprising:

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