Grinding device and cement manufacturing method

Abstract

To provide a crusher which is useful for suppressing an influence of cement powder on a cooling device, and a cement manufacturing method.SOLUTION: A crusher includes: a mill apparatus in which a plurality of pulverizing balls are housed, and which has a supply chute 14 for supplying a crushing object containing cement clinker into a drum, and which crushes the crushing object by rotating the drum; and a cooling device 40 for supplying a coolant into the drum. The cooling device includes: a sheath pipe 70 whose tip 72 is positioned inside the mill apparatus, and whose base end 74 is provided in the supply chute so as to be positioned outside of the mill apparatus; a supply pipe 44 which is arranged inside the sheath pipe, and leads the coolant to a discharge part 42 provided at the tip; and a drive device 46 which causes the supply pipe to move along an extended direction of the sheath pipe, between a discharge position P1 where the discharge part is disposed inside the mill apparatus in a state of protruding from the tip of the sheath pipe, and a retreat position P2 where the discharge part is disposed so as to be separated from the inside of the mill apparatus beyond the tip.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a grinding device and a method for producing cement. [Background technology]

[0002] Patent Document 1 discloses a method for treating industrial wastewater, in which industrial wastewater is dispersed and added to cement clinker in a process for finishing and crushing the clinker, etc. Patent Document 2 discloses a method for treating industrial wastewater, in which washing wastewater discharged from a semiconductor factory is fed as a crushing aid into a crusher in a cement manufacturing facility for disposal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-238244 A [Patent Document 2] JP 2003-2706 A Summary of the Invention [Problem to be solved by the invention]

[0004] A grinding machine that performs a grinding process for producing cement is equipped with a cooling device that supplies a cooling liquid such as water to the inside of the grinding machine to prevent an increase in the internal temperature. The present disclosure provides a grinding device and a method for producing cement that are useful for suppressing the impact of cement powder on the cooling device. [Means for solving the problem]

[0005] A grinding device according to one aspect of the present disclosure includes a mill device having a drum that accommodates a plurality of grinding balls and is rotatable about a predetermined axis, a supply chute that supplies materials to be ground, including cement clinker, to the inside of the drum and grinds the materials to be ground by rotating the drum, and a cooling device that supplies a cooling liquid to the inside of the drum. The cooling device includes a sheath tube that includes a tip end and a base end and is provided on the supply chute so that the tip end is located inside the mill device and the base end is located outside the mill device, a supply pipe that is provided inside the sheath tube and guides the cooling liquid to a discharge portion provided at the tip end, and a drive device that moves the supply pipe along the extension direction of the sheath tube between a discharge position where the discharge portion is located inside the mill device while protruding beyond the tip end of the sheath tube and a retracted position where the discharge portion is located away from the inside of the mill device relative to the tip end.

[0006] In the mill device for grinding cement, cement powder is suspended. Therefore, after the cooling liquid from the discharge part is stopped, the cooling liquid adhering to the discharge part reacts with the cement powder, and a cement lump may be generated around the discharge part. In response to this, in the above-mentioned grinding device, the supply pipe for leading the cooling liquid to the discharge part is movable between the discharge position and a retreat position where the discharge part is farther from the inside of the mill device than the tip of the sheath tube. Therefore, when the cooling liquid from the discharge part is stopped, the discharge part can be retreated from the inside of the mill device, so that a cement lump is less likely to be generated around the discharge part. Therefore, it is useful for suppressing the influence of the cement powder on the cooling device.

[0007] The tip and base ends may be open so that the inside and outside of the mill apparatus are connected via the space in the sheath tube. In this configuration, when gas inside the mill apparatus is sucked, air is taken into the inside of the mill apparatus from the outside via the space between the sheath tube and the supply piping. This air flow can suppress the generation of stagnation in the space between the sheath tube and the supply piping. Therefore, it is useful for improving the maintainability of the cooling device.

[0008] The sleeve pipe may be inclined obliquely downward toward the inside of the mill apparatus. In this case, it is possible to suppress the release of cement powder or lumps from the inside of the mill apparatus without providing a backflow prevention device inside the sleeve pipe. Therefore, it is useful for simplifying the configuration of the cooling device.

[0009] The tip of the sleeve pipe may be formed with a sharp point that protrudes toward the inside of the mill device. In this case, even if a large lump of cement is formed around the discharge part during the supply of the cooling liquid, the lump can be removed by the sharp point of the sleeve pipe when the supply pipe is moved so that the discharge part is accommodated inside the sleeve pipe. This is therefore useful for improving the maintainability of the cooling device.

[0010] The tip of the sheath pipe may have a tip surface extending crosswise with respect to the extension direction of the sheath pipe so as to form the pointed portion. The angle between the tip surface and the extension direction of the sheath pipe may be 30° to 60°. In this case, when the supply piping is moved so that the discharge portion is housed in the sheath pipe, a force can be applied from the sheath pipe to a point of a lump of cement that may be formed on the discharge portion, making it easy to remove the lump. This is therefore useful for improving the maintainability of the cooling device.

[0011] The sleeve pipe may be provided in the supply chute such that the pointed portion is located between the area in the supply chute through which the material to be crushed passes and the supply pipe. In this case, the material to be crushed passing through the supply chute is less likely to enter the inside of the sleeve pipe, and the generation of stagnation in the sleeve pipe is suppressed. Therefore, it is useful for improving the maintainability of the cooling device.

[0012] The above-mentioned grinding device may further include a switching device for switching between a state in which the discharge unit discharges the cooling liquid and a state in which the discharge unit does not discharge the cooling liquid, a temperature measuring device for acquiring temperature information indicating the temperature inside the drum, and a control device for controlling the driving device, the switching device, and the temperature measuring device. When the temperature indicated by the temperature information exceeds a predetermined set temperature, the control device may execute the following: moving the supply pipe to the discharge position by the driving device, and controlling the switching device to discharge the cooling liquid from the discharge unit with the supply pipe disposed at the discharge position. When the temperature indicated by the temperature information falls below the predetermined set temperature, the control device may execute the following: controlling the switching device to stop the discharge of the cooling liquid from the discharge unit, and moving the supply pipe to the retracted position by the driving device. In this case, the generation of cement lumps at the discharge unit can be suppressed while efficiently supplying the cooling liquid into the mill device. Therefore, it is useful for efficient cooling of the inside of the mill device and improving the maintainability of the cooling device.

[0013] The grinding device may further include an injection device that injects compressed air into the supply pipe so that the cooling liquid is discharged from the discharge part. In this case, the cooling liquid in the supply pipe can be discharged from the discharge part, so that the generation of cement lumps at the discharge part due to the cooling liquid remaining in the supply pipe can be suppressed. Therefore, it is useful for suppressing the influence on the cooling device caused by the reaction between the cooling liquid and the cement powder when the discharge is stopped.

[0014] The above-mentioned grinding device may further include a control device for controlling the drive device and the injection device. The control device may execute the injection device to inject compressed air into the supply pipe when the supply pipe is disposed at the discharge position. The control device may execute the drive device to move the supply pipe to the retracted position when the discharge unit is not discharging the cooling liquid after the compressed air is injected into the supply pipe. In this case, the cooling liquid in the supply pipe is discharged when the discharge unit is disposed inside the mill device. Therefore, the discharged cooling liquid is not dispersed in areas other than the inside of the mill device. Therefore, it is useful for reducing the influence of the cooling liquid discharged in association with the injection of compressed air into the supply pipe while suppressing the generation of cement lumps at the discharge unit.

[0015] A method for producing cement according to one aspect of the present disclosure includes a step of producing cement clinker by calcining a cement raw material, and a step of crushing an object to be crushed, which includes cement clinker and gypsum, using any one of the crushing devices described above. In this method for producing cement, the object to be crushed is crushed using any one of the crushing devices described above. Therefore, similar to the crushing device described above, the method is useful for suppressing the effect of cement powder on a cooling device. Effect of the Invention

[0016] According to the present disclosure, a grinding device and a method for producing cement that are useful for suppressing the impact of cement powder on a cooling device are provided. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic diagram showing an example of a crushing device. [Diagram 2] FIG. 2 is a schematic diagram showing a part of the cooling device in a state in which a cooling liquid is being supplied. [Diagram 3] FIG. 3 is a schematic diagram showing a part of the cooling device in a retracted state. [Figure 4] Fig. 4(a) is a side view showing an example of the tip of a sheath tube, and Fig. 4(b) is a top view showing a cross section of the tip of the sheath tube. [Diagram 5] FIG. 5 is a top view that illustrates a schematic example of an arrangement of sleeve pipes in the supply chute. [Figure 6] FIG. 6 is a block diagram illustrating an example of a hardware configuration of the control device. [Figure 7] FIG. 7 is a flowchart showing an example of a series of processes executed by the control device. [Figure 8] FIG. 8 is a schematic diagram showing an example of a cooling device. [Figure 9] FIG. 9 is a flowchart showing an example of a series of processes executed by the control device. [Figure 10] FIG. 10 is a flowchart showing an example of a series of processes executed by the control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] An embodiment will be described below with reference to the drawings. In the description, the same elements or elements having the same functions are given the same reference numerals, and duplicated descriptions will be omitted. Some drawings show an orthogonal coordinate system defined by an X-axis, a Y-axis, and a Z-axis. In the following embodiment, the Z-axis corresponds to the vertical direction, and the X-axis and the Y-axis correspond to the horizontal direction.

[0019] The pulverizing device 1 shown in Fig. 1 is installed in a cement manufacturing facility and is a device that performs a pulverizing process included in a finishing process. Specifically, the pulverizing device 1 pulverizes a pulverizing target that contains cement clinker (hereinafter simply referred to as "clinker") and gypsum generated in a previous burning process, while mixing the gypsum with the clinker. The pulverizing device 1 is a device that performs finish pulverization (finish pulverizer), and powder (fine powder) generated by pulverization by the pulverizing device 1 is discharged from the pulverizing device 1 as cement.

[0020] The crushing device 1 is supplied with clinker from a clinker silo 92, and with gypsum from a gypsum storage area 94. The clinker silo 92 may store clinker that has been crushed by a preliminary crusher such as a vertical mill. The crushing device 1 includes a mill device 10, a dust collection fan 22, a dust collection device 24, a temperature measuring device 30, a cooling device 40, and a control device 100.

[0021] The mill apparatus 10 is an apparatus for pulverizing an object to be pulverized by using pulverizing media. The pulverizing media are balls (hereinafter referred to as "pulverizing balls 18") for pulverizing the object to be pulverized, and are, for example, steel balls. The mill apparatus 10 is also called a tube mill (finishing mill). The mill apparatus 10 has a drum 12, a supply chute 14, and a connection portion 16.

[0022] The drum 12 is a container that contains a plurality (a large number) of grinding balls 18 and is rotatable around a predetermined axis. The drum 12 extends, for example, along one horizontal direction (for example, the X-axis direction in the drawing) and is formed in a cylindrical shape. The above-mentioned predetermined axis may be an axis that extends along the extension direction of the drum 12 and passes through the center of the drum 12 in a cross section perpendicular to the extension direction. A driving device that imparts a driving force is connected to the drum 12. The mill device 10 rotates the drum 12 around the above-mentioned axis with the object to be ground being supplied into the drum 12. As a result, the grinding balls 18 and the object to be ground collide with each other in the drum 12, and the object to be ground is ground.

[0023] The supply chute 14 supplies the materials to be crushed transported from the silo 92 and the storage area 94 into the inside of the drum 12. An inlet for the materials to be crushed is provided at one end of the supply chute 14, and the other end of the supply chute 14 is connected to the end of the drum 12 in the extension direction via a connection part 16. The connection part 16 connects the drum 12 and the supply chute 14, and guides the materials to be crushed supplied from the supply chute 14 into the inside of the drum 12. The connection part 16 may be formed in a cylindrical shape so that the diameter increases toward the drum 12.

[0024] The supply chute 14 is formed in a cylindrical shape. The supply chute 14 is formed in a cylindrical shape or a square tubular shape with a square cross section. The inlet of the supply chute 14 faces upward (for example, vertically upward), and the opening at the end of the supply chute 14 connected to the connection part 16 faces the horizontal direction (drum 12). In a side view, the supply chute 14 may extend in a curved shape from one end where the inlet is provided to the other end connected to the connection part 16. Unlike the example shown in FIG. 1, the supply chute 14 may extend in a straight line obliquely downward from one end where the inlet is provided to the other end connected to the connection part 16 in a side view.

[0025] The dust collection fan 22 is a fan that exhausts gas from the space inside the mill apparatus 10. The dust collection fan 22 exhausts the gas inside the mill apparatus 10 to the outside of the mill apparatus 10 so that the inside of the mill apparatus 10 becomes negative pressure. The dust collection device 24 is a device (e.g., a filter) that collects fine powder from the gas exhausted by the dust collection fan 22. The dust collection fan 22 and the dust collection device 24 can collect fine powder (fine cement powder) floating in the space inside the mill apparatus 10.

[0026] The temperature measuring device 30 is a device that acquires information indicating the temperature inside the drum 12 of the mill apparatus 10 (hereinafter referred to as "temperature information"). The temperature measuring device 30 may acquire the temperature information by measuring the temperature of the space inside the drum 12. The temperature measuring device 30 may acquire a temperature that correlates with the temperature inside the drum 12 as the above-mentioned temperature information. The temperature of the cement discharged to the outlet (not shown) of the drum 12 correlates with the temperature inside the drum 12. Therefore, the temperature measuring device 30 may acquire the above-mentioned temperature information by measuring the temperature of the cement discharged to the outlet of the drum 12 (cement immediately after being discharged). The temperature of the outer surface of the drum 12 correlates with the temperature inside the drum 12. Therefore, the temperature measuring device 30 may acquire the above-mentioned temperature information by measuring the temperature of the outer surface of the drum 12. The temperature measuring device 30 outputs the acquired temperature information to the control device 100.

[0027] The cooling device 40 is a device that supplies a cooling liquid to the inside of the drum 12. As described above, the drum 12 is rotated around a horizontal axis to crush the object to be crushed. Accordingly, frictional heat is generated in each of the many crushing balls 18 in the drum 12 due to collision with the object to be crushed or the inner wall of the drum 12. The temperature inside the drum 12 increases due to the generation of frictional heat, so cooling by the cooling device 40 is required. In order to cool (to reduce the temperature) the inside of the drum 12, the cooling device 40 supplies a cooling liquid to the inside of the drum 12. The cooling device 40 may supply water (e.g., industrial water) as the cooling liquid. The water supplied by the cooling device 40 may be water at room temperature.

[0028] The cooling device 40 has a discharge part 42, a supply pipe 44, a liquid delivery device 50, a spray device 60, and a drive device 46. The discharge part 42 discharges the cooling liquid toward the inside of the drum 12. The discharge part 42 may be a nozzle capable of discharging the cooling liquid. The discharge part 42 may be disposed near the connection part with the connection part 16 of the supply chute 14 or within the connection part 16, and discharge the cooling liquid toward the inside of the drum 12. The supply pipe 44 is provided with the discharge part 42 at its tip, and is a pipe that guides the cooling liquid to the discharge part 42. The supply pipe 44 is provided so as to penetrate the side wall of the supply chute 14.

[0029] The liquid delivery device 50 is a device that delivers the cooling liquid to be discharged by the discharge part 42 to the supply pipe 44. The liquid delivery device 50 includes, for example, a liquid source 52, a delivery pipe 54, and a switching valve 56 (switching device). The liquid source 52 is a source of the cooling liquid. The delivery pipe 54 connects the liquid source 52 to a cooling liquid inlet provided in the supply pipe 44, and guides the cooling liquid from the liquid source 52 into the supply pipe 44.

[0030] The switching valve 56 switches between a state in which the discharge unit 42 discharges the cooling liquid and a state in which the discharge unit 42 does not discharge the cooling liquid. The switching valve 56 is provided in the delivery pipe 54, and switches between an open and closed state of the flow path in the delivery pipe 54 based on an operation command from the control device 100. For example, when the switching valve 56 is in an open state, the cooling liquid is introduced from the liquid delivery device 50 into the supply pipe 44, and the cooling liquid is discharged from the discharge unit 42. When the switching valve 56 is in a closed state, the introduction of the cooling liquid from the liquid delivery device 50 into the supply pipe 44 is stopped, and the discharge of the cooling liquid from the discharge unit 42 is stopped.

[0031] The injection device 60 is a device that injects compressed air (hereinafter simply referred to as "compressed air") into the supply pipe 44 so that the cooling liquid is discharged from the discharge portion 42. The compressed air injected by the injection device 60 is air whose volume has been reduced by increasing the pressure. The injection device 60 includes, for example, a supply source 62, a delivery pipe 64, and a switching valve 66. The supply source 62 is a supply source of compressed air, for example, an air compressor. The delivery pipe 64 connects the supply source 62 to a compressed air inlet provided in the supply pipe 44, and guides the compressed air from the supply source 62 into the supply pipe 44.

[0032] The switching valve 66 switches between a state in which compressed air is injected into the supply pipe 44 and a state in which compressed air is not injected into the supply pipe 44. The switching valve 66 is provided in the delivery pipe 64, and switches between an open and closed state of a flow path in the delivery pipe 64 based on an operation command from the control device 100. For example, when the switching valve 66 is in an open state, compressed air is introduced from the injection device 60 into the supply pipe 44, and at least a part of the cooling liquid present in the supply pipe 44 is discharged from the discharge part 42. When the switching valve 66 is in a closed state, the introduction of compressed air from the injection device 60 into the supply pipe 44 is stopped.

[0033] The drive device 46 is a device that moves the supply pipe 44 along the extension direction thereof. The drive device 46 includes a power source such as an air cylinder, and is connected to the supply pipe 44 via a connection member. The drive device 46 moves the supply pipe 44 between a position where the discharge unit 42 discharges the cooling liquid into the drum 12 and a position where the discharge unit 42 is retracted. The movement operation of the supply pipe 44 will be described later.

[0034] As shown in Fig. 2, the cooling device 40 has a sheath pipe 70. The sheath pipe 70 is a pipe formed in a cylindrical or rectangular tube shape (for example, a tube with a square cross section) and can accommodate the supply pipe 44 and the discharge part 42. The sheath pipe 70 is provided in the supply chute 14 so as to penetrate the side wall of the supply chute 14. The sheath pipe 70 is fixed to the side wall of the supply chute 14 via, for example, a fixing member. One end of the sheath pipe 70 is located inside the supply chute 14, and the other end of the sheath pipe 70 is located outside the supply chute 14.

[0035] Hereinafter, the space (area) inside the mill device 10 is referred to as the "internal space S1", and the space (area) outside the mill device 10 is referred to as the "external space S2". The internal space S1 of the mill device 10 includes the internal space of the supply chute 14, the internal space of the connection portion 16, and the internal space of the drum 12. The external space S2 is a space other than the area including the internal space S1 and the space inside the sheath tube 70. In addition, the end portion of the sheath tube 70 located in the internal space S1 (inside the supply chute 14) is referred to as the "tip portion 72", and the end portion of the sheath tube 70 located in the external space S2 is referred to as the "base end portion 74". The sheath tube 70 includes the tip portion 72 and the base end portion 74, and is provided in the supply chute 14 so that the tip portion 72 is located in the internal space S1 and the base end portion 74 is located in the external space S2.

[0036] The tip end 72 and the base end 74 are each open so that the internal space S1 and the external space S2 are connected via the space inside the sheath pipe 70. The end face located at the tip end 72 has an opening facing, for example, the connection part 16 or the drum 12, and the end face located at the base end 74 has an opening facing, for example, in a direction away from the connection part 16 or the drum 12. The supply pipe 44 is disposed in the space inside the sheath pipe 70, at least in a state in which the discharge part 42 discharges the cooling liquid. The inner diameter of the sheath pipe 70 is larger than the outer diameter (maximum width) of the discharge part 42 and the outer diameter (maximum width) of the supply pipe 44. The length of the sheath pipe 70 in the extension direction may be shorter than the length of the supply pipe 44 in the extension direction.

[0037] In a state in which the coolant is discharged from the discharge portion 42, the drive device 46 moves the supply pipe 44 to a position (hereinafter referred to as "discharge position P1") where the discharge portion 42 is disposed in the internal space S1 while protruding beyond the tip portion 72 of the sleeve pipe 70. In a state in which the supply pipe 44 has moved to the discharge position P1, the end of the supply pipe 44 where the discharge portion 42 is provided protrudes from the tip portion 72 of the sleeve pipe 70, and the end of the supply pipe 44 where the discharge portion 42 is not provided protrudes from the base end 74.

[0038] 3, when the coolant is not being discharged from the discharge portion 42, the drive device 46 moves the supply pipe 44 to a position (hereinafter referred to as the "retracted position P2") where the discharge portion 42 is disposed farther from the internal space S1 than the tip portion 72 of the sheath pipe 70. When the supply pipe 44 has moved to the retracted position P2, the tip side ends of the discharge portion 42 and the supply pipe 44 do not protrude from the tip portion 72 of the sheath pipe 70. When the supply pipe 44 has moved to the retracted position P2, the discharge portion 42 (its tip surface) may be housed within the sheath pipe 70.

[0039] When the supply pipe 44 has moved to the retracted position P2, the discharge portion 42 may be located in half of the range of the sheath pipe 70 close to the tip end 72, or the discharge portion 42 may be located in half of the range of the sheath pipe 70 close to the base end 74. The portion of the supply pipe 44 protruding from the base end 74 in the external space S2 is longer than when the supply pipe 44 is located at the discharge position P1. As described above, the drive device 46 moves the supply pipe 44 along the extension direction of the sheath pipe 70 between the discharge position P1 and the retracted position P2. Note that in Figures 2 and 3, etc., the extension direction of the sheath pipe 70 is indicated by "direction D1."

[0040] The sheath pipe 70 may be installed in a state inclined obliquely downward toward the inside (internal space S1) of the mill apparatus 10. In other words, the sheath pipe 70 may be installed so that the height position decreases from the base end 74 toward the tip end 72. In this case, the uppermost (lowest) part of the base end 74 is lower than the uppermost (lowest) part of the tip end 72. The extension direction (direction D1) of the sheath pipe 70 is inclined with respect to the horizontal direction. When the sheath pipe 70 is installed in an inclined state, the supply pipe 44 is also installed in an inclined state. The supply pipe 44 may be inclined obliquely downward toward the internal space S1.

[0041] 4(a) and 4(b) show an example of the tip 72 of the sheath tube 70. The tip 72 of the sheath tube 70 is formed with a pointed portion that protrudes toward the internal space S1. The pointed portion is formed in a region of the tip 72 close to one side edge when viewed from a specific direction (hereinafter referred to as the "specific direction") perpendicular to the extension direction of the sheath tube 70. When the sheath tube 70 is viewed from the specific direction, the pointed portion is formed at and in the vicinity of the intersection between the one side edge and a tip edge that extends from an end point of the side edge so as to intersect with the side edge at an angle (acute angle) smaller than 90°.

[0042] For example, an end face (hereinafter referred to as "tip face 72a") located at the tip portion 72 of the sheath tube 70 may intersect with the extending direction of the cylindrical sheath tube 70 in a state not perpendicular to the direction. The angle α between the tip face 72a (a virtual plane including the tip face 72a) and the extending direction of the sheath tube 70 may be 30° to 60°. In this case, as shown in FIG. 4(b), a pointed portion 72b having an angle α of 30° to 60° is formed. FIG. 4(b) shows one vertical cross section passing through the central axis Ax of the sheath tube 70, and this vertical cross section corresponds to the view seen from the specific direction. The vertical cross section shown in FIG. 4(b) is a view of the sheath tube 70 cut by a virtual plane including a portion of the tip face 72a that protrudes most toward the internal space S1, a portion that protrudes least toward the internal space S1 (furthest from the internal space S1), and the central axis Ax of the sheath tube 70.

[0043] By forming the pointed portion 72b, even if a cement lump is formed around the discharge portion 42 due to a reaction between the cement powder and the cooling liquid on the outer surface of the discharge portion 42, the lump can be removed by the pointed portion 72b. The above range of the angle α (30° to 60°) is set from the viewpoint of ensuring the strength of the pointed portion 72b and from the viewpoint of facilitating the removal of the cement lump. The minimum value of the angle α may be 32°, 35°, or 40° from the viewpoint of more reliably ensuring the strength of the pointed portion 72b. The maximum value of the angle α may be 58°, 55°, or 50° from the viewpoint of more easily removing the cement lump. In one example, the angle α may be 35° to 55°, or 40° to 50°.

[0044] When the sheath tube 70 is viewed from a direction (the specific direction) perpendicular to an imaginary plane including the portion of the tip surface 72a that protrudes most toward the internal space S1, the portion that protrudes least toward the internal space S1, and the central axis Ax, the pointed portion 72b has an angle α. When the sheath tube 70 is viewed from the specific direction, of a pair of side edges 72c, 72d of the sheath tube 70 along the direction D1, an end point of one side edge 72c on which the pointed portion 72b is formed is located closer to the drum 12 than an end point of the other side edge 72d.

[0045] 5 shows a schematic cross section of the inside of the supply chute 14 at a position where the top surface of the sleeve pipe 70 arranged in the supply chute 14 is visible. Here, a case where the supply chute 14 is formed in a cylindrical shape having a rectangular cross section will be described. The sleeve pipe 70 may be provided in the supply chute 14 such that the pointed portion 72b having the above-mentioned angle α at the tip portion 72 is located between the region through which the material to be crushed passes in the supply chute 14 (hereinafter referred to as "region R") and the supply pipe 44. Region R is, for example, a region through which 90% or more of the material to be crushed introduced into the supply chute 14 and guided to the inside of the drum 12 passes.

[0046] In the above configuration, the sleeve pipe 70 is disposed so that the tip surface 72a faces the opposite side to the region R. Here, the terms "left-right direction", "right direction" and "left direction" are used based on the view of the drum 12 from the supply chute 14 (viewed in the positive direction of the X-axis). The left-right direction corresponds to the Y-axis direction. FIG. 5 shows the right side wall 14a of the supply chute 14 located in the right direction (positive direction of the Y-axis) and the left side wall 14b of the supply chute 14 located in the left direction (negative direction of the Y-axis). The right side wall 14a and the left side wall 14b face each other in the left-right direction, sandwiching the region R and a portion of the sleeve pipe 70 located in the internal space S1 therebetween.

[0047] The sheath pipe 70 is disposed closer to the left side wall 14b so that the distance in the left-right direction between the central axis Ax of the sheath pipe 70 and the left side wall 14b is smaller than the distance in the left-right direction between the central axis Ax and the right side wall 14a. When the tip surface 72a faces the side opposite to the region R, the right side wall 14a, the region R, the pointed portion 72b, and the supply pipe 44 (or the central axis Ax of the sheath pipe 70) are arranged in this order in the left-right direction. Note that when the supply chute 14 is cylindrical, the rightmost portion of the peripheral wall of the supply chute 14, the region R, the pointed portion 72b, and the leftmost portion of the peripheral wall of the supply chute 14 may be arranged in this order.

[0048] 1, the control device 100 is a computer that controls at least the drive device 46, the liquid delivery device 50, the temperature measurement device 30, and the injection device 60. The control device 100 is configured to at least control the drive device 46 to move the supply pipe 44 to a discharge position P1 when discharging the cooling liquid from the discharge part 42, and to control the drive device 46 to move the supply pipe 44 to a retracted position P2 when stopping the discharge of the cooling liquid and retracting the discharge part 42.

[0049] The control device 100 has a circuit 110 as shown in Fig. 6. The circuit 110 includes at least one processor 112, a memory 114, a storage 116, an input / output port 118, and a timer 119. The storage 116 records programs for controlling various devices included in the crushing device 1. The storage 116 is a computer-readable recording medium such as a hard disk, a non-volatile semiconductor memory, a magnetic disk, an optical disk, or the like.

[0050] The memory 114 temporarily stores the program loaded from the storage 116, the calculation results of the processor 112, etc. The processor 112 executes the program in cooperation with the memory 114, thereby controlling each device included in the grinding device 1. The input / output port 118 inputs and outputs electric signals between the drive device 46, the liquid delivery device 50, the spray device 60, the temperature measurement device 30, etc., in response to a command from the processor 112. The timer 119 counts clock pulses at a predetermined cycle to measure the elapsed time in response to a command from the processor 112.

[0051] Cement can be manufactured in a cement manufacturing facility equipped with the above-mentioned pulverizing device 1. The cement manufacturing process (manufacturing method) executed in the cement manufacturing facility includes a clinker manufacturing process for manufacturing clinker (cement clinker) and a pulverizing process for pulverizing the clinker. The clinker manufacturing process includes a process for preheating and calcining the cement raw material, a process for generating clinker by burning the preheated and calcined cement raw material in a rotary kiln, and a process for cooling the clinker discharged from the rotary kiln in a clinker cooler.

[0052] In the above-mentioned grinding process, a process (finish grinding process) of grinding the object to be ground obtained by adding at least gypsum to clinker is performed using the grinding device 1, so that the clinker and gypsum are mixed while being ground to obtain cement. This grinding process includes a process of rotating the drum 12 of the mill device 10 to continue grinding the object to be ground, and a cooling process of supplying a cooling liquid into the drum 12 to cool the inside of the drum 12. This cooling process may be performed while the object to be ground is being continued to be ground.

[0053] The control device 100 controls the drive device 46, the liquid delivery device 50, the spray device 60, the temperature measurement device 30, and the like to perform the cooling process. FIG. 7 is a flow chart showing an example of a series of processes performed by the control device 100 in the cooling process. In this series of processes, the control device 100 executes step S11 in a state in which the material to be pulverized is supplied from the supply chute 14 into the inside of the drum 12 and the pulverization of the material to be pulverized by the rotation of the drum 12 is started. In the initial state, the supply pipe 44 is disposed at the retreat position P2. In step S11, for example, the control device 100 acquires temperature information indicating the temperature inside the drum 12 from the temperature measurement device 30. In the following steps, the supply of the material to be pulverized from the supply chute 14 and the rotation of the drum 12 are continued.

[0054] Next, the control device 100 executes step S12. In step S12, for example, the control device 100 determines whether or not the temperature indicated by the temperature information acquired in step S11 is higher than a predetermined set temperature. The predetermined set temperature is, for example, preset to a value lower than the temperature at which a portion of the gypsum contained in the material to be pulverized changes into gypsum hemihydrate. In one example, the set temperature is set to about 70°C to 80°C. In step S12, if the temperature indicated by the temperature information acquired in step S11 is equal to or lower than the set temperature (step S12: NO), the process executed by the control device 100 returns to step S11.

[0055] On the other hand, in step S12, if the temperature indicated by the temperature information acquired in step S11 is higher than the set temperature (step S12: YES), the process executed by the control device 100 proceeds to step S13. Thus, while the temperature indicated by the temperature information acquired in step S12 is equal to or lower than the set temperature, the control device 100 repeats steps S11 and S12. In this case, the control device 100 may repeat steps S11 and S12 at a predetermined cycle. In step S13, for example, the control device 100 moves the supply pipe 44 from the retreat position P2 to the discharge position P1 along the direction D1 by the drive device 46. As a result, the discharge part 42 is disposed at a position in the internal space S1 where the cooling liquid can be discharged into the drum 12.

[0056] Next, the control device 100 executes step S14. In step S14, for example, the control device 100 transitions the switching valve 56 of the liquid delivery device 50 from a closed state to an open state. When the switching valve 56 transitions to the open state, the discharge of the cooling liquid from the discharge part 42 in the internal space S1 is started.

[0057] Next, the control device 100 executes steps S15 and S16. In step S15, for example, similar to step S11, the control device 100 acquires temperature information indicating the temperature inside the drum 12 from the temperature measuring device 30. In step S16, for example, the control device 100 determines whether the temperature indicated by the temperature information acquired in step S15 is below a predetermined set temperature. The set temperature used for the determination in step S16 may be predetermined to be the same value as or smaller than the set temperature used for the determination in step S12. In step S16, if the temperature indicated by the temperature information acquired in step S15 is equal to or higher than the set temperature (step S16: NO), the process executed by the control device 100 returns to step S15.

[0058] On the other hand, in step S16, if the temperature indicated by the temperature information acquired in step S15 is lower than the set temperature (step S16: YES), the process executed by the control device 100 proceeds to step S17. Thus, while the temperature indicated by the temperature information acquired in step S15 is equal to or higher than the set temperature, the control device 100 repeats steps S15 and S16. In this case, the control device 100 may repeat steps S15 and S16 at a predetermined cycle. In step S17, for example, the control device 100 transitions the switching valve 56 of the liquid delivery device 50 from an open state to a closed state. The transition of the switching valve 56 to a closed state stops the discharge of the cooling liquid from the discharge part 42 located in the internal space S1.

[0059] Next, the control device 100 executes step S18. In step S18, for example, the control device 100 controls the injection device 60 to inject compressed air (compressed air) into the supply pipe 44. In one example, the control device 100 operates a device that serves as the supply source 62 of the injection device 60, and transitions the switching valve 66 of the injection device 60 from a closed state to an open state, thereby injecting (supplying) the compressed air into the supply pipe 44. Then, after a predetermined time has elapsed since the start of injection, the control device 100 transitions the switching valve 66 from an open state to a closed state. This injection of compressed air can discharge the cooling liquid remaining in the supply pipe 44 after the stop in step S17 from the discharge part 42.

[0060] Next, the control device 100 executes step S19. In step S19, for example, the control device 100 moves the supply pipe 44 from the discharge position P1 to the retracted position P2 along the direction D1 by the drive device 46. This causes the discharge section 42 to be housed (retracted) within the sleeve pipe 70. After executing step S19, the control device 100 repeats a series of processes from step S11 onwards. For example, the control device 100 repeatedly executes a series of processes from step S11 onwards until the pulverizing device 1 stops operating.

[0061] In the above series of processes, when the temperature indicated by the temperature information acquired from the temperature measuring device 30 exceeds a predetermined set temperature (threshold), the control device 100 executes the following: moving the supply pipe 44 to the discharge position P1 by the drive device 46, and controlling the switching valve 56 to discharge the cooling liquid from the discharge unit 42 with the supply pipe 44 located at the discharge position P1. When the temperature indicated by the temperature information acquired from the temperature measuring device 30 falls below a predetermined set temperature (threshold), the control device 100 executes the following: controlling the switching valve 56 to stop the discharge of the cooling liquid from the discharge unit 42, and moving the supply pipe 44 to the retracted position P2 by the drive device 46.

[0062] In the above series of processes, the control device 100 executes the control of the injection device 60 to inject compressed air into the supply pipe 44 in a state where the supply pipe 44 is disposed at the discharge position P1. Then, after the compressed air is injected into the supply pipe 44, the control device 100 executes the control of the drive device 46 to move the supply pipe 44 to the retracted position P2 in a state where the discharge part 42 is not discharging the cooling liquid.

[0063] The above-mentioned series of processes is an example and can be modified as appropriate. In the above-mentioned series of processes, the control device 100 may execute one step and the next step in parallel, or may execute each step in an order different from the above-mentioned example. The control device 100 may omit any step, or may execute a process different from the above-mentioned example in any step. The control device 100 may omit, for example, step S18. In this case, the pulverizing device 1 may not be equipped with the injection device 60.

[0064] Next, a crushing device 1 according to a modified example will be described with reference to Fig. 8 to Fig. 10. As shown in Fig. 8, the crushing device 1 according to the modified example includes a cooling device 40A instead of the cooling device 40. Note that in Fig. 8, the mill device 10 is omitted, and the boundary BL between the internal space S1 and the external space S2 is indicated by a dashed line. This boundary BL corresponds to the side wall of the supply chute 14.

[0065] In the cooling device 40A, when the supply piping 44 is disposed at the retracted position P2, the discharge section 42 (the entire discharge section 42) is not located inside the sleeve pipe 70, but is located in the external space S2 outside the mill apparatus 10, protruding from the base end section 74. The drive device 46 of the cooling device 40A is configured to be able to move the supply piping 44 along the direction D1 between the discharge position P1 where the discharge section 42 is disposed in the internal space S1 and the retracted position P2 where the discharge section 42 is disposed in the external space S2.

[0066] The cooling device 40A has a second injection device 80. In this case, the cooling device 40A has two types of injection devices, the injection device 60 (first injection device) and the second injection device 80. While the injection device 60 injects compressed air into the supply pipe 44, the second injection device 80 injects compressed air to the outer surface of the discharge part 42 when the supply pipe 44 is retracted to the retracted position P2 and the discharge part 42 is located in the external space S2. The second injection device 80, like the injection device 60, can be switched between a state in which compressed air is injected and a state in which compressed air is not injected in response to an operation command from the control device 100.

[0067] Fig. 9 is a flowchart showing an example of a series of processes executed by the control device 100 when the cooling device 40A is provided. In this series of processes, the control device 100 executes steps S21 to S28 similarly to steps S11 to S18 shown in Fig. 7. After compressed air is injected into the supply pipe 44 in step S28, the control device 100 executes step S29. In step S29, for example, the control device 100 moves the supply pipe 44 by the drive device 46 along the direction D1 from the discharge position P1 to the retracted position P2 so that the discharge part 42 is disposed in the external space S2 that is outside the internal space S1 and the space inside the sheath pipe 70.

[0068] Next, the control device 100 executes step S30. In step S30, for example, the control device 100 controls the second injection device 80 so that compressed air is injected onto the outer surface of the discharge part 42 disposed in the external space S2. The injection of compressed air from the second injection device 80 can remove the cooling liquid adhering to the outer surface of the discharge part 42 after the discharge of the cooling liquid in step S27 is stopped from the outer surface of the discharge part 42.

[0069] The control device 100 may start discharging the cooling liquid from the discharge unit 42 while injecting compressed air into the supply pipe 44 with the injection device 60. The control device 100 may stop discharging the cooling liquid from the discharge unit 42 while injecting compressed air into the supply pipe 44 with the injection device 60. FIG. 10 is a flowchart showing an example of a series of processes including the above controls. The control device 100 executes steps S41 to S43 similarly to steps S11 to S13 shown in FIG. 7.

[0070] Next, the control device 100 executes steps S44 and S45. In step S44, for example, the control device 100 changes the switching valve 66 of the injection device 60 from a closed state to an open state in a state in which the supply pipe 44 is disposed at the discharge position P1 so that the discharge part 42 is located in the internal space S1. This starts the injection of compressed air from the injection device 60 into the supply pipe 44. In step S45, for example, the control device 100 changes the switching valve 56 of the liquid delivery device 50 from a closed state to an open state. This starts the discharge of the cooling liquid from the discharge part 42 in a state in which the injection of compressed air from the injection device 60 is continued.

[0071] Next, the control device 100 executes step S46. In step S46, for example, the control device 100 transitions the switching valve 66 of the injection device 60 from an open state to a closed state. This stops the injection of compressed air into the supply pipe 44 while the discharge of the cooling liquid from the discharge part 42 continues. Next, the control device 100 executes steps S47 and S48, similar to steps S15 and S16 shown in FIG. 7.

[0072] In step S48, if the temperature indicated by the temperature information acquired in step S47 is lower than the set temperature (step S48: YES), the control device 100 executes steps S49 and S50. In step S49, for example, the control device 100 transitions the switching valve 66 of the injection device 60 from an open state to a closed state while the injection of the cooling liquid from the injection unit 42 continues. This starts the injection of compressed air from the injection device 60 into the supply pipe 44. In step S50, for example, the control device 100 transitions the switching valve 56 of the liquid delivery device 50 from an open state to a closed state. This stops the injection of the cooling liquid from the injection unit 42 while the injection of compressed air from the injection device 60 continues.

[0073] Next, the control device 100 executes step S51. In step S51, for example, the control device 100 transitions the switching valve 66 of the injection device 60 from an open state to a closed state. As a result, after the discharge of the cooling liquid from the discharge part 42 stops, the injection of the compressed air into the supply pipe 44 stops. Next, the control device 100 executes steps S52 and S53. In step S52, for example, the control device 100 moves the supply pipe 44 along the direction D1 from the discharge position P1 to the retreat position P2 by the drive device 46 so that the discharge part 42 is disposed in the external space S2. In step S53, for example, the control device 100 controls the second injection device 80 so that the compressed air is injected onto the outer surface of the discharge part 42 disposed in the external space S2.

[0074] Immediately after the start and immediately before the stop of the discharge of the cooling liquid, the pressure of the cooling liquid sent into the supply pipe 44 becomes weak, and the cooling liquid may drip onto the outer surface of the discharge part 42 instead of splashing out from the discharge part 42. In contrast, in the series of processes exemplified above, the discharge of the cooling liquid from the discharge part 42 is started and stopped while compressed air is injected into the supply pipe 44. Therefore, immediately after the start and immediately before the stop of the discharge of the cooling liquid, the cooling liquid is discharged (discharged) together with the compressed air from the discharge part 42. As a result, the cooling liquid is less likely to adhere to the outer surface of the discharge part 42.

[0075] The control device 100 may switch between the discharge state and the stop state based on information other than the temperature information acquired from the temperature measuring device 30. For example, the control device 100 may control the liquid delivery device 50 to move the supply pipe 44 to the discharge position P1 by the drive device 46 based on input information indicating an instruction from an operator to start discharge, and to discharge the cooling liquid from the discharge unit 42. The control device 100 may control the liquid delivery device 50 to stop the discharge of the cooling liquid from the discharge unit 42 based on input information indicating an instruction from an operator to stop discharge, and to move the supply pipe 44 to the retreat position P2 by the drive device 46. In this case, the control device 100 may output the above temperature information to a monitor that displays information to the operator.

[0076] While the mill apparatus 10 is in operation (while the mill apparatus 10 continues to grind the material to be ground), the control device 100 may cause the drive device 46 to maintain the state in which the discharge part 42 is disposed in the internal space S1, regardless of whether or not the cooling liquid is being discharged from the discharge part 42. When the operation of the mill apparatus 10 is stopped, the control device 100 may cause the drive device 46 to move the supply pipe 44 from the discharge position P1 to the retracted position P2.

[0077] The shape of the sheath tube 70 is not limited to the above-mentioned example. In the above-mentioned example, when the sheath tube 70 is viewed from a specific direction, the tip surface 72a is formed in a straight line from the tip of one side edge 72c to the tip of the other side edge 72d, but the tip surface may be curved to form a pointed portion. In addition, the tip surface may be composed of two or more planes extending at different angles, and a pointed portion may be formed by one plane (a part of the tip surface). In the tip portion 72 of the sheath tube 70, the tip surface may be perpendicular to the extension direction of the sheath tube 70. In this case, the tip portion 72 may not be formed with a pointed portion.

[0078] In the above example, the discharge part 42 (nozzle) is provided at the tip of the supply pipe 44, but the supply pipe 44 and the discharge part 42 may be configured as one unit. For example, a plurality of discharge ports connecting the inside and outside of the supply pipe 44 may be formed at (and in the vicinity of) the tip of the supply pipe 44. In this case, the portion of the supply pipe 44 where the plurality of discharge ports are formed constitutes the discharge part.

[0079] [Effects of the embodiment] As a device for lowering the temperature inside the mill apparatus 10, a cooling device having a discharge part and a supply pipe installed in a fixed position is considered. In the mill apparatus 10 for grinding cement, cement powder floats. Therefore, after the cooling liquid from the discharge part whose position is fixed is stopped, the cooling liquid adhering to the discharge part and the cement powder may react with each other, and a cement lump may be generated around the discharge part. If a cement lump is formed in the discharge part, the discharge part and the supply pipe may break down due to the weight of the lump. In addition, regular maintenance is required to remove such a lump. In the maintenance, for example, an operator performs an operation to remove the cement lump formed around the discharge part in the mill apparatus 10.

[0080] In contrast, in the above-mentioned pulverizing device 1, the supply pipe 44 that guides the cooling liquid to the discharge part 42 can be moved between the discharge position P1 and the retreat position P2 where the discharge part 42 is farther away from the inside (internal space S1) of the mill device 10 than the tip part 72 of the sleeve pipe 70. Therefore, when the cooling liquid from the discharge part 42 is stopped, the discharge part 42 can be retreated from the inside of the mill device 10, so that cement lumps are unlikely to be generated around the discharge part 42. Therefore, it is useful for suppressing the influence of the cement powder on the cooling device 40. As a result, the occurrence of failures of the discharge part 42 and the supply pipe 44 due to cement lumps can be suppressed, and the maintenance work of the cooling device 40 by the workers can be simplified.

[0081] In the above-described pulverizing device 1, the tip end 72 and the base end 74 may be open so that the inside (internal space S1) and the outside (external space S2) of the mill device 10 are connected via the space in the sheath pipe 70. In this configuration, for example, when gas inside the mill device 10 is sucked by the dust collection fan 22, air is taken into the inside of the mill device 10 from the outside through the space between the sheath pipe 70 and the supply pipe 44. This air flow can suppress the generation of stagnation in the space between the sheath pipe 70 and the supply pipe 44. Therefore, it is useful for improving the maintainability of the cooling device 40.

[0082] In the above-described pulverizing device 1, the sleeve pipe 70 may be inclined obliquely downward toward the inside (internal space S1) of the mill device 10. In this case, it is possible to suppress the release of cement powder or lumps from the inside of the mill device 10 without providing a backflow prevention device inside the sleeve pipe 70. Therefore, it is useful for simplifying the configuration of the cooling device 40.

[0083] In the above-described pulverizing device 1, the tip 72 of the sheath pipe 70 may be formed with a pointed portion 72b that protrudes toward the inside (internal space S1) of the mill device 10. In this case, even if a lump of cement larger than the outer diameter of the sheath pipe 70 is formed around the discharge portion 42 during the supply of the cooling liquid, the lump can be broken and removed by the pointed portion 72b of the sheath pipe 70 when the supply piping 44 is moved so that the discharge portion 42 is accommodated within the sheath pipe 70. This is therefore useful for improving the maintainability of the cooling device 40.

[0084] In the above-described pulverization device 1, the tip 72 of the sheath pipe 70 may be formed with a tip surface 72a extending crosswise with respect to the extension direction (direction D1) of the sheath pipe 70 so as to form a pointed portion 72b. The angle between the tip surface 72a and the extension direction of the sheath pipe 70 may be 30° to 60°. In this case, when the supply pipe 44 is moved so that the discharge portion 42 is accommodated in the sheath pipe 70, a force can be applied from the sheath pipe 70 to one point of a lump of cement that may be formed in the discharge portion 42, and the lump can be easily removed. This is therefore useful for improving the maintainability of the cooling device 40.

[0085] In the above-described crushing device 1, the sleeve pipe 70 may be provided in the supply chute 14 such that the pointed portion 72b is located between the region R through which the material to be crushed passes in the supply chute 14 and the supply pipe 44. In this case, the material to be crushed passing through the supply chute 14 is less likely to enter the inside of the sleeve pipe 70, and the generation of stagnation in the sleeve pipe 70 is suppressed. This is therefore useful for improving the maintainability of the cooling device 40.

[0086] The above-described pulverizing device 1 may further include a switching device (switching valve 56) for switching between a state in which the discharge unit 42 discharges the cooling liquid and a state in which the discharge unit 42 does not discharge the cooling liquid, a temperature measuring device 30 for acquiring temperature information indicating the temperature inside the drum 12, and a control device 100 for controlling the driving device 46, the switching device, and the temperature measuring device 30. When the temperature indicated by the temperature information exceeds a predetermined set temperature, the control device 100 executes the following: moving the supply pipe 44 to the discharge position P1 by the driving device 46, and controlling the switching device so that the cooling liquid is discharged from the discharge unit 42 with the supply pipe 44 disposed at the discharge position P1. When the temperature indicated by the temperature information falls below the predetermined set temperature, the control device 100 executes the following: controlling the switching device to stop the discharge of the cooling liquid from the discharge unit 42, and moving the supply pipe 44 to the retracted position P2 by the driving device 46. In this case, the generation of cement lumps at the discharge unit 42 can be suppressed while the cooling liquid is efficiently supplied into the mill device 10. Therefore, it is useful for efficient cooling of the inside of the mill apparatus 10 and for improving the maintainability of the cooling device 40.

[0087] The above-described pulverizing device 1 may further include an injection device 60 that injects compressed air into the supply pipe 44 so that the cooling liquid is discharged from the discharge part 42. In this case, the cooling liquid in the supply pipe 44 can be discharged from the discharge part 42, so that it is possible to prevent the formation of cement lumps in the discharge part 42 due to the cooling liquid remaining in the supply pipe 44. Therefore, it is useful for preventing the influence on the cooling device 40 caused by the reaction between the cooling liquid and the cement powder when the discharge is stopped.

[0088] The above-described pulverizing device 1 may further include a control device 100 for controlling the driving device 46 and the injection device 60. The control device 100 executes the injection device 60 to inject compressed air into the supply pipe 44 in a state in which the supply pipe 44 is disposed at the discharge position P1. After the compressed air is injected into the supply pipe 44, the control device 100 executes the drive device 46 to move the supply pipe 44 to the retreat position P2 in a state in which the discharge unit 42 is not discharging the cooling liquid. In this case, the cooling liquid in the supply pipe 44 is discharged in a state in which the discharge unit 42 is disposed inside the mill device 10. Therefore, the discharged cooling liquid is not sprayed to areas other than the inside of the mill device 10. Therefore, it is useful for reducing the influence of the cooling liquid discharged in association with the injection of compressed air into the supply pipe 44 while suppressing the generation of cement lumps in the discharge unit 42. [Explanation of symbols]

[0089] 1...grinding device, 10...mill device, 12...drum, 14...supply chute, 18...grinding ball, 30...temperature measuring device, 42...discharge section, 44...supply piping, 46...driving device, 50...liquid delivery device, 56...switching valve, 60...injection device, 70...sheath tube, 72...tip portion, 72a...tip surface, 72b...pointed portion, 74...base end portion, 100...control device, P1...discharge position, P2...retraction position.

Claims

1. a mill device including a drum that accommodates a plurality of grinding balls and is rotatable about a predetermined axis, and a feed chute that feeds materials to be ground, including cement clinker, into the inside of the drum, and which grinds the materials by rotating the drum; a cooling device that supplies a cooling liquid to the inside of the drum, The cooling device includes: a sleeve pipe including a tip end and a base end, the tip end being located inside the mill apparatus and the base end being located outside the mill apparatus, the sleeve pipe being provided on the supply chute such that the tip end is located inside the mill apparatus and the base end is located outside the mill apparatus; a supply pipe disposed in the sheath pipe and directing the cooling liquid to a discharge portion provided at a tip of the sheath pipe; a drive device that moves the supply pipe along an extension direction of the sheath pipe between a discharge position where the discharge portion is disposed inside the mill device in a state where it protrudes beyond the tip portion of the sheath pipe and a retracted position where the discharge portion is disposed so as to be farther away from the inside of the mill device than the tip portion, A crushing device, wherein the tip of the sleeve pipe is formed with a pointed portion protruding toward the inside of the mill device.

2. The crushing device according to claim 1 , wherein the tip end and the base end are open so that the inside and the outside of the mill device are connected via a space within the sleeve pipe.

3. The crushing device according to claim 1 or 2, wherein the sleeve pipe is inclined obliquely downward toward the inside of the mill device.

4. a tip surface is formed at the tip portion of the sleeve pipe, the tip surface extending intersecting with an extension direction of the sleeve pipe so as to form the pointed portion, The crushing device according to any one of claims 1 to 3, wherein an angle between the tip surface and an extension direction of the sleeve pipe is 30° to 60°.

5. The crushing device according to any one of claims 1 to 4, wherein the sleeve pipe is provided in the supply chute such that the pointed portion is located between an area in the supply chute through which the material to be crushed passes and the supply piping.

6. a switching device that switches between a state in which the discharge portion discharges the cooling liquid and a state in which the discharge portion does not discharge the cooling liquid; a temperature measuring device for acquiring temperature information indicative of a temperature inside the drum; a control device that controls the driving device, the switching device, and the temperature measuring device, The control device includes: when the temperature indicated by the temperature information exceeds a predetermined set temperature, the drive device moves the supply pipe to the discharge position, and the switching device is controlled so as to discharge the cooling liquid from the discharge portion with the supply pipe disposed at the discharge position; The crushing device according to any one of claims 1 to 5, wherein, when the temperature indicated by the temperature information falls below a predetermined set temperature, the switching device is controlled to stop the discharge of the cooling liquid from the discharge portion, and the drive device is caused to move the supply pipe to the retracted position.

7. The crushing device according to any one of claims 1 to 5, further comprising an injection device that injects compressed air into the supply pipe so that the cooling liquid is discharged from the discharge portion.

Images