Method for starting resin particle manufacturing device, method for manufacturing resin particle, and resin particle manufacturing device

Abstract

The invention provides a method for starting a resin pellet manufacturing apparatus, a method for manufacturing resin pellets, and a resin pellet manufacturing apparatus. The present invention addresses the problem of reducing the amount of particulate cooling water discarded. A method for starting a pellet production device (1) is provided with: a water supply step for filling a water chamber (30) with pellet cooling feed water (PCW) stored in a water tank (50) by supplying the water chamber (30) with the pellet cooling feed water using a pump (60) before starting production of resin pellets, and then stopping the supply of the pellet cooling feed water, and supplying the pellet cooling feed water to the water chamber (30) by stopping the supply of the pellet cooling feed water; the water level of the particle cooling feed water is set to a target water level (TL) at a position lower than the upper end portion (163) of the return path (200).

Description

Technical Field

[0001] The present invention relates to a method for starting a resin pellet manufacturing device, a method for manufacturing resin pellets, and a resin pellet manufacturing device. Background Art

[0002] In the past, there is known a pellet manufacturing device for manufacturing resin pellets. For example, in Patent Document 1, a granulating device (granulating device) is disclosed, which includes a PCW (PELLET COOLING / TRANSPORT WATER; pellet cooling / transport water) tank (water tank), an outgoing path, a circulation box (water chamber) and a return path. In this technology, a circulation flow path is formed, and the circulation flow path allows the pellet cooling transport water (pellet cooling water) flowing from the PCW box to the circulation box via the outgoing path to flow from the circulation box to the PCW box via the return path. The return path connects the circulation box to the PCW via the top of the circulation box. The granulating device also includes: a mold (mold plate) having a mold hole (mold hole) arranged facing the water chamber; and a cutting knife (cutter) arranged in the circulation box to cut the molten resin ejected from the mold hole to manufacture resin pellets.

[0003] The granulation device heats the mold by flowing a heat medium into the mold before starting to produce resin pellets. In this state, after the pellet cooling and transporting water circulates in the aforementioned circulation flow path, the circulation is stopped, and the pellet cooling and transporting water is discharged from the circulation box and a predetermined amount of pellet cooling and transporting water is stored in the circulation box. Then, the pellet cooling and transporting water stored in the circulation box is heat-exchanged with the mold to heat the pellet cooling and transporting water.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2011-240494 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In the technology described in Patent Document 1, it is uneconomical because the particle cooling conveying water is discharged from the circulation box to the outside of the circulation flow path in order to lower the water level of the particle cooling conveying water. In detail, in the above-mentioned granulation device, after the particle cooling conveying water is circulated, the circulation is stopped so that the circulation box is filled with the particle cooling conveying water. However, at the time of stopping the circulation, the particle cooling conveying water accumulates at the upper end of the outward path, and the water level of the particle cooling conveying water is high. Due to the height of the water level, the excess water pressure acts on the inside of the circulation box, thereby, there is a possibility that the resin existing in the inside of the die hole is pushed back and the particle cooling conveying water invades the inside of the die hole. Therefore, in the above-mentioned granulation device, the water level of the particle cooling conveying water is lowered by discharging the particle cooling conveying water from the circulation box to the outside of the circulation flow path. However, the particle cooling conveying water discharged to the outside of the circulation flow path is generally discarded, so discharging the particle cooling conveying water to the outside of the circulation flow path in order to lower the water level will increase the amount of waste, which is uneconomical.

[0009] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to reduce the amount of waste pellet cooling water.

[0010] Means used to solve problems

[0011] A method for starting a resin pellet manufacturing device according to one embodiment of the present invention comprises: a circulation flow path having an outward path for pellet cooling water ejected from a water tank by a pump to reach a water chamber and a return path for the pellet cooling water to reach the water tank from the water chamber via the upper side of the water chamber; a die plate having a plurality of die holes and arranged facing the water chamber; and a cutter arranged in the water chamber to cut the molten resin ejected from the plurality of die holes to manufacture resin pellets; while cooling the manufactured resin pellets with the pellet cooling water flowing in the circulation flow path, the resin pellets are conveyed from the water chamber; the method for starting the resin pellet manufacturing device comprises: a water supply step, before starting the manufacture of the resin pellets, supplying the pellet cooling water stored in the water tank to the water chamber by the pump to fill the water chamber, and then stopping the supply of the pellet cooling water so that the water level of the pellet cooling water becomes a target water level set at a position lower than the upper end of the return path.

[0012] According to this configuration, the supply of the particle cooling water is stopped in accordance with the target water level during the water supply process, so that the amount of particle cooling water discarded can be reduced compared to the case where the particle cooling water is discharged after circulating in the circulation flow path to set the particle cooling water surface to the target water level.

[0013] In the above-mentioned configuration, in the water supply step, water may be supplied to the water chamber while returning a part of the particle cooling water ejected from the water tank by the pump to the water tank.

[0014] According to this structure, in the water supply process, part of the particle cooling water returns to the water tank, and the remaining particle cooling water is supplied to the water chamber. As a result, the flow rate of the particle cooling water flowing into the water chamber can be reduced compared to the case where part of the particle cooling water is not returned to the water tank. As a result, since the speed at which the particle cooling water accumulates in the water chamber becomes relatively slow, it becomes easy to stop the water supply when the water level of the particle cooling water corresponds to the target water level.

[0015] In the above configuration, in the water supply step, the particle cooling water may be supplied to the water chamber via an auxiliary flow path having an inner diameter smaller than that of the outward flow path and arranged in parallel with at least a portion of the outward flow path.

[0016] According to this configuration, in the water supply process, the particle cooling water is supplied to the water chamber via the auxiliary flow path having an inner diameter smaller than that of the outgoing flow path, so that the flow rate of the particle cooling water flowing into the water chamber can be reduced compared to the case where water is supplied exclusively via the outgoing flow path. As a result, the speed at which the particle cooling water accumulates in the water chamber becomes relatively slow, so it becomes easy to stop the water supply when the water surface of the particle cooling water corresponds to the target water level.

[0017] In the above structure, it is also possible to further include: a rotation process, which is performed at least after the aforementioned water supply process, and the cutter is rotated while the aforementioned cutter is in contact with the aforementioned mold plate; in the aforementioned rotation process, the aforementioned cutter is rotated while the aforementioned particle cooling water is supplied to the aforementioned water chamber via the aforementioned auxiliary flow path.

[0018] In the rotating step, the temperature of the mold plate may excessively rise due to frictional heat generated by the rotation of the cutter in contact with the mold plate. In contrast, according to the above configuration, the temperature of the mold plate can be controlled by supplying particle cooling water from the auxiliary flow path.

[0019] In the above configuration, in the rotating step, the particle-cooling water may be discharged through a discharge flow path that connects the water chamber with the outside of the water chamber while the particle-cooling water is supplied to the water chamber.

[0020] According to this structure, the particle cooling water in the water chamber can be replaced while the particle cooling water in the water chamber is stirred by the cutter rotating in the water chamber. Thus, local boiling in the water chamber can be suppressed. As a result, the temperature of the surface of the mold plate facing the water chamber is kept uniform.

[0021] Furthermore, according to the above configuration, the resin dripping from the die holes of the die plate and picked up by the cutter can be discharged to the outside of the water chamber together with the granular cooling water discharged from the water chamber.

[0022] In the above configuration, in the rotating step, the amount of the particle cooling water discharged through the discharge flow path may be adjusted so that the position of the water surface of the particle cooling water in the water chamber is maintained at the target water level.

[0023] According to this configuration, in the rotation step, it is possible to suppress the water surface of the particle cooling water from being positioned at a water level deviating from the target water level.

[0024] In the above-mentioned structure, it is also possible that, in the above-mentioned water supply process, the above-mentioned particle cooling water is supplied to the above-mentioned water chamber by setting the flow path switching mechanism, which is arranged on the downstream side of the above-mentioned pump in the above-mentioned forward path and can switch between the first state, the second state and the third state, to the above-mentioned first state, wherein the first state is a state in which both the above-mentioned water chamber and the above-mentioned water tank are set as the delivery destination of the above-mentioned particle cooling water, the second state is a state in which one of the above-mentioned water chamber and the above-mentioned water tank is set as the delivery destination of the above-mentioned particle cooling water, and the third state is a state in which the other of the above-mentioned water chamber and the above-mentioned water tank is set as the delivery destination of the above-mentioned particle cooling water.

[0025] According to the present structure, since the flow path switching mechanism becomes the first state in the water supply process, a part of the particle cooling water returns to the water tank, and the remaining particle cooling water is supplied to the water chamber. As a result, the flow rate of the particle cooling water flowing into the water chamber can be reduced compared to the case where a part of the particle cooling water is not sent back to the water tank. In addition, when there is a need to circulate the particle cooling water, it is sufficient to switch the flow path switching mechanism to the second state and set the delivery destination of the particle cooling water to the water chamber. Furthermore, when there is a need to switch the delivery destination of the particle cooling water to the water tank, it is sufficient to set the flow path switching mechanism to the third state. In this way, by having a flow path switching mechanism, it becomes easy to switch the delivery destination of the particle cooling water according to the purpose.

[0026] In the above structure, the return path may also include: an upper connecting flow path connected to the upper part of the water chamber and extending upward; and an inclined flow path, including a lower end connected to the upper connecting flow path, inclined in a manner with the front end rising from the lower end to the upper end reaching the return path; in the water supply process, the target water level is set at a position lower than the lower end.

[0027] According to this configuration, since the target water level is set at a position lower than the lower end of the inclined flow path, the water pressure acting in the water chamber can be suppressed compared to the case where the target water level is set at a position higher than the lower end. As a result, it is possible to efficiently suppress the resin existing inside the plurality of mold holes of the mold plate from being pushed back and the granular cooling water from intruding into the plurality of mold holes.

[0028] Furthermore, since it is not necessary to discharge the particle cooling water in the inclined flow path, the amount of waste particle cooling water can be reduced.

[0029] A method for manufacturing resin pellets according to another embodiment of the present invention is a method for manufacturing resin pellets in a resin pellet manufacturing device having a circulation flow path, wherein the circulation flow path has an outward path for allowing pellet cooling water ejected from a water tank by a pump to reach a water chamber and a return path for allowing the pellet cooling water to reach the water tank from the water chamber via the upper side of the water chamber; the method for manufacturing the resin pellets comprises: a water supply step, in which the pellet cooling water stored in the water tank is supplied to the water chamber before the manufacture of the resin pellets is started; a rotation step, in which a cutter arranged in the water chamber is rotated in a state in which the cutter is in contact with a mold plate having a plurality of mold holes facing the water chamber; a heating step, in which the mold plate is heated to melt the resin present in the plurality of mold holes; a material A material supplying step of supplying resin material to the mold plate from upstream; a manufacturing step of cutting the molten resin ejected from the plurality of mold holes of the mold plate with the cutter in the water chamber to manufacture the resin pellets, and conveying the resin pellets from the water chamber while cooling the resin pellets with the pellet cooling water, thereby manufacturing the resin pellets; and an operation stopping step of stopping the heating of the mold plate and stopping the operation of the resin pellet manufacturing device in a state where the molten resin exists inside the plurality of mold holes; in the water supplying step, after the water chamber is filled with the pellet cooling water, the supply of the pellet cooling water is stopped so that the water level of the pellet cooling water becomes a target water level set at a position lower than the upper end of the return path.

[0030] According to this configuration, the supply of the particle cooling water is stopped in accordance with the target water level during the water supply process, so that the amount of particle cooling water discarded can be reduced compared to the case where the particle cooling water is discharged after circulating in the circulation flow path to set the particle cooling water surface to the target water level.

[0031] In the above configuration, in the rotating step, the water level of the particle cooling water may be maintained at the target water level, and the rotation speed of the cutter may be set to be lower than the rotation speed of the cutter in the manufacturing step.

[0032] When the water level of the particle cooling water is maintained at the target water level, the water pressure acting on the water chamber is suppressed, but there is a possibility of cavitation as the cutter rotates. In contrast, according to this structure, since the rotation speed of the cutter is set to be lower than the rotation speed of the cutter during the manufacturing process, the generation of cavitation can be suppressed compared with the case where the rotation speed of the cutter is set to be the same as or higher than the rotation speed of the cutter during the manufacturing process.

[0033] A resin pellet manufacturing device according to another embodiment of the present invention comprises: a water tank storing pellet cooling water; a water chamber receiving the pellet cooling water from the water tank; an outgoing path connecting the water tank and the water chamber; a return path connecting the water chamber and the water tank via the upper side of the water chamber; a water supply unit supplying the pellet cooling water from the water tank to the water chamber via the outgoing path; a mold plate having a plurality of mold holes facing the water chamber; and a cutter arranged in the water chamber for manufacturing resin pellets by cutting molten resin ejected from the plurality of mold holes of the mold plate in the water chamber; the water supply unit stops supplying the pellet cooling water before starting the manufacture of the resin pellets if the water level of the pellet cooling water reaches a target water level set at a position lower than the upper end of the return path.

[0034] According to this configuration, since the pump stops ejecting the particle cooling water according to the target water level, the amount of waste particle cooling water can be reduced compared to a case where the particle cooling water is circulated in the circulation flow path and then discharged to set the water level of the particle cooling water to the target water level.

[0035] In the above-mentioned structure, it is also possible to further include: a first auxiliary flow path, having an inner diameter smaller than the inner diameter of the aforementioned forward flow path, for supplying the aforementioned particle cooling water flowing out of the aforementioned water tank to the aforementioned water chamber; a return flow path, branching from the aforementioned forward flow path and connecting the aforementioned forward flow path with the aforementioned water tank; and a flow path switching mechanism, for switching the delivery destination of the aforementioned particle cooling water; the aforementioned first auxiliary flow path starts from an area between the aforementioned water tank and the aforementioned flow path switching mechanism in the aforementioned forward flow path or a specified area in the aforementioned return flow path, and ends at an area between the aforementioned flow path switching mechanism in the aforementioned forward flow path and the aforementioned water chamber or the aforementioned water chamber, and is opened when the aforementioned particle cooling water is supplied to the aforementioned water chamber before the start of the manufacture of the aforementioned resin particles.

[0036] According to this structure, water can be supplied to the water chamber via the first auxiliary flow path having an inner diameter smaller than the inner diameter of the outgoing path. As a result, the flow rate of the particle cooling water flowing into the water chamber can be reduced compared to the case where water is supplied exclusively via the outgoing path. Therefore, the speed at which the particle cooling water accumulates in the water chamber becomes relatively slow, so it becomes easy to stop the water supply when the water surface of the particle cooling water corresponds to the target water level. As a result, the amount of waste particle cooling water can be reduced.

[0037] In the above structure, there may also be a second auxiliary flow path, which has an inner diameter smaller than the inner diameter of the aforementioned outward flow path and is different from the aforementioned first auxiliary flow path; the aforementioned second auxiliary flow path starts from the area between the aforementioned water tank and the aforementioned flow path switching mechanism in the aforementioned outward flow path or the specified area in the aforementioned return flow path, ends at the front end of the rotating shaft of the aforementioned cutter, and is connected to the aforementioned water chamber.

[0038] The resin pellets cut and produced by the cutter are usually transported to the outside of the water chamber by pellet cooling water. However, the resin pellets may be affected by the water flow generated in the water chamber due to the rotation of the cutter and may be retained near the front end of the rotating shaft of the cutter. In contrast, according to this structure, since the front end of the rotating shaft of the cutter is set as the end point of the second auxiliary flow path, the pellet cooling water can be sprayed from the front end to move the resin pellets retained around the front end. As a result, the retained resin pellets can be transported as usual.

[0039] In the above-mentioned structure, a discharge flow passage for discharging the particle cooling water from the water chamber to the outside of the water chamber may be further provided.

[0040] Effects of the Invention

[0041] According to this configuration, the amount of waste pellet cooling water can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a diagram showing a schematic structure of a particle production apparatus according to one embodiment of the present invention.

[0043] Figure 2 yes Figure 1 An enlarged cross-sectional view of a mold plate included in a particle production device.

[0044] Figure 3 This is a flowchart showing a method for producing resin pellets according to one embodiment of the present invention.

[0045] Figure 4 It means use Figure 1 FIG. 1 is a diagram showing the flow of cooling water for pellets when the water storage passage provided in the pellet production device is supplied with water.

[0046] Figure 5 It means use Figure 1 A particle manufacturing device has a diagram of the flow of particle cooling water when the axis passes through the flow path for supplying water.

[0047] Figure 6 It is a diagram showing a schematic structure of a flow path switching mechanism according to a first modified embodiment of the present invention.

[0048] Figure 7 It is a diagram showing a schematic structure of a particle production device according to a second modified embodiment of the present invention.

[0049] Figure 8 Yes means Figure 7 Schematic diagrams of the structure of a flow path switching mechanism of a particle manufacturing device, (a) shows the flow path switching mechanism in a first state, (b) shows the flow path switching mechanism in a second state, and (c) shows the flow path switching mechanism in a third state. DETAILED DESCRIPTION

[0050] <Structure of Particle Manufacturing Apparatus>

[0051] Below, while referring to the attached Figure 1 A pellet production apparatus 1 (resin pellet production apparatus) according to one embodiment of the present invention will be described. Figure 1 This is a diagram showing a schematic configuration of a particle production apparatus 1 according to one embodiment of the present invention. Figure 2 It is an enlarged cross-sectional view of the mold plate 20 described later. In addition, below, the +Y direction in each figure is called an upward direction, and the -Y direction is called a downward direction.

[0052] The particle manufacturing device 1 manufactures resin particles. Figure 1 As shown, the pellet manufacturing device 1 includes a feeder 2, a mixer 4, a gear pump 6, a screen changer 8, a mold holder 10, a mold plate 20, a water chamber 30, a granulator 40, a water tank 50, a pump 60, a cooling device 70, a flow path switching mechanism 80, a dryer 90, an outgoing path 100, a return path 110, a water storage path 120 (a first auxiliary path), an axis passing path 130 (a second auxiliary path), a discharge path 140, and a return path 200.

[0053] The feeder 2 supplies a resin material such as polypropylene or polyethylene to the mixer 4 .

[0054] The mixer 4 is driven by a motor (not shown) to mix the resin material supplied from the feeder 2. The mixer 4 supplies the mixed resin material to a reversing valve (not shown). The reversing valve switches the delivery destination of the resin mixed by the mixer 4. In detail, the reversing valve switches whether to set the delivery destination of the resin to the gear pump 6 or to set the delivery destination of the resin to the outside of the pellet manufacturing device 1.

[0055] The gear pump 6 applies pressure to the resin material supplied from the switching valve, and delivers the resin material toward the die plate 20. The resin pressurized by the gear pump 6 passes through the screen changer 8 and the die holder 10 and reaches the die plate 20.

[0056] The screen changer 8 removes foreign matter contained in the resin supplied from the gear pump 6. The resin having passed through the screen changer 8 passes through the mold holder 10 and moves toward the mold plate 20.

[0057] The mold holder 10 holds the mold plate 20. Inside the mold holder 10, a mold holder passage (not shown) is formed through which the resin material that has passed through the screen changer 8 flows.

[0058] The mold plate 20 is held by the mold holder 10 and arranged to face the water chamber 30. The mold plate 20 has a plurality of mold holes 20H ( Figure 2 ), heating medium flow path 21 ( Figure 2 ) and temperature transmitter 22 ( Figure 1 ). The plurality of mold holes 20H connect the aforementioned mold retainer passage with the interior of the water chamber 30, and guide the resin material after passing through the aforementioned mold retainer passage to the interior of the water chamber 30. That is, the resin material that has passed through the mold retainer passage and reached the plurality of mold holes 20H is ejected into the water chamber 30 via the plurality of mold holes 20H. Each mold hole 20H is formed into a small diameter, and thus, the resin material ejected from each mold hole 20H is formed into a slender shape. The heat medium flow path 21 is a flow path for the heat medium that heats the mold plate 20 to flow. As the heat medium, for example, steam, hot oil, etc. are used. The temperature transmitter 22 measures the temperature of the mold plate 20. The temperature measured by the temperature transmitter 22 is transmitted to a control device, etc., not shown in the figure.

[0059] Back to Figure 1 The water chamber 30 is a container that receives pellet cooling water PCW (pellet cooling water) from the water tank 50 and stores the pellet cooling water PCW. The pellet cooling water PCW is a liquid that cools the resin pellets produced in the pellet production device 1 while conveying the resin pellets.

[0060] The pelletizer 40 cuts the resin material ejected from the die plate 20 to produce resin pellets. Specifically, the pelletizer 40 includes a pelletizer motor 42 , a rotary shaft 44 , a cutter holder 46 , and a plurality of cutters 48 .

[0061] The granulator motor 42 is a driving source for rotating the plurality of cutters 48 .

[0062] The rotating shaft 44 has one end connected to the pelletizer motor 42 and the other end 47 (front end) which is arranged in the water chamber 30 and on which the cutter holder 46 is mounted. The rotating shaft 44 transmits the rotational force generated by the pelletizer motor 42 to the cutter holder 46. The rotating shaft 44 is formed in a cylindrical shape, and the radial inner space of the rotating shaft 44 is connected to the inside of the water chamber 30. In addition, the rotating shaft 44 is connected to a hydraulic unit or an air pressure unit (not shown) and can move forward and backward in the axial direction. That is, the rotating shaft 44 can make the cutter holder 46 approach and move away from the mold plate 20.

[0063] The cutter holder 46 is mounted on the rotating shaft 44 so as to surround the other end 47 of the rotating shaft 44 in the circumferential direction. A plurality of cutters 48 are fixed to the cutter holder 46. Specifically, a plurality of cutters 48 are arranged at equal or unequal intervals along the circumferential direction on the radial end surface of the cutter holder 46.

[0064] The plurality of cutters 48 extend in the radial direction starting from the radial end surface of the cutter holder 46. When the rotating shaft 44 is advanced in the axial direction, the plurality of cutters 48 come into contact with the surface of the die plate 20. The pelletizer motor 42 is driven to rotate the cutter holder 46, and the plurality of cutters 48 rotate in the circumferential direction of the cutter holder 46 with the rotating shaft 44 as the rotation center.

[0065] The water tank 50 is a container storing the pellet cooling and transporting water PCW. The water tank 50 includes a heating device 52. The heating device 52 heats the pellet cooling and transporting water PCW stored in the water tank 50.

[0066] The pump 60 discharges the particle cooling water PCW stored in the water tank 50 toward the water chamber 30. The pump 60 according to the present embodiment does not have a function of adjusting the flow rate of the particle cooling water PCW, but the pump 60 may have this function in other embodiments.

[0067] The cooling device 70 is disposed on the downstream side of the pump 60 , and cools the particle cooling transport water PCW flowing from the water tank 50 toward the water chamber 30 .

[0068] The flow path switching mechanism 80 is arranged on the downstream side of the pump 60 in the outgoing path 100, and is a three-way valve having a first port connected to the outgoing path first portion 100a described later, a second port connected to the outgoing path second portion 100b described later, and a third port connected to the return flow path 110. The flow path switching mechanism 80 related to the present embodiment can switch the state between the first state and the second state. The first state is a state in which the outgoing path first portion 100a is connected to the outgoing path second portion 100b and the outgoing path first portion 100a is blocked from being connected to the return flow path 110. In other words, the first state can be a state in which the particle cooling transport water PCW flowing out of the water tank 50 is transported to the water chamber 30 by means of the water flow generated by the pump 60. The second state is a state in which the outgoing path first portion 100a is connected to the return flow path 110 and the outgoing path first portion 100a is blocked from being connected to the outgoing path second portion 100b. In other words, the second state can be a state in which the particle cooling transport water PCW flowing out of the water tank 50 is transported exclusively to the water tank 50 .

[0069] The dryer 90 is disposed above the water chamber 30 and dries the resin pellets. The dryer 90 includes a separation device (not shown) for separating the resin pellets from foreign matter.

[0070] The outgoing passage 100 constitutes a part of the circulation flow path 300, and connects the water tank 50 to the lower part of the water chamber 30. The inner diameter of the outgoing passage 100 is set to about 12 inches to 14 inches. The outgoing passage 100 includes: an outgoing passage first portion 100a, which is arranged between the water tank 50 and the flow path switching mechanism 80; and an outgoing passage second portion 100b, which is arranged between the flow path switching mechanism 80 and the water chamber 30. Figure 1 As shown, a water level gauge 102 for measuring the water level of the pellet cooling transport water PCW is provided in the outward second portion 100b.

[0071] The return flow path 110 branches off from the outward flow path 100 and connects the outward flow path 100 and the tank 50 .

[0072] The water storage passage 120 is arranged in parallel with at least a portion of the outgoing passage 100. The water storage passage 120 has an inner diameter smaller than the inner diameter of the outgoing passage 100. Specifically, the inner diameter of the water storage passage 120 is set to about 2 inches to 3 inches. Figure 1As shown, the water storage flow path 120 of the present embodiment has a predetermined area in the outgoing path first part 100a as a starting point and a predetermined area in the outgoing path second part 100b as an end point. That is, the water storage flow path 120 has a structure that branches from the outgoing path first part 100a and reaches the outgoing path second part 100b. A water storage flow path valve 122 is provided in the water storage flow path 120. The water storage flow path valve 122 is an on-off valve that can switch between an open state in which the water storage flow path 120 is opened and a closed state in which the water storage flow path 120 is closed. In the present embodiment, the water storage flow path valve 122 functions as a water supply unit that supplies the particle cooling transport water PCW from the water tank 50 to the water chamber 30 via the outgoing path 100.

[0073] The shaft passage flow path 130 is arranged in parallel with at least a part of the outgoing passage 100. The shaft passage flow path 130 has an inner diameter smaller than the inner diameter of the outgoing passage 100. Specifically, the inner diameter of the shaft passage flow path 130 is set to be about 2 inches to 3 inches. The shaft passage flow path 130 related to the present embodiment starts from a predetermined area in the first part 100a of the outgoing passage, passes through the inside of the rotating shaft 44, and ends at the other end 47 of the rotating shaft 44, and is connected to the water chamber 30. A shaft passage flow path valve 132 is provided in the shaft passage flow path 130. The shaft passage flow path valve 132 is an on-off valve that switches between an open state in which the shaft passage flow path 130 is opened and a closed state in which the shaft passage flow path 130 is closed.

[0074] The discharge flow path 140 connects the bottom of the water chamber 30 to a discharge tank (not shown) provided in the particle production apparatus 1. A discharge flow path valve 142 whose opening can be adjusted is provided in the discharge flow path 140. When the discharge flow path valve 142 is opened, the particle cooling transport water PCW stored in the water chamber 30 flows to the discharge tank.

[0075] The return path 200 extends through the upper part of the water chamber 30 to connect the water chamber 30 and the water tank 50. Specifically, the return path 200 includes an upper connecting flow path 150, an ascending inclined flow path 160 (inclined flow path), a dryer connecting flow path 170, and a water tank connecting flow path 180.

[0076] The upper connecting flow path 150 is connected to the upper end of the water chamber 30 and extends upward from the upper end as a starting point.

[0077] The ascending inclined flow path 160 is inclined in a manner that the front end rises toward the dryer 90. The ascending inclined flow path 160 has a base end 162 (lower end) connected to the upper connecting flow path 150 and an upper end 163 (upper end) connected to the dryer connecting flow path 170. Figure 1 As shown, the upper end portion 163 is located at the uppermost side (the highest position) in the return path 200. Specifically, the upper end portion 163 is located about 20 m above the upper end of the water chamber 30.

[0078] The dryer connecting flow path 170 connects the upper end portion 163 of the ascending inclined flow path 160 to the dryer 90 .

[0079] The water tank connection flow path 180 extends downward from the dryer 90 to connect the dryer 90 and the water tank 50 .

[0080] The water chamber 30, the water tank 50, the outgoing passage 100 and the return passage 200 constitute the circulation flow passage 300. In the circulation flow passage 300, the particle cooling transport water PCW ejected from the water tank 50 by the pump 60 reaches the water chamber 30 via the outgoing passage 100, and the particle cooling transport water PCW flowing out of the water chamber 30 reaches the water tank 50 via the return passage 200 (the upper connecting passage 150, the ascending inclined passage 160, the dryer connecting passage 170 and the water tank connecting passage 180) from above the water chamber 30.

[0081] <Method for producing resin pellets in resin pellet producing apparatus>

[0082] Next, a method for producing resin pellets in the pellet production apparatus 1 according to the present embodiment will be described. Figure 3 This is a flow chart showing a method for producing resin pellets. Figure 4 1 is a diagram showing the flow of particle cooling water when water is supplied to the water chamber 30 using the water storage flow path 120 . Figure 5 The figure shows the flow of particle cooling water PCW when water is supplied to the water chamber 30 through the shaft passage 130. In the following, it is assumed that the inside of the die hole 20H of the die plate 20 is clogged with solidified resin after the previous manufacturing process (described later).

[0083] Reference Figure 3 First, a water supply process is performed to supply the particle cooling water PCW stored in the water tank 50 to the empty water chamber 30 (step S1). In the water supply process, the particle cooling water PCW is transported to the water chamber 30 by using the water storage flow path 120. In detail, the flow path switching mechanism 80 is switched to the second state (the state in which the first part 100a of the outgoing path is connected to the return flow path 110) and the water storage flow path valve 122 is switched to the open state, so that the water storage flow path 120 is opened. If the pump 60 is started in this state, as shown in FIG. Figure 4 As shown, part of the particle cooling and transporting water PCW ejected from the water tank 50 by the pump 60 flows to the water tank 50 via the return flow path 110 , and the remaining particle cooling and transporting water PCW flows to the water chamber 30 via the water storage flow path 120 .

[0084] In the water supply process, the water chamber 30 is filled with the particle cooling water PCW supplied to the water chamber 30 via the water storage flow path 120. Then, referring to the measurement value of the water level meter 102, when the water level (water surface) of the particle cooling water PCW reaches a water level lower than the upper end 163 of the ascending inclined flow path 160, that is, the target water level TL ( Figure 1 ), the water storage flow path valve 122 is switched to a closed state to stop the supply of particle cooling conveying water PCW.

[0085] The target water level TL is a water level lower than the water level of the particle cooling water PCW when the circulation is stopped after the particle cooling water PCW is circulated. It is preferable to set the target water level TL to a position (height) that suppresses excessive water pressure acting on the water chamber 30. In detail, it is preferable to set the target water level TL to a position (height) that can suppress the generation of the following water pressure, wherein the resin material existing in the plurality of mold holes 20H of the mold plate 20 is pushed back and the particle cooling water PCW intrudes into the plurality of mold holes 20H. Figure 1 As shown, the target water level TL according to the present embodiment is set at a position higher than the upper portion of the water chamber 30 and lower than the base end portion 162 of the ascending inclined flow path 160. That is, the target water level TL is set at an arbitrary region in the upper connecting flow path 150.

[0086] Next, a rotation process is performed in which the cutters 48 are rotated while being in contact with the mold plate 20 (step S2). First, in the rotation process, the pellet cooling water PCW is supplied to the water chamber 30 via the shaft passage 130. Specifically, the passage switching mechanism 80 is set to the second state (the state in which the first portion 100a of the outgoing passage is connected to the return passage 110) and the shaft passage passage valve 132 is opened to open the shaft passage passage 130. If this is done, as shown in FIG. Figure 5 As shown, a portion of the particle cooling and transporting water PCW flowing out of the water tank 50 flows to the water tank 50 via the return flow path 110 , and the remaining particle cooling and transporting water PCW flows to the water chamber 30 via the shaft passing flow path 130 .

[0087] In the rotation process according to the present embodiment, while the particle cooling transport water PCW is supplied to the water chamber 30, a part of the particle cooling transport water PCW is discharged through the discharge flow path 140. Specifically, the particle cooling transport water PCW is discharged in a state where the flow rate of the particle cooling transport water PCW discharged from the water chamber 30 is adjusted by adjusting the opening of the discharge flow path valve 142. Thus, the position of the water surface of the particle cooling transport water PCW can be maintained at the target water level TL.

[0088] Then, while the pellet cooling water PCW is being supplied and discharged, the rotating shaft 44 is advanced in the axial direction to bring the plurality of cutters 48 into contact with the die plate 20, and the pelletizer motor 42 is started to rotate the plurality of cutters 48. In addition, the rotation of the plurality of cutters 48 may be started at a time point earlier than the rotation process, for example, at the time point of the water supply process.

[0089] In the rotating step according to the present embodiment, the output of the granulator motor 42 is adjusted so that the rotation speed of the plurality of cutters 48 becomes lower than the rotation speed of the plurality of cutters 48 in the manufacturing step described later.

[0090] Next, the heating medium is made to flow to the heating medium flow path 21 ( Figure 2 ) to heat the mold plate 20 (step S3). In the heating process related to the present embodiment, the particle cooling and transporting water PCW is supplied through the water storage flow path 120 or the shaft passing flow path 130, and the particle cooling and transporting water PCW is discharged through the discharge flow path 140. At this time, the rotation of the plurality of cutters 48 continues.

[0091] Next, a waiting process is performed until the mold plate 20 reaches a predetermined temperature (a temperature at which the resin material plugging the mold hole 20H melts) (step S4). As described above, the temperature of the mold plate 20 is measured by the temperature transmitter 22, so whether the predetermined temperature has been reached is determined based on the measured value of the temperature transmitter 22.

[0092] Next, once the mold plate 20 reaches a predetermined temperature, a circulation process is performed to circulate the particle cooling water PCW (step S5). In the circulation process, the flow path switching mechanism 80 is switched to the first state (the state in which the first outgoing path portion 100a is connected to the second outgoing path portion 100b), so that the particle cooling water PCW circulates in the circulation flow path 300.

[0093] Next, a start-up process (step S6) is performed to start the mixer 4, the feeder 2, and the gear pump 6. In the start-up process, the resin material newly supplied from the feeder 2, mixed by the mixer 4, and pressed by the gear pump 6 to reach the plurality of die holes 20H pushes the molten resin in the plurality of die holes 20H toward the inside of the water chamber 30. In other words, the start-up process is a process (material supply process) of supplying the resin material from the upstream (upstream in the conveying direction of the resin material) to the die plate 20.

[0094] Each process from step S1 to step S6 described above corresponds to a method of starting up the particle production apparatus 1 .

[0095] Next, a manufacturing process for manufacturing resin pellets is performed (step S7). First, in the manufacturing process, the molten resin ejected to the inner side of the water chamber 30 is cut by a plurality of cutters 48 to manufacture resin pellets. At this time, the pellet cooling and conveying water PCW is supplied from the shaft through the flow path 130, so that the resin pellets will not be retained near the rotation center of the cutter 48 (near the other end 47) due to the water flow generated in the water chamber 30 by the rotation of the plurality of cutters 48. Next, while the resin pellets are cooled by the pellet cooling and conveying water PCW stored in the water chamber 30, the resin pellets are conveyed to the dryer 90 by the pellet cooling and conveying water PCW flowing out of the water chamber 30. Then, after the resin pellets are dried by the dryer 90, the dried resin pellets are ejected to the outside of the pellet manufacturing device 1. Thus, resin pellets are manufactured.

[0096] In addition, the resin pellets produced after the start of the manufacturing process may not meet the quality of the product, so these resin pellets can also be discarded. In this case, it can also be considered that the startup method of the pellet manufacturing device 1 is equivalent to discarding the resin pellets.

[0097] Next, once a predetermined number of resin pellets have been manufactured in the manufacturing process, a shutdown process (step S8) is performed to stop the operation of the pellet manufacturing device 1. In the shutdown process, the operation of the mixer 4, the feeder 2, and the gear pump 6 is stopped to stop the supply of the resin material, and the heating of the mold plate 20 is stopped in a state where the molten resin exists inside the plurality of mold holes 20H. Then, the pellet cooling and conveying water PCW is circulated in the circulation flow path 300 until the resin material blocked in the mold hole 20H reaches a predetermined temperature (a temperature at which the molten material blocked in the mold hole 20H solidifies). As a result, the resin material blocked in the mold hole 20H exchanges heat with the circulating pellet cooling and conveying water PCW and solidifies inside the mold hole 20H. If this is done, the next operation of the pellet manufacturing device 1 can be restarted from the above-mentioned "state in which the solidified resin is blocked inside the mold hole 20H of the mold plate 20". That is, the next operation can be restarted from the state of step S1. Then, the operation of the pellet manufacturing device 1 is stopped.

[0098] As described above, in the water supply process according to the present embodiment, the supply of the particle cooling transport water PCW is stopped in accordance with the target water level TL. Therefore, compared with the case where the particle cooling transport water PCW is circulated in the circulation flow path 300 and then discharged to set the water level of the particle cooling transport water PCW to the target water level TL, the amount of waste particle cooling transport water PCW can be reduced.

[0099] Furthermore, in the water supply process related to the above-mentioned embodiment, a part of the particle cooling transport water PCW returns to the water tank 50, and the remaining particle cooling transport water PCW is supplied to the water chamber 30. As a result, the flow rate of the particle cooling transport water PCW flowing into the water chamber 30 can be reduced compared to the case where a part of the particle cooling transport water PCW is not returned to the water tank 50. As a result, the speed at which the particle cooling transport water PCW is accumulated in the water chamber 30 becomes relatively slow, so it becomes easy to stop the water supply when the water surface of the particle cooling transport water PCW corresponds to the target water level TL.

[0100] In addition, in the water supply process related to the above-mentioned embodiment, since the particle cooling transport water PCW is supplied to the water chamber 30 via the water storage flow path 120 having an inner diameter smaller than the inner diameter of the outgoing path 100, it is easy to stop the water supply when it corresponds to the target water level TL. In detail, as described above, the inner diameter of the outgoing path 100 (the second part 100b of the outgoing path) is set to about 12 inches to 14 inches, so when the outgoing path second part 100b is used exclusively for water supply, the particle cooling transport water PCW is quickly accumulated in the water chamber 30. Therefore, in this case, it is difficult to stop the water supply at the target water level TL. On the other hand, if the particle cooling transport water PCW is supplied via the water storage flow path 120 having an inner diameter smaller than the inner diameter of the outgoing path 100 as in the present embodiment, the flow rate of the particle cooling transport water PCW flowing into the water chamber 30 can be reduced compared with the case where the water is supplied exclusively via the second part 100b of the outgoing path. As a result, the speed at which the particle cooling transport water PCW is accumulated in the water chamber 30 becomes relatively slow, so that it becomes easy to stop the water supply when the water surface of the particle cooling transport water PCW reaches the target water level TL in the water supply process.

[0101] In addition, in order to reduce the flow rate of the particle cooling water PCW flowing into the water chamber 30, it is also conceivable to provide the particle manufacturing device 1 with a pump having a flow rate adjustment function instead of the pump 60 related to the present embodiment. However, a pump having such a function is generally expensive, so such a measure may increase the manufacturing cost of the particle manufacturing device 1. In contrast, in the present embodiment, since the flow rate of the particle cooling water PCW can be reduced without using the above-mentioned expensive pump, the increase in manufacturing cost can be suppressed.

[0102] Furthermore, in the rotation process according to the above-described embodiment, the particle cooling water PCW is supplied through the shaft through the flow path 130, so that the temperature of the mold plate 20 can be controlled. Specifically, in the rotation process, the temperature of the mold plate 20 may be excessively increased due to frictional heat generated by the rotation of the plurality of cutters 48 in contact with the mold plate 20. In contrast, according to the above-described configuration, the temperature of the mold plate 20 can be controlled by the particle cooling water PCW supplied from the shaft through the flow path 130. That is, the temperature of the mold plate 20 can be suppressed from excessively increasing.

[0103] In particular, in the rotation process according to the above-described embodiment, the particle cooling water PCW is supplied not through the water storage passage 120 but through the shaft passage passage 130. That is, the particle cooling water PCW can be supplied through the shaft passage passage 130 ending at the other end 47 located near the mold plate 20. Thus, the particle cooling water PCW can be supplied near the mold plate 20, so that the temperature of the mold plate 20 can be more reliably suppressed from excessively rising.

[0104] Furthermore, in the rotating step of the above-described embodiment, the pellet cooling transport water PCW is supplied and discharged while the plurality of cutters 48 are rotated. That is, the pellet cooling transport water PCW in the water chamber 30 can be replaced while the plurality of cutters 48 rotating in the water chamber 30 can be used to stir the pellet cooling transport water PCW in the water chamber 30. This can suppress the occurrence of local boiling in the water chamber 30. As a result, the temperature of the surface of the mold plate 20 facing the water chamber 30 can be uniformly maintained.

[0105] Furthermore, according to the above configuration, the resin dripping from the die holes 20H of the die plate 20 and picked up by the plurality of cutters 48 can be discharged to the outside of the water chamber 30 together with the pellet cooling transport water PCW discharged from the water chamber 30 .

[0106] In the rotation process according to the above embodiment, the flow rate of the particle cooling water PCW discharged from the discharge flow path 140 is adjusted so that the water surface of the particle cooling water PCW is maintained at the target water level TL. Therefore, it is possible to prevent the water surface of the particle cooling water PCW from being at a level deviating from the target water level TL.

[0107] Furthermore, in the water supply process according to the above-described embodiment, since the target water level TL is set at a position lower than the base end 162 of the ascending inclined flow path 160, the water pressure acting in the water chamber 30 can be suppressed compared to the case where the target water level TL is set at a position higher than the base end 162. Thus, it is possible to efficiently suppress the resin material existing inside the plurality of mold holes 20H of the mold plate 20 from being pushed back and the pellet cooling feed water PCW from intruding into the mold holes 20H.

[0108] Furthermore, in the water supply process of the above-mentioned embodiment, since it is not necessary to discharge the particle cooling transport water PCW in the ascending inclined flow path 160, the amount of waste particle cooling transport water PCW can be reduced. Specifically, when the particle cooling transport water PCW is supplied to the upper end portion 163 of the ascending inclined flow path 160 by circulating the particle cooling transport water PCW, and then the particle cooling transport water PCW is discharged to set the water level of the particle cooling transport water PCW to the target water level TL, the particle cooling transport water PCW accumulated in the ascending inclined flow path 160 is discharged. Figure 1 The particle cooling transport water PCW in the flooded area AR shown in the figure is discharged. In contrast, in the water supply process according to the present embodiment, after the water chamber 30 is filled with the particle cooling transport water PCW, the supply of the particle cooling transport water PCW is stopped at the point in time when the water level of the particle cooling transport water PCW corresponds to the target water level TL. In this way, water does not accumulate in the flooded area AR, so it is no longer necessary to discharge the particle cooling transport water PCW. As a result, the amount of waste particle cooling transport water PCW is reduced.

[0109] In the rotation process of the above-mentioned embodiment, since the output of the pelletizer motor 42 is adjusted so that the rotation speed of the plurality of cutters 48 is lower than the rotation speed of the plurality of cutters 48 in the manufacturing process, the generation of cavitation in the water chamber 30 is suppressed. As described above, in the stage of the rotation process, the water level of the pellet cooling and conveying water PCW is maintained at the target water level TL, and the water pressure acting on the water chamber 30 is suppressed. Therefore, if the rotation speed of the plurality of cutters 48 in the rotation process is set to be the same as or higher than the rotation speed of the plurality of cutters 48 in the manufacturing process, there is a possibility that cavitation will occur. In contrast, in the present embodiment, since the output of the pelletizer motor 42 is adjusted so that the rotation speed of the plurality of cutters 48 in the rotation process is lower than the rotation speed of the plurality of cutters 48 in the manufacturing process, the generation of cavitation can be suppressed.

[0110] In addition, in the particle manufacturing device 1 related to the above-mentioned embodiment, since the pump 60 stops the discharge of the particle cooling transport water PCW corresponding to the target water level TL, the amount of waste of the particle cooling transport water PCW can be reduced compared to the case where the particle cooling transport water PCW is discharged after circulating the particle cooling transport water PCW in the circulation flow path 300 and the water surface of the particle cooling transport water PCW is set to the target water level TL.

[0111] Furthermore, in the particle production device 1 according to the above-described embodiment, water can be supplied to the water chamber 30 via the water storage flow path 120 having an inner diameter smaller than the inner diameter of the outgoing path 100. Thus, the flow rate of the particle cooling transport water PCW flowing into the water chamber 30 can be reduced compared to the case where water is supplied exclusively via the outgoing path 100. Therefore, since the speed at which the particle cooling transport water PCW is accumulated in the water chamber 30 becomes relatively slow, it becomes easy to stop the water supply when the water surface of the particle cooling water corresponds to the target water level TL. As a result, the amount of waste of the particle cooling transport water PCW can be reduced.

[0112] In the pellet production device 1 according to the above-mentioned embodiment, since the end point of the shaft-passing flow path 130 is set at the other end 47, that is, the front end of the rotating shaft 44, the resin pellets accumulated near the other end 47 can be conveyed as usual. Specifically, the resin pellets produced by cutting by the plurality of cutters 48 are usually conveyed to the outside of the water chamber 30 by the pellet cooling conveying water PCW. However, the resin pellets may be affected by the water flow generated in the water chamber 30 by the rotation of the plurality of cutters 48 and accumulate near the other end 47. In contrast, according to the present configuration, since the end point of the shaft-passing flow path 130 is set at the other end 47, the pellet cooling water can be ejected from the other end 47 to move the resin pellets accumulated around the other end 47. As a result, the resin pellets accumulated near the other end 47 can be conveyed as usual.

[0113] Furthermore, since the particle production apparatus 1 according to the above-described embodiment includes the discharge flow path 140 , the particle cooling and transporting water PCW can be discharged.

[0114] Furthermore, in the heating process according to the present embodiment, the particle cooling transport water PCW is supplied via the water storage flow path 120 or the shaft passing flow path 130, and the particle cooling transport water PCW is discharged via the discharge flow path 140. That is, the particle cooling transport water PCW in the water chamber 30 is appropriately replaced. According to this structure, it is possible to suppress the water temperature of the particle cooling transport water PCW in the water chamber 30 from excessively rising.

[0115] Furthermore, in the heating process according to the present embodiment, the plurality of cutters 48 rotate. According to this structure, the particle cooling conveying water PCW stored in the water chamber 30 is stirred by the rotation of the plurality of cutters 48, and the water temperature in the water chamber 30 is made uniform. Therefore, the mold plate 20 can be heated uniformly.

[0116] Furthermore, in the startup method of the particle manufacturing apparatus 1 according to the above-mentioned embodiment, unlike the case where the particle cooling transport water PCW is circulated in the circulation flow path 300 and then discharged to set the water level of the particle cooling transport water PCW to the target water level TL, it is not necessary to discharge the particle cooling transport water PCW. Therefore, the particle manufacturing apparatus 1 can be started up relatively quickly.

[0117] The particle production device 1 according to one embodiment of the present invention has been described above. The present invention is not limited to the above-described embodiment. The present invention may have the following modified embodiments.

[0118] (1) In the above embodiment, an example in which the flow path switching mechanism 80 is composed of a three-way valve has been described. However, the flow path switching mechanism may be composed of two opening and closing valves instead. Figure 6 1 is a diagram showing a schematic structure of a flow path switching mechanism 80A according to the present modified embodiment. Figure 6 As shown, the flow path switching mechanism 80A related to this modified embodiment has a first opening and closing valve 81A and a second opening and closing valve 82A. The first opening and closing valve 81A is an opening and closing valve that switches between an open state in which the first part 100a of the outgoing path is connected to the second part 100b of the outgoing path and a closed state in which the two parts 100a and 100b are cut off. The second opening and closing valve 82A is an opening and closing valve that switches between an open state in which the return flow path 110 is opened and a closed state in which the return flow path 110 is closed. For example, by setting the first opening and closing valve 81A to an open state and the second opening and closing valve 82A to a closed state, the same water flow as the first state of the flow path switching mechanism 80 related to the previous embodiment can be achieved. In addition, by setting the first opening and closing valve 81A to a closed state and the second opening and closing valve 82A to an open state, the same water flow as the second state of the flow path switching mechanism 80 related to the previous embodiment can be achieved. Furthermore, by opening the first on-off valve 81A and opening the second on-off valve 82A, both the water chamber 30 and the water tank 50 can be used as the transport destination of the particle cooling transport water PCW.

[0119] (2) In the above embodiment, the particle production apparatus 1 is described as including the water storage passage 120 , but the water storage passage 120 is not essential.

[0120] Figure 7 It is a development view of a particle production apparatus 1B according to this modified embodiment. Figure 8 It is a schematic diagram showing the structure of a flow path switching mechanism 80B according to a modified embodiment. Figure 8 (a) shows the flow path switching mechanism 80B in the first state, Figure 8 (b) shows the flow path switching mechanism 80B in the second state. Figure 8(c) shows the flow path switching mechanism 80B in the third state. In addition, in this modified embodiment, the differences from the above-mentioned embodiment will be mainly described, and the description of the common points will be omitted.

[0121] like Figure 7 As shown, the particle production apparatus 1B is different from the particle production apparatus 1 according to the previous embodiment in that it does not include the water storage flow path 120. In addition, the particle production apparatus 1B includes a flow path switching mechanism 80B instead of the flow path switching mechanism 80 according to the previous embodiment.

[0122] The flow path switching mechanism 80B is arranged on the downstream side of the pump 60 in the outgoing flow path 100 and is a three-way valve having a first port connected to the outgoing flow path first portion 100a, a second port connected to the outgoing flow path second portion 100b, and a third port connected to the return flow path 110. Figure 8 As shown in (a) to (c) of FIG. 1 , the flow path switching mechanism 80B can switch the state between the first state, the second state and the third state. Figure 8 (a)) is a state where the first outgoing portion 100a is connected to the second outgoing portion 100b and the return flow path 110. The first state can be said to be a state where both the water chamber 30 and the water tank 50 are used as the delivery destination of the particle cooling delivery water PCW. Figure 8 (b)) is a state in which the first outgoing path portion 100a is connected to the second outgoing path portion 100b while the first outgoing path portion 100a is blocked from being connected to the return flow path 110. The second state can be said to be a state in which the water chamber 30 is set as the delivery destination of the particle cooling delivery water PCW. Figure 8 (c)) is a state in which the first outgoing passage portion 100a is connected to the return flow path 110 while the first outgoing passage portion 100a is blocked from being connected to the second outgoing passage portion 100b. In other words, the third state is a state in which the water tank 50 is exclusively used as the delivery destination of the particle cooling delivery water PCW.

[0123] In the water supply process of the particle production apparatus 1B, the particle cooling and transporting water PCW is supplied to the water chamber 30 by closing the shaft-passing flow path valve 132 while the flow path switching mechanism 80B is set to the first state.

[0124] In the rotation process of the particle manufacturing device 1B, the flow path switching mechanism 80B is set to the third state, and the shaft flow path valve 132 is opened to open the shaft flow path 130 , thereby supplying particle cooling transport water PCW to the water chamber 30 through the shaft flow path 130 .

[0125] Furthermore, if Figure 7As shown, a flow regulating valve 105B having an adjustable opening is provided in the outward passage first portion 100a of the pellet manufacturing device 1B. By making the opening of the flow regulating valve 105B smaller, the flow rate of the pellet cooling water PCW flowing into the water chamber 30 can be reduced.

[0126] As described above, in the water supply process of the particle production device 1B according to the present modified embodiment, since the flow path switching mechanism 80B is set to the first state (the state in which the outgoing path first portion 100a is connected to both the outgoing path second portion 100b and the return flow path 110), a part of the particle cooling transport water PCW is returned to the water tank 50, and the remaining particle cooling transport water PCW is supplied to the water chamber 30. As a result, the flow rate of the particle cooling transport water PCW flowing into the water chamber 30 can be reduced compared to the case where a part of the particle cooling transport water PCW is not returned to the water tank 50. As a result, the speed at which the particle cooling transport water PCW is accumulated in the water chamber 30 becomes relatively slow, so it becomes easy to stop the water supply according to the target water level TL. That is, in the water supply process, the same effect as the case where the particle cooling transport water PCW is supplied to the water chamber 30 using the water storage flow path 120 or the shaft passing flow path 130 related to the previous embodiment can be achieved without using the water storage flow path 120 or the shaft passing flow path 130 related to the previous embodiment.

[0127] In addition, when there is a need to circulate the particle cooling transport water PCW in the circulation process, the flow path switching mechanism 80B can be switched to the second state (the state in which the outgoing path first part 100a is connected to the outgoing path second part 100b) and the transport destination of the particle cooling transport water PCW is set to the water chamber 30.

[0128] In addition, when there is a need to switch the delivery destination of the particle cooling transport water PCW to the water tank 50, for example, when water is supplied via the shaft through the flow path 130, it is sufficient to set the flow path switching mechanism 80B to the third state (the state in which the first part 100a of the outgoing path is connected to the return flow path 110).

[0129] As described above, the particle production apparatus 1B according to the present modified embodiment includes the flow path switching mechanism 80B instead of the flow path switching mechanism 80 according to the previous embodiment, and therefore the transport destination of the particle cooling transport water PCW can be easily switched according to the purpose.

[0130] Furthermore, the particle manufacturing device 1B according to the present modified embodiment is provided with a flow regulating valve 105B which is a valve capable of adjusting the opening degree. Therefore, for example, when the flow path switching mechanism 80B is set to the first state, by setting the opening degree of the flow regulating valve 105B to be smaller, the flow rate of the particle cooling transport water PCW supplied to the water chamber 30 can be further reduced. As a result, the speed at which the particle cooling transport water PCW is accumulated in the water chamber 30 becomes slower, so it becomes easier to stop the water supply when the water surface of the particle cooling water corresponds to the target water level TL.

[0131] (3) In the above embodiment, an example is described in which the particle cooling transport water PCW is supplied to the water chamber 30 via the water storage flow path 120 in the water supply process, but the particle cooling transport water PCW may be supplied via the shaft passage flow path 130 instead. In other words, the shaft passage flow path valve 132 of the shaft passage flow path 130 may also function as the water supply unit related to the present invention. Alternatively, in the water supply process, the particle cooling transport water PCW may be supplied to the water chamber 30 using both the water storage flow path 120 and the shaft passage flow path 130. That is, the water storage flow path valve 122 of the water storage flow path 120 and the shaft passage flow path valve 132 of the shaft passage flow path 130 may also function as the water supply unit related to the present invention.

[0132] (4) In the above embodiment, the water storage flow path 120 is described as starting from the predetermined area in the first portion 100a of the forward path and ending at the predetermined area in the second portion 100b of the forward path, but the starting point and the ending point of the water storage flow path 120 are not limited thereto. Although not shown in the figure, the water storage flow path 120 may also start from the predetermined area in the return flow path 110. Also, although not shown in the figure, the water storage flow path 120 may end at the water chamber 30.

[0133] (5) In the above embodiments, the shaft-passing flow path 130 is described as starting from a predetermined area in the first portion 100a of the conventional flow path and ending at the other end 47 of the rotating shaft 44, but the starting point of the shaft-passing flow path 130 is not limited thereto. Although not shown in the figure, the shaft-passing flow path 130 may also start from any area in the return flow path 110.

[0134] (6) The particle production apparatus 1 according to the above embodiment may further include a water volume adjustment flow path starting from the upper part of the water chamber 30 or a region lower than the target water level TL in the upper connecting flow path 150 and ending at a discharge tank (not shown).

[0135] (7) In the above embodiments, the water storage flow path valve 122 is described as an example of the water supply unit according to the present invention, but the pump 60 may function as the water supply unit instead. In this case, the water supply in the water supply process may be stopped by stopping the operation of the pump 60. In addition, the operation of the pump 60 may be stopped manually, or the operation may be automatically stopped by a control device (not shown) provided in the particle manufacturing apparatus 1.

[0136] Description of Reference Numerals

[0137] 1.1B: Particle manufacturing device

[0138] 20: Mold plate

[0139] 20H: Die hole

[0140] 30: Water Chamber

[0141] 44: Rotation axis

[0142] 47: The other end (the front end of the rotating shaft)

[0143] 48: Cutter

[0144] 50: Water tank

[0145] 60: Pump

[0146] 80, 80A, 80B: Flow path switching mechanism

[0147] 100: the way forward

[0148] 110: Return flow

[0149] 120: Water storage flow path (first auxiliary flow path)

[0150] 122: Water storage flow valve (water supply part)

[0151] 130: Axis passage (second auxiliary passage)

[0152] 140: Discharge flow path

[0153] 150: Upper connection flow path

[0154] 160: Ascending inclined flow path (inclined flow path)

[0155] 162: Base end (lower end)

[0156] 163: Upper end

[0157] 200: Return

[0158] 300: Circulation path

[0159] PCW: Pellet cooling water (pellet cooling water)

[0160] TL: Target water level

Claims

1. A method for starting a resin pellet manufacturing device, the resin pellet manufacturing device comprising: a circulation flow path having an outward path for pellet cooling water ejected from a water tank by a pump to reach a water chamber and a return path for the pellet cooling water to reach the water tank from the water chamber via the upper side of the water chamber; a die plate having a plurality of die holes and arranged facing the water chamber; and a cutter arranged in the water chamber to cut molten resin ejected from the plurality of die holes to manufacture resin pellets; while cooling the manufactured resin pellets with the pellet cooling water flowing in the circulation flow path, the resin pellets are conveyed from the water chamber; the method for starting a resin pellet manufacturing device is characterized in that: The invention comprises: a water supply process, before starting the manufacture of the resin pellets, supplying the pellet cooling water stored in the water tank to the water chamber by the pump to fill the water chamber, and then stopping the supply of the pellet cooling water so that the water level of the pellet cooling water becomes a target water level set at a position lower than the upper end of the return path.

2. The method for starting up a resin pellet production device according to claim 1, wherein: In the water supply step, water is supplied to the water chamber while returning a portion of the particle cooling water ejected from the water tank by the pump to the water tank.

3. The method for starting up a resin pellet production device according to claim 1 or 2, wherein: In the water supply step, the particle cooling water is supplied to the water chamber via an auxiliary flow path having an inner diameter smaller than an inner diameter of the outward flow path and disposed in parallel with at least a portion of the outward flow path.

4. The method for starting up a resin pellet production device according to claim 3, wherein: The method further comprises: a rotating step, which is performed at least after the water supply step, of rotating the cutter while the cutter is in contact with the die plate; In the rotating step, the cutter is rotated while the particle cooling water is supplied to the water chamber via the auxiliary flow path.

5. The method for starting up a resin pellet production device according to claim 4, wherein: In the rotating step, the particle-cooling water is supplied to the water chamber and discharged through a discharge flow path that communicates the water chamber with the outside of the water chamber.

6. The method for starting up a resin pellet production device according to claim 5, wherein: In the rotating step, the amount of the particle cooling water discharged through the discharge flow path is adjusted so that the position of the water surface of the particle cooling water in the water chamber is maintained at the target water level.

7. The method for starting up a resin pellet production device according to claim 2, wherein: In the aforementioned water supply process, the aforementioned particle cooling water is supplied to the aforementioned water chamber by setting the flow path switching mechanism, which is arranged on the downstream side of the aforementioned pump in the aforementioned forward path and can switch between the first state, the second state and the third state, to the aforementioned first state. The first state is a state in which both the aforementioned water chamber and the aforementioned water tank are set as the delivery destination of the aforementioned particle cooling water, the second state is a state in which one of the aforementioned water chamber and the aforementioned water tank is set as the delivery destination of the aforementioned particle cooling water, and the third state is a state in which the other of the aforementioned water chamber and the aforementioned water tank is set as the delivery destination of the aforementioned particle cooling water.

8. The method for starting up a resin pellet production device according to claim 7, wherein: The return path includes: an upper connecting flow path connected to the upper part of the water chamber and extending upward; and an inclined flow path including a lower end connected to the upper connecting flow path, and inclined in a manner that the front end rises from the lower end to the upper end of the return path; In the water supply step, the target water level is set at a position lower than the lower end portion.

9. A method for producing resin pellets, which is a method for producing resin pellets in a resin pellet production device having a circulation flow path, wherein the circulation flow path has an outward path for pellet cooling water ejected from a water tank by a pump to reach a water chamber and a return path for the pellet cooling water to pass from the water chamber to the water tank via the upper side of the water chamber; the method for producing resin pellets is characterized in that: have: a water supply step of supplying the pellet cooling water stored in the water tank to the water chamber before starting the production of the resin pellets; a rotating step of rotating the cutter disposed in the water chamber while the cutter is in contact with a die plate having a plurality of die holes facing the water chamber; a heating step of heating the mold plate to melt the resin present inside the plurality of mold holes; A material supplying step of supplying a resin material from an upstream side to the mold plate; a manufacturing step of manufacturing the resin pellets by cutting the molten resin ejected from the plurality of die holes of the die plate with the cutter in the water chamber, and conveying the resin pellets from the water chamber while cooling the resin pellets with the pellet cooling water; and an operation stopping step of stopping heating of the die plate and stopping operation of the resin pellet production device while molten resin is present inside the plurality of die holes; In the water supply step, after the water chamber is filled with the particle cooling water, the supply of the particle cooling water is stopped so that the water level of the particle cooling water reaches a target water level set at a position lower than the upper end of the return path.

10. The method for producing resin particles according to claim 9, wherein In the rotating step, the water surface of the particle cooling water is maintained at the target water level, and the rotation speed of the cutter is set to be lower than the rotation speed of the cutter in the manufacturing step.

11. A resin pellet manufacturing device, characterized in that: have: A water tank, storing pellet cooling water; a water chamber, receiving the aforementioned particle cooling water from the aforementioned water tank; The outward path connects the aforementioned water tank with the aforementioned water chamber; A return path connects the water chamber to the water tank via the upper portion of the water chamber; A water supply unit supplies the particle cooling water from the water tank to the water chamber via the outgoing passage; a mold plate having a plurality of mold holes facing the water chamber; and A cutter is disposed in the water chamber and produces resin pellets by cutting the molten resin ejected from the plurality of die holes of the die plate in the water chamber; The water supply unit stops supplying the pellet cooling water when a water level of the pellet cooling water reaches a target water level set at a position lower than an upper end of the return path before starting production of the resin pellets.

12. The resin pellet production device according to claim 11, wherein: Also available: The first auxiliary flow path has an inner diameter smaller than the inner diameter of the forward flow path, and supplies the particle cooling water flowing out of the water tank to the water chamber; a return flow path branching from the outward flow path and connecting the outward flow path to the water tank; and A flow path switching mechanism for switching the delivery destination of the aforementioned particle cooling water; The first auxiliary flow path starts from the area between the water tank in the forward flow path and the flow path switching mechanism or the specified area in the return flow path, and ends at the area between the flow path switching mechanism in the forward flow path and the water chamber or the water chamber, and is opened when the particle cooling water is supplied to the water chamber before the start of the manufacture of the resin particles.

13. The resin pellet production device according to claim 12, wherein: further comprising a second auxiliary flow path having an inner diameter smaller than that of the outward flow path and different from the first auxiliary flow path; The second auxiliary flow path starts from the area between the water tank and the flow path switching mechanism in the forward path or a specified area in the return path and ends at the front end of the rotating shaft of the cutter, and is connected to the water chamber.

14. The resin pellet production device according to any one of claims 11 to 13, characterized in that: A discharge flow passage for discharging the particle cooling water from the water chamber to the outside of the water chamber is further provided.

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