Powder particle processing device and powder particle processing method
By utilizing the static pressure difference of dry air and pipeline open technology during the conveying of plastic granules, the problem of unstable dew point caused by air volume changes during the conveying process was solved, achieving low dew point at the conveying destination and stable air volume in the containment section, thus ensuring the quality of plastic products.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- KAWATA MFG
- Filing Date
- 2022-01-28
- Publication Date
- 2026-06-05
Smart Images
Figure CN114851430B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an apparatus and method for processing powders and granules of resin materials, etc. Background Technology
[0002] For example, in the manufacturing process of plastic products, a pre-drying process is carried out to remove moisture from the plastic granules (resin granules) before they are fed into the molding machine.
[0003] If plastic granules contain a certain level of moisture during melt molding, it will lead to unwanted thermal decomposition and gas formation. Therefore, it is desirable to melt-mold plastic granules in a state that is dried to a suitable level. Although plastic granules can be dried using a dryer before being fed into the molding machine, they may reabsorb moisture if exposed to a high-humidity atmosphere during the transfer of the dried granules from the dryer to the molding machine.
[0004] Figure 6 This is a diagram illustrating the structure of a conventional plastic product manufacturing equipment 201.
[0005] Manufacturing equipment 201 includes a drying device 202 for drying plastic granules, a molding machine 203 for melting and molding plastic granules into plastic articles, and a conveying system 204 for conveying plastic granules from the drying device 202 to the molding machine 203.
[0006] The drying apparatus 202 includes a drying hopper 205. A discharge port is formed at the lower end of the drying hopper 205, and a gate is provided for opening and closing the discharge port. With the gate closed, thus sealing the discharge port, plastic granules can be accumulated in the drying hopper 205. If the gate is opened from the state of plastic granules accumulating in the drying hopper 205, opening the discharge port, the plastic granules in the drying hopper 205 are discharged through the discharge port.
[0007] An air circulation line 206 is connected to the drying hopper 205. The air circulation line 206 connects to the inside of the drying hopper 205 at one end and the other end, and winds around the outside of the drying hopper 205. A drying blower 207 and a dehumidification and heating mechanism 208 are provided on the air circulation line 206. When the drying blower 207 is activated, air is blown from the drying blower 207 toward the dehumidification and heating mechanism 208. The air blown from the drying blower 207 passes through the dehumidification and heating mechanism 208, where the moisture contained in the air is removed, becoming low-dew-point dry air (dehumidified air). This air is further heated to become heated dry air, which is then supplied to the drying hopper 205 from one end of the air circulation line 206. Then, the dry air supplied to the drying hopper 205 removes moisture from the plastic particles accumulated in the drying hopper 205 and is discharged from the other end of the air circulation line 206. Thus, the plastic granules in the drying hopper 205 are dried.
[0008] A loading hopper 211 is disposed above the molding machine 203. Plastic granules are fed into the molding machine 203 from the loading hopper 211.
[0009] The conveying system 204 includes a closed-loop conveying line 212, a conveying blower 213, a discharge line 214, and a drying air branch line 215. The closed-loop conveying line 212 is connected to the loading hopper 211 at one and the other ends, and is wound around the outside of the loading hopper 211. The conveying blower 213 is mounted on the closed-loop conveying line 212. When the conveying blower 213 is activated, air circulates within the closed-loop conveying line 212, supplying air from one end of the closed-loop conveying line 212 into the loading hopper 211 and drawing air out of the loading hopper 211 from the other end of the closed-loop conveying line 212. One end of the discharge line 214 is connected to the outlet of the drying hopper 205, and the other end branches off and connects to the discharge side portion of the conveying blower 213 within the closed-loop conveying line 212. One end of the dry air branch line 215 is connected to the portion of the air circulation line 206 that supplies dry air from the dehumidification and heating mechanism 208, and branches off and connects to the discharge side of the delivery blower 213 in the closed-loop delivery line 212. A dry air valve 216 is installed on the dry air branch line 215.
[0010] When the conveying blower 213 is activated, if the gate of the drying hopper 205 is opened, the plastic particles in the drying hopper 205 are drawn out through the outlet of the drying hopper 205 and the discharge line 214 to the closed-loop conveying line 212, and then conveyed from the closed-loop conveying line 212 to the loading hopper 211. Furthermore, during this conveying process, the drying air valve 216 is opened, and low-dew-point dry air, after passing through the dehumidification and heating mechanism 208, is drawn into the closed-loop conveying line 212 from the air circulation line 206 through the drying air branch line 215. Thus, the closed-loop conveying line 212 and the loading hopper 211 maintain low humidity (low dew point), preventing the plastic particles accumulated in the loading hopper 211 from absorbing moisture.
[0011] Existing technical documents
[0012] Patent documents
[0013] Patent Document 1: Japanese Utility Model Application Publication No. 2-34212 Summary of the Invention
[0014] The technical problem that the invention aims to solve
[0015] However, since the dry air flows from the branch of the air circulation line 206 to the dry air branch line 215, the air volume of the dry air supplied from the air circulation line 206 to the dry hopper 205 changes temporarily during transport.
[0016] The purpose of this invention is to provide a powder processing device and a powder processing method that can lower the dew point of the powder's destination and stabilize the airflow in the container holding the powder.
[0017] Solution to the above technical problems
[0018] To achieve the above objectives, a powder processing apparatus and method according to one aspect of the present invention includes: a receiving section for receiving powder particles; a dry air supply section for supplying dehumidified and heated dry air to the receiving section; a conveying pipeline communicating with the receiving section and extending downstream of the powder particle delivery destination from the receiving section in the conveying direction relative to the delivery destination; a conveying airflow generating section for generating a conveying airflow in the conveying direction in the conveying pipeline; and a control section that, after the conveying airflow generated by the conveying airflow generating section has been used to convey the powder particles received in the receiving section to the delivery destination, opens the conveying pipeline to the atmosphere downstream of the delivery destination in the conveying direction and stops the generation of the conveying airflow generated by the conveying airflow generating section, thereby performing a low dew point treatment to reduce the dew point of the delivery destination.
[0019] According to this configuration, dehumidified and heated dry air is supplied to the containment chamber, where powder particles are dried. A conveying pipeline for transporting the dried powder particles to a destination is connected to the containment chamber, extending downstream of the destination in the conveying direction from the containment chamber. An airflow in the conveying direction is generated in the conveying pipeline, thereby transporting the powder particles contained in the containment chamber to the destination. After transporting the powder particles, a state is achieved where the conveying pipeline is opened to the atmosphere downstream of the destination in the conveying direction, and the airflow is stopped. In this state, because dry air is supplied to the containment chamber, the static pressure within the containment chamber becomes higher than the static pressure at the destination. Due to this static pressure difference, the dry air moves from the containment chamber to the destination via the conveying pipeline. As a result, a low dew point can be achieved at the destination. Furthermore, by stopping the generation of the airflow for delivery, dry air is not actively drawn out of the containment chamber into the delivery pipeline, and the dry air in the containment chamber does not undergo active fluctuations, thus preventing the airflow in the containment chamber from becoming unstable.
[0020] This allows for a lower dew point at the destination of the powder particles, while also preventing the airflow within the container that holds the powder particles from becoming unstable.
[0021] The dry air supply unit may be configured with the following components: a dry air pipeline connected to the housing; a drying airflow generating unit that generates an airflow in the dry air pipeline toward the housing; a dehumidification unit that dehumidifies the air flowing in the dry air pipeline; and a heating unit that heats the air flowing in the dry air pipeline.
[0022] According to this configuration, dehumidified and heated dry air can be supplied to the containment section.
[0023] The dehumidification unit is equipped with a drying zone and a regeneration zone. The drying air pipeline passes through the drying zone. The dehumidification unit may be composed of the following components: an adsorption cylinder, which is formed into a cylindrical shape and is arranged across the drying zone and the regeneration zone; a rotating part, which rotates the adsorption cylinder around its center line; and a regeneration air supply part, which supplies heated regeneration air to the regeneration zone.
[0024] According to this configuration, since the dry air pipeline passes through the drying zone, the air flowing through the dry air pipeline passes through the drying zone, and the moisture contained in the air passing through the drying zone is adsorbed by the adsorption cylinder. Thus, the air after passing through the drying zone is dehumidified into low-dew-point dry air, which then flows into the receiving section of the dry air pipeline. Since heated regeneration air is supplied to the regeneration zone, by rotating the adsorption cylinder, the portion of the air in the drying zone within the adsorption cylinder that has adsorbed moisture moves to the regeneration zone, thereby allowing the moisture to be removed from that portion and regenerating it to a low-humidity state.
[0025] The conveying pipeline can be configured to include: a first conveying pipeline connecting the downstream end of the conveying direction to the conveying destination; and a second conveying pipeline connecting the upstream end of the conveying direction to the conveying destination. The powder / granule handling device further includes a switching valve that connects the upstream end of the first conveying pipeline and the downstream end of the second conveying pipeline in the conveying direction, and can be switched to a circulating position and an open position. The circulating position connects the upstream end of the first conveying pipeline and the downstream end of the second conveying pipeline, and the open position closes the upstream end of the first conveying pipeline and opens the downstream end of the second conveying pipeline to the atmosphere.
[0026] Furthermore, the powder / granule handling apparatus may be configured to further include a dew point meter for detecting the dew point temperature at the destination of the transport.
[0027] The control unit can control the dry air supply unit to ensure that the dew point temperature at the destination reaches below 0°C, preferably below -20°C.
[0028] If the dew point temperature at the destination is below 0°C, preferably below -20°C, the moisture absorption of the powder particles at the destination can be effectively suppressed.
[0029] It can also be configured as a powder processing device that further includes an inert gas inlet for introducing inert gas into the containment.
[0030] In this configuration, by introducing an inert gas into the processing section, the powder particles can be dried in an inert gas atmosphere. As a result, it is possible to suppress the presence of oxidizing gases in the powder particles, and to suppress adverse phenomena such as yellowing of plastic products caused by the melting and molding of powder particles containing oxidizing gases.
[0031] If multiple transport destinations are provided, the powder and granule processing device can be further configured to include a transport destination switching unit that switches the transport pipeline through the transport destinations among the multiple transport destinations.
[0032] Another aspect of the present invention is a powder processing method comprising a device including a receiving section containing the powder and a conveying pipeline communicating with the receiving section and extending from the receiving section to a conveying destination of the powder in a conveying direction downstream of the receiving section from the receiving section. The method comprises: a drying step, supplying dehumidified and heated dry air to the receiving section containing the powder to dry the powder; a conveying step, after the drying step, generating a conveying airflow in the conveying pipeline in the conveying direction to convey the powder contained in the receiving section to the conveying destination; and a low dew point step, after the conveying step, opening the conveying pipeline to the atmosphere and stopping the generation of the conveying airflow downstream of the conveying destination, thereby lowering the dew point at the conveying destination.
[0033] According to this method, the same effect as that of the aforementioned powder and granular material processing device can be achieved.
[0034] Invention Effects
[0035] According to the present invention, the destination of the powder particles can be made to have a low dew point, and the air volume in the container holding the powder particles can be stabilized. Attached Figure Description
[0036] Figure 1 This is a diagram illustrating the configuration of a manufacturing apparatus that includes a powder processing device according to an embodiment of the present invention.
[0037] Figure 2 It is more than Figure 1 A simplified diagram showing the main components of the manufacturing equipment.
[0038] Figure 3 This is a flowchart illustrating the process of treatment following the drying process.
[0039] Figure 4 This is a diagram showing the configuration of a powder processing apparatus according to another embodiment.
[0040] Figure 5 This is a diagram showing the configuration of a powder processing apparatus according to another embodiment.
[0041] Figure 6 It is a diagram illustrating the structure of conventional plastic product manufacturing equipment. Detailed Implementation
[0042] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0043] <Manufacturing equipment for plastic products>
[0044] Figure 1 This is a diagram illustrating the configuration of a manufacturing apparatus 2 that includes a powder processing apparatus 1 according to an embodiment of the present invention.
[0045] The powder processing device 1 is a device included in the plastic product manufacturing equipment 2 for processing plastic particles and other powders that become raw materials for plastic products. Specifically, it is a device for drying the powders and conveying the dried powders to the molding machine 3.
[0046] The powder processing device 1 includes a drying hopper 11 and a loading hopper 12 disposed above the drying hopper 11. The powder, which is to be used as a raw material for plastic products, is supplied from the loading hopper 12 to the drying hopper 11, dried while contained (accumulated) in the drying hopper 11, and then conveyed from the drying hopper 11 to the molding machine 3.
[0047] Drying air for drying powder particles is supplied to the drying hopper 11 from the drying air line 13. One end of the drying air line 13 is disposed inside the drying hopper 11. The other end of the drying air line 13 is connected to an air exhaust pipe 14 that runs through the side wall of the drying hopper 11, and communicates with the inside of the drying hopper 11 via the air exhaust pipe 14. The drying air line 13 is wound around the outside of the drying hopper 11, and the drying filter 15, aftercooler 16, drying blower 17, adsorption unit 18, and drying heater 19 are sequentially installed from the other end of the drying air line 13, i.e., the air exhaust pipe 14, on the portion wound around the outside of the drying hopper 11.
[0048] The suction inlet of the dryer 17 is connected to one end of the discharge pipe 21. The other end of the discharge pipe 21 is connected to the air discharge pipe 14. A dryer filter 15 is installed in the middle of the discharge pipe 21 to remove foreign matter from the air flowing through the discharge pipe 21. The discharge pipe 21 passes through an aftercooler 16 between the dryer filter 15 and the dryer 17. The outlet of the dryer 17 is connected to one end of the first supply pipe 22.
[0049] The adsorption unit 18 includes an adsorber 23. The adsorber 23 has a configuration in which caps 25 are provided at both ends of a generally cylindrical adsorption cylinder 24. The adsorption cylinder 24 has a large number of airflow paths extending along its centerline. The inner surface of the airflow path (the surface in contact with air) is formed of an adsorbent material (e.g., zeolite) that adsorbs moisture. A first drying zone, a second drying zone, and a regeneration zone are provided in the area where the adsorption cylinder 24 exists. The airflow paths in the adsorption cylinder 24 include an airflow path existing in the first drying zone (hereinafter referred to as "first drying path"), an airflow path existing in the second drying zone (hereinafter referred to as "second drying path"), and an airflow path existing in the regeneration zone (hereinafter referred to as "regeneration path"). The cap 25 at one end of the adsorber 23 has a port 26A communicating with the first drying path, a port 26B communicating with the second drying path, and a port 26C communicating with the regeneration path. The cover 25 at the other end of the adsorber 23 is provided with a port 27A communicating with the first drying flow path, a port 27B communicating with the second drying flow path, and a port 27C communicating with the regeneration flow path. Furthermore, the adsorption unit 18 includes a rotation mechanism 28 that rotates the adsorption cylinder 24 about its centerline. The rotation mechanism 28 includes a motor 29 as a drive source.
[0050] Furthermore, the adsorption unit 18 includes a regeneration blower 31 and a regeneration heater 32. The intake of the regeneration blower 31 is open to the atmosphere through a regeneration filter 33. A regeneration pipeline 34 is connected to one end of the outlet of the regeneration blower 31. The middle section of the regeneration pipeline 34 passes through the aftercooler 16 and the regeneration heater 32 in sequence, and the other end is connected to port 27C of the adsorber 23. Thus, the regeneration pipeline 34 is connected to the regeneration flow path of the adsorption cylinder 24. The other port 26C, which is connected to the regeneration flow path, is open to the atmosphere.
[0051] The other end of the first supply pipe 22 is connected to port 26A of the adsorber 23, thus communicating with the first drying flow path. On the other hand, one end of the second supply pipe 35 is connected to port 27A, which communicates with the first drying flow path. The middle portion of the second supply pipe 35 passes through the drying heater 19, penetrates the side wall of the drying hopper 11, and its other end is disposed within the drying hopper 11. Within the drying hopper 11, the other end of the second supply pipe 35 bends downwards, forming a cone shape that expands towards the bottom. Furthermore, between the adsorption section 18 and the drying heater 19, a first return pipe 36 branches off and connects to the second supply pipe 35. The first return pipe 36 is connected to port 27B of the adsorber 23 and communicates with the second drying flow path of the adsorption cylinder 24. One end of the second return pipe 37 is connected to port 26B, which communicates with the second drying flow path. Between the aftercooler 16 and the dryer blower 17, the other end of the second return pipe 37 branches to the discharge pipe 21.
[0052] When the drying blower 17 is driven, air is blown from the outlet of the drying blower 17 into the first supply pipe 22, generating an airflow toward the adsorption section 18. This airflow flows from port 26A of the adsorber 23 into the first drying flow path of the adsorption cylinder 24, and then flows out from port 26B of the adsorber 23 to the second supply pipe 35. As the airflow passes through the first drying flow path, the moisture contained in the airflow is adsorbed by the adsorption cylinder 24, and the airflow after passing through the first drying flow path becomes a low dew point dry air flow. A portion of the airflow flowing out to the second supply pipe 35 flows into the first return pipe 36, from port 27B of the adsorber 23 into the second drying flow path, and then from port 26B of the adsorber into the second return pipe 37. When the airflow passes through the second drying flow path, the moisture contained in the airflow is adsorbed by the adsorption cylinder 24. The dew point temperature of the airflow after passing through the second drying flow path is further reduced, and it merges with the air flowing from the second return pipe 37 through the discharge pipe 21.
[0053] The dry air flowing through the second supply pipe 35 is heated by the drying heater 19, becoming heated dry gas, which is then supplied to the drying hopper 11. The temperature of the dry gas is, for example, 60–180°C. The dry gas blown out from the other end of the second supply pipe 35 passes through the powder particles accumulated in the drying hopper 11 and exits above the accumulated powder particles. As a result, the moisture in the powder particles is stripped away by the dry gas, and the powder particles are dried. The gas stripped of moisture from the powder particles is discharged through the air discharge pipe 14 to the discharge pipe 21, where it flows toward the drying blower 17.
[0054] On the other hand, the regeneration blower 31 is driven. When the regeneration blower 31 is driven, external gas is drawn into the intake port of the regeneration blower 31 through the regeneration filter 33. Then, the external gas is blown out from the outlet of the regeneration blower 31 to the regeneration line 34, where an airflow is generated toward the adsorption section 18. This airflow (external gas) flows into the regeneration path of the adsorption cylinder 24 from port 27C of the adsorber 23 after passing through the aftercooler 16 and the regeneration heater 32 in sequence, and is released to the atmosphere from port 26C of the adsorber 23 through the regeneration path. In the aftercooler 16, heat exchange occurs between the external gas flowing through the regeneration line 34 and the air flowing through the discharge line 21, the external gas flowing through the regeneration line 34 is heated, and the air flowing through the discharge line 21 is cooled. The external gas flowing through the regeneration line 34 is further heated by the regeneration heater 32 to become regeneration gas, which then passes through the regeneration path of the adsorption cylinder 24. On the other hand, the portion of the adsorbent that has adsorbed moisture from the air in the dry zone of the adsorption cylinder 24 moves to the regeneration zone along with the rotation of the adsorption cylinder 24 caused by the rotating mechanism 28. Thus, the moisture adsorbed by the adsorption cylinder 24 is released from the adsorption cylinder 24, and the adsorption cylinder 24 is regenerated to a low-humidity state. To allow moisture to be released from the adsorption cylinder 24, the temperature of the regeneration gas is set to, for example, 180–250°C.
[0055] The lower part of the drying hopper 11 is formed into a cone shape that tapers downwards at the front end, and a discharge port 41 is formed at its lower end. The drying hopper 11 is provided with a gate 42 for opening and closing the discharge port 41. With the gate 42 closed, thus sealing the discharge port 41, powder supplied from the loading hopper 12 can be accumulated. A discharge branch pipe 43 is connected to the discharge port 41. The discharge branch pipe 43 is installed in the conveying line 44. If the gate 42 is opened from the state where powder is accumulated in the drying hopper 11, opening the discharge port 41, the powder in the drying hopper 11 is discharged from the discharge port 41 to the discharge branch pipe 43.
[0056] The delivery line 44 includes a switching valve 45, a first delivery line 46, and a second delivery line 47.
[0057] The switching valve 45 has an input port 51, a circulating output port 52, and an atmospheric open port 53. The switching valve 45 is equipped with valve bodies that allow the circulating output port 52 and the atmospheric open port 53 to open and close independently. The switching valve 45 switches between a circulating position and an open position based on the positions of these valve bodies. In the circulating position, the atmospheric open port 53 is closed, and the circulating output port 52 is open, connecting the input port 51 and the circulating output port 52 within the valve box. In the open position, the circulating output port 52 is closed, and the atmospheric open port 53 is open, connecting the input port 51 and the atmospheric open port 53 within the valve box.
[0058] One end of the first conveying pipe 46 is connected to the circulation output port 52 of the switching valve 45. Above the forming machine 3, there is a conveying destination hopper 54 for accumulating the powder particles to be fed into the forming machine 3. The other end of the first conveying pipe 46 is connected to the side wall of the conveying destination hopper 54 and communicates with the inside of the conveying destination hopper 54.
[0059] One end of the second conveying pipe 47 is connected to the upper wall of the destination hopper 54 and communicates with the inside of the destination hopper 54. The other end of the second conveying pipe 47 is connected to the input port 51 of the switching valve 45. The primary and secondary switching valves 55, the cyclone dust collector 56, the conveying filter 57, and the conveying blower 58 are installed sequentially on the second conveying pipe 47 from the side of the destination hopper 54.
[0060] The primary / secondary switching valve 55 has a primary input port 61, a secondary input port 62, and an output port 63. The primary / secondary switching valve 55 is equipped with valve bodies that independently open and close the primary input port 61 and the secondary input port 62. The primary / secondary switching valve 55 switches between a primary delivery position and a secondary delivery position based on the positions of these valve bodies. In the primary delivery position, the secondary input port 62 is closed, and the primary input port 61 is open, connecting the primary input port 61 to the output port 63 within the valve housing. In the secondary delivery position, the primary input port 61 is closed, and the secondary input port 62 is open, connecting the secondary input port 62 to the output port 63 within the valve housing.
[0061] The second conveying conduit 47 is further subdivided into a first conduit section 71, a second conduit section 72, a third conduit section 73, a fourth conduit section 74, and a fifth conduit section 75. One end of the first conduit section 71 serves as one end of the second conveying conduit 47 and is connected to the upper wall of the conveying destination hopper 54. The other end of the first conduit section 71 is connected to the secondary input port 62 of the primary / secondary switching valve 55. One end of the second conduit section 72 is connected to the output port 63 of the primary / secondary switching valve 55, and the other end of the second conduit section 72 is connected to the air inlet section 76 of the cyclone dust collector 56. One end of the third conduit section 73 is connected to the suction section 77 of the cyclone dust collector 56, and the other end of the third conduit section 73 is connected to the inlet 78 of the conveying filter 57. One end of the fourth conduit section 74 is connected to the outlet 79 of the conveying filter 57, and the other end of the fourth conduit section 74 is connected to the suction port of the conveying blower 58. One end of the fifth conduit 75 is connected to the outlet of the delivery blower 58, and the other end of the fifth conduit 75 is connected to the input port 51 of the switching valve 45.
[0062] Furthermore, a primary suction line 81 is connected to one end of the upper wall of the loading hopper 12, and the primary suction line 81 communicates with the inside of the loading hopper 12. The other end of the primary suction line 81 is connected to the primary input port 61 of the primary / secondary switching valve 55. A powder supply line 82 is connected to one end of the side wall of the loading hopper 12. The powder supply line 82 extends toward a raw material tank (not shown) containing powder, and its other end is connected to a suction pipe 83 disposed inside the raw material tank.
[0063] When supplying powder from the raw material tank to the loading hopper 12, the switching valve 45 is set to the open position, and the single / double switching valve 55 is set to the single-feed position. If the conveying blower 58 is driven, air is drawn from the fourth pipeline section 74 to the suction port of the conveying blower 58, and this air is blown out from the blow outlet of the conveying blower 58 to the fifth pipeline section 75. The air blown out to the fifth pipeline section 75 enters the valve box of the switching valve 45 from the input port 51, and is released to the atmosphere from the valve box through the atmospheric opening port 53. As a result, a negative pressure is generated in the single suction line 81, the second pipeline section 72, the third pipeline section 73, and the fourth pipeline section 74. Through this negative pressure, the powder in the raw material tank is sucked up by the suction pipe 83 and supplied to the loading hopper 12 through the powder supply line 82.
[0064] <Transportation and Low Dew Point Treatment>
[0065] Figure 2 It is more than Figure 1 A simplified diagram showing the main components of manufacturing equipment 2.
[0066] A dew point meter 91 is installed in the destination hopper 54 to detect the value corresponding to the amount of moisture contained in the air in the destination hopper 54, which is the dew point temperature.
[0067] Furthermore, the powder and particulate matter processing apparatus 1 includes a control unit 92. The control unit 92 is equipped with a microcontroller unit (micro control unit), which incorporates non-volatile memory such as a CPU and flash memory, as well as volatile memory such as DRAM (Dynamic Random Access Memory). The control unit 92 receives detection signals from the dew point meter 91. Based on the dew point temperature detected by the dew point meter 91, the control unit 92 controls the operation of each part of the powder and particulate matter processing apparatus 1.
[0068] Figure 3 This is a flowchart illustrating the process of treatment following the drying process.
[0069] In the drying process, as mentioned above, drying gas is supplied to the drying hopper 11, and the powder particles accumulated in the drying hopper 11 are dried.
[0070] After the drying process, the system is subjected to closed-loop conveying via the control unit 92 (step S1).
[0071] In the closed-loop conveying process, the switching valve 45 is set to the circulation position, and the first-pass / second-pass switching valve 55 is set to the second-pass conveying position. Then, the conveying blower 58 is driven. When the conveying blower 58 is driven, air is drawn from the fourth pipe section 74 to the suction port of the conveying blower 58, and the fourth pipe section 74 becomes negative pressure. Through this negative pressure, air in the destination hopper 54 is drawn out to the first pipe section 71, and an airflow is generated in the first pipe section 71, the second pipe section 72, the third pipe section 73, and the fourth pipe section 74. On the other hand, air blown from the outlet of the conveying blower 58 to the fifth pipe section 75 enters the valve box of the switching valve 45 from the input port 51 of the switching valve 45, and flows out from the circulation output port 52 of the switching valve 45 to the first conveying pipe 46. Thus, a conveying airflow is generated by the air circulating in the conveying pipeline 44 composed of the switching valve 45, the first conveying pipe 46, and the second conveying pipe 47. If the gate 42 of the drying hopper 11 is opened and the outlet 41 of the drying hopper 11 is opened, the powder particles in the drying hopper 11 are sucked out from the outlet 41 to the conveying pipeline 44. The powder particles are conveyed to the conveying destination hopper 54 in the conveying pipeline 44 (first conveying pipeline 46) along with the conveying airflow.
[0072] On the other hand, during the conveying of powder particles, dry air is also supplied to the drying hopper 11. At this time, the drying blower 17, the adsorption section 18 and the drying heater 19 are controlled so that the dew point temperature detected by the dew point meter 91 reaches below 0°C, preferably below -20°C.
[0073] Dust and other foreign matter contained in the conveying airflow are captured as the airflow passes through cyclone dust collectors 56 and 57. In cyclone dust collector 56, air is drawn from the suction section 77 to the third pipe section 73, thereby creating a negative pressure inside cyclone dust collector 56. Through this negative pressure, air (the conveying airflow) is drawn into cyclone dust collector 56 from the second pipe section 72 via the air inlet section 76. Inside cyclone dust collector 56, the air swirls, and the air and foreign matter are separated due to centrifugal force and gravity. The foreign matter accumulates in the collection box connected to the lower end of cyclone dust collector 56.
[0074] Through closed-loop conveying, the powder particles in the drying hopper 11 are conveyed to the destination hopper 54. If the powder particles disappear in the drying hopper 11, the control unit 92 performs low dew point treatment (step S2).
[0075] During the low dew point treatment, the drive of the conveying blower 58 is stopped. Then, the switching valve 45 is switched from the circulation position to the open position. As a result, the conveying line 44 is opened to the atmosphere via the atmospheric open port 53 of the switching valve 45. The first and second switching valve 55 remains in the second conveying position. At this time, dry air continues to be supplied to the drying hopper 11, and the drying blower 17, the adsorption section 18, and the drying heater 19 are controlled to bring the dew point temperature detected by the dew point meter 91 to below 0°C, preferably below -20°C.
[0076] Because dry air is supplied to the drying hopper 11, the static pressure inside the drying hopper 11 becomes higher than the static pressure inside the destination hopper 54. Due to this pressure difference, the dry air moves from the drying hopper 11 to the destination hopper 54 via the conveying line 44 (first conveying line 46). As a result, the dew point inside the destination hopper 54 is lowered. At this time, only a small amount of dry air branches off to the destination hopper 54 side and therefore has no effect.
[0077] Additionally, the amount of dry air released through the opening is replenished by external air to adjust the pressure on the drying hopper 11 side. For example, external air can be drawn in through the powder supply line 82 on the primary side. Alternatively, a supply port for replenishing air (external air) to any of the drying air lines 13 can be provided; in this case, a supply port is preferably provided upstream of the adsorption section 18. Furthermore, it is not limited to external air; pre-dehumidified dry air can also be used as a supplement.
[0078] <Effect>
[0079] As described above, the dew point inside the destination hopper 54 can be kept low. By keeping the dew point inside the destination hopper 54 low, moisture absorption by the powder particles can be suppressed. By controlling the dew point temperature inside the destination hopper 54 to below 0°C, preferably below -20°C, moisture absorption by the powder particles can be effectively suppressed inside the destination hopper 54. As a result, unwanted thermal decomposition and gas generation during the melting and forming of the powder particles by the forming machine 3 can be suppressed.
[0080] Furthermore, by stopping the generation of the airflow for conveying, the dry air will not be actively drawn out from the drying hopper 11 to the conveying pipeline 44, and the dry air in the drying hopper 11 will not undergo active fluctuations. Therefore, the airflow in the drying hopper 11 can be stabilized, and the temperature control in the drying hopper 11 can be prevented from becoming unstable.
[0081] Therefore, it is possible to lower the dew point in the destination hopper 54, while also preventing the airflow and temperature control in the drying hopper 11 from becoming unstable.
[0082] <Another implementation method>
[0083] Figure 4 This is a diagram illustrating the configuration of a powder / granule processing apparatus 101 according to another embodiment. Figure 4 In the middle, equivalent to Figure 2 The parts shown are given the same reference numerals as those parts. Furthermore, the following refers to… Figure 4 The configuration shown applies only to... Figure 2 The differences in the configuration shown will be explained.
[0084] like Figure 4 As shown, alternatively, the nitrogen supply line 102 can branch off and connect to the dry air line 13, through which nitrogen generated by the nitrogen generating device 103 can be introduced. In the nitrogen generating device 103, air compressed by the air compressor 104 is supplied to the adsorption tank 105, where the oxygen and moisture contained in the compressed air are adsorbed, thereby generating nitrogen gas with a high concentration of nitrogen.
[0085] In this configuration, by introducing nitrogen into the dry air, the drying hopper 11 becomes a nitrogen atmosphere, enabling the powder to be dried in this inert gas atmosphere. As a result, it is possible to suppress the presence of oxidizing gases in the powder, and to suppress adverse phenomena such as yellowing of plastic products caused by the melting and molding of powder containing oxidizing gases.
[0086] Figure 5 This is a diagram showing the configuration of a powder / granule processing apparatus 111 according to another embodiment. Figure 5 In the middle, the same applies to the equivalent Figure 2 The parts shown are given the same reference numerals as these parts, and descriptions of the parts given the same reference numerals are omitted.
[0087] exist Figure 2 In the configuration shown, with the switching valve 45 installed between the first delivery line 46 and the second delivery line 47 and the switching valve 45 set to the circulation position, the delivery line 44 becomes a closed-loop delivery line by setting the second delivery line 47 (the fifth line section 75) to the first delivery line 46 via the switching valve 45.
[0088] like Figure 5 As shown, the switching valve 45 is omitted. An on / off valve 112 is provided at the downstream end of the direction of airflow (conveying direction) in the second conveying pipeline 47. During the drying process, the on / off valve 112 is closed. After the drying process, the powder particles are conveyed from the drying hopper 11 to the conveying destination hopper 54, and the dew point in the conveying destination hopper 54 is reduced. The on / off valve 112 can also be opened.
[0089] By configuring the powder processing device 111, it is possible to achieve the same effect as the configuration of the powder processing device 1.
[0090] <Variation Example>
[0091] The above describes several embodiments of the present invention, but the present invention can also be implemented in other ways.
[0092] For example, in Figure 2 In the configuration shown, the operation of the powder and particulate matter processing device 1 is controlled based on the dew point measured using the dew point meter 91, but it is not limited to this and the dew point meter 91 may be omitted. In this case, for example, the time for switching the switching valve 41 to the open position may be predetermined to a range where low dew point can be achieved, and only time control is performed.
[0093] It is also possible to use a heated conveyor hopper 54 to the destination. This method is advantageous because it allows for low dew point treatment even without a heating mechanism, as it reduces equipment costs. However, it can be used to improve the effectiveness of low dew point treatment for materials that are highly hygroscopic or for which maintaining low moisture content is strictly required.
[0094] In addition, Figure 5 In the configuration shown, a check valve that prevents external gas from being drawn into the second delivery pipeline 47 can be installed instead of the on / off valve 112.
[0095] In addition, the on / off valve 112 or the check valve that replaces it can also be installed on the upstream side of the conveying blower 58, as long as it is located downstream of the conveying destination hopper 54 in the direction of airflow for conveying.
[0096] The blower 58 is not limited to being installed in the second delivery line 47, but can also be installed in the first delivery line 46.
[0097] In addition, such as Figure 1 As shown by the dashed lines, the manufacturing equipment 2 may also include multiple forming machines 3. For example, in a configuration where the manufacturing equipment 2 includes two forming machines 3, a secondary input port 64 is added to the primary / secondary switching valve 55. A branch pipe 65 branching from the first conveying pipe 46 is connected to the side wall of the conveying destination hopper 54 of the additional forming machine 3. One end of the sixth pipe section 66 is connected to the upper wall of the conveying destination hopper 54, and the other end of the sixth pipe section 66 is connected to the secondary input port 64. Then, when conveying powder to the additional forming machine 3, the primary input port 61 and the secondary input port 62 of the primary / secondary switching valve 55 are closed, and the valve is switched to a position where the secondary input port 64 is connected to the output port.
[0098] In addition, various design changes may be made to the above-described configuration within the scope of the claims.
[0099] Explanation of reference numerals in the attached figures
[0100] 1, 101, 111 Powder and Granular Material Processing Device
[0101] 11. Drying hopper (receiving section)
[0102] 13 Dry air pipeline
[0103] 17. Drying blower (airflow generating unit for drying)
[0104] 18. Adsorption section (dehumidification section)
[0105] 19. Drying heater (heating section)
[0106] 24 Adsorption tube
[0107] 28 Rotating mechanism (rotating part)
[0108] 31. Regenerated Hair Dryer (Regenerated Air Supply Unit)
[0109] 32. Regenerative heater (regenerative air supply unit)
[0110] 34. Regeneration pipeline (regenerated air supply unit)
[0111] 44 Delivery pipeline
[0112] 45 Switching valve
[0113] 46 First delivery pipeline
[0114] 47. Second delivery pipeline
[0115] 58. Conveyor blower (airflow generating unit for conveying)
[0116] 91 Dew Point Meter
[0117] 92. Control Department.
Claims
1. A powder / granule processing device, characterized in that, Include: The receiving section contains the powder particles; The dry air supply unit supplies dehumidified and heated dry air to the receiving section. A conveying pipeline, communicating with the containment, extends from the containment via a conveying destination of powder particles from the containment, and further extends from the conveying destination to the downstream side of the conveying direction, wherein the conveying direction is from the containment toward the conveying destination; The airflow generating unit for conveying generates airflow for conveying in the conveying direction in the conveying pipeline; After the conveying airflow generated by the conveying airflow generator has been used to convey the powder contained in the container to the conveying destination, the control unit opens the conveying pipeline to the atmosphere on the downstream side of the conveying direction relative to the conveying destination and stops the generation of the conveying airflow by the conveying airflow generator. Dry air is then supplied to the container by the dry air supply unit. By creating such a state, a low dew point treatment is performed to reduce the dew point of the conveying destination.
2. The powder and granular material processing device as described in claim 1, characterized in that, The dry air supply unit includes: A dry air pipeline is connected to the interior of the receiving section; A drying airflow generating unit generates an airflow in the direction of the receiving part from the drying air pipeline; The dehumidification unit dehumidifies the air flowing through the dry air duct. The heating unit heats the air flowing through the dry air pipeline.
3. The powder and granular material processing device as described in claim 2, characterized in that, The dehumidification unit includes a drying area and a regeneration area. The dry air pipeline passes through the drying area. The dehumidification unit includes: An adsorption cylinder, formed in a cylindrical shape, is disposed spanning the drying area and the regeneration area; The rotating part causes the adsorption cylinder to rotate around its center line; The regenerated air supply unit supplies heated regenerated air to the regeneration area.
4. The powder / granular material processing apparatus according to any one of claims 1 to 3, characterized in that, The delivery pipeline includes: The first conveying pipeline connects the downstream end of the conveying direction to the conveying destination; The second delivery pipeline connects the upstream end in the delivery direction to the delivery destination. The system further includes a switching valve that connects the upstream end of the first conveying pipeline in the conveying direction and the downstream end of the second conveying pipeline in the conveying direction. The switching valve can be switched to a circulating position and an open position. The circulating position connects the upstream end of the first conveying pipeline with the downstream end of the second conveying pipeline, while the open position closes the upstream end of the first conveying pipeline and opens the downstream end of the second conveying pipeline to the atmosphere.
5. The powder / granular material processing apparatus according to any one of claims 1 to 3, characterized in that, It further includes a dew point meter for detecting the dew point temperature at the destination of the transport.
6. The powder / granular material processing apparatus according to any one of claims 1 to 3, characterized in that, The control unit controls the dry air supply unit to bring the dew point temperature at the destination below 0°C.
7. The powder / granular material processing apparatus according to any one of claims 1 to 3, characterized in that, It further includes an inert gas inlet section to introduce inert gas into the containment section.
8. The powder / granule processing apparatus according to any one of claims 1 to 3, characterized in that, Multiple delivery destinations are specified. It further includes a delivery destination switching unit that switches the delivery destination through which the delivery pipeline passes among a plurality of delivery destinations.
9. A method for processing powder particles, comprising a receiving portion for accommodating the powder particles and a conveying pipeline, wherein the conveying pipeline is in communication with the receiving portion, extends from the receiving portion via a conveying destination of the powder particles from the receiving portion and further extends downstream of the conveying destination in a conveying direction, wherein the conveying direction is from the receiving portion toward the conveying destination, characterized in that... Include: In the drying process, dehumidified and heated dry air is supplied to the container that holds the powder particles to dry the powder particles. In the conveying process, after the drying process, the conveying pipeline generates a conveying airflow in the conveying direction to convey the powder particles contained in the receiving section to the conveying destination. In the low dew point process, after the conveying process, the conveying pipeline is opened to the atmosphere and the generation of the conveying airflow is stopped on the downstream side of the conveying direction compared to the conveying destination, while dry air continues to be supplied to the containment, thereby creating a state in which the conveying destination is made low dew point.