JP2022120722A - Granule processing device, and granule processing method - Google Patents

Abstract

To provide a granule processing device and a granule processing method, capable of stabilizing an air flow rate in a storage storing granules, while capable of making the dewpoint in a granule transport destination lower.SOLUTION: Granules stored in a drying hopper 11 is dried by supplying the drying hopper 11 with dehumidified and heated dry air. A transport line 44 for transporting dried granules to a transport destination hopper 54, communicates with the drying hopper 11 and is extended downstream relative to the transport destination hopper 54 via the transport destination hopper 54 in the transport direction of a transport air stream flowing from the drying hopper 11. By generating a transport air stream flowing in the transport direction in the transport line 44, the granules stored in the drying hopper 11 is transported to the transport destination hopper 54. Subsequent to transporting the granules, the transport line 44 is opened to the atmosphere at downstream side in the transport direction relative to the transport destination hopper 54, and a state of stopping generating a transport air stream is formed.SELECTED DRAWING: Figure 2

Description

The present invention relates to an apparatus and method for processing granular materials such as resin materials.

For example, in the manufacturing process of plastic products, pre-drying is performed to remove water from plastic pellets (resin pellets), which are raw materials for plastic products, before they are put into a molding machine.

If the plastic pellets contain more than a certain amount of moisture when they are melt-molded, it will cause unnecessary thermal decomposition and gas generation. It is desirable that A dryer can be used to dry the plastic pellets before they are put into the molding machine. May absorb moisture again if exposed.

FIG. 6 is a diagram schematically showing the configuration of a conventional plastic product manufacturing facility 201. As shown in FIG.

The manufacturing facility 201 includes a drying device 202 that dries plastic pellets, a molding machine 203 that melts the plastic pellets to mold plastic products, and a transportation system 204 that transports the plastic pellets from the drying device 202 to the molding machine 203. included.

The drying device 202 has a drying hopper 205 . A discharge port is formed at the lower end of the drying hopper 205, and a gate shutter for opening and closing the discharge port is provided. With the gate shutter closed and the outlet closed, the plastic pellets can be stored in the drying hopper 205 . When the gate shutter is opened from the state in which the plastic pellets are stored in the drying hopper 205 to open the discharge port, the plastic pellets in the drying hopper 205 are discharged through the discharge port.

An air circulation line 206 is connected to the drying hopper 205 . The air circulation line 206 communicates with the inside of the drying hopper 205 at one end and the other end, and is routed outside the drying hopper 205 . A drying blower 207 and a dehumidifying/heating mechanism 208 are provided on the air circulation line 206 . When the drying blower 207 is driven, air is blown out from the drying blower 207 toward the dehumidification/heating mechanism 208 . The air blown out from the drying blower 207 passes through the dehumidifying/heating mechanism 208, whereupon the moisture contained in the air is removed by the dehumidifying/heating mechanism 208, resulting in low dew point dry air (dehumidified air). , and becomes dry air heated by heating, and is supplied into the drying hopper 205 from one end of the air circulation line 206 . The dry air supplied into the drying hopper 205 removes moisture from the plastic pellets stored in the drying hopper 205 and is discharged from the other end of the air circulation line 206 into the air circulation line 206 . This dries the plastic pellets in the drying hopper 205 .

A loader hopper 211 is arranged above the molding machine 203 . The molding machine 203 is loaded with plastic pellets from a loader hopper 211 .

Transport system 204 includes closed loop transport line 212 , transport blower 213 , exhaust line 214 and dry air branch line 215 . The closed-loop transport line 212 communicates with the inside of the loader hopper 211 at one end and the other end, and is routed outside the loader hopper 211 . A transport blower 213 is provided on the closed loop transport line 212 . When the transport blower 213 is driven, air circulates in the closed loop transport line 212, the air is supplied into the loader hopper 211 from one end of the closed loop transport line 212, and the air in the loader hopper 211 is sucked from the other end of the closed loop transport line 212. served. The discharge line 214 has one end connected to the discharge port of the drying hopper 205 and the other end branched and connected to a portion of the closed loop transport line 212 on the discharge side of the transport blower 213 . One end of the dry air branch line 215 is connected to a portion of the air circulation line 206 through which the dry air from the dehumidifying/heating mechanism 208 flows, and is branched and connected to a portion of the closed loop transport line 212 on the discharge side of the transport blower 213 . It is A dry air valve 216 is interposed in the dry air branch line 215 .

When the gate shutter of the drying hopper 205 is opened while the transport blower 213 is being driven, the plastic pellets in the drying hopper 205 are sucked out to the closed loop transport line 212 through the outlet of the drying hopper 205 and the discharge line 214, Transported on closed loop transport line 212 to loader hopper 211 . During transportation, the dry air valve 216 is opened, and dry air with a low dew point after passing through the dehumidification/heating mechanism 208 is taken into the closed loop transportation line 212 from the air circulation line 206 through the dry air branch line 215. . As a result, the closed-loop transport line 212 and the inside of the loader hopper 211 are kept at low humidity (low dew point), and the plastic pellets stored inside the loader hopper 211 can be prevented from absorbing moisture.

Japanese Utility Model Laid-Open No. 2-34212

However, as the dry air branches from the air circulation line 206 to the dry air branch line 215, the amount of dry air supplied from the air circulation line 206 into the drying hopper 205 temporarily changes during transportation.

An object of the present invention is to provide a granular material processing apparatus and a granular material processing method that are capable of stabilizing the air volume in a storage section in which the granular material is stored while reducing the dew point of the transportation destination of the granular material. is.

In order to achieve the above object, a granular material processing apparatus and a granular material processing method according to one aspect of the present invention include a container for containing powder and a dehumidified and heated A dry air supply unit that supplies dry air communicates with the interior of the storage unit, and extends downstream of the transportation destination from the storage unit in the transportation direction toward the transportation destination via the transportation destination of the granular material from the storage unit. A transportation line, a transportation airflow generation unit that generates an airflow for transportation in the transportation direction in the transportation line, and an airflow for transportation is generated by the airflow generation unit for transportation, and the powder and granules stored in the storage unit are transported to the destination. to create a state in which the transportation line is open to the atmosphere downstream of the transportation destination in the transportation direction, and the generation of the transportation airflow by the transportation airflow generation unit is stopped after the transportation processing is performed. and a control unit that performs dew point reduction processing for reducing the dew point of the transportation destination.

According to this configuration, the dehumidified and heated dry air is supplied into the storage section, thereby drying the granular material stored in the storage section. The transport line for transporting the dried powdery material to the destination communicates with the inside of the container and extends downstream of the destination in the transport direction from the container to the destination via the destination. . By generating a transportation air current in the transportation direction in the transportation line, the granular material stored in the storage section is transported to the transportation destination. Then, after the powder or granular material is transported, a state is created in which the transport line is opened to the atmosphere downstream of the transport destination in the transport direction and the generation of the transport airflow is stopped. In this state, since dry air is supplied to the storage section, the static pressure inside the storage section becomes higher than the static pressure at the transportation destination. Due to the static pressure difference, the dry air moves from inside the container through the transport line to the transport destination. As a result, the dew point of the transportation destination can be lowered. In addition, since the generation of the transportation airflow is stopped, the dry air is not actively sucked out from the storage section to the transportation line, and the dry air in the storage section does not actively fluctuate. It is possible to suppress the air volume from becoming unstable.

Therefore, it is possible to reduce the dew point of the transportation destination of the granular material, while suppressing the unstable air volume in the accommodation section in which the granular material is accommodated.

The dry air supply unit includes a dry air line that communicates with the interior of the storage unit, a dry air flow generation unit that generates an air flow in the dry air line in a direction toward the storage unit, and a dehumidification unit that dehumidifies the air flowing through the dry air line. and a heating unit for heating the air flowing through the drying air line.

With this configuration, dehumidified and heated dry air can be supplied into the housing.

A drying area and a regeneration area are set in the dehumidification section, a drying airline passes through the drying area, and the dehumidification section is formed in a cylindrical shape and straddles the drying area and the regeneration area. Therefore, a configuration may be provided that includes an adsorption cylinder arranged in this manner, a rotating part that rotates the adsorption cylinder around its center line, and a regeneration air supply part that supplies heated regeneration air to the regeneration region.

According to this configuration, since the dry air line passes through the dry area, the air flowing through the dry air line passes through the dry area. is adsorbed to As a result, the air that has passed through the drying area becomes dry air with a low dew point due to dehumidification, and flows through the drying air line toward the interior of the housing. Since heated regeneration air is supplied to the regeneration region, the adsorption column is rotated to move the portion of the adsorption column that has adsorbed moisture from the air in the dry region to the regeneration region, thereby removing moisture from that portion. It can be desorbed and the part can be regenerated to a low humidity condition.

The transport line includes a first transport pipeline whose downstream end in the transport direction is connected to the transport destination, and a second transport pipeline whose upstream end in the transport direction is connected to the transport destination. , the upstream end in the transportation direction of the first transportation pipeline and the downstream end in the transportation direction of the second transportation pipeline are connected, and the upstream end of the first transportation pipeline and the downstream end of the second transportation pipeline are connected. and an open position that closes the upstream end of the first transport pipeline and opens the downstream end of the second transport pipeline to the atmosphere.

Further, the granular material processing apparatus may further include a dew point meter for detecting the dew point temperature at the transportation destination.

The control unit may control the dry air supply unit so that the dew point temperature at the transportation destination is 0° C. or lower, preferably −20° C. or lower.

If the dew point temperature at the transportation destination is 0° C. or lower, preferably −20° C. or lower, the moisture absorption of the granular material at the transportation destination can be suppressed satisfactorily.

The granular material processing apparatus may further include an inert gas introducing section for introducing an inert gas into the accommodating section.

In this configuration, by introducing the inert gas into the processing section, the powder can be dried in the inert gas atmosphere. As a result, it is possible to suppress the oxidizing gas from being contained in the granules, and to suppress the occurrence of problems such as yellowing of plastic products due to the melting and molding of the granules containing the oxidizing gas.

A plurality of transportation destinations may be set, and the granular material processing apparatus may further include a transportation destination switching unit for switching a transportation destination through which the transportation line passes among the plurality of transportation destinations.

A powdery or granular material processing method according to another aspect of the present invention includes: a storage unit that stores powdery or granular material therein; and a transport line extending downstream in the transport direction from the container to the destination, wherein the powder is dehumidified and heated in the container containing the powder. A drying process in which dry air is supplied to dry the powder, and after the drying process, an air flow for transport in the transport direction is generated in the transport line to transport the powder contained in the container to the transport destination. After the transportation process, the transportation line is opened to the atmosphere downstream of the transportation destination in the transportation direction, and the generation of the transportation airflow is stopped, thereby reducing the transportation destination to a low dew point and a low dew point step.

According to this method, it is possible to obtain the same effects as those of the powder processing apparatus described above.

ADVANTAGE OF THE INVENTION According to this invention, the air volume in the accommodating part in which a granular material is accommodated can be stabilized, while the dew point of the transportation destination of a granular material can be made low.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows diagrammatically the structure of the manufacturing equipment containing the granular material processing apparatus which concerns on one Embodiment of this invention. FIG. 2 is a diagram showing the essential configuration of the manufacturing equipment in a more simplified manner than in FIG. 1; It is a flowchart which shows the flow of the process performed after a drying process. It is a figure which shows the structure of the granular material processing apparatus which concerns on other embodiment. It is a figure which shows the structure of the granular material processing apparatus which concerns on further another embodiment. It is a figure which shows diagrammatically the structure of the manufacturing equipment of the conventional plastic product.

BEST MODE FOR CARRYING OUT THE INVENTION Below, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Manufacturing equipment for plastic products>
FIG. 1 is a diagram schematically showing the configuration of manufacturing equipment 2 including a granular material processing apparatus 1 according to one embodiment of the present invention.

The granular material processing apparatus 1 is a device that is included in a plastic product manufacturing facility 2 and processes granular materials such as plastic pellets that are raw materials for plastic products. Specifically, the granular material is dried. It is a device for transporting the dried granular material to the molding machine 3.

The granular material processing apparatus 1 includes a drying hopper 11 and a loader hopper 12 arranged above the drying hopper 11 . Granules, which are raw materials for plastic products, are supplied from the loader hopper 12 to the drying hopper 11, dried in the drying hopper 11, and then transported from the drying hopper 11 to the molding machine 3. be.

Dry air is supplied from a drying air line 13 into the drying hopper 11 for drying the granular material. One end of the drying air line 13 is arranged inside the drying hopper 11 . The other end of the drying air line 13 is connected to an air discharge pipe 14 provided through the side wall of the drying hopper 11 and communicates with the interior of the drying hopper 11 via the air discharge pipe 14 . The drying air line 13 is routed outside the drying hopper 11, and in the portion routed outside the drying hopper 11, there are a drying filter 15, an aftercooler 16, a drying blower 17, an adsorption section 18 and a drying heater 19. They are interposed in that order from the other end side of the airline 13, that is, from the air discharge pipe 14 side.

One end of a discharge pipe 21 is connected to the suction port of the drying blower 17 . The other end of the discharge line 21 is connected to the air discharge pipe 14 . The dry filter 15 is interposed in the middle of the exhaust pipeline 21 and removes foreign matter from the air flowing through the exhaust pipeline 21 . The discharge line 21 passes through the aftercooler 16 between the drying filter 15 and the drying blower 17 . One end of the first supply pipe 22 is connected to the outlet of the drying blower 17 .

The adsorption unit 18 has an adsorption device 23 . The adsorber 23 has a configuration in which lids 25 are provided at both ends of a substantially cylindrical adsorption cylinder 24 . The adsorption cylinder 24 has a large number of air flow paths extending in its centerline direction. The inner surface of the air channel (the surface in contact with air) is made of an adsorbent (eg, zeolite) that adsorbs moisture. A first drying area, a second drying area, and a regeneration area are set in the area where the adsorption column 24 exists. , referred to as "first drying flow path"), an air flow path existing in the second drying area (hereinafter referred to as "second drying flow path"), and an air flow path existing in the regeneration area (hereinafter referred to as " (referred to as "regeneration channel"). A lid 25 at one end of the adsorber 23 is provided with a port 26A communicating with the first drying channel, a port 26B communicating with the second drying channel, and a port 26C communicating with the regeneration channel. The cover 25 at the other end of the adsorber 23 is provided with a port 27A communicating with the first drying channel, a port 27B communicating with the second drying channel, and a port 27C communicating with the regeneration channel. there is The suction unit 18 also has a rotation mechanism 28 that rotates the suction cylinder 24 around its center line. The rotation mechanism 28 includes a motor 29 as a drive source.

The adsorption unit 18 also includes a regeneration blower 31 and a regeneration heater 32 . A suction port of the regeneration blower 31 is open to the atmosphere through a regeneration filter 33 . One end of a regeneration line 34 is connected to the outlet of the regeneration blower 31 . The regeneration line 34 has an intermediate portion that passes through the aftercooler 16 and the regeneration heater 32 in that order, and the other end that is connected to the port 27C of the adsorber 23 . Thereby, the regeneration line 34 communicates with the regeneration channel of the adsorption column 24 . The other port 26C communicating with the regeneration channel is open to the atmosphere.

The other end of the first supply line 22 is connected to the port 26A of the adsorber 23 and communicates with the first drying line. On the other hand, one end of the second supply line 35 is connected to the port 27A communicating with the first drying flow path. The second supply pipe 35 passes through the drying heater 19 in the middle, penetrates the side wall of the drying hopper 11 , and has the other end inside the drying hopper 11 . Inside the drying hopper 11, the other end of the second supply pipe 35 is bent downward and extends into a conical shape that widens downward. A first return line 36 is branched and connected to the second supply line 35 between the adsorption section 18 and the drying heater 19 . The first return line 36 is connected to the port 27B of the adsorber 23 and communicates with the second drying channel of the adsorption cylinder 24 . One end of a second return line 37 is connected to the other port 26B that communicates with the second drying flow path. The other end of the second return line 37 is branched and connected to the discharge line 21 between the aftercooler 16 and the drying blower 17 .

When the drying blower 17 is driven, air is blown out from the outlet of the drying blower 17 to the first supply pipe 22 , and an air current directed toward the adsorption section 18 is generated in the first supply pipe 22 . The airflow flows from the port 26A of the adsorber 23 into the first drying channel of the adsorption column 24, passes through the first drying channel, and flows out from the port 26B of the adsorber 23 to the second supply line 35. . When the airflow passes through the first drying channel, the moisture contained in the airflow is absorbed by the adsorption column 24, and the airflow passing through the first drying channel becomes dry air with a low dew point. Part of the airflow that has flowed out to the second supply line 35 flows into the first return line 36, flows into the second drying line from the port 27B of the adsorber 23, and passes through the second drying line. , flows into the second return line 37 from port 26B of the adsorber. When the airflow passes through the second drying channel, the moisture contained in the airflow is adsorbed by the adsorption cylinder 24, and the airflow passing through the second drying channel has a lower dew point temperature, and the airflow passes through the second return channel. It joins the air flowing through the discharge line 21 from 37 .

The dry air flowing through the second supply pipe 35 is heated by the drying heater 19 to become heated dry gas and supplied into 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 granular material stored in the drying hopper 11 and escapes above the stored granular material. As a result, the dry gas deprives the granular material of moisture, thereby drying the granular material. The gas that has dehydrated the powder is discharged through the air discharge pipe 14 to the discharge pipe 21 and flows through the discharge pipe 21 toward the drying blower 17 .

Meanwhile, the regeneration blower 31 is driven. When the regeneration blower 31 is driven, outside air is sucked into the intake port of the regeneration blower 31 through the regeneration filter 33 . Then, the outside air is blown out from the outlet of the regeneration blower 31 to the regeneration line 34 , and an air current toward the adsorption section 18 is generated in the regeneration line 34 . The airflow (outside air) passes through the aftercooler 16 and the regeneration heater 32 in order, flows from the port 27C of the adsorber 23 into the regeneration channel of the adsorption column 24, passes through the regeneration channel, and reaches the port of the adsorber 23. 26C is released to the atmosphere. In the aftercooler 16, heat is exchanged between the outside air flowing through the regeneration line 34 and the air flowing through the discharge line 21, the temperature of the outside air flowing through the regeneration line 34 increases, and the temperature of the air flowing through the discharge line 21 decreases. . The outside air flowing through the regeneration line 34 is further heated by the regeneration heater 32 to become regeneration gas, and the regeneration gas passes through the regeneration channel of the adsorption column 24 . On the other hand, the portion of the adsorption column 24 that has adsorbed moisture from the air in the dry region moves to the regeneration region as the adsorption column 24 is rotated by the rotation mechanism 28 . As a result, the moisture adsorbed by the adsorption column 24 is desorbed from the adsorption column 24, and the adsorption column 24 is regenerated to a low humidity state. The temperature of the regeneration gas is set to, for example, 180 to 250° C. in order to desorb moisture from the adsorption column 24 .

The lower portion of the drying hopper 11 is formed in a conical shape that tapers downward, and a discharge port 41 is formed at the lower end thereof. The drying hopper 11 is provided with a gate shutter 42 for opening and closing the discharge port 41 . The granular material supplied from the loader hopper 12 can be stored in the dry hopper 11 with the gate shutter 42 closed and the discharge port 41 closed. A discharge branch pipeline 43 is connected to the discharge port 41 . The discharge branch pipeline 43 is interposed in the transport line 44 . When the gate shutter 42 is opened to open the discharge port 41 from the state in which the powder is stored in the drying hopper 11, the powder in the drying hopper 11 is discharged from the discharge port 41 into the discharge branch pipeline. 43 is discharged.

The transport line 44 includes a switching valve 45 , a first transport pipeline 46 and a second transport pipeline 47 .

The switching valve 45 has an input port 51 , a circulation output port 52 and an atmosphere opening port 53 . The switching valve 45 is provided with a valve body that individually opens and closes the circulation output port 52 and the atmosphere release port 53 . The switching valve 45 has a circulation position in which the atmosphere release port 53 is closed, the circulation output port 52 is opened, and the input port 51 and the circulation output port 52 are communicated in the valve box, depending on the positions of the valve bodies. It is switched to an open position in which the circulation output port 52 is closed, the atmosphere release port 53 is opened, and the input port 51 and the atmosphere release port 53 are communicated in the valve box.

One end of the first transport pipeline 46 is connected to the circulation output port 52 of the switching valve 45 . Above the molding machine 3, a destination hopper 54 is provided for storing the granular material to be fed into the molding machine 3, and the other end of the first transportation pipeline 46 is connected to the side wall of the destination hopper 54. and communicates with the destination hopper 54 .

One end of the second transport pipeline 47 is connected to the top wall of the destination hopper 54 and communicates with the interior of the destination hopper 54 . The other end of the second transport pipeline 47 is connected to the input port 51 of the switching valve 45 . A primary/secondary switching valve 55 , a dust collection cyclone 56 , a transport filter 57 and a transport blower 58 are installed in the second transport line 47 in this order from the transport destination hopper 54 side.

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 provided with a valve body that individually opens and closes the primary input port 61 and the secondary input port 62 . The primary/secondary switching valve 55 closes the secondary input port 62 and opens the primary input port 61 according to the positions of the valve bodies, thereby connecting the primary input port 61 and the output port 63 in the valve box. and a secondary transportation position in which the primary input port 61 is closed, the secondary input port 62 is opened, and the secondary input port 62 and the output port 63 are communicated in the valve box. can be switched to

The second transport pipeline 47 is further subdivided into a first pipeline section 71 , a second pipeline section 72 , a third pipeline section 73 , a fourth pipeline section 74 and a fifth pipeline section 75 . One end of the first pipeline portion 71 is connected to the upper wall of the destination hopper 54 as one end of the second transport pipeline 47 , and the other end of the first pipeline portion 71 is connected to two of the primary/secondary switching valves 55 . It is connected to the next input port 62 . One end of the second pipeline portion 72 is connected to the output port 63 of the primary/secondary switching valve 55 , and the other end of the second pipeline portion 72 is connected to the air introduction portion 76 of the dust collection cyclone 56 . . One end of the third pipeline portion 73 is connected to the intake portion 77 of the dust collection cyclone 56 , and the other end of the third pipeline portion 73 is connected to the inlet 78 of the transport filter 57 . One end of the fourth pipeline portion 74 is connected to the outlet 79 of the transport filter 57 and the other end of the fourth pipeline portion 74 is connected to the suction port of the transport blower 58 . One end of the fifth pipeline portion 75 is connected to the outlet of the transport blower 58 , and the other end of the fifth pipeline portion 75 is connected to the input port 51 of the switching valve 45 .

One end of a primary suction line 81 is connected to the upper wall of the loader hopper 12 , and the primary suction line 81 communicates with the inside of the loader 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 . One end of a granular material supply line 82 is connected to a side wall of the loader hopper 12 . The powder supply line 82 extends toward a raw material tank (not shown) storing powder, and the other end is connected to a suction pipe 83 arranged in the raw material tank.

When the powdery material is supplied from the raw material tank to the loader hopper 12, the switching valve 45 is set to the open position, and the primary/secondary switching valve 55 is set to the primary transportation position. When the transport blower 58 is driven, air is sucked into the suction port of the transport blower 58 from the fourth pipeline portion 74 and is blown out from the outlet of the transport blower 58 to the fifth pipeline portion 75 . The air blown out to the fifth pipe line portion 75 enters the valve box of the switching valve 45 from the input port 51 of the switching valve 45 and is released from the valve box to the atmosphere through the atmosphere release port 53 . As a result, a negative pressure is generated in the primary suction line 81, the second pipeline portion 72, the third pipeline portion 73, and the fourth pipeline portion 74, and the powder particles in the raw material tank are sucked by the negative pressure. The powder is sucked up by the pipe 83 and supplied into the loader hopper 12 from the suction pipe 83 through the granular material supply line 82 .

<Transportation/low dew point treatment>
FIG. 2 is a diagram showing the essential configuration of the manufacturing equipment 2 in a more simplified manner than in FIG.

The destination hopper 54 is provided with a dew point meter 91 for detecting the dew point temperature, which is a value corresponding to the amount of moisture contained in the air in the destination hopper 54 .

The granular material processing apparatus 1 also includes a control section 92 . A microcomputer (microcontroller unit) is provided in the control unit 92, and the microcomputer includes, for example, a CPU, a nonvolatile memory such as a flash memory, and a volatile memory such as a DRAM (Dynamic Random Access Memory). there is A detection signal from the dew point meter 91 is input to the control unit 92 . The control unit 92 controls the operation of each unit of the granular material processing apparatus 1 based on the dew point temperature detected by the dew point meter 91 and the like.

FIG. 3 is a flow chart showing the flow of processing performed after the drying process.

In the drying step, as described above, dry gas is supplied into the drying hopper 11 to dry the powder or granular material stored in the drying hopper 11 .

After the drying process, the controller 92 performs a closed circulation transportation process (step S1).

In the closed circulation transportation process, the switching valve 45 is set to the circulation position and the primary/secondary switching valve 55 is set to the secondary transportation position. Then the transport blower 58 is driven. When the transport blower 58 is driven, air is sucked from the fourth pipeline portion 74 into the suction port of the transport blower 58, and the fourth pipeline portion 74 becomes negative pressure. Due to the negative pressure, the air in the destination hopper 54 is sucked out to the first pipeline section 71, and the first pipeline section 71, the second pipeline section 72, the third pipeline section 73 and the fourth pipeline A current of air is generated in the portion 74 . On the other hand, the air blown out from the outlet of the transport blower 58 to the fifth pipeline portion 75 enters the valve box of the switching valve 45 from the input port 51 of the switching valve 45 and flows from the circulation output port 52 of the switching valve 45 to the fifth pipe section 75 . 1 transport line 46. As a result, a transportation airflow is generated by circulating air in the transportation line 44 consisting of the switching valve 45, the first transportation pipeline 46, and the second transportation pipeline 47. As shown in FIG. When the gate shutter 42 of the drying hopper 11 is opened and the discharge port 41 of the drying hopper 11 is opened, the powder in the drying hopper 11 is sucked out from the discharge port 41 to the transport line 44, and the powder is discharged. It is transported along the transportation line 44 (the first transportation pipeline 46 ) toward the destination hopper 54 on the transportation air current.

On the other hand, dry air is supplied into the drying hopper 11 even while the powder is being transported. 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 is 0° C. or less, preferably −20° C. or less.

Foreign matter such as dust contained in the transport airflow is collected as the transport airflow passes through dust collection cyclones 56 and 57 . In the dust-collecting cyclone 56, the air is sucked from the intake portion 77 of the dust-collecting cyclone 56 to the third pipe portion 73, so that the inside of the dust-collecting cyclone 56 becomes negative pressure. Due to the negative pressure, air (transportation airflow) is sucked into the dust collection cyclone 56 from the second pipe line portion 72 via the air introduction portion 76, and the air is swirled in the dust collection cyclone 56, causing centrifugal force. Air and the foreign matter are separated by the air and gravity, and the foreign matter is stored in a collection box connected to the lower end of the dust collection cyclone 56 .

By the closed circulation transportation process, the granular material in the drying hopper 11 is conveyed to the transportation destination hopper 54, and when the granular material in the drying hopper 11 disappears, the dew point reduction process is performed by the controller 92 (step S2).

In the dew point reduction process, the transport blower 58 is stopped. Then, the switching valve 45 is switched from the circulation position to the open position. As a result, the transport line 44 is opened to the atmosphere at the atmosphere opening port 53 of the switching valve 45 . The primary/secondary switching valve 55 remains in the secondary transfer position. At this time, the supply of dry air into the drying hopper 11 is continued, and the dew point temperature detected by the dew point meter 91 is 0 ° C. or less, preferably -20 ° C. or less. 18 and drying heater 19 are controlled.

Since dry air is supplied into the drying hopper 11 , the static pressure inside the drying hopper 11 is higher than the static pressure inside the destination hopper 54 . Due to the static pressure difference, dry air moves from inside the drying hopper 11 to the transport destination hopper 54 through the transport line 44 (first transport pipeline 46). As a result, the dew point inside the destination hopper 54 is lowered. At this time, a very small amount of dry air may be branched to the transport destination hopper 54 side.

The amount of dry air discharged by the opening is supplemented with outside air so that the pressure is adjusted on the drying hopper 11 side, and for example, the outside air can be taken in through the powder supply line 82 on the primary side. In addition, a supply port for supplementing air (outside air) may be provided in any of the dry air lines 13 , in which case it is preferable to provide the supply port upstream of the dehumidifying section 18 . Moreover, not only outside air but also pre-dehumidified dry air may be replenished.

<effect>
As described above, the inside of the transport destination hopper 54 can be made low in dew point. By lowering the dew point of the destination hopper 54 , it is possible to suppress moisture absorption of the granular material in the destination hopper 54 . By controlling the dew point temperature of the transport destination hopper 54 times to 0° C. or less, preferably −20° C. or less, it is possible to satisfactorily suppress moisture absorption of the granular material in the transport destination hopper 54 . As a result, it is possible to suppress unnecessary thermal decomposition and generation of gas when the powder is melt-molded by the molding machine 3 .

In addition, since the generation of the transportation airflow is stopped, the dry air is not actively sucked from the drying hopper 11 to the transportation line 44, and the dry air in the drying hopper 11 does not actively fluctuate. Therefore, the air volume in the drying hopper 11 can be stabilized, and the unstable temperature control in the drying hopper 11 can be suppressed.

Therefore, it is possible to reduce the dew point in the transport destination hopper 54 and prevent the air volume and temperature control in the drying hopper 11 from becoming unstable.

<Other embodiments>
FIG. 4 is a diagram showing the configuration of a granular material processing apparatus 101 according to another embodiment. In FIG. 4, parts corresponding to the parts shown in FIG. 2 are given the same reference numerals as those parts. Further, only the differences between the configuration shown in FIG. 4 and the configuration shown in FIG. 2 will be described below.

As shown in FIG. 4 , a nitrogen supply line 102 may be branched and connected to the dry air line 13 , and nitrogen gas generated by a nitrogen gas generator 103 may be introduced through the nitrogen supply line 102 . In the nitrogen gas generator 103, the air compressed by the air compressor 104 is supplied to the adsorption tank 105, and the adsorption tank 105 absorbs oxygen and moisture contained in the compressed air, thereby increasing the concentration of nitrogen. containing nitrogen gas is generated.

In this configuration, by introducing nitrogen gas into the dry air, the inside of the drying hopper 11 becomes a nitrogen gas atmosphere, and the granules can be dried in the inert gas atmosphere. As a result, it is possible to suppress the oxidizing gas from being contained in the granules, and to suppress the occurrence of problems such as yellowing of plastic products due to the melting and molding of the granules containing the oxidizing gas.

FIG. 5 is a diagram showing the configuration of a granular material processing apparatus 111 according to still another embodiment. In FIG. 5 as well, parts corresponding to those shown in FIG. 2 are denoted by the same reference numerals as those parts, and descriptions of the parts denoted by the same reference numerals are omitted.

In the configuration shown in FIG. 2, the switching valve 45 is interposed between the first transport pipeline 46 and the second transport pipeline 47, and when the switching valve 45 is in the circulation position, the second transport pipeline By switching the line 47 (fifth pipeline section 75) to the first transport pipeline 46 via the switching valve 45, the transport line 44 becomes a closed loop transport line.

As shown in FIG. 5, the switching valve 45 is omitted, and an open/close valve 112 is provided at the downstream end of the second transport pipe 47 in the direction in which the transport airflow flows (transport direction). In the process of transporting the granular material from the drying hopper 11 to the destination hopper 54 after the drying process and the process of reducing the dew point inside the destination hopper 54 while the valve 112 is closed, the on-off valve 112 may be opened.

The configuration of the granular material processing apparatus 111 can also provide the same operational effects as the configuration of the granular material processing apparatus 1 .

<Modification>
Although several embodiments of the present invention have been described above, the present invention can also be implemented in other forms.

For example, in the configuration shown in FIG. 2, the operation of the granular material processing apparatus 1 is controlled based on the dew point measured using the dew point meter 91, but the dew point meter 91 may be omitted. In that case, for example, the time for switching the switching valve 41 to the open position may be determined in advance within a range in which the dew point can be lowered, and only the time may be controlled.

A method of heating the destination hopper 54 may also be used. Even if there is no heating mechanism, if the dew point can be lowered, the equipment cost will be low, which is advantageous. By using them together, the effect of lowering the dew point can be enhanced.

In addition, in the configuration shown in FIG. 5 , a check valve that prevents outside air from being taken into the second transport pipeline 47 from the outside may be provided in place of the on-off valve 112 .

In addition, the on-off valve 112 or a check valve in place thereof may be installed upstream of the transport blower 58 as long as it is downstream of the transport destination hopper 54 in the direction in which the transport airflow flows.

The transport blower 58 may be interposed not only in the second transport pipeline 47 but also in the first transport pipeline 46 .

The manufacturing facility 2 may also include a plurality of molding machines 3, as indicated by the dashed lines in FIG. For example, in a configuration in which two molding machines 3 are included in the manufacturing facility 2 , the primary/secondary switching valve 55 is additionally provided with a secondary input port 64 to transport the added molding machine 3 to the destination hopper 54 . A branch pipe 65 branched from the first transport pipe line 46 is connected to the side wall of the , one end of a sixth pipe line portion 66 is connected to the upper wall of the destination hopper 54, and the sixth pipe line portion 66 is connected to the secondary input port 64 . When the granular materials are transported to the added molding machine 3, the primary/secondary switching valve 55 closes the primary input port 61 and the secondary input port 62, and the secondary input port 64 is closed. and the output port.

In addition, various design changes can be made to the above configuration within the scope of the matters described in the claims.

1, 101, 111: Granular material processing device 11: Drying hopper (storage unit)
13: Drying Air Line 17: Drying Blower (Drying Airflow Generating Part)
18: Adsorption part (dehumidification part)
19: Drying heater (heating unit)
24: Adsorption cylinder 28: Rotating mechanism (rotating part)
31: Regeneration blower (regeneration air supply unit)
32: Regeneration heater (regeneration air supply unit)
34: Regeneration line (regeneration air supply unit)
44: Transport line 45: Switching valve 46: First transport pipeline 47: Second transport pipeline 58: Transport blower (transport airflow generator)
91: Dew point meter 92: Control unit

Claims (9)

a storage unit that stores the granular material inside;
a dry air supply unit that supplies dehumidified and heated dry air into the storage unit;
a transport line that communicates with the interior of the storage unit and extends downstream of the transportation destination in the transportation direction from the storage unit to the transportation destination via the transportation destination of the powder or granular material from the storage unit;
a transport airflow generator for generating a transport airflow in the transport direction in the transport line;
After performing a transportation process of generating the transportation airflow by the transportation airflow generation unit and transporting the granular material accommodated in the storage unit to the transportation destination, the transportation line is higher than the transportation destination. A dew point lowering process for lowering the dew point of the transportation destination by creating a state in which the downstream side in the transportation direction is open to the atmosphere and generation of the transportation airflow by the transportation airflow generation unit is stopped. a control unit that performs The dry air supply unit is
a dry airline communicating with the inside of the housing;
a drying airflow generating section that generates an airflow in the drying air line in a direction toward the accommodation section;
a dehumidification unit that dehumidifies the air flowing through the dry air line;
2. The granular material processing apparatus according to claim 1, further comprising a heating section for heating air flowing through said dry air line. A drying area and a regeneration area are set in the dehumidifying section,
The drying airline passes through the drying area,
The dehumidifying section is
an adsorption cylinder formed in a cylindrical shape and arranged across the drying area and the regeneration area;
a rotating part that rotates the adsorption cylinder about its center line;
3. The granular material processing apparatus according to claim 2, further comprising a regeneration air supply unit that supplies heated regeneration air to the regeneration region. The transportation line is
a first transport pipeline whose downstream end in the transport direction is connected to the transport destination;
a second transport pipeline whose upstream end in the transport direction is connected to the transport destination;
The upstream end of the first transport pipeline in the transport direction and the downstream end of the second transport pipeline in the transport direction are connected, and the upstream end of the first transport pipeline and the second transport pipeline are connected to each other. a switching valve that is switched between a circulation position that communicates with the downstream end and an open position that closes the upstream end of the first transport pipeline and opens the downstream end of the second transport pipeline to the atmosphere; The powder and granular material processing apparatus according to any one of claims 1 to 3, comprising: The granular material processing apparatus according to any one of claims 1 to 4, further comprising a dew point meter that detects the dew point temperature at the transportation destination. The granular material processing apparatus according to any one of claims 1 to 5, wherein the control unit controls the dry air supply unit so that the dew point temperature at the transportation destination is 0°C or less. The granular material processing apparatus according to any one of claims 1 to 6, further comprising an inert gas introducing section that introduces an inert gas into the accommodating section. A plurality of destinations are set,
The granular material processing apparatus according to any one of claims 1 to 7, further comprising a transportation destination switching unit that switches the transportation destination through which the transportation line passes among the plurality of transportation destinations. a storage unit that stores a powder or granular material therein, communicating with the inside of the storage unit, and transporting the powder or granular material from the storage unit to the transportation destination rather than the transportation destination via the transportation destination of the powder or granular material from the storage unit A transport line extending to the downstream side of the direction, and a method of processing granules in an apparatus comprising:
a drying step of supplying dehumidified and heated dry air into the accommodating portion accommodating the granular material to dry the granular material;
After the drying step, a transporting step of generating a transporting airflow in the transporting direction in the transporting line to transport the granular material contained in the container to the transporting destination;
After the transport step, the transport line is opened to the atmosphere downstream of the transport destination in the transport direction, and generation of the transport airflow is stopped, thereby reducing the transport destination. and a low dew point step of reducing the dew point.

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