JP2010260185A - Dryer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dryer which can improve the accuracy of the supply of powder etc., as materials and is superior in cost performance and working properties. <P>SOLUTION: The dryer 1 is equipped with a dryer 2 having a drying hopper 5 and a blower unit 6, a loader hopper 3 which is arranged vertically above the dryer 2 and has material supply opening 19 and an opening/closing valve 20 which opens the material supply opening 19, a suction type blower 4, a branch suction line 22 connected to the loader hopper 3, a branch vacuum line 23 connected to the drying hopper 5, a switching operation valve 21 connected to the branch suction line 22 and the branch vacuum line 23, and a suction-vacuum line 24 connected to the switching operation valve 21 and the suction type blower 4. In the dryer 1, the inside of the drying hopper 5 is decompressed, as the need arises, by the switching operation of the switching operation valve 21. Since the inside of the loader hopper 3 can be sucked, the accuracy of material supply can be improved, so that the materials can be dried surely in good working properties. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a drying apparatus, and more particularly, to a drying apparatus that dries a granular material as a material.

Conventionally, in molding processing of resin pellets or the like, a drying step for reducing the water content of the resin pellets to a certain level of water content is included as one of the processing steps.
As a drying apparatus used in such a drying process, for example, a dehumidifying apparatus and a dry air supply duct which are dry air introduction means for introducing dry air, and an exhaust duct which is an exhaust section for discharging the used dry air Has been proposed (see, for example, Patent Document 1).

  This drying device is provided in a raw material charging unit of an extruder or an injection molding machine, and the raw material charging unit includes a raw material supply pipe for conveying the raw material by air, a dust collector for separating the conveying air and the raw material, and conveying air. Exhaust piping connected to the blower to be sucked in, a rotary valve that drops the raw material separated by the dust collector in a state where ventilation is shut off, and a chute that connects the rotary valve and the raw material hopper of the extruder or injection molding machine The dry air is introduced into the chute.

  In such an apparatus, the raw material is conveyed from the raw material supply pipe by the conveying air, separated from the conveying air by the dust collector, and supplied from the rotary valve into the chute. Then, the raw material falls into the raw material hopper while being dried by the dry air supplied into the chute from the dehumidifier and the dry air supply duct. In addition, the raw material dropped into the raw material hopper is further dried by the dry air.

In such an apparatus, the transported raw material is temporarily stored in a dust collector and then supplied to the chute as necessary.
As a dust collector capable of temporarily storing such raw materials, for example, in a storage tank of granular material transported by gas, a granular material discharge port is provided at the lower part of the tank body, and the granular material discharge port Has proposed a granule storage tank in which an on-off valve is provided so as to move vertically in a position where the granule outlet is closed or substantially closed by a swing arm (for example, Patent Document 2). reference.).

  In such a granular material storage tank, when the granular material as a dry material is sucked together with the carrier air, the on-off valve provided at the lower part of the granular material discharge port is sucked upward by the suction force, and the powder While closing a granule discharge port, a tank main body becomes a negative pressure and a granular material is stored in it. Then, after a predetermined amount of powder has been stored in the tank body, or after a predetermined time has elapsed since the start of storage, if the suction is stopped, the negative pressure in the tank body is eliminated, so the tank body stores The on-off valve is opened by the weight of the granulated material and the weight of the on-off valve, and the granular material is discharged from the granular material discharge port.

JP 2002-160218 A JP-A-9-263333

  However, in the drying apparatus described in Patent Document 1, when the storage tank described in Patent Document 2 is used, the pressure in the raw material hopper in the drying apparatus described in Patent Document 1 is caused by the dry air supplied into the raw material hopper. Since the pressure is higher than the atmospheric pressure, the opening / closing valve of the granular material discharge port is pressed toward the granular material discharge port by the pressure in the raw material hopper. As a result, in such a drying apparatus, the powder discharge port cannot be opened due to the weight of the powder stored in the tank body and the weight of the on-off valve, and the powder can be discharged. Since this may not be possible, the material supply accuracy may be reduced.

  On the other hand, in order to solve such a problem, for example, it is proposed that a filter capable of releasing the pressure in the raw material hopper is attached to the upper portion of the raw material hopper to relieve the pressurized state in the raw material hopper. However, in such a method, since the raw material supplied into the raw material hopper may clog the filter, there is a problem that regular maintenance is required and workability is poor.

In addition, for example, a method of using an automatic damper such as an air cylinder for the opening / closing valve of the granular material discharge port is proposed, but since the automatic damper is expensive, such a method is costly and economical. There is a problem of being inferior.
An object of the present invention is to provide a drying apparatus that can improve the supply accuracy of a granular material as a material, and is excellent in cost and workability.

  In order to achieve the above object, a drying apparatus according to the present invention includes a drying hopper to which a material is supplied, a dryer provided with a blowing means for supplying a drying medium to the drying hopper, and a vertical direction of the dryer. A material supply port disposed above and communicating with the drying hopper, an open / close valve that opens the material supply port due to its own weight and the weight of the material, a temporary storage tank for storing the material, and the inside of the drying hopper is decompressed And a decompression means.

  According to such a drying apparatus, even when the inside of the drying hopper is pressurized to a pressure higher than the atmospheric pressure by the air blowing means, the pressure inside the drying hopper can be reduced by the pressure reducing means to control the pressure in the drying hopper. it can. Therefore, the material supply port provided in the temporary storage tank can be opened by the dead weight of the on-off valve and the weight of the material, the material supply accuracy can be improved, and the material can be reliably dried. Furthermore, since the maintenance load can be reduced, the workability is excellent.

In the drying apparatus of the present invention, it is preferable that the temporary storage tank is a loader hopper, and includes suction means for sucking the loader hopper to pneumatically transport the material.
According to such a drying apparatus, since the material can be pneumatically transported, the material can be supplied to the drying hopper with high accuracy, and further, the inside of the loader hopper is sucked by the suction means. Adhesion with the supply port can be improved, and the material supply port can be closed more reliably.

In the drying apparatus of the present invention, it is preferable that the suction means also serves as the decompression means.
According to such a drying device, the inside of the loader hopper can be sucked by a single suction means, while the inside of the drying hopper can be depressurized. Therefore, compared to the case where the suction means and the pressure reducing means are provided separately, Cost reduction can be achieved.

  Further, the drying apparatus of the present invention is connected to the loader hopper, a branch suction line for sucking the loader hopper, a branch decompression line connected to the drying hopper and decompressing the drying hopper, A switching means connected to the branch suction line and the branch decompression line, for switching between decompression of the drying hopper and suction of the loader hopper, and a suction-decompression line connected to the switching means and the suction means; It is suitable to provide.

According to such a drying apparatus, the suction in the loader hopper and the decompression in the drying hopper can be switched by the switching means, so that the loader hopper or the drying hopper can be selectively suctioned or decompressed. The workability can be improved.
In the drying apparatus of the present invention, it is preferable that a filter is provided between the switching unit and the suction unit in the suction-decompression line.

According to such a drying apparatus, even when the material and dust are mixed into either the branch suction line or the branch pressure reduction line, the mixed material or dust can be efficiently collected with a single filter. it can.
In the drying apparatus of the present invention, the drying hopper has a mounting portion that protrudes upward in the vertical direction, the material supply port is arranged in the mounting portion, and the branch pressure reducing line is connected to the mounting portion. It is preferred that

  According to such a drying apparatus, even when the inside of the drying hopper is pressurized to a pressure higher than the atmospheric pressure by the air blowing means, the material supply port and the connecting portion of the branch pressure reducing line to the drying hopper are attached to the mounting portion. Since it is surrounded, the inside of the drying hopper can be decompressed by the decompression means, and only the pressure around the material supply port surrounded by the mounting portion can be controlled. Therefore, the material supply port provided in the temporary storage tank can be opened by the own weight of the on-off valve and the weight of the material, and the material supply accuracy can be further improved.

Further, the drying apparatus of the present invention includes a pressure detection sensor for detecting the pressure in the drying hopper, and a control means for controlling the switching means, and the control means outputs a signal from the pressure detection sensor. It is preferable to control the switching means based on this.
According to such a drying apparatus, the inside of the drying hopper can be decompressed only when necessary, and the material can be supplied with high accuracy.

  In the drying apparatus of the present invention, the control means has a transportation-drying switching program, and the transportation-drying switching program includes a blowing step of supplying a drying medium to the drying hopper by the blowing means. The switching means closes the branch decompression line, and the suction line opening step for opening the branch suction line, and the suction means sucks the loader hopper and closes the material supply port with the on-off valve. And a material transport step for transporting the material to the loader hopper, a pressure detection step for detecting the pressure in the drying hopper by the pressure detection sensor after a lapse of a predetermined time from the start of transport of the material, and a pressure detection step. When the pressure in the drying hopper is equal to or higher than a predetermined pressure, In the depressurization step of closing the branch suction line by the replacement means and stopping the transportation of the material to the loader hopper, opening the branch depressurization line and depressurizing the inside of the drying hopper, and the pressure detection step When the detected pressure in the drying hopper is less than a predetermined pressure, the suction stop step for stopping suction, and after the pressure reducing step or the suction stop step, the weight of the on-off valve and the weight of the material It is preferable to include a drying step of opening a material supply port, supplying the material stored in the loader hopper to the drying hopper, and drying the material with a drying medium.

  According to such a drying apparatus, the control means can uniformly switch between the decompression of the drying hopper and the suction of the loader hopper. As a result, the material supply accuracy can be improved, and the material can be reliably dried with good workability.

  According to the drying apparatus of the present invention, it is possible to improve the supply accuracy of a granular material as a material. Moreover, the drying apparatus of the present invention is excellent in cost and workability.

It is the schematic which shows one Embodiment of the drying apparatus of this invention. The flowchart of one Embodiment of the drying process by the drying apparatus shown in FIG. 1 is shown. It is the schematic which shows other embodiment of the drying apparatus of this invention.

FIG. 1 is a schematic view showing an embodiment of the drying apparatus of the present invention.
In FIG. 1, a drying device 1 is a device used for drying materials (for example, a granular material (resin pellet) containing moisture), and includes a dryer 2 and a loader hopper 3 as a temporary storage tank. And a suction-type blower 4 as suction means that also serves as decompression means.
The dryer 2 is a device for bringing a material into contact with a drying medium such as hot air and drying the material. The drying hopper 5 to which the material is supplied and a blowing unit for supplying the drying medium to the drying hopper 5 are used. The ventilation unit 6 is provided.

The drying hopper 5 includes a drying container portion 7 and a drying upper wall portion 8.
The drying container portion 7 is a container for receiving and drying a material supplied from a loader hopper 3 (described later), and an upper portion thereof is formed in a substantially cylindrical shape, and the side wall of the blower unit 6 is formed on the side wall thereof. A drying medium supply pipe 11 (described later) is connected so as to face the drying container section 7.

Further, the drying container portion 7 is formed in a substantially conical cylinder shape whose lower portion has a lower inner diameter as it goes from the upper side to the lower side, and at the lower end portion thereof, there is a material discharge port 9 for discharging the material, Is formed. Although not shown, other processing devices (for example, a molding machine, a mixer, etc.) are connected to the material discharge port 9 as necessary.
The drying upper wall portion 8 is an upper lid that closes the upper portion of the drying hopper 5 and is formed integrally with the drying container portion 7.

A lower end portion of a loader hopper 3 (described later) is connected to the drying upper wall portion 8 so as to pass therethrough, and a drying hopper 5 and a loader hopper are formed by a material supply port 19 (described later) formed in the loader hopper 3 (described later). 3 (described later).
Further, a cyclone 29 for removing dust generated in the drying hopper 5 is connected to the drying upper wall portion 8. Although mentioned later in detail, the cyclone 29 is open | released by air | atmosphere, and, thereby, the pressure in the drying hopper 5 is substantially released.

Further, a branch pressure reducing line 23 (described later) for decompressing the inside of the drying hopper 5 is connected to the drying hopper 5 on the radially outer side of the material supply port 19 (described later), and the pressure in the drying hopper 5 is detected. For this purpose, a pressure detection sensor 25 (described later) is provided.
The blower unit 6 is a device for supplying a drying medium for drying a material into the drying hopper 5, and includes a drying medium generator 10 and a drying medium supply pipe connected to the drying medium generator 10. 11.

The drying medium generator 10 is an apparatus that generates a drying medium, and although not shown, for example, a heating unit (for example, a heater) for heating air and a blowing type for blowing heated air. Power source (for example, a blower).
The drying medium supply pipe 11 is a pipe for supplying the drying medium generated by the drying medium generator 10 into the drying hopper 5 and penetrates the side wall of the drying container portion 7 of the drying hopper 5. The other end is connected to the drying medium generator 10 and the other end is accommodated in the drying hopper 5.

Further, the other end portion of the drying medium supply pipe 11 is bent downward in the vertical direction in the drying hopper 5.
And the front-end | tip part of the dry-medium supply pipe | tube 11 is formed in the substantially conical cylinder shape which becomes large diameter as it goes below from the upper direction, and the dry-medium blower outlet 12 opened toward the downward direction is formed in the front-end | tip edge. Is formed.

The loader hopper 3 is a device for transporting the material pneumatically and temporarily storing the material before supplying it to the dryer 2. The loader hopper 3 is disposed vertically above the dryer 2 and communicates with the drying hopper 5. is doing.
The loader hopper 3 includes a storage container portion 13 and a storage upper wall portion 14.
The storage container portion 13 is a container for receiving the material that has been pneumatically transported, and is formed integrally with the upper cylindrical portion 15 formed in a substantially cylindrical shape and the upper cylindrical portion 15, and vertically below. A conical cylinder portion 16 formed in a substantially conical cylinder shape having a smaller diameter toward the bottom, and a lower cylindrical portion formed integrally with the conical cylinder portion 16 and having a smaller diameter than the upper cylinder portion 15. 17.

A material transport line 18 communicating with a material tank (not shown) for storing material is connected to the side wall of the upper cylindrical portion 15 of the storage container portion 13.
Further, the storage container portion 13 is connected to the drying hopper 5 through the drying upper wall portion 8 so that the lower cylindrical portion 17 is accommodated in the drying hopper 5. A material supply port 19 (described later) is formed.

The storage upper wall portion 14 is an upper lid that closes the upper portion of the loader hopper 3, and is formed integrally with the storage container portion 13.
Further, a branch suction line 22 (described later) for sucking the loader hopper 3 is connected to the storage upper wall portion 14, and between the material transport line 18 and the branch suction line 22 (described later), A suction line filter 30 such as a punching filter is interposed.

The suction line filter 30 is provided on the lower side of the storage upper wall portion 14 so as to cover a connection portion between the storage upper wall portion 14 and a branch suction line 22 (described later) connected to the storage upper wall portion 14. Has been placed. The suction line filter 30 prevents the material transported from the material transport line 18 into the loader hopper 3 from being mixed into the branch suction line 22 (described later).
The loader hopper 3 includes an on-off valve 20 that opens the material supply port 19 by its own weight and the weight of the material.

The material supply port 19 is an opening that opens downward at the lower end of the loader hopper 3, and allows the drying hopper 5 and the loader hopper 3 to communicate with each other.
Such a material supply port 19 is, for example, an opening having a substantially elliptical shape as viewed from the bottom, which is opened by cutting the lower cylindrical portion 17 of the loader hopper 3 into an inclined shape intersecting the horizontal direction and the vertical direction. As formed.

The on-off valve 20 is a valve for opening and closing the material supply port 19 of the loader hopper 3, and is provided in the vicinity of the material supply port 19 outside the storage container portion 13.
Such an on-off valve 20 is formed, for example, by bending a metal plate that is symmetrically formed at a predetermined angle along the symmetry line.
More specifically, the on-off valve 20 is formed by, for example, a substantially 8-shaped metal plate in plan view in which two substantially elliptical metal plates slightly larger than the material supply port 19 are connected so as to be symmetrical. The manufactured metal plate is formed by being bent into a substantially inverted V shape when viewed from the front at the connecting portion of the two metal plates so that the substantially elliptical portions intersect at a predetermined angle.

Such an on-off valve 20 can swing in the left-right direction to be symmetrical so that the left and right being symmetrical are balanced by suspending the bent portion on the outer peripheral surface of the storage container portion 13. Is provided.
In the drying apparatus 1, the on-off valve 20 is described later in detail. When the internal pressure of the drying hopper 5 is higher than the internal pressure of the loader hopper 3 (for example, the internal pressure of the drying hopper 5 is equal to or higher than the atmospheric pressure, the loader hopper When the internal pressure of the loader hopper 3 is less than the atmospheric pressure), the material supply port 19 is sucked by the internal pressure of the loader hopper 3 toward the material supply port 19 side of the loader hopper 3 (see the broken line in FIG. 1). . On the other hand, when the internal pressure of the dry hopper 5 is equal to or lower than the internal pressure of the loader hopper 3 (for example, when the internal pressure of the loader hopper 3 and the internal pressure of the dry hopper 5 are both atmospheric pressure) The material supply port 19 can be opened because it swings due to its own weight and the weight of the material stored in the loader hopper 3 and is separated from the material supply port 19.

The suction-type blower 4 is a suction-type pneumatic power source, and serves as both a suction means for sucking the loader hopper 3 to pneumatically transport the material and a decompression means for sucking and decompressing the inside of the dry hopper 5. ing.
The drying device 1 is provided with a switching operation valve 21 as a switching means. By the switching operation valve 21, suction in the loader hopper 3 by the suction type blower 4 and decompression in the drying hopper 5 are performed. Has been switched.

More specifically, the drying apparatus 1 includes a switching operation valve 21, a branch suction line 22, a branch decompression line 23, and a suction-decompression line 24 connected to the switching operation valve 21.
The switching operation valve 21 is a valve mechanism including a three-way valve for switching between depressurization of the drying hopper 5 by the suction type blower 4 and suction of the loader hopper 3, and is connected to the branch suction line 22 and the branch pressure reduction line 23. And connected to the suction-decompression line 24.

The branch suction line 22 is a pipe for sucking the loader hopper 3. One end of the branch suction line 22 is connected to the storage upper wall portion 14 of the loader hopper 3 and the other end is connected to the switching operation valve 21.
The branch decompression line 23 is a pipe for decompressing the inside of the drying hopper 5, and one end thereof is connected to the drying upper wall portion 8 of the drying hopper 5 and the other end is connected to the switching operation valve 21. .

The suction-decompression line 24 is a relay pipe for sucking the loader hopper 3 or depressurizing the drying hopper 5, one end of which is connected to the switching operation valve 21 and the other end of the suction blower 4. It is connected to the.
The switching operation valve 21 connected in this way can close the branch suction line 22 and open the branch pressure reduction line 23, while opening the branch suction line 22 and closing the branch pressure reduction line 23. Can do.

When the switching operation valve 21 opens the branch suction line 22 and closes the branch decompression line 23, the suction type blower 4 passes through the suction-decompression line 24, the switching operation valve 21 and the branch suction line 22. Then, it communicates with the loader hopper 3.
When the suction type blower 4 is driven in this state, the suction type blower 4 sucks the loader hopper 3 without reducing the pressure inside the drying hopper 5.

  When the loader hopper 3 is sucked by the suction blower 4, the on-off valve 20 provided in the material supply port 19 is sucked up by the suction force of the suction blower 4 and is swung toward the material supply port 19 side. The material supply port 19 is closed. And since the inside of the loader hopper 3 becomes a negative pressure by the suction of the suction type blower 4, the material is pneumatically transported from the material tank (not shown) into the loader hopper 3 through the material transport line 18.

According to such a drying apparatus 1, since the material can be pneumatically transported, the material can be accurately supplied to the drying hopper 5, and further, the inside of the loader hopper 3 is sucked by the suction type blower 4. The adhesion between the on-off valve 20 and the material supply port 19 can be improved, and the material supply port 19 can be closed more reliably.
Further, when the branch suction line 22 is closed and the branch pressure reduction line 23 is opened by the switching operation valve 21, the suction type blower 4 has the suction-pressure reduction line 24, the switching operation valve 21 and the branch pressure reduction line 23. To the drying hopper 5.

When the suction type blower 4 is driven in this state, the suction type blower 4 sucks the inside of the dry hopper 5 without sucking the inside of the loader hopper 3. Thereby, the inside of the drying hopper 5 is depressurized.
Usually, the inside of the drying hopper 5 is in a pressurized state by supplying a drying medium by the blower unit 6. Therefore, in this state, the material supply port 19 may not be opened due to the weight of the on-off valve 20 and the weight of the material stored in the loader hopper 3.

However, in this drying apparatus 1, the inside of the drying hopper 5 can be decompressed by the suction blower 4.
Therefore, according to such a drying apparatus 1, even when the inside of the drying hopper 5 is pressurized to an atmospheric pressure or higher by the blower unit 6, the inside of the drying hopper 5 is decompressed by the suction blower 4, and the drying hopper 5 can be controlled (reduced pressure state). Therefore, the material supply port 19 provided in the loader hopper 3 can be opened by the weight of the on-off valve 20 and the weight of the material stored in the loader hopper 3, and the material supply accuracy can be improved. Since the material can be reliably dried, and further, the maintenance load can be reduced, the workability is excellent.

In this drying apparatus 1, one suction blower 4 communicates with the loader hopper 3 and sucks the loader hopper 3 to pneumatically transport the material, while communicating with the drying hopper 5 and passes through the drying hopper 5. The pressure is reduced by suction.
Therefore, according to such a drying apparatus 1, cost reduction can be achieved compared with the case where a suction means and a pressure reduction means are provided separately.

Furthermore, according to such a drying apparatus 1, the suction in the loader hopper 3 and the decompression in the drying hopper 5 can be switched by the switching operation valve 21, so the loader hopper 3 or the drying hopper 5 is selected. Therefore, it is possible to perform suction or decompression, and workability can be improved.
In the drying apparatus 1, a filter 27 is provided between the switching operation valve 21 and the suction type blower 4 in the suction-decompression line 24.

According to such a drying apparatus 1, even when material or dust is mixed into either the branch suction line 22 or the branch pressure reduction line 23, the mixed material or dust is efficiently captured by the single filter 27. Can be collected.
The drying device 1 further includes a pressure detection sensor 25 that detects the pressure in the drying hopper 5 and a control device 26 that serves as a control unit for controlling the switching operation valve 21.

The pressure detection sensor 25 is a sensor for detecting the pressure in the drying hopper 5 and is provided in the drying hopper 5, more specifically, in the vicinity of the material supply port 19.
The control device 26 is a device for controlling the switching operation valve 21 based on a signal from the pressure detection sensor 25, and is connected to the switching operation valve 21 and the pressure detection sensor 25.
Such a control device 26 has a transportation-drying switching program. For example, when the pressure in the drying hopper 5 is higher than a predetermined set value, the branch suction line 22 is closed and the branch decompression line 23 is closed. Is opened and the pressure in the drying hopper 5 is reduced, while when the pressure in the drying hopper 5 is lower than a predetermined set value, the branch suction line 22 is opened and the branch pressure reduction line 23 is closed to load the loader hopper. The switching operation valve 21 can be operated in accordance with an arbitrary setting such as suctioning in the interior of 3.

FIG. 2 is a flowchart of an embodiment of a drying process by the drying apparatus 1.
Here, with reference to FIG. 2, the process in the drying apparatus 1 by a transport-drying switching program is demonstrated.
In this drying apparatus 1, first, the blowing unit 6 is driven to supply the drying medium into the drying hopper 5 (air blowing step: air blowing start).

Next, in this method, the branch decompression line 23 is closed and the branch suction line 22 is opened by the switching operation valve 21 (suction line opening step: S1).
Thereby, the suction type blower 4 communicates with the loader hopper 3 through the suction-decompression line 24, the switching operation valve 21 and the branch suction line 22.
Next, in this method, the loader hopper 3 is sucked by the suction type blower 4, the material supply port 19 is closed by the on-off valve 20, and the material is transported to the loader hopper 3 (material transporting step: S2).

That is, when the inside of the loader hopper 3 is sucked by the suction type blower 4, the opening / closing valve 20 is swung toward the material supply port 19 by the suction force, and the material supply port 19 is thereby closed. As a result, the loader hopper 3 has a negative pressure, and the material is transported from the material tank (not shown) into the loader hopper 3 by the material transport line 18.
In this state, the drying medium is supplied into the drying hopper 5 and the material supply port 19 is closed. At this time, the drying medium supplied from the blower unit 6 is released to the atmosphere via a cyclone 29 communicating with the atmosphere.

  However, for example, by opening the drying hopper 5 and attaching a filter to the opening, the drying hopper 5 is directly communicated with the atmosphere, and the supplied drying medium is released to the atmosphere (that is, inside the drying hopper 5). In the drying apparatus 1, the inside of the drying hopper 5 cannot be sufficiently depressurized because of the resistance of the cyclone 29.

That is, in such a drying apparatus 1, the inside of the drying hopper 5 cannot be made into atmospheric pressure, and the inside of the drying hopper 5 is brought into a pressurized state.
Next, in this method, the pressure in the drying hopper 5 is detected by the pressure detection sensor 25 at the end of transportation after a predetermined time (transportation time) has elapsed (S3) from the start of transportation of the material (pressure detection step: S4).

And based on the pressure in the drying hopper 5 detected by a pressure detection step, the switching operation valve 21 is operated by the control apparatus 26 (S5).
More specifically, when the detected pressure in the dry hopper 5 is equal to or higher than a predetermined pressure, a pressure reducing step is performed, and the pressure in the dry hopper 5 is less than the predetermined pressure. The suction stop step is performed.

  That is, in the pressure reducing step, when the pressure in the drying hopper 5 detected in the pressure detecting step is equal to or higher than a predetermined pressure (for example, 1 KPa) (S5: YES), the suction by the suction type blower 4 is continued. Then, the branch operation suction line 22 is closed by the switching operation valve 21 to stop the transport of the material to the loader hopper 3, and the branch pressure reducing line 23 is opened to decompress the inside of the drying hopper 5 (S6).

The pressure in the drying hopper 5 is controlled by the depressurization step. For example, the internal pressure of the drying hopper 5 is set to be equal to or lower than the internal pressure of the loader hopper 3 (for example, the internal pressure of the drying hopper 5 and the internal pressure of the loader hopper 3 are both atmospheric pressure). be able to.
On the other hand, in the suction stop step, when the pressure in the drying hopper 5 detected in the pressure detection step is less than a predetermined pressure (for example, 1 KPa) (S5: NO), the switching operation valve 21 is not operated (S5: NO). That is, the suction by the suction type blower 4 is stopped while the branch suction line 22 is opened and the branch pressure reduction line 23 is closed (S7).

Next, in this method, after the pressure reducing step or the suction stop step, the material supply port 19 is opened by the weight of the on-off valve and the weight of the material stored in the loader hopper 3, and the material stored in the loader hopper 3 is removed from the drying hopper 5. And the material is dried with a drying medium (drying step: S8).
That is, after the pressure reduction step or the suction stop step, there is no suction, and the internal pressure of the drying hopper 5 is equal to or lower than the internal pressure of the loader hopper 3, so that the on-off valve 20 has its own weight and the material stored in the loader hopper 3. And the material supply port 19 is opened.

As a result, the material pneumatically transported into the loader hopper 3 is supplied from the material supply port 19 into the drying hopper 5, contacts the drying medium (the drying medium supplied into the drying hopper 5), and is dried.
Then, after a predetermined time has elapsed from the pressure reducing step (S6) or the suction stop step (S7), a known level meter (in FIG. (S9).

When the material in the drying hopper 5 has reached a predetermined amount (S9: YES), the driving of the suction blower 4 and the operation of the switching operation valve 21 are ended (processing is ended), while the blower unit 6 performs the operation. By continuing the blowing, a predetermined amount of material supplied into the drying hopper 5 is continuously dried.
When the material in the dry hopper 5 has not reached the predetermined amount (S9: NO), the above program is repeated to supply (add) the material to the dry hopper 5 while drying the material.

More specifically, if the material in the drying hopper 5 has not reached a predetermined amount after the above depressurization step (S6) is adopted, the switching operation valve 21 is operated and the branch suction line 22 is opened. At the same time, the branch decompression line 23 is closed (S10).
If the material in the drying hopper 5 has not reached a predetermined amount after the suction stop step (S7) is adopted, the suction blower 4 is driven (S11).

That is, in any case where the decompression step (S6) and the suction stop step (S7) are employed, if the material in the drying hopper 5 has not reached the predetermined amount, the branch decompression line 23 is closed and the branch suction is performed. The line 22 is opened, and the suction blower 4 is driven.
As a result, the opening / closing valve 20 is swung toward the material supply port 19 by the suction force of the suction blower 4, the material supply port 19 is closed, and the material is transported to the loader hopper 3.

Then, after a predetermined time has elapsed (S3), the pressure in the drying hopper 5 is detected (S4) in the same manner as described above, and based on the detected pressure in the drying hopper 5 (S5), the pressure reducing step ( Employing S6) or the suction stop step (S7), the material is supplied to the drying hopper 5 and dried (S8).
Thereafter, in the same manner as described above, it is measured whether the material in the dry hopper 5 has reached a predetermined amount (S9). Then, a predetermined amount of material can be stored in the dry hopper 5 by repeating the above steps until the amount of material supplied to the dry hopper 5 reaches a predetermined amount.

After the material in the drying hopper 5 reaches a predetermined amount, for example, the driving of the suction blower 4 and the operation of the switching operation valve 21 are ended (processing is ended), while the blower unit 6 is on the other hand. The predetermined amount of material supplied into the drying hopper 5 is continuously dried by continuing the air blowing.
Thereby, a predetermined amount of material can be dried with the drying apparatus 1.

After the drying of the material is finished, although not shown, if necessary, the material is discharged from the material discharge port 9 and connected to a processing device (for example, a molding machine, a mixer, etc.) connected to the material discharge port 9. Supply material.
According to such a drying apparatus 1, the inside of the drying hopper 5 can be decompressed only when necessary, and the material can be supplied with high accuracy.

That is, in such a drying apparatus 1, by switching the switching operation valve 21, the inside of the drying hopper 5 can be decompressed and the inside of the loader hopper 3 can be sucked according to the above steps as necessary. Therefore, the material can be supplied with high accuracy, and the material can be reliably dried with good workability.
Further, according to such a drying apparatus 1, the controller 26 can uniformly switch between the decompression of the drying hopper 5 and the suction of the loader hopper 3. As a result, the material supply accuracy can be improved, and the material can be reliably dried with good workability.

In this method, for example, in the pressure reducing step, after the pressure inside the drying hopper 5 is reduced, the suction blower 4 can be stopped if necessary, but preferably the suction blower 4 is continuously driven. Let
According to such a drying apparatus 1, the material can be transported and supplied while continuing the driving of the suction type blower 4, so that the material can be dried with better workability.

And according to this drying apparatus 1, the improvement of supply precision, such as a granular material as a material, can be aimed at. Moreover, this drying apparatus 1 is excellent in cost performance and workability.
FIG. 3 is a schematic view showing another embodiment of the drying apparatus of the present invention. In addition, about the member corresponding to each above-mentioned part, the same referential mark is attached | subjected in FIG. 3, and the detailed description is abbreviate | omitted.

In FIG. 3, a mounting portion 28 is formed in the drying device 1.
The attachment portion 28 is partitioned as a portion where the drying hopper 5 protrudes upward in the vertical direction.
Specifically, the attachment portion 28 is formed in a cylindrical shape sharing an axis with the drying container portion 7, communicates with the inside of the drying container portion 7, and protrudes upward from the drying upper wall portion 8. It is provided continuously from the part 8. The upper end portion of the attachment portion 28 is covered with the upper wall.

The material supply port 19 of the loader hopper 3 is disposed in the middle of the mounting portion 28 in the vertical direction, and the branch pressure reducing line 23 is connected to the side wall of the mounting portion 28.
According to such a drying apparatus 1, the material supply port 19 and the branch decompression line 23 are connected to the drying hopper 5 even when the inside of the drying hopper 5 is pressurized by the blower unit 6 to an atmospheric pressure or higher. Since the portion is surrounded by the attachment portion 28, if the pressure in the drying hopper 5 is reduced by the suction blower 4, only the pressure around the material supply port 19 surrounded by the attachment portion 28, not the entire drying container portion 7. Can be controlled. Therefore, the material supply port 19 provided in the loader hopper 3 can be opened by the own weight of the on-off valve 20 and the weight of the material, and the material supply accuracy can be further improved.

Moreover, in this drying apparatus 1, in order to suppress that the pressure state of the area | region enclosed by the attaching part 28 in the drying hopper 5 adjoins to the pressure state of an other area | region, the attaching part 28 is required as needed. Can be partially covered with a partition wall 31 to isolate the mounting portion 28 (see the broken line in FIG. 3).
For example, the partition wall 31 is formed on the lower side of the attachment portion 28 so as to partially cover the attachment portion 28. More specifically, the partition wall 31 is formed integrally with, for example, the drying upper wall portion 8, and has a smaller diameter on the lower surface of the drying upper wall portion 8 as it goes downward in the vertical direction. It is formed as a conical cylinder. Thereby, the attachment part 28 is partially covered.

DESCRIPTION OF SYMBOLS 1 Drying device 2 Dryer 3 Loader hopper 4 Suction type blower 5 Drying hopper 6 Blower unit 19 Material supply port 20 On-off valve

Claims (8)

A dryer provided with a drying hopper to which materials are supplied, and a blowing means for supplying a drying medium to the drying hopper;
A temporary storage tank that is disposed above the dryer and includes a material supply port that communicates with the drying hopper, and an open / close valve that opens the material supply port by its own weight and the weight of the material, and stores the material;
A drying apparatus comprising: a decompression unit for decompressing the inside of the drying hopper. The temporary storage tank is a loader hopper,
The drying apparatus according to claim 1, further comprising suction means for sucking the loader hopper to pneumatically transport the material.   The drying apparatus according to claim 2, wherein the suction unit also serves as the decompression unit. A branch suction line connected to the loader hopper and sucking the loader hopper;
A branch decompression line connected to the drying hopper and decompressing the inside of the drying hopper;
Switching means connected to the branch suction line and the branch decompression line, for switching between the decompression of the drying hopper and the suction of the loader hopper;
The drying apparatus according to claim 3, further comprising a suction-decompression line connected to the switching unit and the suction unit.   The drying apparatus according to claim 4, wherein a filter is provided between the switching unit and the suction unit in the suction-decompression line. The drying hopper has a mounting portion protruding upward in the vertical direction;
The material supply port is disposed in the mounting portion;
The drying apparatus according to claim 4, wherein the branch decompression line is connected to the attachment portion. A pressure detection sensor for detecting the pressure in the drying hopper, and a control means for controlling the switching means,
The drying apparatus according to claim 4, wherein the control unit controls the switching unit based on a signal from the pressure detection sensor. The control means has a transportation-drying switching program,
The transportation-drying switching program is
A blowing step of supplying a drying medium to the drying hopper by the blowing means;
A suction line opening step for closing the branch decompression line and opening the branch suction line by the switching means;
A material transport step of sucking the loader hopper by the suction means, closing the material supply port with the on-off valve, and transporting the material to the loader hopper;
A pressure detection step of detecting the pressure in the drying hopper by the pressure detection sensor after elapse of a predetermined time from the start of transportation of the material;
When the pressure in the drying hopper detected in the pressure detection step is equal to or higher than a predetermined pressure, the switching means closes the branch suction line while continuing the suction, and the material to the loader hopper is blocked. A decompression step of stopping transportation and opening the branch decompression line to decompress the inside of the drying hopper;
A suction stop step for stopping suction when the pressure in the drying hopper detected in the pressure detection step is less than a predetermined pressure;
After the pressure reducing step or the suction stop step, the material supply port is opened by the weight of the opening / closing valve and the weight of the material, the material stored in the loader hopper is supplied to the drying hopper, and the material is supplied by a drying medium. The drying apparatus according to claim 7, further comprising a drying step for drying.

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