JP3016762U - Powder transport device - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the power consumption of an electric fan for exhaust and to prevent uneven distribution of powder particles of different materials in a temporary storage tank. A gas-tight first pipe, which is provided with a conveying pipe 6 for conveying powder and granular material, a first valve 8 connected to the end of the conveying pipe 6 at the bottom, and a filter 3 installed above the connecting portion of the conveying pipe. Hopper 1 and the filter 3 of this first hopper 1
Electric exhaust means for exhausting air from above the exhaust pipe 7 through the exhaust pipe 7,
A similarly airtight second hopper 1A provided below the first hopper 1 and adjacent to the first hopper 1 via the first valve 8 and having a second valve 9 at the bottom thereof; A temporary storage tank 2 at atmospheric pressure, which is arranged below and adjacent to the second valve 9 to temporarily store the conveyed granular material, and controls the opening and closing of the first valve 8 and the second valve 9. And a control panel, which is configured to include a control device, and a powder and granular material conveying device. [Effect] The power consumption of the electric fan is reduced, and uneven distribution of powder particles of different materials is suppressed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to the transportation of powders and granules, and more particularly to a transporter for powders and granules which is a raw material for plastic molding.

[0002]

[Prior art]

 Conventionally, powders and granules, which are the raw material for plastic molding, have been vacuum-conveyed from the storage tank to the vicinity of the processing equipment by a device equipped with a cyclone type first hopper as shown in Fig. 7. There is. An electric exhaust fan (not shown) is connected to the exhaust pipe 7, and the first hopper 1 is evacuated. A carrier pipe 6 is connected to the first hopper 1 in a tangential direction with respect to the body of the hopper, and the other end of the carrier pipe 6 is connected to a storage tank for the powder or granular material as a raw material. When the pressure of the first hopper 1 is reduced by being exhausted by the electric fan, a flow of air from the storage tank to the first hopper 1 is generated in the transfer pipe 6, and the granular material in the storage tank is carried along with this air flow. It flows into the first hopper 1 through the pipe 6. The air that has flowed into the first hopper 1 forms a swirling flow and descends in the hopper, and the granular material is separated from the air and is deposited on the bottom of the first hopper 1. The air from which the powder and granules have been separated rises in the central portion of the hopper, passes through the filter 3, and is extracted through the exhaust pipe 7. If the inflow of the granules continues for a certain time, the amount of the granules in the first hopper 1 reaches the limit, the electric exhaust fan is stopped, the swing type lid 4 at the bottom of the first hopper 1 is opened, and the The granular material accumulated in the 1 hopper 1 falls into the temporary storage tank 2 below. When the particles in the first hopper 1 fall into the temporary storage tank 2 below, the lid 4 is closed, the electric fan is activated, and the particles are conveyed again. The raw material for plastic molding carried by such a method is a resin such as polyethylene, polypropylene, ABS, or styrene in the form of pellets having a diameter of 5 mm or less.

[0003]

[Problems to be solved by the device]

 Originally, the first hopper 1 was not intended to store powders and granules, but was intended to take out the powders and granules from the low-pressure (under atmospheric pressure) transfer pipe 6 to the temporary storage tank 2 under atmospheric pressure. , The size is also relatively small. If it is large, there are disadvantages such as high manufacturing cost, space saving, and it takes time to reduce the pressure to atmospheric pressure once it has been set, so it is made small. Therefore, it fills up in a short time, and the electric fan frequently stops and starts. For example, the electric fan repeatedly stops and starts every several tens of seconds, such as 20 seconds of operation, 20 seconds of stop, and 20 seconds of operation and then 20 seconds. As a result, the number of times a high starting current has flowed has increased, and power consumption has increased.

[0004] Further, the powder particles to be conveyed are often mixed with powder particles having different materials and specific gravities, for example, pellets, and the transfer pipe 6 is not limited to a horizontal portion but is inclined. It usually contains parts. Therefore, when the electric fan stops and the transportation stops, the granular material that has passed through the sloped portion falls downward, but at that time, due to the difference in specific gravity, heavy and light materials, that is, different materials are used. Things tend to collect separately. In this way, if the heavy and light items are separated in the conveyance pipe 6, when the conveyance is restarted, the heavy and light items are conveyed in the separated state and are transferred to the temporary storage tank 2. Even in the accumulated state, it is easy for the different materials to not mix well and to be unevenly distributed. If different materials do not mix well in the temporary storage tank 2 and are unevenly distributed, there will be differences in the materials among the parts to be molded. Measures such as providing a stirring means to prevent this will occur. Was needed.

An object of the present invention is to reduce the power consumption of an electric fan for exhaust and to suppress uneven distribution of powder particles of different materials in a temporary storage tank.

[0006]

[Means for Solving the Problems]

 The above-mentioned purpose is to convey a powder or granular material, an airtight first hopper connected to the end of the conveying pipe and having a first valve means at the bottom, and an electric exhaust gas exhausted from the first hopper. A granular material conveying apparatus comprising: a means and a temporary storage tank that is arranged below the first hopper to temporarily store the conveyed granular material, wherein Second air-tight hoppers adjacent to each other via the valve means, and the temporary storage tank is disposed below the second valve means provided at the bottom of the second hopper. It is achieved by providing a control panel that controls the opening and closing of the valve means.

The control panel is configured so that the other of the first valve means and the second valve means is opened only when the other one is closed, and the first valve means and the second valve means are provided. It is advisable to configure so that they open and close alternately.

In the first and second valve means, the valve body having the valve hole moves in the valve casing with the entire circumference of the valve body fitted in the valve casing. It is advisable to open or close the valve by matching or shifting the position of the position with the position of the casing valve hole provided in the valve casing. In this case, it is desirable that the valve casing be made of Teflon resin or high-density polyethylene and the valve body be made of stainless steel.

An air cylinder is preferably used as the means for moving the valve bodies of the first and second valve means.

Further, it is preferable that the control panel is provided with timer means for setting the length of time for maintaining the open state of the first and second valve means to an arbitrary value.

[0011]

[Action]

 First, the control panel conveys the granular material with the first valve means closed, and stores the conveyed granular material in the first hopper. The control panel also opens the second valve means to drop the granular material in the second hopper into the temporary storage tank and then closes it again. When the amount of powder or granules in the first hopper reaches a predetermined amount, the control panel opens the first valve means while the electric exhaust means is operating, and the powder or granules accumulated in the first hopper are discharged to the second position. Drop it into the hopper. When the granular material falls, the control panel closes the first valve means again, and the transported granular material is again stored in the first hopper. When the first valve means is closed, the second valve means is opened, and the granular material in the second hopper is dropped into the temporary storage tank. When the particles in the second hopper have finished falling into the temporary storage tank, the control panel closes the second valve means again. This cycle is repeated, and the granular material accumulated in the first hopper is discharged without stopping the electric exhaust means.

The control panel is configured so that the first valve means and the second valve means are opened only when one of them is closed, and the first valve means and the second valve means are opened. It is configured to open and close alternately, and when the first valve means is opened with the second valve means closed, and when the granular material in the first hopper has finished falling to the second hopper, or when a predetermined amount is reached. After a lapse of time, the first valve means is closed. After the first valve means is closed, the second valve means is opened, and when the granular material in the second hopper has finished falling into the temporary storage tank or after a predetermined time has passed, the second valve means is opened. To be closed. When the second valve means is closed, the first valve means is opened and the granular material in the first hopper falls into the second hopper. In this way, since either the first valve means or the second valve means is always closed, the first hopper exhausted by the electric exhaust means is not directly communicated with the outside air, and the electric It is possible to take out the transported granular material from the low-pressure portion to the temporary storage tank at atmospheric pressure while maintaining the transportation of the granular material by continuously operating the exhaust means.

In addition, in the first and second valve means, the valve body having the valve hole moves in the valve casing with the entire circumference of the valve body fitted in the valve casing, Since the valve is opened / closed by matching or shifting the position of the valve with the position of the casing valve hole provided in the valve casing, it is possible that powder particles are caught in the fitting groove of the valve element formed in the valve casing. can avoid.

By using Teflon resin or high-density polyethylene for the valve casing and using stainless steel for the valve body, it is possible to reduce friction when the valve body slides.

If an air cylinder is used as the means for moving the valve body of the first and second valve means, the opening / closing operation of the valve body can be performed swiftly and in a short time.

Further, the control panel is provided with timer means for setting the length of time for maintaining the open state of the first and second valve means to an arbitrary value, whereby The opening / closing timing of the valve means can be easily adjusted according to the amount.

[0017]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. The embodiment of the present invention shown in FIG. 1 is a cyclone-type first hopper 1 having a filter 3 installed therein and having an opening at the bottom and connected to a conveying pipe 6, and an exhaust connected to the top of the first hopper 1. The pipe 7, a first valve 8 attached to the bottom opening of the first hopper 1 to open and close the opening by moving a valve body in the horizontal direction, and the first valve 8 to the bottom opening of the first hopper 1. Of the second hopper 1A, the second hopper 1A airtightly connected via the second hopper 1A, the second valve 9 attached to the bottom opening of the second hopper 1A for moving the valve body in the horizontal direction to open and close the opening. The temporary storage tank 2 connected to the bottom opening through the second valve 9, switches 15 and 16 for detecting the open / closed state of the first valve 8 and the second valve 9, the first valve 8 and the second valve Electromagnetically driven switching valve 1 for controlling the air supplied to the air cylinders forming a part of , 11, and a control panel 14 for controlling the switching valves 10, 11 by using the outputs of the switches 15, 16 as inputs, and for driving the first valve 8 and the second valve 9 via the switching valves 10, 11. And an air pipe 12 for supplying compressed air.

The first valve 8 and the second valve 9 have the same configuration, and the configuration of the first valve will be described with reference to FIGS. The first valve 8 is a valve casing 8A having a flat rectangular shape and a flat oval hollow portion 8E inside, and is movable in a direction parallel to the flat surface of the hollow portion 8E inside the hollow portion 8E. A flat oval valve body 8C installed therein, an opening / closing cylinder 8B in which a piston rod is coupled to the valve body 8C via a drive shaft 8H, and a shaft seal 8D attached to a penetrating portion of the valve casing 8A of the drive shaft 8H. It is composed of and. The valve body 8C has the same size as that of the bottom opening of the first hopper 1 when the valve body 8C is located closest to the drive cylinder 8B side in the valve casing 8A. The hole 8F is provided, and the valve casing 8A is also provided with a casing valve hole 8G having the same size as the valve hole 8F at a position immediately below the bottom opening of the first hopper 1.

When the drive shaft 8H is pushed all the way into the valve casing 8A, the valve body 8C and the drive cylinder 8B completely disengage the valve hole 8F from the casing valve hole 8G, so that the casing valve hole 8G is separated from the valve body 8C. It is configured so that it is closed at the portion without holes. The valve body 8C was made of stainless steel (SUS304), and the valve casing 8A was made of a Teflon-based resin with low friction. If it is not a Teflon type resin, high density polyethylene is preferable.

The switch (SW1) 15 is attached to the end of the valve casing 8A opposite to the drive cylinder 8B, and when the drive shaft 8H is fully pushed into the valve casing 8A, the contact is closed to drive the switch. The contacts are closed when the shaft 8H moves in the direction of being pulled out from the valve casing 8A.

FIG. 4 shows how the switching valves 10 and 11 are connected to the drive cylinders 8B and 9B. Both of the switching valves 10 and 11 are in the excited state, and in the demagnetized state, the switching valve moves to the left in the figure.

FIG. 5 shows the configuration of the control panel 14. Reference numeral 10X indicates an exciting coil of the switching valve 10 that controls the air sent to the drive cylinder 8B, and reference numeral 11X indicates an exciting coil of the switching valve 11 that controls the air sent to the drive cylinder 9B. The relay 10Y opens and closes the contact 23 of the exciting coil 10X, and the relay 11Y opens and closes the contact 22 of the exciting coil 11X. One end of the relay 10Y is connected to one power supply line 19 via the switch (SW2) 16, and the other end is connected to the other power supply line 20 via the normally-closed contact 17 to connect the switch (SW2) 16 and the relay. A timer T1 whose operating time can be adjusted is connected between a conductor connecting 10Y and a power supply line 20. The timer T1 starts counting by energization, and operates to open the contact 17 after a set time has elapsed. When electricity stops flowing to the timer T1, the timer is reset and the contact 17 is closed. One end of the relay 11Y is connected to one power supply line 19 via the switch (SW1) 15 and the delay switch 21, and the other end is connected to the other power supply line 20 via the normally-closed contact 18, respectively. ) A timer T2 whose operating time can be adjusted is connected between the power supply line 20 and the conductor connecting 15 and the relay 11Y. The timer T2 starts counting by energization, and operates to open the contact 18 after a set time has elapsed. When electricity stops flowing to the timer T1, the timer is reset and the contact 18 is closed.

The operation of this embodiment will be described below. When the power is off, the switching valve is not excited and is therefore offset by the spring, which is the opposite of the state shown in FIG. That is, the compressed air is sent to the piston side of the drive cylinders 8B and 9B, and the first valve 8 and the second valve 9 are both closed. Therefore, the switches SW1, SW2, the contacts 17, 18 are both closed, and the contacts 22, 23 are closed.

When compressed air is supplied in this state and the control panel 14 is powered on, first the relay 10Y is excited, the contact 23 is closed, and the exciting coil 10X of the switching valve 10 is excited to switch the switching valve 10Y. Sends compressed air to the rod side of the drive cylinder 8B. As a result, the first valve 8 is first opened, and the powder particles accumulated in the first hopper 1 fall inside the second hopper 1A. When the first valve 8 is opened, the switch SW1 is opened. At the same time, timer T1 starts counting. On the other hand, on the relay 11Y side, the switch SW1 is closed when the power is supplied, but the delay switch 21 (the switch that turns on after a predetermined time has elapsed after the power is supplied) supplies the power. However, the relay 11Y is not excited because the first valve 8 is open and the switch SW1 is open at the time of energization. It will remain offset. That is, the second valve 9 remains closed. In this state, the electric fan for exhaust is activated to start the transportation of the powder or granular material. The granular material flowing into the first hopper passes through the open first valve 8 and falls into the second hopper 1A.

When the timer T1 counts up, the contact 17 is opened and the relay 10Y is demagnetized, so the contact 23 is opened, the exciting coil 10X of the switching valve 10 is demagnetized, and the flow direction of the compressed air is switched, and the first valve is opened. 8 is closed. The granular material that has flowed into the first hopper 1 is stored in the first hopper 1. The switch SW2 is still closed because the second valve 9 is closed, but the current is still flowing through the timer T1 so that the contact 17 is also open and the relay 10Y is not excited. When the first valve 8 is closed, the switch SW1 is closed and the delay switch 21 can be energized. Therefore, the relay 11Y is energized, the contact 22 is closed, and the exciting coil 11X of the switching valve 11 is energized to drive the cylinder. Compressed air is sent to the rod side of 9B and the second valve 9 is opened. At the same time, the timer T2 starts counting. When the second valve 9 is opened, the granular material accumulated in the second hopper 1A drops into the primary storage tank below. When the second valve 9 is opened, the switch SW2 is opened and the current to the timer T1 is cut off. Therefore, the timer T1 is reset and the contact 17 returns to the closed position.

When the timer T2 counts up, the contact 18 is opened and the relay 11Y is demagnetized, so the contact 22 is opened, the exciting coil 11X of the switching valve 11 is demagnetized, and the flow direction of the compressed air is switched. 2 valve 9 is closed. Although the switch SW1 remains closed because the first valve 8 is closed, the current remains flowing through the timer T2, so the contact 18 also remains open and the relay 11Y is not excited. When the second valve 9 is closed, the switch SW2 is closed and the contact 17 is also closed. Therefore, the relay 10Y is excited, the contact 23 is closed, the exciting coil 10X of the switching valve 10 is energized, and the rod of the drive cylinder 8B is closed. The compressed air is sent to the side and the first valve 8 is opened. The powder particles accumulated in the first hopper 1 while the first valve 8 is closed fall into the second hopper 1A. At the same time, the timer T1 starts counting. When the first valve 8 is opened, the switch SW1 is opened and the current to the timer T2 is cut off, so that the timer T2 is reset and the contact 18 is returned to the closed position.

As described above, while the timer T1 is counting, the first valve 8 is opened and the second valve 9 is closed, so that the granular material stored in the first hopper 1 is stored in the second hopper. The granular material that has fallen to 1A and has been conveyed passes through the open first valve 8 and drops to the second hopper, and while the timer T2 is counting, the first valve 8 is closed and the second valve is closed. 9 is opened, and the granular material conveyed is stored in the first hopper 1, and the granular material stored in the second hopper 1 A falls into the primary storage tank 2. In such a valve operation, for example, when the opened second valve 9 is closed and the closed first valve 8 is opened, the second hopper 1A is at atmospheric pressure and the first hopper 1 is at atmospheric pressure or less. It is operated at a low pressure, and when the first valve 8 is opened, some air is blown from the second hopper side to the first hopper side, but it does not cause a shock to the exhaust fan. The operation of the exhaust fan was extremely smooth even when the opening and closing of the first valve 8 and the second valve 9 were repeated every several tens of seconds.

The first valve 8 and the second valve 9 each have a valve body fitted inside a flat hollow portion inside the valve casing, and the periphery of the valve body is fitted into the hollow portion of the valve casing. The valve is opened and closed by moving or moving the valve body parallel to the position of the valve hole of the valve body and the position of the casing valve hole of the valve casing. Also in this case, the structure is such that the granular material does not enter the fitting portion between the valve body and the valve casing. Further, when the first valve is closed, the differential pressure between the first hopper and the second hopper is applied to the valve body, and when the second valve is closed, the differential pressure between the second hopper and the temporary storage tank is applied, and the valve body is closed by the valve casing. Airtightness is secured by being pressed against.

As described above, according to this embodiment, the second hopper, which can freely connect and isolate the first hopper 1 and the temporary storage tank, is provided between the first hopper 1 and the temporary storage tank. By interposing it, it is possible to continuously take out the powder particles that have been vacuum-transferred to the primary storage tank at atmospheric pressure without stopping the electric fan for exhaust, and the number of times the exhaust fan is started and stopped The consumption could be reduced. In addition, the number of times the exhaust fan was started and stopped was reduced, and it was possible to reduce the wear of the switch of the fan power supply. The set times of the timers T1 and T2 may be set appropriately according to the amount of powder or granules conveyed per minute and the capacity of the first hopper so that they do not accumulate in the first hopper. In the example shown in FIG. 5, the contact 23 is opened and closed by the relay 10Y, and the energization of the exciting coil 10X is turned on and off by opening and closing the contact 23. However, the exciting coil 10X is directly connected to the position of the relay 10Y. You may do it.

Further, since the number of times the exhaust fan is started and stopped is reduced, the powder or granules are less likely to stay in the transport pipe 6, and uneven distribution due to the difference in specific gravity of the powder or granules is less likely to occur. It was

In the above embodiment, the first valve 8 is automatically opened when the second valve 9 is closed, and the second valve 9 is opened when the first valve 8 is closed. However, as shown in FIG. 6, a contact point 23A is provided between the exciting coil 10X and the power supply line 20 to provide a detecting means for detecting whether or not the amount of the powder or granular material in the first hopper 1 has reached a predetermined amount. If the contact 23A is closed by the output of this detection means and this contact 23A is used as a self-holding contact, the amount of powder or granular material in the first hopper will be a predetermined amount even if the second valve 9 is closed. Until this is reached, the opening of the first valve 8 is suppressed, the number of times the valve is opened and closed is reduced, the amount of compressed air used can be reduced, and the life of the valve and cylinder can be extended. However, in this case, it is desirable to set the setting time of the timer T2 to the minimum time required for the powder and granules accumulated in the second hopper to drop into the temporary storage tank.

[0032]

[Effect of device]

 According to the present invention, the granular material can be taken out from the first hopper without stopping the operation of the electric exhaust means, and the electric exhaust means can be continuously operated, so that the power consumption can be reduced. In addition, the number of times the powder or granules stop in the transport pipe decreases, and when powders or granules with different specific gravities are mixed and transported, uneven distribution of powder or granules in the temporary storage tank is reduced, and Material variations are reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an overall configuration of an embodiment of the present invention.

FIG. 2 is a sectional view showing details of a portion of FIG.

3 is a cross-sectional plan view taken along the line AA of FIG.

FIG. 4 is a piping system diagram showing details of a portion of the embodiment shown in FIG.

5 is a single-line connection diagram showing a control sequence of the embodiment shown in FIG.

FIG. 6 is a single line connection diagram showing a partially modified example of the embodiment shown in FIG.

FIG. 7 is an overall configuration diagram showing an example of a conventional technique.

[Explanation of symbols]

1 1st hopper 1A 2nd hopper 2 Temporary storage tank 3 Filter 4 Lid 6 Conveying pipe 7 Exhaust pipe 8 1st valve 8A Valve casing 8B Drive cylinder 8C Valve body 8D Shaft seal 8E Hollow part 8F Valve hole 8G Casing valve hole 9th 2 valves 9A valve casing 9B drive cylinder 9C valve body 9D shaft seal 9E hollow part 9F valve hole 9G casing valve hole 10 switching valve 11 switching valve 12 compressed air pipe 14 control panel 15 switch S
W1 16 switch SW2 17,18 contacts 19,20 power line 21 delay switch 22,23,23A contacts

Claims (8)

[Scope of utility model registration request] 1. An airtight cyclone-type first hopper which is provided with a conveying pipe for conveying powder and granular material, a first valve means connected to the end of the conveying pipe, and exhausted from the first hopper. A powder and granular material conveying device comprising: an electric exhaust means; and a temporary storage tank that is arranged below the first hopper and temporarily stores the powder and granular material that has been conveyed. An airtight second hopper adjacent to the first valve means is provided, and the temporary storage tank is disposed below the second valve means provided at the bottom of the second hopper. A powdery or granular material conveying device, characterized in that a control panel for controlling opening and closing of the valve means is provided. 2. The control panel is configured so that the first valve means and the second valve means are opened only when one of them is closed, and the first valve means and the second valve means are opened. Is controlled so as to open and close alternately.
The powder / granular material conveying device according to. 3. A valve casing having a casing valve hole penetrating from one surface to the other surface of the first and second valve means, and a hollow portion including the casing valve hole, and the hollow portion. A valve body internally movably in the hollow portion with the entire circumference of the valve body fitted in a valve casing, and a valve hole of substantially the same size as the casing valve hole formed in the valve body. And a drive means for moving the valve body within the valve casing, wherein the valve body is moved by the drive means to position the valve hole of the valve body in the casing valve hole provided in the valve casing. The powder or granular material conveying device according to claim 1 or 2, wherein the valve is opened and closed by matching or shifting the position. 4. The powder / granular material conveying device according to claim 1, wherein the valve casing is made of Teflon resin or high-density polyethylene, and the valve body is made of stainless steel. 5. The powder or granular material is a mixture of pellets of a plurality of materials which are raw materials for plastic molding, and the transfer pipe is
The powdery or granular material conveying device according to any one of claims 1 to 4, wherein the powdery or granular material conveying device has a portion that is inclined in the vertical direction. 6. The powder particles according to claim 1, wherein the first and second valve means have a valve element that is reciprocally driven by an air cylinder. Body transport device. 7. The control panel comprises timer means for setting the length of time for maintaining the open state of the first and second valve means to an arbitrary value. 6. The powdery- or granular-material conveying device according to any one of 6. 8. A control panel for detecting that the amount of the powder or granular material in the first hopper has reached a predetermined amount, and a device for opening the first valve means based on the output of the detecting device. The powdery- or granular-material conveying device according to any one of claims 1 to 7, which comprises: