JPH1096336A - Powder transport device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powder transport device which can surely transfer powder in a silo into a transport pipe without becoming larger or more complex. SOLUTION: A first rotary feeder 6 transferring powder in a silo 2 toward the underside of the silo 2, a sub-tank 7 provided below the first rotary feeder 6 to permit the dropping of the powder from the first rotary feeder 6, and a rotor having blades on its outer periphery are rotated within a housing provided below the sub-tank 7. The device has a second rotary feeder 8, by which the powder thus passed through the sub-tank 7 is transferred to a transport tube, and has an air vent formed in the sub-tank 7 so that air taken into the housing and raised when conveyed as the rotor of the second rotary feeder 8 rotates is discharged out of the sub-tank 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder transporting device for transporting powder by using air flow, and more particularly to a powder transporting device suitable for transporting powder having a low specific gravity. is there.

[0002]

2. Description of the Related Art Conventionally, as an apparatus for transporting powder using the flow of air, for example, an apparatus shown in FIG. 6 is known. The powder transport device 51 is for transporting cement as powder stored in the silo 52 to the sub-silo 54, and transports the blower (blower) 53 and the air from the blower 53 to the sub-silo 54. Tube 55,
And a rotary feeder 56 for sending the powder in the silo 52 to the transport pipe 55. The rotary feeder 56
The housing 57 includes a housing 57 disposed in the middle of the transport pipe 55, and a rotor 58 having vanes on the outer periphery and rotated in the housing 57. Then, the powder in the silo 52 is fluidized by air from the air device, falls on the rotor 58, and is transferred to the lower part of the housing 57 with the rotation of the rotor 58. The powder is sent to the sub-silo 54 while being mixed with air flowing through the transport pipe 55.

[0003] Apart from the above-mentioned type, there is also known an apparatus in which a negative pressure is applied to a silo to suck powder in the silo and transport the powder to a sub-silo.

[0004]

During the operation of the former powder transport device 51, part of the air flowing through the transport pipe 55 rises in the housing 57 with the rotation of the rotor 58, and this causes the powder to fall. Try to prevent. On this occasion,
If the powder is relatively heavy, such as the cement described above, the powder falls onto the rotor 58. And
The powder is transferred to the lower portion of the housing 57 by the rotation of the rotor 58. However, if the powder is a light powder such as sawdust, foamed resin, or the like, the powder is blown up by the ascending air, so that the powder is unlikely to fall on the upper portion of the rotor 58. Therefore, the powder transport device 51 is not suitable for transporting such a powder having a low specific gravity.

[0005] Further, when the powder in the silo is sucked as described above using the latter powder transport device, equipment and piping for the suction are required, and the device becomes large and complicated. Inevitable. For this reason, the powder transport device becomes more expensive than when powder is transported by air.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a powder transport device capable of reliably transferring powder in a silo to a transport pipe without increasing the size and complexity.

[0007]

According to a first aspect of the present invention, a powder stored in a silo is guided to a transport pipe through which air is sent, and transported along with the flow of the air. In the powder transport device as described above, powder in the silo,
A first powder transfer means for transferring the silo below, a sub-tank provided below the first powder transfer means and allowing the powder to fall from the first powder transfer means; By rotating a rotor having blades in a housing provided below the sub-tank, second powder transferring means for transferring the powder passing through the sub-tank to the transport pipe, and inside and outside the sub-tank And an air vent hole for discharging air that enters the housing from the transport pipe and rises by being conveyed with the rotation of the rotor of the second powder transport means to the outside of the sub-tank. It is provided.

According to the first aspect of the present invention, the powder stored in the silo is transferred below the silo by the first powder transferring means. This powder tends to fall in the sub tank by its own weight. On the other hand, the air flowing in the transport pipe moves upward with the rotation of the rotor when passing through the housing of the second powder transfer means. The air enters the sub tank and tries to rise. This air is led out of the sub-tank through the air vent hole. That is, the air sent from the blower or the like and entering the sub-tank is removed by being led out from the air vent hole. In the sub-tank, the force (pressure) of air for pushing up the powder against the weight of the powder becomes smaller as compared with the case without the air vent hole. Therefore, even when the specific gravity of the powder is light, the powder easily falls through the sub-tank onto the rotor of the second powder transfer means. Then, the dropped powder is transferred to the lower part of the housing by the rotation of the rotor. The powder mixes with the low-pressure air flowing through the transport tube and is transported on the flow of the air.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, a tubular member is mounted outside the sub tank at a position corresponding to the air vent hole.

According to the second aspect of the invention, the powder temporarily dropped from the first powder transfer means and passing through the sub-tank is the second powder.
Even if the powder tries to escape from the air vent hole on the rising air from the powder transfer means, the powder is easily separated from the air when passing through the tubular member. Therefore, it is possible to discharge only air from the tubular member to the outside of the sub tank.

According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the storage state detecting means for detecting the storage state of the powder in the sub-tank; When the state detecting means detects that the powder is stored in the sub-tank, the apparatus further comprises control means for stopping the transfer of the powder by the first powder transferring means.

If, for some reason, all the powder from the first powder transfer means is not transferred to the transport pipe by the second powder transfer means but accumulates in the sub-tank, the powder hardens. In some cases, it may be difficult to transfer by the second powder transferring means. On the other hand, in the third aspect, the storage state of the powder in the sub tank is monitored by the storage state detection unit. When the storage state detecting means detects that the powder has been stored in the sub tank, the control means stops the transfer of the powder by the first powder transferring means. Therefore, it is possible to grasp the occurrence of the trouble (the fact that the powder is not normally sent to the transport pipe) and to deal with it.

According to a fourth aspect of the present invention, in addition to the configuration of the third aspect, the invention further comprises a compressed air injection means for injecting compressed air toward the inside of the sub-tank.

According to the fourth aspect, in the third aspect, after the transfer of the powder by the first powder transferring means is stopped, the compressed air is injected to the inside of the sub tank by operating the compressed air injection means. Inject. Due to the impact caused by the collision of the compressed air, the powder stored and hardened in the sub tank collapses. Then, the transfer of the powder to the transport pipe by the second powder transfer means becomes possible.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, a powder transport device 1 of the present embodiment transfers powder stored in a silo 2 through transport pipes 4, 5 (low-pressure air from a lower opening of the silo 2). (See FIG. 4), and transported to another silo or the like (hereinafter referred to as a sub-silo) along with the flow of air. The powder to be transported by the powder transporting apparatus 1 is a very light powder having a specific gravity of about 0.1 to 0.3, such as sawdust and foamed resin.

The powder transport device 1 includes a first rotary feeder 6 as a first powder transport means, a sub-tank 7, and a second
The second rotary feeder 8 as a powder transfer means is a main component. As shown in FIG. 1 and FIG.
The rotary feeder 6 includes a housing 9 disposed below the silo 2. The housing 9 has a cylindrical shape with upper and lower ends open, so that the powder 3 can pass through. A rotor 11 is rotatably supported in the housing 9 by a shaft 14 in a direction indicated by an arrow in FIG.
The rotor 11 includes a disk-shaped main body 12 attached to a shaft 14 so as to be integrally rotatable, and a plurality of blades 13 extending radially from the main body 12 at equal angles.

The shaft 14 is drivingly connected by a chain 17 to a rotating shaft 16 of an electric motor 15 installed near the side of the first rotary feeder 6. Therefore, the rotation of the rotating shaft 16 due to the operation of the electric motor 15 is transmitted to the shaft 14 by the chain 17, and this shaft 14
Is driven to rotate integrally with the rotor 11. The powder 3 that has entered between the adjacent blades 13 and 13 is transported downward along the wall surface of the housing 9 as the rotor 11 rotates.

As shown in FIGS. 1 and 5, the sub-tank 7 is disposed below the first rotary feeder 6. The sub-tank 7 has a cylindrical shape whose upper and lower ends are open, and the powder 3 can pass through. In the sub tank 7,
A funnel-shaped hopper 18 is formed. In other words, the inner wall surface 18a of the hopper 18 has a tapered surface whose diameter is reduced toward the lower side.

As shown in FIGS. 1, 3 and 4, the second rotary feeder 8 has a housing 19 arranged below the sub tank 7. An opening 21 is formed in the upper part of the housing 19, and the powder 3 in the sub tank 7 can enter the housing 19 through the opening 21. A pair of through holes 22 are formed in a lower portion of the housing 19. In the lower part of the housing 19, transport pipes 4 and 5 are connected to locations corresponding to the through holes 22 and 22, respectively. One transport pipe 4
Is connected to a blower (blower) not shown, and the other transport pipe 5 is connected to a sub-silo not shown. The flow of air generated by the operation of the blower is transferred to the transport pipe 4, the through hole 22, the internal space of the housing 19,
2 and the transport pipe 5 in order, it is led to a sub-silo.

In the housing 19, the rotor 23 is
6 are rotatably supported in the direction indicated by the arrow in FIG. The rotor 23 includes a disk-shaped main body 24 mounted on a shaft 26 so as to be integrally rotatable, and a plurality of blades 25 extending radially from the main body 24 at equal angles. The shaft 26 is provided with the second rotary feeder 8.
Is driven and connected by a chain 29 to a rotating shaft 28 of an electric motor 27 installed near the side of. Therefore, the rotation of the rotating shaft 28 accompanying the operation of the electric motor 27 is transmitted to the shaft 26 by the chain 29, and this shaft 2
6 is driven to rotate integrally with the rotor 23. And
The powder 3 that has entered the space between the adjacent blades 25 through the opening 21 is transferred downward along the wall surface of the housing 19 as the rotor 23 rotates. When the powder 3 is sent to a position corresponding to the through holes 22 at the lower portion of the housing 19, the powder 3 is mixed with the air and sent out of the housing 19, and transported to the sub-silo through the transport pipe 5. Is done. The second rotary feeder 8 has a higher ability to transfer the powder 3 than the first rotary feeder 6.

As shown in FIG. 5, air vent holes 31, 31... Are formed at a plurality of locations (for example, three to four locations) on the outer periphery of the upper portion of the hopper 18, and the sub-tank is formed by these air vent holes 31. The inside and outside of 7 are communicated. In the upper surface of the hopper 18, each air vent hole 3
The tubular members 32, 32,... One end of each tubular member 32 is fixed to the hopper 18. Each tubular member 32 extends diagonally upward,
It is bent down on the way. The distal end of each tubular member 32 is open downward.

Further, as shown in FIGS. 1 and 5, the hopper section 18 is provided with a level sensor 33 as a storage state detecting means for detecting the storage state of the powder 3 in the sub tank 7. The level sensor 33 detects the height of the mass 36 of the powder 3 when the powder 3 is stored in the sub tank 7. In order to control the operation of the electric motor 27 based on the detection signal of the level sensor 33, a controller 34 as control means is used. Controller 3
4 permits the operation of the electric motor 27 when the upper surface of the mass 36 by the level sensor 33 is lower than a predetermined position, that is, when the powder 3 is not accumulated as the mass 36 in the hopper 18. In contrast, the hopper 1
When a mass 36 is formed in the upper surface 8 and its upper surface is higher than a predetermined position, the controller 34 forcibly stops the electric motor 27.

Further, a bin blow 35 as a compressed air injection means is incorporated in a lower portion of the sub tank 7. The bin blow 35 is a device that injects compressed air toward the mass 36 of the powder 3 accumulated in the sub-tank 7 and instantaneously applies a large impact to the mass 36 with the compressed air to break the mass.

Next, the operation and effects of the powder transport device 1 configured as described above will be described.

First, the lump 3 of the powder 3 is placed in the sub tank 7.
6 does not occur, the level sensor 3
3 is detected. The controller 34 allows the operation of the first rotary feeder 6 based on the detection result of the level sensor 33. The powder 3 stored in the silo 2 enters the upper part of the first rotary feeder 6. This powder 3
Is transferred to the lower part of the housing 9 with the rotation of the rotor 11, and then tries to fall into the sub tank 7 by its own weight.

On the other hand, when air from the blower enters the housing 19 of the second rotary feeder 8 through the transport pipe 4 and the through hole 22, it is sent upward along with the rotation of the rotor 23, and is sent from the opening 21 to the sub-tank 7. Try to get in and climb. The rising air passes through the air vent hole 31 and the tubular member 32 in order and is led out of the sub-tank 7.
That is, although the rising air from the second rotary feeder 8 once enters the sub-tank 7, the air vent hole 31
And being removed from the tubular member 32. As described above, the rising air is not confined in the sub tank 7 and escapes from the air vent hole 31. Sub tank 7
Inside, the rising air resists the weight of the powder 3
The force (pressure) for pushing up is smaller than that without the air vent hole 31.

Therefore, even when the specific gravity of the powder 3 is very light, as described above, the ascending air is supplied to the air vent hole 31.
The powder 3 falls in the sub-tank 7 during the period in which the powder 3 escapes. When the powder 3 falls, an air flow (wind) is generated, but the air escapes from the air vent hole 31.
After passing through the sub-tank 7, the powder 3 falls on the rotor 23 of the second rotary feeder 8, and is transferred to a position corresponding to the through hole 22 in the lower portion of the housing 19 by the rotation of the rotor 23. The powder 3 is mixed with the low-pressure air flowing through the transport pipe 4 and is transported to the sub-silo via the transport pipe 5 on the air flow.

In the present embodiment, the second rotary feeder 8 having a larger transfer capacity than the first rotary feeder 6 is used. For this reason, if each part of the powder transport device 1 is operating normally, the first rotary feeder 6
The powder 3 that has fallen from is transported to the lower portion of the second rotary feeder 8 and transported through the transport pipe 5 together with air. Therefore, the problem that the powder 3 is not completely transported by the second rotary feeder 8 and accumulates in the sub tank 7 hardly occurs.

For some reason, the powder 3 is placed in the sub tank 7
If it accumulates inside, it is detected by the level sensor 33. That is, the level sensor 33 detects that the agglomeration 36 of the powder 3 has occurred and the upper surface thereof has become higher than a predetermined position. Then, the controller 34 sends the powder 3 to the rotor 2 of the second rotary feeder 8.
3, it is determined that the powder 3 is no longer supplied to the transport pipe 5 and the operation of the electric motor 15 of the first rotary feeder 6 is forcibly stopped. Then, the drop of the powder 3 by the first rotary feeder 6 is stopped.

Subsequently, the bin blow 35 is operated to apply compressed air to the mass 36. Then, the mass 36 is broken by the impact of the compressed air. At this time, the inner wall surface 18a of the hopper 18 in the sub tank 7 is inclined. For this reason, the powder 3 broken as described above easily moves downward along the inner wall surface 18a by its own weight. The powder 3 enters a space between the adjacent blades 25 of the rotor 23 and is transferred downward along the inner wall surface of the housing 19 as the rotor 23 rotates. When the powder 3 is sent to a position corresponding to the through hole 22 at the lower portion of the housing 19, the powder 3 is mixed with low-pressure air, sent out of the housing 19, and transported through the transport pipe 5 to the sub-silo. .

When the powder 3 accumulated in the sub-tank 7 disappears, that is, when the lump 36 is removed and the sub-tank 7 is completely empty, the first rotary feeder 6 is operated again, and Then, the transfer of the powder 3 in the silo 2 is restarted.

As described above, in the present embodiment, the above-described air vent hole 31 serves to guide the rising air blown up from the second rotary feeder 8 to the outside of the sub-tank 7,
It has a function of creating an air flow for moving (falling) the powder 3 from the rotary feeder 6. For this reason, when the second rotary feeder 8 is operated, the air that has entered the housing 19 from the transport pipe 4 rises with the rotation of the rotor 23, but the air is discharged from the air vent hole 31 to the outside of the sub tank 7. In addition, it is possible to prevent the air from hindering the powder 3 from falling. Moreover, in order to obtain this effect, basically, a conventional device for transporting powder using air from a blower is diverted, and only a first rotary feeder 6 and a sub-tank 7 are added thereto. Therefore, the powder 3 in the silo 2 can be dropped onto the rotor 23 and reliably transferred to the transport pipe 5 without increasing the size and complexity of the powder transport device 1.

In this embodiment, a plurality of tubular members 32 are attached to the sub-tank 7 at locations corresponding to the air vent holes 31. Therefore, even if the air that rises with the rotation of the rotor 23 tries to escape from the air vent hole 31 together with the powder 3 in the sub-tank 7, the powder 3 is removed from the air when passing through the tubular member 32. Easy to be separated. Therefore, it is possible to efficiently discharge only the air to the outside of the sub-tank 7 and make it difficult to discharge the powder 3. In addition, an intermediate portion of each tubular member 32 is bent and has a distal end opening downward. For this reason, even when the powder transport device 1 is installed outdoors, it prevents raindrops from entering the sub-tank 7 through the tubular member 32 and prevents the powder 3 in the sub-tank 7 from getting wet. Can be prevented.

Further, in the present embodiment, the level sensor 33 detects whether or not the powder 3 is stored in the sub-tank 7, and when the powder 3 is stored, the rotation of the rotor 11 is stopped, and the first rotary feeder 6 is stopped. Forcibly stops the transfer of the powder 3. Therefore, even if the powder 3 is stored in the sub-tank 7 and hardened for some reason, the fact is grasped at an early stage,
It is possible to cope with the problem (the transportation stop of the powder 3).

As one of the measures, in the present embodiment, a device (bin blow 35) for injecting compressed air toward the inside of the sub-tank 7 is provided in the powder transport device 1. Therefore, after the transfer of the powder 3 by the first rotary feeder 6 is stopped as described above, the bin blow 35 is operated to inject the compressed air, whereby the mass 36 in the sub tank 7 can be broken. . The disintegrated powder 3 is passed through the through-hole
2 can be transported to the target location by air from the transport pipe 4.

The present invention can be embodied in another embodiment shown below. (1) In the above embodiment, the configuration is such that the air in the sub-tank 7 naturally escapes from the air vent hole 31. However, the air may be forced out of the sub-tank 7 using a blower or the like.

(2) The hopper 18 of the sub tank 7 may be omitted, and the shape of the sub tank 7 may be changed to a cylindrical shape having substantially the same diameter in any part.

(3) In the above embodiment, the tubular member 32 is formed by bending the intermediate portion. However, a straight member having no bent portion may be used instead.

[0039]

As described above, according to the first aspect, the powder in the silo can be reliably transferred to the transport pipe without increasing the size and complexity.

According to the second aspect, in addition to the effect of the first aspect, the powder in the sub-tank can be prevented from coming out of the air vent together with the air.

According to the third aspect of the invention, in addition to the effects of the first or second aspect, it is possible to quickly grasp that the powder is stored in the sub-tank and solidified, and to cope with the problem. Can be.

According to the fourth invention, in addition to the effect of the third invention, the powder solidified in the sub tank is broken, and the powder is reliably transferred to the transport pipe by the second powder transfer means. Can be.

[Brief description of the drawings]

FIG. 1 is a partial front view showing a powder transport device according to an embodiment of the present invention.

FIG. 2 is a sectional view showing an internal structure of a first rotary feeder in FIG.

FIG. 3 is a partial cross-sectional view showing a lower structure of the powder transporting device of FIG.

FIG. 4 is a partial plan view showing a lower structure of the powder transport device of FIG.

FIG. 5 is a partial cross-sectional view showing a sub tank in the powder transport device of FIG.

FIG. 6 is a schematic front view showing a conventional powder transport device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 powder transport device 2 silo 3 powder 4,5 transport pipe 6 first rotary feeder as first powder transport means 7 subtank 8 second rotary feeder as second powder transport means 19 housing 23 rotor 25 blade 31 Air vent hole 32 Tubular member 33 Level sensor as storage state detection means 34 Controller as control means 35 Bin blow as compressed air injection means

Claims (4)

[Claims] 1. A powder transport device for guiding powder stored in a silo to a transport pipe through which air is sent, and transporting the powder along the flow of air, wherein the powder in the silo is transported. The first to transfer the body below the silo
A powder transfer means, a sub-tank provided below the first powder transfer means and allowing the powder to fall from the first powder transfer means, and a rotor having blades on the outer periphery. A second powder transferring means for transferring the powder having passed through the sub-tank to the transport pipe by rotating in a housing provided on a lower side, and a hole for communicating between the inside and the outside of the sub-tank; And an air vent hole for discharging air rising from the sub-tank into the housing through the rotation of the rotor of the second powder transfer means. Transport equipment. 2. The powder transporting device according to claim 1, wherein a tubular member is mounted outside the sub-tank at a position corresponding to the air vent hole. 3. A storage state detection means for detecting a storage state of the powder in the sub-tank, and when the storage state detection means detects that the powder is stored in the sub-tank, the first powder 3. The apparatus according to claim 1, further comprising control means for stopping the transfer of the powder by the transfer means. 4. The powder transport apparatus according to claim 3, further comprising a compressed air injection unit that injects compressed air toward the inside of the sub-tank.