JPH0479928B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a pneumatic transport device for plug transporting granular material.

[Conventional technology and its problems]

It consists of a closed pressure tank and a transport pipe connected to the tank, and by supplying compressed air in pulses to the transport pipe, the granular material discharged from the closed pressure tank is transported as a plug along the transport pipe. A pneumatic transport device is known. Plug transport is the formation of alternately pressurized air (pulses) and powder aggregate layers (plugs) in a transport pipe, and the pressure that passes through the plug due to the pressure difference between two pulses adjacent to the plug. This is a method of propelling granular material using the acting force of air, or "wedge force," but if the granular material in a closed pressure tank and transport pipe is to be completely discharged, it must be compressed in a closed pressure tank. I am trying to introduce air. This pneumatic transport is used to discharge the remaining particulate material to the outside, but a large amount of compressed air must be consumed.

[Problem that the invention seeks to solve]

The present invention has been made in view of the above problems, and an object of the present invention is to provide a pneumatic transport device that can reduce the amount of compressed air used to empty the inside of a closed pressure tank and transport pipe.

[Means for solving problems]

The above object consists of a closed pressure tank and a transport pipe connected to the tank, and the granular material discharged from the closed pressure tank is transferred to the transport pipe by supplying compressed air in pulses to the transport pipe. In the pneumatic transport device, compressed air is introduced into the sealed pressure tank when the sealed pressure tank and the transport pipe are emptied, wherein the sealed pressure tank has at least its exhaust gas. The pipe for introducing the compressed air for emptying, which has an inverted conical shape at the lower part connected to the outlet part, is arranged so that its open end inside the sealed pressure tank runs along the inner wall surface of the sealed pressure tank. This is achieved by a pneumatic transport device, characterized in that it is fixed to the closed pressure tank.

[Effect]

When emptying the sealed pressure tank and the transport pipe, compressed air is introduced along the inner wall surface of the sealed pressure tank, and the lower part of the sealed pressure tank has an inverted conical shape. As it approaches the bottom of the tank, it is gradually accelerated and ejected into the transport pipe. Therefore, it is possible to increase the wind speed in the transport pipe with a smaller amount of air than in the past, and as a result, the amount of air required to empty the pipe can be greatly reduced.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, a pneumatic transportation device according to an embodiment of the present invention will be described with reference to the drawings.

In the figure, a pressure tank 1 consists of a main body 2 and a lid 3, and the opening of the main body 2 is hermetically covered by the lid 3. A duct 4 is integrally formed with the lid 3 and is connected to the discharge opening of the hopper 9 via a lower valve 5, an intermediate duct 6, an upper valve 7 and a flexible joint 8. The hopper 9 is supported on the ground via appropriate members.

A discharge port 10 formed at the lower part of the main body 2 of the pressure tank 1 is connected to a discharge duct 11, which is connected to an air knife device 12 and a flexible joint 1.
3 to a long transport pipe 14. The transport pipe 14 is rigid rather than flexible, but extends to the collection tank 17, and in place supports 15, 1
It is supported on the ground by 6. Collection tank 17
An air filter 18 is provided at the upper part of the air filter 18, and a valve 19 is provided at the discharge opening, and the valve 19 is opened and closed by an actuating device 20.

As is clear from FIGS. 1 and 2, the pressure tank 1 has an inverted conical lower portion 2a connected to the discharge port 10, and is supported on the ground by a hinge 21 on one side wall thereof. Load cell 2 on the side wall side
2 and is supported on the ground. That is, the entire weight of the pressure tank 1 is measured by the load cell 22. The pressure tank 1 is suspended from the ground by flexible joints 8 and 13, and its total weight is distributed by the valves 5 and 7, the duct 4,
6, 11, and the air knife device 12 is weighed by a load cell 22. Since the weights of these and the main body 2 and lid 3 of the pressure tank 1 are known in advance, the weight of the granular material in the pressure tank 1 can be known from the output of the load cell 22. Furthermore, a vibrator 23 is attached to the side wall of the pressure tank 1, and due to this vibration, even if the granular material does not form a bridge within the pressure tank 1, this is broken, and the inside is always in a good fluid state. It has become possible to hold the

Next, the piping system to the pressure tank 1 will be explained.

A pipe 25 is connected to the tank 24 as a source of compressed air.
Compressed air is supplied to the upper part of the pressure tank 1 via. A valve 28 is connected to the pipe 25, whereby the pressure supplied into the pressure tank 1 is adjusted to, for example, 0.5 to 0.6 atmospheres in gauge pressure. The air flow rate is approximately 5 m/sec. For this purpose, pipe 25
Further, a flow meter 26 and a pressure gauge 27 are connected to. Compressed air supplied from the pipe 25 to the upper part of the pressure tank 1 presses the powder material in the pressure tank 1 downward as a whole.

Pipes 29, 32, and 36 further branch from the pipe 25, and a solenoid valve 30 is connected to the pipe 29 according to the present invention, from which compressed air is also supplied to the upper part of the pressure tank 1. However, during normal pneumatic transportation, that is, pressure tank 1
When the granular material is present at a level above the lower limit level, the electromagnetic valve 30 is closed, and the above-mentioned valve 2
8 is open. In order to empty the pressure tank 1 and to completely discharge the granular material from the conveying pipe 14, the solenoid valve 30 is opened, the above-mentioned valve 28 is closed and a higher pressure is applied, for example 15
Compressed air is sent into the pressure tank 1 at a flow rate of ~20 m/sec.

Furthermore, according to the present invention, the piping 29 is fixed to the tank 1 so that the open end 29a inside the tank 1 is along the inner wall surface 1a of the tank 1, as shown in FIG. Therefore, the compressed air blown out from here hits the inner wall surface 1a as shown by the arrow.
It will be introduced in line with the

The branch pipe 32 is connected to the outlet section 10 of the pressure tank 1 via a valve 35. The compressed air blown in from this fluidizes the powder material present in the pressure tank 1, making it easy to discharge into the transport pipe 14. A flow meter 33 and a pressure gauge 34 are used to adjust the flow rate and pressure of the compressed air so that it is appropriately fluidized.

The branch pipe 36 has a valve 39 and a solenoid valve 40.
It is connected to the air knife device 12 via.
As is well known, the air knife device 12 functions to blow out compressed air from a narrow gap on the outer periphery of the tube to cut the powder material in this area with a knife. The electromagnetic valve 40 automatically repeats on and off to supply pulsed compressed air. Flow meter 37, pressure gauge 38
The pressure and flow rate of this compressed air are adjusted as appropriate.

The solenoid parts 44, 45, 31, 41 of the electromagnetic valves 5, 7, 30, 40 are connected to a control circuit 43, respectively.
is connected to the output terminal of Also load cell 2
The output terminal of No. 2 is connected to the input terminal of the control circuit 43.

A pressure gauge 42 is connected to the tank 24 to detect the pressure inside the tank 24, and compressed air is supplied to it from a compressor (not shown) so that the pressure is within a predetermined range. It is assumed that

The present embodiment is configured as described above, and its operation will be explained next.

First, normal transportation conditions will be explained. Inside the pressure tank 1, granular material of a lower limit level or higher is stored. This is detected by the load cell 22. That is, the specific gravity of the granular material is measured in advance, and the material level is calculated within the control circuit 43 from this value and the detected material weight. From this result, it is determined that the granular material exists in the pressure tank 1 at a level higher than the lower limit level, and the solenoid parts 44, 45, 31
is not excited, but a pulsed current is passed through the solenoid section 41 of the electromagnetic valve 40. That is, the electromagnetic valve 40 repeatedly opens and closes to supply pulsed compressed air to the air knife device 12.

On the other hand, compressed air is supplied to the upper part of the pressure tank 1 through a pipe 25 and a valve 28, and the granular material present in the pressure tank 1 is entirely pressed downward. On the other hand, compressed air is also supplied from the discharge port 10 to keep the powder material in a fluid state. The vibration of the vibrator 23 prevents the formation of bridges of the powdered material in the pressure tank 1, and provides a good and uniform flow state of the material.
The tendency for material to adhere to the inner walls of the pressure tank 1 and create bridging is prevented.

From the pressure tank 1, the granular material is smoothly guided through the duct 11 into the air knife device 12. Here, the continuously supplied powder material is divided by intermittent compressed air as if it were cut with a knife.
As shown in the figure, it is transported in the transport pipe 14 in the form of a plug. 47 is a powder material, and 48 is air.

Particulate material is collected in the collection tank 17, and air is exhausted to the outside through a filter 18. The filter 18 prevents the powder material from leaking to the outside.

When the load cell 22 detects that the granular material in the pressure tank 1 has decreased and reached a predetermined lower limit level, the control circuit 43 generates a signal to alternately energize the solenoids 45 and 44 of the electromagnetic valves 5 and 7. .

That is, the upper electromagnetic valve 7 is opened and the powder material is discharged from the hopper 9 into the duct 6.
When a predetermined amount is discharged or for a predetermined time,
When discharged, the solenoid section 44 is demagnetized and the electromagnetic valve 7 is closed. Next, the solenoid portion 45 of the electromagnetic valve 5 is energized and opened, and the powder material in the duct 6 is discharged into the pressure tank 1. When the gas is discharged for a predetermined period of time or when the duct 6 becomes empty, the solenoid section 45 is demagnetized and the electromagnetic valve 5 is closed. Next, the upper electromagnetic valve 7 is opened by the excitation of the solenoid section 44, and the material is supplied from the hopper 9 into the duct 6.

As described above, the electromagnetic valves 5 and 7 are alternately opened and closed, and the granular material is replenished from the hopper 9 into the pressure tank 1 via the intermediate duct 6. Even during this replenishment, the pressure tank 1 is continuously connected to the transport pipe 14.
The material is supplied to the plug and transported by pulsed compressed air. Compressed air is continuously supplied to the upper part of the pressure tank 1 from a pipe 25.
By alternately opening and closing the electromagnetic valves 5 and 7 as described above, this compressed air is prevented from being exhausted from the hopper 9 into the atmosphere as much as possible. In other words, pressure loss during replenishment is prevented as much as possible.

When the load cell 22 detects that the granular material in the pressure tank 1 has been supplied to a predetermined upper limit level, the alternate excitation of the electromagnetic valves 5 and 7 is stopped.
Both valves 5 and 7 are closed again.

Next, a case where the pressure tank 1 is emptied and the granular material is completely discharged from the transport pipe 14 will be explained.

In this case, a complete ejection button provided in the control circuit 43 is pressed even though it is not shown. Even if the load cell 22 detects that the granular material in the pressure tank 1 has reached the lower limit level, in this case, the electromagnetic valves 5 and 7 will not operate, and the solenoid parts 31 and 41 of the electromagnetic valves 30 and 40 will Energized and demagnetized. That is, the electromagnetic valve 30 opens and compressed air at a high pressure and flow rate is introduced into the pressure tank 1. Further, the electromagnetic valve 40 is normally closed and the supply of pulsed compressed air is stopped.

The material in the pressure tank 1 is discharged into the transport pipe 14 by continuous high-pressure compressed air, and the material in the transport pipe 14 is discharged by the compressed air into the collection tank 17. Note that due to the vibration of the vibrator 23, the amount of material adhering to the inner wall of the pressure tank 1 is reduced as much as possible.

The granular material accumulated in the collecting tank 17 is supplied to the next process by opening the valve 19 by driving the actuating device 20.

The embodiments of the present invention perform the functions described above, and particularly have the following effects.

That is, the powdered material remaining in the pressure tank 1 is transferred to the transport pipe 14 by the compressed air from the pipe 29.
At this time, the compressed air from the pipe 29 is discharged to the pressure tank 1 as shown in FIG.
is introduced along the inner wall surface 1a. pressure tank 1
Since its lower part has an inverted conical shape, the inner wall surface 1
The airflow traveling through a is accelerated as it moves towards the outlet section 10. This accelerated compressed air flow discharges the remaining particulate material into the transport pipe 14,
This tube 14 is transported. The air velocity inside the pipe is much higher than before. As a result, the remaining particulate material in the pressure tank 1 and the transport pipe 14 can be completely discharged to the collection tank 17 with a much smaller amount of compressed air than in the past.

The embodiments of the present invention have been described above, but of course the present invention is not limited thereto, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiment, the total weight of the pressure tank 1 is detected by the load cell 22, and each valve is controlled by this detection signal, but the present invention can also be applied to a pneumatic transport device that does not perform such control. It is.

Further, in the above embodiment, the piping 29 is connected to the pressure tank 1.
Although it is installed relatively above, it may be installed further below.

〔Effect of the invention〕

As described above, according to the pneumatic transport device of the present invention, the amount of compressed air for emptying the granular material in the closed pressure tank and the transport pipe can be further reduced compared to the conventional method.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of a pneumatic conveying device according to an embodiment of the present invention, and FIG.
FIG. 3 is an enlarged cross-sectional view in the linear direction. In the figure, 1...pressure tank, 14...
Transport pipe, 29... Piping, 29a... Open end.

Claims (1)

[Claims] 1 Consisting of a closed pressure tank and a transport pipe connected to the tank, the granular material discharged from the closed pressure tank is plugged along the transport pipe by supplying compressed air in pulses to the transport pipe. In the pneumatic transport device, compressed air is introduced into the sealed pressure tank when the sealed pressure tank and the transport pipe are emptied. The piping, which has an inverted conical shape at its connecting lower part and which introduces the compressed air for emptying, is connected to the sealed pressure tank so that its open end inside the sealed pressure tank is along the inner wall surface of the sealed pressure tank. A pneumatic transport device characterized in that it is fixed to a pressure tank.