JP7371883B2 - Powder transfer device, powder transfer method, and control program - Google Patents

Description

The present invention relates to a powder transfer device, a powder transfer method, and a control program.

BACKGROUND ART As disclosed in Patent Document 1, a powder transport device that transports powder using air flow is known. This powder transfer device uses a double tube consisting of a hollow outer tube and a hollow inner tube that is inserted into the outer tube with a gap between the outer tube and the inner surface of the outer tube. Be prepared. The tip of the double tube is placed at a position facing the powder.

Air is blown into the external flow path defined by the gap between the outer tube and the inner tube, and air is sucked into the inner flow path defined by the inner tube. As a result, the air blown into the external flow path is applied to the powder from the tip of the double tube, and the powder and the air to which the air is applied are transferred from the tip of the double tube to the internal flow path. It gets sucked in. The powder and granules sucked into the internal flow path are transported to a destination by air.

Utility Model Publication No. 04-56130

In the above-mentioned powder or granular material transfer device, if the density of the powder or granular material flowing through the internal channel is too high, blockage or pulsating flow may occur in the internal channel. On the other hand, if the density of the granular material flowing through the internal channel is too low, blockage and pulsating flow are less likely to occur, but the granular material cannot be efficiently transferred.

The object of the present invention is to provide a powder and granule transfer device, a powder and granule transfer method, and a control method that can efficiently transfer powder and granules and prevent clogging or pulsation in flow paths for transferring the powder and granules. The goal is to provide programs.

The powder and granular material transfer device according to the present invention includes:
It has a double tube composed of a hollow outer tube and a hollow inner tube that is inserted into the outer tube with a gap secured between the inner surface of the outer tube, a nozzle member in which the tip of the tube is located at a position facing the powder or granular material to be transferred;
Blowing the transfer gas into one of the internal flow path formed by the inner tube and the external flow path formed by the gap between the outer tube and the inner tube , and the other one. A gas flow forming device that sucks in the transfer gas from a flow path, the gas flow forming device blowing in the transfer gas using a blowing blower ;
a density measuring device that measures the density of the powder and granular material flowing together with the transfer gas in the other channel or a location communicating with the other channel;
When the density measured by the density measuring device is smaller than a predetermined lower limit value, the flow rate of the transfer gas blown into the one flow path by the blowing blower is reduced, and the density measuring device If the density measured by a control device for controlling;
Equipped with

The density measuring device includes:
a camera that photographs the powder and granular material flowing together with the transfer gas in the other channel or a location communicating with the other channel;
an image analysis unit that calculates the density of the powder or granular material by analyzing an image taken and obtained by the camera;
It may have.

the gas flow forming device injects the transfer gas into the external flow path and sucks the transfer gas from the internal flow path;
When the cross-sectional area of the internal flow path perpendicular to the flow of the transfer gas is A, and the cross-sectional area of the external flow path perpendicular to the flow of the transfer gas is B, a cross-sectional area defined as B/A. The ratio may exceed 0.6.
The nozzle member is
A granular material supply regulator formed in a cylindrical shape surrounding the outer surface of the outer tube of the double tube, and having a front end facing the granular material and a rear end opposite to the leading end open. ,
It may have.

The method for transferring powder or granular material according to the present invention includes:
It has a double tube composed of a hollow outer tube and a hollow inner tube that is inserted into the outer tube with a gap secured between the inner surface of the outer tube, a nozzle member in which the tip of the tube is located at a position facing the powder or granular material to be transferred;
A method for transporting powder or granular material using
Blowing the transfer gas into one of the internal flow path formed by the inner tube and the external flow path formed by the gap between the outer tube and the inner tube, and the flow into the other flow path. a starting step of starting the suction of the transfer gas from a passage, the starting step of blowing the transfer gas by a blower ;
In the other flow path or a location communicating with the other flow path, the density of the powder and granular material flowing together with the transfer gas is measured, and if the measured density is smaller than a predetermined lower limit value, , the flow rate of the transfer gas blown into the one flow path is reduced by the blowing blower , and when the measured density is larger than a predetermined upper limit value, the flow rate of the transfer gas blown into the one flow path is reduced. a blowing gas flow rate control step of increasing the flow rate of transfer gas to the blowing blower ;
including.

The control program according to the present invention includes:
It has a double tube composed of a hollow outer tube and a hollow inner tube that is inserted into the outer tube with a gap secured between the inner surface of the outer tube, a nozzle member in which the tip of the tube is located at a position facing the powder or granular material to be transferred;
Blowing the transfer gas into one of the internal flow path formed by the inner tube and the external flow path formed by the gap between the outer tube and the inner tube , and the other one. A gas flow forming device that sucks in the transfer gas from a flow path, the gas flow forming device blowing in the transfer gas using a blowing blower ;
a density measuring device that measures the density of the powder and granular material flowing together with the transfer gas in the other channel or a location communicating with the other channel;
A computer that controls the gas flow forming device in a powder or granular material transfer device comprising:
When the density measured by the density measuring device is smaller than a predetermined lower limit value, the flow rate of the transfer gas blown into the one flow path by the blowing blower is reduced, and the density measuring device If the density measured by control function to control,
Make it happen.

According to the present invention, when the density of the powder or granular material at the other flow path or at a location communicating with the other flow path is smaller than a predetermined lower limit value, the transfer gas blown into one flow path is Flow rate decreases. Accordingly, the amount of transfer gas blown out from one flow path and sucked into the other flow path also decreases, so that the density of the powder and granular material flowing through the other flow path is increased. As a result, the powder or granular material can be transferred efficiently.

On the other hand, if the density of the powder or granular material in the other flow path or at a location communicating with the other flow path is greater than a predetermined upper limit, the flow rate of the transfer gas blown into one flow path increases. do. Along with this, the amount of transfer gas blown out from one flow path and sucked into the other flow path also increases, so that the density of the powder and granular material flowing through the other flow path is reduced. For this reason, blockage or pulsating flow is less likely to occur in the other channel, which is the channel for transferring the powder or granular material.

FIG. 1 is a conceptual diagram showing the configuration of a powder transfer device according to an embodiment. FIG. 1 is a cross-sectional view showing the configuration of a nozzle member according to an embodiment. FIG. 1 is a conceptual diagram showing the configuration of a density measuring device according to an embodiment. 5 is a flowchart of transfer control according to the embodiment. A graph showing the relationship between nozzle efficiency and flow rate ratio.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A powder transfer device according to an embodiment will be described below with reference to the drawings. In the figures, the same or corresponding parts are denoted by the same reference numerals.

As shown in FIG. 1, the powder or granule transfer device 700 according to this embodiment transfers the powder or granule PM contained in a container 610 to a recovery tank 620. Air is used as a transfer gas to transfer the powder PM.

The powder transfer device 700 includes a nozzle member 100 that sucks powder PM together with air from a container 610, and a cyclone separator that separates the powder PM from the powder PM and air sucked through the nozzle member 100. 630, and a hopper 640 that guides the powder PM separated by the cyclone separator 630 to the recovery tank 620.

The powder transfer device 700 also includes a suction blower 210 that forms an air flow for sucking powder PM and air from the nozzle member 100, and a blower blower 210 that forms an air flow for blowing out air from the nozzle member 100. A blower 220 is provided. The suction blower 210 is connected to the cyclone separator 630, and the blowout blower 220 is connected to the nozzle member 100.

The powder transfer device 700 also includes a suction valve 651 disposed in an air flow path between the suction blower 210 and the cyclone separator 630, and an air flow between the blow-off blower 220 and the nozzle member 100. A blow-off valve 652 arranged in the flow path is provided. Each of the suction valve 651 and the blowout valve 652 can be switched between an open state that allows air flow and a closed state that blocks air flow.

The configuration and operation of the nozzle member 100 will be described with reference to FIG. 2. As shown in FIG. 2, the nozzle member 100 has a double pipe 130. The double tube 130 includes a hollow outer tube 110 and a hollow inner tube 120 inserted into the outer tube 110 with a gap GP secured between the inner surface of the outer tube 110 and the inner surface of the outer tube 110 .

Each of the outer tube 110 and the inner tube 120 has a circular cross section perpendicular to the length direction. The double pipe 130 extends in the vertical direction, and the tip, specifically the lower end, of the double pipe 130 is disposed at a position facing the powder PM.

The blower 220 blows air, which is a transfer gas, into the external flow path OP defined by the gap GP between the outer tube 110 and the inner tube 120. The suction blower 210 sucks air, which is a transfer gas, from the internal flow path IF formed by the inner tube 120 via the cyclone separator 630 shown in FIG.

The suction blower 210 and the blowout blower 220 are an example of a gas flow forming device that blows the transfer gas into one of the internal flow path IF and the external flow path OF, and sucks the transfer gas from the other flow path. .

According to the above configuration, the air blown into the external flow path OF is applied to the powder PM from the tip of the double pipe 130. The air-irradiated powder PM and the air are sucked into the internal flow path IF from the tip of the double pipe 130. The jetting of air from the external flow path OF to the granular material PM promotes the suction of the granular material PM and air into the internal flow path IF. Therefore, the efficiency of transporting the powder PM can be increased.

The powder PM and air sucked into the internal flow path IF flow into the cyclone separator 630 shown in FIG. 1, where the powder PM and air are separated. Then, the powder PM flows down to the recovery tank 620 shown in FIG. 1, while the air is discharged to the outside by the suction blower 210.

The nozzle member 100 also includes a powder supply regulator 140 that adjusts the supply of powder PM to the tip of the double pipe 130. The powder supply regulator 140 is formed into a cylindrical shape that surrounds the outer surface of the outer tube 110 concentrically with the double tube 130, and extends in the vertical direction like the double tube 130. The tip of the powder supply regulator 140 facing the powder PM is open. Further, the rear end of the powder supply regulator 140 opposite to the front end is also open to allow air to circulate.

The tip of the powder supply regulator 140 is located above the tip of the double pipe 130. That is, the double pipe 130 protrudes below the powder supply regulator 140. The position of the tip of the powder supply regulator 140 is such that the line segment connecting the tip of the powder supply regulator 140 and the tip of the double pipe 130 is such that the tip of the powder PM is in a horizontal plane. It is adjusted so that it is tilted by an angle θ equal to the angle of repose.

In addition, in the double pipe 130, the inner pipe 120 projects further downward than the outer pipe 110. The line segment connecting the tip of the outer tube 110 and the tip of the inner tube 120 is also inclined at an angle θ with respect to the horizontal plane.

As described above, the powder supply regulator 140 and the outer tube 110 form an inclination of the angle θ equal to the angle of repose on the powder PM. As a result, the powder PM flows toward the inner tube 120 along the angle of repose due to gravity. Therefore, the powder PM is continuously supplied toward the tip of the inner tube 120, and the efficiency of transferring the powder PM can be improved.

Returning to FIG. 1, the explanation will be continued. The powder transfer device 700 includes a flow rate measuring device 300 that measures the flow rate of air sucked in by the suction blower 210 (hereinafter referred to as the suction air flow rate). The flow rate measuring device 300 is arranged in an air flow path between the cyclone separator 630 and the suction blower 210.

If the flow path from the tip of the nozzle member 100 to the cyclone separator 630 is clogged with particulate matter PM, even if the suction blower 210 is operating, the flow rate of the suction air sucked by the suction blower 210 will be significantly reduced. descend. Therefore, based on the value of the intake air flow rate measured by the flow rate measuring device 300, it is possible to detect whether or not clogging of the powder PM has occurred.

Further, the granular material transfer device 700 includes a density measuring device 400 that measures the density of the granular material PM flowing together with air at a location communicating with the internal flow path IF shown in FIG. The density measuring device 400 is disposed beside a flow path from the nozzle member 100 to the cyclone separator 630, specifically, a connecting pipe 660 that connects the internal flow path IF shown in FIG. 2 and the cyclone separator 630. There is.

As shown in FIG. 3, the density measuring device 400 includes a camera 410 having an image sensor, and an image analysis unit 420 that analyzes an image taken by the camera 410. A part of the connecting tube 660 is constituted by a transparent member 661 that is transparent to the light captured by the image sensor of the camera 410, specifically, to visible light.

The camera 410 photographs the powder PM flowing through the connecting pipe 660 together with the air through the transparent member 661. Photographing by the camera 410 is repeatedly performed at a predetermined sampling frequency. The image analysis unit 420 obtains a physical quantity representing the density of the powder PM, specifically, the number of particles per unit volume, by analyzing an image taken and obtained by a camera. Note that the image analysis performed by the image analysis unit 420 includes digital image processing such as processing for determining image density, binarization, and background subtraction.

Returning to FIG. 1, the explanation will be continued. The powder transfer device 700 controls a suction blower 210, a suction valve 651, a blow-off blower 220, and a blow-off valve 652 in order to transfer the powder PM from the container 610 to the recovery tank 620. It includes a control device 500 that performs control.

In the transfer control, the control device 500 controls the rotation speed of the blowing blower 220 using the measurement results of the flow rate measuring device 300 and the density measuring device 400 while keeping the rotation speed of the suction blower 210 constant.

Control device 500 stores a control program 510. The transfer control achieved by the control device 500 executing the control program 510 will be specifically described below.

As shown in FIG. 4, first, the control device 500 opens the suction valve 651 and the blow-off valve 652 in response to a user's instruction to start transferring the powder PM, and opens the suction blower 210 and the blow-off valve 652. The operation of the blower 220 is started (step S11).

As a result, the air blown into the external flow path OF by the blowing blower 220 is applied to the powder PM from the tip of the double pipe 130, and the powder PM and the air to which the air is applied are It is sucked into the internal flow path IF from the tip of the heavy pipe 130.

The granular material PM and air sucked into the internal flow path IF flow into the cyclone separator 630, where the granular material PM and air are separated. The powder PM flows down into the recovery tank 620, while the air is discharged to the outside by the suction blower 210. In this way, the transfer of the powder PM starts. In other words, step S11 is an example of a starting step for starting the transfer of the particulate material PM.

Next, the control device 500 waits for a certain period of time that is predetermined as the time required for the flow of the powder PM to become steady (step S12).

Next, the control device 500 determines that the density of the powder PM measured by the density measuring device 400 is equal to or higher than a predetermined lower limit value to ensure efficient transfer, and that blockage and pulsation are prevented. It is determined whether or not it is below a predetermined upper limit value for suppression (step S13).

If the density of the granular material PM is smaller than the lower limit value in step S13 (step S13; density of the granular material<lower limit value), the control device 500 maintains the rotation speed of the suction blower 210 constant, By lowering the rotational speed of the blowing fan 220, the amount of air blown into the external flow path OF by the blowing fan 220 (hereinafter referred to as the blowing air flow rate) is reduced (step S14).

As a result, the amount of air blown out from the external flow path OF and sucked into the internal flow path IF is also reduced, so that the density of the powder PM flowing through the internal flow path IF is increased. As a result, the powder PM can be efficiently transferred.

On the other hand, if the density of the powder PM is larger than the upper limit in step S13 (step S13; density of powder > upper limit), the control device 500 maintains the rotation speed of the suction blower 210 constant. By increasing the rotational speed of the blower 220, the flow rate of air blown into the external flow path OF by the blower 220 is increased (step S15).

As a result, the amount of air blown out from the external flow path OF and sucked into the internal flow path IF also increases, so that the density of the powder PM flowing through the internal flow path IF is reduced. Therefore, blockage or pulsating flow is unlikely to occur in the flow path of the powder PM from the nozzle member 100 to the recovery tank 620, including the internal flow path IF.

Note that Step S14 and Step S15 described above are an example of a blowing gas flow rate control step that controls the flow rate of the transfer gas blowing into the external flow path OF.

On the other hand, if the density of the powder PM is greater than or equal to the lower limit value and less than or equal to the upper limit value in step S13 (step S13; YES), or after passing through step S14 or step S15, the control device 500 controls the flow rate measuring device 300 to It is determined whether the measured flow rate of suction air sucked by the suction blower 210 is equal to or greater than a threshold value indicating that air is flowing normally (step S16).

If the intake air flow rate is less than the threshold value in step S16 (step S16; NO), the control device 500 indicates that the flow path from the tip of the nozzle member 100 to the cyclone separator 630 is clogged with powder PM. Therefore, transfer control is ended. In this case, the transfer control can be restarted after the user removes the blockage of the powder PM.

If the suction air flow rate is equal to or higher than the threshold value in step S16 (step S16; YES), the control device 500 determines that the powder PM is flowing normally in the flow path from the tip of the nozzle member 100 to the cyclone separator 630. Therefore, it is determined whether there is an instruction from the user to end the transfer of the powder or granular material PM (step S17).

Then, if the control device 500 has not finished transferring the powder or granular material PM yet (step S17; NO), the control device 500 returns to step S13. On the other hand, if the control device 500 receives an instruction from the user to end the transfer of the powder or granular material PM (step S17; YES), the control device 500 ends the transfer control.

Below, the results of an experiment conducted to find the optimal shape for the double pipe 130 will be described.

When the cross-sectional area of the internal flow path IF perpendicular to the air flow is A, and the cross-sectional area of the external flow path OF perpendicular to the air flow is B, the cross-sectional area ratio defined as B/A, In order to examine the relationship between the energy efficiency and the energy efficiency of transporting the powder PM, two types of double pipes 130 according to Examples 1 and 2 were created.

The double pipe 130 according to the first embodiment is composed of an inner pipe 120 with a diameter of 40 [mm] and an outer pipe 110 with a diameter of 50.6 [mm], and the cross-sectional area ratio B/A = 0.6. It is. The double pipe 130 according to the second embodiment is composed of an inner pipe 120 with a diameter of 40 [mm] and an outer pipe 110 with a diameter of 55 [mm], and the cross-sectional area ratio B/A is 0.9. .

Nozzle efficiency was used as an evaluation index representing the energy efficiency of transporting particulate matter PM. Nozzle efficiency is calculated as Defined by Y.

The denominator Y is the first work W1 performed while the suction flow flowing through the internal flow path IF flows from the tip of the inner pipe 120 to the above-mentioned specific height position (hereinafter referred to as the first measurement point); The second work W2 is performed during the process in which the blowout flow flowing through the external flow path OF flows from a position at the same height as the first measurement point (hereinafter referred to as the second measurement point) to the tip of the outer tube 110. It is Japanese.

The first work W1 is determined by multiplying the difference between the pressure at the first measurement point and the atmospheric pressure by the volumetric flow rate Q1 of the suction flow over the period during which the nozzle efficiency is measured (hereinafter simply referred to as the measurement period). . The second work W2 is determined by multiplying the difference between the pressure at the second measurement point and the atmospheric pressure by the volumetric flow rate Q2 of the blowout flow over the measurement period.

The molecule X is determined by multiplying the mass flow rate of the powder PM over the measurement period by the height from the tip of the inner tube 120 to the first measurement point. Note that the nozzle efficiency X/Y refers to an average value over the measurement time.

Nozzle efficiency X/Y represents how much of the energy output by the suction blower 210 and the blowout blower 220 is used for transporting the powder PM. The larger the nozzle efficiency X/Y, the better the energy efficiency. In other words, when the power consumption in the suction blower 210 and the blowout blower 220 are the same, the larger the nozzle efficiency X/Y is, the more powder PM can be transferred.

The nozzle efficiency X/Y explained above was measured under each of a plurality of conditions in which the flow rate ratio Q2/Q1 was varied. The flow rate ratio Q2/Q1 is a value obtained by dividing the volumetric flow rate Q2 over the measurement period of the above-mentioned blowout flow by the volumetric flow rate Q1 over the measurement period of the suction flow described above. The flow rate ratio Q2/Q1 was changed by fixing Q1 and adjusting Q2.

FIG. 5 shows a graph of the measurement results. The horizontal axis shows the flow rate ratio Q2/Q1, and the vertical axis shows the nozzle efficiency X/Y. It can be seen that for any flow rate ratio Q2/Q1, the nozzle efficiency X/Y of Example 2 plotted with square marks is approximately three times greater than that of Example 1 plotted with triangle marks.

In other words, the larger the cross-sectional area ratio B/A, which is the ratio between the cross-sectional area A of the internal flow path IF and the cross-sectional area B of the external flow path OF, is, the higher the energy efficiency is. From the above results, it can be said that the cross-sectional area ratio B/A of the double pipe 130 is preferably greater than 0.6, and more preferably 0.9 or more.

Furthermore, as described above, in adjusting the flow rate ratio Q2/Q1, even though the volumetric flow rate Q1 of the suction flow was fixed, as shown in FIG. Depends on. Specifically, the larger the flow rate ratio Q2/Q1, the smaller the nozzle efficiency X/Y.

This is because the larger the volumetric flow rate Q2 of the blowout flow, the more the powder PM is blown outward in the radial direction of the double pipe 130 by the blowout flow. This is due to the decrease in PM density.

The embodiments of the present invention have been described above. The present invention is not limited to this, and the following modifications are also possible.

In the above embodiment, a configuration is illustrated in which air is sucked in from the internal flow path IF and air is blown into the external flow path OF, but air may be sucked in from the external flow path OF and air may be blown into the internal flow path IF. Further, the transfer gas is not limited to air, and may be an inert gas such as argon, nitrogen, or carbon dioxide.

Further, in the above embodiment, the outer tube 110 and the inner tube 120 constituting the double tube 130 each have a circular cross section, but the outer tube 110 and the inner tube 120 are limited to circular cross sections. I can't do it. The cross sections of the outer tube 110 and the inner tube 120 may be polygonal, such as triangular or quadrangular.

In the above embodiment, although FIG. 2 illustrates a state where the tip of the double tube 130 is separated from the powder PM, the tip of the double tube 130 is inserted into the powder PM. or may be in contact with the powder PM.

Furthermore, in this specification, granular PM refers not only to aggregates of granular substances such as soil, sand, gravel, cement, and flour, but also to aggregates of dust-like substances such as dust, soot, and volcanic ash. It is a concept that includes

Furthermore, by installing the control program 510 shown in FIG. 1 into a computer, the computer can function as the control device 500. The control program 510 can be distributed through a communication line, or can be stored and distributed in a computer-readable recording medium such as an optical disk, a magnetic disk, or a flash memory.

100... nozzle member,
110...outer tube,
120...inner pipe,
130...double pipe,
140... Powder supply regulator,
210...Suction blower (gas flow forming device),
220...Blowing blower (gas flow forming device),
300...Flow rate measuring device,
400...density measuring device,
410...Camera,
420...Image analysis section,
500...control device,
510...control program,
610...container,
620...Recovery tank,
630...Cyclone separator,
640...Hopper,
651...Suction valve,
652...Blowout valve,
660...Connection pipe,
661...Transparent member,
700...Powder transfer device,
GP...Gap,
IF...internal flow path,
OF...external flow path,
PM...Powder material.

Claims (6)

It has a double tube composed of a hollow outer tube and a hollow inner tube that is inserted into the outer tube with a gap secured between the inner surface of the outer tube, a nozzle member in which the tip of the tube is located at a position facing the powder or granular material to be transferred;
Blowing the transfer gas into one of the internal flow path formed by the inner tube and the external flow path formed by the gap between the outer tube and the inner tube , and the other one. A gas flow forming device that sucks in the transfer gas from a flow path, the gas flow forming device blowing in the transfer gas using a blowing blower ;
a density measuring device that measures the density of the powder and granular material flowing together with the transfer gas in the other channel or a location communicating with the other channel;
When the density measured by the density measuring device is smaller than a predetermined lower limit value, the flow rate of the transfer gas blown into the one flow path by the blowing blower is reduced, and the density measuring device If the density measured by a control device for controlling;
A powder and granular material transfer device comprising: The density measuring device includes:
a camera that photographs the powder and granular material flowing together with the transfer gas in the other channel or a location communicating with the other channel;
an image analysis unit that calculates the density of the powder or granular material by analyzing an image taken and obtained by the camera;
The powder transfer device according to claim 1, comprising: the gas flow forming device injects the transfer gas into the external flow path and sucks the transfer gas from the internal flow path;
When the cross-sectional area of the internal flow path perpendicular to the flow of the transfer gas is A, and the cross-sectional area of the external flow path perpendicular to the flow of the transfer gas is B, a cross-sectional area defined as B/A. ratio exceeds 0.6,
The powder transfer device according to claim 1 or 2. The nozzle member is
A granular material supply regulator formed in a cylindrical shape surrounding the outer surface of the outer tube of the double tube, and having a front end facing the granular material and a rear end opposite to the leading end open. ,
The granular material transfer device according to any one of claims 1 to 3, which has the following. It has a double tube composed of a hollow outer tube and a hollow inner tube that is inserted into the outer tube with a gap secured between the inner surface of the outer tube, a nozzle member in which the tip of the tube is located at a position facing the powder or granular material to be transferred;
A method for transporting powder or granular material using
Blowing the transfer gas into one of the internal flow path formed by the inner tube and the external flow path formed by the gap between the outer tube and the inner tube, and the flow into the other flow path. a starting step of starting the suction of the transfer gas from a passage, the starting step of blowing the transfer gas by a blower ;
In the other flow path or a location communicating with the other flow path, the density of the powder and granular material flowing together with the transfer gas is measured, and if the measured density is smaller than a predetermined lower limit value, , the flow rate of the transfer gas blown into the one flow path is reduced by the blowing blower , and when the measured density is larger than a predetermined upper limit value, the flow rate of the transfer gas blown into the one flow path is reduced. a blowing gas flow rate control step of increasing the flow rate of transfer gas to the blowing blower ;
A method for transferring powder and granular materials, including It has a double tube composed of a hollow outer tube and a hollow inner tube that is inserted into the outer tube with a gap secured between the inner surface of the outer tube, a nozzle member in which the tip of the tube is located at a position facing the powder or granular material to be transferred;
Blowing the transfer gas into one of the internal flow path formed by the inner tube and the external flow path formed by the gap between the outer tube and the inner tube , and the other one. A gas flow forming device that sucks in the transfer gas from a flow path, the gas flow forming device blowing in the transfer gas using a blowing blower ;
a density measuring device that measures the density of the powder and granular material flowing together with the transfer gas in the other channel or a location communicating with the other channel;
A computer that controls the gas flow forming device in a powder or granular material transfer device comprising:
When the density measured by the density measuring device is smaller than a predetermined lower limit value, the flow rate of the transfer gas blown into the one flow path by the blowing blower is reduced, and the density measuring device If the density measured by control function to control,
A control program that realizes this.