JPH07113567B2 - Measuring device for powder and granular material - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a powdery or granular material weighing device having a function of preventing the powdery or granular material from being scattered at the time of charging the powdery or granular material into a weighing hopper.

<Prior Art> In the case of performing quantitative cutout of powder or granules, a weighing device for measuring the weight of the powder or granules is used in order to ensure the quantitativeness of the cutout amount.

Conventionally, as shown in FIG. 3 and FIG. 4, a powdery or granular material weighing device 1 ′ has a loading hopper 2 for storing the powdery or granular material 20 and a weighing hopper 5 located below the loading hopper 2. The structure is such that the powder and granular material discharge port 3 of the hopper 2 and the powder and granular material input port 6 of the weighing hopper 5 are connected via a filter cloth material 23. The weighing device 1'shown in FIG. 3 is configured so that the powder hopper 20 is naturally fed to the weighing hopper 5 through the filter 25 by the deaeration port 24 into which the powder 20 is put.
It is designed to remove air inside the
The metering device 1'shown in the figure has a degassing pipe 26 and a fan (not shown) connected to the degassing port 24 through a filter cloth material 23 '.
It has a function of forcibly deflating the air in the weighing hopper 5 by a suction mechanism composed of the above.

By the way, when measuring the granular material, the measuring and weighing hopper 5 containing the granular material 20 is placed on the measuring device 9 such as the load cells 91, 91.
Since the vertical movement amount of the weighing hopper 5 is digitized,
The discharge port 3 of the charging hopper 2 and the charging port 6 of the weighing hopper 5 cannot be directly connected. Therefore, these are lightweight, flexible, stretchable filter cloth materials that have little effect on the measured value.
Connected through 23.

Further, the filter cloth material 23 has a property of allowing air to pass through but not allowing the powder or granular material 20 to pass therethrough from the viewpoint of preventing leakage (scattering) of the powder or granular material 20.

However, when such a conventional weighing device 1'is used for a long time, the powder particles 20 adhere to the filter cloth material 23 and cause clogging. Therefore, the weight of the adhered powder particles is added to the measured value. And causes a measurement error.

In the case of the conventional apparatus shown in FIG. 4, the suction mechanism brings the pressure hopper 5 into a depressurized state, but especially when the filter cloth materials 23, 23 'are clogged. It becomes difficult for air to pass through ′, which may adversely affect the measured value.

The above-described weighing error is caused by the small capacity of the weighing hopper 5, and when weighing a small amount of the granular material 20 (for example, gram order weighing), it is highly accurate due to the nature of the granular material 20 such as chemicals. When measurement is required, it is too large to ignore.

<Problems to be Solved by the Invention> An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide a powdery or granular material measuring device capable of measuring powdery or granular material with higher accuracy. It is in.

<Means for Solving Problems> In order to achieve such an object, the inventors of the present invention have as a result of earnest research, and as a result, have established a powder and granular material discharge port of a charging hopper and a powder and granular material charging port of a weighing hopper. It is non-contact, and when measuring, the influence of the filter cloth material that is these connecting members does not affect the measured value, and at the time of charging the powder or granular material, the entire outer circumference between the discharge port and the charging port is set. The present invention has been found to prevent leakage of powder and granules by forming and sealing an air curtain.

That is, the present invention, the powder and granules are stored, a charging hopper having a discharge port for discharging the powder and granules in the lower portion, and a charging port for the powder and granules that are installed facing each other at the discharge port above In a weighing hopper having a weighing hopper and a weighing means for weighing the weight of the powder or granular material put into the weighing hopper, wherein the discharge port of the input hopper and the input port of the weighing hopper are all It is installed in either one of the circumference and has an annular air ejection port that ejects air in a cylindrical shape, and the other is installed facing the air ejection nozzle and ejects in the cylindrical shape. An air suction member having an annular air suction port for sucking the compressed air in a cylindrical shape, and an air supply means for jetting and sucking air from the air jet port and the air suction port,
And, the charging port of the weighing hopper is in non-contact with both the air ejection nozzle and the air suction member, and when the powder or granular material is charged into the measuring hopper, the end face of the discharge port is operated by the operation of the air supply means. The present invention provides a powdery or granular material measuring device, characterized in that a cylindrical air curtain is formed over the entire circumference of a gap between the end face of the charging port and the end face.

Further, in the powdery or granular material measuring device, the air supply means includes an air supply source for sending out compressed air, a supply pipe connecting the air supply source and the air ejection nozzle, and an air suction member inside the member. An ejector that generates a negative pressure, an intake pipe that connects the ejector and the air intake member, and a branch from the supply pipe that is connected to the ejector, forms a high-speed air flow in the ejector, and forms a negative pressure. It is preferable to have a branch pipe for generating

Further, it is preferable that the air curtain is formed by the air supply means only when the powdery particles are put into the weighing hopper from the inputting hopper.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a preferred embodiment of the powdery or granular material measuring device of the present invention shown in the accompanying drawings will be described in detail.

FIG. 1 is a partial side sectional view schematically showing a configuration example of the powdery or granular material weighing device 1 of the present invention. As shown in the figure, a powder and granular material weighing device 1 includes a charging hopper 2 in which the powder and granular materials 20 are stored, and a weighing hopper 5 below the input hopper 2 for weighing the powder and granular materials 20.
Have and.

The discharge port 3 for the powder or granules 20 is formed in the lower part of the charging hopper 2, and the powder or granules in the charging hopper 2 are rotated by the rotation of the feeder 4.
20 can be discharged quantitatively.

On the other hand, in the upper part of the weighing hopper 5, there is formed an inlet 6 for the powder or granular material 20 which is installed facing the discharge outlet 3 by a predetermined distance, and the powder or granular material 20 is introduced into the weighing hopper 5 through the inlet 6. It is supposed to be introduced.

The weighing hopper 5 is supported by a weighing device 9 such as the load cells 91, 91, and moves in the vertical direction (the direction of the arrow in the figure) according to the weight added to the weighing device 9, and this moving amount is used as the weight. The weight of the powdery or granular material 20 in the weighing hopper 5 is converted and weighed. The weighing means is not limited to the one described above, and may have any configuration as long as it can weigh the powder particles 20 in the weighing hopper 5.

A screw 7 is installed below the weighing hopper 5, and the screw 7 is rotated in a predetermined direction by driving a driving source 8 such as a motor connected to one end of a shaft 71 of the screw 7, and the side ( The powder particles 20 can be cut out quantitatively in the right direction in FIG.

The feature of the powdery or granular material weighing device 1 of the present invention is that the powdery or granular material 20 is spread over the entire circumference of the gap 21 between the end surface of the discharge port 3 of the input hopper 2 and the end surface of the input port 6 of the weighing hopper 5 when the powdery material 20 is input. It is configured to form the air curtain 22.

The configuration will be described in detail below.

As shown in FIGS. 1 and 2, an air ejection nozzle 10 is loosely fitted around the charging port 6, while the discharging port 3 is provided.
An air suction member 11 is loosely fitted in the. The air jet nozzle 10 has a discharge port 3 over the entire circumference of the input port 6.
An annular air jet 101 is formed that opens in the direction of
On the other hand, the air suction member 11 has an annular air suction port 111 that is open in the direction of the charging port 6 over the entire circumference of the discharging port 3.
Are formed.

The air supplied into the air jet nozzle 10 is jetted from the air jet 101 and is sucked into the air suction port 111 of the air suction member 11. As a result, an air curtain 22 is formed over the entire circumference of the gap 21 between the end face of the charging port 6 and the end face of the discharging port 3, and when the powdered or granular material 20 is charged into the weighing hopper 5, the outer periphery of the gap 21 is sealed, Leakage of the granules 20 can be prevented.

It is preferable that the shapes of the air ejection port 101 and the air suction port 111 correspond to the outer peripheral shapes of the charging port 6 and the discharging port 3. In the example shown in FIG. Since the shape is cylindrical, the air jet 101 and the air suction port 111 are annular. However, the shape of the air ejection port 101 and the air suction port 111 is not limited to this, and may be an annular shape such as a rectangle, a polygon, an ellipse, or the like corresponding to the outer peripheral shapes of the inlet 6 and the outlet 3. .

The air jet nozzle 10 and the air suction member 11
Since the reaction force of the jet air is applied to these, the air jet nozzle 10 and the air suction member 11 are fixed to the inlet 6 and the outlet 3 in consideration of the influence on the measuring device 9. It is preferable that they are not installed but installed independently. Further, the air jet nozzle 10 and the air suction member 11
When the two are connected by a predetermined member (the positional relationship between the nozzle 10 and the member 11 does not change), the air suction member 11 is fixed to the discharge port, and the air ejection nozzle 10 is loosely fitted to the charging port. It is also possible to set. That is, in the present invention, the charging port 6 and the air ejection nozzle (air suction member 11) are not in contact with each other so that the reaction force of the ejection air is not applied to the weighing hopper 5 or the reaction force applied thereto. Nozzle for air ejection so that there is as little as possible
10 and the member 11 for inhaling air are installed.

Further, in the above-described configuration example, the air ejection nozzle 10 is installed on the inlet 6 side (lower side) and the air intake member 11 is installed on the outlet 3 side (upper side), but these may be installed vertically. The air jet nozzle 10 may be installed on the upper side and the air suction port 11 may be installed on the lower side.

The ejection and suction of air from the air ejection port 101 and the air suction port 111 are performed by an air supply unit having the following configuration.

As shown in FIG. 1, the proximal end side of the pipe 14 is connected to an air supply source 12 capable of sending compressed air, and
An electromagnetic valve 13 capable of controlling passage and interruption of air sent from the air supply source 12 is installed in the middle of 14.

On the other hand, the end of pipe 14 branches into pipe 15 and pipe 16,
Is connected to the air discharge nozzle 10.

A base end side of the pipe 17 is connected to the air intake member 11, and an ejector 18 for generating a negative pressure in the air intake member 11 is installed in the middle of the pipe 17. The ejector 18 is composed of, for example, a Venturi pipe, and the end of the pipe 16 branched from the pipe 14 is connected to the ejector 18 to form a high-speed air flow to reduce the pressure, and an air suction member. Negative pressure is generated on the 11 side, and air is forcibly sucked through the air suction port 111.

In this way, the air jetted at high speed from the air jet 101 is handled by the air suction port 111, and the air curtain 22 is formed over the entire circumference of the gap 21.

The formation of the air curtain 22 as described above is performed when the powder particles 20 are charged from the charging hopper 2 to the weighing hopper 5, so that some of the dust particles generated are part of the air inlet 111 along with the air flow.
Is sucked into. Therefore, a filter 19 is installed on the end side of the pipe 17 or the like so that only the air is discharged to the outside so that the powder or granules transferred in the pipe 17 can be collected again.

Note that the present invention is not limited to the air supply means having the above-described configuration, and in particular, without using the pipe 16 and the ejector 18, the inside of the air suction member 11 is provided by using an independent pressure reducing means such as a compressor or a fan. Negative pressure may be generated.

<Operation> The operation of the powdery or granular material measuring device of the present invention will be described below.

As shown in FIG. 1, when the powdered or granular material 20 in the charging hopper 2 is charged into the weighing hopper 5, first, the air supply source 12 is operated, the solenoid valve 13 is opened, and compressed air is supplied. Send to pipe 14. The air passing through the pipe 14 in the direction of the arrow in the figure
The air that has branched to 16 and 16 and has passed through the pipe 15 is sent to the air ejection nozzle 10 and is evenly ejected from the annular air ejection port 101.

On the other hand, the air that has passed through the pipe 16 is ejected into the ejector 18, forms a high-speed air flow in the narrowed portion to reduce the pressure, and is introduced into the air suction member 11 via the pipe 17 on the proximal end side of the ejector 18. Generates pressure and sucks air through the annular air inlet.

In this way, the air ejected from the air ejection port 101 is sucked through the air suction port 111, so that the air curtain 22 is provided over the entire circumference of the gap 21 between the discharge port 3 and the charging port 6.
Are formed to substantially air seal the entire circumference of the gap 21. While the air curtain 22 is being formed, the feeder 4 is rotated so that the powder particles 20 in the charging hopper 2 are discharged from the discharge port 3
Then, it is charged into the weighing hopper 5 through the charging port. Gap 21
Since the air curtain 22 is formed all around, the powder 20 is prevented from leaking to the outside when the powder 20 drops from the discharge port 3 to the charging port 6.

The air jetted from the pipe 16 into the ejector 18 and the air sucked by the air suction member 11 are discharged to the outside via the pipe 17.

It should be noted that although a small amount of dust particles 20 caused by dust generation are also sucked from the suction port 111 of the air suction member 11 at the same time, the particles are collected and collected by the filter 19 installed at the end of the pipe 17. It

When the charging of the powdered or granular material 20 into the weighing hopper 5 is completed, the solenoid valve 13 is operated to shut off the air flow, and the air jet nozzle
Turn off air supply to 10. In this state, the granular material 20 in the weighing hopper 5 is weighed by the weighing device 9.

Unlike the conventional weighing device 1'shown in FIGS. 3 and 4, when weighing, since the discharge port 3 and the charging port 6 of the granular material 20 are not in contact with each other, the filter cloth material 23 or the filter cloth material 23 adheres to this. There is no influence on the measured value of the weight of the powdered or granular material. Further, since the air curtain 22 is not formed at the time of measurement, there is no influence on the measurement value by the reaction force of the jet air.

Therefore, highly accurate measurement is possible.

The screw 7 is rotated in a predetermined direction by the operation of the drive source 8 and the powder particles 20 in the weighing hopper 5 are quantitatively cut laterally. By this quantitative cutout, the powder or granular material 20 in the weighing hopper 5 is
When the amount of is reduced to a certain degree, the granular material 20 is charged again according to the above procedure. The timing of charging the powder or granular material 20 is determined by the measured value of the powder or granular material 20 obtained by the above-mentioned measurement and the quantitative cut-out amount by the screw 7.

<Effects of the Invention> According to the powdery or granular material measuring device of the present invention, the discharge port of the charging hopper and the charging port of the weighing hopper are brought into non-contact with each other, and when the powdery or granular material is charged, the end face of the discharge port and the charging By forming an air curtain around the entire gap between the end faces of the mouth, the leakage of powder to the outside can be effectively stopped at the time of loading the powder, and the conventional discharge port at the time of weighing. It is possible to eliminate the adverse effect on the measured value based on the filter cloth material used for connecting the inlet and the inlet, and perform highly accurate weighing.

[Brief description of drawings]

FIG. 1 is a partial side sectional view schematically showing a configuration example of a powdery or granular material measuring device of the present invention. FIG. 2 is a partial perspective view showing the structure near the discharge port and the charging port of the powdery or granular material measuring device of FIG. FIG. 3 and FIG. 4 are partial side cross-sectional views schematically showing the configuration of a conventional powdery or granular material weighing device. Explanation of reference numerals 1 ... measuring device for powder or granular material, 1 '... conventional measuring device for powder or granular material, 2 ... input hopper, 3 ... discharging port, 4 ... feeder, 5 ... measuring hopper, 6 …… Inlet, 7 …… Screw, 71 …… Shaft, 8 …… Drive source, 9 …… Measuring instrument, 91 …… Load cell, 10 …… Air jet nozzle, 101 …… Air jet, 11 …… Air suction member, 111 …… Air suction port, 12 …… Air supply source, 13 …… Solenoid valve, 14,15,16,17 …… Piping, 18 …… Ejector, 19 …… Filter, 20 …… Powder Granules, 21 …… Gap, 22 …… Air curtain, 23,23 ′ …… Filter cloth material, 24 …… Degassing port, 25 …… Filter, 26 …… Degassing pipe

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masayuki Yasuguchi 5-6-5-707 Kamizuruma, Sagamihara City, Kanagawa Prefecture (56) Reference JP-A-59-173718 (JP, A) JP-A-54-8368 (JP, A)

Claims (3)

[Claims] 1. A charging hopper that stores powder and granules and has a discharge port that discharges the powder and granules at a lower portion thereof, and a charging port for the powder and granules that are installed facing each other at a distance from the discharge port. In a weighing device for powder and granules, which has a weighing hopper and a weighing means for weighing the weight of the powder and granules loaded into the weighing hopper, the discharge port of the loading hopper and the entire circumference of the loading port of the weighing hopper. Installed in either one of them, and has an annular air ejection nozzle for ejecting air in a cylindrical shape, and an air ejection nozzle on the other side that is installed to face the air ejection nozzle and ejects in the cylindrical shape. An air suction member having an annular air suction port for sucking air in a cylindrical shape, and an air supply means for jetting and sucking air from the air jet port and the air suction port,
And, the charging port of the weighing hopper is in non-contact with both the air ejection nozzle and the air suction member, and when the powder or granular material is charged into the measuring hopper, the end face of the discharge port is operated by the operation of the air supply means. A powdery or granular material measuring device, characterized in that a cylindrical air curtain is formed over the entire circumference of the gap between the end face of the charging port. 2. The air supply means generates an air supply source for sending out compressed air, a supply pipe connecting the air supply source and the air jet nozzle, and a negative pressure in the air suction member. An ejector, an intake pipe connecting the ejector and the air intake member, and a branch from the supply pipe, which is connected to the ejector, and forms a high-speed air flow in the ejector to generate a negative pressure. The powdery or granular material measuring device according to claim 1, further comprising a branch pipe. 3. The powder or granular material according to claim 1, wherein the air curtain is formed by the air supply means only when the powder or granular material is charged from the charging hopper into the weighing hopper. Weighing device.