JPH08282855A - Powder supplying device - Google Patents

Abstract

PURPOSE: To precisely weigh a powder by providing a vibrating mechanism having a release hole having a hole diameter of a size such that the powder is passed, and the powder causes a bridge phenomenon at resting, which vibrates the powder in a discharge port and breaks time bridge phenomenon to discharge to powder. CONSTITUTION: A powder discharge port 7 is mounted on a powder storing part bottom part 3, and a conical substance 4 is arranged in a powder storing part 1. The powder storing part 1 has an upper opened cylindrical body part 1a, a lower throttled cone part 1b, and the powder discharge port 7 on the powder storing part bottom part 3. A vibrator 10 is mounted on the discharge port of the lower cone part 1b to control the discharge in the powder storing part 1. When the powder near the powder discharge port is thus vibrated to break a bridge phenomenon, fluidization is easy to cause, the powder is controlled to regulate the discharge quantity of the powder, and an uniform discharge can be performed. This device also has a mechanism for keeping the effective powder height of the powder storing part 1 and a device for measuring the discharged powder quantity, and the measuring device is interlocked with the vibrating device to take out the powder, and a high weighing precision can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder supply device for accurately measuring desired amounts of various powders and a powder supply device equipped with a powder measuring device.

[0002]

2. Description of the Related Art Heretofore, there have been known some methods for measuring powder by combining a powder supply device and an electronic balance. Types of powder supply device include screw type, table type, gutter-shaped electromagnetic feeder type and the like.

[0003]

A screw type powder feeding device is a device for rotating a screw to discharge a predetermined amount. When determining the discharge amount, the physical properties of the powder are determined. At the same time, it is necessary to design the screw diameter, rotation speed, pitch, etc. each time. This work requires a lot of experience and experimentation with real powders,
It's very difficult. The amount of discharge can be changed by changing the rotation speed, but the variable range of rotation speed is limited, and there is the trouble of redesigning the screw and replacing it with a new screw.

To further improve the weighing accuracy, when the set value is close to the upper limit, the screw rotation speed is decreased to discharge a small amount, but the powder falls after the stop, and it is difficult to improve the accuracy. It has the drawback of being difficult to control.
Further, depending on the physical properties of the powder, there is a defect that the powder becomes a gel and is fixed by the rotation of the screw, or becomes a nodule, which causes troubles. When switching to another powder, it is necessary to clean the inside, it is difficult to completely remove the powder used before, and there is a drawback that it takes more time.

The table type powder supplying device is a device for adjusting the discharge amount by changing the number of rotations of the table and the height of the weir on the table, and discharging the determined amount. In that case, it is necessary to design the diameter, rotation speed, and weir height of the table according to the physical properties of the powder. This work is very difficult as it requires a lot of experience and experiments using actual powders. It is possible to change the discharge amount by changing the rotation speed and the weir height, but there is a drawback that the variable range of the rotation speed is limited and it is very difficult to find the condition.

In order to further improve the weighing accuracy, the table rotation speed is lowered or the weir height is lowered near the upper limit of the set weighing value. It has the drawback of being difficult to raise and difficult to control. Further, when switching to another powder, it is necessary to clean the inside, it is difficult to completely remove the powder used before, and there is a drawback that it takes more time.

The gutter-shaped electromagnetic feeder type powder supply device is a device for vibrating a gutter-shaped elongated passage to discharge a predetermined amount. When determining the discharge amount, the physical properties of the powder are changed. In addition, it is necessary to design the frequency, the width of the gutter, and the length of the gutter each time. This work is very difficult as it requires a lot of experience and experimentation with the powder used.

In order to change the discharge amount, the frequency, the width of the gutter and the length of the gutter are changed, but there is a drawback that the variable range is limited and it is very difficult to find the condition. In addition, depending on the physical properties of the powder, the gutter may be used with its tip tilted downward, but in this case, the powder falls after the vibration is stopped, and it is difficult to improve accuracy and control is difficult. There is. Further, generally, the conventional powder feeder has a common serious drawback that it is difficult to feed the powder that causes the bridge phenomenon, particularly quantitatively and / or at a constant speed.

The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art. That is, according to the present invention, when determining the discharge amount, the discharge amount condition can be easily set without the need to redesign or remanufacture the device, and the powder can be supplied without a time lag with respect to the operation and stop of the device. Alternatively, the supply of the powder is stopped, and a device for automatically measuring the discharge amount of the powder in a short time with high accuracy is provided.

Further, the above-mentioned powder supplying apparatus is mainly of the type that discharges the powder mainly in the horizontal direction, and provides a device whose mechanism is basically different from that of the conventional powder supplying apparatus. Further, the present invention provides a device that has a simple internal structure, is easy to clean, and can easily change the powder type, as compared with the conventional device. Further, an object of the present invention is to provide a powder supply device which is particularly suitable for smoothly and quantitatively and / or at a constant speed to supply a powder which causes a bridge phenomenon.

[0011]

According to the present invention, in a powder supply device having a powder discharge port at the bottom of a powder storage unit, the discharge port is constituted by a single or plural open holes. Has a pore size that is large enough to allow the powder to pass through and causes the powder to bridge when stationary.
Further, a vibration mechanism for discharging powder by vibrating the powder in the vicinity of the discharge port to break the bridge phenomenon is provided, and the effective powder height of the powder storage unit is adjusted to a desired height if necessary. A device for measuring the amount of powder being discharged, if necessary, is provided, and the vibration mechanism of the measuring device and the powder supply device are interlocked to quantitatively obtain the desired amount of powder. And / or a powder supply device characterized by taking out at a constant speed.

In the apparatus of the present invention, the powder discharge port is composed of a single or a plurality of open holes, and the open holes are sufficient to allow the powder to pass through, and the powder causes a bridge phenomenon when stationary. A caliber with a size in the range of waking is used. The single or plural open holes can be selected in consideration of powder properties, physical properties, discharge amount, and the like. Depending on the particle size of the powder and the degree of bridging,
It is preferable to select a pore size in the range of several microns to several tens of millimeters. As the powder discharge port, a single or plural capillaries, a mesh plate, a mesh wire net, a porous sintered body, a fibrous net, or other fine perforation processing can be used.

In selecting one of these,
It is necessary to select an open hole diameter such as a capillary diameter or a wire mesh opening according to the powder to be supplied. As a selection criterion, a condition is applied in which the powder does not substantially pass due to a bridge phenomenon of the powder when stationary, and the powder passes without any trouble when vibration is applied. Considering handling and cost, it is desirable to use a thin mesh wire mesh. Regarding the thickness, for the above reason, as long as the shape is as thin as possible, and if the material is not deformed by the wear of the powder or the weight of the powder, metals, ceramics,
Any material such as plastic can be used.

Further, when a mesh wire net is used for the powder discharge port, it is preferable that the mesh wire mesh can be easily replaced so that it can be easily dealt with when changing the type of powder, when it is damaged, or when cleaning. Further, in order to improve the stable discharge amount of the powder, it is possible to select the one with the optimum opening.

As a vibrating mechanism for vibrating the powder in the vicinity of the powder discharge port of the powder storage unit to break the bridge phenomenon and discharge the powder, a mechanical vibrator is used as shown in FIG. Any of a method of applying vibration to the powder and a method of applying vibration to the powder while injecting air from a plurality of small diameter nozzles as shown in FIG. 5 can be adopted. As the type of the vibration mechanism, any method may be used as long as it uses electromagnetic vibration, ultrasonic vibration, high frequency vibration, a vibration motor, or the like, or a method of destroying the bridge phenomenon such as a method of blowing air as shown in FIG. Things may also be used.

The mechanism for keeping the effective powder height of the powder storage unit at a desired height is such that, during powder discharge, there is no fluctuation in the discharge amount regardless of fluctuations and changes due to the decrease of the upper surface of the powder, It is useful for ensuring stable reproducibility of continuous discharge. As a mechanism for keeping the effective powder height of the powder storage unit at a desired height, a method of keeping the powder upper surface constant with a level meter, or installing a cone-shaped object in the powder storage unit to control the powder pressure Any method of cutting can be adopted. As shown in FIG. 1, the bottom surface of the pyramidal shape can be easily spaced from the upper surface of the powder discharge port by a certain distance so that the discharge speed can be adjusted and stable continuity can be facilitated.

Further, when the powder is charged into the powder storage section when the powder storage section is empty, the bottom surface of the pyramid-shaped object is in contact with and closely adheres to the powder discharge port on the bottom surface of the powder storage section. Is convenient. The reason is that the vibration generated when charging the powder can prevent the powder from leaking from the powder discharge port. In the method of controlling the effective powder height with a level meter,
It is possible to separately install a powder feeder linked to the level meter, adjusting the discharge amount, and a device for preventing powder leakage from the powder discharge port. Therefore, as shown in FIG. 1, it is advantageous to install a cone-shaped object because it becomes a very simple mechanism.

In order to speed up the discharge and to improve the measurement accuracy, at the beginning of the discharge, the engine is operated at the maximum frequency or air amount, and when the value reaches 70 to 95% of the set measured value, the frequency or The amount of air can be reduced to enable fine metering and increase the metering accuracy. In this method, the powder does not drop after the vibration is stopped, and the discharge is reliably stopped, and the discharge amount of the powder can be measured automatically and accurately in a short time.

[0019]

The powder feeding and metering device of the present invention can discharge a bridge type one very easily. As shown in FIG. 1, if a powder discharge port is attached to the bottom of the powder storage unit and the powder in the vicinity of the powder discharge port is vibrated to break the bridge phenomenon, fluidization easily occurs. It is possible to realize uniform discharge by controlling the fluidity of powder and adjusting the discharge amount of powder and providing stable continuity. In addition, a mechanism for keeping the effective powder height of the powder storage unit at a desired height is provided, and a device for measuring the amount of powder being continuously discharged is provided. Accurate weighing accuracy can be obtained by quantitatively and / or constantly extracting a quantity of powder.

[0020]

EXAMPLE An example of the present invention will be described with reference to FIG.
As shown in FIG. 1, in this powder supply device, a powder discharge port 7 is attached to a powder storage part bottom portion 3, and a powdery material up-and-down mechanism 6 disposed inside the powder storage part 1 moves up and down. The pyramidal object 4 is arranged. The powder storage unit 1 has an upper barrel body 1a.
Is opened in a cylindrical shape, and the lower cone portion 1b is squeezed into a cone shape, and the powder discharge port 7 is attached to the powder storage bottom portion 3. The vibrator 10 is provided near the discharge port of the lower cone portion 1b.
Is attached to control the discharge of powder in the powder storage unit 1.

As the type of vibration mechanism, a method of using electromagnetic vibration, ultrasonic vibration, high frequency vibration, vibration motor, etc., or as shown in FIG.
Any method may be used as long as it is a method of destroying the bridge phenomenon, such as a method of blowing air through the air blowing port 15 through 6. In this example, electromagnetic vibration was used.

FIG. 2 is an explanatory diagram of the experimental result of measuring the integrated value of the discharge amount at a constant time when the pyramidal object 4 is attached. A 60-mesh wire mesh is attached to the powder discharge port 7, and the vertical lift of the cone-shaped object 4 is 5 m.
m. FIG. 3 is an explanatory diagram of an experimental result of measuring the integrated value of the discharge amount for each constant time when the pyramidal shape 4 is not attached. A mesh wire mesh of 60 mesh is attached to the powder discharge port 7. Comparing FIG. 2 and FIG. 3, the effect of attaching the cone-shaped object 4 is clearly recognized.

The cone-shaped object 4 has a lower cone portion 1b.
The inner wall surface and the outer peripheral portion of the conical bottom surface 5 can be set at arbitrary intervals, and the discharge speed can be easily adjusted. FIG. 4 is an explanatory diagram of an experimental result showing a discharging speed depending on a difference in lift of the cone-shaped object 4. A mesh wire mesh of 60 mesh is attached to the powder discharge port 7 to lift the cone-shaped object by 5 mm and 10 mm.
It is a measurement result as mm. According to this, it can be seen that the discharge speed can be easily changed depending on the height of the lift. In FIG. 4, a solid line indicates a lift of 5 mm, and a broken line indicates a lift of 10 mm.

The powder discharge port 7 attached to the powder storage bottom part 3 is a powder discharge port replacement mechanism 8 which can be easily removed.
It has. It has a structure that can be easily removed when it becomes clogged or damaged when used for a long time, when changing the product type, or when cleaning.

A measuring device is arranged below the powder storage unit 1. This weighing device measures the weight of the powder discharged from the powder storage unit 1. In this embodiment, the weighing device is an electronic balance 2 with a windshield. The actual weighing detection signal of the electronic balance 2 is input to the control device. The weighing method may be a weight loss method in which the main body of the powder supply device is mounted on the weighing machine, but it is not so preferable for the weighing machine when there is vibration or the like.

In order to measure the powder using this powder supply device, the upper lid 13 which is integral with the cone-shaped object 4 is attached to the powder storage unit 1. At this time, the bottom surface 5 of the pyramid-shaped object is at the lowest limit and is in close contact with the powder discharge port 7. Next, when the desorption powder container 9 is attached to the upper lid 13, the powder is supplied into the powder storage unit 1. Air is exhausted at the time of supply through the air exhaust port 12 attached to the upper lid 13. This air outlet 12
It is preferable to attach a paper filter of about a few microns and replace it from time to time.

The lift of the cone-shaped object 4 is set in advance so as to have a predetermined powder discharging speed, and then the controller 1
Set the weighing value with the weighing setter 1. At the same time when the weighing start button is pressed, the cone-shaped object 4 rises to a predetermined set lift, the vibrator 10 vibrates and passes through the gap between the cone portion 1b and the cone-shaped object bottom surface 5, and the powder discharge port 7 Discharge evenly. Receive this in a container and weigh it.

In order to improve the measuring accuracy, the vibration of the vibrator 10 is switched in two steps. 70% to 95 of the set weight
The maximum output is discharged up to about%, and then the frequency is reduced to 70% to 80% of the maximum frequency for operation.
Can calculate the difference between the detection signal of the actual weighing value and the signal of the preset weighing value, and control the vibrator 10 based on the calculated value to perform accurate weighing.

Table 1 shows that the mesh wire mesh is 60 mesh, the cone-shaped object lift is 5 mm, and the set measurement values are 5 g and 10 g.
Is the case. Regarding the frequency, up to 90% of the set measured value is discharged at the maximum frequency, and thereafter, the measurement results are shown when discharged at the frequency of 80% of the maximum frequency.

Since the present powder supply device can perform stable continuous discharge, it can be used alone as a powder supply device without being combined with the electronic balance 2. The application is applied to a wide range of fields such as pharmaceuticals, foods, general powder-related products, and fine measurement of analytical work.

[0031]

When the powder feeder according to the present invention is used, the structure is simple, the size is small, the powder type can be easily changed, and the cleaning is easy. In addition, since there are no moving parts, the powder properties are not impaired, there is no adhesion, agglomeration, or nodule, and stable continuous discharge is possible, so a powder supply device that can measure accurately and accurately in a short time is provided. To do.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an apparatus showing an overall configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an experimental result showing an integrated value of discharge amount at a constant time when a conical object is attached.

FIG. 3 is an explanatory diagram of an experimental result showing an integrated value of discharge amounts at constant time intervals when a conical object is not attached.

FIG. 4 is an explanatory diagram of an experimental result showing a discharge speed depending on a lift of a cone-shaped object.

FIG. 5 is an explanatory view of an apparatus for blowing air from a plurality of small-diameter nozzles in the vicinity of an outlet of a powder storage unit.

[Explanation of symbols]

 1 Powder Storage Section 1a Cylinder Body 1b Cone Section 2 Electronic Balance 3 Powder Storage Section Bottom 4 Cone Shaped Object 5 Cone Shaped Object Bottom 6 Cone Shaped Object Vertical Mechanism 7 Powder Discharge Port 8 Powder Discharge Port Replacement Mechanism 9 Desorption Powder container 10 Vibration device 11 Control device 12 Air exhaust port 13 Upper lid 14 Air pipe 15 Air blow port 16 Air blow pipe

[Table 1]

Claims (3)

[Claims] 1. A powder supply device having a powder discharge port at the bottom of a powder storage unit, wherein the discharge port is constituted by one or a plurality of open holes, and the open holes are sufficient to allow the powder to pass therethrough. And a vibration mechanism that has a hole diameter of a range in which the powder causes a bridge phenomenon when stationary, and further vibrates the powder near the discharge port to destroy the bridge phenomenon and discharge the powder. A powder supply device comprising. 2. The powder supply apparatus according to claim 1, further comprising a mechanism for keeping the effective powder height of the powder storage unit at a desired height. 3. A device for measuring the amount of powder being discharged is provided, and a desired amount of powder is quantitatively or at a constant speed by interlocking the vibration mechanism of the measuring device and the powder supply device. The powder supply device according to the first or second aspect, which is taken out.