JP3391490B2 - Powder transfer device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder conveying apparatus for separating powder from a wall surface of a conveying path and conveying it by utilizing mechanical vibration of a piezoelectric element or the like or positive and negative ions charged in the powder.

[0002]

2. Description of the Related Art Conventionally, as a device for conveying powder by mechanical vibration due to an electro-mechanical conversion element such as a piezoelectric element, a vibrating means using a motor or the like such as a vibrating feeder or a vibrating conveyor has a low frequency of about several tens Hz. Vertical vibration of frequency 20 to horizontal gutter
A technique is known in which the powder is slanted at 30 ° and the powder on the gutter is continuously bounced and conveyed. This is an excellent transportation method for short distances because the amount of transportation can be easily adjusted electrically and the required energy is relatively small.

Further, there is known a technique in which a corona discharge is carried out in the air from a discharge electrode to which a high DC voltage is applied, and the generated ions are attached to dust particles to be attracted to a dust collecting electrode like an electrostatic precipitator. ing.

[0004]

However, since the vibration frequency is low in the above-mentioned vibration feeder and vibration conveyor, the powder that is adsorbed on the wall surface of the conveying path among the conveyed powders has a displacement speed of vibration. However, if another powder having a different particle size or type remains to be conveyed by the same vibrating feeder or vibrating conveyor, the cleaning must be carried out every time.

The present invention focuses on the solution of such a problem, and an object thereof is to provide a powder carrier in which the powder does not adhere and remain on the inner wall surface of the carrier path.

[0006]

[0007]

[0008]

As a first means for solving the above problems, the present invention is designed so that vibration from a vibrator is transmitted to the outer surface of the wall surface of a powder conveying path for conveying powder in a predetermined direction. Connect the vibrator to the vibrator, connect the drive electric circuit that applies high frequency voltage to the vibrator, and sandwich the insulating layer on the wall surface.
Two types of surface electrodes, which have different polarities, are alternately striped and independent
And by arranging and connecting a voltage source an electric circuit for applying a voltage whose polarity changes at a predetermined time interval to the plane electrode, the composite vibration on the wall of the conveying path based on the vibration of the vibrator by the application of the high frequency voltage In addition to causing high-frequency vibration in which the nodes move irregularly, positive and negative ions generated along the wall surface of the transport path by the discharge current flowing in the surface electrode are charged to the powder in the transport path or attached to the wall surface. , Coulomb force generated due to the difference in polarity of the surface electrode electrostatically weakens the adsorption action of the powder.
While applying the
Then, the powder conveying device is configured to separate and convey the powder by the interaction of the vibration force and the Coulomb force .
Of .

[0009] Also, the as second means, the transducer of the plate-like piezoelectric element having a plurality of surface electrodes sandwiching the powder conveyance path insulating layer on the wall surface the inner surface of which conveys the powder in a predetermined direction to solve the above problems , And the oscillator and the surface electrode have different time phases.
Comprising a high frequency voltage to connect the electrical drive circuit for applying a high frequency of a plurality of positions by the vibrator by applying a high-frequency voltage
It occurred flexural vibration with shifted phase as the mobile wave, and alternately generates positive and negative ions in the vicinity of the wall surface by a surface electrode, the surface conductivity
The adsorption action of the powder by the poles is weakened electrostatically by the Coulomb force.
While moving, apply the vibration force of the moving wave by the oscillator
The powder adhering to the powder conveying path can be configured of a powder conveying apparatus comprising as conveyed is detached from the wall by the interaction of high frequency vibration force and the Coulomb force in the.

[0010]

[0011]

In the case of one surface electrode and a counter electrode placed in the vicinity thereof, or a plurality of surface electrodes insulated from each other, high DC voltages having different polarities are applied between the counter electrodes or between the multiple electrodes. Positive or negative ions are generated in the vicinity of each electrode, and the powder is separated from the wall surface by the same action as above. The voltage applied from the voltage source power supply circuit is optimally a value at which a dark current that does not result in electrical breakdown of air flows.

[0013]

According to the first solution, a high frequency voltage is applied from a drive electric circuit to a plurality of vibrators attached to the wall of the powder conveying path, and a plurality of electrodes provided on the wall are supplied from a voltage source electric circuit. Apply high DC voltage. Powder such two actions due to the addition of the by Ri functions to each of the applied voltage to interact with complex, adhering to the wall surface overlapping mechanical vibration force and electric Coulomb force To leave.

In the second solving means, when a high frequency voltage is applied from the drive electric circuit to the flat plate-shaped vibrator having the surface electrode attached to the wall surface of the powder conveying path, the vibrator causes lateral vibration on the wall surface. At the same time, since a high voltage is applied to the surface electrode of the vibrator, the powder attached to the wall surface is positively or negatively charged. Therefore, as in the case of the first solution, the mechanical vibration force and the electric Coulomb force are overlapped to separate the powder adhering to the wall surface.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the powder carrying device of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a vertical cross-sectional view of the powder carrying device according to the first embodiment. Reference numeral 1 denotes an inverted quadrangular hopper that is placed in the middle of the conveying path for powder transportation.
The ends of the two vibration expanding horns 4a and 4b are attached to the outer surface of the wall 2 of the above, and the two vibrators 5a and 5b including the electrostrictive bodies 3a and 3b, which are vibration sources, are connected to the respective expanding horns. . Each of the expansion horns 4a and 4b is attached at a position deviated from the node of the standing wave generated in the wall surface. The electrostrictive bodies 3a and 3b are connected to a drive electric circuit 6 that generates high-frequency voltages having temporal phases or frequencies different from each other. A powder supply nozzle 10 is arranged above the hopper 1.

In the powder conveying apparatus of this embodiment having the above-mentioned structure, when a high frequency voltage is applied from the drive electric circuit 6 to the electrostrictive bodies 3a and 3b of the vibrators 5a and 5b, the electrostrictive bodies 3a and 3b are moved. Each of the vibrators 5a, 5 due to the electrostrictive action
In b, vibration with a minute amplitude is generated in response to the high frequency voltage.
The amplitude of the vibration is magnified by the magnifying horns 4a and 4b, and the vibration of large amplitude is transmitted to the wall 2 of the hopper 1. At this time, since the vibrations of the vibrators 5a and 5b have different phases or frequencies from each other, two types of transverse wave vibrations having different phases or frequencies are also generated on the surface of the wall 2 which receives the vibration energy.

Then, the two kinds of transverse wave vibrations are combined, and the nodes of the combined vibration become moving waves which move irregularly. The oscillating force of the moving wave having a large displacement at a high speed overcomes the adsorption force of the powder adhering to the surface of the wall 2 and causes the powder to fly into the air. That is, the powder is separated from the conveying wall surface. Therefore, the powder falls to the outlet of the hopper 1 by gravity and is conveyed.

According to the powder conveying apparatus of the embodiment as described above, the adsorbed powder is bounced off by the high frequency vibration generated on the wall of the conveying path, and the high frequency vibration becomes a moving wave, and a standing wave is generated on the wall surface. Since no knots are generated, the powder does not agglomerate at the knots of the standing wave, and the wall surface can be kept clean.

FIG. 2 is a vertical cross-sectional view of the powder carrying device of the second embodiment, in which the same members as those in the first embodiment are designated by the same reference numerals. In this embodiment, two types of surface electrodes 8a and 8b, which are arranged in stripes with an insulating layer 7 sandwiched therebetween, and which have different polarities, are provided alternately and independently on the inner surface of the wall 2 of the hopper 1. A voltage source electric circuit 9 for generating a DC high voltage that changes between positive and negative at a time interval is connected to the surface electrodes 8a and 8b.

In the powder conveying apparatus of this embodiment having the above-mentioned structure, when a DC high voltage having a lower value than that at which dielectric breakdown of air is caused by the voltage source electric circuit 9 is applied to the surface electrodes 8a and 8b, the air is mediated by the air. And a weak discharge current is applied to the surface electrode 8
Flowing between a and 8b, positive and negative ions are generated in the periphery.
Of these ions, the ions having polarities different from those of the surface electrodes 8a and 8b are attracted to the surface electrodes 8a and 8b and most of them disappear. Then, each of the remaining ions adheres to the powder and is charged, and is adsorbed on the surfaces of the surface electrodes 8a and 8b.

On the other hand, the ions having the same polarity as the surface electrodes 8a and 8b are attached to the powder and charged, and are repelled by the Coulomb force together with the powder to move away from the surface electrodes 8a and 8b and to the wall 2 of the hopper 1.
To leave the plane. After that, when a certain period of time has passed and the polarities of the DC high voltage applied to the surface electrodes 8a and 8b are exchanged, the powder charged to the surface electrodes 8a and 8b and charged to the opposite polarity is changed to the surface electrodes 8a. , 8b and the same polarity, they separate from the wall 2 by Coulomb force. After that, a weak discharge is started in the same way as before the polarity was changed, and positive and negative ions are generated in the periphery. By repeating such an operation, the powder separates from the wall 2 and falls to the outlet of the hopper 1 by gravity and is conveyed.

As described above, in the second embodiment, since the high voltage with which the polarity is periodically changed is applied to the wall of the conveying path, the powder is charged and the powder adsorbed by the Coulomb force is adsorbed. You can bounce off and keep the walls clean.

FIG. 3 is a vertical cross-sectional view of the powder conveying device of the third embodiment, in which the same members as those in the first embodiment are designated by the same reference numerals. Reference numeral 1 is an inverted quadrangular hopper that is placed in the middle of the conveying path for powder transportation. An end of a vibration magnifying horn 4 is attached to the outer surface of the wall 2 of the hopper 1, and a vibrator 5 composed of an electrostrictive body 3 as a vibration source is connected to the magnifying horn. A drive electric circuit 6 that generates a high frequency voltage is connected to the electrostrictive body 3 of the vibrator 5.

On the other hand, on the inner surface of the wall 2 of the hopper 1, two types of surface electrodes 8a and 8b, which are arranged in stripes with the insulating layer 7 in between and which have different polarities, are provided alternately and independently. A voltage source electric circuit 9 for generating a DC high voltage that changes between positive and negative at a time interval is connected to the surface electrodes 8a and 8b.

In the powder conveying apparatus of this embodiment having the above-mentioned structure, when a high DC voltage is applied to the surface electrodes 8a, 8b from the voltage source electric circuit 9 as in the second embodiment, the surface electrodes 8a, 8b are formed. Positive and negative ions are generated in the periphery. And
The powder is charged with positive and negative ions, and adsorption and desorption by the Coulomb force are repeated on the electrode surface.

When a high frequency voltage is applied to the electrostrictive body 3 of the vibrator 5 from the drive electric circuit 6 in addition to the action of adsorbing and desorbing the powder by the surface electrodes 8a and 8b, vibration of large amplitude is generated in the hopper 1. It occurs on wall 2. Then, when the vibrating force of the vibrator 5 is further applied while the adsorption force of the powder adhered to the surface of the wall 2 is electrostatically weakened, the powder is blown off from the wall 2 and separated from the wall 2. Therefore, thereafter, the powder falls to the outlet of the hopper 1 by gravity and is conveyed.

In the third embodiment, since the high voltage is applied to the wall of the conveying path and the high frequency vibration is generated at the same time, the adsorbed powder is effectively released by the synergistic action of the vibration force and the Coulomb force. The wall surface can be kept clean.

Further, FIG. 4 shows a vertical cross-sectional view of the powder carrying device of the fourth embodiment. As in the first embodiment, reference numeral 1 denotes an inverted quadrangular hopper placed in the middle of the powder transporting path. On the inner surface of the wall 2 of the hopper 1, a plate-shaped piezoelectric vibrator 5d having a large number of rectangular surface electrodes 8c and 8d of 1/2 wavelength of a standing wave, and a large number of rectangular surface electrodes 8c 'and 8d. , The plate-shaped piezoelectric vibrators 5c each have 1/4 of the standing wave.
It is attached via the insulating layer 7 at a position separated by the wavelength. Then, the electrodes 8c, 8d, 8 of the vibrators 5c, 5d
The time phase is 90 ° between c'and 8d '.
A drive electric circuit 6 for generating different high frequency voltages is connected.

In the powder conveying apparatus of this embodiment having the above-mentioned structure, when a high frequency voltage is applied from the driving electric circuit 6 to the surface electrodes 8c, 8c ', 8d, 8d', the vibrator 5
A plurality of flexural vibrations out of phase occur in c and 5d. These bending vibrations are combined in the wall 2 and become a moving wave, which moves on the surface of the wall 2. At the same time, the surface electrodes 8c, 8c ',
Positive and negative ions are generated around 8d and 8d '.

Then, as in the second embodiment, the powder is charged with positive and negative ions, and adsorption and desorption by the Coulomb force are repeated on the electrode surface. At this time, the vibrating force of the vibrators 5c and 5d is further applied while the attraction force of the powder adhered to the surface is electrostatically weakened by the vibrators 5c and 5d, and the powder is blown off from the wall 2. The wall 2 is removed.
Therefore, thereafter, the powder falls to the outlet of the hopper 1 by gravity and is conveyed.

In the fourth embodiment, the plate-shaped electrostrictive body attached to the wall of the conveying path is used to simultaneously apply a high voltage and generate a high frequency vibration. Therefore, a synergistic effect of the vibration force and the Coulomb force is obtained. The adsorbed powder can be effectively released and the wall surface can be kept clean.

[0032]

As described in detail above , the first and second
According to the second aspect of the invention, the powder is bounced off by the combination of the high frequency vibration and the Coulomb force, or the powder is separated from the conveying surface, so that the wall surface can be always kept clean.
An advantage is obtained in that it is not necessary to perform cleaning to prevent foreign particles from being mixed.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a powder carrying device according to a first embodiment.

FIG. 2 is a vertical sectional view of a powder carrying device according to a second embodiment.

FIG. 3 is a vertical sectional view of a powder carrying device according to a third embodiment.

FIG. 4 is a vertical sectional view of a powder carrying device according to a fourth embodiment.

[Explanation of symbols]

1 hopper 2 walls 3, 3a, 3b Electrostrictive body 4, 4a, 4b Expansion horn 5, 5a, 5b, 5c, 5c ', 5d, 5d' transducers 6 drive electric circuit 7 Insulation layer 8a, 8b, 8c, 8c ', 8d, 8d' surface electrodes 9 Voltage source electric circuit 10 supply nozzles

Claims (2)

(57) [Claims] 1. A drive electric circuit for connecting a vibrator to an outer surface of a wall surface of a powder carrying path for carrying powder in a predetermined direction so that vibration from the vibrator is transmitted, and applying a high frequency voltage to the vibrator. And connect the electrodes to each other with an insulating layer sandwiched inside the wall surface.
Two types of surface electrodes having different characteristics are alternately arranged in a striped pattern, and a voltage source electric circuit for applying a voltage whose polarity changes at regular time intervals is connected to the surface electrodes to apply the high frequency voltage. Based on the vibration of the oscillator due to the vibration of the oscillator, high-frequency vibration in which the nodes of the synthetic vibration move irregularly on the wall surface of the transport path is generated, and the positive and negative ions generated along the wall surface of the transport path by the discharge current flowing in the surface electrode are generated. The powder adhering to the inside of the transfer path or the wall surface is charged, and the Coulomb force generated due to the difference in the polarity of the surface electrode electrostatically weakens the powder adsorption action.
Vibration is applied by the vibrator while
A powder conveying device configured to separate and convey powder by the interaction of force and Coulomb force . 2. A flat-plate piezoelectric vibrator having a large number of surface electrodes with an insulating layer sandwiched between inner surfaces of a wall surface of a powder transfer path for transferring powder in a predetermined direction, and the vibrator and the surface electrodes are temporally arranged.
A drive electric circuit that applies high-frequency voltage with different phases is connected,
A plurality of phase shift and the flexural vibration occurred as a moving wave,
Moreover, positive and negative ions are alternately generated near the wall surface by the surface electrode, and the adsorption action of the powder by the surface electrode is electrostatic by Coulomb force.
The vibrational force of the moving wave
A powder conveying device configured to separate and convey the powder that has been attached to the powder conveying path by the interaction of the high frequency vibration force and the Coulomb force.