JP4564153B2 - Powder feeder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention uses a powder supply device, more specifically, a rotary table having a plurality of measuring chambers, and continuously and quantitatively supplies the powder in the powder storage tank to the pneumatic transport line. The present invention relates to a powder supply apparatus.
[0002]
[Prior art]
One typical example of a powder supply device that continuously and quantitatively supplies powder in a powder storage tank to a pneumatic transport line by a rotary table having a plurality of measuring chambers is provided in the pneumatic transport line. A powder storage tank in which an opening for opening is formed, and a plurality of measuring chambers are formed that are rotatably disposed in the powder storage tank and introduce powder into the circumferential direction of the outer periphery and discharge it to the discharge outlet. And a rotating table. When the rotary table is rotationally driven by the electric motor, each of the weighing chambers is formed before and after the introduction portion for introducing the powder, the discharge portion for discharging the powder to the discharge port, and the rotation direction of the discharge port. The chamber is moved through the front closure and the rear closure where the chamber is blocked.
[0003]
The powder introduced into the measurement chamber in the introduction part is measured by being regulated in the volume of the measurement chamber by closing the measurement chamber in the front closing part following the introduction part. When the metering chamber moves to the subsequent discharge section, the blockage of the metering chamber is released, and the powder is discharged to the pneumatic transport pipe through the discharge port. The discharged powder is sent to a predetermined place by the pressure air flowing through the air transportation pipeline.
[0004]
The empty measuring chamber in which the powder is discharged in the discharge portion is passed through the subsequent rear closing portion and closed. In this closed measurement chamber, the pressure air from the air transport line communicating with the discharge portion flows (hereinafter, the pressure air flowing into the measurement chamber is referred to as replacement air or replacement pressure air). There is). The measurement chamber that has passed through the rear blocking portion moves again to the introduction portion in the powder storage tank, and the powder in the powder storage tank is again introduced into the empty measurement chamber.
[0005]
Thus, the powder is continuously and quantitatively supplied to the pneumatic transport line by defining the volume of the measuring chamber of the rotary table, the number of rotations, and the like.
[0006]
In the powder supply apparatus configured as described above, the closed portion formed before and after the powder discharge port has an important role in addition to the purpose of closing the measuring chamber and measuring the powder. Yes. That is, the measurement chamber closed by the front blocking portion and the rear blocking portion prevents the pressure air flowing through the air transport pipe having the discharge port from flowing into the powder storage tank. If a large amount of compressed air in the pneumatic transportation line leaks into the powder storage tank, proper pneumatic transportation of the powder becomes impossible. Therefore, the gap between the measuring chamber, for example, the scraping plate and the bottom wall, which is in sliding contact with the opening of the measuring chamber, which is a means for closing the measuring chamber, is made as small as possible to avoid leakage of pressure air as much as possible. This is very important.
[0007]
[Problems to be solved by the invention]
However, the conventional powder supply apparatus having the configuration as described above has the following problems to be solved.
[0008]
In other words, even if the gap between the measuring chamber and the scraper plate, bottom wall, etc. that are in sliding contact with the measuring chamber is minimized, the replacement pressure air that has entered the measuring chamber from which the powder has been discharged is When moving from the closed part to the powder introduction part and releasing the blockage of the measuring chamber, the powder is discharged into the powder in the powder storage tank and blown up. In this way, the flow of pressurized air into the powder storage tank is not only from the gap between the weighing chamber and the ground plate, bottom wall, etc. that slides in contact with it, but also the rotating table rotates and the weighing chamber is discharged from the rear blocking part. It always occurs when moving to the body introduction and cannot be avoided. In addition, when the powder is transported to a distant location or at a high location, or when the mass of the powder increases, the pressure of the pressure air flowing through the transport pipe inevitably increases, and the air released into the powder storage tank The amount, and the blow-up will be bigger.
[0009]
And, the compressed air released into the powder storage tank passes through the powder and is released to the outside.
(1) Blow up the powder to generate dust,
(2) Air is mixed into the powder, the bulk density of the powder (the weight of the powder per unit volume) is reduced, the amount of powder introduced into the measuring chamber is reduced, and quantitative properties cannot be maintained. Problems occur.
[0010]
The present invention has been made in view of the above-mentioned facts, and the main technical problem thereof is to supply powder continuously and quantitatively to the air transport pipe using a rotary table having a plurality of measuring chambers. In the powder supply device, it is possible to prevent the pressure air in the powder transport line from flowing into the powder storage tank through the measurement chamber that is emptied by discharging the powder. Is to provide a device.
[0011]
[Means for Solving the Problems]
In the present invention, as a powder supply device that solves the above technical problem, a powder storage tank in which a discharge port that opens to an air transportation pipeline is formed, and an outer peripheral portion that is rotatably disposed in the powder storage tank A rotary table formed with a plurality of weighing chambers for introducing powder into the circumferential direction and discharging it to the discharge port, and closing the measurement chamber formed before and after the discharge port in the rotation direction of the rotary table. Powder that is formed by flowing the pressure air of the air transport pipe formed in the front opening part and the rear side closing part for closing the space between the powder storage tank and the discharge port and the opening of the discharge port The ejector is provided in a cylindrical ejector installation portion that constitutes a part of the air transport pipe formed in the opening portion of the discharge port of the powder storage tank, A nozzle that injects the compressed air at a high speed, and downstream of the nozzle Vignetting and a diffuser for expanding the flow channel gradually, the discharge port communicates between the nozzle and the diffuser, the metering chamber is located within the ejector installation portion of the cylindrical shape in the discharge port A powder supply device is provided.
[0012]
In the powder supply apparatus according to the present invention, an ejector having a suction action is provided at a portion of the discharge port from which the powder is discharged. Since the pressure at the discharge port is lowered by the suction action of the ejector, the pressure of the replacement air flowing into the emptied measuring chamber is reduced, and the pressure air is prevented from flowing into the powder storage tank. . Therefore, the conventional problems such as the generation of dust when powder is blown up, the bulk density of the powder becomes small, and the quantitative property of the powder cannot be maintained are solved.
[0014]
And the pressure air of the air transportation pipeline is lowered by reducing the pressure of the replacement air in the measuring chamber while lowering the static pressure at the portion ejected from the nozzle and sucking the discharged powder, and passing through the diffuser. The static pressure is increased again.
[0015]
In another embodiment, a discharge nozzle for injecting pressurized air toward the measurement chamber located at the discharge port is provided. Further, the discharge nozzle is supplied with the pressure air taken out from the air transport pipe that is branched upstream of the ejector.
[0016]
Then, the powder in the measurement chamber is easily and completely discharged by the jet pressure air of the discharge nozzle. Further, the pressure air in the air transport pipe is branched and allowed to flow to the discharge nozzle, so that the discharge nozzle can be installed without providing a separate pressure air circuit.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of a powder supply apparatus constructed according to the present invention will be described in more detail with reference to the accompanying drawings.
[0018]
Referring to FIGS. 1 and 2, the illustrated powder supply apparatus includes a powder storage tank 6 in which a discharge port 4 that opens to the air transport pipe 2 is formed, and a powder storage tank 6 that is freely rotatable. And a turntable 10 having a plurality of weighing chambers 8 having an upper opening 8a and a lower opening 8b for introducing and discharging powder in the circumferential direction of the outer peripheral portion. An ejector 12 having a suction action is provided in a portion of the air transport pipe 2 where the discharge port 4 is opened, by allowing pressurized air flowing through the air transport pipe 2 to pass therethrough.
[0019]
Each of the weighing chambers 8 is discharged to the introduction part to which the powder indicated by X is introduced and the discharge port 4 indicated to Y when the rotary table 10 is rotated in the direction indicated by the arrow R (FIG. 2). Moved through the discharge section. In the introduction part X and the discharge part Y, the upper opening 8a and the lower opening 8b are opened. Before and after the discharge part Y in the rotational direction R, a front side closed part indicated by reference numeral Z1 and a rear side closed part indicated by reference numeral Z2 are formed in which the upper opening 8a and the lower opening 8b of at least one weighing chamber 8 are closed. ing.
[0020]
The powder storage tank 6 includes a disk-shaped bottom wall 14 and a cylindrical peripheral wall 16 extending upward from the peripheral edge of the bottom wall 14. The part of the peripheral wall 16 includes a cylindrical et peptidase Kuta installing portion 18 extending in the vertical direction to constitute a part of the air transport pipe 2 is provided. Outlet 4 of the powder are opened to the error zero Kuta installing portion 18. The bottom wall 14 is mounted on a cylindrical support frame 20. A rotary shaft 22 extending in the vertical direction is rotatably supported by the support frame 20, and one end (upper end) thereof is positioned so as to penetrate the bottom wall 14 and protrude into the powder storage tank 6. . Between the rotary shaft 22 and the bottom wall 14, a bearing / seal means 24, which can be constituted by a well-known one, is interposed. The rotary table 10 is fixed to the upper end portion of the rotary shaft 24. The other end (lower end) of the rotating shaft 22 is connected to an electric motor 26 attached to the lower end of the support frame 20.
[0021]
The turntable 10 includes a disk-shaped main body 28 and a plurality of partition plates 30 erected radially at predetermined intervals in the circumferential direction on the outer periphery of the main body 28. The pair of adjacent partition plates 30 and 30 cooperate with the inner surface of the peripheral wall 16 of the powder storage tank 6 to define the measuring chamber 8 having the upper opening 8a and the lower opening 8b. A boss 32 fixed to the rotary shaft 22 is formed at the center of the main body portion 28. Also, four agitating blades 34 for agitating the powder in the powder storage tank 6 are fixed to the boss 32 at equal intervals in the circumferential direction.
[0022]
The upper opening 8a and the lower opening 8b of the measuring chamber 8 are slidably contacted with a scraping plate 36 provided on the inner surface of the peripheral wall 16, and the lower opening 8b is a bottom wall in the front blocking part Z1 and the rear blocking part Z2. 14 are in sliding contact with each other and are respectively closed. The slitting plate 36 is formed by cutting a plate member into an arc shape with a width that closes the measuring chamber 8 disposed in the circumferential direction.
[0023]
The ejector 12 includes a nozzle 38 having a gradually reduced flow path for injecting pressurized air at a high speed, and a diffuser 40 provided downstream thereof and having a gradually expanded flow path. Nozzle 38 is fixed by penetrating the lid 39 closing the upper end of the d peptidase Kuta installing portion 18, the diffuser 40 closes the lower end of the d peptidase Kuta installing portion 18 is fixed through the lid 41. The inlet side of the diffuser 40 between the nozzle 38 and the diffuser 40, a tapered portion 42 connecting the inner surface of d peptidase Kuta installing portion 18 is provided. The ejector 12 has a suction action in which the static pressure around the pressurized air ejected from the nozzle 38 at a high speed is lowered by the ejector effect. When the ejected air is passed through the diffuser 40, the ejector 12 The static pressure is increased again.
[0024]
The pneumatic transport line 2 is connected to, for example, a roots blower 46 as a pressure air source. The pressure air discharged from the Roots blower 46 first flows into the nozzle 38 side of the ejector 12, and the pressure air discharged from the nozzle 38 is discharged from the discharge port 4 of the powder storage tank 6 at the subsequent tapered portion 42 and powder. Together with the powder, and flows together with the powder to a powder supply destination (not shown).
[0025]
Another embodiment of the powder supply apparatus will be described with reference to FIG. The powder supplying device in form, the discharge nozzle 50 for injecting compressed air toward the metering chamber 8 located at the outlet 4 comprises in the picture peptidase Kuta installing portion 18. Since the discharge nozzle 50 injects pressurized air toward the measuring chamber 8, the discharge nozzle 50 may be much smaller in diameter than the nozzle 38 of the ejector 12 provided in the air transport pipe 2, and is a straight thin tube. Is formed by. The discharge nozzle 50 is supplied with pressurized air taken out by a pipe 52 that branches upstream from the installation portion of the ejector 12 in the air transport pipe 2. The conduit 52 is provided with an on-off valve 54 that can interrupt the flow of pressurized air as necessary. The powder in the measurement chamber 8 is completely discharged by blowing the pressure air from the discharge nozzle 50 to the measurement chamber 8 of the discharge port 4 if necessary.
[0026]
The operation of the powder supply apparatus as described above will be described with reference to FIGS.
[0027]
(1) Supply of powder to pneumatic transportation pipeline:
When the rotary table 10 is rotationally driven in the direction of arrow R by the electric motor 26, the powder stored in the powder storage tank 6 is placed in each of the weighing chambers 8 in the introduction portion X, mainly in the illustrated form. It is introduced from the opening 8a, moved along with the rotation of the turntable 10, and the amount is regulated and measured by the measuring chamber 8 in which the upper opening 8a and the lower opening 8b are closed in the subsequent front side closing portion Z1. . When the weighing chamber 8 moves to the discharge portion Y, the upper opening 8a and the lower opening 8b are unblocked, and the powder is discharged from the discharge port 4 into the ejector installation portion 18 provided with the ejector 12. The discharged powder is sucked by the action of the ejector 12, flows into the diffuser 40, and is sent to the powder supply destination (not shown) together with the pressure air. Low-pressure air that has been reduced in static pressure by the action of the ejector 12 flows into the measuring chamber 8 that has become empty as replacement air. The measuring chamber 8 containing the replacement air sequentially moves to the rear closed portion Z2.
The measuring chamber 8 that has passed through the rear blocking portion Z2 moves to the introduction portion X, and the powder is again introduced.
[0028]
(2) Preventing the release of substitution pressure air into the powder storage tank:
Since the low-pressure air, which has been reduced in static pressure by the suction action of the ejector 12 as described above, flows into the measurement chamber 8 where the powder has been discharged and emptied, the air therein is the pressure air in the air transport pipe 2. Since the pressure is much lower than that in the powder storage tank 6, the replacement air is not substantially discharged into the powder. Therefore, blowing up of the replacement air in the measuring chamber 8 into the powder as shown by the arrow H in FIG. 4 is prevented, and the generation of dust and the bulk density of the powder due to the mixing of air with the powder are reduced. Such problems are solved.
[0029]
(3) Discharge nozzle:
When the powder stored in the powder storage tank 6 is highly adherent, it may be difficult for the powder to spontaneously fall from the weighing chamber 8 by gravity at the discharge port 4. In this case, the open / close valve 54 of the pipe line 52 connected to the discharge nozzle 50 shown in FIG. 3 is opened, and the discharge nozzle 50 blows the pressure air to the measurement chamber 8 to completely discharge the powder from the measurement chamber 8. be able to.
[0030]
(4) Discharge nozzle:
The discharge nozzle 50 is easy to install because the compressed air is made to flow by branching the air transport pipe 2. Further, the amount of pressurized air flowing through the discharge nozzle 50 is much smaller than the amount of air flowing through the ejector 12, so that the suction action of the ejector 12 is not affected.
[0031]
As described above, the present invention has been described in detail based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications or corrections may be made within the scope of the present invention, for example, as described below. It is something that can be done.
[0032]
(1) Pressure air flow direction:
In the embodiment of the present invention, the direction of the flow of pressurized air in the air transport pipe 2 is made to flow from the upper side to the lower side (see FIG. 1) in the ejector installation portion 18 where the discharge port 4 opens. The installation form of the combination of the nozzle 38 and the diffuser 40 can be turned upside down so that the pressurized air flows upward from below.
[0033]
(2) Discharge nozzle:
In the embodiment of the present invention, the pressure air branched from the air transport pipe 2 is flowed to the discharge nozzle 50. However, if it is convenient to use an appropriate air pressure source, the pressure air source to the discharge nozzle 50 is You may make another.
[0034]
【The invention's effect】
According to the powder supply apparatus configured in accordance with the present invention, in the powder supply apparatus that supplies powder to the air transport pipe continuously and quantitatively using a rotary table having a plurality of measuring chambers. There is provided a powder supply apparatus capable of preventing the flow of pressurized air in the powder transport pipe into the powder storage tank through the measurement chamber which has been emptied by discharging the powder.
[Brief description of the drawings]
FIG. 1 is a side view showing an embodiment of a powder supply apparatus constructed according to the present invention.
FIG. 2 is a cross-sectional view taken in the direction of arrows AA in FIG.
FIG. 3 is an explanatory diagram of the action shown in the direction of arrow B in FIG. 2;
4 is a side view showing a form in which the powder supply apparatus shown in FIG. 1 is provided with a discharge nozzle. FIG.
[Explanation of symbols]
2: Pneumatic transport line 4: Discharge port 6: Powder storage tank 8: Measuring chamber 10: Rotary table 12: Ejector 38: Nozzle 40: Diffuser R: Rotating direction X: Introduction part Y: Discharge part Z1: Front side blocking part Z2 : Rear occlusion

Claims (3)

A powder storage tank having a discharge port opened to the air transport pipe, and a plurality of powder storage tanks rotatably disposed in the powder storage tank for introducing powder into the circumferential direction of the outer peripheral portion and discharging it to the discharge port A rotary table in which a single weighing chamber is formed, and a front blocking portion and a rear side that are formed before and after the discharge port in the rotation direction of the rotary table and close the measurement chamber and block between the powder storage tank and the discharge port A closing portion, and an ejector that is formed in a portion where the discharge port is opened and that sucks out the powder discharged by flowing the pressure air of the air transport pipe ,
The ejector is provided in a cylindrical ejector installation portion constituting a part of the air transport pipe formed in a portion where the discharge port of the powder storage tank is opened, and jets the pressurized air at a high speed. A nozzle and a diffuser provided downstream of the nozzle and gradually expanding the flow path, and the discharge port communicates between the nozzle and the diffuser;
The powder supply apparatus , wherein the weighing chamber is located in the cylindrical ejector installation portion at the discharge port . And a discharge nozzle for injecting pressurized air toward the measuring chamber located in the exhaust port, claim 1 Symbol placement of the powder feeder. The powder supply apparatus according to claim 2 , wherein the discharge nozzle is supplied with compressed air taken out from the upstream side of the ejector of the air transport pipe.

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