JP3582672B2 - Powder supply device - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a powder supply device suitable for application to an airflow classification device that classifies raw materials to be classified supplied into a classification airflow according to particle size based on the Coanda effect, and particularly, powder is clogged or adhered. The present invention relates to a powder supply device capable of preventing the occurrence of a dust.
[0002]
[Prior art]
Conventionally, finely divided raw materials have been used in various industrial fields. For example, there is known an airflow classifier for classifying a powder obtained by pulverization into a predetermined particle size. This airflow classifier classifies the raw material to be classified supplied into the classification airflow according to the particle size based on the Coanda effect. The powder supply device that supplies powder as a raw material to the airflow classifier sends a fixed amount of powder by vibrating the powder by a combination of a table feeder and an electromagnetic feeder, and hoppers the sent fixed amount of powder. And discharged from the powder outlet of the hopper.
[0003]
The powder discharged from the hopper is supplied to an ejector casing, where the powder is primarily dispersed by pressure air sent into the ejector casing from an ejector nozzle, and then ejected into the airflow classification device by the pressure of the compressed air. Conventional hoppers are generally formed in a downwardly conical shape from a metal such as steel or stainless steel, and discharge the powder into an ejector casing by free fall.
[0004]
[Problems to be solved by the invention]
By the way, the performance of the airflow classifier depends on the dispersibility of the powder in the powder supply device. The powder delivered from the fixed-quantity feeder has poor fluidity due to the powder's adsorbability, fusion property, and charging property. In addition, the hopper has a downward conical cone shape, and discharges powder by free fall. Aggregate.
[0005]
As described above, the conventional powder supply apparatus may supply the powder having a pseudo-large particle size to the airflow classification device due to agglomeration, and the classification performance of the airflow classification device is reduced. there were. Further, in the conventional powder supply device, the powder adheres to the inner surface of the hopper and narrows the powder outlet, and in some cases, the amount of adhered powder becomes too large and the powder is not discharged from the powder outlet. There was something like that.
[0006]
Conventionally, as one method for solving such a problem, pressurized air was supplied into the hopper to peel off and remove the powder attached to the inner surface. The powder may further adhere to the inner surface of the hopper, contrary to the expected effect, due to moisture or moisture.
In addition, another method has been proposed in which a brush is moved up and down in the hopper at appropriate time intervals to peel off the powder adhering to the inner surface of the hopper and to push out the powder clogged in the powder outlet. In this method, the fibrous member constituting the brush falls off and enters the airflow classifier, or the cohesive and crushed powder peeled from the inner surface of the hopper by the brush enters the airflow classifier. As a result, there is a possibility that the performance of the airflow classification device is reduced and the quality of the classified product is reduced. Further, there is a possibility that a new problem may occur that the inner surface of the hopper is scratched by the brush and the powder easily adheres to the scratched portion.
[0007]
Therefore, an object of the present invention is to solve the above-mentioned problems, and it is possible to remove the powder having an excessively large particle size to prevent the performance of the powder processing apparatus from being reduced, and to prevent the powder from adhering to the inner surface of the hopper. And a powder supply device capable of preventing the powder outlet of the hopper from being clogged with powder.
[0008]
[Means for Solving the Problems]
The above object of the present invention is to provide a powder supply device which is arranged between an external powder sending means and a powder processing means and supplies the powder sent from the powder sending means to the powder processing means. In, a hopper means for collecting the powder delivered from the powder delivery means and discharging from the powder outlet, and the powder discharged from the powder outlet into the powder processing means by a pressurized gas Powder supply means for ejecting the powder, and a passing particle size restricting means for restricting a passing particle diameter of the powder is provided near a powder outlet of the hopper means. can do.
[0009]
The above object of the present invention can be achieved by a powder supply device, wherein the passing particle size limiting means is detachably attached.
The above object of the present invention can be achieved by a powder supply device, wherein a vibration means for vibrating the passing particle size limiting means is provided.
Further, the above object of the present invention is characterized in that the hopper means is configured to discharge the powder by free fall, and a contact surface of the hopper means with the powder is formed of a fluorine resin. This can be achieved by a powder supply device.
[0010]
[Action]
In the powder supply device of the present invention, when the powder delivered from the external powder delivery means passes through the comb-shaped passing particle size limiting means provided near the powder outlet of the hopper means, a predetermined The powder larger than the particle size is stopped by the comb teeth, and only the powder having a predetermined particle size or less is sent to the powder ejection means. Therefore, it is possible to prevent the powder from being clogged in the vicinity of the powder outlet, and since the powder supplied to the powder processing means does not contain excessive powder, the powder processing performance of the powder processing means is improved. .
[0011]
In addition, the powder having a large particle diameter accumulated on and between the comb teeth of the passing particle diameter limiting means and the fine particle components adhered and fused to the surface of the comb teeth are sucked from the upper side of the hopper or passed therethrough. The particle size limiting means can be removed and easily removed. In addition, by vibrating the passing particle size restricting means by the vibrating means, the aggregated particles are crushed, and the accumulation of powder on the comb teeth and between the comb teeth can be suppressed.
[0012]
Further, since the inner surface of the hopper means which is in contact with the powder when it falls freely is formed of a fluorine resin having a small coefficient of friction, the powder can be prevented from easily sliding down and adhering to the inner surface of the hopper.
[0013]
【Example】
Next, an embodiment of a powder supply apparatus according to the present invention will be described in detail with reference to FIGS. 1 is a cross-sectional view of a powder supply device and an airflow classifier according to the present invention, FIG. 2 is an enlarged view of the powder supply device, FIG. 3 is a cross-sectional view taken along line AA of FIG. 2, and FIG. FIG. 5 is a sectional view taken along line BB of FIG.
[0014]
As shown in FIG. 1, a powder supply device 1 according to the present invention can be applied to, for example, an airflow classifier 2. The powder supply device 1 includes a hopper 11 as hopper means, an ejector nozzle 12 as powder ejection means, and an ejector casing 13. The hopper 11 is supplied with the raw material powder dispersed by the table feeder 3 and the electromagnetic feeder 4 serving as powder sending means. The supplied powder is collected in the hopper 11 and discharged from the powder outlet 14. The discharged powder falls in the middle of the ejector casing 13. An ejector nozzle 12 is inserted on the inlet side of the ejector casing 13, and the powder supplied in the middle of the ejector casing 13 is supplied to the raw material supply nozzle 21 of the airflow classifier 2 by the pressure air sent from the ejector nozzle 12. Sent out.
[0015]
As shown in FIG. 2, the hopper 11 of the powder supply device 1 is provided with a grizzly bar 15 which is a comb-tooth-shaped particle diameter limiting means in the vicinity of the powder outlet 14, for example, at a position of about 60 mm to 70 mm. . The grizzly river 15 prevents powder having a predetermined particle size or more from clogging in the powder outlet 14 and the ejector casing 13, and also prevents excessive powder from being supplied to the airflow classifier 2 and lowering the classification performance. It is provided in order to perform. As shown in FIG. 3, a plurality of round bars 16 made of, for example, stainless steel are arranged in parallel in the grizz river 15, and are fixed to a support plate 17.
[0016]
The gap d between adjacent round bars 16 is smaller than the gap d0 of the narrowest portion 18 in the powder passage of the ejector casing 13. The grizz river 15 is attached by inserting the round bar 16 into a plurality of through holes 19 arranged horizontally on both side walls of the hopper 11. The gap between the through hole 19 and the round bar 16 is very small so that the powder does not leak. A vibration element 20 is attached to the grizz river 15 and is controlled by a controller 21.
[0017]
The hopper 11 is configured to drop the powder freely and supply the powder to the ejector casing 13. The inner surface of the hopper 11 is coated with a fluoro resin 62. The fluorine resin 62 is water-repellent, has a small friction coefficient, and has insulating properties. The fluororesin 62 can be applied to the inner surface of the hopper 11 by spraying or pouring, and then heat-sintered at 200 to 250 ° C. to form a film of 30 to 50 μm.
[0018]
The airflow classifier 2 shown in FIG. 1 classifies powder using the flight trajectory of particles based on the Coanda effect. A classifying chamber 24 is provided between the Coanda block 22 and the coarse powder side block 23. The above-described raw material supply nozzle 21 is provided on the side of the classification chamber 24. On the upper side of the classifying chamber 24, classifying airflow inlets 25 and 26 are provided.
[0019]
A first classification edge 27 and a second classification edge 28 are provided on the lower side of the classification chamber 24, and a fine powder discharge passage is formed by the Coanda block 22, the coarse powder side block 23, the first classification edge 27, and the second classification edge 28. 29, an intermediate powder discharge passage 30 and a coarse powder discharge passage 31 are formed. The tip of each of the classification edges 27 and 28 can be adjusted in position. The powder discharged from each of the discharge passages 29 to 31 is collected by an appropriate collecting means (not shown).
[0020]
Next, operations of the powder supply device 1 and the airflow classifier 2 will be described. As shown in FIG. 1, a fixed amount of powder is dispersed by the table feeder 3 and the electromagnetic feeder 4 and supplied to the hopper 11 of the powder supply device 1. In the hopper 11, the supplied powders are collected and fall freely, pass through the grizzly bar 15 to which vibration is applied by the vibration element 20, and are discharged from the powder outlet 14 to the middle of the ejector casing 13.
[0021]
When the powder falls freely in the hopper 11, a part of the powder falls while contacting the inner surface of the hopper 11. Since the inner surface of the hopper 11 is coated with the fluorine resin 62, it is possible to prevent the powder from easily sliding down and adhering or fusing to the inner surface.
Further, since vibration is applied to the grizz river 15, the powder accumulated on the round bar 16 and between the round bars 16 is decomposed by the vibration and falls through the space between the round bars 16. Can be prevented from being clogged with powder. Furthermore, even if the powder accumulates on the upper side of the grizzly river 15, the powder is not hardened so much because the powder is accumulated by free fall, and the powder is periodically sucked from the upper opening of the hopper 11 with a vacuum cleaner or the like. Further, even when the grizzly river 15 adheres or fuses to the grizzly river 15 itself, the powder can be easily removed by pulling out the round bar 16 of the grizzly river 15 from the through hole 19 of the hopper 11.
[0022]
The powder discharged from the powder outlet 14 to the ejector casing 13 after passing through the grizz River 15 is only the powder that has passed through the gap d between the round bars 16 of the grizz River 15 as shown in FIG. Since it is smaller than the gap d0 (FIG. 2) between the narrowest portions 18 of the ejector casing 13, it is possible to prevent the powder from clogging the narrowest portions 18. If the powder is clogged in the narrowest portion 18, the powder is hardened by the compressed air flowing from the ejector nozzle 12, and it takes considerable time to remove the powder. However, in the powder supply device 1 of the present invention, Since the powder is collected on the upper side of the detachable grizzly river 15, it is possible to easily clean the powder.
[0023]
The powder supplied to the ejector casing 13 is primarily dispersed by the compressed air sent from the ejector nozzle 12, and is ejected to the classification chamber 24 via the raw material nozzle 21 of the airflow classifier 2. The classification chamber 24 is supplied with a classification airflow from inlets 25 and 26. Then, the powder supplied to the classifying chamber 24 has a flight trajectory of the particles enlarged at the curved surface portion of the Coanda block 22, and the fine powder having a small inertia force flowing along the wall surface of the Coanda block 22 by each of the classification edges 27 and 28. Is classified into coarse powder having a large inertia flowing at a position farthest from the Coanda block 22 and intermediate powder having an inertia between the fine powder and the coarse powder. Then, the classified powder is collected by the collecting means via the fine powder discharge passage 29, the intermediate powder discharge passage 30, and the coarse powder discharge passage 31.
[0024]
The powder supplied from the raw material nozzle 21 into the classification chamber 24 is restricted to a predetermined particle size or less by the powder supply device 1 and is primarily dispersed in the ejector casing 13. And the quality of the classified product can be improved.
In the above-described embodiment, the through holes 19 are provided on both side walls of the hopper 11, and the round bar 16 of the grizzly bar 15 is inserted into the through hole 19 to attach the grizzly bar 15, as shown in FIG. The mounting block 51 is fixed to one side wall of the hopper 11, and a plurality of mounting holes 52 penetrating the mounting block 51 including the side wall of the hopper 11 are horizontally arranged. By inserting the round bar 54, the grizzly bar 53 can be removably attached. The grizzly bar 53 has a plurality of round bars 54 arranged horizontally like the above-described grizzly bar 15, and this is fixed to a support portion 55. Also in this case, as shown in FIG. 5, the gap d between the round bars 54 of the grizzly river 53 is set smaller than the gap d0 (FIG. 4) between the narrowest portions 18 of the ejector casing 13.
[0025]
In addition, there is a possibility that the powder raw material leaks out of the gap between the mounting hole 52 formed in the hopper wall surface 11a of the hopper 11 and the fitting portion of the grizzly river 53. However, in the present embodiment, as shown in an enlarged view in FIG. 6, for example, a configuration in which an O-ring (O-ring) 60 is mounted in the mounting hole 52 is employed, so that leakage of powder can be prevented. Can be. As for the mounting structure of the O-ring 60, as shown in the drawing, an annular concave portion for mounting the O-ring 60 is formed on the outer surface of the hopper of the mounting hole 52, and the O-ring 60 is mounted in this concave portion. The holding plate 65 is fixed by screwing or the like to hold the O-ring 60.
[0026]
In the case of a configuration in which the grizz River 53 vibrates appropriately by a vibrating element, the gap between the mounting hole 52 and the grizz River 53 is formed so as not to interfere with both portions, so that Unnecessary rubbing or breakage of the portion can be avoided, and leakage of the powder material from the mounting hole 52 due to vibration can be effectively prevented.
[0027]
In the configuration shown in FIG. 4 in which the tip end of the grizz river 53 does not pass through the hopper 11 and the vibration element is provided, it is desirable that the tip end does not contact the inner surface of the hopper. On the other hand, in the type (see FIG. 2) in which the tip portion of the grizzly river 53 fits the hopper 11, the structure on the tip portion side is of course provided with an O-ring as shown in FIG.
[0028]
Further, in the above embodiment, the inner surface of the hopper 11 is coated with the fluororesin 62. However, the fluororesin may be formed in a thin plate shape by a powder metallurgy method, and this may be adhered to the inner surface of the hopper 11. Further, the surfaces of the round bars 16 and 54 of the grizzly bars 15 and 53 may be coated with a fluorine resin, or the round bars 16 and 54 may be formed of a fluorine resin. This can prevent the powder from adhering to the round bars 16 and 54 and fusing.
[0029]
【The invention's effect】
In the powder supply apparatus of the present invention, a passing particle size restricting means is provided near the powder outlet of the hopper means, and a fluorinated resin is provided on the inner surface of the hopper means. Therefore, according to the present invention, it is possible to prevent the powder from being clogged in the powder passage between the powder processing means and the hopper means, and to reduce the powder discharged from the hopper means to a predetermined value. Since the particle size is limited to the particle size or less, the powder processing performance of the subsequent powder processing means is improved. In addition, since vibration is applied to the passing particle size restricting means by the vibrating element, it is possible to suppress the accumulation of powder on the passing particle size restricting means, and further to prevent the aggregation of the powder even if it accumulates. In addition, a part of the powder that falls freely in the hopper means comes into contact with the fluororesin on the inner surface of the hopper means and slides down, so that it is possible to prevent the powder from adhering or fusing to the inner surface of the hopper means.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a powder supply device and an airflow classification device according to the present invention.
FIG. 2 is an enlarged view of a powder supply device.
FIG. 3 is a sectional view taken along line AA of FIG. 2;
FIG. 4 is a cross-sectional view illustrating another embodiment of the grizzly river.
FIG. 5 is a sectional view taken along line BB of FIG. 4;
FIG. 6 is an enlarged view of a main part of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Powder supply apparatus 2 Air flow classifier 11 Hopper 12 Ejector nozzle 13 Ejector casing 14 Powder outlet 15, 53 Grizz river 16, 54 Round bar

Claims (4)

In a powder supply device arranged between an external powder sending means and a powder processing means, for supplying the powder sent from the powder sending means to the powder processing means,
A hopper means for collecting the powder sent from the powder sending means and discharging the powder from a powder outlet,
Powder ejection means for ejecting the powder discharged from the powder outlet into the powder processing means by a pressurized gas,
A powder supply device, wherein a passing particle size limiting means for limiting the passing particle size of the powder is provided near a powder outlet of the hopper means. 2. The powder supply device according to claim 1, wherein said passing particle size limiting means is detachably attached. The powder supply device according to claim 1, further comprising a vibration unit that vibrates the passage particle size restriction unit. The powder supply according to claim 1, wherein the hopper means is configured to discharge the powder by free fall, and a contact surface of the hopper means with the powder is formed of a fluoro resin. apparatus.

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