JPS62176535A - Powder feeder - Google Patents

Abstract

PURPOSE:To extremely enhance the quantitative supply accuracy of a powder, by providing the jet orifice of dehumidified dry air to the lower part of the peripheral wall of a hopper and erecting a torsion bar on the upper surface of the cone provided to the bottom part of the hopper while providing a powder scraping blade to the bottom surface of the hopper. CONSTITUTION:For example, five torsion bars 10 having different lengths are erected on the upper surface of a cone 3 and not only a powder 1 is stirred but also the generation of a bridging phenomenon of the powder 1 caused by the stoppage of the gravitational flow of the powder 1 due to the accumulation pressure of the powder 1 is prevented by said torsion bars 10. Three spiral scraping blades 12 are provided to the bottom surface of the cone 3 at 120 deg.- positions in order to scraping out the powder 1 between the bottom surface of the cone 3 and the inner bottom surface of a hopper 3 from the center of the hopper 2 to the outer peripheral side. By scrapping out the powder 1, the rising in the temp. within the hopper 2 by the friction heat between the bottom surface of the cone 3 and the powder 1 stagnation on said bottom surface is prevented.

Description

[Detailed Description of the Invention] [Technical Field] This invention provides a method for supplying powder (including viscous material; the same applies hereinafter) to a powder processing device such as a crusher or a mixer, or discharging powder from a storage tank. This invention relates to a powder feeding machine used for

[Background technology]

Powder feeding machine (quantitative feeding device) widely used in general
Mechanically, ■Mechanically stirs and supplies powder;■
It is roughly divided into type 02, which blows compressed air to fluidize the powder and agitate and supply it.

In the case of powder supply by mechanical agitation (2), the gravity flow of the powder stops due to the powder's accumulation pressure, the temperature of the powder rises and softens as the temperature rises due to mechanical friction with the powder, and the powder absorbs moisture. There was a problem in that a crosslinking phenomenon occurred in the hopper due to such factors. Due to this crosslinking phenomenon, the supply of powder may be stopped, or the crosslinking may be temporarily broken and the powder may fall directly into the powder outlet of the hopper, resulting in oversupply. Further, there were also problems such as the powder being hardened by the heat of mechanical friction with the powder, and the hardened material being supplied, or overloading the feeder and causing it to stop.

■In the case of powder supply by air agitation, the particle size of the powder particles,
Segregation occurs in the powder tank due to differences in density, shape, etc.
Therefore, there is a problem in that the volume of the supplied powder varies.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a powder feeder with extremely high precision in quantitatively feeding powder.

[Disclosure of the invention]

In order to achieve the above object, the present invention includes a cylindrical hopper, a rotatable cone is concentrically provided at the bottom of the hopper, and powder is provided near the outer periphery of the bottom of the cone in the hopper. In the powder feeder, a metering feeder is connected to the outside of the hopper, and an injection port for injecting dehumidified and dried air is provided at the lower part of the peripheral wall of the hopper. The cone has a torsion bar erected on its upper surface, and a scraping blade for scraping the powder between the cone and the hopper toward the outer periphery on the bottom, The gist of the powder feeder is that a chopper for stirring the powder is provided at a small distance from the inner wall surface of the hopper.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a powder feeder according to the present invention. As shown in the figure, this powder feeder includes a cylindrical hopper 2 that stores powder 1, a cone 3 installed at the bottom of this hopper 2, and a quantitative feeder that transfers the powder 1 to the outside. 4. The cone 3 is provided concentrically with the hopper 2. An inlet 5 into which the powder 1 sent from the previous process is poured is provided at the center of the upper surface of the hopper 2, and a vent 6 equipped with a mesoche-like filter is provided at the side of the upper surface. ing. The powder 1 poured into the hopper 2 is agitated by the cone 3 rotated by a drive device 7 provided outside the hopper 2. This drive device 7 includes an electric motor M and a reducer 8 that reduces the rotation of the electric motor M. The output from the reducer 8 is transmitted through a rotating shaft 9, and the output from the reducer 8 is transmitted at a rotation speed of, for example, 3 rpm. Cone 3 is rotating. As shown in FIGS. 2 and 3, on the upper surface of this cone 3, torsion bars 10 and 10 having different lengths are provided.
There are five ... standing there. This torsion bar 10・
The powder 1 is agitated by the . In addition, torsion bar 10...
The lower end of has a spring structure with elasticity,
The cone 3 is prevented from being overloaded by contact with the powder 1. There is a hopper 2 on the outer periphery of the bottom of the cone 3.
A chopper 1) that stirs the powder 1 stored at the bottom of the
... are provided in three locations at the 120@ position. The chopper 1)... shown in Figure 1 is enlarged and shown in Figure 4. The smaller the distance between the outer end of the chopper 1) and the inner wall surface of the hopper 2, the better, and is preferably adjusted to, for example, 5 to 251-. In addition, as shown in Fig. 4, the distance between the chopper 1) and the lower surface of the hopper 2 and the angle θ of the angle θ are 3 to 5.
It is preferable that the f is adjusted to 1.5 to 15'' to scrape off the powder 1 adhering to the inner wall surface of the hopper 2. By this, the powder 1 adhering to the inner wall surface of the hopper 2 is scraped off. Prevents the growth of adhesion layers and therefore reduces the
This prevents the occurrence of crosslinking phenomenon. Further, in order to scrape out the powder l between the bottom surface of the cone 3 and the internal bottom surface of the hopper 2 from the center of the hopper 2 to the outer circumferential side, three spiral-shaped scraping blades 12 are provided at positions 1200 on the bottom surface of the cone 3. It is set in. By scraping out the powder 1, the temperature inside the hopper 2 is prevented from rising due to friction between the bottom surface of the cone 3 and the powder 1 staying on the bottom surface. Since it is possible to prevent the powder 1 from being hardened by frictional heat, there is no possibility that the cone 3 and the hopper 2 will bite into the hardened material.

This prevents overloading the drive device 7. When the powder 1 contains a low softening point resin, as described above, its temperature is prevented from rising, and therefore the occurrence of crosslinking due to softening of the powder 1 is also prevented. In the lower part of the wall surface of the hopper 2, eight injection ports 13 are provided through which dehumidified and dried air is injected. This dehumidified dry air is supplied to electric motor M2
For example, 3 to 7 by the near compressor 14 having
It is brought to a pressure of kg/cnl and sent to an air dryer 15, and then branched off at a header 16 and sent to each injection port 13... This dehumidified dry air is adjusted to a temperature of, for example, 15±5° C., and is sequentially injected from each injection port 13 for 0.1 seconds at intervals of, for example, 1 second. Due to this,
The stacking pressure of the powder 1 in the hopper 2 can be relaxed, and variations in the volume of the powder 1 can be reduced. Moreover, the relative humidity and absolute humidity inside the hopper 2 can be lowered and stabilized regardless of the outside air humidity. Therefore, the occurrence of crosslinking due to moisture absorption of the powder l is prevented. The powder 1 in the hopper 2 is guided to the discharge port 17 provided on the bottom surface of the hopper 3 near the bottom outer periphery of the cone 3 and discharged from the hopper 2 while being stirred as described above. This discharged powder 1 is quantitatively transferred to the next process by a screw-type quantitative feeder 4. Since the powder 1 stirred in the hopper 2 of the powder feeder does not produce any hardened or softened material, the quantitative feeder 4 may be stopped due to overload, or the quantitative feeder 4 may be stopped due to overload.
This prevents the powder supply port 18 from becoming clogged. Since the bulk specific gravity of the powder 1 becomes constant, more accurate quantitative supply becomes possible.

Using the powder feeder configured as described above, powder was fed under the following conditions, and the measurement results are shown in Table 1.

The dehumidified dry air injected from the injection port was supplied with powder under the same conditions as in the above example using another powder supply machine as a comparative example. The measurement results are also shown in Table 1. The powder feeder used as a comparative example was not provided with an injection port for ejecting dehumidified dry air. Further, the cone is provided with only one torsion bar and one scraper blade, and the distance from the inner wall of the hopper is wide, but choppers are also provided at three locations. Others were the same as in the example.

Judging from the "temperature of the powder in the hopper" shown in Table 1, it can be seen that there is an effect of suppressing the temperature rise of the powder. It was also found that it has the effect of lowering humidity, judging from the "relative humidity inside the hopper" and the "absolute humidity inside the hopper." It was also found from the "bulk specific gravity of the powder" that the deposition pressure was relaxed and the bulk specific gravity became more constant.

In the powder feeder according to the present invention, a rotary stirrer, a vibration stirrer, or a shaking stirrer may be installed in the hopper, and an electromagnetic pie break may be attached to the outer wall of the hopper. The crosslinking phenomenon caused by the powder in the hopper can be more reliably prevented.

In addition, although the injection ports were provided at eight locations in the embodiment, the number is not limited. However, the number is 6
-10 is desirable.

〔Effect of the invention〕

As described above, the powder feeding machine according to the present invention includes a cylindrical hopper, and a rotatable cone is concentrically provided at the bottom of the hopper, and the bottom of the cone in the hopper In a powder feeder in which a powder discharge port is provided near the outer periphery and a quantitative feeder is connected to the outside of this discharge port, dehumidified and dried air is injected into the lower part of the peripheral wall of the hopper. The cone has a torsion bar erected on its upper surface, and scraping blades are provided on its bottom surface for scraping the powder between the cone and the hopper toward the outer periphery. Since the chopper for stirring the powder is provided at a small distance from the inner wall surface of the hopper, it has the effect of greatly increasing the accuracy of quantitative supply of the powder.

[Brief explanation of drawings]

FIG. 1 is a sectional view illustrating a powder feeder according to the present invention, FIG. 2 is a sectional view of the powder feeder seen from above, and FIG.
The figure is a partially cutaway sectional view of the hopper and cone that constitute the powder feeder, and FIG. 4 is an enlarged view of section A in FIG. 1. 1...Powder 2...Hopper 3...Cone 4.
・Quantitative feeder -O...Torsion bar 1)・
... Chopper 12 ... Scraping blade 13 ... Injection port 17 ... Discharge port agent Patent attorney Takehiko Matsumoto Figure 1 Figure 3

Claims (6)

[Claims] (1) A cylindrical hopper is provided, and a rotatable cone is provided concentrically at the bottom of the hopper, and a powder discharge port is provided near the outer periphery of the bottom of the cone in the hopper. In a powder feeder in which a quantitative feeder is connected to the outside of this discharge port, an injection port for injecting dehumidified and dried air is provided at the lower part of the peripheral wall of the hopper, and the cone is A torsion bar is installed on the top surface, scraper blades are provided on the bottom surface to scrape the powder between this and the hopper toward the outer periphery, and a chopper for stirring the powder is installed on the outer periphery of the bottom inside the hopper. A powder feeder characterized by being installed at a small distance from a wall surface. (2) The powder feeder according to claim 1, which is provided with 6 to 10 injection ports. (3) The powder feeder according to claim 1 or 2, wherein three scraper blades are installed. (4) The chopper is 5 to 15 degrees to the rotation direction of the cone.
A powder feeder according to any one of claims 1 to 3, which is attached at an acute angle. (5) The distance between the chopper and the inner peripheral surface of the hopper is 5 to 25 mm.
A powder feeder according to any one of claims 1 to 4. (6) The powder feeder according to any one of claims 1 to 5, wherein the quantitative feeder is of a screw type.