JPH05293407A - Powder nozzle - Google Patents

Abstract

PURPOSE:To achieve the highly efficient dispersion of a powder difficult by a powder nozzle by providing a powder jet orifice injecting a powder along with an air stream, a revolving guide hole introducing a high speed air stream into a vortex chamber and an air jet orifice having a focus in front of the powder jet orifice. CONSTITUTION:A powder jet orifice A injecting a powder sucked under negative pressure by the ejector action of an air stream along with the air stream, the annular vortex chamber 24 formed at the position surrounding the powder jet orifice A and a plurality of the revolving guide ports 22 spirally extended to the vortex chamber 24 to introduce a high speed air stream into the vortex chamber 24 in order to form a high speed revolving stream in the vortex chamber 24 are provided. An annular air jet orifice B is opened to the vortex chamber 24 on the side facing to the powder jet orifice A so as to be turned toward the front part of the powder jet orifice A to inject a high speed tapered conical vortex stream having a focus in front of the powder jet orifice A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder nozzle which disperses powder sprayed from a powder spray port by a high-speed swirl flow formed in front of the powder spray port.

[0002]

2. Description of the Related Art In a laser light scattering type particle size distribution measuring apparatus, a powder nozzle is used to disperse powder, and the dispersed powder is irradiated with laser light. The structure is such that the particle size is measured from the scattering angle. The powder nozzle has a structure in which the powder sucked under a negative pressure by a high-speed air stream is sprayed from a spray port to disperse the powder.

[0003]

However, in the conventional powder nozzle, the powder sucked by the negative pressure by the ejector action of the airflow is dispersed by being jetted from the nozzle together with the high-speed airflow. Are not dispersed in particles of the original size of the powder, and some particles may remain as aggregates that are aggregated and integrated, and may not be sufficiently dispersed in the original particle size of the powder. This has been one of the causes for lowering the accuracy of particle size distribution measurement.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object thereof is to provide a powder nozzle which can surely disperse the powder into the original particle size.

[0005]

In order to achieve the above object, in a powder nozzle according to a first aspect, a powder injection port through which negative pressure sucked powder due to an ejector action of an air flow is injected together with the air flow. And an annular swirl chamber formed at a position where the powder injection port is engaged, and a plurality of swirls extending into the swirl chamber and introducing a high-speed air flow into the swirl chamber to generate a high-speed swirl flow in the swirl chamber. A guide hole and an annular shape that is opened toward the front of the powder injection port on the side of the swirl chamber facing the powder injection port and that forms a tapered conical high-speed vortex with a focus in front of the powder injection port. And a gas injection port of.

According to a second aspect of the present invention, in the powder nozzle according to the first aspect, a high speed vortex flow formed by injection from a gas injection port is formed in a cylindrical shape in which an outside air suction hole is formed in an outer portion at a front end portion of the nozzle. A diffusion cylinder for promoting the powder dispersion action is attached.

[0007]

The high-speed swirling flow rectified by the swirl chamber becomes a uniform high-speed swirl flow from the annular gas injection port and is ejected toward the front of the liquid injection port in a tapered conical shape. The powder that is sucked by the ejector action of the air flow in the nozzle and is primarily dispersed is contacted with the high-speed vortex formed outside the nozzle as soon as it is ejected from the powder ejection port, and is secondarily dispersed to It has the original size of the particles that make up the body.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. 1 and 2 show an embodiment of the present invention. FIG. 1 is a vertical sectional view of a powder nozzle which is an embodiment of the present invention, and FIG. 2 is a core of a powder nozzle. Perspective view, FIG.
FIG. 4 is a front view of a main part of the powder nozzle, and FIG. 4 is an enlarged cross-sectional view around the swirl chamber.

In these drawings, reference numeral 10 is a nozzle body, and a compressed gas inflow port 12 is formed at the rear end portion of the body 10, and the inflow port 12 is provided with an injection passage 14 (14a, 14b) through an orifice 13. 15 (15a, 15
It extends to b) and opens to the front. A powder supply port 16 is opened on the side surface of the passage 14a, and the powder in the hopper 17 is supplied to the powder supply port 16 by being vibrated, and by the negative pressure of the airflow jetted forward from the orifice 13. The powder supplied to the supply port 16 is sucked and dispersed. That is, the powder sucked under negative pressure from the supply port 16 is primarily dispersed in the passages 14 and 15 and is ejected from the front end opening of the passage 15 forming the powder ejection port A.
The compressed gas inflow port 12 passes through a passage 18 extending in parallel with the passages 14 and 15, a circular supply passage 19 and a swirl guide hole 22 formed around the passage 15, and the swirl chamber 24 surrounding the powder injection port A. Extends to.

The swirl chamber 24 and the gas injection port B are shown in FIG.
As shown in FIGS. 3 and 4, a concave portion 21 for forming a swirl chamber is formed on the front surface.
However, it is configured by assembling the injection plate cap 27 to the disk-shaped core 20 having the groove 23 for forming the swirl guide hole on the outer periphery, and the air entering the swirl chamber 24 from the swirl guide hole 22. A high-speed swirling flow is generated in the swirl chamber 24 by the flow. Further, the swirl chamber 24 is formed with an annular gas jet port B opening in front of the powder jet port A. The high-speed swirling flow in the swirl chamber 24 is rectified in the swirl chamber 24, and thereafter, It is jetted forward from the gas jet port B. Therefore, a tapered conical high-speed vortex is jetted and formed forward with the point F as the focal point. Then, as soon as the powder that has been primarily dispersed in the passages 14 and 15 is jetted from the powder jet port A together with the high-speed air stream, it comes into contact with the high-speed vortex jets that have been jetted from the gas jet port B and is secondarily dispersed. The particle size is

Reference numeral 26a is an O-ring interposed between the rear end of the core 20 and the nozzle body 10, reference numeral 26b is an O-ring interposed between the core 20 and the spray plate cap 27, and reference numeral 26c is a spray plate cap. Reference numeral 26d denotes an O ring interposed between the nozzle front end cover 11 and the nozzle front end cover 11, and reference numeral 26d denotes an O ring interposed between the nozzle front end cover 11 and the nozzle body 10.

A cylindrical diffusion tube 30 is screwed onto the front end of the nozzle body 10. Reference numeral 31 indicates a screwed portion.
A plurality of side surfaces of the diffusion cylinder 30 (in the embodiment, the circumferential direction is divided into four equal parts 4
Individual) air holes 32 are opened, and when the gas is formed by injection from the gas injection port B, outside air is taken in from the air holes 32 to promote the powder dispersion of the high-speed vortex inside the cylinder 30. It has a function.

The powder injection area C of this powder nozzle
In, the powder is dispersed to the original particle size of the powder particles. That is, in the conventional nozzle, the average particle size when boron nitride was used as the powder was 11.
In contrast to the average particle size of 3 μm in this example, the average particle size is 8.7 μm as shown in FIG. 6, which is considerably smaller than that of the conventional nozzle.

FIG. 7 shows a case where the powder nozzle of this embodiment is applied to a particle size distribution measuring device. In FIG. 7, reference numeral 40 denotes a light emitting portion, and the laser light emitted from the He—Ne laser 42 is collimated by the collimator lens 44 and emitted into particles dispersed by the powder nozzle into particles. When the powder particles are irradiated with the laser light, the light produces a scattering pattern in the shape of a circumferential circle that varies depending on the particle size. ,
Processing is performed by the high-speed data collection unit 50. It can be said that the measuring accuracy of the particle size distribution measuring device is high in this measuring device because the powder is highly dispersed by the powder nozzle.

[0015]

As is apparent from the above description, according to the powder nozzle of the present invention, the high-speed swirling flow rectified by the swirl chamber becomes a uniform high-speed swirl flow from the annular gas injection port. It is injected in a tapered conical shape toward the front of the injection port. The powder that is sucked by the ejector action of the air flow in the nozzle and is primarily dispersed is contacted with the high-speed vortex formed outside the nozzle as soon as it is ejected from the powder ejection port, and is secondarily dispersed to The particles constituting the body have the original size, and it is possible to achieve highly efficient dispersion, which was difficult with conventional powder nozzles.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a powder nozzle which is an embodiment of the present invention.

FIG. 2 is a core for forming a swirl guide hole and a swirl chamber, which are essential parts of the powder nozzle.

FIG. 3 is a front view of the main part of the powder nozzle.

FIG. 4 is an enlarged cross-sectional view around the swirl chamber.

FIG. 5: Particle size distribution characteristic diagram of a conventional powder nozzle

FIG. 6 is a particle size distribution characteristic diagram of the powder nozzle of this embodiment.

FIG. 7 is an overall configuration diagram of a particle size distribution measuring device to which the nozzle of this embodiment is applied.

[Explanation of symbols]

 10 Nozzle body 17 Powder supply hopper 22 Swirling guide hole 24 Vortex chamber A Powder injection port B Gas injection port

Claims (2)

[Claims] 1. A powder injection port through which powder that is negatively sucked by the ejector action of the air flow is injected together with the air flow, an annular swirl chamber formed at a position where the powder injection port is engaged, and a spiral shape. A plurality of swirl guide holes that extend into the swirl chamber and introduce a high-speed airflow into the swirl chamber so as to generate a high-speed swirl flow in the swirl chamber; and a front side of the powder jet port on the side of the swirl chamber facing the powder jet port. And a ring-shaped gas injection port for forming a tapered conical high-speed vortex flow having a focal point in front of the powder injection port, and a powder nozzle. 2. A diffusion cylinder having a cylindrical shape having an outside air suction hole formed on an outer side thereof and accelerating a powder dispersion action of a high-speed vortex formed from a gas injection port is attached to a front end portion of the nozzle. The powder nozzle according to claim 1, wherein