JPH06278030A - Nozzle for solid-liquid multiphase flow - Google Patents

Abstract

PURPOSE:To prevent abrasion caused by collision of a solid phase onto the wall surface of a nozzle by forming an orifice by which the sectional area of the nozzle at which the axis of the nozzle is cut by a plane perpendicular thereto is gradually decreased from the inlet to the outlet of the nozzle, and forming an area where no particles exist that extends from the orifice minimum- diameter portion to the outlet. CONSTITUTION:In a nozzle 1 which allows a solid-liquid multiphase flow to pass therethrough at high speed, an orifice 4 by which the sectional area of the nozzle 1 at which the axis of the nozzle 1 is cut by a plane perpendicular thereto is gradually decreased from the inlet 2 to the outlet 3 of the nozzle 1 is formed, so as to form an area where no particles exist that extends from the orifice minimum-diameter portion to the outlet 3. The inlet 2 is formed by e.g. a 1-mm line and the sectional area of the line is gradually decreased to an orifice diameter of 0.3mm within a line length of 0.52mm. As a result, abrasion that could be caused by collision of the solid phase on the wall surface of the nozzle can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle used for a solid-liquid mixed phase flow, and more particularly to a nozzle through which a fluid passes at a high speed.

[0002]

2. Description of the Related Art Machining of high-hardness cemented carbide is carried out by electrical discharge machining or grinding. However, in the method of electrical discharge machining, the material near the machined part is adversely affected by heat due to electrical discharge, or grinding is performed. The method of 1 has a problem that strain is generated by mechanical stress.

Therefore, processing by a water jet for injecting ultra-high pressure water is performed. Since the water jet is processed by the jetting energy of water, it may be difficult to process with a material having a high degree of altitude. Therefore, in the method using a water jet, for a material that is difficult to process such as cutting, an abrasive water jet in which an abrasive is mixed in a high-pressure jet stream is used.

FIG. 4 is a diagram showing an example of a nozzle for an abrasive water jet. High pressure water is introduced into the mixing chamber 11 through the water nozzle 12, and the negative pressure generated in the mixing chamber causes the abrasive 1 to flow from the abrasive inlet 13.
4 is sucked and ejected from the nozzle 15 together with high-speed water, so that the member to be processed is cut or ground. Even if the nozzle is made of a material with high hardness, the high-pressure fluid mixed with the abrasive passes through the nozzle, causing large wear damage,
The nozzle had to be replaced frequently.

In the manufacturing process of paints, pigments, inks, pharmaceuticals, photosensitive materials, magnetic recording media, etc., an emulsifying apparatus is used to disperse and homogenize liquids and fine particles as a raw material. In order to obtain a material having a high degree of dispersion, various devices have been proposed that emulsify and disperse by a method such as ejecting a high-pressure fluid from a nozzle and causing the fluid to collide. With such a device, it is possible to obtain a highly emulsified and dispersed fluid, but there is a problem with the durability of the nozzle, and it was necessary to replace the nozzle in a short time depending on the composition of the fluid.

[0006]

DISCLOSURE OF THE INVENTION The present invention uses a fluid as a nozzle through which a solid-liquid multiphase flow passes at a high speed, which is used for an abrasive water jet nozzle mixed with an abrasive, an emulsification dispersion nozzle, and the like. It is an object of the present invention to provide a nozzle that is less likely to be worn and damaged by a flow.

[0007]

According to the present invention, in a nozzle through which a high-speed solid-liquid mixed phase flow passes, the area of a cross section obtained by cutting the central axis of the nozzle by a vertical plane is gradually reduced from the inlet side of the nozzle toward the outlet side. It is a nozzle for solid-liquid mixed phase flow, in which the formed orifice is formed and a particle-free region is formed from the minimum orifice diameter portion to the outlet side. That is, in the conventional nozzle, as shown in FIG. 4, the flow path is formed of a pipe line having a constant cross-sectional area. In such a nozzle, the inner surface of the nozzle was abraded early by the abrasive material.However, in the nozzle of the present invention, the orifice is provided in the nozzle through which high-speed fluid passes and the minimum cross-sectional area of the orifice is cut. By gradually reducing the area, the surrounding flow velocity decreases as compared to the flow velocity at the center of the fluid that has passed through the orifice,
A region where no particles exist is generated in the nozzle. Then, the inventors have found that by forming the wall surface of the nozzle along the boundary particle streamline between the portion where the particles are present and the portion where the particles are not present, a nozzle in which the wall surface of the nozzle is not worn can be obtained.

[0008]

[Function] Since only the liquid phase exists in contact with the wall surface of the nozzle and the wall surface is provided in the area where the solid phase does not exist, the nozzle is used for a long period of time without abrasion damage due to the abrasive in the liquid on the wall surface. can do.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of the nozzle of the present invention.
The nozzle 1 has an orifice 4 between the inflow side 2 and the outflow side 3.
Is formed, and the cross-sectional area of the conduit gradually decreases toward the orifice 4. In this example, the size of the inflow side is 1 mm
The cross-sectional area of the conduit is gradually reduced to an orifice diameter of 0.3 mm during the length of 0.52 mm.

FIG. 2 shows the shape of the cross section of the nozzle shown in FIG. 1 and the boundary particle streamline in which a particle-free region is formed by the orifice. Shows the length of the nozzle, and the vertical axis shows the diameter of the conduit having an orifice radius of 1. Since a portion where particles do not exist is formed on the outlet side of the orifice of the nozzle, the wear of the nozzle can be prevented by forming the wall surface at a position farther from the central axis than the boundary particle streamline.

FIG. 3 is a diagram showing isomach lines in the vicinity of the orifice of the dispersion liquid in which the particles are dispersed. The horizontal axis represents the minimum orifice radius of 1 and the minimum orifice diameter is the origin. The vertical axis indicates the nozzle diameter with the radius of the orifice being 1. In addition, a dotted line shows an equal Mach line. 2 garnets for abrasives in water
The solid-liquid two-phase flow mixed with 0% by weight is at 20 ° C.

[0012]

The solid-liquid mixed phase flow nozzle of the present invention has a specific orifice formed in the nozzle. Therefore, only the liquid phase exists on the wall surface of the nozzle downstream of the orifice, and there is a region where the solid phase does not exist. Since it is formed, the nozzle can be used for a long period of time without causing wear damage due to the solid phase on the wall surface.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a nozzle of the present invention.

FIG. 2 is a diagram illustrating a cross-sectional shape of a nozzle shown in FIG. 1 and a boundary particle streamline.

FIG. 3 is a diagram illustrating isomach lines of a solid-liquid mixed phase flow containing an abrasive.

FIG. 4 is a sectional view showing an example of a conventional abrasive nozzle.

[Explanation of symbols]

1 ... Nozzle, 2 ... Inflow side, 3 ... Outflow side, 4 ... Orifice, 11 ... Mixing chamber, 12 ... Water nozzle, 13 ... Abrasive inlet, 14 ... Abrasive, 15 ... Nozzle

Claims (1)

[Claims] 1. In a nozzle through which a high-speed solid-liquid mixed-phase flow passes, an orifice is formed by gradually reducing the area of a cross section of the central axis of the nozzle taken along a plane perpendicular to the nozzle from the inlet side to the outlet side. A nozzle for solid-liquid mixed phase flow, characterized in that a particle-free region is formed from the orifice diameter portion to the outlet side.