Efficient dispersion powder feeding device for plasma spheroidizing system

Abstract

The utility model discloses an efficient dispersion powder feeding device for a plasma spheroidizing system, which comprises a conveying pipe, a reducer pipe and a dispersion plate are arranged on the inner side of the conveying pipe, and the reducer pipe is arranged above the dispersion plate; the outer side of the conveying pipe is sleeved with a middle pipe, the outer side of the middle pipe is provided with an outer pipe, the inner side of the outer pipe and the outer side of the conveying pipe form an annular space, the middle pipe divides the annular space into an inner cavity and an outer cavity, and one end of the inner cavity is communicated with one end of the outer cavity; by arranging the reducer pipe and utilizing the structural characteristic that the two ends of the inner side of the reducer pipe are wide and the middle of the inner side of the reducer pipe is narrow, the section of a powder flowing channel is changed, meanwhile, under the action of the reducer pipe, powder particles are forced to fall at differential speed, and in addition, falling powder falls into a plasma area through dispersion of the dispersion plate again. And support is provided for improving the heat transfer efficiency of the plasma and the powder.

Description

Technical Field

[0001] The utility model relates to the technical field of powder spheroidization and powder feeding, in particular to a high-efficiency dispersed powder feeding device for a plasma spheroidization system. Background Art

[0002] Radio frequency induction plasma spheroidization technology is to ionize the working gas to generate high temperature and high enthalpy plasma, and then send the powder into the high temperature zone of the plasma through the powder feeding assembly to melt and condense into spherical droplets under surface tension, and then cool and solidify in the cooling chamber to obtain high sphericity powder. Compared with other spherical powder preparation technologies such as gas atomization, plasma rotating electrode, plasma atomization, etc., it has the advantages of high powder sphericity, high density, high purity, and easy control of particle size. It has great advantages in the preparation of spherical metal powders, especially refractory metals and spherical ceramic powders. With the rapid development of additive manufacturing technology in recent years, the market demand for high-performance spherical powders is also increasing.

[0003] Specifically, when using a plasma generator to spheroidize powder, a powder feeding pipe needs to be installed through the hole reserved above the plasma generator. The top of the powder feeding pipe is connected to the powder feeder through a hose. Under the action of the powder feeder, the powder descends along the powder feeding pipe and falls into the high-temperature area created by the plasma generator. After melting, the powder is spheroidized under the action of surface tension.

[0004] However, there are some problems in the large-scale production of plasma spheroidization, among which the most prominent problem is the low production efficiency. Usually, the powder feeding gun used in the plasma spheroidization device is a straight metal tube. When the powder falls in the straight metal tube, it will gather together, resulting in poor dispersion of the powder in the plasma, making it impossible for the powder to fully absorb heat and melt, greatly reducing the heat utilization efficiency in the plasma, causing some powders to fail to spheroidize, resulting in low production efficiency. Utility Model Content

[0005] The utility model aims to provide a high-efficiency dispersing powder feeding device for a plasma spheroidization system, aiming to improve the problem that the powder has poor dispersion in plasma and affects the production efficiency of plasma spheroidization.

[0006] The utility model is implemented as follows: a high-efficiency dispersed powder feeding device for a plasma spheroidization system comprises a conveying pipe, a reducer and a dispersion plate are arranged on the inner side of the conveying pipe, and the reducer is arranged above the dispersion plate; an intermediate pipe is sleeved on the outer side of the conveying pipe, and an outer pipe is arranged on the outer side of the intermediate pipe, and the inner side of the outer pipe and the outer side of the conveying pipe form an annular space, and the intermediate pipe divides the annular space into inner and outer cavities, and one end of the inner cavity is connected with one end of the outer cavity.

[0007] Preferably, the inner ends of the reducer are wide and the middle is narrow, and the outer wall is in contact with the inner wall of the conveying pipe; more than one reducer is provided and distributed up and down.

[0008] Preferably, the dispersion plate is configured as a disc structure, and the outer side wall is in contact with the inner side wall of the conveying pipe, and a plurality of through holes are provided on the dispersion plate.

[0009] Preferably, the optimal powder dispersion effect of different powders in the plasma is achieved by changing the size and position of the reducer and the dispersion plate.

[0010] Compared with the prior art, the utility model has the following beneficial effects: the utility model is provided with a reducer, and utilizes the structural characteristics of the inner ends being wide and the middle being narrow to change the cross-section of the powder flow channel; at the same time, under the action of the reducer, the powder particles are forced to fall at a differential speed, and the falling powder is dispersed again by the dispersion plate and falls into the plasma area, providing support for improving the efficiency of heat transfer between plasma and powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the first three-dimensional structure of an embodiment of the utility model;

[0012] Figure 2 It is a schematic cross-sectional structure diagram of an embodiment of the utility model.

[0013] In the figure: 1, conveying pipe; 2, reducing pipe; 3, dispersion plate; 4, intermediate pipe; 41, first flow pipe 42; 5, outer pipe; 51, second flow pipe. DETAILED DESCRIPTION

[0014] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0015] The following is a further description with reference to the accompanying drawings and specific embodiments:

[0016] like Figure 1-2As shown, a high-efficiency dispersed powder feeding device for a plasma spheroidization system includes a conveying pipe 1, an intermediate pipe 4 and an outer pipe 5. The outer pipe 5 is sleeved on the outside of the conveying pipe 1, and the intermediate pipe 4 is arranged between the conveying pipe 1 and the outer pipe 5, and the annular space formed by the outer pipe 5 and the conveying pipe 1 is divided into inner and outer cavities. One end of the inner cavity and the outer cavity are connected, and the other end is respectively provided with a first flow pipe 42 and a second flow pipe 51. The first flow pipe 42 and the second flow pipe 51 serve as the inlet and outlet of cooling water, respectively. The cooling water enters the annular space from the inlet, and flows from the inner cavity to the outer cavity, or flows from the outer cavity to the inner cavity, and finally is discharged from the outlet. In the process of cooling water circulation, the heat of the conveying pipe 1 is taken away, thereby cooling the high-temperature and spheroidized powder. The inner side of the conveying pipe 1 is provided with a channel for carrier gas and powder, and the inner diameter is 2-8mm.

[0017] When the device is used in a plasma spheroidization system, the delivery pipe 1 is installed at the reserved hole above the plasma generator and penetrates the plasma high temperature area of ​​the plasma generator. The delivery pipe 1 penetrates into the high temperature area to facilitate the condensation of the powder into a spherical liquid. The spheroidized powder falls and is cooled and solidified in a cooling chamber with water cooling, thereby obtaining a powder with high sphericity. In order to make the powder fall along the delivery pipe 1, the top of the delivery pipe 1 is connected to the powder feeder through a hose, and the powder is transported to the delivery pipe 1 under the action of the powder feeder. In order to control the circulation of cooling water, the cooling water is pressurized and circulated into the annular space by a booster pump. In addition, the pressure of the cooling water in the annular space should be greater than 1.5Mpa, and the cooling water uses pure water with a conductivity of less than 10μS / cm.

[0018] In order to enable the powder to disperse and move in the conveying pipe 1, a reducer 2 and a dispersion plate 3 are arranged on the inner side of the conveying pipe 1, and the reducer 2 is arranged above the dispersion plate 3. The inner ends of the reducer 2 are wide and narrow in the middle, and the outer wall contacts the inner wall of the conveying pipe 1. In addition, two reducers 2 are arranged and distributed up and down. Under the action of the reducer 2, the cross section of the powder flow channel can be changed. At the same time, under the action of the reducer 2, the powder particles are forced to fall at a differential speed, which provides support for improving the efficiency of heat transfer between plasma and powder. The dispersion plate 3 is set as a disc structure, and the outer wall contacts the inner wall of the conveying pipe 1. A plurality of through holes are arranged on the dispersion plate 3. The falling powder is dispersed again under the action of the dispersion plate 3, and the difference in the falling of the powder particles is increased, which provides support for further improving the efficiency of heat transfer between plasma and powder. The dispersion plate 3 is arranged above the plasma area, so the powder falling through the dispersion plate 3 falls into the plasma area, and the powder is dispersed and falls. The reducer 2 is composed of a contraction section, a parallel section and an expansion section, the contraction section angle is 5-60°, the parallel section diameter is 2-7mm, the parallel section length is 1-20mm, and the expansion section angle is 5-60°. The dispersion plate 3 can be set as a circular hole with an aperture of 0.5-3mm or a square hole with a side length of 0.5-3mm.

[0019] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be modified and varied in various ways. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An efficient dispersing powder feeding device for a plasma spheroidization system, characterized in that: The invention comprises a conveying pipe (1), wherein a reducing pipe (2) and a dispersion plate (3) are arranged on the inner side of the conveying pipe (1), wherein the reducing pipe (2) is arranged above the dispersion plate (3); an intermediate pipe (4) is sleeved on the outer side of the conveying pipe (1), and an outer pipe (5) is arranged on the outer side of the intermediate pipe (4); the inner side of the outer pipe (5) and the outer side of the conveying pipe (1) form an annular space; the intermediate pipe (4) divides the annular space into inner and outer cavities, wherein one end of the inner cavity is connected to one end of the outer cavity.

2. The high-efficiency dispersed powder feeding device for a plasma spheroidization system according to claim 1, characterized in that: The inner ends of the reducer (2) are wide and narrow in the middle, and the outer wall contacts the inner wall of the delivery pipe (1); two reducers (2) are provided and are distributed up and down.

3. The high-efficiency dispersed powder feeding device for a plasma spheroidization system according to claim 2, characterized in that: The dispersion plate (3) is configured as a disc structure, and the outer wall thereof is in contact with the inner wall of the conveying pipe (1), and a plurality of through holes are provided on the dispersion plate (3).

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