CN100500337C

CN100500337C - Quadratic accelerating ultrasonic nebulization jet nozzle system for preparing copper powder

Info

Publication number: CN100500337C
Application number: CNB2007101027800A
Authority: CN
Inventors: ***; 孙康; 黄开启
Original assignee: Jiangxi University of Science and Technology
Current assignee: Jiangxi University of Science and Technology
Priority date: 2006-06-16
Filing date: 2007-04-28
Publication date: 2009-06-17
Anticipated expiration: 2027-04-28
Also published as: CN101062523A

Abstract

The copper powder secondary supersonic atomization nozzle system with the inlet of the inner hole formed into tapering shape and connecting with the top of the tapering shape, at least two compression cover bosses. The long conical shape of the rear of the nozzle allows the copper fluid contracted by the air flow attraction, storing the energy, spraying finer grains. The atomized media reaches supersonic speed after secondary speeding up, spraying out from the isolation expansion, acquiring great media speed and energy, strengthening crushing force, with finer powder particles. It can separate the machining of the nozzle and the compression cover with simple process and convenient installation.

Description

The quadratic accelerating ultrasonic nebulization jet nozzle system of preparation copper powder

Affiliated technical field

The present invention relates to a kind of atomizing and prepare employed nozzle of copper powder and gland, especially prepare the quadratic accelerating ultrasonic nebulization jet nozzle system of copper powder.

Background technology

In non-ferrous metal, the output of copper powder and consumption are in continuous increase, especially the refinement copper powder of granularity more than 400 orders (diameter 38 μ m), its demand obviously strengthens especially in recent years, and the above refinement copper powder of 400 orders also is that present China copper powder is produced and application and development trend.

The method of domestic production copper powder has electrolysis, gas reduction method, atomization etc.Electrolysis need consume a large amount of electric energy, and powder activity is big, needs reduction to handle, the cost height, and unsuitable production of copper base alloy powder, and also a large amount of waste electrolytes also needs to handle again, otherwise pollute the environment; Gas reduction method price height, powder-product purity is subjected to directly influencing of material purity, also should not produce copper-base alloy powder; Also having gas evaporation method, plasma method, mechanochemistry method, gamma-ray irradiation in addition---hydrothermal crystallization integrated processes etc., the copper nanoparticle price of its production are extremely expensive, make demander hang back.

Atomization is present most widely used metal milling method, and the atomization process of metal is very complicated, relates to many factors, and is very high to the specification requirement of powder size and Properties Control, and wherein nozzle and gland are that one of critical component of high-quality copper powder is obtained in atomizing.According to theoretical research and practical experience, good atomizer system should meet the following conditions: 1, atomizing medium can obtain big as far as possible muzzle velocity and energy.2, can form the rational ejector angle between atomizing medium and the metal liquid stream.3, metal liquid stream can produce maximum turbulent flow.4, guarantee the iptimum speed of atomizing medium muzzle velocity and metal liquid stream, also have Optimal Control metal liquid stream flow.5, good operating stability does not get clogged.6, processing and manufacturing is simple.The nozzle that generally adopts is that endoporus is the shrinkage type nozzle of truncated cone-shaped and the nozzle endoporus exit portion of No. 63470 announcements of RUSSP is single enlarging nozzle of bellmouth at present, endoporus shrinkage type nozzle reduces the copper flow quantity, flow velocity increases, help the pulverizing of copper liquid, but because copper liquid is not very big in the speed of nozzle exit, so the original drop that forms is big or a fluid stream is thicker, has increased difficulty to pulverizing, and it is thicker to cause dusting; The copper powder quality ratio that adopts single enlarging nozzle to obtain uses the height of endoporus shrinkage type nozzle, but atomizing effect is still not really desirable.The medium channel that the structure of gland is designed between gland and nozzle forms the contracted channel (Lavalle type) that the cross section is littler in nearly exit, atomizing medium can be realized once quickening in contracted channel, for making atomizing medium that higher flow velocity and kinetic energy be arranged, crush force also further strengthens, and can obtain superfine powder.The author finds after deliberation, makes thin copper powder, and adopting the supersonic gas atomizing is optimal selection, and resulting powder is more concentrated.The degree of grinding of atomized liquid stream is relevant with dynamic viscosity coefficient and temperature flow, improve temperature and can reduce dynamic viscosity coefficient, but improving temperature can increase scaling loss, reduces yield rate.Most of metallic surface tension force reduces along with the rising of temperature, but except two kinds of metals, a kind of is exactly copper, is advisable so select the copper liquid degree of superheat to be 200 ℃.Under constant metal liquid stream, the muzzle velocity that improves atomization gas is to improve the key of atomizing ability.Though the Lavalle type can obtain supersonic speed, speed still is short of.

Summary of the invention

The object of the present invention is to provide a kind of metal liquid stream that can make to produce bigger turbulent flow, atomizing medium can obtain the quadratic accelerating ultrasonic nebulization jet nozzle system of the preparation copper powder of secondary acceleration.

The technical solution adopted for the present invention to solve the technical problems is: this atomizer system comprises nozzle 1 and gland 2, the interior hole exits 7 of nozzle 1 is a taper type, 2 on nozzle 1 and gland form a medium channel 3, be provided with a boss structure A5 in the gland 2, taper type is also made in the import 6 of its nozzle 1 endoporus, and the vertex of a cone of import 6 and outlet 7 frustums also connects; Boss structure in the gland 2 has two at least.The length of import 6 frustums is longer than outlet 7 frustums; The tapering of import 6 frustums is greater than the tapering of outlet 7 frustums.The drift angle of nozzle 1 is 45 degree.The drift angle of boss structure A5 is 40 degree, and the drift angle of other boss structure increases gradually.

The invention has the beneficial effects as follows that through reaching supersonic speed after the secondary acceleration, adiabatic expansion ejection then makes atomizing medium obtain great muzzle velocity and energy needed to (1) atomizing medium in runner, crush force is strengthened, and can obtain thinner powder.

(2) reduced the angle of cut between atomizing medium and metal liquid stream, jet apex angle is designed to 45 degree, has increased the distance between atomizing medium spout and metal liquid stream axis, circumferential weld width suitable (1mm), and the circumferential weld gap is even.Guaranteed to form between atomizing medium and the metal liquid stream iptimum speed of angle with rational and atomizing medium muzzle velocity and metal liquid stream, nozzle is difficult for stopping up, good operating stability

(3) copper liquid is along spraying in the pipe that is close to the Lavalle type, because adiabatic expansion, copper liquid density diminishes, enlarge the turbulent region, increased amount of turbulence, make metal liquid stream produce maximum turbulent flow, also increased simultaneously the angle of cut of atomizing medium and copper liquid stream, thereby increased the pulverizing number of times of atomizing medium copper liquid.

(4) native system is made up of nozzle and gland two parts, and adding man-hour can separate machined, and processing technology is simple, easy installation and removal.

Description of drawings

The present invention is further described below in conjunction with drawings and Examples.

Fig. 1 is a cutaway view of the present invention.

1. nozzles among the figure, 2. gland, 3. medium channel, 4. boss structure B, 5. boss structure A, 6. import, 7. outlet.

The specific embodiment

Nozzle 1: the Design of length of import 6 frustums becomes than 2.75 times that export 7 frustums, and the tapering of import 6 frustums is 1: 2.2, and the tapering that exports 7 frustums is 1:4.The angle of nozzle 1 and vertical direction, promptly drift angle is designed to 45 degree.

Gland 2: gland 2 inboard designs have two boss structures, the angle of boss structure A5 and vertical direction, and promptly drift angle is designed to 40 degree, the angle of boss structure B4 and vertical direction, promptly drift angle is designed to 54 degree.

Nozzle material is selected the Cf/SiC composite, and heat-insulating material and protective jacket are selected to make the refractory composite heat-insulated material by the FRC1-12 of 22% aluminium borate fiber.

Gland 2 is enclosed within on the

nozzle

1,2 on nozzle 1 and gland form a medium channel 3, medium channel 3 forms contracted channel at boss structure B4 and boss structure A5 place, contracted channel begins at boss structure B4 place, its channel cross-section dwindles gradually, the channel cross-section minimum enlarges gradually along the exit then during to boss structure A5 place.Copper liquid stream sprays from the nozzle endoporus, because import 6 is conical, and cone is longer, therefore, when moving therein, copper liquid stream compressed by air-flow suction, energy is stored, reach maximum when exporting 7 places, expand outwardly again, promptly compress afterwards earlier and expand, because its speed is very big and the vibration of compressed air ripple, copper liquid stream wavyly flows forward and is dispersed into many droplets or thin fibre bundle with unsettled, even residual copper liquid stream may to be dispersed into all that the fine fibre bundle travels forward in the middle of causing along the enlarging wall be a space, when fine fibre bundle and droplet arrive near " atomizing focus ", be dispersed into littler drop by airflow scouring, the granularity of dusting is attenuated.And medium channel 3 ejections that atomizing medium forms from nozzle 1 and gland 2, atomizing medium is through boss structure B4 and boss structure A5, the long-pending secondary of cross section of fluid channel reduces to enlarge then, atomizing medium realizes that secondary quickens, adiabatic expansion reaches supersonic speed then, below nozzle, act on copper liquid stream with great speed and energy, directly smash liquid copper and obtain superfine cupper powder.

Claims

1. quadratic accelerating ultrasonic nebulization jet nozzle system for preparing copper powder, comprise nozzle (1) and gland (2), the interior hole exits (7) of nozzle (1) is a taper type, form a medium channel (3) between nozzle (1) and gland (2), be provided with a boss structure A (5) in the gland (2), it is characterized in that taper type is also made in the import (6) of its nozzle (1) endoporus, the vertex of a cone of import (6) and outlet (7) frustum also connects; Boss structure in the gland (2) has two at least.

2. the quadratic accelerating ultrasonic nebulization jet nozzle system of preparation copper powder according to claim 1 is characterized in that: the length of import (6) frustum is longer than outlet (7) frustum; The tapering of import (6) frustum is greater than the tapering of outlet (7) frustum.

3. the quadratic accelerating ultrasonic nebulization jet nozzle system of preparation copper powder according to claim 1 is characterized in that: nozzle (1) is 45 degree with the angle of vertical direction.

4. the quadratic accelerating ultrasonic nebulization jet nozzle system of preparation copper powder according to claim 1 is characterized in that: boss structure A (5) is 40 degree with the angle of vertical direction, and the angle of other boss structure and vertical direction increases gradually.