Installation for plasma-chemical recovery of metal oxides
The invention relates to powder metallurgy and can be used to obtain powders of metal oxides. In the proposed installation comprising a device for loading raw materials, plasmogenerator, the reactor, the precipitation chamber, the filter and the collected powder according to the invention the precipitation chamber, at least two communicating sections with decreasing cross-section in place of their connection to education pinches the gas stream, one of the sections in the upper part is connected with the reactor, the other with a filter, and in the lower part of the section is made as a separate tapered pockets in the bottom part connected collections of powder. Provides high reliability, performance, installation and production of metal powder of high quality. 4 C.p. f-crystals, 1 Il.
The invention relates to powder metallurgy, in particular to installations for plasma-chemical recovery of metal oxides.
The known installation for producing granules by spraying bar stock (U.S. patent No. 3752610, NCI 425-6, 1973, RF patent №688282, MKI 22 D 23/08, 1977). Used heaters in these installations do not allow pererabativat the provide obtain fine granules. To increase the dispersion of the granules should additionally be processed in high-temperature gas stream.
Known device for heat treatment of particulate materials in high-temperature gas flow containing working chamber with plasma torches. In the upper part of the working chamber above the burner is a device for introducing a plasma-forming gas, and the lower part is the collection of the finished product (as the USSR №558758, MKI 22 F 9/14, 1975).
Known installation for plasma-chemical recovery of metal oxides containing a device for loading raw materials, plasmogenerator, the reactor, the precipitation chamber, the filter and the collected powder (Cypress S. S. and other Equipment, powder metallurgy. - M.: metallurgy, 1988, S. 56-58), selected for the nearest equivalent.
The disadvantage of this installation should include low productivity and lack of reliability.
The technical task of the invention is to improve the performance and reliability of the plant, as well as providing the possibility of producing metal powder of a higher quality.
The task is solved in that the installation comprising a device for loading raw materials, plasmagene saudies section with a reduced cross-section at their point of connection, one of which is in the upper part is connected to the reactor, and the other with a filter, and in the lower part of the section is made as a separate pockets in the bottom part connected collections of powder.
The problem is solved also by the fact that the reactor and the filter is installed on the upper part of the sedimentation chamber, the reactor and the filter can be installed vertically.
The problem is solved also by the fact that it is equipped with a control unit of the presence of hydrogen, and the monitoring unit installed on the outlet port of the filter in its upper part, and can also be accomplished by visual observation.
Installation for plasma-chemical recovery of metal oxides (see drawing) contains a device for loading of raw material, made in the form of four boot dispensers 1, plasmogenerator 2 mounted on the reactor 3, and the precipitation chamber 4.
Settling chamber 4 consists of two inter-connected sections 5 and 6. Sections 5 and 6 in the upper part is connected to the reactor 3 and the filter 7, respectively. Sections 5 and 6 of the collecting chamber 4 is performed with the reduced cross sections in 8 of their connection with the formation pinches on the path of gas flow from section 5 to section 6 in the upper part of the sedimentation chamber. part connected collections of powder 11, 12. On the top cover 13 of the filter 7 at the outlet port 14 has a control unit of the presence of hydrogen 15 made in the form of candles burning hydrogen with visual observation of her.
The device operates as follows.
Connected to a power source (not shown) plasmogenerator 2 forms a plasma jet in the axial direction of the reactor 3.
As a plasma-forming gas use reduction gas, for example hydrogen.
From the boot of dispensers 1, the oxide powder of the metal is directed into the plasma jet, where the evaporation of metal oxide and its restoration to the metal in the gas phase. A pair of metal condensed in the form of a (small) particles in the lower part of the reactor 3. The condensate in the form of larger particles of the powder is collected in the first along the gas flow sections 5 and is deposited in the pocket 9, smaller particles are entrained by the gas stream through like 8 in section 6 and deposited on the filter 7. The filter 7 provided with a device 16 for periodic shaking the powder. When shaken, the fine particles are deposited in the pocket 10 collecting chamber 4. Thus, the metal particles are separated according to mass and going in the collections of the powder 11, 12, respectively.
When the installation athrabeth.
The presence of hydrogen in a precipitation chamber 4 is determined visually by the presence of a flame at the node 15 control the presence of hydrogen. Monitoring the presence of hydrogen provides the reliability of the installation.
Structural features installation by performing the precipitation chamber into two sections allow you to catch the powder to divide it up into fine and coarse fractions, which ensures the quality and productivity of the installation.
1. Installation for plasma-chemical recovery of metal oxides containing a device for loading raw materials, plasmogenerator, the reactor, the precipitation chamber, the filter and the collected powder, wherein the settling chamber is made of at least two interconnected sections with decreasing cross-section in place of their connection to education pinches the gas stream, one of the sections in the upper part is connected with the reactor, the other with a filter, and in the lower part of the section is made as a separate tapering downwards pockets in the bottom part connected collections of powder.
2. Installation under item 1, characterized in that the reactor and the filter installed on ve is monitoring the presence of hydrogen.
4. Installation according to p. 3, characterized in that the control unit of the presence of hydrogen is installed on the outlet port of the filter at the top.
5. Installation according to p. 3, characterized in that the control unit of the presence of hydrogen made with visual observations.
FIELD: production of powders by electric explosion of wire.
SUBSTANCE: installation includes reactor for electric explosion of wire with high-voltage and low-voltage electrodes that are connected to pulse current sources; mechanism for feeding wire to reactor; gas and powder circulation system; unit for separating gas and accumulating powder. According to invention gas and powder circulation system is in the form of tubular gas discharging pipes communicated by their one ends with reactor in front of inter-electrode gap and by their other ends - with unit for separating gas and accumulating powder. Said unit is in the form of successively connected through branch pipes expanders. Each expander is provided with powder accumulator at providing relation Si/Si+1 ≥ 1.43 where i = 1, 2…, Si - total surface area of effective cross section of tubular gas discharging pipes; S2, S3 - surface area of connection branch pipes.
EFFECT: enhanced quality of product due to lowered agglomeration of powder.
2 dwg, 2 tbl
FIELD: production of nanodispersed powders of refractory inorganic materials and compounds, in particular, installations and methods for realization of plasmochemical processes of production of nanodispersed powder products.
SUBSTANCE: the installation comprises production-linked: microwave oscillator 1, microwave plasmatron 2, gas-flow former 3, discharge chamber 4, microwave radiation absorber 5, reaction chamber 6, heat-exchanger 7, filter-collector of target product (powder) 8, device for injection of the source reagents in a powdered or vapors state into the reaction chamber, the installation has in addition a device for injection of the source reagents in the liquid-drop state, it has interconnected proportioner 9 in the form of cylinder 10, piston 11 with gear-screwed electric drive mechanism 12 adjusting the speed of motion of piston 1, evaporative chamber 13 with a temperature-controlled body for regulating the temperature inside the chamber that is coupled to the assembly of injection of reagents 14 in the vaporous state and to the assembly of injection of reagents 15 in the liquid-drop state, injection assembly 14 is made with 6 to 12 holes opening in the space of the reaction chamber at an angle of 45 to 60 deg to the axis of the chamber consisting at least of two sections, the first of which is connected by upper flange 16 to the assemblies of injection of reagents, to discharge chamber 4, plasmatron 2, with valve 17 installed between it and microwave oscillator 1, and by lower flange 18, through the subsequent sections, it is connected to heat exchanger 7, the reaction chamber has inner water-cooled insert 20 rotated by electric motor 19 and metal scraper 21 located along it for cutting the precipitations of powder of the target product formed on the walls of the reaction chamber, and heat exchanger 7 is made two water-cooled coaxial cylinders 22 and 23, whose axes are perpendicular to the axis of the reaction chamber and installed with a clearance for passage of the cooled flow, and knife 24 located in the clearance, rotating about the axis of the cylinders and cleaning the working surfaces of the cylinders of the overgrowing with powder, powder filter-collector 8 having inside it filtering hose 25 of chemically and thermally stable material, on which precipitation of powder of the target product from the gas flow takes place, in the upper part it is connected by flange 26 to the heat exchanger, and in the lower part the filter is provided it device 27 for periodic cleaning of the material by its deformation, and device 28 with valve 29 for sealing the inner space of the filter. The method for production of nanodispersed powders in microwave plasma with the use of the claimed installation consists in injection of the source reagents in the flow of plasma-forming gas of the reaction chamber, plasmochemical synthesis of reagents, cooling of the target product and its separation from the reaction chamber through the filter-collector, the source reagents are injected into the flow of plasma-forming gas, having a medium-mass temperature of 1200 to 3200 K in any state of aggregation: vaporous, powdered, liquid-drop or in any combination of them, reagents in the powdered state are injected in the form of aerosol with the gas-carrier into the reaction chamber through injection assembly 35 with a hole opening into the space of the reaction chamber at an angle of 45 to 60 deg to the chamber axis, reagents in the liquid-drop or vaporous state are injected into the reaction chamber through injection assemblies 15 or 14, respectively, in the form of ring-shaped headers, the last of which is made with 6 to 12 holes opening into the space of the reaction chamber at an angle of 45 to 60 deg to the chamber axis, each of them is blown off by the accompanying gas flow through the coaxial ducts around the holes, at expenditure of the source reagents, plasma-forming gas, specific power of microwave radiation, length of the reaction zone providing for production of a composite system and individual substances with preset properties, chemical, phase composition and dispersity.
EFFECT: universality of the industrial installation, enhanced capacity of it and enhanced duration of continuous operation, as well as enhanced yield of nanodispersed powders and expanded production potentialities of the method.
20 cl, 1 dwg, 4 ex
FIELD: powder metallurgy, namely apparatuses for producing powders of electrically conducting materials.
SUBSTANCE: apparatus includes dielectric vessel with opening in lower portion for supplying working liquid in it, additional bottom of dielectric material made of mutually parallel rods or prisms, plate-type electrodes connected with electric pulse generator. In order to decrease breakdown voltage of inter-electrode gap apparatus includes three plate electrodes connected in parallel with electric pulse generator and movable dielectric blinds covering electrodes for controlling electric current density. Mean electrode serves as cathode; boundary electrodes serve as consumable anodes.
EFFECT: enhanced efficiency, lowered specific energy consumption, improved stability of process.
3 dwg, 1 tbl, 1 ex
FIELD: powder metallurgy, namely process for producing sub-micron and nanometer size aluminum powder by plasma evaporation.
SUBSTANCE: plasma-arc reactor for producing powder of solid material such as wire includes first electrode and second electrode that may be spaced from first electrode by distance sufficient for plasma arc occurring in space between first and second electrodes. First electrode has duct passing through it; outlet opening of said duct is open to space between first and second electrodes. Reactor includes unit for feeding solid material such as wire through said duct into space between electrodes. If it is necessary to produce passivated aluminum powder, in reactor aluminum wire is fed to inert-gas plasma where aluminum evaporates. Evaporated aluminum is cooled by inert gas for condensing aluminum powder and oxidizing surface of aluminum powder particles with passivating gas.
EFFECT: enhanced efficiency, possibility for producing fine powders of highly constant size and small cohesion forces of particles.
46 cl, 8 dwg, 2 tbl, 1 ex
FIELD: powder metallurgy, namely processes for producing metallic and oxide nano-particles.
SUBSTANCE: process comprises steps of placing electrodes in chamber with dielectric liquid; realizing pulse electric discharge between them for generating electric arc; measuring spacing between electrodes for fixing its value; creating flow-through motion of dielectric liquid in chamber; measuring temperature of dielectric liquid at inlet and at outlet of chamber; providing preset temperature range of dielectric liquid at inlet and at outlet of chamber due to changing flow rate of said liquid passing through chamber. Temperature difference of dielectric liquid at inlet and outlet of chamber is no more than 7°C. Invention provides increased quantity of nano-particles with fraction size 5 -50 nm.
EFFECT: enhanced quality of nano-particles.
4 cl, 1 dwg, 1 tbl
FIELD: metallurgy, namely systems for producing metal powders.
SUBSTANCE: apparatus includes housing in the form of working chamber with controlled temperature of certain portion of its wall; unit for creating gaseous medium in volume of working chamber; electric power source; at least two electrodes; unit for continuous supply of dispersed metal. Apparatus includes in addition drive unit for rotating in horizontal plane. Said unit is provided with control circuit and electric power supply system. Working chamber is in the form of built-up sleeve having outer and inner members. Inclination angle (from outside) of wall of outer member is in range 16 - 135° relative to rotation plane. Built-up sleeve is fastened by means of bottom portion of outer member with cooled shaft of drive unit for rotating in horizontal plane. Outer metallic member of built-up sleeve has turning for passing cooling agent. Inner member of built-up sleeve is made of high-temperature ceramic material and it has chamfer formed along upper edge of sleeve. Said chamfer is inclined by angle 2 - 68° relative to rotation plane of sleeve.
EFFECT: automatic sizing of discrete particles of fibers, stable production process.
6 cl, 2 dwg, 3 ex
FIELD: processes for preparing finely and ultra-dispersed powders of metals and alloys.
SUBSTANCE: process comprises steps of electric erosion dispersing metals in working liquid; using as working liquid low electrically conducting electrolytes containing alloying components in the form of solutions of their compounds.
EFFECT: simplified manufacturing process, improved ecological condition of said process, lowered power consumption.
2 dwg, 2 ex
FIELD: inorganic protective coatings.
SUBSTANCE: invention provides preparation of chemically homogeneous powder suitable for thermal spraying. Zirconium dioxide is first subjected to electric fusion using up to 60% by weight of oxide appropriate to stabilize zirconium dioxide in tetragonal phase followed by sharp cooling of thus obtained stabilized zirconium dioxide and heat treatment to form mainly spherical hollow particles of stabilized zirconium dioxide 200 μm or less in size. Powder suitable for applying thermal barrier-forming coating onto a substrate contains morphologically and chemically uniform stabilized zirconium dioxide including spheroidized hollow particles.
EFFECT: optimized preparation process.
7 cl, 5 dwg, 1 tbl
SUBSTANCE: invention relates to powder metallurgy, in particular, to production of powder materials with particle sizes below 0.2 mcm used in manufacturing cermet and composite materials, as well as those intended for use as fuel for thermite and pyro compositions. An aluminum wire is exploded in a gaseous chemically inert atmosphere. The aluminum powder thus produced is wetted with a solution of boric acid in ethanol with a 0,5 mole/l concentration, the powder being separated from solution in no less than an hour after wetting.
EFFECT: increase in thermal stability of aluminum powder to 580 °C.
2 tbl, 1 ex
FIELD: technological processes.
SUBSTANCE: invention pertains to plasma technology, and specifically to methods of obtaining metal powder. The method involves igniting a discharge between two electrodes, one of which is an anode, made from the spray material, with diameter of 10-40 mm. The cathode is in form of an electrolyte. The process is carried out under the following parameters: voltage between electrodes - 800 - 1600 V, discharge current - 750-1500 mA, distance between the anode and the electrolyte - 2-10 mm. According to the alternative method, the spray material is the anode, and the cathode is the electrolyte. The process takes place under the following parameters: voltage between electrodes - 500-650 V, discharge current - 1.5-3 A, distance between the cathode and electrolyte - 2-10 mm. The technical outcome is the increased efficiency of obtaining metal powder.
EFFECT: increased efficiency of obtaining metal powder.
2 cl, 8 dwg