The process of vacuum induction smelting

The process of vacuum induction smelting

Description: vacuum induction smelting is a method of smelting of eddy heating furnace in a metal conductor under vacuum condition
Vacuum induction melting is under the condition of vacuum, using electromagnetic induction heating furnace charge to produce eddy current in the metal conductor melting method, has the melting chamber volume is small, short time and vacuum smelting period, is advantageous for the temperature and pressure control, recycling volatile elements, accurate control of alloy composition, etc. As a result of above characteristic, has now for the development of special steel, precision alloy, electrothermal alloy, high temperature alloy and corrosion resistant alloy, and other special alloy production of one of the important working procedure.

The structure characteristics of the vacuum furnace

      The structure characteristics of the vacuum furnace

The structure characteristics of the vacuum furnace mainly includes:
(1) strictly vacuum seal. Metal products for sintering or heat treatment are conducted in airtight vacuum furnace, so the furnace to obtain and maintain the original air leakage rate, ensure vacuum degree of vacuum furnace, and to ensure the quality of the products have very important significance. To ensure the vacuum performance of vacuum furnace, in vacuum furnace design must follow the basic principle is: furnace should use airtight welding; Opening or less as far as possible on the furnace body is not opening; Less use or avoid use dynamic seal structure to minimize the vacuum leak; Installed on the furnace accessories, such as water-cooled electrodes, thermocouple device must be designed sealing structure is deduced.
(2) heating and insulation material can only be used in the vacuum state. Vacuum resistance furnace heating and insulation work under high temperature and vacuum, resistance to high temperature, low steam are put forward for the material, radiation effect is good, and the requirements of small coefficient of thermal conductivity, the hangzhou oxidizing request is not high. Vacuum resistance furnace is widely used tungsten, aluminum, tantalum, and heating and thermal insulation materials such as graphite, and the material under the atmospheric conditions extremely easy oxidation, generally do not use them as regular resistance furnace heating material.
(3) the cooling unit. Vacuum furnace, furnace shell, furnace cover, electric heating element guiding device (water-cooled electrodes), middle vacuum hot insulation parts are in the condition of vacuum, heating work, in order to guarantee the structure deformation of parts, vacuum sealing ring heat, not burning, not all the parts should be set according to different situations water-cooling device, in order to ensure the normal operation of the furnace and have enough life.
(4) with low voltage, high current. When the vacuum degree within the scope of 0.1 a IO0Pa, under the high voltage electric conductor can produce glow discharge phenomenon, serious can produce arc discharge that burned electric heating element, insulation, etc. As a result, the working voltage of vacuum furnace electric heating element is generally not more than 80-100 - v. At the same time, the electric heating element structure design to take some effective measures, such as to avoid a cutting-edge parts, electrode spacing cannot be too small.
(5) requires a high degree of automatic.

The principle of vacuum furnace and structure

          The principle of vacuum furnace and structure

Vacuum furnace is mainly composed of furnace, smoke tube, heating coil and a chimney. Using the negative pressure of steam heat exchange technology, the runtime will be used as heat medium of the liquid level control between the smoke and fire tube and the heating coil, the pressure in the furnace is made by high temperature exhaust gas pressure, operation and control the negative pressure condition. Full combustion of fuel burner, heating tube and the fire heat pipe is passed to the pot shell intermediate medium water, boiling water is heated by the liquid into gas phase evaporation, water vapor gradually filled with gas phase space of the furnace body, because the coil is the heating medium and the tube wall temperature is lower than the steam temperature, so that the vapor in the outside wall of the condensing coil, and the heat transfer medium to coil. After the condensation water in gravity whereabouts backwater space. Cycling heat process was realized. To take the negative pressure of heating furnace operations, mainly considering the security issue, the normal pressure will cause the high temperature furnace flue gas leakage, heat loss increase, not only will cause the destruction of the stove itself and the harm to personal safety.

Medium frequency induction furnace

Medium frequency induction furnace

Intermediate frequency furnace power supply system is one of the biggest amount of harmonic in power system harmonic source, common has the power of the medium frequency furnace and high frequency induction furnace. The six pulse intermediate frequency furnace, mainly produce 5, 7, 11, 13 second-class characteristic harmonic; For 12 pulse converter medium frequency furnace, mainly produce 11, 13, 23, 25 inferior characteristic harmonic. In general, small converter device adopts 6 pulse, relatively large adopts 12 pulse. Such as furnace transformer connect/delta Y/Y type, or to use two electric furnace transformer power supply.
For intermediate frequency furnace filter unit, we have many successful running of equipment. General design of two or more circuit, combined filtering methods for harmonic governance:
1, according to different medium frequency furnace, provide you with special filter and reactive power compensation of complete sets of equipment;
2, according to different management goal, the demand of the actual working condition, we reasonable design filter compensation scheme for you;
3, according to the actual number of intermediate frequency furnace and the load distribution, reasonable design is a single governance medium frequency furnace, or more than one centralized management;
4, according to your actual demand of industrial, we reasonable design filter compensation scheme for you, to meet the diverse needs of your industrial and mining.

The structure of the medium frequency melting furnace

The structure of the medium frequency melting furnace

Medium frequency melting furnace furnace shell structure is divided into two kinds of aluminum and steel shell structure: small capacity furnace shell generally adopt aluminum alloy material, reasonable structure small volume, convenient installation, simple maintenance, low maintenance cost. Large capacity of intermediate frequency furnace shell adopts steel structure, furnace body structure is composed of the fixed frame of blast furnace and ontology, furnace fixed frame and the furnace USES the integrity of the skeleton structure. Furnace body is rotated by a hydraulic system control, depend on either side of the furnace to achieve two hydraulic cylinder jacking, and furnace is reset by the pressure of the furnace body weight of produce.
Furnace iron liquid height and diameter is quite high. This reference foreign advanced type furnace, furnace is set on the basis of computer analysis, slim than increase, improve natural power factor, power efficiency was improved. Furnace built-in copying yoke, magnetic yoke block can reduce the magnetic flux leakage, prevent furnace heating, improve efficiency. At the same time as supporting effect, induction coil, fixed yoke furnace to achieve high strength and low noise. Yoke is to use cold rolled silicon steel sheet, stainless steel plate produced by crescent-shaped yoke, the combination of core and coil surface for circular arc surface, pressure JinChu is a surface rather than a line in the past, the structure of the compaction effect is good, less magnetic flux leakage. For the silicon steel sheet pile, instead of a cast, a splint dedicated to tighten, without special wear heart screw tightening, this structure can make full use of the permeability of silicon steel sheet area, reduce the probability of local heating.

The lead melting furnace refractory material

       The lead melting furnace refractory material

Lead melting furnace using blast furnace and electric furnace, blast furnace is currently the most widely used of lead smelting equipment.
Blast furnace of furnace body, non-working flue and furnace bottom layer typically USES clay brick masonry, furnace body with chrome brick and magnesite brick lining, tuyere zone due to the high temperature (individual parts can reach 1500 ℃ or so), together with the erosion of molten slag and lead, working conditions are harsh, general with high clay bricks, high aluminum bricks or magnesite chrome brick lining, hearth clay brick above should be laying dense chrome brick, magnesite brick, or magnesite chrome brick for working lining, can also use magnesia or magnesia chrome refractory lining ramming material dao made bottom form work.
Electric melting vacuum furnace used electrode heating, generally USES the magnesia chrome refractory ramming material rammed, non-working side wall layer and the bottom are made of magnesia refractory ramming material, side wall, lead outlet and siphon with magnesia brick masonry work layer.