What factors affect the vacuum induction furnace temperature to transfer

What factors affect the vacuum induction furnace temperature to transfer

Based on the temperature field distribution equations, the internal heating type vacuum furnaces throughout the distribution of temperature field, the first depends on several aspects. The data evenly into the thermal conductivity of data of uniform density P and uniform than hot melt. Affect the vacuum furnace temperature outward transfer elements, include the following three points:
A, the strength of the furnace heating element, in the planning, first choose inner heat source. Internal heat source heating, temperature, from inside to outside. The strength of intrusive directly affect the temperature distribution in the furnace condition. By (5) type to be able to see, when the higher the heat inside roar must point the higher the temperature, temperature difference (delta T) must be together to spread area (r). So, in the process of produce practice, i.e. after manipulation of the core of appearance load furnace core power manipulation of the temperature distribution in the furnace.
Second, the response of material from the furnace core intervals (delta r), as the core power will be punctual, that is the strength of the inner heat source will be punctual, and interval of furnace core is more far the response of materials, the lower the temperature, can not reach the required temperature response. As close to the furnace core intervals, the higher the temperature, the more conducive to echo.
Third, the burden of the cooling function, burden of heat dissipation function better, internal heat to the faster loss, heat loss in the reaction of material, easily causes must point temperature drop. But if echo is expected to heat dissipation function owe good, heat is needed for convergence, allows heat to pass time longer, is advantageous to the reaction of material to absorb heat and response to, progress must point temperature. Should have under the condition of high vacuum (pa) 4 ~ 13, reaction temperature 1200 ℃ or so, core temperature will soon be able to reach the required value, thus the length of the response time depends on the reaction of material thickness, namely the interval of reaction furnace core periphery expect furnace insulation layer. Can after planning furnace scale manipulation of the power supply.

Nine items that should pay attention to maintenance of vacuum induction furnace

Nine items that should pay attention to maintenance of vacuum induction furnace

Yet how many people know that vacuum induction furnace correct maintenance method? The following is to detailed introduction:
1, after the work, needs to keep in vacuum induction furnace 133 pa vacuum.
2, there is dust or not clean inside the equipment, application of alcohol or gasoline wet silk cloth to wipe clean and dry.
3, sealing parts, parts disassembling, application of aviation gasoline or alcohol to clean, dry vacuum grease on besmear after reload.
4, equipment outside surface should often wipe, clean clean. The same is true of the use of vacuum tempering furnace.
5, electric control system of electric connection should be kept clean, fastening, in each furnace should check before fastening electric connection.
6, should check the insulation resistance of the furnace, when insulation resistance less than 1000 euro, should carefully check the electric heating element, electrode and isolation layer thermal resistance, etc., and troubleshoot rear can furnace.
7, mechanical transmission parts in accordance with the requirements of general equipment lubricating oil or oil change on a regular basis.
8, vacuum unit, valves, instruments and meters and other accessories, all press products are vacuum furnace maintenance with the specifications.
9, vacuum furnace maintenance should be a power outage maintenance, in the case of charged maintenance, must ensure that the operating personnel, maintenance personnel and equipment is absolutely safe.

The electrical principle of intermediate frequency induction furnace

The electrical principle of intermediate frequency induction furnace

In molybdenum powder before choose coal furnace and electric resistance furnace drying more boring, with the skills and the advance of science and technology, foreign molybdenum powder choose sense of intermediate frequency furnace more boring.
The electrical principle of intermediate frequency induction furnace. Will three-phase medium frequency alternating current (ac) by 6 thyristor components of three-phase bridge type all control for a dc rectifier circuit, through the flat wave reactor, into a stable dc current source, then through single phase inverter bridge, make dc current inverter can surely frequency single-phase medium frequency current, supply induction coil, intermediate frequency furnace in order to counter the reactive power of the coil, at the two ends of the coil to counter capacitance in parallel, it constitutes the LC vibration circuit.

The safe operating point of induction heating furnace

The safe operating point of induction heating furnace

1, high frequency, intermediate frequency and power frequency induction heating operation, should pay special attention to prevent to get an electric shock. Before work, the operator should wear protective equipment of the insulation, the preparation of the floor should be laid rubber pad, and pay attention to prevent leaking cooling water spilled on the floor and other places.
2, equipment internal insulation must be good, reliable grounding, equipment should be installed protective fence around, after being closed high voltage switch, no one shall be within the scope of the dangerous activities. Preparation to bright light, install exhaust equipment, keep ventilated, indoor temperature control in 18-35 ℃.
3, before starting the equipment must be cooling water, the water pressure is 1.2 ~ 2 ATM ATM (1 = 0.1 MPa). Sensors in the load artifacts, all closed the door of the cabinet.
4, according to operation procedure, comply with the provisions of the filament preheating preheating time; When heated to maintain the current bias for screen flow (Yang) value of 15% one 20%, in order to make the oscillator output efficiency is highest; Circuit of the condenser cooling water outlet temperature should be below 35 ℃, the cooling system should be less than 55 ℃, stop working after about 10 ~ 15 min to stop water supply.
5, high-frequency equipment will produce radiofrequency radiation effect, after more than a certain amount, can produce adverse effect on the human body, the radiation source of reason to the equipment such as high frequency transformer, coupling capacitor and inductor shielding measures should be taken to prevent the high frequency electromagnetic leakage. Should guarantee the working environment of the radiation intensity control within the prescribed scope (electric field intensity E 20 v/m or less, magnetic field intensity H 5 a/m or less).
6, regular replacement of capacitor in the transformer oil, the longest do not exceed half a year, and check whether "band" in good contact.
7, the use of 200 ~ 300 h after to wash the oscillation tube anode with 10% hydrochloric acid solution on the scale, until clean (but not with a knife); Then rinse with warm water, and assembly.
8, the equipment should be kept clean, dry, of the anomalous phenomenon occurred shall be immediately cut off the power supply, check and troubleshoot rear can continue to work. High frequency equipment should be the specialist is responsible for the maintenance, the maintenance should be first discharge, then maintenance, to ensure personal safety.

Aluminium scrap melting equipment - induction melting furnace

Aluminium scrap melting equipment - induction melting furnace

Common induction melting furnace, the core and has two kinds of core, the advantage of this furnace is:
(1) breathe in less and less oxidation burning loss, general metal aluminum burning only around 0.5%. Raw material broken hours is not 1%, up to 5% for aluminium scrap.
With a strong magnetic field lines (2) when the melt mixing, uniform composition, melting fast, very favorable for broken material.
(3) the unit power consumption is little, high thermal efficiency. In general, power consumption is 380 ~ 450 KWH/tons, thermal efficiency can reach 70%. Resistance furnace is corresponding to 430 ~ 600 KWH/t and 50%.
(4) covers an area of less, good operating environment
Defect is melting channel type induction furnace to replace the aluminum melting trench must be clear, when the species difficult. Followed by melting trench polluted by molten aluminum washout flake refractory in the melt.

Induction melting inject new vitality for casting production

Induction melting inject new vitality for casting production

Medium frequency induction furnace is the main equipment in the foundry, stability, reliability and security of its work is flow process of casting production line ensure normal and stable work. At present, the induction melting furnace has been developed rapidly, has gradually replaced the cupola.
Induction furnace except to smelting in the atmosphere, can also in a vacuum and argon and helium protection atmosphere such as smelting, to meet the requirements of special quality. Compared with other melting furnace, in addition to the melting principle, have the following features:
(1) using electromagnetic induction heat the material directly, high thermal efficiency.
(2) due to the melting is not used in the air, burning less elements, less impurities mixed with.
(3) the operation is simple, composition adjustment, easy to add trace elements and temperature control.
(4) around the furnace heat and less smoke generates low, improve the working environment, good for the environment protection.
(5) cover an area of an area small.
(6) current density is high, suitable for high temperature melting.
(7) easy to realize automatic control, especially can use computer to process control.
(8) frequency magnetic field of molten metal has magnetic stirring effect, beneficial ingredients evenly, and dross, uniform composition and temperature of liquid metal.
The application of the induction heating technology in China, originated in the 1950 s, the technique of inductive heating almost entirely from the former Soviet union and the Czech republic and other countries, is mainly used in machine tools, textile machinery, automobile, tractor and other manufacturing industries. Induction heating power supply amount applied to industrial production is in the 1980 s.

Vacuum induction furnace smelting ingot

        Vacuum induction furnace smelting ingot

 Die casting process, commonly used vacuum induction smelting ingot quality has very big effect on its performance. Common defects cause analysis of ingot, the author of this paper, through the experiment of different solutions, choose suitable insulation riser, add heat preservation agent, to reduce the tundish on the surface of the molten steel level, increase the speed of pouring of casting, improve casting process stirring power and so on ways to improve the quality of ingot. The results show that the aluminum silicate fiber type riser and heat preservation heat preservation agent, upper steel ingot shrinkage cavity in the region of the riser, all it is open and centralized and; As soon as possible make the surface of molten steel in tundish height to a quarter of the tundish height, cold bean skin defects and slag on the surface of the steel ingot defect will greatly reduce; Improve the stirring power in the process of casting can reduce the chemical composition segregation of steel ingot.
  Because under the condition of vacuum smelting can avoid the atmosphere produces in the process of melting and pouring easy oxidation of alloy elements, the problem such as burning, which can realize the precise control of chemical composition, it also has low gas content, low metal inclusions and low content of harmful impurity, making it the precise control of chemical composition, preparation of high purity materials. For steel material alloy content is not high, after pouring into ingot, that don't have to electroslag remelting or vacuum consumable secondary remelting, timber can be directly forged.

Medium frequency induction furnace is suitable for steel casting production

Medium frequency induction furnace is suitable for steel casting production

Steelmaking method are many, mainly include induction furnace steelmaking, open hearth steelmaking, eaf steelmaking, etc. In the cast steel workshop in general use in electric arc furnace and induction furnace. They demand for raw materials is relatively loose, the refining of molten steel quality is higher, and the characteristic of steel cycle is suitable for steel casting production, furnace, the furnace is more convenient, easy to shape, box coordinated progress of pretreatment, easy to organize production. In addition, electric furnace steelmaking equipment is simple, less investment, infrastructure and capital recovery fast.
In recent years, the series intermediate frequency furnace steelmaking development gradually. Induction medium frequency electric furnace steelmaking process is simpler, molten steel quality can be guaranteed. Many factories to pouring small castings with induction furnace steelmaking, especially revestment precision casting workshop, widely used in induction furnace for melting steel.
In heavy machinery works, still use open hearth steelmaking, open hearth furnace capacity is generally larger than the electric furnace, using open-hearth steelmaking can be a devil out of a large number of molten steel, suitable for heavy castings poured too large and complex. Open hearth steelmaking cycle is long, however, a furnace smelting steel usually need to more than six hours of time. Open hearth furnace large and complex structure, low production, steel quality is better than electric furnace, so its development is limited by a lot of. In some countries, is no longer build new open hearth furnace.
In recent decades, medium frequency induction furnace steelmaking are widely used in steel industry, the steel method is fast, high productivity, molten steel quality is guaranteed, the furnace is applicable to steel ingot production.

Medium frequency induction heating furnace for steel casting production

Medium frequency induction heating furnace for steel casting production

Steelmaking method are many, mainly include induction furnace steelmaking, open hearth steelmaking, eaf steelmaking, etc. In the cast steel workshop in general use in electric arc furnace and induction vacuum  furnace. They demand for raw materials is relatively loose, the refining of molten steel quality is higher, and the characteristic of steel cycle is suitable for steel casting production, furnace, the furnace is more convenient, easy to shape, box coordinated progress of pretreatment, easy to organize production. In addition, electric furnace steelmaking equipment is simple, less investment, infrastructure and capital recovery fast.
In recent years, the series intermediate frequency furnace steelmaking development gradually. Induction medium frequency electric furnace steelmaking process is simpler, molten steel quality can be guaranteed. Many factories to pouring small castings with induction furnace steelmaking, especially revestment precision casting workshop, widely used in induction furnace for melting steel.
In heavy machinery works, still use open hearth steelmaking, open hearth furnace capacity is generally larger than the electric furnace, using open-hearth steelmaking can be a devil out of a large number of molten steel, suitable for heavy castings poured too large and complex. Open hearth steelmaking cycle is long, however, a furnace smelting steel usually need to more than six hours of time. Open hearth furnace large and complex structure, low production, steel quality is better than electric furnace, so its development is limited by a lot of. In some countries, is no longer build new open hearth furnace.
In recent decades, medium frequency induction furnace steelmaking are widely used in steel industry, the steel method is fast, high productivity, molten steel quality is guaranteed, the furnace is applicable to steel ingot production.
As the production and the development of science and technology, dc electric arc furnace, vacuum induction furnace and equipment of the new steel refining outside the furnace method appear constantly, melting molten steel quality is greatly increased, medium frequency induction heating furnace for steel casting production reason of casting quality will be improved in the future.