With characteristics of vacuum furnace
Vacuum furnace is dry and sensitive, easy oxidation, or easy to break down material for design. You can use the internal part filled with inert gases, for some objects with complex components quick drying is particularly convenient.
Rectangular studio maximum effective volume. Microcomputer temperature controller can control temperature accurately.
In the viewing room steel bulletproof double glass door to make indoor objects at a glance.
What role does the vacuum induction melting furnace?
Vacuum induction melting furnace is under the condition of vacuum, using the principle of electromagnetic induction heating, vacuum melt metal smelting equipments.
The main purpose of the vacuum induction melting furnace:
Suitable for scientific research and production of nickel base and its special steel, precision alloy, high temperature alloy, rare earth metal, active metal, copper and copper alloys, hydrogen storage material, ndfeb and magnetic materials in the smelting and casting under vacuum or protective atmosphere.
The working principle of the vacuum melting furnace
(1) by melting furnace melting zone, heat preservation zone, before furnace, feeder, chimney and other major parts. Control part mainly combustion system, feeding system, the operation process of program control.
(2). The working process, the aluminum alloy ingot or foundry return < resembles ingredients or components of waste aluminum and other > in charging car capacity is about 300 kg > < every time, through the charger will be charging car aluminum alloy ingot or charge back into fusion zone in the combustion chamber, the heating melting, melting process of waste gas, smoke through the chimneys, melt after low temperature liquid aluminum from higher melting zone into position with low heat preservation zone, the liquid aluminum heat preservation in the area to reach the specified temperature and heat preservation. Open the oven door holding area operation, refining, degassing of liquid aluminum, slag treatment, the liquid aluminum purification, and keep the aluminum aluminum liquid temperature in the setting of the temperature range. Liquid aluminum after heat preservation area at the bottom of the computation in the furnace, stove out of aluminum mouth can be released before the adoption of the liquid aluminum.
Melting furnace combustion control system:
Mainly control of liquefied petroleum gas flow rate, pressure and air supply, through the control of the liquefied petroleum gas and air, and melting of liquid aluminum, temperature control.
Combustion mechanism: consists of three burner. The fusion zone 2, heat preservation zone 1, each burner were the main burner and vice burner (also called burning mouth). As long as the work burner, burning mouth is often burn, namely vice burner must always keep a fire, the main burner to burn properly, this is very critical. And the switch of the main burner is by aluminum liquid temperature, liquid level, melting temperature to decide, by a system of automatic control.
Combustion process: liquefied petroleum gas and air after Lord, vice burner and the air blower into mixed in certain proportion combustion, heating of aluminum alloy melt, flame length by proportional valve can be adjusted, achieve the goal of regulate the temperature of a liquid aluminum.
Combustion control: melting furnace control of the whole combustion process, is made up of three temperature measuring thermocouple, 2 ~ 3 liquid level sensor, a material level sensor, three flame detecting element to realize interlock control and so on ultraviolet detector.
Three temperature measuring thermocouple: installed in the furnace area (determine the aluminum temperature), heat preservation zone above the chamber of a stove or furnace (determination of furnace atmosphere temperature), emissions (determination of exhaust gas temperature).
Above the liquid level sensor, are inserted in the furnace zone, the determination of aluminum liquid level height, of which 1 level gauge probe to the furnace two ends to cover a distance of 100 mm from the former furnace, liquid aluminum reaching this level, for the liquid aluminum ceiling, another gauge probe before the end of the furnace furnace cover distance is 70 mm, on the liquid aluminum ceiling. Reach the ceiling, about 3.2 tons of liquid aluminum heat preservation area, and limited time, about 3.5 tons of liquid aluminum. Boiler no. 2, no. 3 furnace furnace furnace cover before liquid level sensor is apart from the distance of up to 170 mm, the upper limit is 140 mm, the distance is mainly based on principles of heat preservation in liquid aluminum liquid level security.
Material level sensor (photocell) located in the fusion zone tower above feeding, control burden charging the highest position.
Continuous vacuum induction melting furnace,vertical structure, assembled by the melting chamber, the cooling chamber, temperature measurement devices, feeding devices, vacuum system, control system, melting system, cooling system, operating platform and other components. Melting chamber,loading chamber and cooling chamber are all separated with a vacuum valve,which can load and put in the melting chamberwithout breaking the vacuum condition,adding alloy material, removing or ingot casting to achieve continuous operation, improving work efficiency. Meanwhile, the furnaces can cast more than one mold . Loading chamber and temperature measurement chamber are adopted the Electric horizontally structure,which can be fully automated operation. Mainly for the material like iron-based, nickel-based, cobalt-based alloys,other super alloy, high temperature alloys, magnetic materials and precision casting
Vacuum Induction Melting
Vacuum induction melting (VIM) utilizes electric currents to melt metal within a vacuum. The first prototype was developed in 1920.One of the only ways to induce a current within a conductor is through electromagnetic induction. Electromagnetic induction induces eddy currents within conductors by changing the magnetic field. Eddy currents create heating effects to melt the metal. Vacuum induction melting has been used in both the aerospace and nuclear industries.
History
E.F. Northrup built the first prototype of a vacuum induction furnace in 1920 in the United States of America. In 1923, German scientist Wilhelm Rohn continued to advance the VIM technology along with founding the Heraeus melting facility. Medium frequency furnaces were seen soon afterwards in England and Sweden in 1927.The process was initially developed to refine certain special metals such as cobalt and nickel. As these metals and alloys became more common, the process of VIM became more widely used. VIM now helps to melt a variety of metals for aircraft and nuclear applications.
Procedure
Vacuum induction melting uses currents within a vacuum to melt metal. VIM involves placing a core-less induction furnace into a vacuum chamber.The heat used to start the melting process comes from an induced current called an eddy current. The melting and casting operations are then carried out at low pressures to control the entire alloy chemistry process.
Uses
VIM was usually used for refining high purity metal and alloys. VIM is now becoming more popular due to the variety of uses now available. The commercial production of nickel titanium alloys utilizes VIM to its full extent. Other examples of using VIM include melting steels for nuclear applications, cobalt alloy for medical applications, and both high purity copper alloy and clean magnetic alloy for high permeability.The process of VIM can even begin electro-slag remelting, which can remelt electrodes.
Nickel titanium
VIM is the most widely used process for the production of nickel titanium alloys. When producing nickel titanium, the process of VIM using a hot graphite crucible sometimes causes carbon contamination which causes some of the titanium ions to form titanium carbide (TiC). These TiC particles change the transformation temperature along with the strength of the alloy. This is one drawback with the process of vacuum induction melting in graphite.
