The working principle of the vacuum melting furnace

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

 
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

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.

Vacuum single crystal directional solidification furnace

                             Vacuum single crystal directional solidification furnace

Vacuum single crystal/directional solidification furnace is using the medium frequency induction heating to melt metals or alloys , specially designed holding furnace and cooling system are formed thermal gradient, By modern equipment directionally solidified and single crystal parts of the pull-down mechanism to get maximum temperature gradient and the formation of the solidification interface, it adopts a a structure specifically designed to meet the requirements of the temperature gradient.Application field:production of high-temperature aerospace materials.

Vacuum Induction Melting

       

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.

Thermocouple select for vacuum furnace

   Thermocouple select for vacuum furnace

Thermocouple temperature measurement at a specific vacuum: inexpensive metals, precious metals and refractory metal thermocouple characteristics, selection and application of tungsten-rhenium thermocouples detailed discussion of industrial classification, vacuum furnace for thermocouple configuration and installation, vacuum Profile factors furnace temperature accuracy, imports thermocouple localization studies, results showed: Domestic vacuum furnace for thermocouple can replace expensive imported thermocouple.

Vacuum Furnaces for Heat Treating, Brazing and Sintering Introduction

 Vacuum Furnaces for Heat Treating, Brazing and Sintering Introduction

 processing temperatures that are more efficiently accomplished by electric vacuum furnaces.  Further-more, the food and medical instrument industries have become attracted to the“bright” non-oxidized  finish
on parts heat treated by vacuum furnaces, which eliminates a cleaning  step. There are a wide  variety of electric and fuel-fired furnace types  used for materials processing. Each furnace type has advantages and disadvantages depending on the process  being conducted. Selection
of the furnace type  depends on the type and volume of  material being processed,the process economics, and the user’spreferences. One  furnace type gaining increased usage is  the electric vacuum furnace (Figure 1).  The connected electric load for this type of  furnace is typically
in the range of 40 kW  to 300 kW.
Applications
 Electric vacuum furnaces  can provide this level of quality. Also, the automotive industry’s switch to  lighter, stronger materials has created  a need for higher Process Fundamentals
Applications for these  high-temperature electrically  heated
vacuum furnaces include:
Electrically heated vacuum furnace technology has  eliminated environmental problems associated with  salt bath furnaces. Electric  vacuum furnaces also provide more precise control than traditional gas-fired furnace  technology.In addition, more demanding  quality requirements for  high temperature processing, such as  that imposed by the aerospace industry,  have pressured the heat treat industry  for continuously improved reliability and  repeatability.