What does vacuum furnace shell use commonly to cool down
The pressure in the vacuum furnace can be pumped into an industrial furnace under atmospheric pressure. The surface of the workpiece heated by vacuum furnace is unoxidized and undecarbonized. The smelting of metal with vacuum furnace is good for removing impurities. Vacuum furnace is suitable for the high quality, high purity, refractory metal melting and heating, such as tungsten, molybdenum, tantalum, niobium, titanium, heat resistant alloy steel smelting and magnetic materials, high strength steel, stainless steel, tool steel, electrical material, heat treatment of die steel etc. Vacuum furnaces appeared around the 1930s. 1927 vacuum annealing furnace for electrical materials made in America. In 1953, the vacuum self - consuming arc furnace was used to melt titanium sponge in industry. Vacuum induction furnace was widely used in industry around the 1950s. 1960 the United States developed oil quenching vacuum furnace.
The vacuum furnace is usually made up of the input power supply system and the temperature control system of the vacuum system in the closed shell of the furnace. It is made of carbon steel or stainless steel for sealing the furnace shell. In order to prevent the deformation of furnace shell after heating and the heating metamorphosis of sealing material, the furnace shell is usually cooled by water or air cooling. The furnace is located in the sealed furnace shell. According to the purpose of the furnace, there are different types of heating elements in the furnace, such as the resistive induction coil electrode and the electronic gun, etc. There is a crucible in the furnace of the vacuum furnace for smelting metal. The vacuum system consists of vacuum pump vacuum valve and vacuum meter.
In the 1950s, coreless induction furnace was developed rapidly. Later, there was the electron beam furnace, which used electron beams to shock solid fuels to strengthen surface heating and melt high-melting materials. The furnace used for forging heating was originally a hand forging furnace. Its working space was a concave groove filled with coal. The air used for burning was supplied from the lower part of the groove, and the workpieces were buried in the coal for heating. This furnace thermal efficiency is very low, the heating quality is not good, and only small workpiece heating, after development for refractory brick build by laying bricks or stones becomes close partly or fully enclosed chamber of a stove or furnace chamber furnace, can use coal, gas or oil as fuel, also can use electricity as a heat source, the artifacts in the chamber of a stove or furnace heating.
In order to facilitate the heating of large workpieces, a trolley type furnace suitable for heating ingots and large billets has appeared. After the 1920s, a variety of mechanized and automatic furnace types emerged, which could improve the productivity of the furnace and the working conditions. Industrial furnace fuel also as fuel resources development and the progress of fuel conversion technology, and by using solid fuels such as coal, coke, coal gradually convert producer gas, city gas, natural gas, gas and liquid fuels such as diesel oil, fuel oil, and developed and that meet the needs of all kinds of fuel used in combustion devices.