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ISO9001 Approved Manufacturer of metal coupling

The electric furnace is a heating furnace that converts the electric energy in the furnace into heat to heat the workpiece. Compared with the fuel furnace, the advantages of the electric furnace are: the atmosphere in the furnace is easy to control, and it can even be evacuated; the material is heated quickly, the heating temperature is high, and the temperature is easy to control. .ISO9001 Approved Manufacturer of metal coupling

advantage

  The electric furnace is a heating furnace that converts the electric energy in the furnace into heat to heat the workpiece. Compared with the fuel furnace, the advantages of the electric furnace are: the atmosphere in the furnace is easy to control, and it can even be evacuated; the material is heated quickly, the heating temperature is high, and the temperature is easy to control. ; The production process is easier to realize mechanization and automation; the labor hygiene conditions are good; the thermal efficiency is high; the product quality is good; and the more environmentally friendly is a good product for the increasingly serious environmental problems. Electric furnaces in the metallurgical industry are mainly used for smelting, heating and heat treatment of steel, ferroalloys, non-ferrous metals, etc. Industrial-scale electric furnaces appeared at the end of the 19th century. Since the 1950s, due to the increase in demand for advanced metallurgical products and the decline in electricity costs with the development of the power industry, the proportion of electric furnaces in metallurgical furnace equipment has increased year by year. Electric furnaces can be divided into resistance furnaces, induction furnaces, electric arc furnaces, plasma furnaces, electron beam furnaces, etc. ISO9001 Approved Manufacturer of metal coupling

Type introduction
resistance furnace

  An electric furnace that uses the Joule heat generated by passing an electric current through a conductor as its heat source. According to the way of electric heat generation, resistance furnaces are divided into two types: direct heating and indirect heating. In the direct heating resistance furnace, the current directly passes through the material. Because the electric heating power is concentrated in the material itself, the material heats up very quickly, which is suitable for processes requiring rapid heating, such as the heating of forging blanks. This kind of resistance furnace can heat the material to a very high temperature, such as a carbon material graphitization electric furnace, which can heat the material to more than 2500 ℃. The direct heating resistance furnace can be made into a vacuum resistance heating furnace or a protective gas resistance heating furnace. In powder metallurgy, it is often used for sintering tungsten, tantalum, niobium and other products. When using this furnace heating should pay attention to:

① In order to heat the material evenly, the conductive cross-section and conductivity of each part of the material are required to be consistent;

② Since the resistance of the material itself is quite small, in order to achieve the required electric heating power, the working current is quite large, so the contact between the power transmission electrode and the material should be good to avoid arcing and burn the material, and the resistance of the power transmission bus should be small to reduce circuit loss. ; Most of the resistance furnaces are indirect heating resistance furnaces, which are equipped with a resistance body specially used to realize the electric-thermal conversion, called an electric heating body, which transfers heat energy to the materials in the furnace. ISO9001 Approved Manufacturer of metal coupling

The shell of this electric furnace is made of steel plate, the furnace is lined with refractory materials such as ceramic fibers, and materials are placed inside.

 The most commonly used heating elements are iron-chromium-aluminum heating elements, nickel-chromium heating elements, silicon carbide rods and molybdenum disilicide rods, silicon carbide rods, and zirconium diboride ceramic composite heating elements. According to needs, the furnace atmosphere can be ordinary atmosphere, protective atmosphere or vacuum. The general power supply voltage is 220 volts or 380 volts, and an intermediate transformer that can adjust the voltage is configured if necessary. Single-phase power supply for small furnaces (<10kW) and three-phase power supply for large furnaces. For materials with a single variety and a large batch of materials, a continuous furnace should be used for heating. For resistance furnaces whose furnace temperature is lower than 700℃, most of them are equipped with blowers to strengthen the heat transfer in the furnace and ensure uniform heating. The resistance furnace for melting fusible metals (lead, lead-bismuth alloy, aluminum and magnesium and their alloys, etc.) can be made into a crucible furnace; or a reverberatory furnace with a molten pool, and an electric heating body is installed on the top of the furnace. Electroslag furnace is a resistance furnace that realizes electrothermal transformation by molten slag (see electroslag remelting).

Induction furnace

  Introduction of induction furnace An electric furnace that uses the induction electrothermal effect of materials to heat or melt materials. The basic component of an induction furnace is an induction coil wound with a copper tube. AC voltage is applied to both ends of the induction coil to generate an alternating electromagnetic field. The conductive material is placed in the induction coil, and eddy current is generated in the material due to electromagnetic induction, and the electrical energy is converted into heat energy to heat the material by the action of resistance; therefore, it can also be considered that Induction electric heating is a direct heating resistance electric heating. ISO9001 Approved Manufacturer of metal coupling

  The characteristic of induction electric heating is that the electric heating power (current distribution) transformed in the heated material is very uneven, the surface is the largest and the center is the smallest, which is called the skin effect. In order to improve the electrothermal efficiency of induction heating, the power supply frequency should be appropriate. High-frequency electricity is used for small melting furnaces or surface heating of materials, and medium-frequency or power frequency electricity is used for large melting furnaces or deep penetration heating of materials. The induction coil is a load with considerable inductance, and its power factor is generally low. In order to improve the power factor, the induction coil is generally connected in parallel with intermediate frequency or high frequency capacitors, which are called resonant capacitors. The gap between the induction coil and the material should be small. The induction coil should be made of a square copper tube. The tube is cooled by water. The gap between the turns of the induction coil should be as small as possible, and the insulation should be better. Induction heating device is mainly used for heating and casting of steel, copper, aluminum and zinc, etc. It has fast heating, less burning loss, high degree of mechanization and automation, and is suitable for automatic operation.

Induction furnace series heating furnace features:

(1) The heating speed is fast, the production efficiency is high, the oxidation decarbonization is less, and the cost of materials and forging dies is saved.

Since the principle of intermediate frequency induction heating is electromagnetic induction, its heat is generated in the workpiece itself. Ordinary workers can carry out the continuous work of the forging task ten minutes after going to work with the intermediate frequency electric furnace, and there is no need for professional workers to burn the furnace and seal the furnace in advance. . There is no need to worry about the waste of heated billets due to power outages or equipment failures. Due to the fast heating rate of this heating method, there is very little oxidation. Compared with coal-fired furnaces, each ton of forgings saves at least 20-50 kilograms of steel raw materials, and its material utilization rate can reach 95%. Because the heating method heats evenly and the temperature difference between the core surface is extremely small, the life of the forging die is greatly increased in forging, and the surface roughness of the forging is also less than 50um. ISO9001 Approved Manufacturer of metal coupling

(2) The working environment is superior, the working environment of workers and the image of the company are improved, no pollution, and low energy consumption.

Compared with the coal furnace, the induction heating furnace will no longer be roasted and smoked by the coal furnace under the scorching sun, and can meet the requirements of various indicators of the environmental protection department, and at the same time establish the company's external image and the future development trend of the forging industry . Induction heating is the most energy-saving heating method in the electric heating furnace. The power consumption of a ton of forgings heated from room temperature to 1100 ℃ is less than 360 degrees.

(3) The heating is uniform, the temperature difference between the core and the surface is extremely small, and the temperature control accuracy is high.

Induction heating furnace has the advantages of small size, light weight, high efficiency, excellent thermal processing quality and favorable environment. It is rapidly eliminating coal-fired furnaces, gas furnaces, oil furnaces and ordinary resistance furnaces. ISO9001 Approved Manufacturer of metal coupling

  Induction melting furnaces used in industry include crucible furnaces (coreless induction furnaces) and furnace furnaces (cored induction furnaces). Crucibles are made of refractory materials or steel, with capacities ranging from a few kilograms to dozens of tons. The smelting feature is that the melt in the crucible is subjected to electric power, forcing the liquid level of the molten pool to bulge, and the melt flows from the center of the liquid surface to the surroundings, causing a circulating flow. This phenomenon is called electrokinetic effect, which can make the melt composition uniform. The disadvantage is that the slag tends to the periphery and the coverage is poor. Compared with the melting trench furnace, the crucible furnace is flexible in operation, high in melting temperature, but low in power factor and high in power consumption. The inductor of the melting trench furnace is composed of iron core, induction coil and melting trench furnace lining. The melting trench is one or two band-shaped annular trenches, which are filled with melt connected to the melting pool. In principle, the ditch furnace can be regarded as an iron core transformer with only one turn of secondary coil and short circuit. The induced current flows in the melt in the trough to realize the electrothermal transformation. ISO9001 Approved Manufacturer of metal coupling

In production, after each furnace of metal is smelted, the molten pool cannot be emptied, otherwise it is easy to dry up, and a part of the melt must be reserved as the starting melt of the next furnace. The temperature of the melting ditch is higher than that of the molten pool, and it is subject to the erosion of the melt flow, so the furnace lining of the melting ditch is easily damaged. In order to facilitate maintenance, the inductors of modern furnaces are made into assemblies that are easy to replace. The capacity of the furnace furnace ranges from several hundred kilograms to more than one hundred tons. The ditch furnace supplies power frequency power. Since the iron core made of silicon steel sheet is used as the magnetic path, the electrical efficiency and power factor are very high. Furnace furnace is mainly used for the melting of cast iron, copper, zinc, brass, etc. It can also be used as a mixed melting furnace to store and heat the melt.

Electric arc furnace

 Electric furnaces that smelt metals and other materials using the thermal effect of an electric arc. According to the heating method, it is divided into three types: ① indirect heating electric arc furnace. The arc is generated between the two electrodes, without contacting the material, and heating the material by thermal radiation. This kind of furnace is noisy and low in efficiency, and is gradually being phased out. ② Direct heating of the electric arc furnace. The electric arc is generated between the electrode and the material, which directly heats the material; the three-phase electric arc furnace for steelmaking is the most commonly used direct heating electric arc furnace (see EAF steelmaking). ③Submerged arc furnace, also known as reduction furnace or submerged arc furnace. One end of the electrode is buried in the material layer, an arc is formed in the material layer, and the material is heated by the resistance heating of the material layer itself; it is often used for smelting ferroalloys (see ferroalloy electric furnace) ISO9001 Approved Manufacturer of metal coupling

Vacuum arc furnace

  It is an electric furnace that directly heats and smelts metal with an electric arc in a evacuated furnace body. The gas in the furnace is thin, and the arc is mainly generated by the vapor of the molten metal. In order to stabilize the arc, direct current is generally supplied. According to the melting characteristics, it is divided into metal remelting furnace and casting furnace. According to whether the electrode is consumed (melted) during the smelting process, it is divided into consumable furnace and non-consumable furnace. Most of the industrial applications are consumable furnaces. Vacuum arc furnaces are used for the melting of special steels, reactive and refractory metals such as titanium, molybdenum, and niobium (see vacuum metallurgy).


  Arc heating can be considered as arc resistance heating. Arc (arc resistance) stability is a necessary condition for the normal production of the furnace. AC electric arc furnaces usually use power frequency power. In order to stabilize the arc, the furnace power supply circuit must have appropriate inductive reactance, but the existence of inductive reactance will reduce the power factor and electrical efficiency. Reducing the current frequency is the way to develop the AC electric arc furnace. The resistance value of the arc resistance is quite small. In order to obtain the necessary heat, the furnace needs a considerable working current. Therefore, the resistance of the short network of the furnace should be as small as possible to avoid excessive circuit loss. For a three-phase electric arc furnace, the impedance of the three phases should be close to the same, so as to avoid unbalanced three-phase loads.

Plasma furnace

An electric furnace that heats or smelts using plasma generated when working gas is ionized. Plasma-generating devices, usually called plasma guns, include arc plasma guns and high-frequency induction plasma guns. The working gas is passed into the plasma gun, and the gun has a device to generate an arc or a high-frequency (5-20 MHz) electric field. The working gas is ionized after being acted on to generate a plasma composed of electrons, positive ions, and a mixture of gas atoms and molecules. . After the plasma is ejected from the nozzle of the plasma gun, a high-speed and high-temperature plasma arc flame is formed, and the temperature is much higher than that of the ordinary arc. The most commonly used working gas is argon, which is a monatomic gas, easily ionized, and an inert gas that protects the material. The working temperature can be as high as 20000□; it is used for smelting special steel, titanium and titanium alloys, superconducting materials, etc. Furnace types include water-cooled copper crystallizer furnaces, hollow cathode furnaces, plasma furnaces equipped with induction heating, and plasma furnaces with refractory linings (see plasma metallurgy). ISO9001 Approved Manufacturer of metal coupling

Electron beam furnace

 An electric furnace in which the material is heated and melted by bombarding it with high-speed electrons. In the vacuum furnace shell, the cathode is heated by a low-voltage electric filament to emit electrons. The electron beam is accelerated by the high-voltage electric field that accelerates the anode, and bombards the metal material located at the anode to convert the electrical energy into heat energy. Because the electron beam can be highly concentrated by the electromagnetic focusing device, high temperature can be generated in the part where the material is bombarded. Electron beam furnaces are used to smelt special steels, refractory and reactive metals.

Electric furnaces used in industry are classified into two categories: periodic operation furnaces and continuous operation furnaces.

 Periodic operation furnaces are divided into: box furnaces, sealed box furnaces, pit furnaces, bell furnaces, trolley furnaces, and dumping drum furnaces.

 Continuous operation furnaces are divided into: kiln car furnaces, push rod furnaces, roller hearth furnaces, vibrating hearth furnaces, rotary hearth furnaces, walking furnaces, traction furnaces, continuous drum furnaces, conveyor belt furnaces, etc. Among them, conveyor belt furnaces can be divided into: mesh belt furnaces, stamping chain plate furnaces, casting chain plate furnaces, etc... ISO9001 Approved Manufacturer of metal coupling

Electric furnace

The electric heating furnace can use metal heating element or non-metal heating element to generate heat source. Its simple structure and wide application are its main features. It can be widely used in annealing, normalization, quenching, tempering, carburizing and carbonitriding. Wait. The main metal heating elements include Ni-Cr heating wire (the most common, up to 1200 ℃), Mo-Si alloy and pure metals such as W, Mo; non-metal heating elements include SiC (the most common, the highest can be heated to 1600 ℃) ), LaCrO3 and graphite rod (can be heated to 2000℃ in vacuum or protective atmosphere).

advantage:

1) It is easy to get high temperature compared with the fuel furnace.

2) It can be heated from the inside of the material.

3) Easy to use in controlled atmosphere furnace and vacuum furnace.

4) The electric furnace has no heat loss from the exhaust gas of the fuel furnace, so the thermal efficiency is high.

5) It is easy to control the temperature, which is convenient for remote control and fine adjustment.

6) Fast heating is possible.

7) Good operation performance, no pollution to the environment. ISO9001 Approved Manufacturer of metal coupling
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shortcoming:

1) Need to increase the cost of power distribution equipment.

2) High cost of electricity.

3) When the resistance heating temperature exceeds 1000 ℃, the refractory material may conduct electricity, and it is necessary to pay attention to the insulation problem.

· develop ·
In 2010, China’s manufacturing industry accounted for 19.8% of global manufacturing output, slightly higher than the 19.4% of the United States, ranking first in the world. The rapid development of China’s manufacturing industry has driven the development of China’s oven, furnace and electric furnace manufacturing industries. According to the statistics of the National Bureau of Statistics, in 2010, the number of enterprises above designated size in the oven, furnace and electric furnace manufacturing industry increased to 308, with a total industrial output value of 16.288 billion yuan, a year-on-year increase of 30.79%; sales revenue was 16.387 billion yuan, a year-on-year increase of 32.63% ; The total profit was 1.043 billion yuan, a year-on-year increase of 79.17%.

 70%-80% of the parts and components in the automobile and tractor industries need heat treatment, while 100% of tools, cutting tools and bearing products need heat treatment. The service life of some civilian light industrial metal products is also improved by heat treatment. At the same time, the fastener industry, bearing industry, chain industry, tool industry, automobile, tractor, and motorcycle parts industry all rely on the improvement of heat treatment quality to enhance their competitiveness. 400,000-500,000 tons of thermal processing capacity will be added. In addition, most of the domestic ovens, furnaces and electric furnaces are outdated and outdated and will tend to be eliminated and updated. my country's demand for thermal processing equipment is very strong. The development prospect of electric furnace is promising. ISO9001 Approved Manufacturer of metal coupling

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