Summary of five characteristics of medium frequency melting furnace

As a medium frequency heating melting equipment, the medium frequency melting furnace is mainly used in the metallurgical industry. The intermediate frequency melting furnace is analyzed from the following five aspects: composition, characteristics, working principle, specific application and advantages.

Composition

Aluminum shell structure: medium frequency power cabinet, compensation capacitor group, aluminum shell furnace body and water-cooled cable, reducer, tilting furnace operation box and so on.

Steel shell structure: medium frequency power cabinet, compensation capacitor group, steel shell furnace body, yoke and water-cooled cable, hydraulic station, tilting furnace control box, etc.

2. Features

Characteristics of medium frequency melting furnace:

(1) Medium frequency melting furnace is used for the melting of steel, stainless steel, copper, aluminum, gold, silver and other materials.

(2) Medium frequency smelting has a good electromagnetic stirring effect, which is beneficial to smelting metal temperature and uniform structure, which is beneficial to scumming and reducing impurities;

(3) The frequency range is wide, from 1KHZ to 20KHZ, the melting coil, electromagnetic stirring, heating efficiency, noise during operation, etc. can be comprehensively designed to design the induction coil and the matching compensation capacitor to determine the output frequency;

(4) Compared with thyristor intermediate frequency, energy saving is at least 20%;

(5) The equipment is small in size and light in weight. The smelting capacity ranges from a few kilograms to several hundred kilograms. It can be used in a wide range of applications. It is suitable for factory production and for small-scale melting in schools and research institutes.

3. Working principle

The working principle of the intermediate frequency melting furnace is: using a three-phase bridge type full control rectifier circuit to rectify the alternating current into direct current, after the reactor is flat wave, it becomes a constant direct current source, and then through the single-phase inverter bridge, the direct current is reversed. A single-phase intermediate frequency current that becomes a certain frequency (typically 1000 to 8000 Hz). The load consists of an induction coil and a compensation capacitor connected in a parallel resonant circuit.

Under normal circumstances, the fault of the intermediate frequency power supply can be divided into two categories according to the fault phenomenon, which cannot be started completely and cannot be operated normally after starting. As a general principle, when a fault occurs, the entire system should be thoroughly checked in the event of a power outage, which includes the following aspects:

(1) Power supply: Use a multimeter to measure whether there is power behind the main circuit switch (contactor) and the control fuse. This will eliminate the possibility of disconnection of these components.

(2) Rectifier: The rectifier adopts a three-phase fully controlled bridge rectifier circuit, which includes six fast fuses, six thyristors, six pulse transformers and one freewheeling diode. There is a red indicator on the quick fuse. When the indicator is normal, it will shrink inside the housing. When the fuse is blown, it will pop out. Some fast-melting indicators are tight. When the fuse is blown, it will get stuck inside. Therefore, for the sake of reliability, you can use the multimeter on/off to measure the fast-melting to determine if it is blown.

4. Specific application

The intermediate frequency furnace provides small transistor type medium and high frequency induction heating equipment. Its main features are: light weight, fast heating speed, high efficiency; special power saving, saving 60% compared with the load electric tube high-frequency machine; with over-current, over-voltage, over-heating and other protection functions, easy to operate, installation Convenient for a variety of applications where metal heating is required. Full name "high-frequency induction heating equipment", also known as high-frequency machine, high-frequency welding machine, high-frequency brazing machine, high-frequency heating machine, high-frequency heating machine.

1. Welding (brazing, silver welding, brazing): It mainly melts the solder by heating to a certain temperature, thereby connecting two metals of the same material or different materials.

The specific applications are as follows: 1. Welding of various hardware tools: welding of diamond tools, grinding tools, drilling tools, alloy saw blades, carbide turning tools, milling cutters, reamers, planers, woodworking drills, etc.; Welding of hardware machinery parts: hardware sanitary products, refrigeration copper fittings, lighting accessories, precision mold fittings, metal handles, egg beaters, alloy steel and steel, steel and copper, copper and copper equivalent metal or dissimilar metal silver welding, Brazing; 3. Composite bottom welding is mainly used for three-layer brazing of round, square and other shaped flat stainless steel pot bottoms and aluminum sheets, and can also be used for other metal plane brazing. 4, electric kettle (electric coffee pot) heating plate welding is mainly used for brazing between stainless steel flat bottom, aluminum sheet and various shapes of electric heating tube.

Second, medium frequency melting furnace heating (hot forging, hot matching): 1, hot forging it is mainly after the workpiece is heated to a certain temperature (different heating temperature according to the material), forging the workpiece into a punch, forged bed or other forms Other shapes. For example: case, watch embryo, handle, mold attachment, kitchen tableware, crafts, standard parts, fasteners, machining of mechanical parts, copper locks, rivets, steel brazing, hot extrusion of brazing tools, etc. 2. Thermal cooperation It mainly refers to the heating of the metal between different kinds of metals or between metal and non-metal, and the two are connected by the principle of thermal expansion or thermal melting. For example: the copper core of the computer radiator and the aluminum sheet, the buried value welding of the speaker net, the composite of the steel-plastic tube, the sealing of the aluminum foil (toothpaste skin), the rotor of the motor, the sealing of the electric heating tube and the like.

Third, heat treatment (surface quenching): It is mainly through the heating of the workpiece and other treatments to change the hardness of the metal material, the specific application is as follows: 1, a variety of hardware tools, hand tools. Such as pliers, wrenches, hammers, axes, screwdrivers, scissors (garden shears) and other quenching; 2, a variety of cars, motorcycle accessories. Such as crankshaft, connecting rod, piston pin, sprocket, aluminum wheel, valve, rocker shaft, transmission half shaft, small shaft, fork, etc.; 3, various power tools. Such as gears, shafts; 4, machine tool industry. Such as machine tool bed, machine tool guides and other quenching; 5, a variety of hardware metal parts, machined parts. Such as shaft, gear (sprocket), cam, chuck, fixture, etc. quenching; 6, metal mold industry. Such as small molds, mold accessories, mold holes, etc. quenching;

Fourth, annealing (tempering, quenching and tempering): 1, annealing of various stainless steel industries. Such as stainless steel basins, cans of annealing, annealing and annealing of the water tank, stainless steel tubes, stainless steel cutlery, stainless steel cups, etc.; 2, annealing of various other metal workpieces. Such as golf clubs, clubs, copper locks, hardware copper fittings, kitchen knives, blades, aluminum pans, aluminum drums, aluminum radiators and various aluminum products. 5. Metal melting: gold, silver, copper, iron, aluminum, etc. Metal (vacuum) smelting, powder metallurgy sintering and metal melting.

Energy saving advantage

1, heating speed, less oxidative decarburization

Since the principle of induction heating of the intermediate frequency furnace is electromagnetic induction, the heat is generated by the workpiece itself. The heating method has a fast heating rate, little oxidation, high heating efficiency, good process repeatability, and the metal surface is only slightly discolored, and slightly polished. The surface is restored to a mirrored surface to effectively achieve consistent material properties.

2, high degree of automation, can achieve automatic unmanned operation, improve labor productivity.

3, uniform heating, high temperature control accuracy

Uniform heating ensures a small temperature difference between the heated core and the workpiece. The temperature control system can accurately control the temperature to ensure product repeatability.

4. Easy replacement of induction furnace

According to the different dimensions of the machined workpiece, different sizes of induction furnace bodies need to be configured. Each furnace body is designed with a water and electricity quick-change joint, which makes the furnace body replacement simple, fast and convenient.

5, complete equipment protection

The whole machine is equipped with water temperature, water pressure, phase loss, overpressure, overcurrent, voltage limiting/current limiting, starting overcurrent, constant current and buffer starting, which makes the equipment start smoothly, reliable and rapid protection, and stable operation.

6, low energy consumption, no pollution

The heating efficiency is high, compared with other heating methods, the energy consumption is effectively reduced, the labor productivity is high, the pollution is non-polluting, and the equipment meets the environmental protection requirements.