Plasma is characterized as an electrically neutral medium of unbound positive and negative particles, with an overall charge of roughly zero. Like a gas, plasma has no defined shape unless enclosed in a container. To generate plasma, we apply an electrical field to a gas, with the goal of removing electrons from their orbit around the nuclei. This creates a mix of ions and free-flowing electrons, which give the plasma key properties, including its electrical conductivity, a magnetic field, and sensitivity to external electromagnetic fields.
A key requirement for producing and sustaining plasma, is continued energy input. Induction is an ideal means of providing that continuous energy input for plasma generation. Some typical industrial applications for plasma include:
Surface treatments (plasma spray coating)
Etching in micro-electronics
To generate plasma, we apply an electrical field to a gas, with the goal of removing electrons from their orbit around the nuclei. These free-flowing electrons give the plasma key properties, including its electrical conductivity, a magnetic field, and sensitivity to external electromagnetic induction heating fields.
Renowned across the gas and pipeline processing industries, HLQ MYD series Pipeline and Tube Coating Systems are globally acknowledged for their ability to provide the highest levels of quality and performance in pipe coating, heat treatment and preparation applications. HLQ MYD series offshore systems revolve around field joint processing, with a series of induction systems utilized for heating and coating of field joints on pipe laying vessels.
HLQ MYD series Pipeline Coating Renowned across the gas and pipe processing industries, HLQ MYD series Pipe and Tube Coating Systems are globally acknowledged for their ability to provide the highest levels of quality and performance in pipe coating, heat treatment and preparation applications. HLQ MYD series offshore systems revolve around field joint processing, with a series of induction systems utilized for heating and coating of field joints on pipe laying vessels.
Modern technology has placed increased emphasis on coatings’ corrosion protection, electrical characteristics, thermal properties, appearance, and other special properties. Such coatings have included simple lacquers and paints, plastics, ceramics, metals, and various chemical conversion coatings. Induction heating has found increased application for coatings which must be ‘cured’ or ‘dried’ rapidly. Induction is suitable for either drying pipe after alkaline cleaning and rinsing, or for curing coating applied to the surface.
Induction heating is particularly applicable to high-speed continuous coating lines. Since heating occurs directly in the pipe as it passes through an induction coil, it is heated almost instantaneously to a controlled temperature. This allows a short heating zone for processing, saving space and preventing problems associated with a shutdown in the processing line, such as excess heating of the wire coating from residual heat. Integration of an induction heating operation with a production line is simple because of instantaneous heat control and ease of transporting the wire though the short induction coil.
Induction Heating is used to cure organic coating such as paint on metallic substrates by generating heat with in the subtract .By this mean curing occurs from within minimizing the tendency for formation of coating defects . A typical is application is drying of paint on sheet metal. Induction heating of metal parts to adhesive induction curing temperatures is utilized in a many automotive processes, such as the use of thermosetting adhesives to produce clutch plates, brake shoes and auto bumper components. Shafts are typically bonded to the squirrel cage rotors in the manufacture of small motors. In copying machines, plastic components are adhesively bonded to aluminum rotors; a thermoplastic glue is used to hold foam rollers on metal shafts. Once the rollers wear out, the shaft is heated and the foam replaced. Modern induction heating can solve many of these problems. Heating with induction provides reliable, repeatable, non-contact and energy-efficient heat in a minimal amount of time, so that the curing process can be completed with minimal energy and time. Improved temperature ramping cycles can be achieved with computer control of the solid state power supply. To eliminate extra steps for loading and unloading ovens, induction heat stations can be incorporated into a production line. Finally, induction heating can be performed in extremely clean environments, vacuum conditions or special atmospheres, allowing for unique curing solutions.
Although induction heating is normally used with metals or other conductive materials, plastics and other non-conductive materials can often be heated very effectively by using a conductive metal susceptor to transfer the heat. Typical RF power supplies for induction curing applications range from 4 to 60kW, depending on the parts and application requirements.
In order to want to improve safety and productivity, and reduce energy costs, by using induction instead of resistive heating. To maximize productivity, they want to be able to heat 3 brass rods at a time to 780° C within 25 seconds. For this application test, we are only heating one rod, so our goal is to heat the single rod to 780° C within 25 seconds with less than 45 kW of power. This will ensure that when heating 3 rods, that the 110 kW system will meet the production requirements.
Equipment DW-HF-70kW Induction Heating Power Supply, operating between 10-50 kHz
Materials • Brass rod • Custom coil, 10 turns, D=50mm, designed and manufactured by DaWei Induction Power Technologies for this specific application – capable to heat 3 rods at a heat cycle.
Key Parameters Temperature: 780° C Power: 70 kW Voltage: 380 – 480 V Time: 24 sec Frequency: 32 kHz
The DW-HF series Power Supply was connected to the DW-HF-70kw Heat Station.
The custom Coil was attached to the Heat Station.
The Brass rods were placed inside the Coil.
The Power Supply was turned on.
The DW-HF series operating at 20 kW was able to successfully heat the single brass rod within 24 seconds, which was less than the 25 second time requirement established for the test. Three brass rods are expected then to heat within 25 seconds with approximately 60 kW of power (3 rods will be 3x the load and 3x the power). The 90 kW Induction system will therefore meet the customer’s requirements.
A source of high frequency electricity is used to drive a large alternating current through a induction coil. This induction heating coil is known as the work coil. See the picture opposite. The passage of current through this induction heating coil generates a very intense and rapidly changing magnetic field in the space within the work coil. The workpiece to be heated is placed within this intense alternating magnetic field. Depending on the nature of the workpiece material, a number of things happen… The alternating magnetic field induces a current flow in the conductive workpiece. The arrangement of the work coil and the workpiece can be thought of as an electrical transformer. The work coil is like the primary where electrical energy is fed in, and the workpiece is like a single turn secondary that is short-circuited. This causes tremendous currents to flow through the workpiece. These are known as eddy currents. In addition to this, the high frequency used in Induction Heating applications gives rise to a phenomenon called skin effect. This skin effect forces the alternating current to flow in a thin layer towards the surface of the workpiece. The skin effect increases the effective resistance of the metal to the passage of the large current. Therefore it greatly increases the induction heating effect of the induction heater caused by the current induced in the workpiece.
Magnetic Induction Heater is a process equipment which is used to melt,braze,forge,bond,heat treating,harden or soften metals or other conductive materials. For many modern manufacturing processes, Magnetic induction heating equipment offers an attractive combination of speed, consistency and control.The basic principles of magnetic induction heating have been understood and applied to manufacturing since the 1920s. During World War II, the technology developed rapidly to meet urgent wartime requirements for a fast, reliable process to harden metal engine parts. More recently, the focus on lean manufacturing techniques and emphasis on improved quality control have led to a rediscovery of induction technology, along with the development of precisely controlled, all solid state induction power supplies.
Magnetic Induction Heaterrelies on the unique characteristics of induction heating radio frequency (RF) energy – that portion of the electromagnetic spectrum below infrared and microwave energy. Since heat is transferred to the product via electromagnetic waves, the part never comes into direct contact with any flame, the inductor itself does not get hot, and there is no product contamination. When properly set up, the process becomes very repeatable and controllable.
1.IGBT module and soft switiching inverting technologies are as in the production of the generator,higher reliability can be do.
2. Small and portable ,compared with SCR controlled machine only 1/10 working space is needed. 3. High efficiency to save energy,high efficiency and power far can be maintained
4. The generator is adatable in a large frequency range from 1KHZ to 1100KHZ,installation can be done very easily according to our manual.
5. 100%duty cycle ,continuous working ability at maximum power.
6. Constant power or constant voltage control mode.
7. Display of output power,output frequency,and output voltage.
1. IGBT module and inverting technologies of the first generation been used.
2. Simple structure and light weight and easy for maintenance.
3. Simple to operat ,afew minutes is enough to learn it.
4. Simple to install,installation can be done by unprofessional person very easily.
5. advantages of the model with timer,the power and the operatingtime of the heating period and the rain period can be preset repectively,to realize a simple heating curve,this model is suggested to use for batch production to improve the repeatability.
6. The separated models are designed to fit the dirty surrounding of some cases.
Induction Brazing Basics for jointing copper,silver,brazing,steel and stainless steel,etc.
Induction Brazing uses heat and filler metal to join metals. Once melted, the filler flows between close-fitting base metals (the pieces being joined) by capillary action. The molten filler interacts with a thin layer of the base metal to form a strong, leak-proof joint. Different heat sources can be used for brazing: induction and resistance heaters, ovens, furnaces, torches, etc. There are three common brazing methods: capillary, notch and moulding. Induction brazing is concerned solely with the first of these. Having the correct gap between the base metals is crucial. A too-large gap can minimize the capillary force and lead to weak joints and porosity. Thermal expansion means gaps have to be calculated for metals at brazing, not room, temperatures. Optimum spacing is typically 0.05 mm – 0.1 mm. Before you braze Brazing is hassle-free. But some questions should be investigated — and answered — in order to assure successful, cost-effective joining. For instance: How suitable are the base metals for brazing; what’s the best coil design for specific time and quality demands; should the brazing be manual or automatic?
At DAWEI Induction we answer these and other key points before suggesting a brazing solution. Focus on flux Base metals must usually be coated with a solvent known as flux before they are brazed. Flux cleans the base metals, prevents new oxidation, and wets the brazing area prior to brazing. It is crucial to apply sufficient flux; too little and the flux may become saturated with oxides and lose its ability to protect the base metals. Flux is not always needed. Phosphorous-bearing filler can be used to braze copper alloys, brass and bronze. Flux-free brazing is also possible with active atmospheres and vacuums, but the brazing must then be performed in a controlled atmosphere chamber. Flux must normally be removed from the part once the metal filler has solidified. Different removal methods are used, the most common being water quenching, pickling and wire brushing.