The advantage of main equipment components in COOLDO INDUSTRIAL
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1、Medium frequency power supply

（1）、Principle of work

Through the three-phase AC power supply through the three-phase bridge rectifier, become adjustable DC power supply, through the reactance filter, filter after losing to the single phase inverter bridge, Through the pulse control, make single bridge diagonal alternation switch become single-phase 1000hz intermediate frequency current. Resonance circuit is made by induction coil and compensation capacitor composition, and the current to the induction coil .The sensors in metal charge generating vortex, then heated to melting furnace

（2）、Main components—silicon-controlled rectifier ：

The silicon controlled my company used is main procurement in Hubei TECH Semiconductors Co., Ltd. (TECHSEM)、Hangzhou Hanan Semiconductors Co., Ltd and Zhejiang Sifang Semiconductors Co., Ltd, the three companies above are China silicon manufacturing industry leader, the production of the silicon controlled quality and stability, have a strong ability of anti impact current，not easy to damage, 20%~30% higher price than the same industry.

（3）、Main components—the main control circuit board：

Parallel SCR intermediate frequency power supply used in circuit board, it is my company independent research and production, research and development engineers timely update and improvement of circuit board  that guarantee the company in the industry leading level; production welding circuit board all through my company profession quality inspection personnel test and check one by one, to eliminate substandard products sold out and ensure that the equipment safety.

（4）、Main components—circuit breaker：

My company uses the circuit breaker in the procurement of Shanghai people Electric Appliance Switch Factory. This company was founded in the nineteen seventies, it is the production and sales of high and low voltage electrical appliances, instruments and meters, complete set of power transmission and distribution equipment, high voltage electrical components, building electrical appliances, wire and cable products research and development, production, sales and services for the integration of a manufacturing enterprise. This enterprise won the "Chinese enterprise image AAA level enterprise", "Chinese famous quality products", "China hundred outstanding enterprise" and so on the title. 

         

2、Capacitor device：

（1）、Principle of work 

 Capacitor cabinet and the induction coil connected in parallel to compensate for the induction coil of the inductive reactive power, at the same time with the coil to form a resonant circuit to achieve proper frequency and equivalent impedance. After compensation, intermediate frequency power supply need only provide required load active power and a small amount of reactive power, intermediate frequency power supply capacity can greatly reduced.

High power induction furnace needs a large amount of compensation capacitor, in order to reduce the occupied space and electromagnetic leakage. My company's capacitor cabinet adopts a unique double installation mode. Large current water bus use special mold custom, water cooling chamber and a molded copper, No welding, therefore no oxidation, water cooling and the conductive efficiency is high.

（2）、Main components—electric capacitor

    Capacitor cabinet used to compensate the reactive power of induction coil, At the same time with the coil to form a resonant circuit, to achieve proper frequency and equivalent impedance. After compensation, intermediate frequency power supply only need to provide the required load active power and a small amount of reactive power. Intermediate frequency power supply capacity can be greatly reduced. The electric capacitor my company used is main procurement in Xin'An River Power Capacitor Limited and Hangzhou keang  power & electrical apparatus Co., Ltd. These two companies are famous for domestic electric capacitor production enterprises, registered capital of over RMB20000000. Because of its first-class quality, overvoltage capability, win the user's consistent high praise in the long-term process of applications

  

3、Coreless induction furnace aluminum furnace

（1）Principle of work

Intermediate frequency electric furnace complete sets of equipment is change the frequency of 50HZ alternating current into intermediate frequency（more than 250HZ to 2500HZ），the three-phase alternating current into direct current, after the rectification, the DC power into the adjustable frequency current, Supply consists of a capacitor and an induction coil in the intermediate frequency alternating current flowing, to produce a high density of lines of force in the induction coil, and cut the metal materials filled in the induction coil, in metal materials they will have a great eddy current. It based on the principle of electromagnetic induction heating metal. Use of intermediate frequency power supply establishment of intermediate frequency magnetic field, the ferromagnetic material generated internally induced eddy current and heat to achieve the heating material for the purpose. Intermediate frequency electric furnace uses 250-2500Hz medium frequency power supply for induction heating and melting heat. Intermediate frequency electric furnace for smelting steel, alloy steel, special steel, can also be used for copper, aluminum and other non-ferrous metal smelting and extraction temperature. Equipment has the advantages of small volume, light weight, high efficiency, less power consumption, melt fast temperature rising, the furnace temperature is easy to control, high production efficiency.

My company produces aluminum shell furnace use thickening type high purity aluminum panel, can be used for a long time without deformation, stable.

（2）Main components—induction coil

Induction coil used in type T2 (99.9% purity electrolytic copper), wall thickness ≥ 4.5mm extrusion of rectangular tube in the special die winded, It ensures the coil of the rigid, and also has the most conductive section. According to the ISO431-1981 standards for selection of coil material, reach minimum copper loss and high electromagnetic conversion rate.

Induction coil made of high temperature resistance, high pressure resistance insulating paint, insulation grade reaches H grade. Induction coil before they leave the factory will after 12kg/cm2（Schematic diagram for the water pipe and the induction coil connected）hydraulic pressure test 36 hours and 7000v withstand voltage test, there is absolutely no water leakage phenomenon 

Classification of induction furnace

According to the power frequency, electric induction furnaces can be divided into three categories: high frequency furnace, medium frequency furnace and power frequency furnace; 

According to the Requirement of application, it can be divided into melting furnace, heating furnace, heat treatment equipment and welding equipment; 

According to the structure form, transmission methods and so on, it also can be classified. Generally, electric induction furnace be divided into several types: cored induction furnace, coreless induction melting furnace, vacuum induction melting furnace, induction hardening furnace and induction heat equipment, etc.

Following we will introduce cored and cordless induction furnace 
   

Cored induction furnace
Cored induction furnace is known as iron core through induction coil, and the heat source is a round metal groove, so it is called a groove type furnace. Additionally cored induction furnace can be divided into two kinds: the slot type and the closed slot type. Basically, the slot type has been eliminated, the closed slot type is in the majority now.  Cored induction furnace is mainly used for copper, aluminum, zinc , other non-ferrous metals smelt and heat preservation, as well as it can preserve heat for the cast iron, etc. This type of furnace have a series of advantages, such as fast heating, high electricity and thermal efficiency, high power factor, less metal loss, smelting low cost, less equipment investment(1/2~1/3) of the coreless induction melting furnace), convenient operation, etc. However, there should be a melt in the furnace when machine start working, it is difficult to play the furnace and change the metal, so, it only applies to smelting and preserving heat for a single varieties and large quantities of metal .

Coreless induction melting furnace

The name of the coreless induction melting furnace is relative in the cored induction furnace, and the metal liquid is in a crucible, so it is also named crucible furnace. This type furnace is mainly used for special steel, cast iron, non-ferrous metal and its alloy smelting and preserving heat. Coreless furnaces are many advantages, such as high melting temperature, less impurity contamination, alloy composition uniformity, good working conditions and many others. It Compares with cored induction furnace, it is easy to start the furnace and change the metal, it is more flexible, but its electrical and thermal efficiency, is far less than cored induction furnace. Because of the low surface temperature, it is inapplicable for high temperature smelting slag making process

                                                              COOLDO TECHNICAL DEPT

The Difference Between Closed and Open Circuit Cooling Tower Systems

The Difference Between Closed and Open Circuit Cooling Tower Systems

A cooling tower is used to cool and circulate water used in settings such as induction heating machine, induction melting machine and other plants, Cooling towers extract waste heat to the atmosphere through the cooling of a water stream to a lower temperature.

There are two different types of cooling towers: closed circuit cooling towers, and open circuit cooling towers. Both types of towers serve the same purpose, but they go about cooling the water in different ways.

A open circuit cooling tower is an enclosed structure that distributes warm water over a labyrinth-like packing or fill, which provides an expanded air-water interface for heating of the air and evaporation to take place. The water is cooled as it falls through the fill, and is then collected in a cold water basin below. The heated moisture-laden air leaving the fill is discharged into the atmosphere.

  

A closed circuit cooling tower no contact between the air and the fluid being cooled. This tower has two separate fluid circuits, one in which the fluid is recirculated on the outside of the second circuit, which is a bundle of tubes through which the hot water is flowing. The air drawn through this cascading water provides evaporative cooling similar to an open cooling tower, except that the cooled water never makes direct contact with the air

Why SHANGHAI COOLDO INDUSTRIAL CO., LTD.

 make strong suggestion to use closed circuit cooling tower even though it much higher cost than the open circuit cooling tower ,

Because: 

1, The water never contact with the air, keeping the water clear.
2, The clear water can extend life-span of the machine.

                        3, Responding the call of Water conservation. 

COOLDO TECHNICAL DEPT.

2016-03-17

How to choose the induction heating machine

How to choose the induction heating machine.

According with the difference frequency of alternating current output, we can divide into 5 kinds of induction heating machine.

Please let us know the items as below. 

1 , The shape and size of workpiece

• Big workpiece, bar, solid material, should use big power but low frequency induction heating machine.
• Small workpiece, Tube, plate material, gear should use small power but high frequency induction heating machine.2 , The heating depth and area.       

• Deepest, large area, bulk heating should use big power and low frequency induction heating machine.
• Small Deep,small area, partial heating should use small power and high frequency induction heating machine.

3 , Heating speed.         

• If need high speed, should us big power and high frequency induction heating machine.
• 4, Continuous working time

• If Long time using, should using a little big power induction heating machine.
• 5, other technological requirement

COOLDO TECHNICAL DEPT.2016-04-06

An Induction Furance

An Induction Furnace

Overview

An induction furnace is an electrical furnace in which the heat is applied by induction heating of metal. Induction furnace capacities range from less than one kilogram to one hundred tonnes capacity and are used to melt iron and steel,Copper,aluminium and precious metals.

The advantage of the induction furnace is a clean, energy-efficient and well-controllable melting process compared to most other means of metal melting. Most modern foundries  use this type of furnace, and now also more iron foundries are replacing cupolas with induction furnaces to melt cast iron, as the former emit lots of dust and other pollutants.

Type

In the coreless type,metal is placed in a crucible  surrounded by a water-cooled alternatiing current solenoid  coil. A channel-type induction furnace has a loop of molten metal, which forms a single-turn secondary winding through an iron core.

Operation

     An induction furnace consists of a non-conductive crucible holding the charge of metal to be melted, surrounded by a coil of copper wire. A powerful alternating current flows through the wire. The coil creates a rapidly reversing magnetic field  that penetrates the metal. The magnetic field induces eddy current, circular electric currents, inside the metal, by electromagnetic induction.The eddy currents, flowing through the electrical resistance of the bulk metal, heat it by Joule heating. In ferromagnetic materials like Iron, the material may also be heated by magnetic hysteresis, the reversal of the molecular magneti dipoles in the metal. Once melted, the eddy currents cause vigorous stirring of the melt, assuring good mixing. An advantage of induction heating is that the heat is generated within the furnace's charge itself rather than applied by a burning fuel or other external heat source, which can be important in applications where contamination is an issue.

Advantage to the others furnace

      Since no arc or combustion is used, the temperature of the material is no higher than required to melt it; this can prevent loss of valuable alloying elements. The one major drawback to induction furnace usage in a foundry is the lack of refining capacity; charge materials must be clean of oxidation products and of a known composition and some alloying elements may be lost due to oxidation (and must be re-added to the melt).

Please provide the items before pricing 

1, Operating frequencies range from utility frequency (50 or 60 HZ) to 400 kHz or higher

2,  The capacity (volume) of the furnace and the melting speed required. 

Generally, the smaller the volume of the melts, the higher the frequency of the furnace used; this is due to the skin depth which is a measure of the distance an alternating current can penetrate beneath the surface of a conductor. For the same conductivity, the higher frequencies have a shallow skin depth—that is less penetration into the melt. Lower frequencies can generate stirring or turbulence in the metal.

COOLDO MARKETING DEPT.

2016-04-07

The accident treatment when the induction furnace coil suddenly wear out, and the water pipe leakage

The accident of the Smelting furnace is difficult to predict,In face of  very sudden accident happened,we should be

 calm and adopt the correct treatment which can avoid the accident .

  First, power outage accident

 Due to power outages, the supply of water tin the coil stopped, the heat from the iron liquid is very large,If the lackage 

of the water for longtime , the water in the coil can become steam and do harm to coil cooling, Insulation and coil connected 

with the rubber tube and the coil will be  burned,Therefore, when the power outage, the sensor can be turned to industrial 

water or the start of a gasoline engine water pump,Because the furnace is  in a power outage, so the coil water content is one

 third compare with the furnace working condition, The outage time within one hour, using charcoal to cover the iron level, prevent

 heat, wait to power to come again.  Generally speaking, do not have to swing other measures, the temperature drop is also very

 limited.A 6 toncapacity induction furnace, power outage one hour, the temperature dropped only 50.    for the small capacity melting

 furnace ,the  outage time lasts for  more than one  hours, the iron liquid maybe solidified, So it is better when iron is still  liquid  , 

turn the pump power supply switch to the standby power supply, or use standby pump to get out iron liquid  by hand. But for various 

reasons, temporarily can't pour out the hot metal liquid , you can add some ferrosilicon postponed its solidification speed .If

 liquid iron already solidified, should try to damage the surface crust layer,dig a  hole to the inside,  to prevent gas explosion accident

 caused by thermal expansion during the second melting.   If power failure  time need  more than one day , there will be entirely 

solidification liquid iron, temperature also declined, even though the energizing melt, may not be electrified .Estimates as soon as 

possible, to determine a time of power outage in more than a day,  try to get out the metal liquid as soon as possible.

 Second, melting furnace iron liquid leakage

If Iron liquid leakage accident cause, easily casued equipment damage, even endangers  worker’s safety,

 so try to make the stove  maintenance work in daily life.

 When the leakage alarm bell rang, immediately cut off  the power supply, the inspector lining around, 

check if the iron liquid leakage,If leakage, immediately tilting  the furnace, emptied the molten iron . If there is no leak, 

 checks in accordance with procedures for 

examination and treatment.I f it is confirmed leaking liquid iron from the lining  cause the alarm, we  should pour molten iron  , 

repair the lining, or reramming,Drain liquid iron is due to the destruction caused by the lining,The thinner thickness of the

 crucible furnace is ,the  higher electrical efficiency will ne . But if  the wear lining thickness less than 65 mm,Throughout

 the lining thickness are almost  junction layers and buffer layers, there is no loose layer, lining will be slightly affected 

and produce small cracks, The cracks will be able to crack through the entire interior of the furnace, molten iron is easy to leak.

Third，Water cooling tower accident

 Usually the cooling water temperature is too high due to the following reasons: 1.Sensor

 Cooling water pipes blockage 2. water flow decreases.At this moment need power outage,

 use compressed air to blow pipes to remove foreign bodies,And the time stop the pump 

Had better not more than 15 minutes, Another reason is that the coil cooling water channel

 have scale, according to the cooling water quality situation, must put every use the hydrochloric 

acid to  pickling coil waterway 2 times each year. Melting furnace sensor conduit suddenly is leaking,

Leaking reason is that sensors around the magnetic yoke, or fixed bracket affected by the insulation

 breakdown, When found the accident immediately cut off the power, using epoxy resin or other insulating 

rubber seal the surface of leaks, Pour out the metel liquid ,and then repair the oven.  If coil water pipe

  is breakdown in large area, can't use epoxy resin to stop the leakage,  it had to stop the furnace, pouring

 the liquid iron, and repair.

      COOLDO TECHNICAL DEPT.

    2016-04-26