Autotherm Equipments Corporation is well known manufacturer,exporter and supplier of Cokeless Cupola Furnaces at market leading price from Coimbatore,, . EcoMelt Cokeless Melting Furnace is a Vertical Shaft Melting furnace and was as a melting unit for Cast iron without use of coke as in a conventional cupola. The development of the cokeless cupola began in the United Kingdom at the foundry of Hayes Shell Cast Limited in the mid s. A pilot furnace was built.

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It is sometimes necessary to add further materials such as a fluorspar which makes the slag more reactive to the ash so that both better carbon pick-up and better temperatures in the furnace can be obtained. This means that an operator continually has to release the cokeles by breaking the crust on the top of the box with a suitable bar, which is hot and heavy work.

US5294243A – Method of operating cokeless cupola – Google Patents

Accordingly, the exhaust gas contains high concentrations of carbon monoxide. Running the furnace at low slag volumes makes the slag thick and can cause blockage of the slagging and tapping box. Sprayable basic refractory composition for repairing the hot basic refractory linings of high temperature furnaces, and method.

Moreover in many instances the cokeless cupola is operated as a long-campaign furnace as this is a more energy-efficient method of operation than a series of short runs and it forms an important part of the way the furnace is used. This can reach the point where, in a bad condition, the slag can be blown back up the furnace shaft, causing severe operational difficulties and in the worst case the melting of the metal ceases altogether as the metallic charge becomes coated with the viscous slag.

We have discovered that slag control is essential to the correct operation of a cokeless cupola as opposed to being of minor importance as was previously felt. This avoids handling difficulties.

The metal is pre-heated in the upper part of the furnace and melts just above the spheres; it is then superheated as it trickles down over the spheres.


Once a cupola has been converted to Cokeless Melting Furnace, the foundry would be in a position to produce ductile iron and some graded iron without the need for an electric furnace. Year of fee payment: The cokeless cupola completely eliminates the use of coke for melting iron with substitution by natural gas, propane, diesel oil or other suitable fuels, even powdered coal is possible.

With correct charge materials the sulphur content of tapped iron can be below 0. In both cases the amount of recarburiser depends on charge makeup and final analysis required. United States Patent The metal is superheated as it trickles over the spheres. This avoids handling difficulties. Each burner has its own gas, air and oxygen valves for precise regulation of burner performance. It follows that less slag is made and hence there are less disposal problems.

The oxidation losses are lower than in a coke-fired furnaces so again, from this aspect, less flux is required. Difficulties arose through bridging of the metal, and the slag was very sticky. An electric furnace is not a very efficient melting unit but once the metal is liquid the superheating of the iron is very efficient. The flux addition will also depend on whether the furnace is to be tapped intermittently in which case a relatively low volume of slag can be handled, or is to be continuously tapped, in which case a higher slag volume is necessary for smooth operation.

Cokeless Cupola

EXAMPLE II A cokeless cupola operating with a clean charge and with what turnace mistakenly thought to be cokelesz proportions in the charge including 12 Kg of dollastone per charge was found to exhibit very rapid consumption of the spheres, with the consequence that the bed almost vanished by the end of an eight-hour shift, resulting in insufficient superheating and low metal temperature. A method according to claim 11 wherein sufficient flux materials are added to the melt to keep the viscosity of the slag below a critical value at which point the slag tends to be held above the heat-exchange bodies and has difficulty in flowing through the bed.

The cost will vary depending on type of metal being produced and whether graphite or a cheaper recarburiser is used in the process. Care must be taken not to add too much slag-forming materials. A method according to claim 1 which further comprises the step of re-cycling slag removed from the furnace by re-introducing at least a portion of the slag as a component of the slag-forming fluxing agents.


The rate of injection can be controlled. Difficulties arose through bridging of the metal, and the slag was very sticky.

In a cokeless cupola lined with a high alumina material, and operated for one week without repair although melting on only a single shift, the quantity of dollastone added to take care of the dirt, and the products of wear on the spheres and the wear on the lining was of the order of 2 to 2.

Gas is becoming available at various locations through out the country. He will also appreciate the greater flexibility of operation compared with the coke cupola. This means that an operator continually has to release the slag by breaking the crust on the top of the box with a suitable bar, which is hot and heavy work.

If insisted by the authority, a simple low cost wet cap may be installed to further reduce the emission level. The flux additions must also melt above the bed and these additions are likewise superheated in passing down over the spheres. In addition most cupola furnaces are lined with a refractory material and as this gradually wears away this material must also be absorbed into the slag.

This means higher dokeless of consumption of spheres.

Method of operating cokeless cupola – Cokeless Cupolas Limited

This invention relates to metal-melting furnaces, in particular cokeless cupola furnaces, and is concerned with control of the slag. For these foundries where expansion is being considered, the capital investment of installing a gas or oil fired Cokeless Melting Furnace could well be considerably less than adding additional electric furnaces.

It makes possible the production of high quality metal much easier for the foundryman, and hence his ability to produce good castings is much improved.

This is called duplexing.