COKELESS CUPOLA FURNACE PDF
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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Gas is becoming available at various locations through out the country. It makes possible the production of high quality metal much cokelezs for the foundryman, and hence his ability to produce good castings is much improved. In particular where the lining of the furnace has a significant alumina content problems of excessive viscosity in the slag are almost certain unless steps are taken to adjust the composition of the flux accordingly, primarily by the addition of lime and magnesia, but where these are already at an acceptable level, scrap glass or gravel or other predominantly silica-containing materials must be added; generally speaking a high alumina content, whether from the incoming charge, the furnace lining or the spheres, will cause a high viscosity high melting-point slag unless counteracted by the measures described.
In particular where the lining of the furnace has a significant alumina content problems of excessive viscosity in the slag are almost certain unless steps are taken to adjust the composition of the flux accordingly, primarily by the addition of lime and magnesia, but where these are already at an acceptable level, scrap glass or gravel or other predominantly silica-containing cokless must be added; generally speaking a high alumina content, whether from the incoming charge, the furnace lining or the spheres, will cause a high viscosity high melting-point slag unless counteracted by the measures described.
A carbon injection unit, therefore, will be required which continually blows carbon into the cupola during melting. A method according to claim 1 wherein sufficient flux materials are added to the coksless 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.
US5294243A – Method of operating cokeless cupola – Google Patents
Features In a conventional coke fired cupola the coke has three functions. As this is a considerable growth area in India, it offers foundries an additional advantage over competitors who are still coieless a conventional coke cupola. It is therefore very important to control the flux additions in order to obtain the correct consistency of the slag so that the furnace can operate smoothly, but at an economic cost. Cold-blast cupola furnace In cold-blast cupolas, cold combustion air is supplied to the furnace as the exhaust gas is not cupoola recovered extraction above throatthis usually refers to small-sized furnaces melting rate of approx.
Because of the semi-permanent nature of the bed and the ability to control carbon content by injection as well as the precise control of the combustion process, both iron temperature and iron analysis cokeles far more consistent than that from a coke cupola.
In addition, the diagram shows that the furnace temperature in the combustion zone increases, while the throat gas temperature in a greater height above the nozzles remains the same.
Cokeeless melting point of the ckkeless was barely higher than the tapping temperature and so with a small stream of slag the stream tended freeze off altogether and had to be re-started.
Either way, the dripping zone in the furnace is independent of any fluctuations in pressure.
There is no ash to flux, furnaxe one of the main reasons for cpkeless a flux has been eliminated. This just goes to show that the “obvious” way of increasing slag volume – shovelling on several more shovels of limestone than is needed for our optimum method of operation results in excessive consumption of the spheres and subsequent decrease in the bed height and operational performance of the culola. As there is no carbon pickup in the Cokeless Melting Furnace, this is added either by continual injection into the well of the Cokeless Melting Furnace or outside in an electric furnace.
Instead it tends to be held above them and it then builds up in a layer above the spheres. According to a second aspect of the present invention we propose that if the slag volume is not sufficient to flow properly when required during tapping then a combination of limestone and silica is added to the charge to deliberately increase the volume so that the slag flows continuously and makes the operator’s job easier. As can be seen in Fig. The combination had a similar composition to what had been used previously, i.
According to a second aspect of the present invention we propose that if the slag volume is not sufficient to flow properly when required during tapping then a combination of limestone and silica is added to the charge to deliberately increase the volume so that the slag flows continuously and makes the operator’s job easier.
However there is still dirt in the charge and sand sticking to the returns, and so these materials still have to be converted into a fluid slag. As a result one of the existing 5 tonnes per hour cupolas was converted to a gas-fired cokeless system in November The quality of the fuel cokeHC coke and the combustion process itself must be reproducible since all fluctuations have an impact on the melting process. As a result, for same quantity of molten metal, much less CO 2 is emitted. At the same time, flux is still necessary to absorb the material originating from wear of the furnace lining and whilst in some cases a similar lining is used xokeless the action is therefore similar, the actual lining consumption is much less, so here again there is a difference resulting in a lower need for a flux.
It follows that less slag is made and hence there are less disposal problems. It can be extracted laterally from the furnace extraction below throat and thermally recovered. This cokelsss may involve deliberately increasing the volume of slag by suitable additions in order to operate a continuously tapped furnace smoothly. Advantages of the liningless furnace include a reduced lining effort and the somewhat longer furnace campaign, while long-term furnaces with a lining provide the benefit of lower cokelless losses, ultimately resulting in reduced coke consumption and better energy utilization associated with the above-mentioned benefits for the environment and the climate.
The depth of the bed of spheres governs the amount of superheat and therefore the tapping temperature. This normally results in excessive consumption of the heat-exchange bodies. However, we have appreciated that the types of flux materials generally employed in order to produce a fluid slag also attack the spheres, and that furrnace is very important to control the addition of fluxing agents.
The carbon content of the metal can be easily altered by changing the injection rate at the control panel. 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.
In the conventional coke-fired cupola furnace the importance of slag control is recognised and the mechanism is fairly well understood. However, with continuous tapping we have found that this low slag volume can cause operational problems as the slag does not flow continuously from the front tapping and slagging box.
Some examples will now be described to illustrate what can happen when a cokeless cupola is not run in accordance with the invention. Depending on the metallurgical requirements, the long-term furnace is equipped with a separate slag siphon or with a pressurized siphon. Difficulties arose through bridging of the metal, and the slag was very sticky.
A conventional coke cupola causes significant pollution. This is the purpose of the cpola of limestone to the charge in the furnace; the limestone acts as a flux to absorb all these unwanted materials and form a slag which can be easily removed from the furnace and handled outside.
Cokeless Cupola Furnaces Manufacturer,Cokeless Cupola Furnaces Exporter,Supplier in Coimbatore
This causes the iron to melt and being drained downwards. The heat in the counter flow is transferred to the top-fed material. Simpler more manual systems are also manufactured. A method according to claim 12 wherein limestone, dollastone is added to the re-cycled slag as another component of the ckpola agents.
Another way of deliberately increasing the volume of slag in the furnace is to re-cycle the slag. Picture shows metal being converted directly to ductile iron without desulphurisation.
However, with continuous tapping we have found that this low slag volume can cause operational problems as the slag does not flow continuously from the front tapping and slagging box.
The Cokeless Melting Furnace is operated with partially reducing conditions. 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.