 I am Satish Parani working as an assistant professor in Vulture Institute of Technology, Sholapur. Today we will be learning about melting furnaces, specifically cupola. At the end of this session students will be able to understand cupola furnace in depth. These are the contents which will be for today's session. First important furnace used in melting, just an overview. Then second cupola furnace, then we will explain cupola construction details. Third one, steps which are involved in cupola furnace for melting practices. Finally, advantages of cupola furnace, then what are the disadvantages of cupola furnaces? Let us look at what are the important furnaces used in industries. First one is crucible furnace, second is cupola furnace, third one is electric arc furnace, fourth one is induction furnace, fifth one is electric resistance furnace, sixth one is rotary furnace, seventh one is river battery furnace. So these are all important furnaces which are being used in industry for ferrous and non ferrous melting practices. Also in some cases there is usage of two furnaces which we call as duplexing to take advantages of both the furnaces, specifically electric arc furnace or induction furnace used in conjunction with cupola furnace is called duplexing. To take advantages of both is called duplexing or triplexing. Let us start with cupola furnace. In cupola furnace it is old days and very simple kind of furnace used for melting, specifically cast iron. How the cupola word has derived? Cupola word is derived from the latin world called cupa which means cask or barrel. It is very much like a blast furnace. It is used to melt cast iron and steel both. Now let us explain what are the construction details used in cupola furnace. As you can see this is a shell type of lining is there which is made up of steel and the diameter is around 0.5 to 2.5 meters. Small cupola furnaces are cupolites and large cupola furnace are called cupolas. It depends upon the application or type of industry which type of furnace they are using. We can see there is a metal, flux and coke alternate layers are being placed over each other and at the bottom you can see at the left most there is a slag sprout. Please understand the slag is always at the top compared to the metal poured from the tapping center which is we can see in the figure which is on the right most side. This cupola furnace why slag is being at top because slag is lighter in weight so it has to be on top most position. Second there is a spark arrester which is placed at the top most position. Charging door can be throughout it we can see from the figure it is on the right side also left side also from where we can charge the furnace. Air blasts, twiers are also placed which are shown in the orange color which to blast the air. This is very simple kind of furnace which is being used for melting practices. Let us understand in short what are what is basic construction details. It is steel shell round 0.5 to 2.5 meter diameter. It rests on cast iron base with forelegs. Cupola generally have drop down doors. At bottom there is a tap hole to remove the metal as we shown as it is shown before and above that it is slag hole. Slag hole is always please understand slag hole is always placed above it because cupola because slag is lighter in weight. Twiers are used to introduce air into the furnace. Furnace has a opening halfway which is called a charging door from where it can be charged. Top of the stag is covered with the spark arrester. Steps now will understand what are the basic steps in operation of cupola. First one is preparation or repair if refractory lining. Refractory lining is if we are using for the first time it is prepared or if it we are using continuously it is to be repaired over a period of time. Lightning and burning of the coke bed. This is the important step to initialize the melting with the help of coke. There is a charging door. Charging door again I have we have seen in previous slide in the figure that the metal, coke and flux. These are the alternate layers which are placed with the help of this. Coke is being lighted and metal and flux is being used and then mixed together to produce the melting metal. Then the melting starts when we start the air blast. Then there is charging. Finally there is tapping and slagging. Tapping means metal is poured into laddles and laddles are immediately carried to the pouring point where the casting is filled with these metal and casting continuously fills in that. It is dropping the bottom. Now we have seen what are the construction details, what are the steps involved and now we'll see what are the advantages of cupola. The first and foremost advantage of cupola is the simplest construction as we see is the only furnace which is made in a very simple way. The cost as we can see it can be made 0.5 tons or even lesser than that two tons of metal can be done with the help of cupola. So the initial cost compared to the other furnaces is very very low. It is simple to operate as we have seen. There are alternate layers is being used and of coke metal and flux which are being charged and then simply the metal comes out. Next is the relatively it is a low operating cost. Why it is relatively low operating cost? Because manual labor is most involved in this. As manual labor is involved there is not much more automation involved and so simple melting practices are involved. So low operating cost per unit cost generally comes low compared to other type of furnaces. High melting rate is observed as I have told in the previous few minutes ago also that from small ton to tons of metal can be cast. Operated this can be operated continuously and no electric car is required. Now let us see what are the disadvantages of cupola? Close temperature control cannot is not possible. Carbon and sulphur pickup takes place which is called CI composition can be affected in that. Loss of iron, sulphur and manganese takes place is generally due to oxidization. Precise control is not possible which is help which is in case of induction furnace compared to induction furnace we can say. Environmental pollution even though there is power resistor, environmental pollution takes place. What are the references? Please refer to these are. We can refer the book called P.L.Gel which is also Foundry Technology and PTL Notes. Thank you.