CUPOLA FURNACE

Other Chapters

• Q1: What is a Cupola Furnace?
  Ans: A Cupola Furnace is a vertical, cylindrical furnace used in foundries for melting cast iron. It works on the principle of combustion of coke to generate heat for melting metal.
• Q2: State any two uses of Cupola Furnace.
  Ans: The uses of Cupola Furnace are:

  • ➔ Used for melting cast iron in foundries
  • ➔ Used for producing molten metal for casting operations
• Q3: State any four advantages of Cupola Furnace.
  Ans: Advantages of Cupola Furnace:

  • ➔ Simple construction and easy operation
  • ➔ High melting rate
  • ➔ Low operating cost
  • ➔ Continuous melting process
• Q4: State the components of Cupola Furnace.
  Ans: The main components of a Cupola Furnace are:

  • ➔ Shell
  • ➔ Charging door
  • ➔ Tuyeres
  • ➔ Tap hole
  • ➔ Slag hole
  • ➔ Blower
  • ➔ Tapping spout
• Q5: Briefly discuss the construction of Cupola Furnace.
  Ans: A Cupola Furnace consists of a vertical steel shell lined with refractory bricks.
  It has a charging door for adding materials, tuyeres for air supply, a tap hole for molten metal, and a slag hole for removing impurities.
  The bottom is supported by a drop-bottom door for cleaning and maintenance.
• Q6: Briefly discuss the working principle of Cupola Furnace.
  Ans: The working principle of a Cupola Furnace is based on combustion of coke with air blast.
  The charge (iron, coke, and flux) is added from the top.
  Air is blown through tuyeres which burns coke and produces high temperature heat.
  This heat melts the iron, and molten metal is collected at the bottom.
• Q7: What are Tuyeres used for in a Cupola Furnace?
  Ans: Tuyeres are used to supply air into the furnace to support combustion of coke and maintain high temperature inside the Cupola Furnace.
• Q8: What is the Sight Hole used for in a Cupola Furnace?
  Ans: The sight hole is used to observe the inside condition of the furnace during operation.
• Q9: What is the Charging Door used for in a Cupola Furnace?
  Ans: The charging door is used to add raw materials like iron, coke, and flux into the furnace.
• Q10: What is the Tap Hole used for in a Cupola Furnace?
  Ans: The tap hole is used to collect and discharge molten metal from the furnace.
• Q11: What is the Shell used for in a Cupola Furnace?
  Ans: The shell is the outer cylindrical steel structure that supports the refractory lining and all furnace components.
• Q12: What is the Slag Hole or Spout used for in a Cupola Furnace?
  Ans: The slag hole or spout is used to remove slag (impurities) formed during melting of metal.
• Q13: What is the Tapping Spout used for in a Cupola Furnace?
  Ans: The tapping spout is used to guide molten metal safely from the furnace into ladles or moulds.
• Q14: What is the Blower used for in a Cupola Furnace?
  Ans: The blower is used to supply a continuous stream of air into the furnace through tuyeres to support combustion.
• Q15: What is Cupola Charge?
  Ans: Cupola charge refers to the mixture of raw materials such as pig iron, coke, and flux that is fed into the furnace for melting.
• Q16: State any four properties of Cupola Charge.
  Ans: Properties of Cupola charge:

  • ➔ Proper size and shape for uniform melting
  • ➔ Free from moisture and dirt
  • ➔ High carbon content in coke
  • ➔ Suitable chemical composition of iron
• Q17: Name the flux used in the Cupola Furnace.
  Ans: The flux used in Cupola Furnace is limestone (CaCO₃).
• Q18: Briefly explain the Charging of Cupola.
  Ans: Charging of Cupola means adding layers of raw materials into the furnace.
  The charge is added in alternate layers of iron, coke, and flux through the charging door.
  This helps in proper melting and efficient combustion.
• Q19: Briefly explain the Tapping and Botting of Cupola.
  Ans: Tapping is the process of removing molten metal through the tap hole.
  Botting is the process of closing the tap hole using a bott stick and clay after tapping is completed.
• Q20: What is a Bott Stick?
  Ans: A bott stick is a tool used to close the tap hole of the Cupola Furnace after tapping molten metal.
• Q21: What is Botting Clay?
  Ans: Botting clay is a refractory clay used along with a bott stick to seal the tap hole of the Cupola Furnace.
• Q22: What is Slag Hole Tapping?
  Ans: Slag hole tapping is the process of removing slag from the furnace through the slag hole during melting operations.
• Q23: What is the Melting Zone in Cupola Furnace?
  Ans: The melting zone is the region inside the Cupola Furnace where the solid metal charge melts due to high temperature generated by burning coke.
• Q24: Briefly explain Melting and Pouring in a Cupola Furnace.
  Ans: In melting, the metal charge is heated and converted into molten state in the furnace.
  In pouring, the molten metal is collected from the tap hole and transferred into moulds through ladles for casting.