Question

The process of stopping the furnace operation at the end of campaign is known as

• A. Fanning
• B. Back draughting
• C. Banking
• D. Blowing-out

Hint:

Associate the terms with the duration of the shutdown:

• Fanning = Very short term (hours)

• Banking = Short term (days)

• Blowing-out = Permanent (end of life, years)

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
A blast furnace "campaign" refers to its operational lifespan between two major shutdowns for relining the refractory bricks inside. This can last for 10-20 years. The question asks for the name of the controlled procedure used to shut the furnace down at the end of this long period.

Step 3: Detailed Explanation:
Let's define the operational terms given in the options:

• Fanning: A procedure for a very short stop (a few hours). The blast volume is significantly reduced but not stopped, just enough to keep the furnace hot and the tuyeres open.

• Back draughting: This is not a standard blast furnace operating term. It refers to a hazardous event in firefighting where a sudden introduction of air into a depleted-oxygen environment causes an explosion.

• Banking: A procedure for a temporary, planned shutdown (e.g., for a few days to a week). The furnace is filled with a special charge, typically with extra coke, the blast is stopped, and the furnace is sealed to conserve as much heat as possible for an easier restart.

• Blowing-out (or Blowing-down): This is the systematic and controlled process of shutting down the furnace at the end of its campaign life. It involves stopping the charging of ore and limestone while continuing to charge coke and blow air, gradually emptying the furnace of its contents over several days until it is safe to cool down for demolition and rebuilding.
Since the question specifies stopping the operation at the end of a campaign, the correct term is blowing-out.

Step 4: Final Answer:
The process of stopping the furnace operation at the end of its campaign life is known as blowing-out.