Question

Which of the following part is attached with an iron blast furnace to purge Hot Blast air?

• A. Ventury scrubber
• B. Tuyeres
• C. Bleeder valves
• D. Barrel

Hint:

Tuyeres are typically made of high-conductivity copper and designed with a double-walled jacket for water cooling to survive temperatures exceeding \( 2000^\circ\text{C} \) in the raceway.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks for the name of the component attached to an iron blast furnace that functions as the nozzle or conduit for injecting high-temperature preheated air (hot blast) into the furnace.

Step 2: Key Formula or Approach:
The blast furnace is a counter-current chemical reactor.
Preheated air is blown into the furnace near the bottom to combust carbon (coke) to generate carbon monoxide and heat:
\[ \text{C} + \text{O}_2 \rightarrow \text{CO}_2 \]
followed rapidly by:
\[ \text{CO}_2 + \text{C} \rightarrow 2\text{CO} \]

Step 3: Detailed Explanation:

• Function of Tuyeres: Tuyeres are heavy, water-cooled copper nozzles protruding through the furnace wall at the top of the hearth.
They receive highly preheated air (\( 1000^\circ\text{C} \text{ to } 1250^\circ\text{C} \)) from the bustle pipe and inject it into the active combustion zone (raceway).
To withstand the intense localized heat of the combustion zone, tuyeres must be continuously cooled by circulating high-pressure water.

• Auxiliary Fuel Injection: Modern tuyeres also incorporate lances to inject pulverized coal, natural gas, or fuel oil directly into the furnace to reduce coke consumption.

• Analysis of Other Options:
-

Ventury scrubber (Option A) is a gas-cleaning device used to remove fine dust from the blast furnace top gas.
-

Bleeder valves (Option C) are safety valves located at the top of the furnace to relieve sudden gas pressure surges.
-

Barrel (Option D) is a term not associated with the blast furnace hot blast distribution system.


Step 4: Final Answer:
Thus, the part attached to the furnace to inject hot blast air is the tuyeres, matching Option (B).