Periodic (cyclic) furnaces—identify the example Which of the following installations operates on a periodic (cyclic) principle rather than a continuous steady mode?

Introduction / Context:
Thermal equipment can be continuous or periodic. Periodic (cyclic) units alternate between heating the checkerwork and delivering hot air/gases, while continuous units operate at steady conditions. Recognizing the operating principle helps in energy audits and control strategies.

Given Data / Assumptions:

• Items listed include stoves, furnaces, and kilns commonly found in ironmaking and coke production.
• Periodic operation implies a repeated sequence of heating and then delivering hot gas.

Concept / Approach:
Blast furnace stoves are classic regenerative heaters that cycle between 'on-gas' (heating checkers with fuel) and 'on-blast' (supplying hot blast air to the furnace). The blast furnace itself, coke oven chambers, and rotary kilns are continuous in their principal duty cycles (even though coke batteries are batched per oven, their heating flues run quasi-continuously across the battery).

Step-by-Step Solution:

Verification / Alternative check:
Hot-blast systems use at least two or three stoves cycling to maintain a continuous hot blast to the furnace while individual stoves alternate modes.

Why Other Options Are Wrong:

• Blast furnace: continuous counter-current reactor.
• Coke oven heating chamber: maintains continuous flue firing across the battery.
• Rotary kilns: continuous rotary processing.

Common Pitfalls:
Confusing batch charging in coking with periodic heating; the heating circuit itself is not cycled like stoves.

Final Answer:
Blast furnace stoves