What is the shock bank?

• A. Section of tubes between convection and radiant sections
• B. A device to measure exhaust gas
• C. A filter for particulates
• D. A valve controlling fuel flow

Answer: (A)

The concept being tested is the transitional section of a boiler where the heat transfer path shifts from radiant to convection. In a fired boiler, heat from the flame first heats tubes in the radiant section, where radiation is the dominant heat transfer mechanism. As the hot flue gases move away from the flame, they enter the convection section, where heat is transferred mainly by convection around a bank of tubes.

A shock bank is the set of tubes positioned between these two sections. Its purpose is to smooth the flow and manage the rapid changes in gas velocity and temperature that occur as the gas moves from radiant to convection regions. By providing a transitional area, it helps distribute heat more evenly, reduces thermal and mechanical stresses on the tubes, and protects downstream sections from the intense, pulsing flow that can occur right after the radiant zone. It’s not a device for sensing exhaust, a filter, or a valve; it’s a structural part of the boiler’s heat‑transfer arrangement designed to cushion and balance the transition between the radiant and convection passes.