Chemical Engineering - Heat Transfer - Discussion

The right answer is [D], because when the heat transfer rate increases heat transfer co-efficient also increases.

If the heat transfer rate will increase then of course heat transfer coefficient will also increase.

The main role of baffles is to create turbulence flow, In turbulence flow, Reynold's number is higher and thus nusselt number is also high, and thus heat transfer coefficient is also high.

The main roles of a baffle in a shell and tube heat exchange are to:

1) Hold tubes in position (preventing sagging), both in production and operation.

2) Prevent the effects of vibration, which is increased with both fluid velocity and the length of the exchange.

3) Direct shell-side fluid flow along tube field. This increases fluid velocity and the effective heat transfer co-efficient of the exchange.