What occurs within the tubes of the device labeled "23" shown in the illustration? Illustration MO-0111

Correct Answer: Option C — The feed water flowing through the inside of the tubes is being heated by the jacket water on the outside of the tubes.

In this configuration, the device labeled '23' acts as a heat exchanger where engine jacket water circulates through the tubes to heat the incoming seawater. The heat transfer occurs from the hot jacket water inside the tubes to the cooler feedwater on the outside, facilitating the evaporation process within the unit.