Which of the following is not an indirect contact heat exchanger?

Which of the following is not an indirect contact heat exchanger?

• A. Shell and Tube
• B. Plate and Frame
• C. Direct Contact
• D. Steam Surface Condenser

Answer: (C)

Heat transfer in exchangers can occur with or without a separating wall between the fluids. Indirect contact heat exchangers transfer heat through a solid boundary, so the two streams do not mix. Examples like shell-and-tube, plate-and-frame, and steam surface condenser all rely on walls or interfaces that keep the process and the cooling medium separate while heat passes through those walls. Direct contact heat exchangers have no separating barrier between the streams; the fluids are brought into direct contact and may mix as heat is transferred. Because there is no wall, this type is not an indirect contact exchanger. Therefore, the option that is not an indirect contact heat exchanger is the one where the fluids contact each other directly.

Heat transfer in exchangers can occur with or without a separating wall between the fluids. Indirect contact heat exchangers transfer heat through a solid boundary, so the two streams do not mix. Examples like shell-and-tube, plate-and-frame, and steam surface condenser all rely on walls or interfaces that keep the process and the cooling medium separate while heat passes through those walls.

Direct contact heat exchangers have no separating barrier between the streams; the fluids are brought into direct contact and may mix as heat is transferred. Because there is no wall, this type is not an indirect contact exchanger.

Therefore, the option that is not an indirect contact heat exchanger is the one where the fluids contact each other directly.