Prime mover requirement: Must a compressor be driven by an external prime mover to operate under normal industrial conditions?

Introduction / Context:
A compressor is an energy conversion device. It does not create energy; it consumes shaft power and converts it into a higher enthalpy/pressure state of a working fluid. Recognizing the need for a prime mover is basic to power-train design and plant layout.

Given Data / Assumptions:

• Conventional compressors (reciprocating, screw, centrifugal, axial).
• Industrial setting requiring continuous, controllable operation.
• External prime mover options: electric motor, internal combustion engine, steam or gas turbine.

Concept / Approach:

From the First Law, the increase in fluid energy (primarily enthalpy for compressible flow) must be supplied by shaft work. Therefore, a compressor requires mechanical input from a prime mover. Self-acting “compressors” without external power are actually pressure boosters driven by another pressurized source (which itself required a prime mover upstream).

Step-by-Step Solution:

Verification / Alternative check:

Equipment nameplates list motor kW or engine hp; process simulators compute shaft input aligning with enthalpy rise and efficiency assumptions.

Why Other Options Are Wrong:

“Disagree” would violate energy conservation unless another hidden prime mover exists in the system boundary.

Common Pitfalls:

Confusing fluid-powered boosters or ejectors with true compressors; ignoring electrical power as the prime mover via motors.

Final Answer:

Agree