Steam plant components — identify the device A vessel into which exhaust steam from an engine or turbine is led and condensed to water for reuse is called a:
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Asteam condenser
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Bsteam boiler
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Csteam preheater
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Deconomiser
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Edeaerator
Answer
Correct Answer: steam condenser
Explanation
Introduction / Context:Accurate component naming in a steam plant is essential. The device that collects exhaust steam and turns it back into water under vacuum is not the boiler or preheater; it is the condenser. Correct identification helps in understanding the Rankine cycle and the roles of each item.
Given Data / Assumptions:
- Exhaust steam leaves the prime mover at low pressure and enters a vessel.
- Inside, heat is removed, causing condensation.
- Condensate is recovered for boiler feed.
Concept / Approach:A steam condenser maintains sub-atmospheric pressure by condensing steam and extracting non-condensables. This lowers back pressure and increases net work output. The boiler, economiser, preheater, and deaerator have different locations and purposes in the cycle.
Step-by-Step Solution:Map function to component: condense steam → condenser.Other devices either generate steam (boiler) or preheat fluids (economiser for feedwater, preheater for air/steam) or remove dissolved gases (deaerator).Therefore, the correct choice is steam condenser.
Verification / Alternative check:Rankine cycle diagrams place the condenser between the turbine/engine exhaust and the feedwater pump, consistent with the description.
Why Other Options Are Wrong:
- Boiler: generates steam, not condense.
- Preheater/economiser: heat exchangers for steam/air or feedwater, but not for phase change of exhaust.
- Deaerator: strips dissolved gases; not the main condenser.
Common Pitfalls:Using “preheater” loosely for any heat exchanger; each device has a specific duty in the plant.
Final Answer:steam condenser