What is the function of item 'D' shown in...

🔍 Key Concepts

• Flash-type evaporator / distilling unit flow path – where does jacket water go vs. where does seawater/feedwater go? • Difference between heating surfaces (to make vapor) and cooling/condensing surfaces (to turn vapor back to liquid). • Look at how item D is arranged relative to the vapor space and the condensate outlet.

💭 Think About

• Trace the path of the jacket water in the illustration: does item D carry jacket water, distillate, or seawater? • Ask yourself whether item D is located in the region where vapor forms, or where vapor is cooled and collected. • Compare item D to item B in the picture: do they perform the same function, or are they serving opposite parts of the cycle?

✅ Before You Answer

• Verify which side of the unit is the evaporator (heating) section and which side is the condenser (cooling) section. • Confirm whether item D has contact with vapor that needs to be cooled, or with seawater that needs to be heated. • Check if item D appears as a bundle of tubes with cooler liquid inside – a clue that it may act as a heat exchanger surface for condensation rather than for evaporation.

What is the function of item 'D' shown in the illustration? Illustration MO-0110

It heats the entering feed water.

It condenses the distillate

It heats the jacket water entering the device.

It causes the jacket water to evaporate.

🔍 Key Concepts

💭 Think About

✅ Before You Answer