🔍 Key Concepts

• Flash-type evaporator operation in relation to seawater inlet temperature • Effect of vacuum level on boiling temperature and distillate quality • Relationship between feedwater temperature, shell temperature, and salinity of the distillate

💭 Think About

• How does colder seawater entering the system affect the energy required to bring it up to flashing temperature? • If vacuum becomes higher (pressure lower) than designed, what happens to the boiling process and the possibility of carryover of saltwater droplets? • Does colder feed tend to make distillate purer or less pure, and why?

✅ Before You Answer

• Compare how colder feedwater changes steam demand in the feed heater versus how it affects evaporator capacity. • Think about whether excessive vacuum alone automatically makes water purer, or if it can increase droplet carryover and raise salinity. • Ask: in real plant operations, when the seawater is very cold, what practical problem do engineers watch for in terms of distillate salinity?