🔍 Key Concepts

• non-condensable gases behavior in evaporators and condensers • where air and gases tend to accumulate in a multi‑stage low pressure evaporator • purpose and location of an air ejector suction connection

💭 Think About

• In a multi‑stage evaporator, which component will have the lowest concentration of vapor and the highest tendency to trap air and other non‑condensables? • Think about where cooling/condensing takes place: where do non‑condensable gases end up when steam or vapor is condensed? • Which of the listed shells would be the most effective single point to remove gases from to improve overall heat transfer and vacuum?

✅ Before You Answer

• Identify which options are distilling condensers versus heaters or evaporator shells • Consider which stage (first or second) would see the greatest load of non‑condensables entering the system • Verify which location, if evacuated, would most improve vacuum and heat transfer efficiency throughout the evaporator system