🔍 Key Concepts

• Compare the disc-stack bowl shown to a tubular bowl with straight vertical surfaces used in older purifiers/separators • Think about how sludge is removed from each type of bowl during operation and whether the bowl must be stopped and dismantled • Notice the additional hydraulic/operating-water components and moving parts shown in the illustration and what function they usually serve

💭 Think About

• Look closely at the lower part of the bowl in the illustration: what does the shape and extra mechanism suggest about how solids are discharged? • For a tubular bowl with straight, vertical interior surfaces, how are accumulated solids normally taken out, and does that process happen with the machine running or stopped? • Which of the choices describes a fundamental design difference rather than a minor performance change like a specific rpm value?

✅ Before You Answer

• Identify how sludge leaves the illustrated bowl and ask whether this can occur without dismantling the bowl • Decide whether the main difference is about construction and operation or just about an assumed speed difference (rpm) that isn’t evident from the drawing • Confirm which option matches the purpose of the added hydraulic/actuating components visible around the bowl bottom and discharge area