A forward-feed triple-effect evaporator takes pineapple juice at 6.3 kg/s and produces 50% concentrate. Steam input is 2.48 kg/s at 121.1°C. Vapour flows from effects 1, 2 and 3 are 5675, 6053 and 6416 kg/hour. Find steam economy, to two decimals.
Steam economy is total water evaporated divided by fresh steam supplied. Evaporation=$(5675+6053+6416)/3600=5.04$ kg/s. Thus economy=$5.04/2.48=2.03226$, or **2.03 kg water/kg steam**. Inter-effect vapours are included as evaporation, but are not additional fresh steam inputs.
More Evaporation and Drying questions
GATE 2022 AG Q33– An osmo-dehydrated fruit slice has 72% moisture on wet basis. Find moisture on dry basis…
GATE 2022 AG Q62– Parboiled paddy dries from free moisture .40 to .02 kg water/kg dry solid. Dry solids99.8…
GATE 2022 AG Q65– A dryer recycles10 m³/s exhaust at 70°C,30% RH, humidity ratio .06335 kg/kg dry air. It…
GATE 2021 AG Q32– Fresh potatoes1000 kg are dried from 14% to 93% total solids. Peeling loses7% of original…
GATE 2021 AG Q62– Air at 40°C, total pressure101.3 kPa, contains water vapour at 4.0 kPa. Saturation vapour…
GATE 2026 AG Q45– A single-effect evaporator concentrates orange juice so product solids concentration/feed…