A single-stage evaporator has a contact area of 30 m2. It is used to concentrate 4000 kg/h of NaOH solution from 10% to 40% that is fed at 60C. The hot utility is saturated steam that condenses at 115C. In the evaporation chamber, the total pressure is 20 mmHg. A flow of 4000 kg/h of steam is required for the operation; see Fig. P4.4.

Determine:

a. The heat loss as a ratio of the heat provided.

b. The global heat transfer coefficient.

Transcribed Image Text:

W (115C) E F (60C, 10%) 20mmHg W L (40%)