00000CH405121901

evaporator is 10 kPa. The overall heat-transfer coefficient is 1500 W/mK.

Calculate
(i) the boiling point elevation (2)
(ii) the steam consumption and the steam economy (7)
(iii) the heating surface area required (4)
(iv) Design all the parts of the evaporator (12)

Calculate the diameter, number of perforations, downspout area and net area of a
segmented sieve tray for the extraction of styrene from ethyl benzene using
diethylene glycol as solvent at 25°C and latm. The flow rate of hydrocarbon rich
phase is 1000 kg/h and solvent rich phase is 14500 kg/h. Hydrocarbon phase is
dispersed. The liquid properties are:

Density, kg/m

Viscosity, kg/m.s

/s

Diffusivity of styrene, m

Interfacial tension, N/m = 0.017

Distribution coefficient = (-९१,८०॥८८-०॥१,। 19.6

ok ok

Page 2082

(25)