A double effect evaporator is used in feed forward mode to produce fresh water from sea water vontaining 3.5wt% dissolved salts. Sea water enters the first effect at 300K at a rate of 5000kg/hr, and saturated steam at a pressure of 4 bars is fed into a tube bundle in the 1st effect. The steam condenses at 4 bars and the condensate is withdrawn at the saturation temperature corresponding to this pressure.
The heat given up by the steam condensing in the tubes causes water to evaporate from the brine solution at the pressure of 0.6 bar maintained in the effect. The exiting brine contains 5.5% salt. The steam generated in the 1st effect is fed to a tube bumdle and the steam generated in the second effect at a pressure of 0.2 bar constitute the fresh water produced in the process.
a) draw and label a flow chart of the process, giving the temperature and specific enthalpy of each stream and tell at what rate must steam be fed to the 1st effect?