An aqueous solution with a mass flow rate of 9 000 kg/h is concentrated in an effect evaporator double with indirect contact (hot and cold fluids do not mix) with co-current supply from 15% (by mass) to 55%. Feed enters the first evaporator at 375K. O specific heat of the feed is 3.75 KJ/(K.kg). In the second effect, the operating pressure is 18 kPa. It is estimated that the concentrated solution undergoes an increase in its boiling temperature of 6 K. The pressure of the heating vapor entering the first effect is 240 kPa. You global heat transfer coefficients in the 1st and 2nd effect are, respectively: 1.8 and 0.63 kW/(m².K). Assume the effects have equal heating area, determine the area amount of heating used in the concentration.