HELP! Evaporator in series Problem

[Samzmom08]

Six Minutes (problem 63): In double effect evaporator, the following information is given:

Temperature of saturated steam from first effect - 220F

Temperature of second effect feed-70F

Temperature of final condenser-47F

U - overall heat transfer coefficient in both effects

A - contact area in both effects

My question is why is temperature of second effect = 110F, it isn't given in the problem?? What assumptions are made for this type of problem?

since Q1=Q2,

U1A1deltaT1 = U2A2deltaT2

delta T1 = Ts - T1

delta T2 = T1 - T2

solving for T1

 

[snickerd3]

I'll take a look when I get home, since I have the book there...

 

[snickerd3]

There was an errata for this problem. The revision was to change the final condenser temperature to 110 F

There were several errata that are listed on the website indicated in the back of the book.