LT. = 0 = L.-.Z.
 1 i 1j

 LM.. = 0 = x.. -1 ./L.
 13 12 13 1

 Q 0= 1-E(x. .exp(A .+B .T ))
 j 3 3 37

 LE, = 0 = h.-L .(x. .(a .+b .T))

 E = 0 = H.i+h-H. -h -hf.
 I 1 1 I+l 1-1 i 1

 XY = 0 = y..-x..exp(A .+B .T.)
 2J 1J 1 J J 2

 VE. = 0 = Hi-V.(Ey .(c .+d.T.))
 1 2 i j 3 3 i

where

 v. = Vapor flow rate of component j leaving stage i (moles/hr.)
 -
 V. = Total vapor flow rate leaving stage i (moles/hr.)
 1

 yij = Mole fraction of component j in vapor leaving stage i

 =. = Liquid flow rate of component j leaving stage i (moles/hr.)

 fi. = Feed rate of component j to stage i (moles/hr.)

 L. = Total liquid flow rate leaving stage 1 (moies/hr.)

 xz. = Mole fraction of component j in liquid leaving stage .

 A.,B = Constants for calculating K-value for component j,
 3
 K. = exp(A +B T), K = Equilibrium constant.

 T. = Temperature on stage i (F)
 I
 h. = Enthalpy of liquid stream leaving stage J (BTU/hr.)
 1
 a ,b = Constants for calculating enthalpy of component j in liquid

 phase, h = lj(a .+b.T)

 H. = Enthalpy of vapor stream leaving stage i (BTU/hr.)

 c.,d. = Constants for calculating enthalpy of component j in vapor
 3 3
 phase, H = v (o +d jT)

 i = Stage number

 j = Component number.