## Heat Balance Equations

(1) ABOVE TRAY (B-l) AND DEFINITION OF QC2-ENVELOPE III QC2=AQ'a-Qv(»-1)

(2) ABOVE TRAY B-ENVELOPE W Q*=AQ'(B-I) -(QVB +QHCOB)

PUMPAROUND CIRCULATION RATE LC2-Qcl/(c)[t(B-3)-i2j

HYDROCARBON PARTIAL PRESSURE ABOVE TRAY B P'HC -( PTB)[(L{» +l))/(L(a + l) + VB- Nl)]

Figure 4.6. Heat and material balance quantities—LCO draw tray.

b. Calculate the heat removal required in the mid-pumparound cooler to produce zero internal reflux from Tray B.

c. Calculate and tabulate the external heat quantities above Tray (B - 1).

d. Set the cooled pumparound liquid temperature at least 150 degrees lower than the Tray (B — 1) temperature and calculate the midpumparound circulation rate.

2. Tray B Balance-Envelope IV

a. At the assumed temperature, calculate the heat contents of the vapor and liquid streams leaving c.

Tray B. Note that the liquid is to be considered as only the product quantity. Calculate the reflux heat above Tray B. Calculate the heat absorbed in passing across Tray B by the liquid which is to be revaporized in the sidestream stripper.

Calculate the heat removal capability of the reflux available to Tray B.

Calculate the internal reflux from Tray (B + 1) and convert it to moles per hour. Calculate the partial pressure of product vapor in the total vapor rising from Tray B, neglecting the ft ft ft ft ft ft 