QUESTION $1$

A process stream, with an inlet temperature of $110$ C is to be cooled to $48$ C$.$ The

process stream has a flowrate of $33000$ kg$/$h$.$ Cooling water is available at $25$ C for

cooling purposes. The cooling water outlet temperature should not exceed $36$ C$.$

The physical properties of the process and cooling water stream are as follows:

Process stream Cooling water

Density $($kgm$3$

$)732992$

Heat capacity $($Jkg$1$

K$1$

$)33204190$

Viscosity $($Nsm$2$

$)3\mathrm{.}710-48\mathrm{.}010-4$

Thermal conductivity $($Wm$1$

K$1$

$)0\mathrm{.}1360\mathrm{.}613$

Fouling coefficient $($W m$-2$

K$1$

$)60003000$

Allowable pressure drop $($kPa$)6060$

Tubes $($k $=45$ Wm$1$

K$1$

$)$ with an outside diameter $($OD$)=19\mathrm{.}05$ mm$,$ wall thickness

of $2$ mm and length $=4\mathrm{.}88$ m$,$ are available. A triangular pitch of $1\mathrm{.}25$ OD has been

selected.

$1\mathrm{.}1.$ Would you agree that the cooling water stream should be allocated to the tube$-$

side of the exchanger? Justify your answer. $(2)$

$1\mathrm{.}2.$ Decide whether a $1$ shell $2$ tube pass heat exchanger will be suitable, and then

calculate the heat transfer area required for the heat exchanger, based on an

overall heat transfer coefficient of $650$ W$/$m$2$

K$.(9)$

$1\mathrm{.}3.$ Select the type of exchanger $($i$.$e$.$ fixed$-$tube, split$-$ring floating head, pull$-$

through floating head$)$ and calculate the shell bundle clearance and the shell

diameter required for the given service. $(8)$

NB: Shell$-$bundle chart on the last page!

$1\mathrm{.}4.$ Calculate the tube$-$side heat transfer coefficient, jh $=3\mathrm{.}6$ x $10-6$

$.(10)$