$19$:$27$

QUESTION $1$:PUMP SELECTION AND SIIING

$25$ MARKS

$74$

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Fractionator

S$301$

Methanol is to be used as an entrainer in an azeotropic fractionator. Liquid ethanol is pumped from a storage tank on ground floor to a reactor on level $2$ at height $Z_2$ using a centrifugal pump. The lowest liquid level in the tank is not allowed to go below the height of $Z_1.$ Line segment $L_1$ from the tank to the pump is a $3\frac{1}{2}$ inch schedule $40$ commercial steel, and is $20m$ long from the tank outlet to the pump inlet. This line segment has $390$ standard long elbows and $1$ globe valve that is fully open. Line segment $L_2$ from the pump outlet to the fractionator inlet is also a $3\frac{1}{2}$ inch schedule $40$ commercial steel, and is $90m$ long. The Segment $L1$ has $590$ standard long elbows and $2$ globe valve that is fully open, $4$ gate valves $(2$ fully open, $2\frac{1}{2}$ open$).$ The tank and fractionator are both at atmospheric pressure. The flowrate of methanol is $24$ tonnes$/$hr$.$ Estimate the power required by the pump by performing the following steps:

a$)$ Calculate the design static head of the system $($head in $m)$

$1$

b$)$ Specify the piping dimensions of the system $($ID and OD in $mm)$

c$)$ Provide the design flow specifications for the pump i$.$e$.$ flowrate $(\frac{m^3}{h}r)$ and velocity $(\frac{m}{s})$

$4$

d$)$ Calculate the dynamic head of the system $($head in $m)$

$8$

e$)$ Calculate the power required by the pump motor

$[4]$

f$)$ If NPSH required by the pump is $6m,$ will the pump be able to do the required task?

$5$

$Z1=1m,Z2=5m,T=30C.$ Take the pump efficiency as $70\%.$

Thermophysical properties for temperatures ranging $-50-150C$ are given in a table below:

Advanced Process Design EHAPD$4$A

April $2024$

Page $2$ of $3$

Teaching, Learning and Quality Assurance $2024$

ASSESSMENT $1$

Table $2$: Thermophysical properties of Methanol

$\backslash$table$[[\backslash$table$[[$Temperature$],[($:$C\}$