Mass Balance Problem (CM2110 material; Geankoplis 3rd ed 1.5-2):
Fish are
processed into fish meal and used as a supplementary protein
food.
In the processing the oil is first extracted to produce wet fish-cake
containing
80% water and 20% bone-dry cake. This wet cake feed is dried in
rotary
drum dryers to give a dry fish-cake product containing 40 wt%
water.
Finally the product is finely ground and packed. Calculate the
kg/h
of wet-cake feed needed to produce 1000 kg/h of dry fish-cake
product.
(solution)
Measurement of Pressure using fluid statics (CM2120 material;
Geankoplis 3rd ed
2.2-4) An open U-tube manometer is being used to measure the
absolute
presure (Pa) in a vessel containing air. The pressure
at the open end is atmospheric pressure, which is 754 mm Hg. The
liquid in the manometer is water having a density of 1000 kg/m3.
Assume the density of air is 1.30 kg/m3 . The reading
on the manometer is 0.415 m. Calculate the pressure of the air in
the vessel in psia and in kPa. (solution)
Derive the equation (shown below) for pressure difference DP
in a double-well manometer for the case where Ro=0, i.e. in
the case where, for DP=0, the levels in the
two sides of the two-fluid manometer are the same. HONORS PROBLEM:
Derive
the equation for the case where Ro0.
When would this happen? OLD
SOLUTIONNEW
SOLUTION
2.2-5 Measurement of Small Pressure Differences: Double well
manometer
(Geankoplis). The two-fluid U-tube manometer shown above is used
to measure the difference in pressure at two points in a line
containing
air at 1 atm abs pressure. When the pressure is the same on both
sides, the reading is zero. The lighter fluid is a hydrocarbon
with
a density of 812 kg/m3 and the heavier water has a density
of
998 kg/m3. The inside diameters of the U-tube and
reservoir
are 3.2 mm and 54.2 mm, respectively. The reading R of the
manometer
is 117.2 mm. Calculate the pressure difference in mm Hg and
pascals.(solution)
2.4-1 Calculation of shear stress in soybean oil (based on Geankoplis
3rd ed 2.4-1)
Soybean oil is confined between two very long, very wide parallel
plates.
The distance between the plates is 0.00914 m and the lower plate is
being
pulled at a relative velocity of 0.366 m/s greater than the velocity of
the top plate. The viscosity of the soybean oil is 4 X
10-2 Pa s at 303K. Make the following calculations: a)
calculate the shear stress and the shear rate using American
engineering
units (lbf, ft s); b) repreat using SI units; c) If glycerol at 293 K
having
a viscosity of 1.069 kg/m s is used instead of soybean oil, what
relative
velocity in m/s is needed using to achieve the same shear stress?
Assume that the gap between the plates remains the same. What is
the new shear rate? (solution)
(CM2120 material, Mechanical Energy Balance) Your grandfather has a
cottage
at the lake and needs to install a pump to feed water to the house. He
plans to pump water at night to fill a storage tank he has installed
next
to the cottage. The pipes and fittings he has chosen to use for the
installation
are listed in the table below. The pumps in the pumping catalog your
grandfather
has are rated by their value of horsepower (hp). What is the minimum
horsepower
rating of a pump capable of providing a flow rate of 5 gallons per
minute
of water at the tank? Assume the pump efficiency is 65% and that the
pipe
is PVC, i.e. completely smooth. SOLUTION
Type of fitting
Number of fittings of this type in Grandpa's water
system
0.
When would this happen? OLD
SOLUTION NEW
SOLUTION
