化工原理英文习题及解答.doc

Problems and Solutions to Chemical
Engineering Principles

化工原理教研组编
Chapter 1 Fluid Mechanics
flame gas from burning the heavy oil is constituted of %CO2,,76%N2,8%H2O(in volume).When the temperature and pressure are 500℃and 1atm, respectively, calculate the density of the mixed gas .
Solution: The molecular weight of the gaseous mixture Mn is
Mn=My+ My+ My+ My
=44×+32×+28×+18×
=
Under 500℃,1atm,the density of the gaseous mixture is
ρ==×=³
reading of vacuum gauge in the equipment is 100mmHg,try to calculate the absolute pressure and the gauge pressure, respectively. Given that the atmospheric pressure in this area is 740mmHg.
Solution: The absolute pressure in the equipment is equal to that atmosphere pressure minus vacuum
P(absolute)=740―100
=640mmHg
=640×=×10N/m²
The gauge pressure=-vacuum =-100mmHg
=-(100×)=―×10N/m²
or the gauge pressure=-(100××10)=―×10N/m²
shown in the figure, the reservoir holds the oil whose density is 960kg/m³. The oil level is higher than the bottom of the reservoir. The pressure above the oil level is atmospheric pressure. There is a round hole(Φ760mm )at the lower half of the sidewall, the center of which is 800mm from the bottom of the reservoir.
The hand-hole door is fixed by steel bolts (14mm). If the working stress of the bolts is 400kgf/cm
2, how many bolts should be needed ?
Solution: Suppose the static pressure of the liquid on 0-0 level plane is p, then p is the average pressure of the liquid acting on the cover.
According to the basic hydrostatics equation
p=p+ρg h
The atmosphere pressure which acts on the outer flank of the cover is pa, then pressure difference between the inner flank and outer flank is
Δp=p―p= p+ρgh―ρgh
Δp =960×(―)=×10N/m²
The static pressure which acts on the cover is
Δp×=×10N/m2
The pressure on every screw is

the Number of screw=×10=
4. There are two