Chapter 5: Gas Laws

ILLUSTRATIVE EXAMPLE 5.1, Page number: 56

In [1]:
#Variable declaration:
qi = 3500                       #Initial volumetric flow rate of gas (acfm)
Ti = 100.0                      #Initial temperature (°F)
Tf = 300.0                      #Final temperature (°F)

#Calculation:
Ti_R = Ti+460                   #Initial temperatur in Rankine scale (°R)
Tf_R = Tf+460                   #Final temperatur in Rankine scale (°R)
qf = qi*(Tf_R/Ti_R)             #Final volumetric flow rate of gas (acfm)

#Result:
print "The final volumetric flow rate of gas is :",round(qf)," acfm"
The final volumetric flow rate of gas is : 4750.0  acfm

ILLUSTRATIVE EXAMPLE 5.2, Page number: 57

In [2]:
#Variable declaration:
qi = 3500                       #Initial volumetric flow rate of gas (acfm)
Pi = 1.0                        #Iitial pressure (atm)
Pf = 3.0                        #Final pressure (atm)

#Calculation:
qf = qi*(Pi/Pf)                 #Final volumetric flow rate of gas (acfm)

#Result:
print "The volumetric flow rate of the gas (100°F, 1 atm) is:",round(qf)," acfm"
The volumetric flow rate of the gas (100°F, 1 atm) is: 1167.0  acfm

ILLUSTRATIVE EXAMPLE 5.3, Page number: 57

In [4]:
#Variable declaration:
qi = 3500                       #Initial volumetric flow rate of the gas (acfm)
Pi = 1.0                        #Initial pressure (atm)
Pf = 3.0                        #Final pressure (atm)
Tf = 300.0+460.0                #Final temperature in Rankine scale (°R)
Ti = 100.0+460.0                #Initial temperature in Rankine scale (°R)

#Calculation:
qf = qi*(Pi/Pf)*(Tf/Ti)         #Final volumetric flow rate of the gas (acfm)

#Result:
print "The volumetric flow rate of the gas at 300°F temperature is :",round(qf)," acfm"
The volumetric flow rate of the gas at 300°F temperature is : 1583.0  acfm

ILLUSTRATIVE EXAMPLE 5.4, Page number: 59

In [5]:
#Variable declaration:
P = 14.7                    #Absolute pressure of air (psia)
MW = 29                     #Molecular weight of air (lb/lbmol)
T = 75+460                  #Temperature in Rankine scale (°R)
R = 10.73                   #Universal gas constant (ft^3.psi/lbmol.°R)

#Calculation:
p = P*MW/R/T                #Density of air (lb/ft^3)

#Result:
print "The density of air at 75°F and 14.7 psia is :",round(p,4)," lb/ft^3"
The density of air at 75°F and 14.7 psia is : 0.0743  lb/ft^3

ILLUSTRATIVE EXAMPLE 5.5, Page number: 59

In [6]:
#Variable declaration:
n = 1                           #Molar flow rate of gas (lbmol/h)
R = 10.73                       #Universal gas constant (ft^3.psi/lbmol.°R)
T = 60+460                      #Temperature in Rankine scale (°R)
P = 14.7                        #Absolute pressure of gas (psia)

#Calculation:
V = n*R*T/P                     #Volume of gas (ft^3)

#Result:
print "The volume of given ideal gas is :",round(V,1)," ft^3"
The volume of given ideal gas is : 379.6  ft^3

ILLUSTRATIVE EXAMPLE 5.6, Page number: 59

In [7]:
#Variable declaration:
P = 1.2                         #Abslute pressure of gas (psia)
MW = 29                         #Molecular weight of gas (g/gmol)
R = 82.06                       #Universal gas constant (atm.cm^3/gmol.K)
T = 20+273                      #Temperature in Kelvin (K)

#Calculation:
p = P*MW/R/T                    #Dendity of gas (g/cm^3)

#Result:
print "The density of given gas is :",round(p,5)," g/cm^3"
The density of given gas is : 0.00145  g/cm^3

ILLUSTRATIVE EXAMPLE 5.7, Page number: 60

In [7]:
#Variable declaration:
R = 10.73                       #Universal gas constant (psia . ft^3/lbmol .°R)
T = 70+460                      #Temperature in Rankine scale (°R)
v = 10.58                       #Specific volume (ft^3/lb)
P = 14.7                        #Absolute pressure (psia)

#Calculation:
MW = R*T/v/P                    #Molecular weight of gas (lb/lbmol)

#Result:
print "The molecular weight of the gas is :",round(MW,2)," lb/lbmol."
print "It appears that the gas is HCl (i.e., hydrogen chloride)."
The molecular weight of the gas is : 36.57  lb/lbmol.
It appears that the gas is HCl (i.e., hydrogen chloride).

ILLUSTRATIVE EXAMPLE 5.8, Page number: 61

In [9]:
#Variable declaration:
qs = 30000                      #Volumetric flow rate at standard conditions (scfm)
Ta = 1100+460                   #Actual absolute temperature in Rankine scale (°R)
Ts = 60+460                     #Standard absolute temperature in Rankine scale (°R)

#Calculation:
qa = qs*Ta/Ts                   #Volumetric flow rate at actual conditions (acfm)

#Result:
print "The volumetric flow rate in actual cubic feet per minute is :",round(qa),"  acfm"
The volumetric flow rate in actual cubic feet per minute is : 90000.0   acfm

ILLUSTRATIVE EXAMPLE 5.9, Page number: 62

In [10]:
#Variable declaration:
qs = 1000                       #Volumetric flow rate at standard conditions (scfm)
Ta = 300+460                    #Actual absolute temperature in Rankine scale (°R)
Ts = 70+460                     #Standard absolute temperature in Rankine scale (°R)
A = 2.0                         #Inlet area of stack (ft^2)

#Calculations:
qa = qs*Ta/Ts                   #Volumetric flow rate at actual conditions (acfm)
v = qa/A/60                     #Velocity of gas (ft/s)

#Result:
print "The velocity of the gas through the stack inlet is :",round(v)," ft/s"
The velocity of the gas through the stack inlet is : 12.0  ft/s

ILLUSTRATIVE EXAMPLE 5.10, Page number: 62

In [11]:
#Variable declaration:
qs1 = 5000.0                    #Volumetric flow rate of C6H5Cl at standard conditions (scfm)
qs2 = 3000.0                    #Volumetric flow rate of air at standard conditions (scfm)
Ta = 70+460.0                   #Actual absolute temperature in Rankine scale (°R)
Ts = 60+460.0                   #Standard absolute temperature in Rankine scale (°R)
V = 387.0                       #Volume occupied by one lbmol of any ideal gas (ft^3)
M1 = 112.5                      #Molecular weight of C6H5Cl (lb/lbmol)
M2 = 29.0                       #Molecular weight of air (lb/lbmol)
T = 60.0                        #Absolute temperature (°F)

#Calculations:
qa1 = qs1*(Ta/Ts)               #Volumetric flow rate of C6H5Cl at actual conditions (acfm)
qa2 = qs2*(Ta/Ts)               #Volumetric flow rate of air at actual conditions (acfm)
n1 = qa1/V                      #Molar flow rate of C6H5Cl (lbmol/min)
n2 = qa2/V                      #Molar flow rate of air (lbmol/min)
m1 = n1*M1*T                    #Mass flow rate of C6H5Cl (lb/h)
m2 = n2*M2*T                    #Mass flow rate of air (lb/h)
m_in = m1+m2                    #Total mass flow rate of both streams entering the oxidizer (lb/h)
m_out = m_in                    #Total mass flow rate of both streams exit the cooler (lb/h)

#Result:
print "The rate of the products exit the cooler is :",round(m_out)," lb/h"
The rate of the products exit the cooler is : 102634.0  lb/h

ILLUSTRATIVE EXAMPLE 5.11, Page number: 64

In [12]:
#Variable declaration:
p = 0.15                        #Partial pressure of SO3 (mm Hg)
P = 760.0                       #Atmospheric pressure (mm Hg)
m = 10**6                       #Particles in a million

#Calculation:
y = p/P                         #Mole fraction of SO3
ppm = y*m                       #Parts per million of SO3 (ppm)

#Result:
print "The parts per million of SO3 in the exhaust is :",round(ppm)," ppm ."
The parts per million of SO3 in the exhaust is : 197.0  ppm .