Question

A flow of methane is 8,000 scfm (standard cubic feet per minute). What is the mass flow rate in lbm/hour? What is the actual volumetric flow if the actual conditions are 112°F and 0.8 atm? Standard conditions are 1 atm and 59°F. Please report your answer to 4 significant digits. Assume the ideal gas law applies. The molecular weight of methane to 5 significant digits is 16.042 g/mol.

Answer 1

b)

actual conditions                        standard conditions

P1V1/T1                    = P2V2/T2

.8*V1/112               =     8000 * 1/59

So V1 = 8000*112/8*59 = 1898.05085 standard cubic feet per minute   = actual volumetric flow

a) scfm/lbm/h =(0.0807*.453/60)/0.45359/3600= 4.8357

So 1 scfm = 4.8357 lbm/h

so 8000 scfm = 8000*4.8357= 38685.6147 lbm/h