def calc_umf_wenyu(self, gas):
"""
Calculate minimum fluidization velocity [m/s] based on the Ergun
equation.
"""
mug = gas.mu * 1e-7 # convert to kg/ms = µP * 1e-7
umf_wenyu = cm.umf_coeff(self.dp, mug, gas.rho, self.rho, coeff='wenyu')
return umf_wenyu
rhos = 2500 # density of bed particle [kg/m³] # air properties at T=300K and P=1atm -> rho=1.17 kg/m^3, ug=1.85e-5 kg/ms # N2 properties at T=773K and P=1atm -> rho=0.44 kg/m^3, ug=3.6e-5 kg/ms mu = 3.6e-5 # dynamic viscosity of gas [kg/ms] rhog = 0.44 # density of gas [kg/m³] # void fraction and sphericity for the Ergun equation ep = 0.46 # void fraction [-] phi = 0.86 # sphericity [-] # Umf calculations # ---------------------------------------------------------------------------- # Wen and Yu, Richardson, Saxena and Vogel, Babu, Grace, and Chitester umf_wenyu = cm.umf_coeff(dp, mu, rhog, rhos) umf_rich = cm.umf_coeff(dp, mu, rhog, rhos, 'rich') umf_sax = cm.umf_coeff(dp, mu, rhog, rhos, 'sax') umf_babu = cm.umf_coeff(dp, mu, rhog, rhos, 'babu') umf_grace = cm.umf_coeff(dp, mu, rhog, rhos, 'grace') umf_chit = cm.umf_coeff(dp, mu, rhog, rhos, 'chit') # Ergun function umf_ergun = cm.umf_ergun(dp, ep, mu, phi, rhog, rhos) # Small particles where Re < 20 umf_small_re = cm.umf_reynolds(dp, ep, mu, phi, 19, rhog, rhos) # Large particles where Re > 1000 umf_large_re = cm.umf_reynolds(dp, ep, mu, phi, 1001, rhog, rhos)
def test_umf_chit():
# minimum fluidization velocity [m/s]
umf = cm.umf_coeff(dp, mu, rhog, rhos, 'chit')
assert umf == approx(0.1443, rel=1e-2)
def test_umf_grace():
# minimum fluidization velocity [m/s]
umf = cm.umf_coeff(dp, mu, rhog, rhos, 'grace')
assert umf == approx(0.1259, rel=1e-2)
def test_umf_babu():
# minimum fluidization velocity [m/s]
umf = cm.umf_coeff(dp, mu, rhog, rhos, 'babu')
assert umf == approx(0.2136, rel=1e-2)
def test_umf_sax():
# minimum fluidization velocity [m/s]
umf = cm.umf_coeff(dp, mu, rhog, rhos, 'sax')
assert umf == approx(0.1879, rel=1e-2)
def test_umf_rich():
# minimum fluidization velocity [m/s]
umf = cm.umf_coeff(dp, mu, rhog, rhos, 'rich')
assert umf == approx(0.1192, rel=1e-2)
def test_umf_wenyu():
# minimum fluidization velocity [m/s]
umf = cm.umf_coeff(dp, mu, rhog, rhos)
assert umf == approx(0.1021, rel=1e-2)