Choking velocity

Stuff goes here.

Source code

chemics.choking_velocity.uch_bifan(ar, dp, gs, rhog)[source]

Choking velocity from Bi and Fan 1, also see Zhang 2015 paper.

Parameters
  • ar (float) – Archimedes number [-]

  • dp (float) – Diameter of particle [m]

  • gs (float) – Solids flux [kg/(s m^2)]

  • rhog (float) – Density of gas [kg/m^3]

Returns

uch (float) – Choking velocity [m/s]

References

1

Bi, Fan, 1991. Regime transitions in gas-solid circulating fluidized beds. AIChE Annual Meeting. AIChE, Los Angeles, pp. 17-22, 1991.

chemics.choking_velocity.uch_leung(us, ut)[source]

Choking velocity based on Equation 6 from Leung 2. All parameters must be in units of ft/s or in units of m/s.

Parameters
  • us (float) – Solids velocity [ft/s or m/s]

  • ut (float) – Terminal velocity of a single particle [ft/s or m/s]

Returns

uch (float) – Choking velocity [ft/s or m/s]

References

2

L.S. Leung, Robert J. Wiles, and Donald J. Nicklin. Correlation for Predicting Choking Flowrates in Vertical Pneumatic Conveying. Ind. Eng. Chem. Process Des. Develop., vol. 10, no. 2, pp. 183-189, 1971.

chemics.choking_velocity.uch_matsen(gs, rhos, ut)[source]

Choking velocity from the Matsen paper 3.

Parameters
  • gs (float) – Solids flux [kg/(s m^2)]

  • rhos (float) – Density of particle [kg/m^3]

  • ut (float) – Terminal velocity [m/s]

Returns

uch (float) – Choking velocity [m/s]

References

3

Matsen, 1982. Mechanism of Choking and Entrainment. Powder Technology, 32, 21-33.

chemics.choking_velocity.uch_psri(x, dp, d_pipe, gs, rhog, rhos, ut)[source]

Choking velocity from PSRI 2016 notebook. Uses MKS units for input parameters but returns Uch in ft/s. Function requires SciPy fsolve to solve for Uch.

Parameters
  • x (float) – Solve for Uch with SciPy fsolve

  • dp (float) – Particle size [m]

  • d_pipe (float) – Pipe diameter [m]

  • gs (float) – Solids mass flux [kg/(s m^2)]

  • rhog (float) – Density of gas [kg/m^3]

  • rhos (float) – Density of particle [kg/m^3]

  • ut (float) – Terminal velocity [m/s]

Returns

uch (float) – Choking velocity [ft/s]

References

Notebook from PSRI 2016 workshop, pages J-20 and J-72.

chemics.choking_velocity.uch_punwani(xy, d_pipe, gs, rhog, rhos, ut)[source]

Provide functions to solve for voidage and choking velocity based on equations from Punwani 1976. Requires SciPy fsolve function.

Parameters
  • xy – Solves for ep and uch using SciPy fsolve where ep = voidage [-] and uch = choking velocity [m/s]

  • d_pipe (float) – Internal pipe diameter [m]

  • gs (float) – Solids flux [kg/(s m^2)]

  • rhog (float) – Density of gas, must be in units of lb/ft^3

  • rhos (float) – Density of particle [kg/m^3]

  • ut (float) – Terminal velocity [m/s]

Returns

f1, f2 (functions) – Functions to solve for ep and uch

References

Punwani, Modi, Tarman, 1976. A Generalized Correlation for Estimating Choking Velocity in Vertical Solids Transport. Institute of Gas Technology, Chicago, IL, 1-14.

chemics.choking_velocity.uch_yang(xy, d_pipe, gs, rhos, ut)[source]

Provide functions to solve for voidage and choking velocity based on equations from Yang 1975. Requires SciPy fsolve function.

Parameters
  • xy – Solve for ep and uch using SciPy fsolve where ep = voidage [-] and uch = choking velocity [m/s]

  • d_pipe (float) – Internal pipe diameter [m]

  • gs (float) – Solids flux [kg/(s m^2)]

  • rhos (float) – Density of particle [kg/m^3]

  • ut (float) – Terminal velocity [m/s]

Returns

f1, f2 (fuctions) – Functions to solve for ep and uch

References

Yang, 1975. A Mathematical Definition of Choking Phenomenon and a Mathematical Model for Predicting Choking Velocity and Choking Voidage. AIChE Journal, 21, 5, 1013-1015.

chemics.choking_velocity.uch_yousfi(dp, gs, rhog, mu, ut)[source]

Choking velocity from Yousfi 1974, also see Zhang 2015 paper.

Parameters
  • dp (float) – Particle diameter [ft or m]

  • gs (float) – Solids flux [lb/(hr ft^2) or kg/(s m^2)]

  • rhog (float) – Gas density [lb/ft^3 or kg/m^3]

  • mu (float) – Gas viscosity [lb/(ft s) or kg/(s m)]

  • ut (float) – Terminal velocity of particle [ft/s or m/s]

Returns

uch (float) – Choking velocity [ft/s or m/s]

References

Yousfi, Gau, 1974. Aerodynamique De L’Ecoulement Verical De Suspensions Concentrees Gaz-Solides I. Regimes D’Ecoulement Et Stabilite Aerodynamique. Chemical Engineering Science, 29, 1939-1946.

chemics.choking_velocity.uch_zhang(ar, dp, gs, rhog)[source]

Choking velocity from Zhang 2015.

Parameters
  • ar (float) – Archimedes number [-]

  • dp (float) – Diameter of particle [m]

  • gs (float) – Solids flux [kg/(s m^2)]

  • rhog (float) – Density of gas [kg/m^3]

Returns

  • uch (float) – Choking velocity [m/s]

  • Reference

  • ———

  • Zhang, Degreve, Dewil, Baeyens, 2015. Operation diagram of Circulating

  • Fluidized Beds (CFBs). Procedia Engineering, 102, 1092-1103.