Esempio n. 1
0
def Stichlmair_flood(Vl,
                     rhog,
                     rhol,
                     mug,
                     voidage,
                     specific_area,
                     C1,
                     C2,
                     C3,
                     H=1.0):
    r'''Calculates gas rate for flooding of a packed column, using the
    Stichlmair [1]_ correlation. Uses three regressed constants for each
    type of packing, and voidage and specific area.

    Pressure drop is given by:

    .. math::
        \frac{\Delta P_{irr}}{H} = \frac{\Delta P_{dry}}{H}\left(\frac
        {1-\epsilon + h_T}{1-\epsilon}\right)^{(2+c)/3}
        \left(\frac{\epsilon}{\epsilon-h_T}\right)^{4.65}

    .. math::
        h_T = h_0\left[1 + 20\left(\frac{\Delta Pirr}{H\rho_L g}\right)^2\right]

    .. math::
        Fr_L = \frac{V_L^2 a}{g \epsilon^{4.65}}

    .. math::
        h_0 = 0.555 Fr_L^{1/3}

    .. math::
        c = \frac{-C_1/Re_g - C_2/(2Re_g^{0.5})}{f_0}

    .. math::
        \Delta P_{dry} = \frac{3}{4} f_0 \frac{1-\epsilon}{\epsilon^{4.65}}
        \rho_G \frac{H}{d_p}V_g^2

    .. math::
        f_0 = \frac{C_1}{Re_g} + \frac{C_2}{Re_g^{0.5}} + C_3

    .. math::
        d_p = \frac{6(1-\epsilon)}{a}

    Parameters
    ----------
    Vl : float
        Superficial velocity of liquid, Q/A [m/s]
    rhog : float
        Density of gas [kg/m^3]
    rhol : float
        Density of liquid [kg/m^3]
    mug : float
        Viscosity of gas [Pa*s]
    voidage : float
        Voidage of bed of packing material []
    specific_area : float
        Specific area of the packing material [m^2/m^3]
    C1 : float
        Packing-specific constant []
    C2 : float
        Packing-specific constant []
    C3 : float
        Packing-specific constant []
    H : float, optional
        Height of packing [m]

    Returns
    -------
    Vg : float
        Superficial velocity of gas, Q/A [m/s]

    Notes
    -----
    A numerical solver is used to solve this model.

    Examples
    --------
    Example is from [1]_, matches.

    >>> Stichlmair_flood(Vl = 5E-3, rhog=5., rhol=1200., mug=5E-5,
    ... voidage=0.68, specific_area=260., C1=32., C2=7., C3=1.)
    0.6394323542746928

    References
    ----------
    .. [1] Stichlmair, J., J. L. Bravo, and J. R. Fair. "General Model for
       Prediction of Pressure Drop and Capacity of Countercurrent Gas/liquid
       Packed Columns." Gas Separation & Purification 3, no. 1 (March 1989):
       19-28. doi:10.1016/0950-4214(89)80016-7.
    '''
    guess = [Vl * 100., 1000.0]
    return newton_system(_Stichlmair_flood_f_and_jac,
                         x0=guess,
                         jac=True,
                         args=(Vl, rhog, rhol, mug, voidage, specific_area, C1,
                               C2, C3, H),
                         ytol=1e-11)[0][0]
Esempio n. 2
0
def Stichlmair_flood(Vl, rhog, rhol, mug, voidage, specific_area, C1, C2, C3,
                     H=1.0):
    r'''Calculates gas rate for flooding of a packed column, using the
    Stichlmair [1]_ correlation. Uses three regressed constants for each
    type of packing, and voidage and specific area.

    Pressure drop is given by:

    .. math::
        \frac{\Delta P_{irr}}{H} = \frac{\Delta P_{dry}}{H}\left(\frac
        {1-\epsilon + h_T}{1-\epsilon}\right)^{(2+c)/3}
        \left(\frac{\epsilon}{\epsilon-h_T}\right)^{4.65}

    .. math::
        h_T = h_0\left[1 + 20\left(\frac{\Delta Pirr}{H\rho_L g}\right)^2\right]

    .. math::
        Fr_L = \frac{V_L^2 a}{g \epsilon^{4.65}}

    .. math::
        h_0 = 0.555 Fr_L^{1/3}

    .. math::
        c = \frac{-C_1/Re_g - C_2/(2Re_g^{0.5})}{f_0}

    .. math::
        \Delta P_{dry} = \frac{3}{4} f_0 \frac{1-\epsilon}{\epsilon^{4.65}}
        \rho_G \frac{H}{d_p}V_g^2

    .. math::
        f_0 = \frac{C_1}{Re_g} + \frac{C_2}{Re_g^{0.5}} + C_3

    .. math::
        d_p = \frac{6(1-\epsilon)}{a}

    Parameters
    ----------
    Vl : float
        Superficial velocity of liquid, Q/A [m/s]
    rhog : float
        Density of gas [kg/m^3]
    rhol : float
        Density of liquid [kg/m^3]
    mug : float
        Viscosity of gas [Pa*s]
    voidage : float
        Voidage of bed of packing material []
    specific_area : float
        Specific area of the packing material [m^2/m^3]
    C1 : float
        Packing-specific constant []
    C2 : float
        Packing-specific constant []
    C3 : float
        Packing-specific constant []
    H : float, optional
        Height of packing [m]

    Returns
    -------
    Vg : float
        Superficial velocity of gas, Q/A [m/s]

    Notes
    -----
    A numerical solver is used to solve this model.

    Examples
    --------
    Example is from [1]_, matches.

    >>> Stichlmair_flood(Vl = 5E-3, rhog=5., rhol=1200., mug=5E-5,
    ... voidage=0.68, specific_area=260., C1=32., C2=7., C3=1.)
    0.6394323542746928

    References
    ----------
    .. [1] Stichlmair, J., J. L. Bravo, and J. R. Fair. "General Model for
       Prediction of Pressure Drop and Capacity of Countercurrent Gas/liquid
       Packed Columns." Gas Separation & Purification 3, no. 1 (March 1989):
       19-28. doi:10.1016/0950-4214(89)80016-7.
    '''
    guess =  [Vl*100., 1000.0]
    return newton_system(_Stichlmair_flood_f_and_jac, x0=guess, jac=True,
                         args=(Vl, rhog, rhol, mug, voidage, specific_area, C1, 
                         C2, C3, H), ytol=1e-11)[0][0]