- class Flash(ID='', ins=None, outs=(), thermo=None, **kwargs)#
Create an equlibrium based flash drum with the option of having light non-keys and heavy non-keys completly separate into their respective phases. Design procedure is based on heuristics by Wayne D. Monnery & William Y. Svrcek . Purchase costs are based on correlations by Mulet et al.   as compiled by Warren et. al. .
Stream], optional) – Inlet fluid.
Stream], optional) –
 Vapor product
 Liquid product
P=None (float) – Operating pressure [Pa].
Q=None (float) – Duty [kJ/hr].
T=None (float) – Operating temperature [K].
V=None (float) – Molar vapor fraction.
x=None (float) – Molar composition of liquid (for binary mixtures).
y=None (float) – Molar composition of vapor (for binary mixtures).
vessel_material (str, optional) – Vessel construction material. Defaults to ‘Carbon steel’.
vacuum_system_preference ('Liquid-ring pump', 'Steam-jet ejector', or 'Dry-vacuum pump') – If a vacuum system is needed, it will choose one according to this preference. Defaults to ‘Liquid-ring pump’.
has_glycol_groups=False (bool) – True if glycol groups are present in the mixture.
has_amine_groups=False (bool) – True if amine groups are present in the mixture.
vessel_type=None ('Horizontal' or 'Vertical', optional) – Vessel separation type. If not specified, the vessel type will be chosen according to heuristics.
holdup_time=15.0 (float) – Time it takes to raise liquid to half full [min].
surge_time=7.5 (float) – Time it takes to reach from normal to maximum liquied level [min].
has_mist_eliminator (bool) – True if using a mist eliminator pad.
You may only specify two of the following parameters: P, Q, T, V, x, and y. Additionally, If x or y is specified, the other parameter must be either P or T (e.g., x and V is invalid).
>>> from biosteam.units import Flash >>> from biosteam import Stream, settings >>> settings.set_thermo(['Water', 'Glycerol'], cache=True) >>> feed = Stream('feed', Glycerol=300, Water=1000) >>> bp = feed.bubble_point_at_P() # Feed at bubble point T >>> feed.T = bp.T >>> F1 = Flash('F1', ... ins=feed, ... outs=('vapor', 'crude_glycerin'), ... P=101325, # Pa ... T=410.15) # K >>> F1.simulate() >>> F1.show(T='degC', P='atm') Flash: F1 ins...  feed phase: 'l', T: 100.67 degC, P: 1 atm flow (kmol/hr): Water 1e+03 Glycerol 300 outs...  vapor phase: 'g', T: 137 degC, P: 1 atm flow (kmol/hr): Water 958 Glycerol 2.32  crude_glycerin phase: 'l', T: 137 degC, P: 1 atm flow (kmol/hr): Water 42.4 Glycerol 298 >>> F1.results() Flash Units F1 Medium pressure steam Duty kJ/hr 4.81e+07 Flow kmol/hr 1.33e+03 Cost USD/hr 366 Design Vessel type Horizontal Length ft 8.46 Diameter ft 5.5 Weight lb 2.51e+03 Wall thickness in 0.312 Vessel material Carbon steel Purchase cost Horizontal pressure vessel USD 1.47e+04 Platform and ladders USD 3.22e+03 Heat exchanger - Floating head USD 4.48e+04 Total purchase cost USD 6.26e+04 Utility cost USD/hr 366
str, ...] = ('heat_exchanger', 'vacuum_system')#
class-attribute Name of attributes that are auxiliary units. These units will be accounted for in the purchase and installed equipment costs without having to add these costs in the
baseline_purchase_costsdictionary. Heat and power utilities are also automatically accounted for.
- property P#
Operating pressure (Pa).
- property vapor#
Outlet vapor stream (equivalent to outs).
- property liquid#
Outlet liquid stream (equivalent to outs).
class-attribute Name denoting the type of Unit class. Defaults to the class name of the first child class
All heat utilities associated to unit. Cooling and heating requirements are stored here (including auxiliary requirements).
Electric utility associated to unit (including auxiliary requirements).
All bare-module factors for each purchase cost. Defaults to values in the class attribute
All design requirements excluding utility requirements and detailed auxiliary unit requirements.
All baseline purchase costs without accounting for design, pressure, and material factors.
Itemized purchase costs (including auxiliary units) accounting for design, pressure, and material factors (i.e.,
F_M). Items here are automatically updated at the end of unit simulation.
All installed costs accounting for bare module, design, pressure, and material factors. Items here are automatically updated at the end of unit simulation.
Lifetime of equipment. Defaults to values in the class attribute
_default_equipment_lifetime. Use an integer to specify the lifetime for all items in the unit purchase costs. Use a dictionary to specify the lifetime of each purchase cost item.
Whether to run mass and energy balance after calling specification functions
Name-number pairs of baseline purchase costs and auxiliary unit operations in parallel. Use ‘self’ to refer to the main unit. Capital and heat and power utilities in parallel will become proportional to this value.