Feed Block#

Feed Blocks are used to represent sources of material in Flowsheets. Feed blocks do not require calculation of the phase equilibrium of the feed stream (some property packages, like the Modular Property Package with a FTPx state definition, always flash regardless), and the composition of the material in the outlet stream will be exactly as specified in the input. For applications where the users wishes the outlet stream to be in phase equilibrium, see the Feed_Flash unit model.

Degrees of Freedom#

The degrees of freedom of Feed blocks depends on the property package being used and the number of state variables necessary to fully define the system. Users should refer to documentation on the property package they are using.

Model Structure#

Feed Blocks consists of a single StateBlock (named properties), each with one Outlet Port (named outlet). Feed Blocks also contain References to the state variables defined within the StateBlock.

Additional Constraints#

Feed Blocks do not write any additional constraints to the model themselves. However, the StateBlock they contain may write constraints.


Feed blocks add no additional Variables.


class idaes.models.unit_models.feed.FeedInitializer(**kwargs)[source]#

Initializer for blocks with a single state (Feed, Product, StateJunction).

As these contain a single state block and nothing else, this Initializer just gets the default initializer for the State Block and uses that to initialize the State Block.


Tolerance for checking constraint convergence


Set output level for logging messages


Initialization routine for Feed Blocks.


model (Block) – model to be initialized



Feed Class#

class idaes.models.unit_models.feed.Feed(*args, **kwds)#
  • rule (function) – A rule function or None. Default rule calls build().

  • concrete (bool) – If True, make this a toplevel model. Default - False.

  • ctype (class) –

    Pyomo ctype of the block. Default - pyomo.environ.Block

    Config args


    Indicates whether this model will be dynamic or not, default = False. Feed blocks are always steady-state.


    Feed blocks do not contain holdup, thus this must be False.


    Property parameter object used to define property calculations, default - useDefault. Valid values: { useDefault - use default package from parent model or flowsheet, PhysicalParameterObject - a PhysicalParameterBlock object.}


    A ConfigBlock with arguments to be passed to a property block(s) and used when constructing these, default - None. Valid values: { see property package for documentation.}

  • initialize (dict) – ProcessBlockData config for individual elements. Keys are BlockData indexes and values are dictionaries with config arguments as keys.

  • idx_map (function) – Function to take the index of a BlockData element and return the index in the initialize dict from which to read arguments. This can be provided to override the default behavior of matching the BlockData index exactly to the index in initialize.


(Feed) New instance

FeedData Class#

class idaes.models.unit_models.feed.FeedData(component)[source]#

Standard Feed Block Class


Begin building model.






alias of FeedInitializer

initialize_build(state_args=None, outlvl=0, solver=None, optarg=None)[source]#

This method calls the initialization method of the state block.

Keyword Arguments:
  • state_args – a dict of arguments to be passed to the property package(s) to provide an initial state for initialization (see documentation of the specific property package) (default = None).

  • outlvl – sets output level of initialization routine

  • optarg – solver options dictionary object (default=None, use default solver options)

  • solver – str indicating which solver to use during initialization (default = None, use default solver)