import warnings
from CADETProcess.processModel import (
ChromatographicColumnBase,
FlowSheet,
Inlet,
Outlet,
Process,
)
[docs]
class FlipFlop(Process):
"""
Flip-flop process.
The flowsheet includes:
- feed: Inlet
- eluent: Inlet
- column: ChromatographicColumnBase
- outlet: Outlet
The process is configured with two injections and column flow direction flips:
- Injection 1 (duration: `feed_duration`)
- Flip column flow direction after `delay_flip`
- Injection 2 (delayed by `delay_injection`)
- Flip column flow direction back
"""
def __init__(
self,
column: ChromatographicColumnBase,
c_feed: list[float],
flow_rate: float,
feed_duration: float,
delay_flip: float,
delay_injection: float,
c_eluent: list[float] | float = 0.0,
) -> None:
"""
Initialize flip-flop process.
Parameters
----------
column : ChromatographicColumnBase
Chromatographic column object.
c_feed : list[float]
Feed concentration.
flow_rate : float
Flow rate.
feed_duration : float
Feed injection duration.
delay_flip : float
Time delay before flipping column flow direction.
delay_injection : float
Time delay before second injection.
c_eluent : list[float] | float | None, optional
Eluent concentration. Defaults to 0.0.
"""
if not isinstance(column, ChromatographicColumnBase):
raise TypeError("Expected ChromatographicColumnBase.")
if not column.name == "column":
warnings.warn("Renaming column to `column` for consistency")
column.name = "column"
flow_sheet = self._build_flow_sheet(
column=column,
c_feed=c_feed,
c_eluent=c_eluent,
)
super().__init__(flow_sheet, "FlipFlop")
self.cycle_time = 2 * (feed_duration + delay_flip + delay_injection)
# Durations
self.add_duration("feed_duration", feed_duration)
self.add_duration("delay_flip", delay_flip)
self.add_duration("delay_injection", delay_injection)
# Injection 1
self.add_event("feed_on_1", "flow_sheet.feed.flow_rate", flow_rate, 0)
self.add_event("eluent_off_1", "flow_sheet.eluent.flow_rate", 0.0)
self.add_event_dependency("eluent_off_1", ["feed_on_1"])
self.add_event("feed_off_1", "flow_sheet.feed.flow_rate", 0.0)
self.add_event_dependency("feed_off_1", ["feed_on_1", "feed_duration"], [1, 1])
self.add_event("eluent_on_1", "flow_sheet.eluent.flow_rate", flow_rate)
self.add_event_dependency("eluent_on_1", ["feed_off_1"])
# Flip backwards
self.add_event(
"backward_flow",
f"flow_sheet.{column.name}.flow_direction",
-1,
)
self.add_event_dependency("backward_flow", ["feed_off_1", "delay_flip"], [1, 1])
# Injection 2
self.add_event("feed_on_2", "flow_sheet.feed.flow_rate", flow_rate)
self.add_event_dependency("feed_on_2", ["backward_flow", "delay_injection"], [1, 1])
self.add_event("eluent_off_2", "flow_sheet.eluent.flow_rate", 0.0)
self.add_event_dependency("eluent_off_2", ["feed_on_2"])
self.add_event("feed_off_2", "flow_sheet.feed.flow_rate", 0.0)
self.add_event_dependency("feed_off_2", ["feed_on_2", "feed_duration"], [1, 1])
self.add_event("eluent_on_2", "flow_sheet.eluent.flow_rate", flow_rate)
self.add_event_dependency("eluent_on_2", ["feed_off_2"])
# Flip forwards
self.add_event(
"forward_flow",
f"flow_sheet.{column.name}.flow_direction",
1,
)
self.add_event_dependency("forward_flow", ["eluent_on_2", "delay_flip"], [1, 1])
def _build_flow_sheet(
self,
column: ChromatographicColumnBase,
c_feed: list[float],
c_eluent: list[float] | float = 0.0,
) -> FlowSheet:
"""Build and return the flow sheet for flip-flop process."""
component_system = column.component_system
# Unit Operations
feed = Inlet(component_system, name="feed")
feed.c = c_feed
eluent = Inlet(component_system, name="eluent")
eluent.c = c_eluent if c_eluent is not None else 0.0
outlet = Outlet(component_system, name="outlet")
# Flow Sheet
flow_sheet = FlowSheet(component_system)
flow_sheet.add_unit(feed, feed_inlet=True)
flow_sheet.add_unit(eluent, eluent_inlet=True)
flow_sheet.add_unit(column)
flow_sheet.add_unit(outlet, product_outlet=True)
flow_sheet.add_connection(feed, column)
flow_sheet.add_connection(eluent, column)
flow_sheet.add_connection(column, outlet)
return flow_sheet
