import warnings
from CADETProcess.processModel import (
ChromatographicColumnBase,
FlowSheet,
Inlet,
Outlet,
Process,
)
[docs]
class LWE(Process):
"""
Load-Wash-Elute (LWE) process.
The flowsheet includes:
- load: Inlet (feed)
- salt_low: Inlet (low salt buffer)
- salt_high: Inlet (high salt buffer)
- column: ChromatographicColumnBase
- outlet: Outlet
The process is configured with the following phases:
- Load (duration: `load_duration`)
- Wash (duration: `wash_duration`)
- Elute (duration: `gradient_duration`, with gradient)
- Optional final wash (duration: `final_wash_duration`)
"""
def __init__(
self,
column: ChromatographicColumnBase,
c_load: list[float],
c_salt_low: list[float],
c_salt_high: list[float],
flow_rate: float,
load_duration: float,
wash_duration: float,
gradient_duration: float,
final_wash_duration: float = 0.0,
set_initial_conditions: bool = True,
) -> None:
"""
Initialize LWE process.
Parameters
----------
column : ChromatographicColumnBase
Chromatographic column object.
c_load : list[float]
Feed concentration.
c_salt_low : list[float]
Low salt buffer concentration.
c_salt_high : list[float]
High salt buffer concentration.
flow_rate : float
Flow rate.
load_duration : float
Loading duration.
wash_duration : float
Wash duration.
gradient_duration : float
Gradient duration.
final_wash_duration : float, optional
Optional final wash step with high salt buffer. Defaults to 0.0.
set_initial_conditions : bool, optional
Whether to set initial column conditions. Defaults to True.
"""
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_load=c_load,
c_salt_low=c_salt_low,
c_salt_high=c_salt_high,
set_initial_conditions=set_initial_conditions,
)
super().__init__(flow_sheet, 'LWE')
self.cycle_time = (
load_duration
+ wash_duration
+ gradient_duration
+ final_wash_duration
)
gradient_slope = flow_rate / gradient_duration
# Durations
self.add_duration('load_duration', load_duration)
self.add_duration('wash_duration', wash_duration)
self.add_duration('gradient_duration', gradient_duration)
if final_wash_duration > 0:
self.add_duration('final_wash_duration', final_wash_duration)
# Events
# Load
self.add_event('load_on', 'flow_sheet.load.flow_rate', flow_rate, 0)
# Wash
self.add_event('load_off', 'flow_sheet.load.flow_rate', 0.0)
self.add_event_dependency('load_off', ['load_on', 'load_duration'], [1, 1])
self.add_event('wash_on', 'flow_sheet.salt_low.flow_rate', flow_rate)
self.add_event_dependency('wash_on', ['load_off'])
# Elute
self.add_event(
'gradient_salt_low_start',
'flow_sheet.salt_low.flow_rate',
[flow_rate, -gradient_slope],
0,
)
self.add_event_dependency(
'gradient_salt_low_start',
['wash_on', 'wash_duration'],
[1, 1],
)
self.add_event(
'gradient_salt_high_start',
'flow_sheet.salt_high.flow_rate',
[0, gradient_slope],
0,
)
self.add_event_dependency('gradient_salt_high_start', ['gradient_salt_low_start'])
# Final Wash
self.add_event('gradient_salt_low_end', 'flow_sheet.salt_low.flow_rate', 0.0)
self.add_event_dependency(
'gradient_salt_low_end',
['gradient_salt_low_start', 'gradient_duration'],
[1, 1],
)
if final_wash_duration > 0:
self.add_event(
'final_wash_on',
'flow_sheet.salt_high.flow_rate',
flow_rate,
)
self.add_event_dependency('final_wash_on', ['gradient_salt_low_end'])
self.add_event('final_wash_off', 'flow_sheet.salt_high.flow_rate', 0.0)
self.add_event_dependency(
'final_wash_off',
['final_wash_on', 'final_wash_duration'],
[1, 1],
)
def _build_flow_sheet(
self,
column: ChromatographicColumnBase,
c_load: list[float],
c_salt_low: list[float],
c_salt_high: list[float],
set_initial_conditions: bool = True,
) -> FlowSheet:
"""Build and return the flow sheet for LWE process."""
component_system = column.component_system
# Unit Operations
load = Inlet(component_system, name='load')
load.c = c_load
salt_low = Inlet(component_system, name='salt_low')
salt_low.c = c_salt_low
salt_high = Inlet(component_system, name='salt_high')
salt_high.c = c_salt_high
if set_initial_conditions:
column.c = c_salt_low
if "cp" in column.parameters:
column.cp = c_salt_low
outlet = Outlet(component_system, name='outlet')
# Flow Sheet
flow_sheet = FlowSheet(component_system)
flow_sheet.add_unit(load, feed_inlet=True)
flow_sheet.add_unit(salt_low, eluent_inlet=True)
flow_sheet.add_unit(salt_high, eluent_inlet=True)
flow_sheet.add_unit(column)
flow_sheet.add_unit(outlet, product_outlet=True)
flow_sheet.add_connection(load, column)
flow_sheet.add_connection(salt_low, column)
flow_sheet.add_connection(salt_high, column)
flow_sheet.add_connection(column, outlet)
return flow_sheet
