Aerobic Bio-Oxidation Operations: Oper. Conds Tab

Variable Definitions, Ranges and Default Values

The following table shows a brief description of the variables appearing in this tab. The table also displays their default values and their generally acceptable range:

Variable	Default Value	Range

◙ Final Temperature (^oC) The final temperature of vessel contents after the end of the operation.	25.0	Positive
◙ Heating Duty (kcal/h) The heat transfer rate of the heating agent, if a heating agent is used.	0.0	Positive
◙ Cooling Duty (kcal/h) The heat transfer rate of the cooling agent, if a cooling agent is used.	0.0	Positive
○ Heat Transfer Agent Name Indicates the heat transfer agent used for the operation. Click on the list box to bring up a list of available heat transfer agents in order to select one.	<Steam>	Any Heat Transfer Agent
● Inlet Temp. (^oC) The inlet temperature of the heat transfer agent.	152.0	Positive
● Outlet Temp. (^oC) The outlet temperature of the heat transfer agent.	152.0	Positive
● Rate (kg/h) The mass flow rate of the heat transfer agent.	0.0	Positive
○ Heat Transfer Efficiency(%) The heat transfer agent efficiency. If the value is lower than 100% then an increased heat transfer agent amount will be calculated by the program to satisfy the required duty.	100.0	[0,100)
○ Pressure Set by User Check this box to set the pressure.	No	Yes/No
◙ Pressure (atm) The operating pressure of the vessel.	1.0	Positive
○ Aeration Inlet Stream Indicates the input port that is connected to the aeration stream. If an input stream is already present at the selected port, then the button next to the selection is active. Click on the button to bring up the attached stream’s simulation dialog in order to provide the composition of the material being charged.	<None>	Any Input Port
○ Dissolved Oxygen Conc. (g/L)	0.0	Positive
○ Air Requirement Set by User Check this box to set the air requirement.	Yes	Yes/No
◙ Air Requirement (m³ Air per m³ Liq/min) The air requirement expressed as volume of air required per unit volumetric flow rate of liquid.	0.030	Positive
○ Power Type Indicates the power type that is used by the operation. Click on the list box to bring up a list of available power types in order to select one.	<Std Power>	Any Power Type
◙ Specific Power (Per Volume) (kW/m³) The power consumed for agitation per volume of material.	0.04	Positive
◙ Total Power (kW) The total power consumed for agitation (per cycle).	0.0	Positive
◙ Power Per Unit (kW) The power consumed for agitation per equipment unit.	0.0	Positive
○ Sludge Wasting Stream One Indicates the output port that is connected to the first sludge wasting stream. Click on the list box to bring up a list of available output ports in order to select one.	<None>	Any Output Port
○ Sludge Wasting Stream Two Indicates the output port that is connected to the second sludge wasting stream. Click on the list box to bring up a list of available output ports in order to select one.	<None>	Any Output Port
● Sludge Residence Time (h)	0.0	Positive

Symbol Key: ○ User-specified value (always input); ● Calculated value (always output); ◙ Sometimes input, sometimes output

Specification Choices / Comments

The following list describes the available specification choices in this tab; for more details on how these are implemented, see WM Stoichiometric Aerobic Bio-Oxidation: Modeling Calculations.

•Aeration Options...

You may select between Surface and Diffusion Aeration. For diffused aeration, you may set the air requirement (in m³ air/ m³ liq-min) and that in turn is used to adjust the flowrate of the aeration stream.

•Sludge Data...

The Sludge Wasting Streams are the stream in the activated sludge loop through which the sludge is removed from the loop. These are typically the effluent stream and the stream that leads to the sludge treatment section. The flow of sludge in the sludge-wasting stream(s) is used to calculate the average sludge residence time in the activated sludge loop.