Batch Distillation Vessel: Equipment Tab

Variable Definitions, Ranges and Default Values

The following table shows the meaning of the variables appearing in this tab, as well as their default values and their generally acceptable range. Note that due to the manner by which the variables are used by the sizing and costing equations, the range of acceptable values may be further reduced.

Variable	Default Value	Range

◙ Volume The total vessel volume.	0.0 L	Positive
◙ Max Volume The maximum volume that a unit of this type is available for purchase in the market.	40,000 L	Positive
○ Max Allowable Working/Vessel Volume The maximum ratio of working (liquid) volume of material to total vessel volume allowed.	90%	(0,100]
● Height The internal height of the vessel.	0 m	Positive
● Diameter The internal diameter (or diameter equivalent) of the vessel.	0 m	Positive
○ Height/Diameter The ratio of height to diameter (aka aspect ratio) of the vessel.	2.5	Positive
○ Design Pressure The maximum pressure that the vessel has been designed to withstand.	1.52 bar	Positive
○ Is ASME Vessel? ASME standards of vessel construction will increase the cost of the vessel.	Yes	Yes/No
○ Fractionation Column Attached? A fractionation column attachment is assumed.	No	Yes/No
◙ Number of Trays If the a fractionation column is assumed to be attached, this variables specifies the number of trays in the column.	5	Positive Integer

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

Sizing: Design Mode

In design mode, the liquid volume demand is specified by the operations carried out as part of the (one or more) unit procedures hosted by the equipment resource. Typically, even during the span of a single procedure, more than one operations may demand different volumes. The software will size the vessel based on the largest demand on liquid volume amongst all operations executed in the vessel. Once the largest liquid volume is determined, it is divided by the maximum working-to-vessel ratio in order to determine the actual volume required to carry out the most demanding of the operations. If that volume exceeds the maximum volume specification then the software will assume multiple number of identical units (each with volume equally distributed). From the total vessel volume (per unit) and the aspect ratio (R/D) the actual dimensions of each vessel (diameter and height) are calculated. For more information on sizing a batch distillation vessel, see Batch Distillation.

Sizing: Rating Mode

In User-Defined (Rating Mode), the user specifies the Number of Units and the Volume.

Costing

The equipment purchase cost is based on the total vessel volume. It is supplied by the built-in model assuming as material of construction SS316. Other factors that affect the cost are:

● Conforming to ASME Specification; if checked, then the vessel is assumed to have been constructed according to standards published by the American Society of Mechanical Engineers (ASME) and it is assumed to withstand pressure up to 35psig. Checking this option penalizes the cost by about 20% over the base cost.

● Design Pressure; vessels required to withstand pressures above 3 atm are penalized by about 80% over base cost.

● Fractionation Column / Number of Trays; if a fractionation column is assumed to be attached to the vessel for distilling off and fractionating volatile components, an extra cost penalty is applied.

For more information on this equipment, see Batch Distillation Vessel.

For information on the left-hand side variables and options, see Equipment Data Dialog: Equipment tab.