Cooling Crystallizer: 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 Calculate (Design Mode), the user specifies the Maximum Volume and the system computes the Number of Units and the Volume. The variable Max Allowable Working to Vessel Volume is used for sizing the vessel (in Design mode) if no sizing-capable operations are available in the specific procedure. In that case, the procedure selects the max liquid volume present in the vessel during that procedure and divides that number by the ‘Max Allowable Working / Vessel Volume’ to calculate the vessel volume. For more information the sizing of the crystallizer, see Continuous Cooling Crystallization: Modeling Calculations.

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 includes cost of the agitator and 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 an extra cost penalty is applied.

For more information on this equipment, see Cooling Crystallizer.

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