Transport by Belt Conveyor: Oper. Conds Tab

Variable Definitions, Ranges and Default Values

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

Variable	Default Value	Range

○ Ignore Volatile Component Evaporation ? Check or uncheck this box to ignore or consider the evaporation of volatiles, respectively, during belt conveying.	Yes	Yes/No
○ Volatile ? Check the box next to a component to indicate that the corresponding component is volatile.	No	Yes/No
◙ Evaporation % The evaporation percentage of a volatile component.	0.0	0-100
● Initial LOD (%) The amount of volatile components in a sample measured using a Loss On Drying (LOD) test before belt conveying.	0.0	0-100
○ Final LOD (%) The amount of volatile components in a sample measured using a Loss On Drying (LOD) test after belt conveying.	5.0	0-100
○ Ignore Heat Losses ? Check this box to ignore the heat losses to the surroundings during belt conveying. Un-check this box to account for heat losses to the surroundings indirectly, by specifying a smaller exit temperature than the one corresponding to adiabatic operation.	Yes	Yes/No
◙ Exit Temperature (C) The temperature of the bulk solids at the end of belt conveying.	25.0	Positive
○ Specific Loading Rate (Loading Rate/Belt With) ((MT/h)/cm) The mass flowrate of the feed per equipment unit and per belt width.	2.0	Positive
● Operating Loading Rate (per unit) (kg/h) The mass flowrate of the feed stream per equipment unit.	0.0	Positive
○ Setup Time (min) The amount of time (per cycle) spent before each operation is carried in preparation for the actual execution of the operation. It may involve actions like cleaning, vacuuming, setting up of equipment, etc. which the user opted not to model explicitly.	0.0	Positive
◙ Process Time (min) The actual duration of the operation (per cycle).	60.0	Positive
○ Ignore Labor? Check this box to ignore labor for this operation. This option is used only if the process time is set by a master-slave relationship.	Yes	Yes/No

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 Transport by Belt Conveyor: Modeling Calculations.

MT stands for Metric Ton (1,000 kg)

•Volatile Component Evaporation...

To specify volatile component evaporation data, you must first uncheck the “Ignore” box next to “Volatile Component Evaporation”. Then, all volatile components that are evaporated during belt conveying must be identified as such by checking the “Volatile?” box next to their component names. If the evaporation of volatile components is calculated by the program based on Final LOD, then all components that are set as “Volatile” will have the same evaporation percentage. If that is not the case, then, you need to specify user-defined values for the evaporation percentages of all components that are set as “Volatile”.

•Heat Losses...

If the heat losses to the surroundings are ignored (i.e., the “Ignore” box next to “Heat Losses” is checked), the exit temperature will be the same as the feed stream temperature. To account for heat losses, you may uncheck the “Ignore” box next to “Heat Losses” and specify a lower exit temperature than the feed stream temperature (but higher than the ambient temperature that is specified at the flowsheet level).

•Duration Options...

In Rating Mode, you can set the process time (and the setup time), allow the process time to be calculated (based on the loading rate of the units), or allow the duration to match exactly the duration of another operation either in the same procedure or in another procedure. In Design mode, you must either specify the process time (and the setup time) or allow the duration to match exactly the duration of another operation (either in the same procedure or in another procedure).

If you choose to match the duration of this operation with the duration of another operation, you introduce a master-slave relationship between the two operations. The program will match the setup-time, the process time and the turnaround time of this conveying operation (the ‘slave’) with the corresponding times of the reference operation (the ‘master’ operation). For more on master-slave relationship, see The Scheduling Tab.