Working with the Process Schedule

Materials and heat can be added at any time in any amount. They can be either added to a:

bulk zone (such as steel, slag, etc.), or
reaction zone (interface between two bulk zones).

These types of materials are used in the process schedule set up:

Material addition (in tonne, kilogram, etc.)
Continuous material addition (in kilogram per minute, etc.)
Thermal / electrical power (i.e. a continuous heat addition in MW)

A material addition is typically used to model some event like emptying a bucket into the melt. A continuous material addition is instead used to model a continuous material feeding into the melt, such as wire feeding. Finally, heat can be added or removed during a time step and this is defined as power.

Generally the addition of materials and heat is modeled in the process simulations for any time point tn as follows:

Material additions happen immediately after the previous time point tn-1, i.e. at the beginning of the time step.
Continuous material and heat additions (power) are conceptually happening during the complete time step between tn-1 and tn.

The data presented in the results is always referring to the time point, i.e. to the end of the time step. This means that reactions and heat transfer have happened between adding materials and heat at the beginning of the time step and the end of the time step. If for example a strongly cooling material is added, a possibly quite large heating of the zone might have happened until the end of the time step.

The first two time points are different:

The first time point t₀ at t=0 does not represent a time step, instead only a mixing and equilibrium reaction of the material additions in each bulk zone is taking place. There are no reaction zones existing at this time point.
The second time point t₁ represents the first time step in the simulation where the different bulk zones react between each other via the reaction zones. Nevertheless it is conceptually identical to any other time point.