Material Flow

“Material Flow” or Advection

Thermal Desktop® is very capable of modeling steady and unsteady heat transfer problems including conduction, convection, thermal radiation, etc. for moving and stationary parts.

When a batch process is to be simulated, or when discrete parts move (such as ingots through a furnace, or ground-tracking antennae on satellites), the part itself can be translated or rotated within a transient solution. But when the motion is continuous, such that a steady-state solution is possible, different modeling methods are available and should be employed.

Examples of such continuous motion include a sheet of glass solidifying as it is lowered through a temperature-controlled zone, a gypsum board moving through a drier, and a conveyor belt carrying baked goods through a continuous oven. In those circumstances, a fixed model of the both stationary parts (heat lamps, ovens, driers, etc.) and the moving parts (rollers, sheets, belts, etc.) is built. Then, an advection or “material flow” term is superimposed on the rotating or translating parts.

For example, below is an open mesh conveyor belt with rollers moving under a heat lamp (more like a laser: collimated). Ray plots have been superimposed to show the lamp rays passing through the mesh belt.

Conveyor with radiation and advection

Example applications for this capability include:

  • Belt conveyor furnaces, conveyor ovens
  • Steel and aluminum sheet metal manufacturing
  • Glass making (especially plate glass)
  • Paper making, fiber products, particle board and flakeboard drying and curing, drywall (wallboard) manufacturing
  • Optical fiber manufacturing (drawing fiber optic cable through a furnace)
  • Pebble bed reactors
  • Coke furnaces
  • Rotary furnaces
  • Carbon foam and metal foam heat exchangers, geothermal storage systems
  • Rotating disk heat exchangers and dehumidifiers
  • Moving belt heat exchangers, moving belt radiators

Hot Wire: Material Flow Example

A large rectangular copper “wire” passes through a continuous-flow tubular furnace used to harden a thermoset polymer coating. A pair of cooled rollers at the exit of the furnace help to both position the wire and smooth the coating.

Bar through oven

Advection model results

Advection model results roller detail

Advection model coating temperatures