FORCED IGNITION AND FLAME SPREAD TEST (FIST)

Lift Apparatus
- The LIFT (ASTM E 1321-93) is currently used to obtain the flammability diagrams of solid combustible materials. 

The LIFT apparatus induces a buoyant flow which becomes the source of convective heat and mass transfer.
There is experimental evidence that the generalization of results obtained in buoyant conditions to conditions where forced convection is dominant (micro-gravity conditions in space-based vessels and facilities) is questionable.

Flammability Diagram of PMMA from LIFT

•Two Tests:

Piloted Ignition under external radiant flux

Flame Spread under external radiant flux

 

Provides Material Flammability Properties

Ignition Delay Time (tig)

Critical External Flux for Ignition (q”o,ig)

Ignition Temperature (Tig)

Flame Spread Rate (Vf)

Limitation:

Relies on gravity for transport of heat and mass

Simplified theoretical background

·By plotting ignition and flame spread data in a flammability diagram the critical heat flux for ignition can be extracted. Fitting the the theoretical formulas to the data for ignition and flame spread, the fire properties are obtained.