Experimental study on flowing burning behaviors of a pool fire with dripping of melted thermoplastics

•A new experimental setup was developed to generate hot thermoplastic liquids.•Flowing of pool fire was studied in a T-trough with dripping hot thermoplastic liquids.•The flame spread velocities of PS pool fire in the T-trough are smaller than PP and PE.•The mass burning rate of the PS pool fire in T-trough are relatively large.•The fire hazard of PE and PP is higher than PS for their fast flowing burning. The objective of this work is to quantitatively investigate the dripping-burning and flowing fire of thermoplastics. A new experimental setup is developed with a heating vessel and a T-trough. Hot thermoplastic liquids are generated in the vessel by electric heating. N2 gas is continuously injected into the vessel to avoid a sudden ignition of fuel in it. The detailed flowing burning behaviors of pool fire in the T-trough are analyzed through the measurements of the mass, heat flux and temperatures etc. The experimental results suggest that a continuous dripping of melted thermoplastic liquids in a nearly constant mass rate can be successfully made in the new setup. It also shows that the mass dripping rate of melted PS liquid is smaller than PP and PE since its large viscosity. In addition, the flame spread velocities of hot liquids of PS in the T-trough are also smaller than that of PP and PE because of its large viscosity. The mass burning rate of the PP and PE pool fire in T-trough are smaller than PS. Finally, considering the heating, melting, dripping and flowing burning behaviors of these polymers, it is suggested that the fire hazard of PE and PP are obviously higher than PS for their faster flowing burning.