Abstract
In order to establish the plastic injection technology in the blast furnace, the behaviors of plastic pyrolysis, combustion and gasification reaction have been investigated with two kinds of model experiment; one is the vertical tower type reactor called the combustion model and the other is the blast furnace type reactor called the hot model.
The combustion of plastic does not occur in the blast having the temperature of 1250°C and the O2 enrichment of 0% in the blowpipe and tuyere. The combustion starts in the air over the temperature of 1550°C, but the CO2 gasification does not occur at this temperature in the combustion model.
The split of plastic occurrs in the atmosphere over the temperature of 2000°C in the raceway from 10002000μm to 200μm. The split plastic is burnt in the raceway, the unburnt plastic is consumed and accumulated in the hot model and it does not flow out of the top.
The entering of plastic contained fines into the deadman can be suppressed by injecting the plastic directly into the raceway through the tuyere or by keeping the distance of the lance tip from the tuyere nose as short as possible in case of the injection through the side of blowpipe.
The plastic injection alone is better than the mixing injection with pulverized coal in order to maintain the permeability in the lower part of the hot model.
