Both the theoretical and experimental studies on boiling heat transfer were carried out in a vapor -liquid -solid three phase vertical fludized bed. The boiling heat transfer characteristics for the three-phase fludized bed were investigated. A calculation method on theboiling heat transfer coefficients was proposed. The experimental results showed that the boiling heat transfer was enhanced due to the presence of the solid particles

that the boiling heat transfer coefficient of the three-phase fludized bed was about 2 times that of the vapor - liquid two -phase flow

and that the stability of the boiling process in the three-phase fludized bed was better than that in the vapor-liquid two-phase flow.