Singularities of realization of film boiling on wire heaters. Organic liquids

The singularities of realization of the mode of film boiling on wire heaters are investigated in a wide range of organic liquids. Carbon tetrachloride and various alcohols ($\mathrm{C}_1$–$\mathrm{C}_5$) are used for investigation. It is demonstrated that chemical reactions accompanied by gas liberation proceed in the cavity of film boiling, which are caused by the thermal decomposition (pyrolysis) of the original substance. The kinetics of chemical gas liberation are studied, and the composition of reaction products is determined as a function of the heater and liquid temperature and of the heater material. It is demonstrated that the gas liberation in subcooled liquids at high heater temperatures is fully defined by the chemical processes. It is found that, in the case of a short heating element and in liquids subcooled to the saturation temperature, the heat transfer in the film mode occurs in the form of a self-oscillatory process with the oscillation amplitude of the heater temperature of $350$–$400^\circ$C. The mechanism of the emergence of such oscillation is suggested.