Takashi Kotoyori
As the author of the book Critical Temperatures . . . of Chemicals, I would like to inform all the readers of the following two points.
1. The basic concept of the thermal explosion theory is that whether the thermal explosion or the spontaneous ignition of a chemical of the TD type, including every gas-permeable oxidatively-heating substance, occurs or not is decided on the balance between the rate of heat generation in the chemical and the rate of heat transfer from the chemical to the atmosphere in the early stages of the self-heating process.
Accordingly, representations, such as “the balance at the critical state for the thermal explosion which exists at the end of the early stages of the self-heating process”, are incorrect and misleading. Such clauses or phrases should thus be deleted.
2. When confined in the closed cell and subjected to the isothermal storage test performed at a temperature, Tt, which is situated below the melting point of the chemical concerned, a sample of a powdery chemical of the quasi-AC type warms slowly up to the Tt, because a phase transition, endothermic fusion, of the chemical proceeds very slowly all through this time. Once, however, the extent of melting of the chemical attains to a definite threshold value in the course of time, an exothermic quasi-autocatalytic reaction of the resultant liquefied chemical starts violently.
Accordingly, representations, such as “the time from the insertion of a cell into the isothermal storage testing device till the start of the quasi-autocatalytic reaction occurring simultaneously with the finish of melting of the chemical”, are incorrect and misleading. Such clauses or phases should thus be deleted.
At all events, in order to calculate the SADT for a powdery chemical of the quasi-AC type, all we have to do is to measure the time from the insertion of the cell into the isothermal storage testing device till the start of the quasi-autocatalytic reaction of the sample at each Tt in the isothermal storage test.