Adiabatic oxidatively-heating test

The above approach, i.e., the heat generation data by the adiabatic self-heating test, or by the adiabatic oxidatively-heating test, and, the heat transfer data by experimental measurements, has been adopted throughout a series of studies described herein in order to calculate the 7 for a chemical of the TD type, including every gas-permeable oxidatively-heating substance, having an arbitrary shape and an arbitrary size, placed in the atmosphere under isothermal conditions. 

For the standard temperature in the adiabatic oxidatively-heating test, refer to (2) of Subsection 8.3.1. 

The structure of the adiabatic jacket is shown in Fig. 74 in Section 7.2, in particular, in connection with the performance of the adiabatic oxidatively-heating test. 

Once the temperature of the chemical in the cell reaehes a temperature preset on the two-pen strip chart recorder, the limit switch works in order that the main power supply to the adiabatic self-heating process recorder may be cut automatically. However, It has been made an established rule in the two kinds of adiabatic tests, which are started each from a T performed for 2 cm of a chemical of the TD type, including every gas-permeable oxidatively-heating substance, to interrupt each test, as soon as the temperature of the chemical in the cell increases by the definite value of AT of. 25 K from the T, in the adiabatic self-heating test, or from the corresponding standard temperature in the adiabatic oxidatively-heating test. Some reasons why a value of AToi. 25 K was chosen as the definite value of AT m the two kinds of adiabatic tests are explained in the following subsection. 

Chapter 7 Procedure to perform the adiabatic oxidatively-heating test in order to calculate ultimately the heat generation data of a gas-permeable oxidatively-heating substance... 

That is, for the purpose of calculating the 7). for a heap of a gas-permeable oxidatively-heating substance, having some one of the several specific shapes above referred to as well as an arbitrary value of r, placed in the atmosphere under isothermal conditions, we have only to perform, on the one hand, several adiabatic oxidatively-heating tests, which are started from each T, with mutual intervals of 1 2 K, in order to calculate the heat generation data of the... 

As commented at the beginning of Section 7.4, however, there exist as a matter of fact four kinds of gas-permeable oxidatively-heating substances. It thus follows that there are four kinds of adiabatic oxidatively-heating tests in all, or rather four kinds of testing procedures, in all, corresponding each to the four kinds of gas-permeable oxidatively-heating substances. The four kinds of testing procedures are explained in detail in Section 7.4, respectively. 

Procedure to perform the adiabatic oxidatively-heating test... 

The draft cell and the touch-flow cell, in the four kinds of cells, are used exclusively in the adiabatic oxidatively-heating test. In this regard, the open-cup cell, one of the three kinds of open cells, is used only in the adiabatic selfheating test performed for a non-volatile liquid chemical, or powdery chemical, of the TD type at atmospheric pressure. 

Incidentally, as commented at the beginning of Subsection 4.5.2, and as explained in Subsections 7.4.1, 7.4.2 and 7.4.3, it is not required, in principle, to determine the T, of each run by inserting the reference cell assembly into the adiabatic jacket in the adiabatic self-heating process recorder, prior to the insertion of the sample cell assembly into the jacket, in the adiabatic oxidatively-heating test performed by means of the cell assembly including either of the two kinds of open cells, i.e., the draft cell or the touch-flow cell, although it is indispensable to do so in the adiabatic oxidatively-heating test... 

Figure 80. About 2 cm of silica of comparatively coarse particles is charged in an open-cup cell, i.e., the cell with which the reference cell is prepared. Silica of comparatively coarse particles is used as the reference material in the adiabatic oxidatively-heating test. In this photograph, however, the cell is filled with milk in place of silica of coarse particles for the convcnicnec of photography.

Figure 83. After having lowered again the laboratory jaek a little, a fairly small vibrator is applied to the base of the opcn-cup cell in order that siliea of eoarsc particles eharged in the cell may come closely in contact with the glass capillary tube. The reference cell assembly is now ready for the adiabatic oxidatively-heating test.

In this connection, the whole procedure to perform the adiabatic oxidatively-heating test for a moisture-containing gas-permeable oxidatively-heating substance is explained in detail in Subsection 8.4.1 by taking the procedure performed for 0.3 g of the sawdust of Port Orford cedar charged in the draft cell, into which air is supplied, as an example. 

After the drying time above referred to has passed, the temperature of the air bath is reset at a proper value, i.e., the nominal T, of the run, by means of the temperature dial on the air bath on the basis of the oxidatively-heating property of the substance tested to give estimated rates of increase in temperature of 1.25 BC/h in the adiabatic oxidatively-heating test. 

On the other hand, however, the oxidatively-heating process, in the early stages, of 2 cm of the substance charged in the draft cell and subjected to the adiabatic oxidatively-heating test is recorded, as an analog signal as well, with the T pen on the strip chart of the two-pen strip chart recorder to look about the process as a whole. 

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