Porous mass header
The highly flammable gas acetylene is an endothermic compound which can decompose extremely explosively when in its solid or liquid states or in its gaseous state under pressure. If, in fact, it is compressed to above 1.5 bar and then subjected to a mechanical or thermal shock, this can give rise to decomposition into carbon and hydrogen, which proceeds rapidly and with a great release of energy. For this reason, acetylene cannot be contained and transported in the state of a compressed gas in cylinders; instead, advantage is taken of its high solubility in certain solvents such as acetone and dimethylformamide, to store it in solution in cylinders filled with an inert porous mass: the porous filling mass.
The fine alveolate structure of the mass which is impregnated with solvent in carefully measured quantities, offers an enormous gas-solvent contact surface through which the acetylene is absorbed and released rapidly and in complete safety.
Towards the end of the last century, different substances were used as absorbent materials, such as carbon, kieselguhr, peat, pumice, asbestos and some vegetable fibres such as cellulose waste and kapok, used in a loose state. Later on, in the early years of the twentieth century, different formulations were proposed which included a binder such as lime, cement and others, with the objective of making the absorbent mass more compact and mechanically resistant.