Abstract: The invention relates to the cocurrent gasification of coal and to a gas generator. The gas generator (11) comprises a vertical sealed vessel, the lower third of which is divided into several identical vertical compartments (12). Coal is loaded at the top (17). The major part of the hot reactive gas under pressure is introduced at the top (18), and the remaining part at lower levels (21, 22). Gas evacuation (24) is stopped from one compartment (12) in turn, gas produced is blown in order to unclog the filters (25, 26) and to loosen the ash, the ash is extracted at the bottom (23) and cold reactive gas is blown countercurrently in order to complete the combustion and to cool the ash. This gas generator enables coal from any source to be used and does not require purification downstream.

Abstract: A method for maintaining constant the composition of liquefied gas in a store (1) comprises extracting product in its gas phase from the store by means of a compressor (8) to raise its pressure. The gas is then cooled in a first heat exchanger (9) and then in a second heat exchanger (10), to a final temperature such that on expanding the gas into a tank (11) most of it is liquefied. The small amount of remaining gas is recycled to the compressor inlet after passing through the first heat exchange as its cooling fluid. The product is also extracted in its liquid phase (3) by a pump (19). The liquid is then passed through a battery of pumps (20) which raise it to a pressure high enough for a distribution network to be directly supplied therewith (after vaporization). A portion of the highly compressed liquid phase is used as the cooling fluid for the second heat exchanger (10).

Abstract: The walls of the cavity (10) are interconnected by rounded portions. The cavity (10) may be cylindrical in shape with hemispherical ends (11, 12). This shape reduces cracking in the walls during an initial cavity cooling process.

Abstract: To block the mouth of a well (1) opening out in the ceiling of an underground cavity (2), a part (4) in the shape of a keystone is used, which has a hole through the middle for the passage of pipes (31, 32), suitable cements are then poured in to make the whole system integral, and the well is filled.