Abstract: A novel work-step attachment for an extension ladder is described. The work-step attachment generally comprises a platform which is secured to a ladder segment having two vertical side frames in parallel relationship and at least one horizontal rung extending therebetween. The work-step attachment also comprises a hooking element adapted to engage a rung of an extension ladder, as well as a locking element to lock the platform in a first position in which it is aligned with the rung of the ladder segment and in a second position in which it is substantially aligned in the plane of the parallel side frames of the ladder segment.

Abstract: A cyclone separator or hydrocyclone with good separation efficiency and large capacity comprises a substantially cylindrical or slightly conical hollow body (1), the lower part of which terminates in an outlet opening (6) for liquid enriched with respect to solid particles, and in which the outlet (7) for purified liquid is defined between a centrally arranged body (11) and a guiding tube (2), and in which the liquid to be purified is introduced via a particularly designed nozzle (13).

Abstract: A cryogenic process for removing acid gases from natural or synthesis gases, comprising the following stages:(a) feeding the natural or synthesis gas to a first absorption column in order to absorb the H.sub.2 S;(b) cooling the substantially H.sub.2 S-free gas to condense part of the CO.sub.2 contained in said gas;(c) feeding the cooled and partly condensed gas to a second absorption column in order to reduce the CO.sub.2 content to the required value;(d) regenerating the solvent or solvents used in the acid gas absorption, the solvent or solvents used being chosen from esters, alcohols or ethers, of low molecular weight.

Abstract: A process for recovering power is disclosed, by which excess electric power is exploited for electrolyzing alkali metal hydroxides (molten) and the thusly obtained pure alkali metals are stored. When the demand of electric power becomes critical, the alkali metals are reconverted into their hydroxides and the reaction heat, along with the hydrogen produced in the reaction, is recovered to produce steam: the latter can be used either to produce electricity, or to use its heat, or both.

Abstract: A thermally driven multi-effect distillation process and apparatus are disclosed in which liquid is introduced into a plurality of evaporating and condensing stages or chambers while heat energy is passed through the stages or chambers in a direction countercurrent to the direction of flow of the liquid which undergoes evaporation to form condensate and distilland in each stage or chamber while transferring the heat of condensation to the next downstream stage or chamber and maintaining a minimum temperature differential between stages or chambers, and separately removing condensate and distilland from each stage or chamber while rotating the stages or chambers about an axis passing through the points of introduction thereto of the liquid and heat energy.Generally the apparatus comprises a plurality of adjacent evaporation and condensation chambers and means for introducing liquid and heat energy thereto in countercurrent directions.