Abstract: A motor vehicle headlamp glass washing apparatus comprises a jet nozzle mounted on a retractable jet carrier and supplied selectively from a source of washing liquid under pressure. The jet carrier comprises a variable volume chamber, which is defined by a fixed element and a movable element which slides on the fixed element and which carries the jet nozzle. A spring acts between the fixed and movable elements to bias the movable element into a retracted position. Supply of liquid under pressure to the variable volume chamber initially moves the movable element against the action of the spring into a deployed position, and then supplies the liquid to the jet nozzle.The fixed element is a tube open at a free end and connected to the liquid source at its other end, the movable element comprising a closed body having an internal space communicating with the jet nozzle.

Abstract: Concentrated phosphoric acid and calcium sulfate hemihydrate are directly produced by sulfuric acid attack upon calcium phosphate, the improvements comprising (i) continuously conducting the acid attack reaction, with concomitant formation of crystalline calcium sulfate hemihydrate, in but a single, homogeneous liquid reaction medium comprising the products of reaction, (ii) maintaining constant the temperature of the reaction medium as to effect formation of hemihydrated calcium sulfate, (iii) controlling the amount of reactants introduced to the reaction medium such as to maintain essentially constant, in liquid phase, a determined sulfate ion content, said content being at least 5 g/l and said determined content increasing with decreasing concentrations of P.sub.2 O.sub.5 at a given temperature, and (iv) withdrawing a fraction of reaction effluent, including the concentrated phosphoric acid, and individually separating and recovering hemihydrated calcium sulfate from said reaction effluent fraction.

Abstract: Phosphoric acid is produced by a wet process in a homogeneous medium from calcium phosphate ore, sulphuric acid and a continuously added aqueous solution of recycled acid.Part of the phosphate is treated in a primary reaction medium, prepared separately and differing in composition from the final medium sought. By regulating the compositions of the various reaction media, the present process advantageously increases the concentration of the phosphoric acid produced and/or enhances the quality of filtration, along with other advantages.The process can advantageously be applied for the economic treatment of low-grade, poorly reactive or unground phosphates.