Abstract: The invention provides a process for removal of gaseous decomposition products from high temperature heat transfer fluid HTF of an operational solar thermal power plant having an HTF circuit, in which a volume increase of the HTF in the HTF circuit which is caused by incident solar radiation in an HTF-traversed solar field and consequent heating by day takes place regularly in a day-night cycle and the additional volume formed by the volume increase is collected from the HTF circuit in an expansion vessel, a portion of the additional volume of the HTF is transferred into a drainage vessel operated at relatively low pressure in which gaseous decomposition products and low-boiling constituents escape from the HTF, wherein the low-boiling constituents are condensed, and during the volume contraction of the HTF occurring during the night-time cooling a portion of the additional volume of the HTF is recycled from the drainage vessel into the expansion vessel and from the expansion vessel into the HTF circuit, w

Abstract: The invention provides a process for removal of gaseous decomposition products from high temperature heat transfer fluid HTF of an operational solar thermal power plant having an HTF circuit, in which a volume increase of the HTF in the HTF circuit which is caused by incident solar radiation in an HTF-traversed solar field and consequent heating by day takes place regularly in a day-night cycle and the additional volume formed by the volume increase is collected from the HTF circuit in an expansion vessel, a portion of the additional volume of the HTF is transferred into a drainage vessel operated at relatively low pressure in which gaseous decomposition products and low-boiling constituents escape from the HTF, wherein the low-boiling constituents are condensed, and during the volume contraction of the HTF occurring during the night-time cooling a portion of the additional volume of the HTF is recycled from the drainage vessel into the expansion vessel and from the expansion vessel into the HTF circuit, w

Abstract: A process for preparing organopolysiloxane compositions (A) having a viscosity measured at 25° C. of at least 500 Pa·s., wherein organopolysiloxanes (O) and fillers (F) are mixed and kneaded in a first process stage in a kneading cascade having at least two kneading chambers arranged in series adjacent one another, each containing kneading tools having parallel axes and capable of being driven in co-rotating or counter-rotating directions, the chambers connected to one another by means of openings through which material can pass in a direction transverse to the axes of the kneading tools, with the first kneading chamber having a feed opening and the last kneading chamber having a discharge opening, to give raw mixtures, and the raw mixtures are kneaded and degassed in a reciprocating kneader in a second process stage.

Abstract: A process for preparing organopolysiloxane compositions (A) having a viscosity measured at 25° C. of at least 500 Pa·s., wherein organopolysiloxanes (O) and fillers (F) are mixed and kneaded in a first process stage in a kneading cascade having at least two kneading chambers arranged in series adjacent one another, each containing kneading tools having parallel axes and capable of being driven in co-rotating or counter-rotating directions, the chambers connected to one another by means of openings through which material can pass in a direction transverse to the axes of the kneading tools, with the first kneading chamber having a feed opening and the last kneading chamber having a discharge opening, to give raw mixtures, and the raw mixtures are kneaded and degassed in a reciprocating kneader in a second process stage.

Abstract: The invention relates to a process for the continuous preparation of HTV silicone compositions, which comprises mixing and homogenizing 100 parts by weight of diorgano(poly)siloxane which has a viscosity of 50 to 100,000 Pas at 25.degree. C. with at least 20 parts by weight of finely divided silicon dioxide which has a tamped density of more than 0.01 kg/l in an oscillating single-shaft pilgrim-step kneader.

Abstract: A process for preparing diorganopolysiloxanes having terminal Si-bonded hydroxyl groups which comprises reacting an organosilicon compound selected from a cyclic diorganopolysiloxane, a diorganodichlorosilane hydrolysis product and mixtures thereof with from 0.1 to 3 percent by weight of a diorganodichlorosilane, based on the weight of the organosilicon compound, i.e., the cyclic diorganopolysiloxane and/or diorganodichlorosilane hydrolysis product employed, in the presence of from 1 to 50 ppm by weight of phosphonitrile chloride, based on the total weight of the organosilicon compound and diorganodichlorosilane employed, to form diorganopolysiloxanes containing an Si-bonded chlorine atom in each of the terminal units, then treating the reaction mixture with water or an aqueous solution, separating off the aqueous phase from the diorganopolysiloxanes containing an Si-bonded hydroxyl group in each of the terminal units and thereafter removing the low boiling constituents by distillation.

Abstract: A process for producing room temperature-vulcanizable silicone compositions which comprises mixing, in a first step, crosslinkable diorgano(poly)siloxanes, filler(s) and either catalyst(s) or crosslinking agent(s) and a part or all of the optional additives to be used in a continuusly operating closed mixer, and in a second step, metering the crosslinking agents and/or catalyst(s) not added in the first step and the remainder of the optional additivies to be used into the mixture thus obtained in an oscillating pilgrim-step kneader where the mixture is homogenized and degassed.