Abstract: A directional valve includes a fixing lug (13), which is arranged eccentrically to a valve membrane (16) and is arranged at a valve housing (15). The dimensions of the fixing lug (13) are selected for fixing the valve membrane (16) relative to the sealing surface (2) of valve seat (1). The size of the eccentric offset (x) is in a range between 8% and 15% of the axis length (D) of the greatest longitudinal extension of valve membrane (16).

Abstract: A directional valve for a respirator product includes a valve housing (15) and a valve seat (1) for receiving a flexible valve membrane (16). The valve seat has a circular and essentially flat sealing surface (2) surrounding an opening (3), which is sealingly covered by the valve membrane during an inspiration phase. A fixing lug (13), on the valve housing (15), fixes the valve membrane in the valve seat and is arranged offset in relation to the center of the valve membrane, such that an entire circumferential surface of the valve membrane is lifted off from the sealing surface during an expiration phase. The fixing lug is directed essentially at right angles to a flow plane formed by the opening. A counter-support (25), within the opening, is arranged opposite the fixing lug such that the valve membrane is mounted with fixed clamping action, between the fixing lug and the counter-support.

Abstract: The present invention relates to a continuous process for producing lower dialkyl carbonates as a main product and alkylene glycol as a by-product by transesterification of a cyclic alkylene carbonate (e.g. ethylene or propylene carbonate) with lower alkyl alcohols in the presence of a catalyst and also the necessary purification of the dialkyl carbonate in a subsequent process step. For optimization of the economic efficiency and energy efficiency of the process, additional devices are used for intermediate heating of the internal liquid streams within the apparatus.

Abstract: The present invention relates to a continuous process for producing lower dialkyl carbonates as a main product and alkylene glycol as a by-product by transesterification of a cyclic alkylene carbonate (e.g. ethylene or propylene carbonate) with lower alkyl alcohols in the presence of a catalyst and also the necessary purification of the dialkyl carbonate in a subsequent process step. For optimization of the economic efficiency and energy efficiency of the process, additional devices are used for intermediate heating of the internal liquid streams within the apparatus.

Abstract: A directional valve for a respirator product includes a valve housing (15) and a valve seat (1) for receiving a flexible valve membrane (16). The valve seat has a circular and essentially flat sealing surface (2) surrounding an opening (3), which is sealingly covered by the valve membrane during an inspiration phase. A fixing lug (13), on the valve housing (15), fixes the valve membrane in the valve seat and is arranged offset in relation to the center of the valve membrane, such that an entire circumferential surface of the valve membrane is lifted off from the sealing surface during an expiration phase. The fixing lug is directed essentially at right angles to a flow plane formed by the opening. A counter-support (25), within the opening, is arranged opposite the fixing lug such that the valve membrane is mounted with fixed clamping action, between the fixing lug and the counter-support.

Abstract: The present invention relates to a continuous process for preparing lower dialkyl carbonates as main product and alkylene glycol as by-product by transesterification of a cyclic alkylene carbonate (e.g. ethylene carbonate or propylene carbonate) with lower alkyl alcohols in the presence of a catalyst and also the required purification of the dialkyl carbonate in a subsequent process step. To optimize the economics and energy efficiency of the process, additional devices are used for intermediate heating of the liquid streams in the apparatus.

Abstract: A directional valve includes a fixing lug (13), which is arranged eccentrically to a valve membrane (16) and is arranged at a valve housing (15). The dimensions of the fixing lug (13) are selected for fixing the valve membrane (16) relative to the sealing surface (2) of valve seat (1). The size of the eccentric offset (x) is in a range between 8% and 15% of the axis length (D) of the greatest longitudinal extension of valve membrane (16).

Abstract: The present invention relates to a continuous process for preparing lower dialkyl carbonates as main product and alkylene glycol as by-product by catalyzed transesterification of a cyclic alkylene carbonate (e.g. ethylene carbonate or propylene carbonate) with lower alcohols, where the reaction of the alkylene carbonate is carried out with an alcohol containing dialkyl carbonate in countercurrent, characterized in that introduction of a stream containing at least 99.5% by weight of alcohol takes place below the point of introduction for the alcohol containing dialkyl carbonate in a particular spacing ratio between the abovementioned points of introduction.

Abstract: The present invention relates to a process comprising purifying dialkyl carbonates of the formula (II) in one or more columns in the presence of an alkylene oxide of the formula (V) and of an alkyl alcohol of the formula (IV) wherein R1 and R2 represent, independently of one another, linear or branched, substituted or unsubstituted C1-C6-alkyl, R3 and R4 represent, independently of one another, hydrogen, substituted or unsubstituted C1-C4-alkyl, substituted or unsubstituted C2-C4-alkenyl or substituted or unsubstituted C6-C12-aryl, and R5 represents a straight-chain or branched C1-C4-alkyl; and wherein the mean residence time of the dialkyl carbonate in the column(s) is from 0.3 h to 3 h.

Abstract: The present invention relates to a continuous process for purifying a dialkyl carbonate/alkyl alcohol mixture in the preparation of dialkyl carbonate by catalysed transesterification of a cyclic alkylene carbonate (e.g. ethylene carbonate or propylene carbonate) with alkyl alcohols. For the increase in the product quality of the dialkyl carbonate, the selection of the operating parameters of the dialkyl carbonate purification column are crucial, in order to reduce the formation of unwanted by-products such as alkoxy alcohols and aliphatic carbonate ethers.

Abstract: The present invention relates to a continuous process for preparing lower dialkyl carbonates as main product and alkylene glycol as by-product by transesterification of a cyclic alkylene carbonate (e.g. ethylene carbonate or propylene carbonate) with lower alkyl alcohols in the presence of a catalyst and also the required purification of the dialkyl carbonate in a subsequent process step. To optimize the economics and energy efficiency of the process, additional devices are used for intermediate heating of the liquid streams in the apparatus.

Abstract: The present invention relates to a special process for purifying dialkyl carbonates. In particular, the present invention relates to a continuous process for purifying a dialkyl carbonate/alcohol-mixture in the preparation of lower dialkyl carbonate by catalysed transesterification of a cyclic alkylene carbonate (e.g. ethylene carbonate or propylene carbonate) with lower alcohols. To optimize the economics and energy efficiency of the process, an apparatus for intermediate heating of the internal liquid stream is used.

Abstract: The present invention relates to a continuous process for preparing lower dialkyl carbonates as main product and alkylene glycol as by-product by catalyzed transesterification of a cyclic alkylene carbonate (e.g. ethylene carbonate or propylene carbonate) with lower alcohols, where the reaction of the alkylene carbonate is carried out with an alcohol containing dialkyl carbonate in countercurrent, characterized in that introduction of a stream containing at least 99.5% by weight of alcohol takes place below the point of introduction for the alcohol containing dialkyl carbonate in a particular spacing ratio between the abovementioned points of introduction.