Abstract: A method for highly concentrating aqueous solutions containing thermally sensitive organic constituents and with or without mineral constituents, wherein firstly, a major portion of the water is extracted by membrane filtration from the solution for pre-concentration and is discharged from the process and the solution which is pre-concentrated is then subjected to a freeze concentration procedure, in which, in the form of separated ice crystallisate, further water is extracted from the solution. To promote results, that concentration may be effected in the freeze concentration procedure until a viscosity of the mother solution of at least 0.0002 m2/s is achieved, and in that the separated ice crystallisate from the freeze concentration with the mother solution adhering thereto as a suspension is returned to the membrane filtration upstream of the membrane filtration or after melting of the ice crystallisate.

Abstract: The invention relates to compounds, comprising at least one donor group and at least one acceptor group, in which the transition energy of the lowest excited triplet hack into the ground state both of the corresponding donor molecule and of the corresponding acceptor molecule being at least 2.2 eV, and the use thereof as an emitter or a carrier material in an optoelectronic component.

Abstract: A resistance welding apparatus includes a welding tool with a welding electrode configured to contact a component. A welding transformer is configured to feed an electric current to the welding tool and a control device is configured to control a polarity of welding transformer by transmitting polarity information to the welding transformer such that a polarity of the welding transformer is switchable. A circuit including two transistors is operably connected in series between the welding tool and an output of the welding transformer and a polarity one of the transistors is rotated relative to the other transistor, such that a polarity of a welding voltage at the welding electrode is switchable with the switching of the polarity of the welding transformer, and such that a polarity of a welding current at the welding transformer is switchable with the switching of the polarity of the welding transformer.

Abstract: The disclosure relates to a power component for providing an electric current, having plates aligned parallel to one another which are connected to the current inputs and the current outputs of power semiconductors embedded in a component carrier. High currents, for example for resistance welding, can thereby be controlled without excessive heat losses resulting in an increase in temperature of the entire arrangement and thereby in a reduction of the service life.

Abstract: A method for highly concentrating aqueous solutions containing thermally sensitive organic constituents and with or without mineral constituents, wherein firstly, a major portion of the water is extracted by membrane filtration from the solution for pre-concentration and is discharged from the process and the solution which is pre-concentrated is then subjected to a freeze concentration procedure, in which, in the form of separated ice crystallisate, further water is extracted from the solution. To promote results, that concentration may be effected in the freeze concentration procedure until a viscosity of the mother solution of at least 0.0002 m2/s is achieved, and in that the separated ice crystallisate from the freeze concentration with the mother solution adhering thereto as a suspension is returned to the membrane filtration upstream of the membrane filtration or after melting of the ice crystallisate.

Abstract: The present invention relates to compounds of the formula (I) where C, D, A, m and n are as defined herein, and to their use in optoelectronic components and to optoelectronic components comprising them.

Abstract: The disclosure relates to a power component for providing an electric current, having plates aligned parallel to one another which are connected to the current inputs and the current outputs of power semiconductors embedded in a component carrier. High currents, for example for resistance welding, can thereby be controlled without excessive heat losses resulting in an increase in temperature of the entire arrangement and thereby in a reduction of the service life.

Abstract: For continuous production of qualitatively high-grade lactose monohydrate crystals from a solution, the invention proposes the preparation of a highly concentrated solution in a falling film evaporator, from the pre-concentrated solution, which is then subjected to continuous cold crystallization with forced circulation and from which a lactose suspension is drawn off that forms the product crystals following separation of the transported solution. The product crystals are thereby obtained directly by solid/liquid separation, without further crystallization steps from the suspension that was drawn off from the cold crystallization. A portion of the mother solution separated off from the product crystals is fed back to a point prior to the inlet to the falling film evaporator, the remainder of the mother solution is discarded.

Abstract: The disclosure describes a system that uses an active filter connected to phases of a three-phase power grid in parallel with a resistance welding apparatus in order to bring an input current of a welding converter closer to a sinusoidal shape.

Abstract: A method for charging an intermediate-circuit capacitor for a welding device, includes feeding a voltage from a first chopping section of a first half-cycle of an AC voltage into the intermediate circuit capacitor, the first chopping section beginning at a first phase-related starting time; and feeding a voltage from a second chopping section of a second half-cycle of the AC voltage following the first half-cycle into the intermediate circuit capacitor, the second chopping section beginning at a second phase-related starting time, which is earlier than the first phase-related starting time.

Abstract: The disclosure describes a system that uses an active filter connected to phases of a three-phase power grid in parallel with a resistance welding apparatus in order to bring an input current of a welding converter closer to a sinusoidal shape.

Abstract: The service life of the power semiconductors of a resistance welding device largely determines the reliability of the installation in operation. The disclosure proposes a method for monitoring the remaining service life of power semiconductors that are exposed to current during the operation of a resistance welding device. The fact that, when there is a change of load of at least one power semiconductor, the change in a power semiconductor parameter is determined and the service life of the power semiconductor is determined while taking into consideration a setpoint selection that is representative of the remaining service life allows the reliability of the installation to be drastically improved.

Abstract: The invention proposes a method and a device for continuously producing a crystallite, wherein a metered amount of seed crystals is fed continuously to the internal solution circuit of a crystallizer, in particular a DTB crystallizer, through a crystallization seed line from a seed generator preferably designed as a flash crystallizer. The amount of seed crystals fed is controlled by an electronic control system as a function of a measured value determined by a sensor, said value being representative of the particle size distribution of the crystallites in the solution in the internal circuit in the crystallizer. By way of a line, the seed generator receives a partial stream of the external solution circuit of the crystallizer, said external circuit being routed through a line. Excess fine crystalline suspension can be fed back to the external circuit from the seed generator by way of a return line.

Abstract: The invention provides a compact and economical welding control system having an integrated power section. To this end, a switching module is provided for the power section of a welding control system. The switching module has a switching device, at least one cooling body, a current supply and an insulating element which provides a potential-free coolant arrangement. The invention is advantageous in that the potential-free coolant arrangement allows the coolant bodies to be shortened so that less space is required inside the control system and the control system can therefore have a more compact structure. The invention enables even the requirements in terms of the coolant bodies to be reduced, allowing the use of cost-effective cooling tubes or even cooling pipes that are directly connected to the cooling body.

Abstract: A method and installation for the production of a coarse-grained ammonium sulfate product by crystallization includes firstly generating a crystal having a grain smaller than the desired grain size in a pre-crystallizer and withdrawing a suspension therefrom, from which the fine crystal was previously separated in a classification connecting piece. This suspension, which contains medium-sized grain, is then conducted with a proportion of undersaturated mother liquor, which is sufficient for further crystal growth, into a DTB product crystallizer and crystallized therein to a desired grain size. The heating of the product crystallizer is performed by the heat contained in the vapors of the pre-crystallization. The pre-crystallization may also operate according to the DTB principle, wherein the mother liquor needed for crystallization is supplied in the form of separately admixed concentrated sulfuric acid and ammonia into the external solution loop of the pre-crystallizer.

Abstract: The invention proposes a method and a device for continuously producing a crystallite, wherein a metered amount of seed crystals is fed continuously to the internal solution circuit of a crystallizer, in particular a DTB crystallizer, through a crystallization seed line from a seed generator preferably designed as a flash crystallizer. The amount of seed crystals fed is controlled by an electronic control system as a function of a measured value determined by a sensor, said value being representative of the particle size distribution of the crystallites in the solution in the internal circuit in the crystallizer. By way of a line, the seed generator receives a partial stream of the external solution circuit of the crystallizer, said external circuit being routed through a line. Excess fine crystalline suspension can be fed back to the external circuit from the seed generator by way of a return line.

Abstract: A method and installation for the production of a coarse-grained ammonium sulfate product by crystallization includes firstly generating a crystal having a grain smaller than the desired grain size in a pre-crystallizer and withdrawing a suspension therefrom, from which the fine crystal was previously separated in a classification connecting piece. This suspension, which contains medium-sized grain, is then conducted with a proportion of undersaturated mother liquor, which is sufficient for further crystal growth, into a DTB product crystallizer and crystallized therein to a desired grain size. The heating of the product crystallizer is performed by the heat contained in the vapors of the pre-crystallization. The pre-crystallization may also operate according to the DTB principle, wherein the mother liquor needed for crystallization is supplied in the form of separately admixed concentrated sulfuric acid and ammonia into the external solution loop of the pre-crystallizer.

Abstract: The invention provides a compact and economical welding control system having an integrated power section. To this end, a switching module is provided for the power section of a welding control system. The switching module has a switching device, at least one cooling body, a current supply and an insulating element which provides a potential-free coolant arrangement. The invention is advantageous in that the potential-free coolant arrangement allows the coolant bodies to be shortened so that less space is required inside the control system and the control system can therefore have a more compact structure. The invention enables even the requirements in terms of the coolant bodies to be reduced, allowing the use of cost-effective cooling tubes or even cooling pipes that are directly connected to the cooling body.

Abstract: In the metallurgical treatment of metals, metal melts and/or slags in a metallurgical unit or melting vessel, especially in electric arc furnaces, injection devices (1) are used for blowing in or up oxygen-rich gases (6) and/or carbonaceous substances, which cause as long as possible gas jet (6?) with a high pulse energy to strike to strike the surface of the slag or metal. It is known to envelope produced gas jet (6?), thereby focusing it. According to the invention, such an envelope is obtained by using a hot gas (5, 5?) that is preaccelerated to such a degree that the central gas jet (6?) is preferably without pulse losses.

Abstract: The invention originates in the field of resistance welding technology, among other means by means of welding robots 1, for use in roll seam welding, projection welding or spot welding, and has to do with accommodating components for operation inside the housing 2 of the welding tongs. Taking the demands in terms of weight into account, the object of the invention is to achieve the most effective possible utilization of space for the housing 2 of the welding tongs carried by the welding robot. The housing 2 of the welding tongs is given a module 3 for this purpose. This module 3 includes modular components that are relevant to performing the welding process that is monitored by the welding controller.