Abstract:
A method to extract bitumen or very heavy oil in situ from oil sand seams close to the Earth's surface is provided. Energy is introduced via at least two pipes at a given, repeatable distance from the seam, a predefined geometry is maintained in relation to the well pair. The associated apparatus includes at least one additional pipe which is alternatively designed as an electrode or also for feeding vapor and is placed above the injection pipe.
Abstract:
An apparatus for the in situ extraction of bitumen or very heavy oil from oil sand deposits, and applying heat energy to the deposit to reduce the viscosity of the bitumen is provided. A high-frequency generator feeds electric power to a linearly extended conductor loop at a predefined depth of an oil sand deposit, the inductance of the conductor loop is compensated in some sections or continuously. Advantageously, one of the conductors of the conductor loop may be disposed substantially in a vertical direction above the extraction pipe.
Abstract:
A gradient coil system for a magnetic resonance tomography apparatus has a layer structure including a gradient coil layer and a cooling layer. The cooling layer is fashioned as a plate heat exchanger, composed of plates, for cooling the gradient coil layer. In this way, a highly efficient cooling of the gradient coil layer is achieved with a lower structural height compared to conventional tubular configurations.
Abstract:
A charging circuit for a frequency converter having a first feed line with a first constant current source therein and a second feed line with a second constant current source therein. An intermediate circuit capacitor connected between the first feed line and the second feed line, wherein the first constant current source that limits a charging current of the intermediate circuit capacitor. An electronic control device that controls both the first constant current source and the second constant current source in parallel.
Abstract:
A method for weaving fabrics that comprise in at least some sections multiple layers, especially one-piece woven (OPW) airbags comprising single-layer, double-layer and multi-layer sections. Weaves or weave combinations are produced in the double- or multi-layer sections that are different from the plain weave.
Abstract:
A fixed stator is arranged around a rotatably mounted rotor in an electric motor that includes at least one cooling unit to which parts of the stator which are to be cooled are thermally coupled by a line system in which a cooling agent circulates according to a thermosyphon effect. The stator parts to be cooled can be arranged in the inner region of a stator housing which is integrated into the line system. The electric motor can be provided with a heating device to maintain the pressure in the inner region when the motor is stopped.
Abstract:
A method for ground potential monitoring of a rectifier drive, having a capacitor which is connected with a voltage source via a switching device. The method including applying a test voltage between a connector of a capacitor of a rectifier drive and a mass or ground potential prior to connecting the rectifier drive with a voltage source that is connected with the capacitor via a switching device. The method also includes releasing the switching device if a potential of the connector changes by a predetermined amount after the applying the test voltage.
Abstract:
A measuring device is provided in which a graduated plate is scanned in at least two scanning locations. The scanning signals from the different scanning locations are transmitted to a testing circuit which determines whether the phase displacement between the scanning signals exceeds a limit value. If the limit value is exceeded, one of the scanning locations is weighted higher than the other. The weighting is implemented by increasing the components of the signals from one scanning location while decreasing the components from the signals from the other scanning location.