Abstract: A calorimeter for the measurement of a quantity of heat given up by a fluidic medium in at least one heat exchanger, with an impellerless flow velocity measuring device as well as temperature sensors for determining the forward flow-return flow temperature difference, including a multiplier for forming the product from the flow velocity and the forward flow-return flow temperature difference; and also a quantizer for the formation of a pulse train having a frequency which is proportional to the product, as well as a cumulative counting device for the pulses of the pulse train connected to the output thereof.

Abstract: A brushless D-C motor of the type having a permanent magnet rotor, a plurality of individual stator windings which are disposed 90.degree. apart with respect to each other, and at least two Hall-effect galvanomagnetic transducers which are disposed 90.degree. apart with respect to each other, and within the air gap of the motor. The galvanomagnetic transducers produce control signals in response to the angular position of the rotor for controlling the conductive states of semiconductive switching devices which are each electrically disposed in series with respective individual stator windings, and a controlled current generator which controls the current flowing through the stator windings so as to conform with a sinusoidal wave shape.

Abstract: A method and apparatus for the concentration of an alkaline solution to an approximately anhydrous melt using the falling-film principle under atmospheric pressure wherein the solution to be concentrated is conducted along the internal surface of evaporator tubes (1). Each tube (1) is surrounded by a heating jacket (2). The heating jackets (2) are fed with heat-transfer fluid from a conduit (6) which is common to all jackets. An annular collecting trough (8) is associated with the lower end of each evaporator tube (1). The metal running off from the tube (1) is collected by the trough (8) separately from the vapors. All of the troughs (8) are connected to a melt discharge line (9) which is also common to all troughs. The vapors descending in the tube (1), in contrast thereto, pass through the opening (8a) of the collecting troughs (8) into a collecting duct (10) which is common to all troughs.

Abstract: An alkaline solution film flowing from the top toward the bottom in falling-film evaporator tubes (1) is heated by a heat-transfer fluid flowing from the bottom toward the top in a narrow heating jacket (5). Since large temperature differences occur between the heat-transfer fluid and the alkaline solution film in the upper heated portion of the evaporator tube (1), in contrast to the lower portion, especially at high flow rate as it occurs in a narrow heating jacket (5), the heat flow density can at that location lead to a lack of wetting of the evaporator tube. To avoid such critical heat flow densities, the upper section (5a) of the heating jacket (5) is conically widened and thus the flow rate in this section is reduced to such an extent that a critical heat flow density is not reached at that point.

Abstract: The polarity of the desired speed voltage of a speed control device and the commutation sequence of the current flowing in the stator windings are reversed for reversing an electronically commutated D.C. motor. A voltage, proportional to the EMF ad obtained from the motor voltage by I.times.R compensation, is used as the actual speed voltage for the speed control device, the polarity of the voltage proportional to the EMF being reversed when the direction of rotation signal changes.

Abstract: In a control signal transmitter for the commutating device of an electronically commutated motor, which contains at least two rotor position transmitters, particularly Hall effect generators, and an evaluation circuit which derives control signals for the commutating device from the output signals of the rotor position transmitters which determine the individual switching instants for the switching elements of the commutating device, in order to permit operation with a higher number of pulses, the evaluation circuit also includes a logic circuit to which the output signals of the rotor position transmitters are fed which circuit furnishes further control signals for the commutating device.

Abstract: An electronic motor has a multi-pole external rotor and a multi-slot stator which is rotatable inside the external rotor. At least two magnetic field sensing elements are arranged in the vicinity of the external rotor and current supply to the stator windings is provided by a commutation device. The prior art stator was provided with obliquely set stator winding slots and involved a complicated winding technique. To eliminate this disadvantage and to be able to use slots lying parallel to the axis, the neutral field lines between each north and south pole of the external rotor are made to lie parallel to the rotor axis in the region of the magnetic field sensing elements and obliquely thereto in the region of the laminated rotor stack.

Abstract: A process for purifying a polluted fluid which comprises heating the polluted fluid and evaporating the components of said polluted fluid which are more volatile while simultaneously concentrating the pollutants into a residue, introducing said residue to a combustion chamber where it is at least partially burned and introducing the heat of combustion as the only source of heat to the evaporation stage of the process.

Abstract: A process and apparatus for purifying waste water which comprises introducing said waste water into a separation zone, removing a portion of the impurities recovered from said separation zone, and concentrating said impurities by their introduction into an evaporation system to form a still fluid residue and remaining impurities composed of impurities in gaseous and vapor form together with waste vapors, transferring said remaining impurities to an oxidation chamber, and supplying said oxidation chamber with heat and air, thereby oxidizing said remaining impurities through spontaneous combustion, wherein the proportion of the low boiling-point impurities in the waste water introduced into the separation zone is adjusted to a predetermined value.

Abstract: In a D.C. motor in which signals generated by an angular position transmitter control the commutation of the current flowing through the stator winding via a selection circuit containing Exclusive OR gates by means of which the polarity of the signals generated by the angular position transmitters can be reversed for the reversal of the direction of rotation, operating modes of "Operation" and "Braking" can be specified with only one command input for the Exclusive OR gates using an additional Exclusive OR gate.

Abstract: The heat transfer apparatus comprises a storage reservoir containing salt as a heat carrier with a heater connected into the reservoir to heat the heat carrier so as to maintain it above the freezing point. The heater may comprise an electric heater or a fluid which is circulated for example from a separate heat exchanger. An intermediate heat exchanger is connected so that the salt is circulated therethrough and in heat transfer relationship to an intermediate heat carrier such as a metal alloy which is circulated from a consumption heat exchanger. The intermediate heat exchanger is in heat exchange relationship with a consumption heat carrier.

Abstract: A commutation device for controlling a brushless d-c motor is disclosed. The commutation device includes a regulator circuit for regulating current supplied to the motor by means of a transistor connected between the power source and a commutation circuit. A threshold hysteresis level detector controls the transistor. During current peaks generated in the commutation circuit, the hysteresis of the level detector is increased to provide stable operation of the regulator with different motors and operating voltages.

Abstract: In a position control device for driving a speed controlled motor, the motor having coupled thereto a tachometer generator for providing velocity feedback, a brushless tachometer generator having at least one position transmitter for the rotor thereof is used as the tachometer generator and the position signals of the position transmitter also used to provide an actual value feedback for the position control.

Abstract: This invention is for apparatus used in combination with electronic commutation circuitry for a D.C. motor with a Y-connected stator winding wherein current control is accomplished by means of a cyclic current regulator. Current to the regulator is applied to the regulator by means of a series connected choke inductor and resistor, across which is connected in parallel a by-pass diode.