Abstract: A method and apparatus for simultaneously measuring the streaming potential of a fiber suspension and a filtrate thereof. A container is provided having an inlet and an outlet for the flow of fiber suspension therethrough, and a filter screen divides the container into an upstream compartment and a downstream compartment. Each compartment has an electrode pair disposed therein, each electrode pair including a cylindrical outer electrode configured for flow of fiber suspension therethrough and an inner electrode. Each electrode pair is connected to a differential amplifier, with the differential amplifiers connected to a microprocessor.

Abstract: A heat exchanger for transferring heat between an inner and outer medium with a tube bundle for transporting the inner medium. The tube bundle being a plurality of tubes forming concentric rings of tubes. The tubes have angular progressions and are corrugated their entire length; thus adjacent tubes can contact without fatally increasing mechanical tensions. A shell surrounds the tube bundle. An inner medium connector transports the inner medium to and from the tube bundle. An outer medium connector transports the outer medium to and from the shell; the outer medium flowing around the tube bundle inside the shell.

Abstract: A particle suspension from a process is introduced into a measuring vessel 1 and caused to rise above a screen 4 whereupon the streaming potential of the suspension is determined by measuring the voltage across the screen at alternately different, relatively low pressures. The measurements may be carried out continuously with the measuring vessel being rinsed between measurements. The apparatus comprises a vertical U-shaped measuring vessel 1 in which a horizontal screen plate 4 in one leg 3 defines a measuring chamber 9, the other leg 2 being supplied with the suspension. Valves V4-V8, V10 are provided to alternately subject the vessel to different measurement pressures, and to provide a high rinsing pressure. Adjacent its center the screen plate supports electrodes 5, 6 for measuring the voltages between particle suspension and filtrate, and an electrode 11 is associated with the screen plate for measuring the conductivity of the suspension.

Abstract: A two-circuit heat exchanger is characterized in that the heat exchange tube(s) of each circuit is/are formed with non-circular cross-section to exhibit at least partially plane side surfaces, said side surfaces of the tubes in the two circuits being in heat-exchange relationship with one another.

Abstract: A load-weighing device for indicating the weight of a load is provided for attachment to the load-carrying member of a lifting device. The load-weighing device includes a frame connected to the load-carrying member and a bearing block mounted in the frame for rotation relative to the load-carrying member. A clearance space is provided between the lower surface of the bearing block and the frame which is eliminated upon the application of a load. A bearing member is also mounted in the frame and includes a cylindrically-shaped lower surface which is arranged to abut a cylindrically-shaped upper surface of the bearing block. The bearing member is provided with a recess for receiving a pressure-sensitive member so that when a load is lifted by the load-carrying member, the force of the load is transferred to the pressure-sensitive member which operates to provide a load-measuring value to a receiver.