Abstract: A process for the electrochemical regeneration of a co-enzyme, which process comprises the steps of(i) electrochemically oxidizing a medium containing oxidized co-enzyme and biochemically inactive isomers of the co-enzyme to oxidize the biochemically inactive isomers,(ii) generating a mercury amalgam in an electrochemical cell;(iii) contacting in a reaction vessel the mercury amalgam and the medium containing the oxidize co-enzyme from step (i), with one of the reactants selected from the mercury amalgam and the oxidized co-enzyme being in the form of a plurality of droplets.

Abstract: A process for making ferritic spheroidal graphite iron uses no pig iron but instead melts medium manganese and low silicon content steel scrap in an electric furnace with about 3% by weight of low sulphur content graphite. When the melt reaches 1400.degree. C. it is deslagged. Sufficient graphite is then added to bring the carbon up to at least 3% again and before or after this event, returns may be added to the melt while the furnace electric power is on to induce stirring of the melt. The melt is superheated next to above 1470.degree. C. and carbon and silicon correction is made. This is followed by inoculating the melt and pouring the castings.

Abstract: An electromagnetic valve for use for discharge of molten metal from a container comprises a body (1) providing a discharge passage (2, 3) surrounded by an electrical induction coil (4), the passage having a first portion (2) adjacent the container having a radius greater than that of a second portion (3) extending from the first portion to the discharge end of the passage, whereby the frequency of the electric current supplied to the coil (4) can be chosen independently of the passage discharge diameter.

Abstract: Known techniques of plasma case hardening of workpieces may fail to provide sufficient treatment to re-entrant portions, such as fine holes, in the workpiece. This specification discloses a technique of pulsed plasma treatment in which the duration of the plasma pulses and the intervals between them are selected to allow a substantially even distribution of the gas which forms the plasma over all the surface to be treated of the workpiece.

Abstract: The apparatus comprises a pair of opposed coil assemblies between which a workpiece to be heated is moved, each coil assembly including a plurality of loop windings arranged generally in a plane parallel to the plane of movement of the workpiece between the coil assemblies, the windings being arranged in pairs with the windings in each pair being aligned transversely in the direction of movement of the workpiece, adjacent end portions of the windings of each pair being turned to extend substantially perpendicularly to the plane of the remainder of the windings and away from the plane of movement of the workpiece. The arrangement allows the width of the coil assemblies to be altered in dependence upon the width of a workpiece to be heated.

Abstract: An induction heater comprising an alternating-current-carrying conductor (1) extending along an axis; a plurality of core sections (3, 4, 5) arranged in line and each substantially encircling the axis to guide magnetic flux resulting from the alternating current in the conductor (1); a plurality of heating element sections respectively associated with the core sections and each comprising an electrically conductive closed loop encircling magnetic flux in the associated core section (3, 4, 5) and being heated by electrical current induced thereby; and means (13, 14) to at least partially saturate at least one (4, 5) of the core sections thereby to reduce the coupling between the conductor (1) and the heating element section associated with said one core section (4, 5) and thus control the heating effected by said one core section (4, 5) and its associated heating element section (FIG. 4).

Abstract: An electromagnetic valve for use for discharge of molten metal from a container, comprises a main body providing a discharge passage through which, in use, molten metal will flow; and electrical induction coil located about the passage; means to supply an alternating electric current to the coil whereby the coil provides an alternating magnetic field which induces electric currents in any molten metal in the passage; and a center member located in the passage, the arrangement being such that interaction between the magnetic field provided by the coil and the currents induced in the molten metal in the passage provides a force which as it is increased causes the flow rate of the molten metal through the valve to be reduced until the force is sufficient to urge the molten metal away from the wall of the passage until the molten metal is supported on the center member and the flow of molten metal is cut off.

Abstract: Excess currents due to faults in an electrical power system are generally larger than excess currents due to the magnetization of distribution transformers. Discrimination has hitherto relied on a threshold detector. Magnetizing currents are, however, asymmetrical, whereas fault currents are symmetrical. A detector detects symmetrical current waveforms on a conductor 1 and thus discriminates between a fault and a magnetizing excess current. A resistor 4, placed across the output terminals of a bridge rectifier 3 has a resistance selected so that the voltage across it exceeds the breakdown voltage of trigger diodes 7 and 8 when the current in conductor 1, in any half cycle, exceeds a desired maximum. Capacitors 13 and 14 will thus only both charge up in response to an excessive symmetrical current. A logic control 23 is connected via lines 21 and 22 to detect such a condition.

Abstract: In a method of baking using an open face container a radio frequency field is applied between the container and the material to be baked therein in order to enhance the heating of the material and thus shorten the baking time. The method can be used in a conventional oven of, for example, the convection type.

Abstract: It is desirable to provide remote digital protection of distribution transformers. This specification discloses a protection system able to measure and compare increases in both negative and positive phase reference currents on a distribution cable feeding a transformer and to trigger a circuit breaker to isolate the cable only if the negative sequence current increase exceeds a predetermined proportion of any simultaneous positive sequence current increase. Consequently, engergizing with a 12.5% unbalance current has been found possible without false tripping.

Abstract: The simultaneous heating and mixing of a fluid in a vessel with heated walls and a stirring device can lead to excessively high temperatures at the walls due to the formation of a thick boundary layer. This specification discloses a stirring paddle incorporating a heated element and mounted on a rotatable shaft. The heating element is connected in series with a rotor winding mounted on the shaft so that, when the shaft rotates, a heating current flows through the heating element.

Abstract: A charge-load support for use in a glow discharge furnace comprises first and second coaxial tubular members joined at one end and capped at the other end to provide a re-entrant entry to the space between the members, the outer member serving to protect the inner member against conductive deposit build-up thereon and the members together defining a relatively long convoluted path from the capping member to the other end thereby serving to reduce the risk of tracking in use of the support.

Abstract: An induction heater has a conductor loop (1) in which a large alternating current is induced by a toroidal primary transformer (8). An annular secondary magnetic core (4) encircles a straight length of the conductor loop (1) and is itself enclosed by inner and outer cylinders (2 and 5) interconnected by annular end plates (6 and 9). The current in the conductor (1) produces magnetic flux in the core (4) which in turn produces axial heating currents in the cylinders (2 and 5). The inner cylinder (5) may have heated fins (3). An alternative embodiment has an inductively heated screw.

Abstract: The invention relates to channel induction furnaces employed for melting metals.A channel is arranged to extend downwardly from a bath and to form a loop whereby molten metal in the bath can pass into the looped channel to form a closed electrically conducting loop. A laminated iron core passes through a coil and forms a closed magnetic circuit linked with the coil and channel. Consequently, alternating current applied to the coil induces currents to flow in the molten metal in the channel, which metal is therefore heated. The molten metal is contained in the channel within a refractory lined vessel. With application of the alternating current to the coil electromagnetic forces are produced which are directed away from the walls of a channel. Thus a squeezing action is applied to the metal which produces an increase in static pressure towards the center of the channel relative to that at the wall. This pressure fluctuates from zero to a maximum value at twice the frequency of the induced current.

Abstract: Dielectric, cooling or arc-extinguishing fluids comprise a mixture of tetrachlorodifluoroethane and perchloroethylene, optionally with incorporation of a third component which is preferably trichlorotrifluoroethane. Transformer and circuit-interrupter apparatus containing such dielectric fluids are also described.

Abstract: A method of isolating a spur line of an electrical power system protected by a multi-shot resetting circuit breaker wherein at least two successive current surges in the spur line which activate the circuit breakers are detected. In response to the detection the spur line is isolated during a subsequent current dead period.A sectionalizer is described for isolating a spur line of an electrical power system protected by a multi-shot resetting circuit breaker. The sectionalizer comprises a metal casing 22 providing a current path across a fuse mounting 10 while the sectionalizer is in a conducting position. An electrical circuit 23 inside the tube detects at least two successive current surges in the casing and during the following dead period actuates a chemical actuator 14 to trip the sectionalizer out of its conducting position.

Abstract: An electrical circuit interrupting device such as a circuit breaker or switch has openable contacts immersed in a first relatively dense liquid, such as a perfluorocarbon, constituting an arc interruption medium and has a second less dense non-flammable dielectric liquid e.g. a halogenated liquid such as perchloroethylene or trichlorobenzene or carbontetrachloride constituting a coolant forming a second phase above the first liquid.

Abstract: An electrochemical cell having dished electrodes received in rectangular frame members, and arranged to form a bipolar stack. Electrolyte inlets and outlets open into plenum chambers defined between the dished electrodes and the frame members. A turbulence promoter substantially fills the flowpath between the electrolyte inlet and electrolyte outlet.

Abstract: A method of regenerating a spent metal etchant solution and the metal which has been etched therewith, comprising circulating the spent etchant solution between an etching vessel and the anode compartment of an electrolytic cell provided with a cell divider, for example an anion or cation exchange membrane defining the said anode compartment and a cathode compartment, and electrolytically re-oxidizing the reduced etchant in the cell to regenerate the etchant in the anode compartment and the etched metal in the cathode compartment while introducing a portion of the circulating etchant solution into the cathode compartment, for example by pumping solution from the etching vessel, or by gravity, the said portion being sufficiently small as not to raise the level of etchant in the cathode compartment to a level which will prevent the said electrolytic reduction of ions of the etched metal.

Abstract: In the induction heating of rotationally symmetrical workpieces, the workpieces are passed through the treatment region with magnetic flux in the region parallel to the axis of symmetry of each workpiece as it passes through the treatment region. In order to obtain uniform heating of the workpieces, flux modifying members are provided which are arranged so that the resultant distribution, across the workpiece transversely of the axis thereof of the magnetic flux density in the axial direction is substantially inversely related to the distance from the axis of rotational symmetry of the workpiece.