Abstract: A control system for a stand-alone electrical generator driven by a prime mover such as a wind turbine in which switches are operable in response to changes in the frequency of the generator output to change the load imposed on the generator by resistor means. The resistor means includes domestic resistive heaters and dump resistors, the switches for the former turning "on" at frequencies lower than those at which the latter turn "on". The frequencies at which the several switches in a given consumer's premises switch "on" are interlaced with the frequencies of the switches in other premises so as to avoid discrimination between consumers. The output frequency is thus kept relatively constant despite changes in wind speed.

Abstract: An electric switch has an arc interrupter mounted in a housing between two main conductors. The interrupter comprises a fixed contact having a first arcing surface, a fixed electrode having a second arcing surface, an arc-driving coil and a movable contact, the surfaces and the coil being coaxial with one another and the contact being mounted for angular movement about a pivot axis between a make position and a break position. During opening of the interrupter, an arc is initially struck between the contacts after which it is transferred from the contact to the electrode. The coil, now being part of the arc current path, produces a magnetic flux which interacts with the arc so that it is driven around the axis between the surfaces. That movement of the arc assists in extinguishing the arc at an appropriate current zero. Ferromagnetic material forms part of the magnetic circuit of the coil. Two interrupters can be arranged in series between the main conductors.

Abstract: A device discrimates between relatively shorter and relatively longer intervals by means of an interceptor member which:(a) if an interval between a displacement thereof away from and a displacement thereof towards an intercept station is less than a predetermined interval, intercepts a rotor at a first position; or(b) if said interval is greater than said predetermined interval, does not intercept the rotor which can then move to a second position.The member is movable by an electromagnetic mechanism, e.g. a coil and armature arrangement.Displacement of the member away from the station propels the rotor towards a stop. After striking the stop, the rotor returns towards the first position and, if not intercepted thereat, moves on to said second position.The device shown has a flag on the rotor for providing an indication of, e.g., operation. However, the device could be a relay, for example, instead of an indicator.

Abstract: An extensometer, for use in determining extensions or creep in studs or bolts for example, has a first tubular member in which slides a tube assembly carrying a second collet-like member. First and second abutment formations on the first and second members, respectively, engage internal shoulders in a stud. Upper and lower brackets which are restrained against separation, by a spring, beyond a datum position, are fixed relatively to the first and second members, respectively. A dial gauge (0.01 mm divisions), which co-operates with a datum block on the lower bracket, is mounted on the upper bracket. With the extensometer in position, the spring is stressed by relatively moving the first and second members to position the second abutment formation below the lower shoulder in the stud. A plunger member is moved relative to the second member to expand the spring fingers thereof outwardly. The spring is allowed to relax and pull the second abutment formation into contact with the stud shoulder.

Abstract: A high degree of water purity is obtained from a mixed-bed deionization process by minimization of cross-contamination of the cation and anion materials. After service, the materials are classified into superimposed uppermost, intermediate and lowermost layers above a perforate barrier in a separator vessel. The vessel has an elongate conduit having an inlet adjacent the barrier and an outlet outside the vessel. At least a major proportion of the material of the lowermost layer is passed through the outlet of the conduit and an interface between materials is detected. Thereupon, the conduit outlet is isolated from the conduit inlet so as to segregate in the conduit material from the intermediate layer. The ion exchange materials are then regenerated and re-mixed. The segregated material is independently removed from the conduit before the next regeneration cycle starts.

Abstract: In a method of regenerating mixed ion exchange materials, the materials are classified into layers. The lower layer is then transferred from the separator vessel. The transfer is controlled by detecting an interface between materials. The separated materials are then regenerated after which the anion material is reclassified to allow any contaminant cation material to settle to the bottom thereof. Material is then removed from the bottom of the anion layer to remove settled contaminant cation material. The removed material is isolated from the regenerated materials which are then remixed.The method reduces the cross-contamination of materials that occurs during the separation of classified materials and, particularly, reduces the amount of cation material in the sodium form (following regeneration of the anion material) that is eventually returned to service.

Abstract: A fluidized bed shell boiler for producing steam or hot water or a fluidized bed hot gas generator or incinerator in which the position at which bed material is deposited downstream of the bed is controlled. A baffle of firebrick with gas-flow passages extending through the baffle is positioned in the tube downstream of the bed.Gas velocities are distributed across the tube so that bed material is preferentially deposited in the combustion chamber downstream of the furnace tube.Deposition in the furnace tube is reduced to zero or to a negligible amount and deposition downstream of the combustion chamber is reduced.

Abstract: A circuit-breaker has a fixed contact, a movable contact and coil for rotating the arc. The components are mounted in a casing containing pressurized gas having arc-extinguishing properties. The fixed contact is connected to a second end of the coil, the first end of which is connected to a first terminal. The movable contact is carried by a hollow movable contact member which is electrically connected to a second terminal. The contact member has ports which control communication between a first chamber in the casing in which the fixed contact is located and a second chamber in the casing in dependence upon the position of the contact member. Ferromagnetic material is positioned adjacent the coil which is coaxial with the line of movement of the contact member.

Abstract: A boiler or other fluidized bed apparatus has an outlet from the bed and an outlet from the gas stream downstream of the bed for removing material from the bed and from the gas stream. The material removed is passed to screening mechanism which separates materials into relatively larger particles and relatively smaller particles. The smaller particles are fed by conveyor to means feeding the bed. The larger particles are mainly ash which is discarded. Removal of material from the bed under load is provided for.

Abstract: Flutter of the tip sections of the blades of an axial-flow steam turbine wheel is inhibited by interconnection of the blades by ball-ended elongate members which are pre-stressed in compression. Each member exerts thrusts on two adjacent blades to pre-stress the blades torsionally each in a sense corresponding to untwisting of the blades. The thrusts are each exerted on the respective blade through socket elements received in respective openings in the blades. Either one or each socket element of each member is in screw-threaded engagement in its opening. Where only one is so engaged, the other is a close sliding fit in its opening.