Patent GB-438895-A (GB)
Title: Improvements in or relating to vapour electric converters
IPC: H01J13/22
Filed: 1934-05-24
Abstract: 438,895. Metallic - vapour converters. GENERAL ELECTRIC CO., Ltd., Magnet House, Kingsway, London, and GALLIZIA, E., c/o General Electric Co., Witton, Birming- ham. May 24, 1934, Nos. 15520 and 30364. [Class 39 (i)] A converter is provided with a liquid cathode and with baffles which are controlled automatically in dependence upon the temperature of the converter, or upon a state or characteristic which varies therewith, to control the vapour flow from the cathode in such manner that an increase of the density of the vapour in the arc path is effected when the temperature is low. The vapour flow from a cathode 6, Fig. 1, to the water-cooled condensing chamber 5 is controlled by movable and fixed baffles 8, 17. The baffle 8 is registered by guides 18, secured to a cross-piece 19, and is fixed to a stem 9 which is vertically adjustable by the screw 11. Rotation of the screw is effected by an induction motor, the steel rotor 14 of which is housed within the vacuum chamber 15, surrounded by the stator 13. The motor is energized from an auxiliary supply 16 through a contactor 20 which is biassed by a spring 21 to a position in which the baffle is fully opened. A solenoid 22 connected, in series with a rectifier 23, between the cathode and an anode, is adapted when the voltage drop in the arc exceeds a predetermined value, e.g. 35 volts, to operate the contactor to close the opening in the member 17. A solenoid 24 is connected across a shunt 25 in the output circuit to act in opposition to the solenoid 22. In other forms, the vapour flow is directed towards the mouths of the anode shields upon the occurrence of a low temperature. A baffle 33, Fig. 2, may be lowered to deflect the vapour in conjunction with a flanged sleeve 31. The baffle is secured to an iron rod 34, which extends through the top plate 35 into an exhausted container 36 and carries a spring 38 and a soft-iron head 37. Solenoids 39 are energized by switching means in dependence upon the temperature to vary the position of the baffle. In another form, the baffle 33 is secured through spacers to a flanged cylinder to form an opening for the vapour, the cylinder sliding over the sleeve 31. The baffles may be operated by thermostatic means. Circularly arranged anodes 40, Fig. 3, are housed in anode shields 41, between which are arranged vanes 46 adapted to rotate about their axes by bimetallic spirals 48 which are mounted on the top plate through means which are formed of material of good thermal conductivity. Alternatively, bimetallic spirals may be provided only, or additionally, at the bottom of the vanes, or all the vanes may be connected to a common operating means. When the converter is cold the vanes close the spaces between the shields to prevent the flow of vapour therethrough. The vanes may be arranged to open gradually or with a snap action, e.g. by means of a toggle arranged to move against a spring across a dead centre. The shields, on those sides remote from the cathode, may be extended towards the bottom of the converter. A converter, as described in Specifications 433,649 and 434,879, is provided with a divergent nozzle 62, Fig. 5, for deflecting the vapour into the condensing chamber formed by the walls 54, 55. A cylindrical baffle 64 is mounted through rollers on helical guide rails 66, secured to the screen 54, and it is vertically adjustable by rotating means which consists of an induction motor 67 and a flexible metal cord 69. The motor is energized by a contactor 71 which is controlled by a solenoid 73 actuated by a thermostatically operated relay 70. In a further form, the opening into the condensing chamber is closed by fixed and rotatable plates. The movable plate is secured to a stem which is supported through a flanged disc in an annular bath of mercury and is driven by an induction motor.