Patent GB-154187-A (GB)
Title: Improvements in and relating to mercury, vapour and like rectifiers
IPC: H01J13/50
Filed: 1920-11-09
Abstract: 154,187. Tschudy, W. Nov. 17, 1919, [Convention date]. Metallic - vapour apparatus. - A mercury or like vapour rectifier is provided with means for regulating and stabilizing the temperature and the pressure of the mercury vapour and of a permanent gas, with means for moving at least one of the electrodes, preferably the cathode, and with a separate vapour path to a condenser. In the construction shown, a cathode mercury cup 16, Fig. 1, preferably of quartz, is secured to a threaded rod 20 mounted on a spider 21, Fig. 2, the supporting-plate 22 of which is rotatable in ball-bearings 25 by means of a stem 26 and handle 27, to raise the cathode towards the anodes for starting the arc. Rotary movement of the cup 16 is prevented by a stop 37 engaging with a projection 38. Mercury seals 34, 29 are provided for conical bearing-surfaces 30, on the stem 26 and housing 24. The cup 16 may alternatively be operated by an electric motor geared with the stem 26, or, as shown in Fig. 3, by means of a solenoid winding 49, the spring-controlled tubular core 54 of which is secured to the cup, an airtight joint with the solenoid casing being made by a flange 44, iron and asbestos washers 46 and a mercury seal 47. Connexion with the cathode is made through a rod 52 and a flexible cable 53. The adjustment of the cathode may be automatic. The cathode may be fixed, and one or more anodes adjustable. Each anode consists of a water-cooled casing 18 integral with the wall 10 of the main container, the arcing surface 68, Fig. 4, being of non-oxidisable metal, insulated from the casing 18 by fibre 67, and connected through a rod 69 with a tubular lead 76. An airtight joint is made by means of a bevelled porcelain tube 70, iron washers, a mercury seal 74, and a fibre nut 77 bearing against a collar 75 on the rod 69. A vapour-condensing chamber 64 has a quartz tube 65 extending into a shield 66 on the cathode-cover 61, which is provided with anode shields 63 and with draining-passages 42. The wall 10 is lined with quartz or enamel 41. One or more water cooling jackets 78, 79, 80 may be provided, the water being circulated between the jackets and one or two coolers 81, 82 by means of a pump 84, the supply to each jacket being controlled by valves. A solenoid may operate a valve to control the circulation in accordance with the loss of energy in the rectifier. Thermostaticallycontrolled electric or steam-heating coils 83 may be mounted in the anode-jackets to prevent freezing when the rectifier is not being used, and the water may be circulated by means of a paddle, 104. A separate cathode may be provided for each anode. The pressure in the rectifier may be controlled by connecting it either with a tank 107 containing air, neon, hydrogen, nitrogen, carbon monoxide, &c., or with a vacuum pump 106, through a three-way valve having a conical member 108, Figs. 5 and 6, which connects a pipe 110 with either of two pipes 111,112. The valve has a conical bearing-plug 116 with mercury seals 117, 118. The passages 120 surrounding the member 108 are connected with the vacuum-pump. The valve may be operated by hand, or electrically in accordance with the reading of a pressure-gauge or wattmeter. In a modification two valves are used for connecting the rectifier with the pump or the air-tank, and may be actuated by solenoids controlled by a watt-loss indicating-instrument. The rectifier may be connected with the supplymains directly, or through a three-phase, or three single-phase transformers, and the transformer may be cut out of circuit after starting. The heating and control circuits may be connected to a separate transformer, with or without autotransformers, or to the continuous-current side of the rectifier. The cathode mav be connected through the load with the neutral point of the generator or transformer, or with an artificial neutral.