GB1304957A - - Google Patents

Abstract

1304957 Plasma generators SIEMENS AG 25 June 1970 [1 July 1969] 30976/70 Heading H5H To maintain the coolant pressure in the cooling channels of the "hot parts" of a plasma burner in excess of the superatmospheric working gas pressure, the arc chamber 6, which contains the arcing electrodes 10 and 11 and has an outlet nozzle 5, is connected by pressure transmitting means 8 to a closed coolant circuit (Fig. 2) of which the cooling channels are part, the "excess" pressure being supplied by the coolant circulating pump 45. Electrode 11 is mounted on a wall 20 separating an adjustment chamber 2 from the arc chamber 6. The chambers 2 and 6 communicate through apertures 17 in wall, 20 The wall 20 supports one end of a spindle 22 carrying an adjustment head 23 driven by electric motor 21 to adjust the axial position of electrode 11. Arc rotating opposed field coils 12 are provided in each cylindrical electrode 10, 11. Plasma forming gas is supplied via duct 39 to the arc gap where it is directed radially, tangentially or axially to the nozzle. Subsidiary supply ducts 40 are provided in the ring segments 28 of the arc chamber. A current supply duct 15 on which current collector 26 slides supplies coolant to electrode 11, the exist duct not being shown. Coolant is passed to coils 12 by ducts 37 and to nozzle 5 by ducts 38. Coolant is also supplied from bore 34 in burner head 3 to the space between a division wall 31 and an electrode jacket 29 by which the electrode 10 is connected to terminal 14 and then flows along the passage formed between jacket 29 and coil 12 to the space between a further division wall 31 and end plate 32 before emerging from bore 35. In operation the burner 41 (Fig. 2) is connected by pressure transmitter 8, which may be a piston in a duet or as shown a compensating tank, to the closed coolant circuit. Thus the arc chamber pressure is transmitted to the coolant circuit. A monitor 43 interrupts the filling of the coolant circuit when it reaches a preselected level and stops operation as soon as the level falls below a predetermined level, e.g. on occurrence of leaks. Coolant is circulated via parallel pipes 48-53 through the movable electrode 11, the fixed electrode 10, the magnet coil 12 of the movable electrode, the magnet coil of the fixed electrode, cooling passages in ring segments 28 if provided, and nozzle 5 respectively. The coolant then flows through a heat exchanger 57, 58 and a heat exchanger 59 with fresh water supply 60 back to pump 45. Control valves 54, quantity metres 55 thermocouples 56 determine the energy given up to the coolant. The burner is used for chemical purposes and wind tunnels.