HEAT TRANSFER FROM ARCS

Journal Article · Mon Feb 01 04:00:00 EST 1960 · Brit. Welding J.

OSTI ID:4163118

Wilkinson, J B; Milner, D R

The energy distribution for arcs between a nonconsumable tungsten cathode and a water-cooled copper anode was determined in atmospheres of argon, nitrogen, helium, and hydrogen. In general, 80 to 90% of the er::-gv expended in an arc of this type was found to go to the anode, with the remainder divided between the cathode heating and the heat carried away by the gas, which leaves the arc region at temperatures of the order of 1000 to 6000 deg K. The investigation was directed to the examination of the heat flow to the anode, which comprises the electron heating, together with heat transfer from a plasma jet which originates from the constriction of the current caused by the cathode spot. The velocity and diameter of the jet in argon arcs were determined at the anode by comparing the pressure increase it creates with that caused by jets of known velocity and extent. It was found that the jet velocity is of the order of 10/sup 4/ cm/sec, and the diameter a few millimeters. The intensity of the jet in dissociable gases made measurements impossible because of the rapid erosion of the apparatus. For argon arcs the heat transfer from these high-velocity, high- temperature jets was separated from the heating caused by the electron stream in experiments with a three part anode, in which a center section received the electron heating together with some plasma jet heating, while a surrounding annulus was heated only by the plasma jet. Conventional heat transfer concepts were applied with some success to the interpretation of the data on heat transfer from the jet to the cooled anode. It is suggested that jets of this type in dissociable gases are responsible for deep-penetration effects in welding. (auth)

• Research Organization: Birmingham Univ., Eng.
• NSA Number: NSA-14-009575
• OSTI ID: 4163118
• Journal Information: Brit. Welding J., Journal Name: Brit. Welding J. Vol. Vol: 7, No. 2
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ANODES
ARGON
ATMOSPHERE
CATHODES
CONFIGURATION
COOLING
COPPER
DISTRIBUTION
ELECTRIC ARCS
ELECTRONS
ENERGY
ENGINEERING AND EQUIPMENT
GASES
HEAT TRANSFER
HEATING
HELIUM
HIGH TEMPERATURE
HYDROGEN
JETS
NITROGEN
PLASMA
PRESSURE
TUNGSTEN
VELOCITY
WATER
WELDING