ENGINEERING PROPERTIES OF POTASSIUM. Quarterly Report No. 11, April 1- June 30, 1963

Technical Report · Tue Jul 30 04:00:00 EDT 1963

OSTI ID:4687722

Lemmon, Jr, A W

Measurements of the viscosity, vapor pressure, thermal conductivity, and heat content of liquid potassium have been concluded. In addition, vapor compressibility has been measured in the P-V-T apparatus. Also concluded has been the design study of equipment for the direct determination of the specific heat of potassium vapor. The vapor pressure and compressibility data were used to derive a virial equation of state which, in turn, was used for the computation of enthalpy, entropy, and the specific heat of the vapor; the specific heat values of the vapor are currently reported. Experimental effort is currently limited to the final assembly of the apparatus for measuring the thermal conductivity of potassium vapor and its subsequent operation. The thermal conductivity and electrical resistivity of liquid potassium have been measured to about 1150 deg C and the experimental results are reported. The data are considered to be reliable to about 800 deg C, and from 87 to 781 deg C they can be expressed by k = 0.543--0.333 x 10/sup -3/ t, where k is the thermal conductivity in watts cm/sup -2/ cm deg C/sup -1/ and t is temperature in degrees C. Above 800 deg C, extrapolation by means of the average Wiedemann-Franz- Lorenz constant of 2.14 x 10/sup -8/ watt-ohm C/sup -1/ and the observed electrical resistivity values is recommended. Leakage of potassium within the apparatus probably explains the anomalous behavior of the thermal conductivity data between 800 and 1150 deg C. Activity on the experimental program directed at the measurement of the viscosity of potassium vapor has been indefinitely suspended. Values for the specific heat of potassium vapor have been computed from known thermodynamic relations and the virial equation of state previously derived in this program from experimental data obtained. A graphical representation is presented. Effort has continued on the design and construction of the dynamic, bare-wire probe apparatus for the measurement of the thermal conductivity of potassium vapor. In addition, estimates of convection effects have shown them to be negligible for short times but radiation effects have been estimated to be extremely significant. Radiation will represent about 75 per cent of the heat trasferred from a bare-wire probe 0.001 inch in diameter at 1200 deg C. Proper and essentially continuous calibration will be necessary to subtract the radiation mode in the measurements. Assembly of the apparatus followed by the experimental measurements is planned. (auth)

• Research Organization: Battelle Memorial Inst., Columbus, Ohio
• NSA Number: NSA-17-041432
• OSTI ID: 4687722
• Report Number(s): NP-13228
• Country of Publication: United States
• Language: English

Related Subjects

DIAGRAMS
ELECTRIC CONDUCTIVITY
ENTHALPY
ENTROPY
EQUATIONS
HIGH TEMPERATURE
LABORATORY EQUIPMENT
LIQUID METALS
MEASURED VALUES
METALS, CERAMICS, AND OTHER MATERIALS
PLANNING
POTASSIUM
PRESSURE
RADIATION EFFECTS
SPECIFIC HEAT
TEMPERATURE
THERMAL CONDUCTIVITY
THERMODYNAMICS
VAPORS
VISCOSITY