POPULATION OF ACTIVE SITES IN NUCLEATE BOILING HEAT TRANSFER

Journal Article · Fri Jan 01 04:00:00 EST 1960 · Chem. Eng. Progr.

OSTI ID:4034625

Gaertner, R F; Westwater, J W

>Counts of active bubble-producing sites were determined throughout most of the nucleate region for a boiling liquid. An aqueous solution of nickel salts containing 20% solids was boiled at atmospheric pressure on a horizontal, flat, copper surface 2 in. in diameter in a 71/2-in. vessel with no forced convection. The technique for determining active sites consisted of plating a thin layer of nickel on the copper surface during the boiling runs and subsequently counting the number of pin holes in the plate. The heat flax was varied from 7,680 to 535,000 Btu/(hr) (sq ft) and the DELTA t from 17.3 deg to 216.8 deg F. Counts of active sites were obtained from zero to a maximum of 1,13O/sq in. at 317,000 Btu/(hr) (sq ft). A random geometrical distribution of active sites was revealed by a photographic study of the nickel-plated heated surface. For this system a linear relationship between the number of active sites and the heat flux, as suggested by Jakob, is nonexistent. The heat flux was proportional approximately to the square root of the number of sites. Widely known theoretical analyses for nucleate-boiling heat transfer do not include the functionality in the latter manner. (auth)

• Research Organization: General Electric Co., Schenectady, N.Y.
• NSA Number: NSA-15-023636
• OSTI ID: 4034625
• Journal Information: Chem. Eng. Progr., Journal Name: Chem. Eng. Progr. Vol. Vol: 56: Symposium Ser. No. 30
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BOILING
BUBBLES
COATING
CONFIGURATION
CONVECTION
COPPER
DISTRIBUTION
EFFICIENCY
ENGINEERING AND EQUIPMENT
HEAT TRANSFER
HEATING
JACOB CORRELATION
LIQUIDS
NICKEL
NICKEL COMPOUNDS
NUCLEATE BOILING
PARTICLES
PHOTOGRAPHY
QUANTITATIVE ANALYSIS
QUANTITY RATIO
SOLUTIONS
SURFACES
TEMPERATURE
VARIATIONS
VESSELS
ZONES