Some considerations on heat transfer in spiral plate heat exchangers

✍ Scribed by M.H.I. Baird; W. McCrae; F. Rumford; C.G.M. Slesser

• Publisher: Elsevier Science
• Year: 1957
• Tongue: English
• Weight: 347 KB
• Volume: 7
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(57)80027-x

✦ Synopsis

The sea-water samples used had a chlorinity of 16 and were obtained from the Firth of Clyde near the entrance to Loch Long. Their surface tension at IOWC was found to be 58.7 dyn/cm, as compared with 71.8 dyn/cm for a sample of freshwater.

The freshwater used for comparison was Glasgow City water.

The lower surface tension of sea-water further &onfirms the presence of surface-active agents.

The present results may also throw some light on the discrepancies between the values obtained by various authors for the velocity of rise in pure water of bubbles whose diameters lie between 0.8 and 4.0 mm BENFRA~~LLO [4] has summarized the literature available on velocity of rise in pure water, and inspection of his curves shows that a bubble with a diameter of (for example) 2 mm has been reported to rise with a velocity in the range 17 -24 cm/set. The explanation may be that the diameter range 0.8 -4.0 mm is a transition region where spiral, non-spiral, and intermediate types of rise can occur, and where the velocity of rise and the incidence of non-spiral motion are sensitive to dissolved impurities.