Liquid emptying, rate

Provide 1 SCFH of air per eveiy 7.5 gph of maximum emptying rate for liquids of all flashpoints. 

Use maximum liquid flow out of tank (considered as oil by code) as equivalent to 560 cubic feet of free air per hour for each 100 barrels (4,200 gallons) per hour of maximum emptying rate. This applies to oils of any flash point. Also includes gravity flow conditions. 

Beckers EJ, Leiper JB, Davidson J. Comparison of aspiration and scintigraphic techniques for the measurement of gastric emptying rates of liquids in humans. Gut 1992 33 115-117. 

Heading, R. C.,Tothill, R, McLoughlin, G. P., and Shearman, D. J. C. (1976), Gastric emptying rate measurement in man. A double isotope scanning technique for simultaneous study of liquid and solid components of a meal, Gastroenterology, 71,45-50. 

The rate of gastric emptying is dependent on a complex interplay between physiological conditions and the composition of the ingested meal. Liquids empty faster than solids, mainly because the pylorus holds back larger food particles until further breakdown has taken place (Moore et al., 1983). Gastric emptying is also dependent on the caloric content of the meal and there seems to be a dynamic feedback mechanism between the stomach and the duodenum to control the caloric delivery (Brener et al., 1983). 

The liquid flow rate passing through a bubble column is usually very low. The gas throughput on the other hand may vary widely according to the specified conversion level. The normal ranges of liquid and gas superficial velocities, based on empty reactor cross-sectional area, are in the region of 0 to 3 cm/s) and 3 to 25 cm/s), respectively. 

Gardner-Holt viscosity tubes n. Series of selected glass tubes of constant, standard diameter, which is filled with liquids of various viscosities, except for a small air space at the top. When these tubes are inverted, the air bubble travels through the liquid, and the rate of travel is a measure of the viscosity of the liquid. Empty tubes of similar standard dimensions are filled with liquids of which the viscosity is required, and the rates of travel of the bubbles compared with those of the tubes containing the liquids of known viscosities. Viscosities are compared under controlled temperature conditions (Paul N. Gardner Co. Inc., 316 N. E. Fifth Street, Pompano Beach, FL, www.gardco.com). 

Acetylcyclohexanone. Method A. Place a mixture of 24-6 g. of cyclohexanone (regenerated from the bisulphite compound) and 61 g. (47 5 ml.) of A.R. acetic anhydride in a 500 ml. three-necked flask, fitted with an efficient sealed stirrer, a gas inlet tube reaching to within 1-2 cm. of the surface of the liquid combined with a thermometer immersed in the liquid (compare Fig. II, 7, 12, 6), and (in the third neck) a gas outlet tube leading to an alkali or water trap (Fig. II, 8, 1). Immerse the flask in a bath of Dry Ice - acetone, stir the mixture vigorously and pass commercial boron trifluoride (via an empty wash bottle and then through 95 per cent, sulphuric acid) as fast as possible (10-20 minutes) until the mixture, kept at 0-10°, is saturated (copious evolution of white fumes when the outlet tube is disconnected from the trap). Replace the Dry Ice-acetone bath by an ice bath and pass the gas in at a slower rate to ensure maximum absorption. Stir for 3 6 hours whilst allowing the ice bath to attain room temperature slowly. Pour the reaction mixture into a solution of 136 g. of hydrated sodium acetate in 250 ml. of water, reflux for 60 minutes (or until the boron fluoride complexes are hydrolysed), cool in ice and extract with three 50 ml. portions of petroleum ether, b.p. 40-60° (1), wash the combined extracts free of acid with sodium bicarbonate solution, dry over anhydrous calcium sulphate, remove the solvent by... 

---