GB147334A - Improved liquid-level gauge - Google Patents

Abstract

147,334. Kelvin, Bottomley, & Baird, and Field, M. B. June 13, 1919. Indicators actuated by pressure of head of liquid.-Apparatus is provided whereby the plane of demarcation between two non-miscible liquids in a tank, e.g., oil and sea-water in a fuel-tank of a ship, is indicated at a distance. The tank 5 is assumed to contain oil in its upper portion, which is displaced by sea-water entering by the pipe P. Two tubes 3 and 4 are connected at one end with gauge glasses 1, 2 and at the other end with the sea and with the oil in the tank 5 respectively; preferably the pipes are kept adjacent to one another to equalize the temperature conditions. The upper ends of the gauge glasses are provided with valves C', C<2> whereby they may be connected together or to a closed chamber 6. The chamber 6 is provided with a cock 7 communicating with the atmosphere, and is connected to a supply of air under pressure by means of the valved pipe 8. Seawater is first admitted to the chamber 6 through the pipe 3, and is then driven out through the pipe 4 by admitting air under pressure. The gauge glasses 1, 2 are then put into communication with one another at the top, a quantity of air being trapped above the liquid. The difference in level in the two gauge glasses then indicates the difference in head of a column of sea water between the bottom of the tank and the end of the tube 4, and the corresponding column of water and oil actually existing in the tank. A movable graduated scale 10 may be used to measure the difference in level. The scale may be marked to indicate not only the position of the plane of demarcation in the tank, but also the weight or volume of the oil or water or both, in the tank. A single indicating-instrument may be made to serve for a number of similar tanks, or separate instruments with a common chamber 6 may be used if the tanks are dissimilar.