DEVICE FOR COMPARING THE FLOW RATE OF A LIQUID PETROLEUM PRODUCT AT DIFFERENT TEMPERATURES

摘要

1522275 Recording flow characteristics of a liquid SOC NATIONALE ELF AQUITAINE 14 Jan 1977 [15 Jan 1976] 01506/77 Headings G1D and G1S A device for recording the flowability of a liquid such as a petroleum product as a function of temperature comprises a vessel 2 for containing a sample of the liquid, a sensing member 12 immersed in the liquid, a piston 13 connected to member 12 and mounted in a tube 9 above the vessel, means for moving the piston 13 up the tube to effect movement of member 12 through the liquid, means for lowering the temperature of the liquid, means 6 for sensing the temperature of the liquid, and means for measuring the time taken by the piston to move a predetermined distance. The member 12 may be of metal foil, and may be S-shaped, cylindrical or rectangular, Figures 2, 3, 3a, 3b (not shown). Piston 13 is raised within tube 9 by means of negative pressure applied via a solenoid valve 34. When the piston has risen the predetermined distance, its arrival at a mark 17 is detected photo-electrically, and a control unit 33 then closes solenoid valve 34 and the piston and member 12 fall under gravity. The temperature in the vessel is lowered by means of a low temperature bath 24 containing liquid which may be cooled in a refrigerator unit 27. Unit 27 is connected to the bath by ducts 28, 29, and a solenoid valve 30 in duct 29 is controlled to maintain the temperature in the bath at a fixed difference to the temperature of the test liquid in vessel 2. The device may be used to determine the lowest temperature at which the liquid can be pumped.