GB840613A - Automatic constant rate sample feeder for liquids - Google Patents

Abstract

840,613. Delivering measured quantities of liquids. STANDARD OIL CO. Sept. 29, 1958, No. 31083/58. Class 106(5) [Also in Group XXVIII] Apparatus for supplying measured quantities of liquid to a measuring instrument 24 at a controlled rate comprises a measuring chamber 10 having an air supply 18 connected to it through a pressure regulator 19 and flowrestricting capillary 20, a float 13 co-operating with an inlet 14 and an outlet line 22 leading to the instrument 24 through a flow-restricting capillary 23. Liquid is poured into the container through a screen 12 and funnel 11 until the float closes the inlet and any excess in the funnel is drained off through tubes 15 and a capillary syphon 25 to an overflow line 17. With the seating of the float, the air pressure built up in the chamber operates a switch 21 to start the instrument 24 and displaces the contents of the chamber at a controlled rate through the capillary 23, which is larger than the capillary 20. When the chamber is fully discharged and air passes through the capillary 23, the air pressure decreases and the float drops, thus lowering the pressure again so that the switch 21 stops the instrument 24. The float is ballasted at 26 so that it is about two-thirds submerged in the liquid and does not seat before the chamber is filled to its maximum level; a plunger 13a may be used to depress the float and vent any trapped air before discharging the chamber.