GB854456A - Improvements in or relating to liquid dispensing systems - Google Patents

Abstract

854,456. Delivering measured quantities of liquids. CLEMENTS, C. A. June 3, 1958 [June 4, 1957], No. 17728/58. Class 106(5) [Also in Group XXIX] A liquid dispenser, particularly for beer, comprises a pair of cylinders 14 having pistons 20 linked by ball-ended rods 19 to a second pair of pistons 8 interconnected by a closed hydraulic circuit, a control valve 23 by which beer from a pressurized source 1 can be directed to one or other cylinder 14 to force out the contents of a cylinder through an outlet 26, and an expansion chamber 65 connected to the lower air spaces 18 of the cylinders 14 to act as a cooling system on each operation of the dispenser. During initial assembly of the dispenser, the pistons 8 are withdrawn into their cylinders 38 and the spaces 42 are completely filled with hydraulic fluid and then one rod 19 is pushed in to expel air and fluid from a bleed valve 17 until the rod has reached a position giving the required stroke of the piston 20 for the measured quantity desired. To prevent the beer foaming in warm weather, the speed of delivery may be reduced by adjusting a needle valve 16 in the hydraulic circuit. The control valve plug 52 has two passages 53, 54, the delivery passage 54 being of greater cross-section and arranged to connect the filled cylinder to atmosphere at the outlet before the passage 53 connects the other cylinder to the pressurized source 1. Counting means may be connected to the valve 23 and a bleed valve 24 is provided in front of it. In their uppermost positions, the pistons 20 seal against bosses 29 and these bosses are slightly off-centre in order to move the pistons slightly and allow them to centre themselves. The air spaces 18 are connected to the expansion chamber 65 by pipes 64 and to atmosphere by drain cocks 60 and non-return pressure relief valves 15A. As one piston descends, the compressed air in the space 18, containing beer evaporated from the walls of the cylinder 14, expands in the chamber 65 and gives off heat through a conductive cover 69 and then is sucked into the other space 18 as the latter expands. Alcohol, or other refrigerant may be added to the chamber 65 through a plug 62. A spring- loaded valve 66, for relieving excessive vacuum or for draining, is fitted to the chamber 65. An enclosing and insulating cover 10 is provided.