GB1368523A - Fluid metering and mixing device - Google Patents

Abstract

1368523 Reciprocating pumps L J CARLYLE 4 Oct 1972 [5 Oct 1971] 45784/72 Heading F1A [Also in Division B1] Apparatus for dosing a primary liquid flow with metered quantities of an additive comprises a transparent cylindrical housing 2 having a piston 13 with a coaxial passage 15 therethrough closed by a bottom closure member 20 carried on a stem 21 passing through the passage 15. A cage 22 is bolted to the bottom of the piston 13 and carries a plunger 24 which in the position of the piston shown in Fig. 1 is entered into a cylinder 34 formed in a plug 32. Primary liquid enters at 10 and carries the piston 13, closure member 20 and cage 22 together up the cylinder 2, forcing liquid ahead of them out of an outlet (11), Fig.2 (not shown) in the cap 3; additive is drawn through the valve 40 into the cylinder 34 as the plunger 24 rises. At the top of the cylinder 2 the spring 29 strikes the cap 3 causing the member 20 to separate from the bottom of the piston 13 and open the passage 15; the piston 13, member 20 and cage 22 then sink to the bottom where the plunger 24 re-enters the cylinder 34 forcing the contents thereof past the valve 39 Fig. 9 into the cylinder 2. The legs 30 strike the bottom cap 4 causing the closure member 20 to rise and again close the passage 15, and the cycle recommences. The quantity of additive pumped on each cycle may be altered by adjusting the plug 32 along the screw 33. With increase in the rate of flow of the main liquid, the proportion of additive will tend to deminish since while the movable parts are descending in the cylinder 2, there is unobstructed flow between the inlet 10 and outlet (11) through the passage 15. In modifications the member 20 may be a flap hinged to the piston 13; a spring may be used to cause the moving parts to descend instead of relying on gravity (see Fig. 10, not shown); the piston 13 may be replaced by a flexible diaphragm Fig.11 (not shown); the additive pumping plunger may be fixed and the cylinder form part of the cage 22 Fig. 12 (not shown); the valve 39 may be located in the plug 32 Fig. 13 (not shown); the piston may have a plurality of narrow passages to delay its descent Fig. 14 (not shown); the closure member may lie on top of the piston 13 Fig. 17 (not shown); or the passage 15 and closure member 20 may be replaced by a fixed tube (96), Fig. 18 (not shown) having a flap valve (93) actuated by a striker pin (110) on the piston. The apparatus may be used to introduce a bloat control agent into animal drinking water, in fertilizer and weed control systems, and for mixing oil and petrol.