GB879500A - Improvements in and relating to liquid feeding and measuring apparatus - Google Patents

Abstract

879,500. Mixing liquids in flow. HYDRAULIQUE & URBANISME S.a.r.L., and PONSAR, Y. M. March 10, 1960 [March 10, 1959], No. 8547/60. Class 86 In an apparatus for supplying an amount of reagent proportional to an output of water to be treated, the reduction of pressure in a pipe is a function of the flow of water and is used to control the metering of the reagent. In Fig. 4 the pyramidal and cylindrical containers 30, 33 are connected by a pipe 32 and contain fluid sufficient to fill completely the pyramidal container 30: An air blower 36 creates increased pressure in the pipes 31, 37 and reduced pressure in the pipe 35 and above the liquid in container 33. The bottom 39 of the pipe 37 is at the level of the weir 41 over which passes a flow of water Q; any rise in the level of the water flow causes a rise in pressure in the pipes 37, 31 which drives an amount of fluid proportional to the cube of the pressure out of 30 units 33. As the lower end of pipe 34 is subject to atmospheric pressure, the pipe 1 transmits to the metering apparatus, Fig. 1, and reduced pressure proportional to the cube of the difference between the reagent, the level of which is controlled by steam 40; that is, to the square of the quantity of water Q flowing over the weir. The metering apparatus, Fig. 1, comprises a container 3 supplied by pipe 2 with reagent, the level of which is controlled by a float valve 4 and weir 9 which cooperates with a pipe 10 and cap 8 to form a siphon discharge; the lower end of the pipe 10 has a trap 12. When the pipe 1 is at atmospheric pressure the level N of the reagent is level with the top of the weir 9 and there is no outflow. When the pressure falls in pipe 1, reagent is fed at a rate q proportional to the square root of the reduction in pressure, and hence in linear relationship with the rate Q of the water flow. The proportion of reagent may be adjusted by means of the screw cap 8 the lower edge of which co-operates with the weir 9 to form a metering passage. In another embodiment of the metering apparatus, Figs. 2 and 3 (not shown) and applicable to reagent in the form of a suspension, a metering orifice supplies a constant quantity of additive consisting of reagent and dilating water in varying proportions. A constant flow of dilating water equal to the total capacity of the metering orifice is supplied to the apparatus, and a proportion depends on the reduction in pressure in the pipe 1 is removed by an apparatus similar to that of Fig. 1, the difference being made up with reagent. In a modification of the apparatus of Fig. 1, (see Fig. 5 not shown) the main flow of water passes from a constant level through a gate into a second container, the difference in the levels in the containers being a junction of the square of the quality flowing out of the apparatus. The pipe 1 is connected to an elevated container the pressure in which is arranged to vary according to the difference in levels.