GB715886A - Improvements in apparatus for adding one liquid to another in required proportionality - Google Patents

Abstract

715,886. Purifying water. UNITED FILTERS & ENGINEERING, Ltd. Feb. 12, 1952 [Feb. 12, 1951], No. 3356/51. Class 46. [Also in Group II] Chemical reagent maintained at a constant level in a tank 2, Fig. 1, is discharged therefrom, at a rate depending e.g. on the pressure difference existing across an orifice 14 in a pipe 8 conveying water, through an orifice 6 in the bottom of a floating bucket 3 and a flexible pipe 18 leading from the bucket, the head on the orifice 6 and hence the rate of flow therethrough being governed by the depth of immersion of the bucket, which is in turn governed by its buoyancy in relation to the differential pressure on the piston 10 to which it is connected. The outlet from the tank 2 leads to a mixing tank (not shown) to which the outlet end of the pipe 8 also leads. Where it is necessary to situate the differential pressure device below the chemical reagent tank 2 the bucket 3 is provided with an upstanding tube 29, Fig. 4, slidable over a hollow post 30 upstanding from the floor of the tank 2, the tube 29 being connected by a wire cable 31 to the piston rod 11. Where reagent liquids bearing a high percentage of suspended solids which might choke up the orifice 6 are to be used the liquid is fed tangentially to a settling tank 41, Fig. 7, and thence by a pipe 43 tangentially to a tank 39 in which is disposed a bucket 3 connected to a differential pressure piston as before. The bucket carries a conical valve 36 co-operating with an orifice 38 in a pipe 44 leading to a mixing tank 45. The level in tanks 41 and 39 is maintained by an overflow 42. Systems incorporating the forms of Figs. 1 and 4 are described and depicted.