GB701764A - Fluid proportioner - Google Patents

Abstract

701,764. Fluid proportioning apparatus.. BOWSER, Inc. Feb. 4, 1952 [Feb. 13, 1951], No. 2929/52. Class 86 Apparatus for proportioning at least two fluids in flow includes a meter for each fluid, means for adding together the speeds of the meters, a speed change mechanism associated with each meter and driven by the adding means, the speed total of the outputs of the speed change mechanisms being equal to the speed total of the meters, and their individual outputs bearing a speed ratio equal to the required fluid proportion ratio, and means for altering the rate of flow of a fluid in response to a difference between the speed of the corresponding meter and the speed at the output of the associated speed change mechanism. In the arrangement shown.. liquids in supply lines 15 are discharged in predetermined proportions into a manifold 21 by means of electrically powered pumps 13, the rates of flow of the liquids being controlled by valves 12 which are automatically adjusted if the rates of flow of the liquids, as measured by flow meters 9, depart from the required ratio. The output shaft of each meter 9 is coupled to a differential gear mechanism 27, the differential gearing mechanisms being coupled together by shafts 35, 35<SP>1</SP>, whereby a final shaft 35" runs at a speed equal to the sum of the speeds of the meter shafts 23. The rotation of the shaft 35<SP>11</SP> is transmitted by a unity ratio chain drive 41 to a shaft 43 to which are coupled speed change mechanisms 45, each of which includes an adjustable speed change gear and a differential mechanism which enable the speed of rotation of the shaft 43 to be divided in a desired proportion, between output shafts 47 of the devices 45, the selected ratio, being the ratio desired between the component liquids supplied over the lines 15. Each shaft 47 is axially aligned with and rotates in the same direction as a shaft 24 of one of the differential mechanisms 27, which shaft 24 is driven at the speed of the corresponding- meter shaft 23. Each shaft 24 drives a nut 29 which is in screw-threaded engagement with the shaft 47, the arrangement being, such that a difference in speed between any pair of shafts 24, 47 causes an axial displacement of the nut 29 which is transmitted to the corresponding valve 12 in a direction such that the change in rate of flow of liquid as measured by the corresponding meter 9, tends to restore the equilibrium of the nut 29. The resulting change in the speed of this meter causes the speed of the shaft 43 to slightly change thus causing a corresponding change in the speed of the shafts 47 whereby an adjustment of the valves 12 in the other lines 15 is secured, the overall effect serving to maintain the fluids in the lines 15 in the predetermined proportions. Excessive movement of the nuts 29 in either direction operates switch means to open the circuit supplying electric power to the pump motors 17. The Specification describes in detail the differential mechanisms 27 and the speed change mechanisms 45.