The production of uniform liquid sheets from spinning cups

Abstract

An investigation has been made of the effect of liquid flow disturbances within a spinning cup on the uniformity of the sheet centrifuged from its lip. It has been found that, except for a limited range of operating conditions, a spinning cup is not capable of smoothing out the flow of liquid over its surface solely under the action of centrifugal force, and the sheet uniformity is critically dependent on the method of feed distribution, feed rate and viscosity. When the feed is stationary with respect to the cup and the flow rate is greater than 200 lb/hr and/or the viscosity is less than 40 cS, upstream flow disturbances produced as the liquid impinges on the cup walls propagate along the walls to the lip with consequent detriment to the sheet uniformity. Where the feed distributor rotates with a cup and is designed to distribute the liquid uniformly into a damping reservoir at the back of the cup, uniform sheets are produced over a wide range of operating conditions.