Abstract: A process for separating an extract component from a raffinate component contained in a feed mixture. A unidirectional fluid flow system is maintained through a series of separating units through which the components travel at different rates. A component concentration distribution is established within the system of units and divided into specific zones. Feed and displacement fluid are passed into the inlets of two of the units and extract and raffinate are taken as the entire streams from outlets of two of the units all at appropriate points on the component concentration distribution. Other inlets and outlets of the various units lying in the same zone are interconnected. At the appropriate times the inlets and outlets are shifted so as to simulate movement of the units in a direction co-current with the fluid flow and thereby enable the inlets and outlets to continually lie in the appropriate zones. Zones may be combined as zone pairs, each such pair thereupon being considered a single continuous zone.

Abstract: A process for separating an extract component from a raffinate component contained in a feed mixture. A unidirectional fluid flow system is maintained through a series of separating units through which the components travel at different rates. A component concentration distribution is established within the system of units and divided into specific zones. Feed and displacement fluid are passed into the inlets of two of the units and extract and raffinate are taken as the entire streams from outlets of two of the units all at appropriate points on the component concentration distribution. Other inlets and outlets of the various units lying in the same zone are interconnected. At the appropriate times the inlets and outlets are shifted so as to simulate movement of the units in a direction co-current with the fluid flow and thereby enable the inlets and outlets to continually lie in the appropriate zones.

Abstract: Exhaust emissions control system provides effective control of hydrocarbons, carbon monoxide, and nitrogen oxides by adjusting the air-fuel ratio of an internal combustion engine having a catalytic converter in its exhaust path in response to the percentage oxygen content of the exhaust gases as measured by a voltage generating oxygen sensor positioned in the exhaust path. The electrical signal produced by the oxygen sensor is compared to a set point signal which corresponds to the desired oxygen content which prevails when the conversion of the exhaust gases is optimized and a correcting step adjustment is made in the air-fuel ratio when there is a difference in the signals. To minimize hunting and still provide a relatively rapid response, the system incorporates a time delay to permit each adjustment made in the air-fuel ratio to be reflected in the output of the exhaust gases before the oxygen content of such exhaust gases is sensed preliminary to make succeeding step adjustments.

Abstract: There is a drastic change in the composition of the effluent streams of a fixed bed adsorption column when the feed and withdrawal points are periodically advanced in order to simulate moving-bed operation. These effluents are fractionated to recover a desorbent which is recycled to the adsorption column. The claimed process improves the efficiency of this fractionation by changing the locations at which the effluents enter the fractionators to correlate the compositions of the effluents and the material in the fractionators at these locations.

Abstract: A liquid-liquid extraction process utilizing a tower having perforated contacting trays. The discontinuous flow of the denser downward moving stream prevents the backmixing of this stream on the contacting trays and increases the efficiency of the extraction.