Patent GB-879687-A (GB)
Title: Continuous sorption process
Inventor: BROUGHTON DONALD BEDDOES
IPC: B01D53/04
Filed: 1959-07-03
Abstract: <PICT:0879687/III/1> <PICT:0879687/III/2> In a continuous absorption process for separating a mixture of gaseous components, such as the fractionation of hydrocarbons, in which one component is selectively absorbed during contact with a solid absorbent, there is a continuous circulation successively through at least four serially connected processing zones of a stationary mass of solid absorbent from the outlet of the last zone back to the inlet of the first zone and the mixture is continually introduced into the circulating fluid at the inlet of the first zone, the unabsorbed component is continuously withdrawn from the circulating fluid at the outlet of the first zone, desorbent is continuously introduced into the circulating fluid at the inlet of the third zone, and selectively absorbed component and desorbent are continually withdrawn from the circulating fluid at the outlet of the third zone, by simultaneously advancing the point of introduction of said charge mixture, the point of withdrawal of an absorbed component, the point of introduction of desorbent and the point of withdrawal of selectively absorbed component and desorbent being periodically advanced one increment along the path of flow of said circulating fluid.  The four zones are advanced through the stationary mass so as to use all portions of the bed for all the parts of the process.  As shown, a contacting column 101 contains suitably shaped partitioning means 102 which divide the vertical column into a series of adjacent bed zones 201 to 212 each with a construction as in zone 201 with downcomer 103 of restricted cross-sectional area opening into a sub-adjacent zone 202 through a transverse partitioning member 104 which comprises the upper boundary of the zone 202.  A circular valve 105 (Fig. 2) has a valve housing A and a continuously revolving plug B rotatable in the housing A in fluid-sealed relationship with the housing A. The latter housing contains a number of inlet and outlet ports 1 to 12 connecting in fluid flow relationship with internal passageways inside the valve plug through which certain inlet and outlet fluid streams enter and are withdrawn from fixed beds in contacting column 101.  The valve plug is arranged to provide at least 4 passageways for accommodating at least two separate inlet streams and at least two separate outlet streams, the two inlet passageways alternating with the two outlet passageways.  Although it is generally preferred to arrange the inlet and outlet passageways in the valve plug approximately 90 degrees apart, thereby positioning the outlets and inlets on opposite sides of the plug, it is feasible to provide any suitable arrangement of ports and passageways and thereby increase or decrease the angular relationship between the respective inlet and outlet passageways, depending upon the relative number of fixed beds of sorbent to be assigned to the different stages of the operation. The number of fluid inlet and outlet ports 1 to 12 in the valve 105 corresponds to the number of contacting zones or fixed beds 201 to 212 in column 101.  The ports are positioned within housing A at finite and predetermined distances apart to direct inlet and outlet streams into and from column 101 to correspond to the desired programme, prearranged for the process.