Process for continuous contacting of liquids and particle form solids countercurrently

Claim 1

IN A PROCESS FOR CONTACTING LIQUIDS AND SUBDIVIDED SOLIDS IN ORDER TO BRING ABOUT A CHANGE IN THE CONDITION OF AT LEAST ONE OF THE MATERIALS CONTACTED, WHEREIN A LIQUID HAVING A VISCOSITY UNDER CONTACTING CONDITIONS WITHIN THE RANGE OF ABOUT 0.2 TO 500 CENTIPOISES IS PASSED IN A CONFINED CONTACTING ZONE UPWARDLY THROUGH A COLUMNAR MASS OF DOWNWARDLY MOVING SOLIDS OF PALPABLE, PARTICULATE FORM, MADE UP ESSENTIALLY OF PARTICLES FALLING WITHIN THE SIZE RANGE OF ABOUT 0.0058 TO 0.185 INCH AVERAGE DIAMETER AND WITHIN THE LOOSE PACKED APPARENT DENSITY RANGE OF ABOUT 0.45 TO 1.3 GRAMS PER CUBIC CENTIMETER, AND CONTACTED LIQUID IS WITHDRAWN FROM THE UPPER SECTION OF SAID ZONE, AND CONTACTED SOLID PARTICLES ARE WITHDRAWN FROM THE LOWER SECTION OF SAID ZONE, WHILE THE COLUMNAR MASS IS REPLENISHED WITH SOLID PARTICLES INTRODUCED INTO THE UPPER SECTION OF SAID ZONE, THE IMPROVED METHOD IN COMBINATION THEREWITH FOR EFFECTING TRULY COUNTERCURRENT CONTACTING WHICH COMPRISES; CONTROLLING THE FLOW RATE AND VISCOSITY OF THE LIQUID PASSING UPWARDLY THROUGH SAID COLUMNAR MASS OF DOWNWARDLY MOVING PARTICLES IN EXCESS OF THAT WHICH FIRST CAUSES A PRESSURE DROP PER GIVEN UNITS OF COLUMNAR MASS HEIGHT AND CROSS-SECTION, DUE TO FLOW OF LIQUID THROUGH THE MASS OF DOWNWARDLY MOVING PARTICLES, EQUAL TO THE DIFFEENCE BETWEEN THE WEIGHT OF THE WETTED PARTICLES AND THE WEIGHT OF THE VOLUME OF LIQUID DISPLACED BY THE WETTED PARTICLES PER THE SAME UNITS OF COLUMNAR MASS HEIGHT AND CROSS-SECTION, WHERE THE PRESSURE DROP, COLUMNAR MASS HEIGHT AND CROSS-SECTION AND WEIGHTS OF LIQUID AND WETTED SOLIDS ARE EXPRESSED IN CONSISTENT UNITS, WHEREBY SUBSTANTIALLY ALL OF THE PARTICLES ARE ESSENTIALLY SUSPENDED IN THE LIQUID IN THE SENSE THAT ANY SUCH PARTICLE IS ESSENTIALLY UNSUPPORTED BY SURROUNDING PARTICLES, FURTHER CONTROLLING THE FLOW RATE AND VISCOSITY OF SAID LIQUID TO LIMIT THE EXPANSION OF SAID COLUMNNAR MASS TO AN EXTENT THAT ESSENTIALLY ALL OF SUCH SUSPENDED PARTICLES ARE SURROUNDED SUFFICIENTLY CLOSELY BY OTHER SUCH PARTICLES TO PREVENT ESCAPE FROM THEIR REGIONS OF CONFINEMENT BY SURROUNDING PARTICLES, AT LEAST ONE OF THE FLOW RATE AND VISCOSITY OF THE LIQUID BEING INCREASED, WHENEVER NECESSARY, TO MAINTAIN SAID PARTICLES ESSENTIALLY SUSPENDED IN SAID LIQUID AND BEING DECREASED, WHENEVER NECESSARY, TO LIMIT THE EXPANSION OF SAID COLUMNAR MASS BELOW THAT AT WHICH THE INDIVIDUAL PARTICLES WOULD BE FREE TO ESCAPE FROM THEIR REGIONS OF CONFINEMENT BY OTHER PARTICLES, THE VOLUMETRIC EXPANSION OF SAID COLUMNAR MASS BEING LIMITED IN ANY CASE BELOW ABOUT 30 PERCENT OF THE NORMALLY SETTLED VOLUME OF THE OIL-WETTED MASS.