Abstract: A vertical cylinder for drying and heating granules which includes an inlet at the top of the cylinder, a conically tapered outlet at the bottom of the cylinder, a rotatable screening ring beneath the inlet, a chute beneath the screening ring and a scraper above the ring inlets for gases in the downward extending section of the cylinder, a shell and tube heat exchanger located coaxially in the bottom quarter of the cylinder, a horizontally movable grid as flow control device below the heat exchange and a discharge zone below the grid.

Abstract: A process for the preparation of acetic acid esters CH.sub.3 --CO--O--R.sup.1 (I, R.sup.1 =an organic radical other than methyl and ethyl) by alkali-catalyzed trans-esterification of an acetic acid ester CH.sub.3 --CO--O--R.sup.2 (II, R.sup.2 =methyl or ethyl) with an alcohol R.sup.1 --OH (III), accompanied by elimination of the alcohol R.sup.2 --OH (IV), wherein(a) the trans-esterification reaction is carried out in the middle section K.sub.M of a distillation column K, the alcohol III being fed as liquid into the upper zone and the ester II into the lower zone of K.sub.M,(b) the alkaline catalyst is introduced into the upper part K.sub.U of K,(c) the alcohol IV, or a mixture of IV and the ester II, is taken off the top of the column,(d) the mixture obtained from (c) (unless the alcohol IV alone is obtained) is separated in the column section K.sub.U or in a stripper column K.sub.S into IV and the azeotrope of II and IV, and the latter is recycled to the lower zone of K.sub.

Abstract: A process for completing the esterification of aliphatic carboxylic acids of 1 to 8 carbon atoms with aliphatic or cycloaliphatic alcohols of 3 to 10 carbon atoms at the boiling point of the alcohol in a column operated with bottom heating, the lower space of the column being free from fitments, the middle space being provided with a packing and the upper space being provided with a packing or other fitments, in which process the water of esterification is driven off at the top of the column by azeotropic distillation, the starting mixture is fed into the side of the column from 5 to 10 m above the liquid level, the ester formed is taken off as liquid from the column bottom, and the column is operated with flooding such that the liquid level is from 6 to 10 m, with the liquid mixture filling the lower column space, which is free from fitments, and the lower part of the packed layer above the said space.

Abstract: In a process for drying and heating nylon granules, in which the granules flow downwards through a vertical zone, hot inert gases which are free from molecular oxygen are passed in counter-current through the granules and the cooled granules are then intermittently discharged in part-streams, the improvement wherein the wet granules, or a suspension of the granules in water, are fed into the zone at the top, the granules are deposited as a layer, the water is led away, the layer of granules is then transferred into the next-lower part of the zone, the granules are there allowed to flow under gravity downwards through the zone, and inert gases which are free from molecular oxygen are passed in countercurrent upwards through the granules at from 70 to 200.degree.