Process and apparatus for loading a particulate solid into a vertical tube

A process is described in which an elastic fluid is contacted with a particulate solid. This comprises providing a substantially vertical elongate tubular containment zone ( 1 ) containing a charge of the particulate solid ( 5 ), the volume of the containment zone ( 1 ) being greater than the settled volume of the particulate solid ( 5 ). An upper retainer means ( 3 ) is mounted at the upper end of the containment zone ( 1 ), the upper retainer means ( 3 ) being permeable to the fluid but adapted to retain particulate solid ( 5 ) in the containment zone ( 1 ). A follower means ( 4 ) is movably mounted in the containment zone ( 1 ) beneath the charge of particulate solid ( 5 ) for movement upwardly from the lower end of the containment zone ( 1 ) upon upward flow of elastic fluid through the containment zone ( 1 ) at a rate beyond a threshold rate. In the process the elastic fluid is caused to flow upwardly through the containment zone ( 1 ) at a rate which is sufficient to cause particulate solid ( 5 ) to rise up towards the upper end of the containment zone and form a cushion of particulate solid ( 5 ) against the underside of the upper retainer means ( 3 ). This rate is in excess of the threshold rate so as to cause the follower means ( 4 ) to move upwardly until it abuts against the underside of the cushion of particulate solid ( 5 ). The invention also provides an apparatus suitable for carrying out such a process and a method of loading a particulate solid into a substantially vertical tube.