Abstract: A method of cleaning permeable, hollow membranes in an arrangement of the type wherein a pressure differential is applied across the walls of the permeable, hollow membranes immersed in a liquid suspension, the liquid suspension being applied to the outer surface of the porous hollow membrane to induce and sustain filtration through the membrane walls. The method of cleaning comprises the steps of applying a cleaning solution to one side of the membrane wall; applying a pressure differential across the membrane wall to cause flow of the cleaning solution through the wall from the one side of the membrane wall to the other side of the membrane wall and applying a reverse pressure differential across the membrane wall to cause flow of the cleaning solution through the wall from the other side of the membrane wall back to the one side of the membrane wall.

Abstract: A method of cleaning permeable, hollow membranes is disclosed. In one embodiment, the membranes are immersed in a liquid suspension. A pressure differential is applied across the walls of the membranes. During filtration, liquid suspension passes through the walls of the membranes to be drawn off as permeate, and at least some solids are retained on or in the membranes. The steps of cleaning include: applying a cleaning solution to one side of the membrane walls; applying a pressure differential across the membrane walls to cause flow of the cleaning solution through the walls from the one side of the membrane walls to the other side of the membrane walls; and, applying a reverse pressure differential across the membrane walls to cause flow of the cleaning solution through the wall from the other side of the membrane walls back to the one side of the membrane walls.

Abstract: A method of cleaning permeable, hollow membranes (6) in an arrangement of the type wherein a pressure differential is applied across the walls (15) of the permeable, hollow membranes (6) immersed in a liquid suspension, the liquid suspension being applied to the outer surface of the porous hollow membranes (6) to induce and sustain filtration through the membrane walls (15) wherein some of the liquid suspension passes through the walls (15) of the membranes (6) to be drawn off as clarified liquid or permeate from the hollow membrane lumens (7), and at least some of the solids are retained on or in the hollow membranes (6) or otherwise as suspended solids within the liquid surrounding the membranes (6).

Abstract: A projectile of non-lethal composition includes an outer casing that is substantially sealed prior to impact with a target both when the projectile is in a static condition and when the projectile is in a dynamic condition. A marking material is encapsulated within the outer casing prior to impact. The outer casing is configured to deform and unseal upon impact such that the marking material disperses forward via hydraulic action.