Abstract: A dump tank for receiving congealable material vented from a chemical process, the dump tank having two access doors covering two access ports, both doors being openable for cleaning purposes so that congealable material vented into the tank can be pushed out of one access port from the other port.

Abstract: In a process for making solvent-spun cellulose fibre, cellulose is dissolved in aqueous N-methylmorpholine N-oxide to form a solution, said solution is passed through at least one pipe, the temperature in degrees Centigrade of said solution in the center of said pipe being controlled at 1000/(X+0.98.sqroot.D) and/or the temperature of said solution at the interior wall of said pipe being controlled at 1000/(Y+1.15.sqroot.D) where D represents the internal diameter of said pipe in inches, X represents a value equal to or greater than 5.0 and Y represents a value equal to or greater than 5.4, and said solution is subsequently extruded through a die to form filaments which are coagulated, washed with water to remove said solvent and then dried, thereby forming said solvent-spun cellulose fibre.

Abstract: A method for transporting a solution of cellulose in aqueous N-methylmorpholine N-oxide through a pipe, the temperature in degrees centigrade of said solution in the center of said pipe being controlled at 1000/(X+0.98 x.sqroot.D) and/or the temperature of said solution at the interior wall of said pipe being controlled at 1000/(Y+1.15 x.sqroot.D) where D represents the internal diameter of the pipe in inches, X represents a value equal to or greater than 5.0, and Y represents a value equal to or greater than 5.4.

Abstract: A safety system for relieving over pressure in a pipeline carrying a congealable material, in which the pipeline is provided with a bursting disc located in a spur of the pipeline, the disc being mounted in a holder so that the surface of the disc forms part of the wall of the pipeline so that material passing down the pipeline washes the surface of the disc and keeps its clean.