Abstract: An apparatus for separating entrained matter from a flowing fluid carrying the entrained matter includes a passage diverging at an angle of from 3 to about 20 degrees in the direction of flow of the fluid and at least one helical flight having the same twist direction throughout located with the passage and tapered to conform thereto. A straight cylindrical pipe is attached to the outlet end of the passage; the pipe contains a straight baffle interlocking to aboout 90 degrees with the helical flight. Opposed edges of the flight may be spaced from or in contact with the wall of the diverging passage.

Abstract: The efficiency of a rectifying zone for the recovery of diamine vapor from water vapor being separated from a reaction zone in which a polyamide-forming salt is being heated to form a prepolymer is improved by adding a dicarboxylic acid to the reflux water at the top of the rectifying zone.

Abstract: A flashing reactor wherein the initial single pipe carrying the ingredients within the flasher shell is connected within the shell to a flow splitter which in turn is connected to at least two other pipes arranged for parallel flow. In order to avoid an abrupt change in pressure and flow rate downstream from the splitter, the cross-sectional area of the branch pipes immediately adjacent the splitter is approximately equal to the cross-sectional area of the single pipe feeding of the splitter. The branch pipes are then increased in diameter until the combined cross-sectional area of the branch pipes is increased to up to twice the area of the single pipe feeding the splitter.

Abstract: A valve for adding ingredients to or sampling the fluid flowing through the valve includes an adjustable solid stem which can be extended through the flow path of a pipeline to form a seal with a seat positioned directly opposite the stem. An injection nozzle is fitted into the seat to permit addition of ingredients or sampling of the fluid when the stem is retracted from the seat. When the stem is seated, flow still occurs in the flow path.

Abstract: A process for preventing deposits when venting steam containing entrained polymer from high pressure reactors used for preparing nylon from dicarboxylic acid and diamine. The hot steam generated during condensation polymerization of the reactants is vented through a pressure-control valve at a rate which maintains a desired pressure in the reactor. Deposit of polymer in the valve or vent pipe after release of pressure is prevented by injecting water into the low pressure side of the valve or into the subsequent vent pipe. At least sufficient water is used to saturate the vented steam and to wet the walls of the vent pipe.