Abstract: A process for the discontinuous production of granules from polycondensation polymers by precondensation of an oligomer at 5 to 400 mbar and subsequent polycondensation in a stirring reactor and subsequent granulation. In the vicinity of the outlet port, the density of the entraining surfaces lies between 1 and 8 m2 per m3 reactor space and constantly increases with increasing distance from the discharge region. Inside the reactor, there is a viscosity gradient between the region most remote from the discharge port and the zone of the discharge port. The thermal decomposition of the polymer melt flowing out of the reactor is compensated during granulation. The stirring reactor with horizontal longitudinal axis approximately has the shape of a single or double truncated cone. The reactor has rotatable, vertical product entraining surfaces and stationary scrapers between the same.

Abstract: Method of cleaning valves or lines through which hydrolysable polymers are transported at the operating temperature, in which, after the polymer stream has been shut off and the polymer has been evacuated as far as possible, steam is passed through the valves or lines to be cleaned while the operating temperature is maintained at plus/minus 10° C., with the steam being introduced via hydrolysis valves set in the wall of the valve housing or the lines and discharged via emptying apertures.

Abstract: An alternating distributor for high-viscosity liquids consisting of a product line I (2) which discharges in a central distribution chamber (1) having no surfaces and edges running perpendicularly to the flow of the product and for this purpose two product valves (3) in a Y-shaped arrangement each having a product line II (6) and optionally an auxiliary valve, characterized in that the valve blocks (8) of the product valves (3) have a mushroom-shaped displacer headpiece (11, 12) which when the valve is closed is positioned in the distribution chamber (1) and when the valve is open is positioned at the level of product line II (6).

Abstract: A process for the discontinuous production of granules from polycondensation polymers by precondensation of an oligomer at 5 to 400 mbar and subsequent polycondensation in a stirring reactor and subsequent granulation. In the vicinity of the outlet port, the density of the entraining surfaces lies between 1 and 8 m2 per m3 reactor space and constantly increases with increasing distance from the discharge region. Inside the reactor, there is a viscosity gradient between the region most remote from the discharge port and the zone of the discharge port. The thermal decomposition of the polymer melt flowing out of the reactor is compensated during granulation.

Abstract: The present invention comprises a multiway valve for fluids, consisting of an inlet line (1), a connector housing (9), basic valve bodies (2, 3) and additional valve bodies (25, 26, 26') branching off from the connector housing (9), with each of the valve bodies (2, 3, 25, 26, 26') having a valve housing (10) designed as a guide cylinder with a lateral discharge outlet (4) opening into the respective outlet line (5), with a valve spindle (13, 13a) movable in the axial direction within the guide cylinder with a valve head (12, 12a) engaging in a valve seat (6) in the connector housing (9) in the closed position of the respective valve body, as well as the use of this multiway valve.The basic valve bodies (2, 3) have a valve head lantern (17, 18) in the form of a straight cylinder (17) with an attached, straight cylinder (18) cropped at an inclined angle.

Abstract: Distributor for viscous fluids with a feed line and multiple discharge valves and lines, each comprising a valve housing eccentrically enlarged opposite the discharge line and a valve piston with a hat-shaped valve head surmounted by a mushroom-shaped attachment. The valve piston may be positioned with respect to the eccentrically-enlarged portion of said housing to control the flow through the gap between the valve head attachment and the enlarged portion as compared with the flow through the gap between the attachment and the housing wall on the side adjacent the discharge line.

Abstract: Continuous multistep, economical, energy-saving process for making polybutylene terephthalate in which the butanediol-1,4 used to transesterify dimethyl terephthalate is supplied from the condensed vapors volatilized during the precondensation and polycondensation steps of the process. These vapors, which contain low-soluble esters of terephthalic acid as well as butanediol, are condensed by contact with fresh butanediol, and volatilized butanediol containing the esters is recycled to the initial transesterification stage for reaction with dimethyl terephthalate. No additional butanediol is required for the reaction.