Abstract: An apparatus for processing high viscosity materials consisting of a heatable, horizontal vessel with a product inlet on the one end and a product outlet on the other end and, parallel to the axis of the vessel, a heatable rotating hollow shaft, supporting a plurality of heatable stirrer elements, and between these stirrer elements, fixed to the wall of the vessel, stationary baffle and scraping elements of different configurations.Each stirrer element comprises one to four stirrer wings, each with two hollow spokes and a peripheral, hollow ring-segment connecting the spokes, and fixed to the peripheral end of these ring-segment connections trailing product dragging blades.

Abstract: Melt spinning method for the production of pre-oriented low-crystalline synthetic filaments which are distinguished by a high degree of uniformity and by the ability of being worked at high speeds in a friction-draw texturing process, according to which method the damping ratio of the spinning filament between the point of solidification and the winding unit, defined as the ratio of the fluctuation range of the filament tension at the beginning and at the end of the above-defined filament path is <0.10, and a driven roller with a freely rotating additional small roller in multiple wrap-around contact is utilized as the draw-off roller system.

Abstract: A process for the production of high-quality carpet yarn from PBT having an intrinsic viscosity of 0.9 to 1.2 comprising an integrated spinning-draw texturing process, employing a transport speed to the texturing unit of at least 1,800 m/min.

Abstract: A process and apparatus for dehydrogenating alkanes such as iso-butane comprises contacting the alkane in admixture with steam under dehydrogenation conditions with a dehydrogenation catalyst. The catalyst is substantially free of Group VIII metals of Atomic Number 27 and higher. The catalyst is provided in a heated tubular reactor which preferably contains groups of tubes mounted in a furnace each group of tubes having a common header, to enable continuous dehydrogenation, while permitting catalyst reactivation.

Abstract: A spinning manifold for melt-spinning synthetic high polymers is disclosed. The manifold has an elongated hollow body with cavities for the conduction of a heating medium, such as diphenyl, and a vertical nozzle shaft having heatable members placed between serially arranged and dismountable nozzle blocks such that the side walls of the heatable members are in heat exchange with adjacent nozzle blocks. These heatable members are displaceably mounted within the nozzle shaft. The pump shaft of the spinning manifold may also have additional heatable members placed between the pumping units. The same heating medium that flows through the cavities of the spinning manifold is placed within the heatable members.

Abstract: An improved process and apparatus for the melt-spinning of synthetic polymers are disclosed. The process and apparatus are preferably adapted to polymers such as polyamide 6, polyamide 66, polyester and their copolymers. The polymers are melt-spun in a spinneret and the resulting filaments are withdrawn at a speed between 600 and 6000 meters/min. The distance between the uppermost blow point of the cooling zone and the spinneret surface is selected so that the distance is within a range, the upper limit of which is defined by the relation B and the lower limit is defined by one of the relations A.sub.1 or A.sub.2 or A.sub.3 as follows:B=48.2 (log v)-109 (mm)A.sub.1 =34.4 (log v)-71 (mm)A.sub.2 =-32 (log v-3.356).sup.2 +34 (mm)A.sub.3 =-44 (log v-3.221).sup.2 +32 (mm),where v is the spinning withdrawal speed in meters/min.

Abstract: Production of spinnable polyhexamethylene adipamide of high molecular weight from adiponitrile, hexamethylene diamine, water and additives, preferably continuously in a reaction cascade and in a finisher as the final stage, catalytically accelerated by catalysts as disclosed.It has now been discovered that polyamides can be produced from dinitriles, diamines and excess water in the presence of catalysts selected from the group consisting of: (1) oxygen-containing phosphorous compounds; (2) oxygen-containing boron compounds; (3) acidic oxygen-containing sulfur compounds; and (4) hydrogen halide and ammonium or ammonium alkyl salt thereof.

Abstract: A process is provided for the continuous separation of slightly volatile components from a crude phthalic acid anhydride wherein a portion of the crude phthalic acid anhydride is compressed and heated before being reintroduced into a flash evaporator.

Abstract: An improved process for the spin-drawing of high-tenacity, technical-grade yarns is disclosed. The process produces yarns of high industrial quality having a low break elongation and low reference elongation, or a low heat shrinkage and low reference elongation. The process is especially suitable for yarns of polyamide and polyester.

Abstract: In a reactor housing for conducting the catalytic oxidation of gaseous sulfur compounds, a plurality of empty tubes are arranged in an outer zone of the housing for having incoming gas to be reacted flow therethrough. Larger catalyst-filled tubes are arranged in an intermediate zone for having the gas flow therethrough after flowing through the empty tubes for performing the catalytic oxidation in the larger catalyst-filled tubes. An inner chamber includes an axial-flow pump arranged therein and is in communication with the outer and intermediate zones in such a way that a heat-transfer agent is caused to flow cross-currently into and out of the outer zone, intermediate zone and inner chamber for contacting the empty tubes and catalyst-filled tubes.

Abstract: The process and apparatus described seeks to prevent NO.sub.x emissions after an emergency shutdown in a process for manufacturing nitric acid by catalytic combustion of ammonia, compression of the nitrous combustion gases and subsequent absorption. Immediately on shutdown the intake nitrous gas supply to the compressor is interrupted, the residual intake side nitrous gases are conveyed to the delivery side, the delivery side gas volume is shut off, the gas on the delivery side is expanded to the intake side and then exhausted into a vacuum system. Subsequently the acid charged with NO.sub.x in the absorption stages is drawn off, degassed acid is circulated through the absorption stages until equilibrium is established, the pressure of the shutoff section is released and cooled acid is admitted to the absorption stages.