摘要:
Catalyst systems which are suitable for the polymerization of olefinically unsaturated hydrocarbons contain, as active components, A) an amidinato metal complex of the formula A ##STR1## where M is a metal from group IIIb, IVb, Vb or VIb of the Periodic Table of Elements or a metal from the lanthanide group, X is a negative leaving atom or a negative leaving group, and the radicals X may be identical or different if (n-m)>1, R.sup.1, R.sup.2 and R.sup.3 are each a C-organic or Si-organic radical, n is the valency of M in the metal complex A and m is from 1 to 5, with the proviso that n-m.gtoreq.0, and, B) an activator in a molar ratio of activator B to metal complex A of from 0.5:1 to 10,000:1.
摘要:
A large-scale coking reactor including a housing provided with a chamber and with outer and inner chamber frames, a displaceable outer door elastically compressed against the outer frame and formed with a respective elastic peripheral seal compressible against the frame and with an outer high temperature membrane interposed between the door and the seal and elastically pressed thereagainst to seal the door opening, a displaceable inner door spaced from the outer door and formed with an inner high temperature membrane interposed between the inner door and the inner frame to fit elastically the inner frame, the inner and outer doors being releasably interconnected upon displacing the outer door, so that the doors are mounted in the housing to be operatable either selectively or in combination with one another.
摘要:
A casing for holding electronic components and the like, is provided on each of its side walls facing away from one another with two fastening lugs which project laterally therefrom and are each provided with an opening for the passage of a screw, and which are associated with casing side edges corresponding to one another. The openings for the passage of a screw which are provided in fastening lugs lying opposite one another and associated with the same side wall of the casing are in each case free from overlap, in their projection, with the fastening lug lying opposite. The arrangement of the fastening lugs makes possible the installation of the casing in both right-hand and left-hand drive vehicles without being mounted with mirror inversion. This provides advantages, for example, when there is restricted space to accommodate the cable leading out of the casing.
摘要:
The arrangement includes three casting lines arranged in front of a finishing train. The casting line in the middle is in alignment with the finishing train. The thin slabs severed from the cast strands are conveyed to the finishing train with two ferries and which are combined longitudinal/transverse/longitudinal conveying systems. The thin slabs are conveyed by placing the two ferries alternatingly in alignment with two adjacent casting lines.
摘要:
To make hot rolled steel strap from strap like cast starting material cast pieces can be first cut from the solidfying casting after the casting process is completed. Then these cast pieces are guided to and stored in an oven where they are brought to and maintained at the rolling temperature. The cast pieces are fed in succession into the rolling mill. Then the cast pieces are stored there at the rolling temperature until the rolling process begins. A number of cast pieces are produced as raw products in our invention and stored until the rolling of these individual cast pieces starts. the casting is continuous and occurs also during the rolling operation. Because of the intermediate storage provided by the oven significant differences can exist between the casting time and the rolling time. Assembly and maintenance of the rolling mill, e.g. roll changing, can be performed in a pause of the roll cycle which includes the rolling time. If necessary the two pauses of two roll cycles are placed immediately in succession. The cast pieces formed during this time are fed to the oven and stored there. An apparatus for performing this process is also described.
摘要:
A drag-chain conveyor has a trough-shaped elongated passage a bottom wall of which is formed with one or more openings each bounded by a circumferentially extending marginal wall portion of stepped cross-section. A discharge chute is provided for each opening and extends downwardly from the bottom wall. A closure plate is provided for each opening and each plate is movable between a position in which it is withdrawn from the respective opening and a position in which it is located and closes the opening. The closure plate has a circumferentially extending bevelled edge face which sealingly engages the wall portion bounding the respective opening when the closure plate is in its closing position. A mounting arrangement mounts the closure plate for movement between the positions thereof.
摘要:
A process for preparing alkanols (I) selected from the group consisting of isopropanol and 2-butanol from the corresponding alkanes (II) selected from the group consisting of propane and n-butane, comprising the steps of: A) providing a starting gas stream a comprising the alkane (II); B) feeding the starting gas stream a comprising the alkane (II) into a dehydrogenation zone and subjecting the alkane (II) to a dehydrogenation to the alkene (III) to obtain a product gas stream b comprising the alkene (III) and unconverted alkane (II), with or without high boilers, steam, hydrogen and low boilers; C) at least compressing product gas stream b, optionally separating product gas stream b into an aqueous phase c1, a phase c2 comprising the alkene (III) and the alkane (II), with or without high boilers, and a gas phase c3 comprising hydrogen and low boilers; D) reacting product gas stream b or the phase c2 comprising alkene (III) and alkane (II) with an organic acid (IV) in an esterification zone to obtain a product mixture d comprising the corresponding alkyl ester (V) of the organic acid and the unconverted alkane (II); E) removing from product mixture d a gas stream e1 which comprises an alkane (II) and is recycled into the dehydrogenation zone if appropriate, and a product mixture e2 comprising the alkyl ester; F) reacting the product mixture e2 comprising the alkyl ester with water in an ester hydrolysis zone to give a product mixture f comprising the alkanol (I) and the organic acid (IV); G) removing the alkanol (I) and the organic acid (IV) from product mixture f and, if appropriate, recycling the organic acid into the esterification zone.
摘要:
The invention relates to a device for partitioning the plastic parisons to give at least one semifinished open-surface product (6), where the device encompasses at least one means of partitioning (3) the plastic parison and one means of drive (2). The means of drive may be composed of one, but preferably of two, driven rolls. It has been found that use of the device of the invention can reduce or prevent the production of creasing and irregularity at the margins, i.e. at the cut edges, of the partitioned parisons, i.e. of the resultant semifinished sheets.
摘要:
The invention relates to a process for preparing a catalyst for the polymerization of olefins, which comprises: a) preparation of a finely divided silica xerogel, b) loading of the xerogel with chromium from a solution of chromium trioxide or a chromium compound which is converted into chromium trioxide under the conditions of step c), and c) activation of the resulting product at from 400 to 1100° C. in a water-free gas stream comprising oxygen in a concentration of above 10% by volume, wherein a fluoride doping with a fluorinating agent is carried out in step b) or in step c). Furthermore, the invention relates to a catalyst for the polymerization of olefins which is obtainable by the process of the invention and to a process for the polymerization of olefins in which an olefin or an olefin mixture is polymerized in the presence of a catalyst according to the invention.
摘要:
The invention relates to a roll stand comprising a crown-variable-control (CVC) roll pair, preferably a CVC working roll pair and a back-up roll pair, which comprise a contact area (B cont) in which a horizontally active torque (M) acts that leads to a twisting of the rolls and thus to axial forces in the roll bearings. In order to keep the axial forces in the roll bearings as small as possible, the torque (M) is minimized by an appropriate CVC grinding.