Abstract:
A novel Phillips catalyst for the copolymerization of ethylene with .alpha.-olefins, contains, as a catalytically active component, a finely divided, aluminum silicate-supported, phosphorus-containing chromium catalyst. This can be prepared by applying at least one organic phosphorus(III), (IV) and/or (V) compound and at least one chromium(III) compound which does not react with said phosphorus compounds under the reaction conditions used, in succcession in any order or simultaneously, to a finely divided aluminum silicate hydrogel or xerogel with formation of a catalyst intermediate and activating the catalyst intermediate at elevated temperatures in an oxidizing atmosphere, with the result that the chromium catalyst is formed. The novel Phillips catalyst gives ethylene/.alpha.-olefin copolymers in which the comonomers are more uniformly distributed over the copolymer chains than is the case with ethylene/.alpha.-olefin copolymers which have been prepared with the aid of conventional Phillips catalysts. Moldings which have been produced from the ethylene/.alpha.-olefin copolymers obtained in the novel procedure have a particularly high environmental stress cracking resistance and an excellent creep rupture strength.
Abstract:
A novel Phillips catalyst for the copolymerization of ethylene with .alpha.-olefins, contains, as a catalytically active component, a finely divided, aluminum silicate-supported, phosphorus-containing chromium catalyst. This can be prepared by applying at least one organic phosphorus(III), (IV) and/or (V) compound and at least one chromium(III) compound which does not react with said phosphorus compounds under the reaction conditions used, in succcession in any order or simultaneously, to a finely divided aluminum silicate hydrogel or xerogel with formation of a catalyst intermediate and activating the catalyst intermediate at elevated temperatures in an oxidizing atmosphere, with the result that the chromium catalyst is formed. The novel Phillips catalyst gives ethylene/.alpha.-olefin copolymers in which the comonomers are more uniformly distributed over the copolymer chains than is the case with ethylene/.alpha.-olefin copolymers which have been prepared with the aid of conventional Phillips catalysts. Moldings which have been produced from the ethylene/.alpha.-olefin copolymers obtained in the novel procedure have a particularly high environmental stress cracking resistance and an excellent creep rupture strength.
Abstract:
Ultrahigh molecular weight ethylene polymers are prepared in the gas phase in a thoroughly mixed bed of finely divided polymer by continuous introduction of the monomer into a polymerization system at 60.degree.-120.degree. C. and 5-60 bar in the presence of a reaction product of a titanium-containing catalyst and an antistat and in the presence of a monohydric or polyhydric alcohol.
Abstract:
A supported catalyst for ethene polymerization by Phillips catalysis is disclosed. The supported catalyst is prepared by (1) mixing a porous silicate in an inert, organic liquid to produce a silicate suspension, (2) providing an ester of phosphoric acid or phosphorous acid, (3) mixing an organic liquid, a chromium compound, and a trialkylaluminum compound to produce a chromium compound/aluminum compound and combining the silicate suspension, the phosphorus compound and the chromium compound/aluminum compound suspension. This resulting suspension is evaporated to dryness to form a catalyst intermediate. The catalyst intermediate is heated in nitrogen, then heated in an oxygen-containing atmosphere, and then heated again in nitrogen to produce an activated catalyst. The activated catalyst is suspended in an organic liquid and treated with an alkyl boron compound to produce the desired supported catalyst.
Abstract:
Ultrahigh molecular weight ethylene polymers are prepared in the gas phase in a thoroughly mixed bed of finely divided polymer by continuous introduction of the monomer into a polymerization system at 60.degree.-120.degree. C. and 5-60 bar in the presence of a reaction product of a titanium-containing catalyst and an antistat.
Abstract:
In a turbine for an exhaust gas turbocharger having a turbine housing with a turbine rotor rotatable supported therein and including spiral channels for directing exhaust gas onto the turbine wheel, at least one annular blocking element is supported between the spiral channels and the turbine wheel so as to be rotatable in the peripheral direction of the turbine wheel and additionally movable in the axial direction of the turbine wheel for a controlling the exhaust gas flow to the turbine wheel between impulse turbine mode when extended into the space between the turbine wheel and the spiral chamber and an accumulation made when retracted, with the gas flow through the turbine wheel or by-passing the turbine wheel being adjustable by rotation of the blocking element.
Abstract:
In an exhaust gas turbocharger for an internal combustion engine including an exhaust gas turbine in the exhaust line and a compressor in the intake tract of the internal combustion engine, and the exhaust gas turbine includes a gas inlet passage with a variable guide vane structure supported on one side of a support ring arranged in the inlet flow passage to the turbine wheel, the support ring is mounted in a floating manner such that the side thereof, which faces away form the guide vanes is exposed to the gas pressure in the inlet flow passage in order to bias the support ring toward the opposite inlet flow passage wall and spacer sleeves with expansion properties similar to those of the guide vanes are provided between the support ring and the opposite flow passage wall for delimiting the clearance between the guide vanes and the opposite flow passage wall.
Abstract:
A system for automatic charging pressure control using an exhaust gas turbocharger with a variably adjustable turbine cross-section and for automatic exhaust gas recirculation control in the case of an internal-combustion engine, particularly a diesel engine. An automatic control system has a first controller which has an output for the variation of the turbine cross-section of the exhaust gas turbocharger. The command variable for the automatic exhaust gas recirculation control in a first low load-rotational speed range is the air flow rate in the intake pipe. The command variable for the automatic charging pressure control in a second higher load-rotational speed range is the charging pressure in the intake pipe. For the automatic exhaust gas recirculation control, an exhaust gas recirculation pipe connects the exhaust gas pipe with the suction pipe. In the case of this system, for achieving the lowest possible pollutant emission while simultaneously minimizing fuel consumption, exhaust gas recirculation rates which are as precise as possible are defined in the lower load-rotational speed range, and a charging pressure which is as precise as possible is defined in the upper load-rotational speed range via a corresponding automatic control.
Abstract:
An apparatus for taking folded flat blanks out of a magazine and transferring them to a conveyor apparatus of a box-making machine is disposed between the vertically oriented magazine and the conveyor apparatus extending horizontally beneath it at some distance therefrom. The apparatus has three suction cups offset by 120.degree., on a star-shaped rotor which travel over a self-contained cycloid path (C) having four reversal points (F, G, H, I) and concave arcs between them. This cycloid path is generated by a revolving crank that rotatably supports the rotor with an eccentricity (E) and by a planetary gear associated with the crank, the sun gear of which is disposed coaxially with the axis of rotation of the crank, and the planet gear of which is firmly connected coaxially to the rotor; an intermediate gear is incorporated between the sun gear and the planet gear. The gear ratio of the planetary gear is 4:3 between the sun gear and the planet gear, and the spacing (D) of the suction cups from the shaft of the rotor is approximately three times the eccentricity of the crank. For erecting the foldable blank during the transfer, pressing fingers are associated with the suction cups and are pivoted by a control disk supported on the shaft of the rotor.
Abstract:
An apparatus for taking flat erectable blanks out of a magazine and transferring them to a conveyor apparatus has a rotor, on the circumference of which suction cups are distributed, offset uniformly. The rotor is rotatably supported as a planet part in a rotating planet carrier and upon revolving is additionally rotated about its shaft by a planetary gear. In this process the suction cups travel over a self-contained cycloid path (C) having four reversal points (F, G, H, I) and intervening concave arcs. For acting upon the articles, for instance pressing on a foldable box or rotating it about a transverse axis, a cam disk is rotatable supported on the shaft of the rotor and is hindered from rotating with the rotor by being coupled to a rocker arm supported in stationary fashion. A lever guided by a roller in the cam race acts upon a pivotable pressing prong or upon the rotatably supported suction cup.