摘要:
In a gas phase olefin polymerization using a transition metal compound/aluminum alkyl catalyst system, polymerization can be terminated rapidly by injecting an amount of carbon oxide and then restarting efficiently by addition of an amount of aluminum alkyl.
摘要:
This invention relates to an apparatus and process for feeding powder or dry solids catalyst into a flowing liquid stream. More particularly, the invention includes an apparatus which includes a novel purging device and means for isolating a metering means from a liquid stream, and process for injecting finely divided flowable powder or catalyst into a flowing liquid stream, which in turn is fed into a reactor utilized for the production of polypropylene or polyolefins.
摘要:
The process and the system are used for carrying out the quench-cooled, vapor-phase polymerization of olefin monomer in a horizontally disposed reactor vessel which comprises contacting olefin monomer, or a mixture of olefin monomers, with a polymerization catalyst system in the presence of hydrogen in the reactor vessel to form a polymer product. The improvement comprises introducing a titanium-containing catalyst component of the catalyst system into the top side of the reactor vessel at a point adjacent to the upstream end of the reactor vessel and introducing a cocatalyst plus modifer component of the catalyst system into the top side of the reactor vessel at a distance, downstream of the point of introduction of the titanium-containing catalyst component, which is equal to 25% of the inside diameter of the reactor vessel.
摘要:
A sandwich type acoustical absorbing panel for use adjacent to high speed gas flow areas in and around the engines of high speed aircraft. The panel in one embodiment comprises an imperforate facing sheet including having upright side and end walls, the inner volume of the panel and upright side and end walls are divided by means of partitions into a plurality of individual cavities or cells, each of the plurality of individual cavities or cells are filled with a bulk absorber material having many small torturous air passages, such as, open celled foam, fiberglass, felts or the like, the bulk absorber filling each cavity or cell is encapsulated in a membrane of thin limp material for preventing bulk absorber contamination and a perforated sheet overlay for attaching to the side, end walls and partitions for containing the bulk absorber within the cavities or cells.