Abstract: A catalyst slurry for a polymerization reactor can be prepared in a mixing tank and the catalyst slurry fed to one or more storage tanks. The storage tanks can include agitators so that the catalyst slurry is maintained at an essentially homogeneous solids-to-liquid ratio. From the storage tank(s), the catalyst slurry can be pumped to the polymerization reactor along a fluid passage having a flow meter. The flow of the catalyst slurry can be continuous and/or adjusted based on a measured parameter. The catalyst slurry may be continuously and reliability fed to the polymerization reactor.

Abstract: An improved polymerization process includes withdrawing a portion of a fluid slurry through a plurality of active continuous take off mechanisms, monitoring the pressure of feed material fed to the reactor, and adjusting the continuous take off mechanisms in response to the monitored feed line pressure.

Abstract: Polymer solids are maintained in an intermediate pressure zone for a desired polymer solids residence time and then transferred to a purge zone or other lower pressure zone. An increase in the polymer solids residence time in the intermediate pressure zone allows more diluent to flash or separate, thereby avoiding or reducing the need for a low pressure flash zone. A fluff chamber may be disposed between the intermediate pressure zone and a lower pressure zone transporter tank may be used to transport polymer solids after the intermediate pressure zone.

Abstract: A recycling and recovery system and process comprising a flash gas separator that receives a slurry comprising liquid medium and solid polymer particles. The flash gas separator separates the diluent from the solid polymer particles as a vapor stream comprising at least diluent and heavies. A line receives the vapor stream from the flash gas separator. The line leads to a heavies removal system that yields a liquid that is relatively concentrated in heavies and a diluent vapor that is relatively free of heavies. The liquid is passed to a heavies column, while the diluent vapor is passed to a diluent recycle chamber and then recycled to a slurry polymerization reactor without additional treatment to remove heavies.

Abstract: A slurry polymerization process wherein olefin monomer is fed to a continuous loop reactor at two or more points, allowing operation at higher and steadier monomer concentrations in the circulating slurry. A loop reactor apparatus has two or more monomer feeds and may have two or more catalyst feeds and/or two or more product take-offs, and each feed may have its own associated control scheme.

Abstract: A polymerization loop reactor including a loop reaction zone, a continuous takeoff, and a fluid slurry disposed in the reaction zone. A generally cylindrical wall defines the loop reaction zone. The length of the loop reaction zone and the nominal outside diameter of the generally cylindrical wall define a length/diameter ratio greater than 250. The reactor can be charged with a fluid slurry including an olefin monomer reactant, solid olefin polymer particles, and a liquid diluent. The concentration of the solid olefin polymer particles in the slurry can be greater than 40 weight percent based on the weight of polymer particles and the weight of liquid diluent. Also disclosed is a polymerization process carried out by polymerizing, in the loop reaction zone of a reactor as defined above, at least one olefin monomer in a liquid diluent to produce a fluid slurry as defined above.

Abstract: A process and apparatus for passing a polymerization effluent, comprising solid polymer, unreacted monomer, diluent and minor amounts of contaminants, to a high pressure flash where most of the fluid components are flashed and wherein a slip stream comprising diluent and minor amounts of monomer is separated from the bulk of the flashed fluid components. The slip stream is subjected to olefin removal to give an essentially olefin-free stream for recycle to a catalyst mud preparation area. The bulk of the flashed fluid components are recycled directly back to the polymerization zone without expensive olefin removal, although treatment to remove other contaminants can optionally be performed. The polymer and entrained fluid is passed to a low pressure flash zone where the fluids are flashed off, compressed and joined with the flash from the high pressure flash tank.

Abstract: A process and apparatus for passing a polymerization effluent, comprising solid polymer, unreacted monomer, diluent and minor amounts of contaminants, to a high pressure flash where most of the fluid components are flashed and wherein a slip stream comprising diluent and minor amounts of monomer is separated from the bulk of the flashed fluid components. The slip stream is subjected to olefin removal to give an essentially olefin-free stream for recycle to a catalyst mud preparation area. The bulk of the flashed fluid components are recycled directly back to the polymerization zone without expensive olefin removal, although treatment to remove other contaminants can optionally be performed. The polymer and entrained fluid is passed to a low pressure flash zone where the fluids are flashed off, compressed and joined with the flash from the high pressure flash tank.

Abstract: A process and apparatus for passing a polymerization effluent, comprising solid polymer, unreacted monomer, diluent and minor amounts of contaminants, to a high pressure flash where most of the fluid components are flashed and wherein a slip stream comprising diluent and minor amounts of monomer is separated from the bulk of the flashed fluid components. The slip stream is subjected to olefin removal to give an essentially olefin-free stream for recycle to a catalyst mud preparation area. The bulk of the flashed fluid components are recycled directly back to the polymerization zone without expensive olefin removal, although treatment to remove other contaminants can optionally be performed. The polymer and entrained fluid is passed to a low pressure flash zone where the fluids are flashed off, compressed and joined with the flash from the high pressure flash tank.

Abstract: A method for determining myoglobin oxygen fractional saturation in vivo in muscle tissue and intracellular oxygen tension (pO.sub.2), typically in the presence of hemoglobin, is provided. The method comprises measuring the absorption spectrum of the tissue using spectrographic equipment known to the art, including equipment for non-invasively taking spectroscopic measurements of tissue, or adaptations of such equipment to provide the preferred measurements described herein, or using spectrographic equipment specifically designed as described herein for use in non-invasive measurements of reflectance spectra. The measured spectrum is corrected for light scattering effects, such as by taking the second derivative of the data, or by using other means which are known to the art.

Abstract: The temperature of an infrared radiation scattering medium which contains water, for example, biological tissue and paper, cement and clay substrates, is determined by exposing the medium to infrared radiation, measuring the reflected radiation scattered by the medium, comparing the reflected radiation with calibrated values, and evaluating the temperature of the medium from the comparison; the technique provides a means of non-invasive determination of temperature in biological tissue which has utility in medical diagnosis.

Abstract: In withdrawing a reaction slurry from a polymerization reactor wherein solid particles in the slurry must be maintained in solution to prevent solidification, a redundant effluent line is provided to remove the slurry in the event the primary line becomes plugged. In use the primary and redundant lines are controlled in different manners such that a v-notch ball valve in the primary line is manipulated continuously to remove effluent while maintaining stable reactor conditions, and a control valve in the redundant line is manipulated intermittently as a backup for the primary control valve.

Abstract: In withdrawing a reaction slurry from a polymerization reactor wherein solid particles in the slurry must be maintained in solution to prevent solidification, a redundant effluent line is provided to remove the slurry in the event the primary line becomes plugged. In use the primary and redundant lines are controlled in different manners such that a v-notch ball valve in the primary line is manipulated continuously to remove effluent while maintaining stable reactor conditions, and a control valve in the redundant line is manipulated intermittently as a backup for the primary control valve.