Patent application number | Description | Published |
20090143546 | Double Loop Technology - A method for controlling the injection of catalyst slurry in a polymerization reactor is described herein. The method includes the preparation of polyethylene with a solid catalyst and a hydrocarbon diluents. The method includes providing solid catalyst and a hydrocarbon diluent in one or more storage vessels such that a catalyst slurry is obtained in said vessel, transferring said catalyst slurry from said storage vessel to a mixing vessel wherein said catalyst slurry is diluted for obtaining a suitable concentration for use in a polymerization reaction, pumping said diluted catalyst slurry at a controlled flow rate from said mixing vessel to said polymerization reactor through one or more conduits, by means of a membrane pump provided in each of said conduits, and the membrane pump is controllable as a function of reactant concentration within the polymerization reactor. | 06-04-2009 |
20100016523 | Method for Making a Transition between Polymer Grades - The present invention relates to a method of transition between polymer grades in a polymerisation process comprising polymerising at least one monomer in at least a first reactor and a second reactor connected to each other in series, wherein the monomer feed in the first reactor is maintained essentially constant during the transition. | 01-21-2010 |
20100041825 | Method and System for Degassing Polymer Powder - The present invention relates to a method for degassing polymer powder comprising flushing the polymer powder in a first chamber with a first flow of flushing gas, transferring the polymer powder into a second chamber and flushing the polymer powder with a second flow of flushing gas in said second chamber. The present invention also relates to a system suitable for carrying out this method. | 02-18-2010 |
20110098421 | Process for Improving the Devolatilization of Polymer Slurry Produced in a Polymerization Reactor - The present invention relates to a process for improving the devolatilization of polymer slurry produced in an olefin polymerization reactor. The process is characterized in that it involves an adjustment of the temperature of the interior surface of the flash line for periodically transferring polymer slurry from the polymerization reactor to a downstream processing unit. In particular, in accordance with the present process, the temperature of the interior surface of the flash line is adjusted to a temperature which is equal to or higher than the softening temperature of the polymer passing through said flash line whereby said temperature is higher in a first half of the length of the flash line than in the remaining length of the flash line. | 04-28-2011 |
20130102741 | PROCESS FOR IMPROVING THE DEVOLATILIZATION OF POLYMER SLURRY PRODUCED IN A POLYMERIZATION REACTOR - The present invention relates to a process for improving the devolatilization of polymer slurry produced in an olefin polymerization reactor. The process is characterized in that it involves an adjustment of the temperature of the interior surface of the flash line for periodically transferring polymer slurry from the polymerization reactor to a downstream processing unit. In particular, in accordance with the present process, the temperature of the interior surface of the flash line is adjusted to a temperature which is equal to or higher than the softening temperature of the polymer passing through said flash line whereby said temperature is higher in a first half of the length of the flash line than in the remaining length of the flash line. | 04-25-2013 |
20130345374 | Double Loop Technology - A method for the copolymerization of ethylene and a C | 12-26-2013 |
20140048152 | Flash Line for Improving the Devolatilization of Polymer Slurry Produced in a Polymerization Reactor - The present invention relates to a process for improving the devolatilization of polymer slurry produced in an olefin polymerization reactor. The process is characterized in that it involves an adjustment of the temperature of the interior surface of the flash line for periodically transferring polymer slurry from the polymerization reactor to a downstream processing unit. In particular, in accordance with the present process, the temperature of the interior surface of the flash line is adjusted to a temperature which is equal to or higher than the softening temperature of the polymer passing through said flash line whereby said temperature is higher in a first half of the length of the flash line than in the remaining length of the flash line. | 02-20-2014 |
20140299208 | Double Loop Technology - The present invention relates to an apparatus and process for polymerizing olefins. One embodiment comprises polymerizing at least one monomer in a first loop reactor in the presence of a catalyst to produce a first polyolefin fraction. A portion of the first polyolefin fraction is transferred to a second loop reactor, connected in series with the first loop reactor. The process further comprises polymerizing in the second loop reactor at least one monomer in the presence of a catalyst to produce a second polyolefin fraction in addition to the first polyolefin fraction. The combination of the first and second polyolefin fractions can produce a polymer resin fluff having bimodal molecular weight distribution. | 10-09-2014 |
Patent application number | Description | Published |
20140066534 | POLYURETHANE FOAM AND METHOD FOR PRODUCING SAME - The invention relates to a method for producing a polyurethane foam, wherein a mixture having the following is discharged from a mixing head through a discharge line: A) a component reactive toward isocyanates; B) a surfactant component; C) a blowing agent component selected from the group comprising linear, branched, or cyclic C1 to C6 hydrocarbons, linear, branched, or cyclic C1 to C6 fluorocarbons, N2, O2, argon, and/or CO2, wherein the blowing agent C) is present in the supercritical or near-critical state; and D) a polyisocyanate component. The component A) has a hydroxyl value=100 mg KOH/g and =1000 mg KOH/g. The blowing agent component C) is present at least partially in the form of an emulsion, and means provided with an opening or several openings are arranged in the discharge line in order to increase the flow resistance during the discharge of the mixture comprising A), B), C), and D), wherein the cross-sectional area of the opening or the sum of the cross-sectional areas of all openings is =0.1% and =99.9% of the inner cross-sectional area of the discharge line. | 03-06-2014 |
20150051301 | METHOD FOR PRODUCING A HARD POLYURETHANE-POLYISOCYANURATE FOAMED MATERIAL - The present invention relates to a process for producing a rigid polyurethane-polyisocyanurate foam C, comprising the step of reacting (i) an isocyanate-terminated prepolymer B with (ii) an activator component A comprising at least one trimerisation catalyst A1 and at least one blowing agent A3 in a reaction mixture to form a foam, characterised in that—there is used an isocyanate-terminated prepolymer B obtained from a reaction of an isocyanate B1 having a mean isocyanate functionality of from ≧2.3 to ≦2.9 with a polyol component B2, and—the activator component A comprises water as the blowing agent A3 in an amount of from ≧5 wt. % to ≦50 wt. %,—the isocyanate index in the reaction mixture is in a range of from ≧400 to ≦500, and—the isocyanate content of the prepolymer B is in a range of from ≧21 wt. % to ≦30 wt. %, based on the total mass of the prepolymer B, and—wherein in the reaction of the prepolymer B and the activator component A a conversion contribution to polyisocyanurate of ≦75% is achieved. Rigid foams C so produced have good flame retarding properties while at the same time having good insulating properties and stability properties. The present invention relates further to a rigid polyisocyanurate foam C produced by the process according to the invention, to the use of such a rigid polyisocyanurate foam C in the production of heat-insulating structural components, and to a heat-insulating structural component comprising such a rigid polyurethane-polyisocyanurate foam. | 02-19-2015 |