Abstract: An apparatus to improve the hydrodynamics in an underwater pelletizer, without the need of any modification of the current design or geometry of the pelletizer. The apparatus according to the present invention is designed under specific conditions and parameters, that improve the hydrodynamics in an underwater pelletizer, working as a diffuser. The present invention is additionally related to a system for improving hydrodynamics in an underwater pelletizer.

Abstract: Described is a fluidic seal apparatus for continuously injecting a sealing gas into a bottom section of a gas-solids separation chamber. The fluidic seal apparatus includes an external section, a feed tube in fluid communication with a sealing gas supply, and an internal section. The external section connects the sealing gas supply to the internal section. The internal section includes gas distribution nozzles for distributing the sealing gas inside the bottom section of the gas-solids separation chamber. An internal chamber between the internal section and the external section is pressurized by the sealing gas.

Abstract: A process for polymerization of vinyl chloride may include contacting vinyl chloride, demineralized water, at least one stabilizer agent, at least one dispersing agent, an initiator and optionally one or more comonomers; continuously feeding the vinyl chloride, demineralized water, at least one stabilizer agent, at least one dispersing agent, an initiator and optionally one or more comonomers into a tubular reactor having a length of at least 20 times an internal diameter of the tubular reactor; and continuously polymerizing the vinyl chloride, and optionally the one or more comonomers.

Abstract: A process for propylene preliminary polymerization in liquid phase that occurs in a continuous preliminary polymerization reactor may include feeding a propylene monomer and a Ziegler-Natta catalyst system having (a) a pro-catalyst having an internal electron donor comprising a substituted phenylene aromatic diester, (b) a catalyst activator and optionally (c) an external donor, into the continuous preliminary polymerization reactor, wherein the feeding is carried out without pre-contact of the pro-catalyst with the catalyst activator, and also without pre-contact of the catalyst activator with the propylene monomer before entering the continuous preliminary polymerization reactor.