Abstract: The present invention provides an injection nozzle for mixing an initiator with a process fluid. Then injection nozzle comprises a body comprising an inlet port, and outlet port, and an injector inlet; a process fluid flow passage; an initiator flow fluid passage; and a stylus. The process fluid flow passage comprises a constricting portion and an expanding portion to help improve transport and mixing. The injection nozzle is useful for injecting a fluid into another fluid at elevated temperatures and pressures, and for maximizing mixing of the fluids.

Abstract: An initiator injection nozzle for mixing an initiator with a process fluid, comprising: a body comprising an inlet port to receive the process fluid, an outlet port, and an injector inlet to receive initiator; a process fluid flow passage through which the process fluid traverses between the inlet port and outlet port along a central process flow axis, further comprising a constricting portion, a throat, and an expanding portion in that order, —an initiator fluid flow passage through which the initiator traverses between the injector inlet and injector outlet along an injector central vertical axis, where the initiator fluid flow passage intersects the process fluid flow passage in the constricting portion; a stylus at least partially containing the initiator fluid flow passage and further comprising a shaped injector tip forming the injector outlet of the initiator fluid flow passage; where the injector outlet is located in the constricting portion of the process fluid flow passage and upstream of the throat

Abstract: A tube reactor system containing a process fluid, comprising: at least one fresh feed source for supplying ethylene into a process fluid; a primary compressor for pressurizing the process fluid to reaction conditions in fluid communication with both the at least one fresh feed source and a recycle conduit; a reactor tube for converting a portion of the ethylene and optionally at least one comonomer within the process fluid into a low density ethylene-based polymer and a remaining portion of ethylene in fluid communication with the primary compressor; a high pressure separator for separating the low density ethylene-based polymer from the remaining portion of ethylene in fluid communication with the reactor tube; the recycle conduit in fluid communication with the high pressure separator for conveying the remaining portion of ethylene to the primary compressor; where the improvement comprises a reactor tube further comprising at least one initiator injection nozzle in fluid communication with an initiator s