Patent EA-000462-B1 (EA)
Title: Atomizer nozzle
Inventor: NEWTON DAVID
IPC: B01J8/00
Filed: 1996-11-14
Abstract: 1. A process for the introduction of liquid directly into a fluidized bed which comprises: (a) pressurizing the liquid; (b) feeding the pressurized liquid to a liquid inlet of an atomizing chamber of a nozzle; (c) preatomizing the liquid using a mechanical device positioned within the liquid inlet; (d) feeding assisting atomizing gas to a gas inlet of the atomizing chamber; (e) atomizing the preatomized liquid in the atomizing chamber using the assisting atomizing gas; and (f) discharging the atomized liquid as a spray into the fluidized bed through at least one outlet of the atomizing chamber. 2. A continuous gas fluidized bed process for the polymerization of olefin monomer selected from (a) ethylene, (b) propylene, (c) mixtures of ethylene and propylene and (d) one or more other alpha-olefins mixed with (a), (b) or (c), in a fluidized bed reactor by continuously recycling a gaseous stream comprising at least some of the ethylene and/or propylene through a fluidized bed in said reactor in the presence of a polymerization catalyst under reactive conditions, at least part of the said gaseous stream withdrawn from said reactor being cooled to a temperature at which liquid condenses out, separating at least part of the condensed liquid from the gaseous stream and introducing at least part of the separated liquid directly into the fluidized bed by: (a) pressurizing the liquid; (b) feeding the pressurized liquid to a liquid inlet of an atomizing chamber of a nozzle; (c) preatomizing the liquid using a mechanical device positioned within the liquid inlet; (d) feeding assisting atomizing gas to a gas inlet of the atomizing chamber; (e) atomizing the preatomized liquid in the atomizing chamber using the assisting atomizing gas; and (f) discharging the atomized liquid as a spray into the fluidized bed through at least one outlet of the atomizing chamber. 3. A process according to Claims 1 or 2 in which the atomizing chamber has 1 to 4 outlets. 4. A process according to any one of Claims 1 to 3 in which the atomizing chamber has a volume in the range 8.5 to 384 cm<3>. 5. A process according to any one of Claims 1 to 3 in which the nozzle has more than one outlet and each outlet for the atomized liquid has a separate atomizing chamber and mechanical device orientated in-line with the outlet. 6. A process according to any one of Claims 1 to 5 in which the mechanical device is selected from the group consisting of a swirl device, baffle plate, impingement device, fan device and an ultrasonic device. 7. A process according to any one of Claims 1 to 6 in which the outlets comprise circular holes, rectangular slots or elliptical slots. 8. A process according to any one of the preceding Claims in which each of the outlet(s) has a cross-sectional area in the range from 78.5 to 525.0 mm<2>. 9. A process according to any one of the preceding Claims in which a plurality of nozzles is arranged within the fluidized bed. 10. A process according to any one of Claims 2 to 9 in which the atomized liquid spray is introduced directly into the fluidized bed above the upper limit of the temperature gradient between the gaseous stream fed to the reactor and the remainder of the bed. 11. A process according to any one of Claims 2 to 10 in which the assisting atomizing gas is selected from the group consisting of an inert gas, make-up ethylene and recycle gas. 12. A process according to any one of Claims 2 to 11 in which liquid is introduced into the fluidized bed at a rate in the range 0.1 to 4.9 cubic meters of liquid per cubic meter of bed material per hour. 13. A process according to any one of Claims 2 to 12 in which the throughput of liquid through the nozzle is in the range 10 to 100 m<3>/h. 14. A process according to any one of Claims 2 to 13 in which the weight ratio of liquid: total gas introduced into the bed is in the range 1:100 to 1:1. 15. A process according to any one of Claims 2 to 14 in which the weight ratio of assisting atomizing gas to liquid introduced into the bed is in the range 0.5:1 to 5:1. 16. A process according to any one of Claims 2 to 15 in which the pressure of the assisting atomizing gas fed to the gas inlet of the atomizing chamber is in the range from 2 to 6 bar above the pressure of the fluidized bed. 17. A process according to any one of Claims 2 to 16 in which the pressure drop of liquid over the mechanical device of the nozzle is in the range 0.5 to 30 bar and the pressure drop of the assisting atomizing gas over the atomizing chamber and the outlet(s) of the nozzle is in the range 1 to 6 bar. 18. A process according to any one of Claims 2 to 17 in which the atomized liquid spray discharged from the outlets of the atomizing chamber has a horizontal momentum flux of at least 50x10<3> Kgxs<-1> m<-2> x mxs<-1> wherein the horizontal momentum flux is defined as the mass flow rate of liquid (kilogrammes per second) in the horizontal direction per unit cross-sectional area (square meters) of the outlet from which the atomized liquid spray emerges, multiplied by the horizontal component of the velocity (meters per second) of the atomized liquid spray. 19. A process according to any one of Claims 2 to 18 in which the atomized liquid spray is directed substantially horizontally into the bed. 20. A nozzle suitable for use for the injection of liquid into a fluidized bed said nozzle comprising: (a) an atomizing chamber; (b) a liquid inlet to the atomizing chamber; (c) a gas inlet to the atomizing chamber; and (d) at least one atomized liquid outlet from the chamber, characterized in that within the liquid inlet there is provided a mechanical device to preatomize the liquid. 21. A nozzle according to Claim 20 in which the atomizing chamber has a volume in the range 8.5 to 384 cm<3>. 22. A nozzle according to Claim 20 in which the nozzle has more than one outlet and each outlet for the atomized liquid has a separate atomizing chamber and mechanical device orientated in-line with the outlet. 23. A nozzle according to any one of Claims 20 to 22 in which the mechanical device is selected from the group consisting of a swirl device, baffle plate, impingement device, fan device and an ultrasonic device. 24. A nozzle according to any one of Claims 20 to 23 in which the outlets comprise circular holes, rectangular slots or elliptical slots. 25. A nozzle according to any one of Claims 20 to 24 in which each of the outlet(s) has a cross-sectional area in the range from 78.5 to 525.0 mm<2>.