Gas and liquid contact apparatus – Contact devices – Injector type
Reexamination Certificate
2001-08-17
2002-05-28
Hopkins, Robert A. (Department: 1724)
Gas and liquid contact apparatus
Contact devices
Injector type
C261SDIG002, C261SDIG007, C426S474000
Reexamination Certificate
active
06394429
ABSTRACT:
FIELD OF THE INVENTION
The invention relates generally to the field of small particle formation and more specifically to fields where it is important to create gas bubbles which are very small and uniform in size.
BACKGROUND OF THE INVENTION
Monodispersed sprays of droplets of micrometric size have attracted the interest of scientist and engineers because of their potential applications in many fields of science and technology. Classifying a polydispersed aerosol (for example, by using a differential mobility analyzer, B. Y. Liu et al. (1974), “A Submicron Standard and the Primary Absolute Calibration of the Condensation Nuclei Counter,”
J. Coloid Interface Sci.
47:155-171 or breakup process of Rayleigh's type of a capillary microjet Lord Rayleigh (1879), “On the instability of Jets,”
Proc. London Math. Soc.
10:4-13, are the current methods to produce the monodispersed aerosols of micrometric droplets needed for such applications. The substantial loss of the aerosol sample during the classification process can severely limit the use of this technique for some applications. On the other hand, although in the capillary break up the size distribution of the droplets can be very narrow, the diameter of the droplets is determined by the jet diameter (approximately twice the jet diameter). Therefore, the generation and control of capillary microjets are essential to the production of sprays of micrometric droplets with very narrow size distribution.
Capillary microjets with diameters ranging from tens of nanometers to hundred of micrometers are successfully generated by employing high electrical fields (several kV) to form the well-known cone-jet electrospray. Theoretical and experimental results and numerical calculations on electrosprays can be obtained from M. Cloupean et al. (1989), “Electrostatic Spraying of Liquids in Cone Jet Mode,”
J. Electrostat
22:135-159, Fernández de la Mora et al. (1994), “The Current Transmitted through an Electrified Conical Meniscus,”
J. Fluid Mech.
260: 155-184 and Loscertales (1994), A. M. Gañán-Calvo et al. (1997), “Current and Droplet Size in the Electrospraying of Liquids: Scaling Laws,”
J. Aerosol Sci.
28:249-275, Hartman et al. (1997), “Electrohydrodynamic Atomization in the Cone-Jet Mode,” Paper presented at the ESF Workshop on Electrospray, Sevilla, Feb. 28-Mar. 1, 1997 among others [see also the papers contained in the Special Issue for Electrosprays (1994)]. In the electrospray technique the fluid to be atomized is slowly injected through a capillary electrified needle. For a certain range of values of the applied voltage and flow rate an almost conical meniscus is formed at the needle's exit from whose vertex a very thin, charged jet is issued.
The jet breaks up into a fine aerosol of high charged droplets characterized by a very narrow droplet size distribution. Alternatively, the use of purely mechanical means to produce capillary microjets is limited in most of applications for several reasons: the high-pressure values required to inject a fluid through a very narrow tube (typical diameters of the order of few micrometers) and the easy clogging of such narrow tubes due to impurities in the liquid.
The present invention provides a new technique for producing uniform sized monodispersion of gas bubbles based on a mechanical means which does not present the above inconveniences and can compete advantageously with electrospray atomizers. The jet diameters produced with this technique can be easily controlled and range from below one micrometer to several tens of micrometers.
SUMMARY OF THE INVENTION
The present invention provides aeration methods using spherical gas bubbles having a size on the order of 0.1 to 100 microns in size. A device of the invention for producing a monodispersion of bubbles includes a source of a stream of gas which is forced through a liquid held under pressure in a pressure chamber with an exit opening therein. The stream of gas surrounded by the liquid in the pressure chamber flows out of an exit orifice of the chamber into a liquid thereby creating a monodispersion of bubbles with substantially uniform diameter. The bubbles are small in size and produced with a relatively small amount of energy relative to comparable systems. Applications of the aeration technology range from oxygenating sewage with monodispersions of bubbles to oxygenation of water for fish maintenance.
REFERENCES:
patent: 3700170 (1972-10-01), Blanka et al.
patent: 3804255 (1974-04-01), Speece
patent: 3927152 (1975-12-01), Kyrias
patent: 4141055 (1979-02-01), Berry et al.
patent: 4162282 (1979-07-01), Fulwyler et al.
patent: 4347935 (1982-09-01), Merrill
patent: 4352789 (1982-10-01), Thiel
patent: 4363446 (1982-12-01), Jaeggle et al.
patent: 4444961 (1984-04-01), Timm
patent: 4603671 (1986-08-01), Yoshinaga et al.
patent: 4617898 (1986-10-01), Gayler
patent: 4628040 (1986-12-01), Green et al.
patent: 4662338 (1987-05-01), Itoh et al.
patent: 4717049 (1988-01-01), Green et al.
patent: 4781968 (1988-11-01), Kellerman
patent: 4917857 (1990-04-01), Jaeckel
patent: 5020498 (1991-06-01), Linder et al.
patent: 5077176 (1991-12-01), Baggio et al.
patent: 5087292 (1992-02-01), Garrido
patent: 5174247 (1992-12-01), Tosa et al.
patent: 5180465 (1993-01-01), Seki et al.
patent: 5194915 (1993-03-01), Gilby
patent: 5230850 (1993-07-01), Lewis
patent: 5364632 (1994-11-01), Benita et al.
patent: 5364838 (1994-11-01), Rubsamen
patent: 5372867 (1994-12-01), Hasegawa et al.
patent: 5397001 (1995-03-01), Yoon et al.
patent: 5404871 (1995-04-01), Goodman et al.
patent: 5458292 (1995-10-01), Hapeman
patent: 5522385 (1996-06-01), Lloyd et al.
patent: 5554646 (1996-09-01), Cook et al.
patent: 5597491 (1997-01-01), Winkler
patent: 5697341 (1997-12-01), Ausman et al.
patent: 5740794 (1998-04-01), Smith et al.
patent: 5775320 (1998-07-01), Patton et al.
patent: 5961895 (1999-10-01), Sanford
patent: 563807 (1975-07-01), None
patent: 4031262 (1992-04-01), None
patent: 0 249 186 (1987-12-01), None
patent: 0 250 164 (1987-12-01), None
patent: 2255291 (1992-11-01), None
patent: 2099078 (1992-12-01), None
patent: 59174561 (1984-10-01), None
patent: 03169331 (1991-07-01), None
patent: WO 90/05583 (1990-05-01), None
patent: WO 91/18682 (1991-12-01), None
patent: WO 94/11116 (1994-05-01), None
patent: WO 94/23129 (1994-10-01), None
patent: WO 95/23030 (1995-08-01), None
patent: WO 96/16326 (1996-05-01), None
patent: WO 97/43048 (1997-11-01), None
patent: WO 97/44080 (1997-11-01), None
Bowden et al., Science 276:233-5 (1997).
Brenn et al.,Chemical Engineering Science,52(2):237-244 (Jan. 1997) (Abstract).
Borchardt et al.,Chemistry&Biology,4(12):961-968 (1997).
Chin et al.,Trans. ASME J. Eng. Gas Turbines Power,106:639-644 (1983).
Cloupeau et al. (1989),J. Electrostat22:135-159.
Fernández de la Mora et al. (1994),J. Fluid Mech.260:155-184.
Forbes et al.,J. Austral. Math. Soc. Ser. B.,32:231-249 (1990).
Gañán-Calvo et al. (1997),J. Aerosol Sci.28:249-275.
Gauthier,Optics&Laser Technology,29(7):389-399 (Oct. 1997).
Hartman et al. (1997), “Electrohydrodynamic Atomization in the Cone-Jet Mode,” Paper presented at the ESF Workshop on Electrospray, Sevilla, Feb. 28-Mar. 1 1997 [see also the papers contained in the Special Issue for Electrosprays (1994)].
Huck et al.,Journal of American Chemical Societypp. 8267-8268 (1998).
Jasuja,ASME Paper82-GT-32 (1982).
Liu et al. (1974),J. Coloid Interface Sci.47:155-171.
Lorenzetto et al.,AIAA J.,15:1006-1010 (1977).
Nukiyama et al.,Trans. Soc. Mech. Eng. Jpn.,5:68-75 (1939).
Lord Rayleigh (1879),Proc. London Math. Soc.10:4-13.
Service et al., (1997),Science,277:1199-1200.
Singler et al.,Phys. Fluids A,5:1156-1166 (1993).
Tuck et al.,J. Austral. Math. Soc. Ser. B.,25:433-450 (1984).
Ünal,Metall. Trans. B.,20B:613-622 (1989).
Whitesides et al.,Science254:1312-9 (1991).
Wigg,J. Inst. Fuel,27:500-505 (1964).
Winfree et al.,Nature,394539-44 (1998).
Bozicevic Karl
Bozicevic Field & Francis LLP
Hopkins Robert A.
Universidad de Sevilla
LandOfFree
Device and method for fluid aeration via gas forced through... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Device and method for fluid aeration via gas forced through..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device and method for fluid aeration via gas forced through... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2899205