Pumps – One fluid pumped by contact or entrainment with another – Jet
Patent
1992-12-01
1994-07-05
Bertsch, Richard A.
Pumps
One fluid pumped by contact or entrainment with another
Jet
417158, 417198, 239310, 239317, 239346, 222 85, B05B 726, F04F 544
Patent
active
053262280
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a method and apparatus for the metering and dispensing of an active ingredient. The invention is applicable to the dispensing of atomised sprays and finds particular use in the spraying of insecticides especially where large spaces such as warehouses and supermarkets are to be sprayed. However, the invention is equally applicable to the dispensing of room fresheners, fertilizers and any other active ingredients which are capable of being borne in an atomised mist. The invention can also be used to charge portable cylinders of pressurised fumigant, etc for manual dispersal.
EP-A-425 300 (published 2 May 1991) describes an apparatus for dispensing an active ingredient wherein the active ingredient is placed in a container into which a pressurised propellant is introduced from a propellant source. Part of the propellant flows direct from the propellant source to a dispensing outlet by means of a bypass. The rest of the propellant enters the active ingredient container and expands to adopt a liquid phase and a gaseous phase. The liquid phase serves to absorb the active ingredient whereas the gaseous phase serves to propel the active ingredient out of the apparatus through a dispensing outlet where further expansion takes place and the active ingredient is dispersed in a fog or mist. Flow restrictors create a pressure differential between the active ingredient cylinder outlet and the bypass portion so as to facilitate absorption of the active ingredient into the bypass propellant stream. It has now been found that the correct choice of pressure differential and the inclusion of a specially designed mixing chamber can improve the efficiency of the system.
Accordingly, a first aspect of the present invention provides an ejector for mixing a stream of liquefied gaseous propellant and a liquid stream containing active ingredient, the ejector comprising: a mixing chamber; a first ejector conduit for supplying the propellant, the first conduit opening into the mixing chamber via a main jet; a second conduit for supplying the active ingredient to the mixing chamber; an outlet port opening out of the chamber and located opposite the main jet; and a third conduit connecting the exit port to a dispensing outlet, the third conduit flaring from the outlet port to have a diameter larger than that of the outlet port.
A second aspect of the invention provides an apparatus for mixing an active ingredient and a liquefied gaseous propellant, comprising a concentrate container for the active ingredient, an ejector comprising an inlet jet for propellant and a mixing chamber, a first conduit connecting the ejector inlet jet to a source of propellant and a second conduit connecting the concentrate container to the mixing chamber, a third conduit connecting the mixing chamber to a dispensing outlet, and a fourth conduit connecting the first conduit to the concentrate container, characterised in that a means is provided for creating a pressure differential between the fluid in the portion of the first conduit opening into the mixing chamber and the fluid in the mixing chamber, the said pressure differential being (i) sufficient to draw substantially all the active ingredient from the concentrate container, (ii) less than that required to cause a cooling effect in the mixing chamber and (iii) less than that which would give rise to an erratic dispersion of the active ingredient from the dispensing outlet.
An "erratic" dispersion of mixture is one in which the mixture is delivered in a pulsing or non-uniform fashion. This has been found to cause icing up of the outlet nozzles, followed by the ice breaking off, a sudden rush of mixture, more icing up and so on.
The `cooling effect` in the mixing chamber results from the pressure differential between the propellant input stream and the mixing chamber. The actual temperature drop, for a given pressure differential, depends on the nature of the propellant and active ingredient. When used herein, the term `cooling effect` means a temperature drop of more than
REFERENCES:
patent: 2058901 (1936-10-01), McPherson
patent: 2901182 (1959-08-01), Cragg et al.
patent: 3165114 (1965-01-01), Garrett
patent: 3421738 (1969-01-01), Dulger
patent: 3784116 (1984-01-01), Buckman et al.
patent: 4099672 (1978-07-01), Sheahan et al.
patent: 4200206 (1980-04-01), Chase et al.
patent: 4247531 (1981-01-01), Hicks
patent: 5020689 (1991-06-01), Eitner, Jr. et al.
patent: 5085278 (1992-02-01), Keltner
patent: 5150822 (1992-09-01), Eitner, Jr. et al.
patent: 5213264 (1993-05-01), Styne
Armitage David A.
Peacock John
Bertsch Richard A.
McAndrews Roland G.
Roussel-Uclaf
LandOfFree
Liquid ejection mixing and dispensing apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Liquid ejection mixing and dispensing apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Liquid ejection mixing and dispensing apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-793054