Patent Application
20090078795
The present disclosure relates to liquid atomizers for use in agriculture.
Such liquid atomizers, which may also be referred to as foggers, sprayers, mist devices, humidifiers, etc., emit a fine mist of liquid. This fine mist may be achieved by guiding a liquid jet through a vortex path that causes the jet to swirl and exit the atomizer as a spray. These atomizers may be used for conditioning the environment by increasing humidity such as in a greenhouse.
U.S. Pat. No. 6,983,896, the disclosure of which is incorporated herein by reference, describes an atomizer with a vortex generating member that is fitted with an R-like vortex generating paths. Water flowing through the atomizer is forced to spin in the R-like path and exit as a fine spray of atomized liquid via a narrow outlet after it is swirled.
The following embodiment and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope.
In an embodiment, a liquid atomizer comprises at least one canal, a swirl chamber and an outlet that are formed therein, the canal being in fluid communication via the chamber with the outlet and the outlet opening out of the atomizer, wherein at least a section of the canal extends along a straight line and tangentially opens into the chamber to thereby form tangential direction and velocity to liquid jets entering the chamber.
In some embodiments, the chamber comprises a cylindrical portion into which the section of the canal opens and a coned portion, the cylindrical portion extending down towards the coned portion and the coned portion tapering down towards the outlet. Opening out of the canal sections into the cylindrical portion assists forming the liquid jets exiting the canals into a uniform flow.
In some embodiments, the canal has a canal face and an imaginary line included in the canal face and parallel to the straight line tangentially meets a periphery of the cylindrical portion.
In some embodiments, the section of the canal is a closed canal. This closed section may be formed by a part of the atomizer that abuts the open canals to form a ceiling or by forming a closed canal that passes through a portion of the atomizer. In the event that the canals are closed by a ceiling it is preferable that the part forming the ceiling is made of non-metal material with sealing properties.
In some embodiments, the coned portion of the chamber has a cone head angle α greater than or equal to 60 degrees and smaller than or equal to 135 degrees. Other angle values may, inter alia, impair optimal tangential velocity in the swirl chamber and decrease the spray angle exiting the outlet.
In addition to the exemplary aspects and embodiment described above, further aspects and embodiments will become apparent by reference to the figures and by study of the following detailed descriptions.
Exemplary embodiments are illustrated in referenced figures. It is intended that the embodiments and figures disclosed herein are to be considered illustrative, rather than restrictive. The disclosure, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying figures, in which:
It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated within the figures to indicate like elements.
Attention is first drawn to
The atomizer 10 has a longitudinal axis X defining opposing top and bottom directions therealong. It should be noted that directional terms appearing throughout the specification and claims, e.g. “top”, “bottom”, etc., (and derivatives thereof) are for illustrative purposes only, and are not intended to limit the scope of the appended claims. In addition it is noted that the directional terms “bottom”, “down”, “below” and “lower” (and derivatives thereof) define identical directions and the directional terms “top”, “up”, “above” (and derivatives thereof) define identical directions.
Attention is additionally drawn to
An axially extending main channel 34 and two minor channels 36 are formed in the bushing 14. The main channel 34 is closed at a bottom end and opens out to an upper end of the bushing 14. The minor channels 36 communicate with the main channel 34 and extend laterally to open out at opposing sides of the periphery of the shank 22.
The housing 16 has an axially extending cavity 38 having an upper portion 40, a lower portion 44 and a middle portion 42 therebetween. The upper and middle portions 40, 42 are cylindrical and coaxial and the middle portion 42 has a smaller diameter than the upper portion 40. The lower portion 44 (best seen in
Attention is additionally drawn to
The swirl chamber 48 opens out to the inlet 46 at the floor 52 and has an upper peripheral barrel face 60 and a lower peripheral cone face 62 (best seen in
The housing 16 has two canals 64 symmetrically distributed about the axis X that are formed therein (best seen in
Attention is drawn back to
Attention is additionally drawn to
The inventor performed studies of the efficiency of an atomizer 10 in accordance with the present disclosure. The studies indicate that when at least some of the parameters h, b, R, y, H, Lo and Do comply with the following relationships, an atomizer 10 in accordance with the present disclosure emits a fine liquid spray. Optionally, under liquid pressure of about 0.4 MPa an embodiment of the atomizer 10 emits a spray with liquid particles having a Sauter Mean Diameter (SMD) optionally smaller than 80 μm and preferably smaller than 60 μm. It is noted that some of the following relations are dependant upon each other.
For optimal tangential velocity in the swirl chamber 48, the angle α is optionally within the range of 60°<α<135° and the relative length of the outlet 50 is optionally within the range of
The relative length of the closed canal sections 74 is optionally
for the liquid entering the swirl chamber 48 to acquire optimal tangential direction and velocity. The relation between the width and height of each closed canal section 74 is optionally
to provide an optimal inlet area into the swirl chamber 48. The relation between the total inlet areas into the swirl chamber 48 and the total outlet area out of the swirl chamber 48 is optionally
(wherein N is the number of canals and r=Do/2). The relation between the heights of the swirl chamber's barrel face 60 and the canals 64 is optionally
And finally, to minimize hydraulic losses in the swirl chamber 48 the following relation should optionally be obtained
(wherein N is the number of canals and r=Do/2).
By way of a numerical example, an atomizer 10 in accordance with an embodiment of the present disclosure with two canals has the following dimensions. h=0.4 mm, b=0.4 mm, R=1.7 mm, y=0.96 mm, H=0.6 mm, Lo=0.5 mm and Do=0.53 mm.
Attention is drawn to
In the description and claims of the present application, each of the verbs, “comprise” “include” and “have”, and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of members, components, elements or parts of the subject or subjects of the verb.
Although the present embodiment has been described to a certain degree of particularity, it should be understood that various alterations and modifications could be made without departing from the scope of the disclosure as hereinafter claimed.
