Patent Application
20180250697
This disclosure relates to the field of spraying equipment and in particular a nozzle body apparatus for increasing the size of sprayed droplets to reduce spray drift.
There are many applications where it is necessary to spray a fluid material onto a target surface, often the ground. This application is notable for example in agriculture, horticulture and such things as golf course maintenance and pest control where chemicals are mixed with water and then sprayed on the ground, on plants growing from the ground, on bodies of water, and the like. Various fluids must also often be sprayed for example on roadways and in industrial applications to apply coatings and treatments to products passing by on a conveyor or the like.
Spraying is accomplished with sprayers, either self-propelled or towed units, and with aerial sprayers mounted on airplanes or helicopters. Such sprayers commonly comprise a tank of fluid, a pump for pressurizing and distributing the fluid to spray nozzles and means to control the fluid pressure. Sprayers typically have a plurality of nozzle bodies, each securing a spray nozzle tip, mounted on booms which swing in for transport and out for operation. Airplane mounted sprayers typically have a boom fixed to the wings.
The nozzle locations are spaced apart on a boom, perpendicular to the direction of travel, at a standard spacing distance which corresponds to the spray pattern of the nozzle tips. The same size nozzle tip is in operating position at each nozzle location, providing a consistent application rate across the width of the sprayer. Typically the nozzle tips are mounted in a nozzle body extending downward from the boom which carries the liquid agricultural products from the boom to the nozzle tips located in the bottom of the nozzle body. The nozzle body typically comprises an upper end connected to the boom and a channel extending downward to the nozzle tip mounted in the bottom end. A mesh strainer is commonly placed in the channel of the nozzle body between the nozzle tip and the boom. A typical strainer is provided by a hollow cylinder with wire mesh walls. Such a strainer and nozzle body is disclosed in U.S. Pat. No. 8,936,207 to Swan.
A problem with applying agricultural products such as herbicides is that even moderate air movement from wind, thermal conditions, and the like, can move the chemicals from the field being sprayed onto adjacent fields and, especially where the adjacent crop is of a different type and susceptible to the chemicals being sprayed, cause serious damage. Where fields are adjacent to urban or like otherwise occupied areas health issues also arise. This “drift” of chemicals is significantly affected by the size of the droplets being sprayed, with larger droplets being less susceptible to drift than smaller droplets. Conversely, it is generally the case that smaller droplets provide a better plant coverage than larger droplets, with corresponding increased efficacy in achieving the products aim, such as killing undesirable plants and weeds in the case of a herbicide.
Government regulations in some jurisdictions require a “label” on agricultural chemical products that indicates the conditions under which the product may be used, including the required application details such as limited environmental conditions, nozzles, nozzle droplet size classifications (droplet sizes), no spray zones, buffer zones, and other application details.
United States Published Patent Application Number 2008/0087745 of Pearson et al. discloses an air induction nozzle assembly for reducing the number fine small droplets dispensed from a sprayer nozzle. The assembly draws ambient air into the liquid flow stream for stabilizing the liquid prior to discharge from the nozzle.
U.S. Pat. No. 3,934,823 to Reed discloses angled tangential pre-orifices to impart a swirl to the swirl chamber which sprays into a second swirl chamber where the liquid appears to mix with air drawn into the chamber through the center of the hollow cone spray pattern dispensed from the nozzle tip which pattern comprises droplets of an increased size.
It is also known to provide a pre-orifice in the nozzle body above the nozzle tip. The pre-orifice device defines a hole which has a smaller flow rate than the nozzle tip and so controls the rate of flow and reduces the pressure at the nozzle tip so that larger droplets are dispensed from the nozzle tip. Wilger Inc. of Lexington, Tenn. makes and sells such pre-orifice devices that fit into the channel of the nozzle body between the nozzle tip and the boom, in the same location as the mesh strainer.
Similar problems occur in industrial applications where small droplets can fog and move off target onto machinery and surrounding areas.
The present disclosure provides a multiple pre-orifice apparatus for a sprayer nozzle body that overcomes problems in the prior art.
The present disclosure provides a multiple pre-orifice apparatus for a sprayer nozzle body where the nozzle body comprises an upper end connected to a liquid source to receive liquid to be sprayed, a nozzle tip releasably mounted at a lower end thereof, and a channel between the upper and lower ends of the nozzle body. The apparatus comprises a sleeve assembly comprising a sleeve closed at an upper portion thereof by a top orifice plate defining a top orifice, and closed at a lower portion thereof by a bottom orifice plate defining a bottom orifice such that a sleeve turbulence chamber is formed between the top and bottom orifice plates. The sleeve assembly is configured to be secured in the channel such that, when secured, a nozzle turbulence chamber is formed between the bottom orifice plate and the nozzle tip. An area of the top orifice is greater than an area of the bottom orifice, and an area of a flow opening in the nozzle tip is greater than the area of the top orifice.
The present disclosure provides a multiple pre-orifice apparatus that is readily installed in existing nozzle bodies used in agricultural spray equipment and where turbulence is generated in the sleeve and nozzle turbulence chambers. Providing multiple turbulence chambers and orifices increases the turbulence encountered by liquid passing therethrough and increases the occurrence of smaller drops amalgamating to form more desirable larger drops. Changing the configuration of the orifices and turbulence chambers along the width of a sprayer boom can increase the size of drops sprayed to a degree corresponding to the risk of drift out of the spray area at the particular location on the boom.
While the invention is claimed in the concluding portions hereof, preferred embodiments are provided in the accompanying detailed description which may be best understood in conjunction with the accompanying diagrams where like parts in each of the several diagrams are labeled with like numbers, and where:
The apparatus 1 comprises a sleeve assembly 15 comprising a sleeve 17 closed at a top end 17A thereof by a top orifice plate 19 defining a top orifice 21, and closed at a bottom end 17B thereof by a bottom orifice plate 23 defining a bottom orifice 25 such that a sleeve turbulence chamber 27 is formed between the top and bottom orifice plates 19, 23. In the apparatus 1 the top and bottom orifices 21, 25 are circular and are located in centers of the corresponding top and bottom orifice plates 19, 23. The sleeve assembly 15 is configured to be secured in the channel 9 such that, when secured, a nozzle turbulence chamber 29 is formed between the bottom orifice plate 23 and the nozzle tip 7. The illustrated top and bottom orifice plates 19, 23 are shown at the ends of the sleeve 17, but can also be placed in upper and lower portions of the sleeve to vary a length of the sleeve and nozzle turbulence chambers 27, 29.
The diameter and the corresponding area of the top orifice 21 is greater than the diameter and corresponding area of the bottom orifice 25. In many nozzle tips the flow opening 31 in the nozzle tip is not circular as are the top and bottom orifices 21, 25 but is shaped to provide the desired spray pattern. In any event the area of the flow opening 31 is greater than the area of the top orifice 21. With the smaller orifices 21, 25 the flow rate of liquid through the sleeve assembly 15 at any given pressure is less than the flow rate of liquid would be through the flow opening 31 in the nozzle tip 7 at the same pressure.
There is then a pressure drop between the liquid pressure at the sprayer boom 5 and the liquid pressure in the nozzle turbulence chamber 29. Liquid passing through the top orifice 21 sprays into the sleeve turbulence chamber 27 creating turbulence which causes fine drops to combine and thereby increases the size of the drops, and the liquid then sprays through the bottom orifice 25 into the nozzle turbulence chamber 29 again creating turbulence and again the drops further combine to again increase the size of the drops
The relative diameter of the two orifices 21, 25, the size of the flow opening 31 in the nozzle tip 7 and diameter and length of the sleeve and nozzle turbulence chambers 27, 29 can be adjusted to produce different levels of drift reduction. In an application where the bottom orifice plate 23 is mounted at the bottom of the sleeve 17, the length of the nozzle turbulence chamber 29 is dictated by the configuration of the particular nozzle body 3 and cap 11 however this can be adjusted as well by adjusting the position of the bottom orifice plate 23 with respect to the nozzle tip 7.
Also commonly the conventional nozzle body 3 will include a strainer assembly 33, schematically illustrated in
For example a common nozzle tip 7 used in agricultural spray applications is configured as schematically illustrated in
Thus for use with a common UR110-05 nozzle tip with a flow rate of 0.5 USgal/min at 40 psi the diameter of the top orifice 21 is 0.1094″ and the diameter of the bottom orifice 21 is 0.0625″. The length of the sleeve turbulence chamber 27 between the top and bottom orifices 21, 25 is about 0.85 inches for the UR110-05 nozzle tip. Depending on the sprayer tip used and the degree of droplet size increase the length of the sleeve turbulence chamber typically will be 0.125 inches to 1.0 inches, and preferably about 0.525 inches to 0.85 inches.
The relative lengths of the sleeve and nozzle turbulence chambers 27, 29 can be adjusted by moving the top and bottom orifice plates 19, 23.
In the sleeve assembly 115 of
Other configurations can be used to vary the length of the sleeve and nozzle turbulence chambers as desired.
The present disclosure provides a multiple pre-orifice apparatus 1 that is readily installed in existing nozzle bodies 3 used in agricultural spray equipment. Providing multiple chambers and orifices increases the turbulence encountered by liquid passing therethrough and increases the occurrence of smaller drops amalgamating to form more desirable drops. Changing the configuration of the orifices 21, 25 and chambers 27, 29 along the width of a sprayer boom can increase the size of drops sprayed to a degree corresponding to the risk of drift out of the spray area at the particular location on the boom.
The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous changes and modifications will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all such suitable changes or modifications in structure or operation which may be resorted to are intended to fall within the scope of the claimed invention.
