WO2019094677A1

WO2019094677A1 - Electrostatically charged spray device with ultrasonic atomization

Info

Publication number: WO2019094677A1
Application number: PCT/US2018/059958
Authority: WO
Inventors: David C. Huffman; Thomas E. Ackerman; Michel R. Thenin; Lyndon John A. WEE SIT; Donald Weinstein
Original assignee: Spraying Systems Co.
Priority date: 2017-11-09
Filing date: 2018-11-09
Publication date: 2019-05-16

Abstract

A spray device (10) for discharging a liquid as a mist is provided. The spray device (10) includes a main body (12) including a reservoir (26) for storing the liquid to be discharged and an atomizing assembly (30) in fluid communication with the reservoir (26) and including an ultrasonic atomizing head (36) configured to shear the liquid into droplets using sound waves. A spray nozzle (14) includes a nozzle body (78) with an inlet (80) in communication with the atomizing assembly (30) and a discharge orifice (82). The nozzle body (78) defines a first passage (84) that communicates with the spray nozzle inlet (80) and the discharge orifice (82). The nozzle body (78) includes a charging electrode (90) arranged in a second passage (94) that connects to the first passage (84).

Description

ELECTROSTATICALLY CHARGED SPRAY

DEVICE WITH ULTRASONIC ATOMIZATION

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application claims the benefit of U.S. Provisional Patent Application No. 62/583,675, filed November 9, 2017, which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] Spray devices that produce a fine mist or fog have long been used in the agricultural industry for spraying liquids such as pesticides and fungicides. These devices have used hydraulics, heat or air to atomize the sprayed liquid. For example, with air atomized spray devices, a pressurized gas, such as air, is directed into the liquid being sprayed in order to mechanically break down the liquid into droplets. These types of sprayers are now starting to be used in the food, hospitality and medical industries for spraying cleaners, sanitizers and disinfectants on surfaces to be cleaned.

[0003] However, these fine mist or fog-type sprayers used in the agricultural industry have a number of drawbacks that make them unsuitable for use in an institutional setting such as a restaurant, hotel or hospital. For example, it can be difficult to control the size and/or consistency of the spray droplets. Additionally, it can be difficult to accurately control and direct the spray towards the surface being coated. As result, it can be difficult to achieve the desired uniformity and/or distribution of the spray on the surface being cleaned or sanitized. This can lead to inadequately cleaned surfaces. Moreover, the issues with inaccurately directed spray can make the cleaning process more time-consuming and inefficient as surfaces have to be sprayed repeatedly in order to achieve adequate coverage of cleaner, sanitizer or disinfectant.

OBJECTS OF THE INVENTION

[0004] In view of the foregoing, a general object of the present invention is to provide a spray device for producing a mist or fog that has improved control over the discharging spray. [0005] A related object of the present invention is to provide a spray device for producing a mist or fog with which it is easier to accurately control and direct the spray towards an area being coated.

[0006] A further object of the present invention is to provide a spray device for producing a mist or fog that can be used to spray surfaces in a more efficient and less time consuming manner than existing fog-type sprayers.

[0007] Another object of the present invention is to provide a spray device for producing a mist or fog that is suitable for use in the food, hospitality and medical industries for spraying cleaners, sanitizers and disinfectants on surfaces to be cleaned.

[0008] Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. The identified objects are not intended to limit the present invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0009] FIG. 1 is a perspective view of an exemplary mobile spray device according to the teachings of the present invention.

[0010] FIG. 2 is a perspective view of the fluid reservoir and atomizing assembly of the spray device of FIG. 1.

[0011] FIG. 3 is an exploded perspective view of the fluid reservoir and atomizing assembly of FIG. 2.

[0012] FIG. 4 is a partial vertical, cross-sectional perspective view of the fluid reservoir and atomizing assembly of FIG. 2.

[0013] FIG. 5 is a top view of the atomizing chamber of the atomizing assembly of FIG. 2.

[0014] FIG. 6 is a perspective view of the spray nozzle of the spray device of FIG. 1.

[0015] FIG. 7 is a partially cutaway perspective view of the spray nozzle of FIG. 6.

[0016] FIG. 8 is a partial cross-section view of the discharge end of the spray nozzle of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

[0017] Referring to FIG. 1 of the drawings, there is shown an exemplary embodiment of a spray device 10 in accordance with the present invention. The illustrated spray device 10 is configured to be capable of discharging a liquid as a fine mist or fog. The illustrated spray device 10 is particularly suited for discharging cleaners, sanitizers and/or disinfectants in institutional environments such as restaurant, hotel or medical facilities. However, the present invention is not limited to the spraying of such liquids or use in such environments. Rather, the spray device of the present invention is intended for spraying any suitable liquid that may be discharged as a fine mist or fog and in any suitable environment in which such a spray may be advantageous. The terms mist and fog are used interchangeably herein.

[0018] The spray device 10 generally includes a main body 12 and a spray nozzle 14 that is attached to the main body 12 via a flexible hose 16. To enhance mobility of the spray device, the illustrated main body 12 includes a set of wheels 20, 22 and a handle 18 that can be grasped by an operator of the spray device 10. More particularly, the main body 12 includes a pair of rear wheels 20 (one of which can be seen in FIG. 1) and a single pivotable front wheel 22. In the illustrated embodiment, the handle 18 extends upward from a column 23 at the rear of the main body 12. The handle 18 and wheel arrangement 20, 22 provides the spray device 10 with good maneuverability, which is advantageous when the spray device 10 is being used to spray cleaner, sanitizer and/or disinfectant in an institutional environment. In this instance, an operator interface 24 is provided on an upper surface of the rear column 23. The operator interface 24 may be configured to allow an operator to control and/or monitor various operations of the spray device as described in further detail below.

[0019] For storing the liquid that will be sprayed, the spray device 10 may include a reservoir 26. As shown in FIG. 2, the reservoir 26 may be removably received in a receptacle 28 formed in the center of an atomizing assembly 30. The illustrated reservoir 26 has a generally cylindrical configuration with a handle 32 at an upper end that facilitates removal of the reservoir 26 from the atomizing assembly receptacle 28 such as when the reservoir 26 is empty. The handle 32 also facilitates insertion of the reservoir 26 into the receptacle 28, such as after the reservoir is refilled with liquid. The atomizing assembly 30 and the reservoir 28 are, in turn, removably received in a central opening 34 in the main body 12 of the spray device 10 (the central opening 34 can be seen in FIG. 1). The central opening 34 in the main body 12 may be configured such that the atomizing assembly 30 and reservoir 28 may be inserted into and removed from the main body 12 as desired by an operator such as when switching between discharge liquids.

[0020] Being able to remove the atomizing assembly 30 from the main body 12 allows an operator to also empty the atomizing assembly 30 as desired when switching between discharge liquids. It also allows the atomizing assembly 30 to be flushed and cleaned as desired. Some discharge liquids may set-up or solidify if left sitting for an extended period. Additionally, the removability feature allows the atomizing assembly 30 to be replaced if it becomes damaged or worn out.

[0021] To provide atomization of the liquid being sprayed, the atomizing assembly 30 may be configured with one or more ultrasonic atomizing heads 36. In this case, the atomizing assembly 30 includes a main atomizing chamber 37 divided into multiple atomizing compartments 38 as best shown in FIG. 5. The multiple atomizing compartments 38 are arranged in an annular pattern surrounding the central reservoir receiving receptacle 28 of the atomizing assembly 30. In the illustrated embodiment, each compartment 38 has a generally cylindrical configuration with an open upper end and there are a total of twelve separate atomizing compartments 38. More particularly, each atomizing compartment 38 has a curved radially outer sidewall 40 that is relatively taller than a radially inner sidewall 42.

[0022] As shown in FIG. 5, each atomizing compartment 38 includes its own ultrasonic atomizing head 36 and is sized to contain a predetermined volume of fluid which is sufficient to ensure that the ultrasonic atomizing head 36 is submerged in the liquid. Each ultrasonic atomizing head 36 includes a body 43, a central vibrating element 44, a fluid level sensor 46 and a power connection 48 as best shown in FIG. 4. The ultrasonic atomizing head 36 may be configured such that when the power connection 48 is coupled to a power source (and the power source is activated) the vibrating element 44 vibrates at a high frequency producing ultrasonic sound waves. These ultrasonic sound waves causes liquid present at the ultrasonic vibrating element 44 to break down into a cloud of very fine droplets or particles. The fluid level sensor 46 on each ultrasonic atomizing head 36 ensures that sufficient liquid is present in the respective atomizing compartment 38 and can be configured such that the atomizing head 36 is shut down if the amount fluid in the corresponding compartment 38 is not sufficient to keep the vibrating element 44 submerged.

[0023] The use of multiple atomizing compartments 38 ensures that sufficient fluid remains in each compartment to submerge the vibrating element 44 even when the main body 23 is tipped off center. According to one embodiment, the multiple compartments 38 ensure that the vibrating elements remain submerged even if the main body 12 is tipped 15 degrees off center.

[0024] For controlling the flow of liquid out of the reservoir 26, the reservoir 26 may be provided with a liquid level control valve 50. In the illustrated embodiment, the liquid level control valve 50 is integrated into a cap 52 which threads onto an opening 54 on the reservoir 26 as shown in FIG. 4. When the reservoir 26 is inserted in the atomizing assembly receptacle 28 the reservoir opening 54, cap 52 and control valve 50 are at the lower end of the reservoir 26 such that fluid in the reservoir 26 feeds via gravity to the opening 54 and control valve 50. When refilling the reservoir 26 with spray liquid, an operator can remove the reservoir 26 from the atomizing assembly receptacle 28, remove the cap 52, fill the reservoir 26 with liquid through the opening 54, replace the cap 52 on the opening 54 when filled and reinsert the reservoir 26 in the receptacle 28.

[0025] To control the amount of fluid in the compartments 38 of the atomizing chamber 37, the liquid level control valve 50 may be configured to open when the reservoir 28 is arranged in the atomizing assembly receptacle 28 and the liquid level in the atomizing chamber 37 drops below a predefined level. As shown in FIG. 4, when in the atomizing assembly receptacle 28, the cap 52 on the reservoir 26 is received in a cylindrical socket 56 in the lower wall 57 of the receptacle 28. The cylindrical socket 56 surrounds a central opening 58 in the lower wall 57 of the receptacle 28 and is centered on a raised nub 60 on an upward facing center surface 62 of the atomizing assembly 30. When inserted in the socket 56, a valve stem 63 of the control valve 50 engages the nub 60 and is pushed upward allowing fluid to flow through the control valve 50 when the liquid level drops below the predefined level.

[0026] When the control valve 50 is open, fluid is able to flow out of the reservoir 26 through the central opening 58 in the lower wall 57 of the atomizing assembly receptacle 28 and into a fluid feed passage 64 as shown in FIG. 4. This fluid feed passage 64 communicates with each of the atomizing compartments 38 at the upper end of the inner sidewall 42 of the respective compartment 38. In this case, the fluid feed passage 64 is defined by the upward facing center surface 62 of the atomizing assembly 30 and the lower wall 57 of the receptacle 28 that receives the reservoir 26. Thus, the central opening 58 in the lower wall 57 of the receptacle 28 allows fluid exiting the reservoir 26 to flow into the fluid feed passage 64 which, in turn, allows the fluid to flow into the individual atomizing compartments 38.

[0027] For collecting and then carrying the mist produced by the ultrasonic atomizing heads 36 to the hose 16 and eventually to the spray nozzle 14, an annular air chamber 66 is defined in the space in the atomizing assembly 30 above the individual atomizing

compartments 38. The air chamber 66 is best shown in the cross-sectional view of FIG. 4. As shown in FIG. 2, the air chamber 66 includes an air inlet 68 to which a blower 70 may be connected for blowing external air tangentially into the air chamber 66 and an outlet 72 to which the hose 16 to the spray nozzle 14 may be connected. In the illustrated embodiment, the air chamber 66 is formed by an external ring 74 that when assembled on the atomizing assembly 30 is arranged in surrounding relation to an inner wall 76 of the atomizing assembly 30 that extends above the atomizing compartments 38 as shown in the exploded view of FIG. 3.

[0028] When in operation, the ultrasonic atomizing heads 36 send sound waves into the liquid in their respective atomizing compartment 38. These sound waves shear the liquid into different droplet sizes with the bigger droplets falling back into the liquid in the individual compartments 38. The smaller droplets produced by the ultrasonic action produced by the atomizing heads 36 rise and mix with, and are carried by, the air drawn into the air chamber 66 through the inlet 68 by the blower 70. The mist carried by the air in the air chamber 66 is directed towards, and then out, the outlet 72 from which it can be directed via the hose 16 to the spray nozzle 14 for discharge.

[0029] To provide more accurate control and direction of the discharging atomized mist, the spray nozzle 14 may be configured to electrostatically charge the liquid drops or particles making up the mist. As shown in FIGS. 6-8, the illustrated spray nozzle 14 generally includes a nozzle body 78 with an inlet opening 80 (shown in FIG. 7) to which the flexible hose 16 from the main body 12 of the spray device 10 is attached. In this case, a discharge orifice 82 is provided at the end of the nozzle body 78 opposing the inlet opening 80. The nozzle body 78 includes a first main internal passage 84 (see FIG. 7) that communicates with both the inlet opening 80 and the discharge orifice 82 such that the atomized mist stream entering the nozzle body 78 through the inlet opening 80 travels the length of the nozzle body 78 and is discharged from the discharge orifice 82. The nozzle body 78 may have an attached handle 86 that can be grasped by an operator of the spray device 10. The handle 86 may have an actuator switch 88 that can be used by the operator to, for example, turn off and on the spray nozzle 14 (i.e., start and stop the discharge of mist from the spray nozzle).

[0030] To provide the electrical charge for electrostatically charging the mist stream, the spray nozzle 14 may include a charging electrode 90. The charging electrode 90 is connected to a power supply 92, for example a high voltage power supply, which in this case is arranged in the nozzle body 78 generally below the handle 86. As shown in FIGS. 7 and 8, the charging electrode 90, which according to one embodiment may comprise a lOmohm resistor, is arranged in a second passage 94 of the nozzle body 78 which connects to the main mist passage 84 in a wye-type arrangement. As best shown in FIG. 8, the second electrode- containing passage 94 may connect to the first main mist passage 84 such that the second passage 94 forms an acute angle with the upstream portion of the main mist passage 84 (i.e., the portion of the main mist passage 84 upstream of the junction with the electrode containing second passage 94). As also shown in FIG. 8, the electrode 90 may be arranged such that an end portion of the electrode 90 extends a short distance into the main mist passage 84. The electrode 90 and power supply 92 may be configured to allow for varying of the produced voltage. For example, the electrode 90 and power supply 92 may be configured to produce a high voltage charge into the spray mist of 5Kv to 30Kv depending upon the spray liquid as different types of fluid could require different voltages to properly charge the fluid based on the fluid's conductivity. Additionally, the power supply 92 may be configured to provide either a positive or negative voltage to the charging electrode 90 depending on the fluid being discharged and/or the application in which the spray device 10 is being used.

[0031] To prevent the atomized mist from coming into contact with and condensing on the charging electrode 90, the spray nozzle 14 may be configured to produce a stream of dry shielding air in the second electrode-containing passage 94 in surrounding relating to the electrode 90. The stream of dry air may be produced by a fan 96 that is arranged to direct dry air down the second passage 94 toward the junction with the main mist passage 84. With this arrangement, the charging electrode 90 is kept dry (thereby avoiding a direct path to ground) while enabling the charging electrode 90 to be arranged close enough to the junction with the main mist passage 84 that the electrostatic fields produced by the charging electrode 90 can still project out into the mist stream.

[0032] To protect the operator and the main body 12 from electrical charge, a grounding element 98 may be provided that isolates the handle 86 of the spray nozzle 14 and the main body 12 from the high voltage of the charging electrode 90. In this case, the grounding element is configured as a ground ring 98 that extends around the inside surface of the main mist passage 84 just upstream of the junction with the electrode-containing second passage 94. This grounding ring 98 keeps everything upstream isolated from the high voltage.

Additionally, to keep the operator from being shocked, a grounding strip 100 may be provided on the handle 86 of the spray nozzle 14 that is arranged such that the grounding strip 100 comes into contact with the operator's hand when he/she holds the spray nozzle by the handle.

[0033] The disclosed spray device 10 may be configured to operate in two modes. More particularly, the spray device 10 may be operated in a handheld mode where the discharging mist may be directed by an operator holding the spray nozzle 14 by the handle 86 to achieve the desired coverage. In the handheld mode, when the operator actuates the actuator switch 88 on the handle 86 of the spray nozzle 14, the spray device controller will actuate the ultrasonic atomizing heads 36 and start the blower 70 on the atomizing assembly 30. Upon actuation of the actuator switch 88, the controller will also activate the high voltage power supply 92 of the spray nozzle 14 and the fan 96 that produces the shielding air in the electrode-containing second passage 94.

[0034] Alternatively, the spray nozzle 14 may be put into a parked positon to fog a room or area without the operator holding and directing the spray nozzle. For example, the handle 18 of the main body 12 may be configured to hold the spray nozzle 14 in such a parked position. In connection with the fogging mode, the control system of the spray device may be configured such as to allow entry by an operator of a set time for the duration of the discharge from the spray nozzle to produce the desired fogging. For example, the fogging duration may be entered by the operator through the operator interface 24 on the main body 12 of the spray device 10. After the time is entered and the operator starts the fogging sequence, a countdown timer corresponding to the desired fogging time would start and discharge of mist from the parked spray nozzle 14 would continue until the timer has expired. The control system may be further configured to allow a user to set a time for a signal that indicates that the fog produced by the spray device has sufficiently dissipated to allow the operator to reenter the area.

[0035] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0036] The use of the terms "a" and "an" and "the" and "at least one" and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term "at least one" followed by a list of one or more items (for example, "at least one of A and B") is to be construed to mean one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B), unless otherwise indicated herein or clearly

contradicted by context. The terms "comprising," "having," "including," and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0037] Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

Claims:

1. A spray device for discharging a liquid as a mist comprising:

a main body including a reservoir for storing the liquid to be discharged and an atomizing assembly, the atomizing assembly having an atomizing chamber including a plurality of atomizing compartments with each atomizing compartment being in fluid communication with the reservoir and containing an ultrasonic atomizing head configured to shear the liquid into droplets using sound waves, the main body including an air chamber configured to collect mist generated by the ultrasonic atomizing heads in the atomizing compartments; and

a spray nozzle including a nozzle body with an inlet in communication with the air chamber and a discharge orifice, the nozzle body defining a first passage that communicates with the spray nozzle inlet and the discharge orifice, the nozzle body including a charging electrode arranged in a second passage that connects to the first passage.

2. The spray device of claim 1 wherein the first passage and the second passage connect in a wye-type arrangement.

3. The spray device of claim 2 wherein the second passage forms an acute angle with an upstream portion of the first passage.

4. The spray device of claim 1 wherein an end portion of the charging electrode extends into the first passage.

5. The spray device of claim 1 wherein the spray nozzle includes a first blower in communication with the second passage and configured to produce a stream of dry shielding air in surrounding relation to the charging electrode.

6. The spray device of claim 1 wherein the spray nozzle includes a handle.

7. The spray device of claim 1 wherein the spray nozzle includes a grounding element that electrically isolates the handle from the charging electrode.

8. The spray device of claim 7 wherein the grounding element is a ground ring that extends around an inside surface of the first passage.

9. The spray device of claim 1 wherein the air chamber is arranged above the atomizing compartments and the main body includes a second blower for producing a flow of air in the air chamber that carries the mist collected in the air chamber to the spray nozzle.

10. The spray device of claim 1 wherein the spray nozzle is connected to the main body by a flexible hose.

11. The spray device of claim 1 wherein the reservoir is configured to be removable from the main body.

12. The spray device of claim 1 wherein the main body is wheeled.

13. A spray device for discharging a liquid as a mist comprising:

a main body including a reservoir for storing the liquid to be discharged and an atomizing assembly in fluid communication with the reservoir and including an ultrasonic atomizing head configured to shear the liquid into droplets using sound waves, the main body including an air chamber configured to collect mist generated by the ultrasonic atomizing heads; and

a spray nozzle including a nozzle body with an inlet in communication with the atomizing assembly and a discharge orifice, the nozzle body defining a first passage that communicates with the spray nozzle inlet and the discharge orifice, the nozzle body including a charging electrode arranged in a second passage that connects to the first passage in a wye- type arrangement with an end portion of the charging electrode extending into the first passage.

14. The spray device of claim 13 wherein the spray nozzle includes a first blower in communication with the second passage and configured to produce a stream of dry shielding air in surrounding relation to the charging electrode.

15. The spray device of claim 13 wherein the spray nozzle includes a handle.

16. The spray device of claim 13 wherein the spray nozzle includes a grounding element that electrically isolates the handle from the charging electrode.

17. The spray device of claim 13 wherein the grounding element is a ground ring that extends around an inside surface of the first passage.

18. The spray device of claim 13 wherein the spray nozzle is connected to the main body by a flexible hose.

19. The spray device of claim 13 wherein the reservoir is configured to be removable from the main body.

20. The spray device of claim 13 wherein the main body is wheeled.