EP4117824B1

EP4117824B1 - Spraying system for delivering cleaning foam

Info

Publication number: EP4117824B1
Application number: EP21713160.6A
Authority: EP
Inventors: Brian BAEKKE
Original assignee: Future Cleaning Technologies BV
Current assignee: Future Cleaning Technologies BV
Priority date: 2020-03-11
Filing date: 2021-03-10
Publication date: 2024-03-27
Anticipated expiration: 2041-03-10
Also published as: DE212021000331U1; EP4117824A1; NL2025098B1; EP4117824C0; WO2021182954A1

Description

TECHNICAL FIELD AND BACKGROUND

The present disclosure relates to a spraying system for delivering cleaning foam onto a target surface
As background, DE102005048489A1 describes a two-fluid nozzle with annular gap atomization; US 5,113,945 describes a foam/water/air injector mixer; and WO 03/068321 A1 describes a fire extinguishing arrangement. As further background US4330086A describes a nozzle and method for generating foam which includes a nozzle body, a nozzle inlet, an orifice, a gas inlet, an impingement pin and a nozzle outlet. The nozzle body has upstream and downstream ends and an inner wall defining a passage within the nozzle body. The nozzle inlet at the upstream end of the nozzle body permits introduction of a liquid foam producing agent into the passage. The foam producing agent then passes through the orifice, thereby forming a stream. This stream is directed past the gas inlets in the nozzle body to aspirate gas into the passage. The stream then impinges against the impingement pin which is disposed transversely across the passage. At least the upstream half of the cross-section of the impingement pin is annular so that the impingement pin disrupts the flow of the stream and splits it into secondary streams. These secondary streams pass outwardly on each side of the impingement pin and diverge with respect to each other prior to being deflected inwardly off the inner wall of the nozzle body. The nozzle outlet comprises a transverse slot disposed parallel to the impingement pin so that a thorough mixing between the gas and foam producing agent is effected prior to discharge through the nozzle outlet as foam.
There remains a need for improvements in the generation and control of foam patterns on target surfaces.

SUMMARY

Aspects of the present disclosure relate to a spraying system and method for delivering cleaning foam according to a predetermined spray pattern. A nozzle is configured to expel a cleaning liquid as a droplet spray from an exit aperture. The droplet spray propagates in diverging directions around a central axis. This can form the spray pattern on the target surface and according to a main spraying direction in front of the spraying system. A spray housing forms a diverging shell around the nozzle. The shell widens along the main spraying direction to accommodate the diverging directions of the droplet spray. The spray housing comprises an air intake configured to pass an air stream through the shell into the spray housing for interacting with the droplet spray to form the cleaning foam. By forming the spray housing as a shell around the nozzle this can act as a shield around the expelled spray. For example, the spray housing can shield a user from the spray and/or prevent inadvertent droplets going in undesired directions. Accordingly, the system can be more safe and accurate. By providing an air intake through the shell, more air can be sucked into the spray housing for interacting with the cleaning liquid. In combination, the shell of spray housing can act as a sort of chimney wherein the spray and air being expelled from the housing through the foam filter can cause an air stream to be sucked in through the air intake for efficient mixing.

BRIEF DESCRIPTION OF DRAWINGS

These and other features, aspects, and advantages of the apparatus, systems and methods of the present disclosure will become better understood from the following description, appended claims, and accompanying drawing wherein:

FIG 1A illustrates a spray section of a spraying system;
FIG 1B illustrates a liquid supply connected to the spray section with a mixing section there between;
FIG 2 illustrates various views of a preferred spray section;
FIG 3A illustrates a spray section generating an elongate spray pattern on a target surface;
FIG 3B illustrates preferred aspects of a nozzle to generate an elongate spray pattern;
FIGs 4A and 4B illustrate more preferred aspects of the nozzle;
FIGs 5A and 5B illustrate side and top translucent views of a mixing section to generate a cleaning liquid;
FIGs 6A and 6B illustrate a cross-section view of respective flows in a mixing section;
FIGs 7A and 7B illustrate respective side views of various modular parts.

DESCRIPTION OF EMBODIMENTS

Terminology used for describing particular embodiments is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term "and/or" includes any and all combinations of one or more of the associated listed items. It will be understood that the terms "comprises" and/or "comprising" specify the presence of stated features but do not preclude the presence or addition of one or more other features. It will be further understood that when a particular step of a method is referred to as subsequent to another step, it can directly follow said other step or one or more intermediate steps may be carried out before carrying out the particular step, unless specified otherwise. Likewise it will be understood that when a connection between structures or components is described, this connection may be established directly or through intermediate structures or components unless specified otherwise.
The invention is described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. In the drawings, the absolute and relative sizes of systems, components, layers, and regions may be exaggerated for clarity. Embodiments may be described with reference to schematic and/or cross-section illustrations of possibly idealized embodiments and intermediate structures of the invention. In the description and drawings, like numbers refer to like elements throughout. Relative terms as well as derivatives thereof should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description and do not require that the system be constructed or operated in a particular orientation unless stated otherwise.
FIG 1A illustrates a spray section 10 of a spraying system 100. In a preferred embodiment, the spray section 10 comprises a nozzle 11 configured to expel a cleaning liquid "M" as a droplet spray "S" from an exit aperture 11a of the nozzle 11. For example, the cleaning liquid "M" is received via a liquid intake 13 of the spray section 10. In some embodiments, e.g. as shown, the droplet spray "S" propagates in diverging directions around a central axis "Zc". This can determine a main spraying direction Z in front of the spraying system 100, e.g. where a spray pattern is formed on a target surface.
In another or further preferred embodiment, a spray housing 12 is provided, e.g. as part of the spray section 10, to form a diverging shell around the nozzle 11. Advantageously, the shell widens along the main spraying direction Z to accommodate the diverging directions of the droplet spray "S". Most preferably, the spray housing 12 comprises an air intake 12a configured to pass an air stream "L" through the shell into the spray housing 12. The air stream "L" can thus interact with the droplet spray "S" to form the cleaning foam "F".
As described herein, foam can be understood as an object formed by trapping pockets of gas in a liquid. Typically, the volume of gas is large, with thin films of (cleaning) liquid separating the regions of gas. Preferably, the foam is a cleaning foam, e.g. formed of a liquid comprising a cleaning chemical such as detergent or soap. Most preferably, the cleaning chemical is part of a tablet 40 which is mixed with the liquid stream, e.g. (clean) water, to form a cleaning liquid. For example, the cleaning liquid is configured to form a foam when droplet of the liquid are mixed with air. For example, the cleaning foam comprises bubbles formed of water with detergent. Preferably, the foam forms when leaving the spraying system 100. The foam can also form, or further develop, while in mid-air. The foam can also form or further develop when hitting the target surface "T", or thereafter.
Preferably, formation of the foam is promoted by a construction of the spraying system 100. Most preferably the spraying system is adapted, as described herein, to generate a foam with relatively small pockets or bubbles. Advantageously, the inventor finds that foam with relatively small bubbles can exhibit a relatively long dwell time. Without being bound by theory, foam with relatively small bubbles may have a greater tendency to stick to the target surface and/or experience less effect of gravity. As will be appreciated, the longer dwell time can be particularly advantageous for allowing the cleaning foam "F" to effect its cleaning action on the target surface "T".
In a preferred embodiment, the spray section 10 comprises a foam filter 14 connected to the spray housing 12 in front of the nozzle 11, wherein the foam filter 14 comprises a mesh 14m with openings for passing the droplet spray "S" expelled from the nozzle 11 interacting with the air stream "L" from the air intake 12a for generating the cleaning foam "F". Advantageously, the spray housing 12 can act as a structure for holding the foam filter 14 at a distance in front of the exit aperture 11a of the nozzle 11. In some embodiments, the foam filter 14 may determine a bubble size in the foam. For example, a size of openings through the mesh may correlate with the size of the foam bubbles. In some embodiments, the foam filter 14 may be used to finetune bubble creation. For example, a size of openings through the mesh 14m may correlate with a size of the bubbles. Preferably, the mesh 14m of the foam filter 14 forms openings therethrough, having a respective cross-section diameter of less than one millimeter, e.g. between a tenth of a millimeter and half a millimeter, or less. Within limits, smaller openings may promote smaller foam bubbles, which may have increased dwell time on the target surface "T".
In some embodiments, the spray housing 12 forms a widening shell with an elongate cross-section that increases towards a front of the spraying system 100 along the main spraying direction Z, wherein a first cross-section dimension Y of the widening shell increases more than a transverse, second cross-section dimension X of the elongate cross-section, e.g. by at least a factor two or three. By widening the spray housing 12 it can efficiently envelop the widening spray S of liquid droplets expelled from the spray section 10. Using an elongate widening shell, i.e. which is larger in one cross-section dimension than the other, the shell may better accommodate an elongate droplet spray "S" and/or spray pattern "P" as described herein. For example, the spray housing 12 has a(frustro)conical and/or (frustro)pyramidal shape wherein a base of the cone or pyramid (which is at the front) has a first cross-section dimension Y that is larger than a transverse, second cross-section dimension X, e.g. by at least a factor two
In other or further embodiments, the air intake 12a is disposed on a slope of the widening shell, which slope is at a divergence angle As with respect to the main spraying direction Z, wherein the divergence angle As is more than ten degrees (plane angle), e.g. between fifteen and sixty degrees, preferably between twenty and forty degrees. For example, the divergence angle As is half an opening angle of the diverging shell. By placing the air intake on substantial slope of the widening shell, air can be sucked into the spray housing at an angle, e.g. having some forward momentum. Without being bound by theory, air being sucked in a forward direction can more efficiently mix with liquid droplets which are expelled along a similar direction without substantially redirecting said droplet.
In one embodiment, (a center of) the air intake 12a is disposed at an axial offset ΔZ behind the exit aperture 11a of the nozzle 11 with respect to the main spraying direction Z, e.g. axially opposite with respect to an end of the nozzle from a front of the mixing section 20 where the foam filter 14 is placed. By placing the air intake at an axial offset behind the exit aperture of the nozzle, air can be sucked from behind at least partially in a direction where the spray is expelled from the nozzle. Advantageously, the air stream can be focused by the air intake primarily onto the exit aperture so it can most effectively mix with the expelled spray. For example, a (center line) of the air intake 12a may be generally directed towards an end of the nozzle 11. In another or further embodiment, (a center of) the air intake 12a is disposed at a vertical offset ΔY transverse to the central axis "Zc" above the exit aperture 11a of the nozzle 11. By placing the air intake 12a on a top side of the spray housing 12, it can be at least partially prevented that cleaning liquid drips from a bottom of the housing. Alternatively, or additionally, an air intake can be disposed on the bottom, e.g. below the central axis "Zc".
It will be understood that relative terms such as horizontal directions (X or Z), vertical direction (Y), horizontal plane (XZ), vertical plane (YZ), vertical offset (ΔY), axial offset (ΔZ), front, back, above, below, et cetera, are used for convenience to describe aspects shown in the figures or in orientations during use. The relative terms may also be defined e.g. with reference to a frame of the spraying system 100. For example, the axial offset ΔZ can be determined along the main spraying direction Z, e.g. a direction faced by the exit aperture 11a of the nozzle 11 and/or a direction faced by a front of the spraying system 100 formed by the foam filter 14. For example, the vertical offset ΔY can be determined along a vertical axis Y, transverse to the axial offset ΔZ. For example, in normal use, the vertical axis Y can point upwards (against a gravitational vector) when viewing the spraying system 100 as shown in the figures. Of course, it will be understood that the system can be rotated. Accordingly, terms such as above, below, or behind can be understood in a frame of the spraying system 100 as shown in normal used. In some embodiments, an orientation of the system is determined by its various sections. For example, the mixing chamber 21 is preferably on an underside of the mixing section 20. An orientation can also be derived from the way it is intended to be held. For example, the spraying system 100 comprises a handle which may determine its default orientation. In some embodiments, e.g. as shown, the handle or pistol grip faces in a general downward directions.
FIG 1B illustrates an embodiment wherein a liquid supply 30 is connected to the spray section 10 with a mixing section 20 there between. In a preferred embodiment, the spraying system 100 comprises a mixing section 20 with a mixing chamber 21 configured to hold a tablet 40 comprising a cleaning chemical. For example, the mixing section 20 can receive a base liquid "W" from a liquid supply 30 and pass a stream of the base liquid "W" along the tablet 40. Accordingly the cleaning chemical of the tablet 40 can be mixed in the base liquid "W" to form the cleaning liquid "M". The cleaning liquid "M" can e.g. be directed towards the spray section 10;
By mixing a base liquid "W" such as (clean water) with a cleaning chemical from a tablet, a large tank of cleaning liquid "M" can be avoided. For example, the base liquid "W" can be supplied directly from a tap or other source. Alternatively, or additionally, the spray section 10 can be directly connected to a liquid supply 30, e.g. a reservoir with cleaning liquid "M". Preferred features of the mixing section 20 will be further elucidated later with reference to FIGs 5 and 6.
In some embodiments, a liquid supply 30 is configured to at least partially control a liquid stream passing the spraying system 100. For example, the liquid supply 30 is configured to control a flow rate (amount of liquid per unit time) entering the mixing section 20 and/or spray section 10. For example, the liquid supply 30 is configured to control a pressure of liquid at an entrance of the mixing section 20 and/or spray section 10. In some embodiments, the base liquid "W" and/or cleaning liquid "M" can be provided via a pump e.g. to increase pressure if necessary. Alternatively, the base liquid "W" is provided at a nominal pressure, e.g. of a water tap.
In other or further embodiments, the liquid supply 30 comprise one or more controllable valves (not shown). In one embodiment, a first valve is configured to allow or block the liquid stream. For example, the first valve can be controlled manually by a push button. Optionally, the push button comprises a locking mechanism, e.g. to lock the first valve in the open position. In another or further embodiment, a second valve is configured to set a pressure and/or amount of liquid, e.g. when the first valve is open. Also other or further control mechanisms and/or valves can be envisaged. For example, a controllable valve can be configured to vary the amount of flow from a blocked flow to a full flow. The liquid stream or flow can also be controlled at least partially by other or further sections of the spraying system 100, e.g. the mixing section 20 and/or liquid supply 30.
In a preferred embodiment, e.g. as shown, the spraying system 100 comprises(or can be coupled to) a handle 35 for holding the system 100. For example, the handle 35 is formed as a pistol grip, or otherwise. Typically the handle 35 is coupled to an entrance 23 of the mixing section 20. In one embodiment, the liquid supply 30, e.g. handle, comprises a first control mechanism 31 configured to control a first valve for variably setting a flow rate of the liquid stream. In another or further embodiment, the liquid supply 30, e.g. handle, comprises a second control mechanism 32 configured to control a second valve for allowing or blocking the liquid stream. In another or further embodiment, the liquid supply 30, e.g. handle, comprises a third control mechanism 33 configured to lock or unlock the second control mechanism 32. Preferably, the liquid supply 30, e.g. handle 35, is reversibly connectable to the mixing section 20, e.g. wherein the handle can be replaced. Typically, an entrance to the handle 35 is connected to (flexible) hose. For example, another end of the hose is connected to a liquid reservoir or tap. Also other embodiments can be envisaged, e.g. without a handle. For example, the mixing section 20 can be directly connected to a hose.
Aspects of the present disclosure can also be embodied as a corresponding method for delivering cleaning foam "F" onto a target surface "T" according to a predetermined spray pattern "P". In one embodiment, a cleaning liquid "M" is expelled as a droplet spray "S" from an exit aperture 11a of a nozzle 11. In another or further embodiment, the droplet spray "S" propagates in diverging directions (Ax,Ay) around a central axis "Zc" to form the spray pattern "P" on the target surface "T" determining a main spraying direction Z in front of the spraying system 100. In another or further embodiment, a spray housing 12 forms a diverging shell around the nozzle 11. For example, the shell widens along the main spraying direction Z to accommodate the diverging directions Ax,Ay of the droplet spray "S". Most preferably, the spray housing 12 comprises an air intake 12a passing an air stream "L" through the shell into the spray housing 12 interacting with the droplet spray "S" to form the cleaning foam "F".
In some embodiments, the cleaning foam "F" can be rinsed after some dwell time. For example, the cleaning foam "F" can be rinsed by spraying clean water using another spraying system, or the same spraying system (e.g. without mixing section 20 and/or without the tablet 40). As will be appreciated, the spraying system 100 can be used for cleaning various target surfaces by delivering foam and optionally removing the foam after a dwell time. In one embodiment, the spraying system 100 comprises or couples to a special rinsing tool or lance comprising a rinsing nozzle. For example, the liquid supply 30 comprises or (directly) couples to the lance for spraying a rinsing fluid, e.g. water, to remove the cleaning foam F. Alternatively, it can be envisaged that the foam is of a consistency which does not need rinsing.
FIG 2 illustrates various views of a preferred spray section 10. The cross-sections views X-X, Y-Y, and Z-Z corresponds to the various cuts as indicated. For example, the top-right figure labeled X-X illustrates a cross-section in a vertical plane through the nozzle 11 as indicated in the bottom-left figure. For example, the middle-right figure labeled Y-Y illustrates a cross-section in a horizontal plane through the nozzle 11 as indicated in the bottom left figure and the top-right figure. For example, the bottom-right figure labeled Z-Z illustrates a cross-section in another vertical plane through the nozzle 11, and air intakes, as indicated in the top-right figure.
In some embodiments, the spray section 10 has one or more additional side intakes 12b for air on one or both side through the shell. For example, a side intake 12b can be disposed adjacent the nozzle 11 and allow further air inflow. Preferably, each side intake 12b is formed as a funnel, e.g. being wider outside than inside the shell of the housing. In this way air can more easily enter the shell and/or be focused as well on the exit aperture 11a of the nozzle for efficient foam formation.
In a preferred embodiment, the nozzle has an ending which forms a sort of nozzle mouth 11m, e.g. with protrusions pointing apart with an opening angle "Am" as shown in the middle-right figure. Advantageously, the nozzle mouth 11m may help to promote generation of an elongate spray pattern "P" as will be described in the following.
FIG 3A illustrates a spray section 10 generating an elongate spray pattern "P" on a target surface "T". In a preferred embodiment, the spray section 10 is configured to generate an elongate spray pattern "P" on the target surface "T", wherein a height Py of the spray pattern "P" is more than a width Px of the spray pattern "P", e.g. by at least ten percent, at least twenty percent, at least fifty percent (factor one-and-half), at least a factor two, or more.
In other or further embodiments, the spray section 10, in particular the nozzle is configured to expel the spray of droplets with a horizontal opening angle "Ax" smaller than vertical opening angle "Ay". For example, the spraying system 100 is configured to project the cleaning foam "F" onto the target surface "T" along a diverging elliptical cone according to the vertical opening angle "Ay" and horizontal opening angle "Ax" in which the droplets are expelled from the nozzle 11. By spraying the cleaning foam "F" onto the target surface "T" in an elongate pattern, a user can have more control over a position where the foam lands (e.g. depending on an angle of the pattern with respect to the surface) while still being able to quickly cover a large areas (e.g. by moving the device in a direction transverse to the elongate axis of the pattern).
In some embodiments, the horizontal opening angle "Ax" is less than ninety degrees (plane angle), preferably less than eighty degrees, less than seventy degrees, less than sixty degrees, e.g. between ten and fifty degrees. In other or further embodiments, the vertical opening angle "Ay" is more than ninety degrees, more than hundred degrees, more than hundred-and-ten degrees, e.g. between hundred-and-twenty and hundred-and-fifty degrees. As will be appreciated the opening angles may determine how much of the target surface is instantly covered (without moving the device) and/or how quickly the target surface can be completely covered (by moving the device) and/or an ideal distance between the spraying system and the target surface.
FIG 3B illustrates preferred aspects of a nozzle 11 to generate an elongate spray pattern "P". Typically, the nozzle 11 is configured to expel the droplet spray "S" in a divergent pattern, e.g. along a cone with its apex at the exit aperture 11a. For example, the spraying system 100 is configured to project the cleaning foam "F" in a cone around the main spraying direction Z. For example, the cone has one or more opening angles Ax,Ay which can be the same or different. Most preferably one or the opening angles is significantly larger than the other.
In a preferred embodiment, the nozzle 11 comprises a V-shaped nozzle mouth 11m concavely extending into and cutting along a vertical direction Y transverse to the main spraying direction Z across an end of the nozzle 11, wherein the V-shape of the nozzle mouth 11m is formed by respective jaws 11j extending outward according to an opening angle Am of the nozzle mouth 11m between the jaws 11j, wherein the exit aperture 11a is disposed centrally between the respective jaws 11j, e.g. forming as it were a 'throat' of the nozzle mouth 11m. Most preferably, the nozzle 11 comprises or is formed by a protruding shape, e.g. ending in the nozzle mouth 11m. By using a protruding nozzle shape, substantial air can be disposed around, e.g. also behind, the exit aperture 11a.
In one embodiment, the nozzle 11 is configured to generate the spray pattern diverging with a vertical opening angle "Ay" in a vertical plane "YZ", along the vertical direction Y of the cut of the V-shaped mouth transverse to the spraying direction Z. In another or further embodiment, the nozzle 11 is configured to generate the spray pattern diverging with a horizontal opening angle "Ax" in a horizontal plane "XZ", transverse to the vertical plane XZ, determined by the opening angle Am of the nozzle mouth 11m. For example, the horizontal plane "XZ" is transverse the vertical plane "YZ". Preferably, the vertical opening angle "Ay" is larger than the horizontal opening angle "Ax", e.g. by at least ten percent, at least twenty percent, at least fifty percent (factor one-and-half), at least a factor two, or more.
FIG 4A illustrates a translucent perspective view of a preferred nozzle 11. FIG 4B illustrates a corresponding cutaway view to show aspects inside the nozzle. In some embodiments, the cleaning liquid "M" is guided through the nozzle 11 via a liquid duct 11d, e.g. inner tube. Preferably, the liquid duct 11d starts with an initial diameter 11i which decreases towards the exit aperture 11a. For example, the exit aperture has an ending diameter 11e smaller than the initial diameter 11i, e.g. by at least ten percent, at least twenty percent, or even at least fifty percent (factor one-and-half smaller). Most preferably, a cross-section of the liquid duct 11d is substantially round (or elliptical) ending in a smooth rounded contour 11c which (gradually) converges towards the exit aperture 11a. For example, the rounded converging contour 11c of the liquid duct 11d may promote desired liquid flow ending in spray pattern diverging, as described herein, when exiting the exit aperture 11a. In another or further embodiment, an outside contour of the nozzle 11 can be substantially rectangular (or rounded rectangular) in cross-section. For example, sides of the rectangular shape can be oriented parallel to the nozzle mouth 11m and/or jaws 11j.
FIGs 5A and 5B illustrate side and top translucent views of a mixing section 20 to generate a cleaning liquid "M". In some embodiments, the mixing section 20 comprises a mixing control 22 configured to control the stream of the base liquid "W" along the tablet 40 for determining an amount of the cleaning chemical being mixed in the base liquid "W". For example, the mixing control 22 comprises an externally accessible interface such as a rotatably dial, button, and/or lever, which is coupled to one or more valves inside the mixing section 20 to control respective one or more streams of the base liquid "W" and/or cleaning liquid "M".
FIGs 6A and 6B illustrate a cross-section view of respective flows in a mixing section 20. In some embodiments, the mixing control 22 is configured to determine a relative volumetric flow rate of the base liquid "W" being directed towards the mixing chamber 21 where the tablet 40 is held. Preferably, a first part "W1" of a flow of base liquid "W" received via an entrance 23 of the mixing section 20 (e.g. from the liquid supply 30), is directed towards the mixing chamber 21 whereas another, second part "W2" is directed to a second chamber 24 of the mixing section 20 (without tablet). In one embodiment, the second part "W2" bypasses the mixing chamber 21 and/or is mixed only with a part "M2" of mixed liquid received indirectly via the mixing chamber 21.
In some embodiments, at least a first part "M1" of mixed liquid generated in the mixing chamber 21 is directed to an exit 13 of the mixing section 20, e.g. connected to the spray section 10. In other or further embodiments, at least a second part "M2" of mixed liquid generated in the mixing chamber 21 is directed to the second chamber 24 of the mixing section 20. In other or further embodiments, a third part "M3" mixed liquid is directed from the second chamber 24 to the exit 13. For example, the third part "M3" comprises a mix of the second part "M2" of the mixed liquid from the mixing chamber 21 with the second part "W2" of the base liquid "W" from the entrance 23. In one embodiment, the mixing control 22 is configured to determine relative volumetric flow rates of the respective parts "W1" and"W2" of the base liquid "W" by opening or closing respective passages to the mixing section 20 and/or second chamber 24. For example, the mixing control 22 comprises an externally accessible control interface 22i connected to a valve 22v which opens or closes the respective passages, e.g. via a screw connection or otherwise.
FIG 7A illustrate respective parts of a spraying system 100. Preferably the system is modular, e.g. having different parts that can be reversibly and easily attached and detached from each other. For example, the various parts can be connected via respective click, snap, and/or screw mechanisms. Also other types of connections can be envisaged. In one embodiment, e.g. as shown, an intermediate connection piece 36 is provided. For example, the intermediate connection piece 36 has a specific connection on one side to connect to an entrance of the mixing section 20; and a universal connection on another side to connect to various existing types of liquid supply, e.g. a snap connection such as used for connecting a garden hose. FIG 7B illustrates how parts of the spraying system 100 as described herein can be replaced by a rinsing tool 37, e.g. comprising a nozzle connecting to the liquid supply 30 as described. For example, the rinsing nozzle 37 is used for spraying water to rinse the cleaning foam sometime after application.
For the purpose of clarity and a concise description, features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described. For example, while embodiments were shown for a spraying system which includes a spray section, mixing section, and liquid supply, also alternative ways may be envisaged by those skilled in the art having the benefit of the present disclosure for achieving a similar function and result. E.g. the sections may be combined to provide synergetic advantages, or split up to provide separate advantages. The various elements of the embodiments as discussed and shown offer certain advantages, such as delivery of specific foam patterns on a target surface. Of course, it is to be appreciated that any one of the above embodiments or processes may be combined with one or more other embodiments or processes to provide even further improvements in finding and matching designs and advantages. It is appreciated that this disclosure offers particular advantages to the cleaning industry, and in general can be applied for any application wherein foam is generated efficiently and with high control over the deposition.
In interpreting the appended claims, it should be understood that the word "comprising" does not exclude the presence of other elements or acts than those listed in a given claim; the word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements; any reference signs in the claims do not limit their scope; several "means" may be represented by the same or different item(s) or implemented structure or function; any of the disclosed devices or portions thereof may be combined together or separated into further portions unless specifically stated otherwise. Where one claim refers to another claim, this may indicate synergetic advantage achieved by the combination of their respective features.

Claims

A spraying system (100) for delivering cleaning foam (F) onto a target surface (T) according to a predetermined spray pattern (P), the system comprising a spray section (10) including
- a nozzle (11) configured to expel a cleaning liquid (M) as a droplet spray (S) from an exit aperture (11a) of the nozzle (11), wherein the droplet spray (S) propagates in diverging directions (Ax,Ay) around a central axis (Zc) to form the spray pattern (P) on the target surface (T) determining a main spraying direction (Z) in front of the spraying system (100); and

- a spray housing (12) forming a diverging shell around the nozzle (11), wherein the shell widens along the main spraying direction (Z) to accommodate the diverging directions (Ax,Ay) of the droplet spray (S), characterized in that the diverging shell formed by the spray housing (12) around the nozzle (11) comprises an air intake (12a) configured to pass an air stream (L) through the shell into the spray housing (12) for interacting with the droplet spray (S) that has been expelled from the exit aperture (11a) to form the cleaning foam (F).
The system according to the preceding claim, wherein the nozzle (11) ends in a protruding shape with a V-shaped nozzle mouth (11m) concavely extending into and cutting along a vertical direction (Y) transverse to the main spraying direction (Z) across an end of the nozzle (11), wherein the V-shape of the nozzle mouth (11m) is formed by respective jaws (11j) extending outward according to an opening angle (Am) of the nozzle mouth (11m) between the jaws (11j), wherein the exit aperture (11a) is disposed centrally between the respective jaws (11j), wherein the nozzle (11) is configured to generate the spray (S) diverging with a horizontal opening angle (Ax) in a horizontal plane (XZ), transverse to the vertical plane (XZ), determined by the opening angle (Am) of the nozzle mouth (11m).
The system according to the preceding claim, wherein the nozzle (11) is configured to generate the spray pattern diverging with a vertical opening angle (Ay) in a vertical plane (YZ), along the vertical direction (Y) of the cut of the V-shaped mouth transverse to the spraying direction (Z), and diverging with a horizontal opening angle (Ax) in a horizontal plane (XZ), transverse the vertical plane (YZ), wherein the vertical opening angle (Ay) is larger than the horizontal opening angle (Ax).
The system according to any of the two preceding claims, wherein the cleaning liquid (M) is guided through the nozzle (11) via a liquid duct (11d) starting with an initial diameter (11i) which decreases towards the exit aperture (11a), which exit aperture has an ending diameter (11e) smaller than the initial diameter (11i), wherein a cross-section of the liquid duct (lId) is round ending in a smooth rounded contour (11c) which gradually converges towards the exit aperture (11a), wherein an outside contour of the nozzle (11) is rectangular with respective sides of the rectangular shape be oriented parallel to the jaws (11j) of the nozzle mouth (11m).
The system according to any of the preceding claims, wherein the spray housing (12) forms a widening shell with an elongate cross-section that increases towards a front of the spraying system (100) along the main spraying direction (Z), wherein a first cross-section dimension (Y) of the widening shell increases more than a transverse, second cross-section dimension (X) of the elongate cross-section.
The system according to any of the preceding claims, wherein the air intake (12a) is disposed on a slope of the widening shell, which slope is at a divergence angle (As) with respect to the main spraying direction (Z), wherein the divergence angle (As) is more than twenty degrees.
The system according to any of the preceding claims, wherein the air intake (12a) is disposed at an axial offset (ΔZ) behind the exit aperture (11a) of the nozzle (11) with respect to the main spraying direction (Z), and at a vertical offset (ΔY) transverse to the central axis (Zc) above the exit aperture (11a) of the nozzle (11).
The system according to any of the preceding claims, wherein the spraying system (100) comprises a mixing section (20) with a mixing chamber (21) configured to hold a tablet (40) comprising a cleaning chemical, receive a base liquid (W) from a liquid supply (30), pass a stream of the base liquid (W) along the tablet (40) for mixing the cleaning chemical of the tablet (40) in the base liquid (W) to form the cleaning liquid (M), and direct the cleaning liquid (M) towards the spray section (10).
The system according to the preceding claim, wherein the mixing section (20) comprises a mixing control (22) configured to control the stream of the base liquid (W) along the tablet (40) for determining an amount of the cleaning chemical being mixed in the base liquid (W).
The system according to the preceding claim, wherein the mixing control (22) is configured to determine a relative volumetric flow rate of the base liquid (W) being directed towards the mixing chamber (21) where the tablet (40) is held, wherein a first part (W1) of a flow of base liquid (W) received via an entrance (23) of the mixing section (20), is directed towards the mixing chamber (21), whereas another, second part (W2) of the flow of base liquid is directed to a second chamber (24) of the mixing section (20), wherein the second part (W2) bypasses the mixing chamber (21) and/or is mixed only with a part (M2) of mixed liquid received indirectly via the mixing chamber (21).
The system according to any of the three preceding claims, wherein a first part (M1) of mixed liquid generated in the mixing chamber (21) is directed to an exit (13) of the mixing section (20) and a second part (M2) of mixed liquid generated in the mixing chamber (21) is directed to the second chamber of the mixing section (20), wherein a third part (M3) of mixed liquid is directed from the second chamber (24) to the exit (13).
The system according to any of the preceding claims, wherein the spraying system (100) comprises a handle (35) for holding the system (100), wherein the handle (35) is coupled to an entrance (23) of the mixing section (20) and comprises
- a first control mechanism (31) configured to control a first valve for variably setting a flow rate of the liquid stream;

- a second control mechanism (32) configured to control a second valve for allowing or blocking the liquid stream; and

- a third control mechanism (33) configured to lock or unlock the second control mechanism (32).
The system according to any of the preceding claims, the spray section (10) comprises a foam filter (14) connected to the spray housing (12) in front of the nozzle (11), wherein the foam filter (14) comprises a mesh (14m) with openings for passing the droplet spray (S) expelled from the nozzle (11) interacting with the air stream (L) from the air intake (12a) for generating the cleaning foam (F), wherein the mesh has openings with a respective cross-section diameter of less than one millimeter.
A method for delivering cleaning foam (F) onto a target surface (T) according to a predetermined spray pattern (P), the method comprising expelling a cleaning liquid (M) as a droplet spray (S) from an exit aperture (11a) of a nozzle (11), wherein the droplet spray (S) propagates in diverging directions (Ax,Ay) around a central axis (Zc) to form the spray pattern (P) on the target surface (T) determining a main spraying direction (Z) in front of the spraying system (100), wherein a spray housing (12) forms a diverging shell around the nozzle (11), wherein the shell widens along the main spraying direction (Z) to accommodate the diverging directions (Ax,Ay) of the droplet spray (S), characterized in that the diverging shell formed by the spray housing (12) around the nozzle (11) comprises an air intake (12a) passing an air stream (L) through the shell into the spray housing (12) interacting with the droplet spray (S) that has been expelled from the exit aperture (11a) to form the cleaning foam (F).
The method according to the preceding claim, wherein the nozzle (11) generates the spray pattern diverging with a vertical opening angle (Ay) in a vertical plane (YZ), along a vertical direction (Y) of a cut formed in an protruding ending of the nozzle (11) by a V-shaped mouth transverse and the spraying direction (Z), and diverging with a horizontal opening angle (Ax) in a horizontal plane (XZ), transverse the vertical plane (YZ), wherein the vertical opening angle (Ay) is larger than the horizontal opening angle (Ax), wherein the spray housing (12) forms a widening shell to accommodate the diverging spray pattern with an elongate cross-section that increases towards a front of the spraying system (100) along the main spraying direction (Z), wherein a first cross-section dimension (Y) of the widening shell increases more than a transverse, second cross-section dimension (X) of the elongate cross-section.