Patent Description:
Diffusion devices in the past have had the ability to dispense scent or other liquids throughout the atmosphere of desired spaces but have suffered from several drawbacks. Changing the scent or product that is being diffused has typically required that a reservoir of the diffusing device be emptied and then filled with the new liquid or scent. Conventional reservoirs may be configured to be refilled directly with the liquid to be diffused, which can be messy or have a highly concentrated odor. This refilling may not be desirably carried out in a public setting, such as a store, restaurant, casino or other commercial setting where the scent or other product may be diffused. Additionally, having to deal with bulk refills that must be poured or otherwise placed into the reservoir of the diffusion device may not be a desirable arrangement for home or non-commercial diffusion devices. An improved ability to refill or recharge a diffusion device with scent or other product is desirable.

Some diffusion devices have been developed to address the aforementioned issues by enabling a cartridge containing the liquid to be diffused to be removed from a host device upon depletion of the liquid and replaced with another like cartridge. Such diffusion devices and removable cartridges thereof, however, may be overly complex, costly and/or suffer from other deficiencies or drawbacks, such as, for example, discharging diffused liquid with less than ideal characteristics, or the cartridges being susceptible to leakage, tampering, fouling and/or contamination. Accordingly, Applicant believes that improved cartridges and cartridge components for liquid diffusion devices are desirable. Further relevant prior art are described in <CIT>, <CIT> and <CIT>.

The removable cartridges for use with liquid diffusion devices and components thereof shown and described herein provide removable cartridges and cartridge components (e.g., multi-functional inserts) with efficient form factors that are particularly effective at treating spaces with diffused liquid having extremely small liquid particles. In particular it is provided a cartridge having the features defined in claim <NUM>.

At least one embodiment of an insert of a cartridge for use with a liquid diffusion device may be summarized as including a body, an inlet provided in the body to receive diffused liquid generated within the cartridge during operation of the liquid diffusing device, an outlet zone defined at least in part by the body through which to discharge the diffused liquid toward an external environment, and a tortuous passage extending between the inlet and the outlet zone to aid in further reducing an average particle size of the diffused liquid as the diffused liquid moves through the tortuous passage.

The inlet may be located at a periphery of the body, the outlet zone may be located at a central region of the body, and the tortuous passage may spiral between the inlet and the outlet zone. The tortuous passage may be open in an upward direction. The body may be formed as a single, unitary piece that includes the tortuous passage. A lower portion of the body may include an indentation having an impact surface to be impinged upon by diffused liquid during operation of the liquid diffusing device. The impact surface may diverge in a downward direction to direct liquid condensed thereon radially outward and downward. The tortuous passage may be at least partially defined by a vertical sidewall of the body. The tortuous passage may follow a non-linear path that assists in preventing liquid from leaking from the cartridge when the cartridge is upended. A cross-sectional profile of at least a portion of the tortuous passage may narrow in a downstream direction.

At least one embodiment a cartridge for use with a liquid diffusing device may be summarized as including a cartridge housing defining an internal housing cavity partially filled with a liquid to be diffused, a diffusion head positioned within the internal housing cavity, which includes a venturi device for generating a diffused liquid from the liquid contained in the internal housing cavity, and an insert positioned downstream of the diffusion head. The insert may include an inlet to receive the diffused liquid generated by the venturi device, an outlet zone through which to discharge the diffused liquid toward an external environment, and a tortuous passage extending between the inlet and the outlet zone.

The insert may be sandwiched between the cartridge housing and the diffusion head. An upper portion of the diffusion head and a lower portion of the insert may define a primary expansion chamber immediately above the venturi device, a secondary chamber may be provided external of the diffusion head and the insert, and a tertiary chamber may be provided by the tortuous passage of the insert. The primary expansion chamber may be in fluid communication with the internal housing cavity external of the diffusion head via a plurality of apertures provided in the upper portion of the diffusion head. The upper portion of the diffusion head may define a bulkhead that impedes the diffused liquid generated by the venturi device from exiting the primary expansion chamber other than through the plurality of apertures.

The tortuous passage of the insert may provide the sole passage for the diffused liquid generated by the venturi device to exit the cartridge. The tortuous passage of the insert may be configured to provide a convoluted flow path that retards a flow of the liquid to be diffused through the insert when the cartridge is temporarily held upside-down. An initial fill level of the liquid to be diffused may be below the venturi device when the removable cartridge is upright and below a central axis of the cartridge housing when the removable cartridge is upended and rests sideways, and the tortuous passage may be configured to provide a convoluted flow path that includes a portion above the central axis when the cartridge is upended and rests sideways to prevent the liquid to be diffused from traversing the entirety of the tortuous passage.

In the following description, certain specific details are set forth in order to provide a thorough understanding of various disclosed embodiments. However, one skilled in the relevant art will recognize that embodiments may be practiced without one or more of these specific details. In other instances, well-known devices, structures and techniques associated with liquid diffusion devices, components thereof and related methods of diffusing liquid may not be shown or described in detail to avoid unnecessarily obscuring descriptions of the embodiments. For example, embodiments of the removable cartridges and cartridge components (e.g., cartridge inserts) disclosed herein may be used in a wide variety of host diffusion devices, including those with an onboard pressurized gas source (e.g., an air compressor or pump) and a control system for discharging diffused liquid in regular or irregular duty cycles or as otherwise desired. Such diffusion devices, which may be adapted to receive embodiments of the cartridges and cartridge components described herein are not shown or described in further detail to avoid unnecessarily obscuring descriptions of such embodiments. Examples of diffusion devices and aspects and related methods thereof which may be used in combination with the cartridge and cartridge components described herein are shown in <CIT><CIT> and<CIT>.

Unless the context requires otherwise, throughout the specification and claims which follow, the word "comprise" and variations thereof, such as, "comprises" and "comprising" are to be construed in an open, inclusive sense, that is as "including, but not limited to.

As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. It should also be noted that the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise.

The present disclosure relates generally to liquid diffusion devices and more specifically to a removable cartridge <NUM>, <NUM> for use with a diffusion device where the liquid to be diffused is contained within the cartridge <NUM>, <NUM>, and to components thereof and related methods of discharging diffused liquid into a space. The cartridges <NUM>, <NUM> described herein may be used with a diffusion device or system having a unit or housing adapted to removably receive the cartridges <NUM>, <NUM> such that the diffusion device or system can be recharged with liquid to be diffused. In some instances, a diffusion device may be provided which includes such a unit or housing, a removable liquid cartridge <NUM>, <NUM> and a cover enclosing both the unit or housing and the cartridge <NUM>, <NUM>, similar to the example diffusion devices shown and described in <CIT>One or more operational controls or status indicators may be provided for operating the device and an outlet or opening may be provided in the device to permit a diffused liquid generated from the liquid within the cartridge <NUM>, <NUM> to be discharged into the environment about the device. When received in a host diffusion device, the removable cartridge <NUM>, <NUM> engages or is otherwise coupled to an outlet of a source of pressurized gas to enable the pressurized gas to be selectively passed through the cartridge <NUM>, <NUM> as described herein to diffuse the liquid contained therein. The gas used to drive the diffusion of the liquid may be any of a variety of inert gases. In some instances, the diffusion device may include an air compressor utilizing normal room air to drive the diffusion. However, other gases such as but not limited to nitrogen, carbon dioxide, or other similar atmospheric gases might be used. It may also be desirable to use a gas that reacts with the liquid to be diffused, such as but not limited to oxygen and other non-inert gases. Also, the diffusion device might utilize, for example, but be not limited to, an onboard compressor, an onboard source of compressed gas such as a pressurized reservoir, or connection to an external source of compressed gas.

Within the present disclosure, the terms atomize and diffuse are used in their various forms interchangeably. They are intended to refer to generally the same action, that being the dispersion of liquid into very small particle sizes (preferably but not limited to one micron or less in size) and releasing the particles into the atmosphere of a generally enclosed space. Discharging diffused liquid with particularly small particles helps ensure that the liquid to be dispersed remains airborne long enough to effectively treat the space.

One approach to providing small particle sizes is to incorporate a dispersion or gas-liquid mixing location adjacent an expansion chamber. The mixed gas and liquid combination may contain particles of greater than desirable size. Allowing this mix to remain resident within the expansion chamber prior to release into the treated space will allow larger particles to precipitate out of the mix. Structures that a flow of the gas and liquid mix impinge upon may also assist in the collection of these larger particles and leave only the desired predominantly smaller sized particle to be released. The expansion chamber may be maintained at a positive pressure with respect to the atmospheric pressure within the space to be treated, so that the gas and liquid mix will be injected from the device into the space. Alternatively, the expansion chamber may generally be maintained at the atmospheric pressure of the space to be treated with the flow of gas through the chamber providing the impetus for movement of the gas and liquid mix from the device into the space to be treated. It may also be possible to have the pressure within the expansion chamber at a pressure lower than that of the treated space, which may aid in the mixing or dispersion of the diffused liquid within the atmosphere within the space.

Within the context of this disclosure, diffusion also generally refers to a process or method of dispersing a liquid without destroying the integrity of the liquid compound. While some degree of reactivity between the gas and the liquid may be desirable, diffusion generally does not change the nature of the liquid, unlike heating or the application of electrical energy into the liquid to diffuse the liquid.

The removable cartridges <NUM>, <NUM> and components thereof described herein may be used with a diffusion device to provide or introduce a pleasant or soothing scent (or some other type of liquid that may be used as an airborne treatment or compound) into the air space of a room or other enclosed space. The particular liquid to be dispensed by the diffusion device is contained within the removable cartridge <NUM>, <NUM>. Other possible types of liquids that may be dispersed may include decontamination agents, insecticides, insect repellents, and many different types of liquids that may be desirably dispersed within an enclosed space. The present disclosure is not limited to a particular type or nature of liquid to be dispersed, but is intended to encompass any desirable airborne liquid treatments that are preferably dispersed within an enclosed space to be effective. The term enclosed space, as used herein, refers to any volume of space within which the atmospheric turnover is sufficiently slow to permit the dispersed liquid to have its desired effect within the space. Larger spaces, such as concert halls, casinos, lobbies, etc., may have one or more openings into the space and still have the desired characteristics to permit treatment with a diffused liquid. Other spaces may be preferably fully enclosed to permit treatment by the selected liquid. In other cases, the liquid used for treatment may preferably be used in a sealed space for maximum effectiveness or for safety reasons. Within the scope of the present disclosure, it is not intended to limit the nature, size or configuration of the space to be treated except as may be appropriate for the liquid used to treat the space and the nature of treatment desired within the space.

A source of pressurized gas <NUM>, <NUM> (<FIG> and <FIG>) may be provided within or in connection with the diffusion device that receives the removable cartridges <NUM>, <NUM>. The source of pressurized gas <NUM>, <NUM> may comprise, for example, a small air compressor or pump, an internal reservoir, or a connection to an external source of pressurized gas. In some embodiments, controls may be configured to permit adjustment of the timing and/or pressure level of the pressurized gas or air generated by the pump or compressor that is ultimately directed into and passes through the cartridge <NUM>, <NUM>. In some instances, the operating pressure may be relatively low, such as, for example, less than about <NUM> psi gauge pressure (<NUM> kPa) or about <NUM> psi gauge pressure (<NUM> kPa). Within the cartridge <NUM>, <NUM>, the pressurized gas is directed to atomize the liquid contained therein and to aid in the dispersion of the atomized liquid into the air space to be treated.

In some instances, it may be desirable to have an indirect route from the point of actual atomization of the liquid and an outlet <NUM>, <NUM> (<FIG> and <FIG>) through which a portion of the atomized particles exit from the cartridge <NUM>, <NUM>. As will be described in greater detail below, embodiments of the removable cartridges <NUM>, <NUM> described herein provide an atomization zone where liquid from the cartridge <NUM>, <NUM> and pressurized gas meet and are mixed. In addition, the cartridges <NUM>, <NUM> may also provide an expansion chamber or chambers within the cartridge <NUM>, <NUM> where the atomized liquid is retained until a portion of the atomized liquid is allowed to exit the cartridge <NUM>, <NUM> and host diffusion device. As described in greater detail elsewhere, the cartridges <NUM>, <NUM> may combine storage of the liquid to be diffused, an atomization structure to transform the liquid into an airborne concentration, an expansion chamber or chambers, and a tortuous path or passage towards the outlet <NUM>, <NUM> of the cartridge <NUM>, <NUM>. Cartridges <NUM>, <NUM> according to the present disclosure may also be used in conjunction with one or more external expansion chambers to further aid in the separation of particle sizes and permit only desirably small particles to be allowed into the space to be treated.

Referring now to <FIG>, one example embodiment of a removable cartridge <NUM> is shown for use with a diffusion device which is configured to treat a space with diffused liquid generated by a flow of pressurized gas moving through the cartridge <NUM>. As shown in <FIG>, the removable cartridge <NUM> may include a housing <NUM> having two or more portions or pieces 110a, 110b coupled together to define a fluid receptacle having an internal cavity <NUM>, which is partially filled with liquid <NUM> to be diffused. In some instances, the housing portions or pieces 110a, 110b may be fixedly coupled together to prevent non-destructive disassembly of the removable cartridge <NUM>, making it effectively tamperproof. This may be desirable to prevent users from refilling and reusing a spent cartridge that may be ineffective or less effective in treating the space due to fouling or build-up of residue within the cartridge <NUM> from prior use. As an example, and with reference to <FIG>, the housing portion or pieces 110a, 110b, may be provided with interlocking structures <NUM> that snap or otherwise couple together in a manner that prevents non-destructive disassembly of the housing <NUM>, and hence cartridge <NUM>. A seal <NUM>, such as an o-ring seal or other sealing device, may be provided between the housing portions or pieces 110a, 110b near the interlocking structures <NUM> to provide a liquid tight seal when the housing <NUM> is assembled. In this manner, the liquid <NUM> to be diffused may be prevented from leaking from the housing <NUM> at an interface between the housing portions or pieces 110a, <NUM>0b. Upon depletion of the liquid <NUM>, the cartridge <NUM> may be readily removed and replaced with a like cartridge <NUM> for continued treatment of the environment surrounding the diffusion device, and the depleted cartridge <NUM> may be discarded as an intact unit or collected for refurbishment purposes.

With reference to <FIG>, the housing <NUM> of the cartridge <NUM> may include an upper housing portion 110a and a lower housing portion 110b fixedly coupled together. A cartridge inlet <NUM> may be provided at a bottom end of the lower housing portion 110b to receive a flow of pressurized gas during operation and a cartridge outlet <NUM> may be provided in the upper housing portion 110a for discharging diffused liquid generated by the cartridge <NUM> during operation. The cartridge inlet <NUM> and the cartridge outlet <NUM> may be aligned along a central axis A defined by the housing <NUM>. The housing <NUM> may be rotationally symmetric about the central axis A. For example, as shown in <FIG>, the housing <NUM> may resemble an urn or similar receptacle that is rotationally symmetric about the central axis A. In other instances, the housing <NUM> may be asymmetrically shaped and the cartridge inlet <NUM> and cartridge outlet <NUM> may not be aligned vertically along a common axis. Respective caps or plugs <NUM>, <NUM> may be provided to temporarily close the cartridge inlet <NUM> and cartridge outlet <NUM> during storage, transport or the like to prevent fouling or contamination of the cartridge <NUM> or possible leakage of the liquid <NUM> retained therein.

Internal components and structures of the cartridge <NUM> and related functionality will now be described with reference to <FIG>. According to the illustrated embodiment of the cartridge <NUM>, the internal components and structures provide, among other things, a flow path through the cartridge <NUM> from the cartridge inlet <NUM> to the cartridge outlet <NUM>, as represented by the arrows labeled 130a-<NUM>. When installed in a host diffusion device, the cartridge inlet <NUM> is coupled a source of pressurized gas <NUM> such that the gas may be periodically forced through the cartridge <NUM> as generally represented by the arrows labeled 130a-<NUM> to combine with the liquid <NUM> and to exit as a gas-liquid mixture comprising particularly small liquid particles carried by the gas, referred to generally herein as a diffused liquid.

As shown in <FIG>, the pressurized gas enters the cartridge <NUM> through the cartridge inlet <NUM> at a bottom end of the housing <NUM> and then flows through a diffusion head <NUM> provided within the housing <NUM>, which includes a venturi device <NUM> for drawing the retained liquid <NUM> into the moving gas stream, and a cartridge insert <NUM> before exiting the cartridge <NUM> through the cartridge outlet <NUM>. More particularly, the pressurized gas enters the cartridge <NUM> through the cartridge inlet <NUM> at a bottom end of the housing <NUM>, as represented by the arrow label 130a, and then flows upwardly through a gas supply conduit <NUM> defined by an interior surface <NUM> of a lower portion <NUM> of the diffusion head <NUM>, as represented by the arrow labeled 130b. The gas then flows through the venturi device <NUM> drawing in liquid <NUM> from a fluid reservoir surrounding the lower portion <NUM> of the diffusion head <NUM> within the internal housing cavity <NUM> of the housing <NUM> to create a gas-liquid mixture comprising atomized liquid (also referred to herein as diffused liquid) that is discharged into an expansion chamber <NUM> provided by an upper portion <NUM> of the diffusion head <NUM>, as represented by the arrow labeled 130c. The diffused liquid is then directed toward an impact structure or surface <NUM> located opposite the venturi device <NUM> wherein at least some of the diffused liquid impacts and collects on the impact structure or surface <NUM> and is routed back to any remaining fluid <NUM> in the fluid reservoir to be reintroduced into the gas stream by the venturi device <NUM>. At least some other of the diffused liquid is redirected to flow down around bulkhead portions <NUM> of the diffusion head <NUM> and to pass through passageways <NUM> in the diffusion head <NUM> leading to a portion of the internal cavity <NUM> of the housing above the fluid level L of liquid <NUM> in the cartridge <NUM>, as represented by the arrows labeled 130d and 130e. From there, some of the diffused liquid may collect on the exposed interior surfaces of the housing <NUM> or other internal structures of the cartridge <NUM>, or otherwise precipitate out of the gas and atomized liquid, and rejoin the liquid <NUM> in the fluid reservoir to be reintroduced into the gas stream by the venturi device <NUM>. Some other of the diffused liquid may be propelled into the cartridge insert <NUM> via an inlet <NUM> thereof, as represented by the arrow labeled 130f. From the inlet <NUM> of the insert <NUM>, the diffused liquid proceeds along a tortuous passage through the cartridge insert <NUM>, as represented by the arrows labeled <NUM>, before passing through an outlet passageway <NUM> in the housing <NUM> that leads to the cartridge outlet <NUM> to be discharged from the cartridge <NUM>, as represented by the arrow labeled <NUM>. In making this convoluted journey from the expansion chamber <NUM> to the cartridge outlet <NUM>, the liquid particle size distribution of the diffused liquid is refined such that only particularly fine particles are successfully discharged from the cartridge <NUM> with relatively larger particles collecting on one or more surfaces of the internal structures and components of the cartridge <NUM>, or otherwise precipitating out of the gas, for rejoinder with remaining liquid <NUM> in the liquid reservoir for reintroduction into the gas stream passing through the venturi device <NUM>.

Further details of the diffusion head <NUM> and cartridge insert <NUM> will now be discussed with reference to <FIG>. As shown in <FIG>, the diffusion head <NUM> may include a unitary diffusion head body <NUM> including an upstream or lower portion <NUM> and a downstream or upper portion <NUM>. For example, in some instances the diffusion head <NUM> may be molded or otherwise formed as a unitary piece of material, such as a suitable plastic or polymeric material. The lower portion <NUM> of the diffusion head <NUM> may be sized and shaped to nest closely with a corresponding portion of the housing <NUM>, as shown in <FIG>, or to otherwise interface with the housing <NUM>, and may be fixedly joined to the housing <NUM> via spin welding, ultrasonic welding other joining processes to create a liquid-tight seal between the housing <NUM> and the lower portion <NUM> of the diffusion head <NUM>. In some instances, such as the example embodiment of the diffusion head <NUM> shown in <FIG>, the lower portion <NUM> of the diffusion head body <NUM> may include a flange <NUM> or other feature, such as a step, projection, tab, indent, or groove, that interfaces with the housing <NUM> to assist in fitment and joining of the components.

With continued reference to <FIG>, the lower portion <NUM> of the diffusion head body <NUM> includes an interior surface <NUM> that defines the gas supply conduit <NUM> that leads from the cartridge inlet <NUM> at a bottom end of the cartridge <NUM> toward the venturi device <NUM>. The gas supply conduit <NUM> may also be partially defined by a divider portion <NUM> of the diffusion head body <NUM> which divides the upper portion <NUM> of the diffusion head <NUM> from the lower portion <NUM>. The divider portion <NUM> separates and isolates the gas supply conduit <NUM> from the expansion chamber <NUM> with the exception of a flow passage <NUM> through the venturi device <NUM> which provides the only fluid communication between the gas supply conduit <NUM> and the expansion chamber <NUM>.

With reference to <FIG> and <FIG>, the liquid <NUM> to be diffused may surround the lower portion <NUM> of the diffusion head <NUM> such that gas enters the cartridge <NUM> from a bottom <NUM> of the cartridge <NUM> and passes through a region of the diffusion head <NUM> surrounded by the liquid <NUM> before reaching the venturi device <NUM>. At the venturi device <NUM>, the gas is accelerated via the flow passage <NUM> and a lower pressure zone is created which draws the liquid <NUM> to be diffused through a suction tube <NUM> that provides fluid communication between the liquid reservoir that surrounds the lower portion <NUM> of the diffusion head <NUM> and the venturi device <NUM>. The initial volume of liquid <NUM> supplied with the cartridge <NUM> preferably does not fill the entire interior cavity <NUM> of the housing <NUM>, but rather defines a fluid level L that is below the venturi device <NUM>.

As shown in <FIG>, the diffusion head <NUM> may include a tube receiving passage <NUM> in the divider portion <NUM> of the diffusion head body <NUM> to receive one end of the suction tube <NUM> and to position an outlet of the suction tube <NUM> in fluid communication with the flow passage <NUM> of the venturi device <NUM> such that the liquid <NUM> may be drawn into the path of the pressurized gas as it is accelerated via the flow passage <NUM> of the venturi device <NUM>. The flow passage <NUM> of the venturi device <NUM> may comprise a convergent entrance, a narrow throat, a side port for introduction of the liquid, and a divergent outlet which are configured to accelerate the flow of gas, draw in the liquid <NUM> through the side port and discharge diffused liquid into the downstream expansion chamber <NUM> provided by the upper portion <NUM> of the diffuser head <NUM>. The size and shape of the flow passage <NUM> may be configured based on characteristics of the gas flow, the geometry of the gas supply conduit <NUM> and the volume and velocity of gas required to effectively draw liquid <NUM> up the suction tube <NUM> and atomize liquid <NUM> in the venturi device <NUM>.

With continued reference to <FIG>, the diffused liquid may be discharged from the venturi device <NUM> with sufficient force to cause at least some of the atomized liquid particles suspended in the gas, particularly the relatively larger particles, to impinge upon and collect on the underside of the cartridge insert <NUM>, which is provided opposite the venturi device <NUM> to serve as an impact structure, preferably a concave impact structure. More particularly, the insert <NUM> may include a lower portion having an indentation or depression <NUM> that includes an impact surface <NUM> to be impinged upon by the diffused liquid generated by the venturi device <NUM> during operation. In some instances, the impact surface <NUM> may be concave and may diverge in a downward direction to direct liquid condensed or collected thereon radially outward and downward. In some embodiments, the impact surface <NUM> may be a conical or frustoconical surface. Liquid collecting on the underside of the insert <NUM> may drip or run down onto the divider portion <NUM> of the diffusion head <NUM> and drain to the liquid reservoir via the passageways <NUM> provided in the upper portion <NUM> of the diffusion head <NUM>, which in some embodiments may provide the only fluid communication between the expansion chamber <NUM> and the internal cavity <NUM> of the housing <NUM> external of the diffusion head <NUM>.

As shown in <FIG>, the insert <NUM> is positioned above of the diffusion head <NUM> and includes a body <NUM>, an inlet <NUM> provided in the body <NUM> to receive the diffused liquid generated within the cartridge <NUM> during operation of the liquid diffusion device, an outlet zone <NUM> defined at least in part by the body <NUM> through which to discharge the diffused liquid toward the external environment, and a tortuous passage <NUM> extending between the inlet <NUM> and the outlet zone <NUM> to aid in further reducing an average liquid particle size of the diffused liquid as the diffused liquid moves through the tortuous passage <NUM> during operation. The inlet <NUM> may be located at a periphery <NUM> of the body <NUM>, the outlet zone <NUM> may be located at a central region <NUM> of the body <NUM>, and the tortuous passage <NUM> may spiral or otherwise extend in a convoluted manner between the inlet <NUM> and the outlet zone <NUM>. The tortuous passage <NUM> may be at least partially defined by a vertical sidewall <NUM> of the body <NUM>. The sidewall <NUM> may extend from the periphery <NUM> of the body <NUM> into the central region <NUM> of the body <NUM>. A floor <NUM> of the insert <NUM> may be inclined or sloped toward the inlet <NUM> to assist in rerouting liquid that has precipitated out of the gas/diffused liquid mixture or that has otherwise collected on surfaces of the insert <NUM> as the mixture passes through the tortuous passage <NUM> during operation back to rejoin any remaining liquid <NUM> in the internal cavity <NUM> surrounding the lower portion <NUM> of the diffusion head <NUM> to be reintroduced into the gas stream passing through the venturi device <NUM>.

As shown in <FIG>, the tortuous passage <NUM> may be open in an upward direction and may be at least partially capped with a corresponding portion <NUM> of the housing <NUM> when the cartridge <NUM> is assembled to define an aerosol outlet at a remaining uncovered portion at the outlet zone <NUM>. The insert <NUM> may also include a chamfer <NUM> of other feature or structure for interfacing with the housing <NUM> to assist in alignment and fitment of the insert <NUM> within the cartridge <NUM> as the insert <NUM> is sandwiched between the cartridge housing <NUM> and the diffusion head <NUM> in the assembled condition. In the assembled condition, the diffusion head <NUM> and the insert <NUM> extend longitudinally between the lower housing portion 110b and the upper housing portion 110a to define a central core of the cartridge <NUM> that fully traverses the housing <NUM> in a longitudinal direction.

The body <NUM> of the insert <NUM> is preferably formed as a single, unitary piece that includes the tortuous passage <NUM> and is coupled to or otherwise positioned adjacent the upper portion <NUM> of the diffusion head <NUM> to cap the expansion chamber <NUM>. For example, in some instances the insert <NUM> may be molded or otherwise formed as a unitary piece of material, such as a suitable plastic or polymeric material. The upper portion <NUM> of the diffusion head <NUM> and the insert <NUM> may be sized and shaped to nest together. For example, the upper portion <NUM> of the diffusion head <NUM> may include a recess or shelf <NUM> to receive and support the insert <NUM>. In some embodiments, the insert <NUM> may be fixedly joined to the diffusion head <NUM> via spin welding, ultrasonic welding or other joining techniques. Still further, although the diffusion head <NUM> and the insert <NUM> are described herein as two separate components positioned or joined together, it is appreciated that the structures and features of these components may be formed as a single unitary piece via an additive manufacturing process, for example. In other instances, the structures and features of the diffusion head <NUM> and the insert <NUM> may be provided by more than two pieces that are joined or otherwise coupled together. In the particularly advantageous embodiment illustrated in <FIG>, however, the removable cartridge <NUM> consists, or consists essentially, of the cartridge housing <NUM>, the diffusion head <NUM>, the cartridge insert <NUM>, the liquid <NUM> to be diffused, and the conduit or tube <NUM> that extends from a side of the venturi device <NUM> of the diffusion head <NUM> to a lower region of the internal housing cavity <NUM> to enable the liquid <NUM> contained therein to be drawn into the path of the pressurized gas as it moves through the venturi device <NUM> during operation.

According to the illustrated embodiment, the tortuous passage <NUM> is helical and makes at least one full revolution about the central axis A. It is appreciated, however, that the tortuous passage <NUM> may take on a variety of different forms. For example, the tortuous passage <NUM> may include a curvilinear path that at least partially encircles the central axis A as it moves from the inlet <NUM> toward the outlet zone <NUM>. In other instances, the tortuous passage <NUM> may include a path with a plurality of straight segments angled relative to each other to provide a number of turns. In still other instances, the tortuous passage <NUM> may include a path that combines linear and non-linear path segments. The cross-sectional shape of the tortuous passage <NUM> may also vary along the tortuous passage <NUM>. For example, a cross-sectional profile of at least a portion of the tortuous passage <NUM> may narrow in a downstream direction, that is in a direction from the inlet <NUM> toward the outlet zone <NUM>. This narrowing of the tortuous passage <NUM> may further assist in refining the composition of the diffused liquid to include only the finest of liquid particles.

Irrespective of particular configuration, the tortuous passage <NUM> follows a non-linear path that, among other things, assists in preventing liquid <NUM> from leaking from the cartridge <NUM> when the cartridge <NUM> is upended. For example, if the cartridge <NUM> is temporarily held upside down, the tortuous passage <NUM> will assist in slowing the progression of liquid <NUM> within the cartridge <NUM> toward the outlet zone <NUM> and hence the outlet <NUM> of the cartridge <NUM>. In this manner, the cartridge <NUM> can be subsequently righted without the loss of fluid. Moreover, in the event the cartridge <NUM> is upended and comes to rest on its side, the cartridge <NUM> is configured such that the volume of liquid <NUM> supplied with the cartridge <NUM> will not rise above the central axis A of the cartridge <NUM>, as illustrated in <FIG>. In this manner, the tortuous passage <NUM> will prevent the liquid <NUM> from spilling out of the outlet <NUM> as the liquid <NUM> will be unable to move through the entirety of the tortuous passage <NUM> as at least a portion of the tortuous passage <NUM> will be located above the fluid level L<NUM> of the liquid <NUM>.

With reference again to <FIG>, it will be appreciated that the housing <NUM> and internal components of the cartridge <NUM> define a plurality of distinct chambers downstream of the venturi device <NUM> through which the diffused liquid sequentially travels before being discharged from the cartridge <NUM> and ultimately into a surrounding environment. More particularly, the upper portion <NUM> of the diffusion head <NUM> and a lower portion of the insert <NUM> define a primary expansion chamber <NUM> immediately above the venturi device <NUM>, a secondary chamber is provided external of the diffusion head <NUM> and the insert <NUM> within internal cavity <NUM> of the housing <NUM> above the fluid level L of the liquid <NUM> to be diffused, and a tertiary chamber is provided by the tortuous passage <NUM> of the insert <NUM>. Passageways or apertures <NUM> in the upper portion <NUM> of the diffusion head <NUM> provide fluid communication between the primary expansion chamber <NUM> and the secondary chamber. The upper portion <NUM> of the diffusion head <NUM> also defines a bulkhead or bulkhead portions <NUM> that impede the diffused liquid generated by the venturi device <NUM> from exiting the primary expansion chamber <NUM> other than through the plurality of passageways or apertures <NUM>. The inlet <NUM> of the insert <NUM> provides fluid communication between the secondary chamber and the tertiary chamber (i.e., the tortuous passage <NUM>). Although only one inlet <NUM> and one tortuous passage <NUM> is shown providing the sole passage for the diffused liquid to exit the cartridge <NUM>, it is appreciated that a plurality of inlets <NUM> may be provide to enable diffused liquid to enter one or more tortuous passages leading to the outlet <NUM> of the cartridge <NUM>. The distinct chambers described above (i.e., the primary expansion chamber, the secondary chamber and the tertiary chamber) collectively assist in refining the composition of the diffused liquid to include only the finest liquid particles as the diffused liquid moves sequentially through the chambers during operation. For instance, by the time the gas/diffused liquid mixture exits from cartridge <NUM>, there has been some residence time in each of the distinct chambers to permit undesirably large liquid particles or droplets to precipitate or otherwise separate from the mixture and be returned to the liquid reservoir within the internal cavity <NUM> of the housing <NUM> external the diffusion head <NUM> for later atomization and dispersion. In this manner, the removable cartridge <NUM> and components thereof may provide a cartridge solution for a diffusion device which has an efficient form factor that is particularly effective at treating spaces with diffused liquid having extremely small liquid particles.

Referring now to <FIG>, another example embodiment of a removable cartridge <NUM> is shown for use with a diffusion device which is configured to treat a space with diffused liquid generated by a flow of pressurized gas moving through the cartridge <NUM>. As shown in <FIG>, the removable cartridge <NUM> may include a housing <NUM> having two or more portions or pieces <NUM>0a, 210b coupled together to define, among other things, a fluid receptacle having an internal cavity <NUM> partially filled with liquid <NUM> to be diffused. In some instances, the housing portions or pieces <NUM>0a, 210b may be fixedly coupled together to prevent non-destructive disassembly of the removable cartridge <NUM>, making it effectively tamperproof. This may be desirable to prevent users from refilling and reusing a spent cartridge that may be ineffective or less effective in treating the space due to fouling or build-up of residue within the cartridge <NUM> from prior use. As an example, and with reference to <FIG>, the housing portion or pieces <NUM>0a, <NUM>0b, may be provided with interlocking structures <NUM> that snap or otherwise couple together in a manner that prevents non-destructive disassembly of the housing <NUM>, and hence cartridge <NUM>. A seal <NUM>, such as an o-ring seal or other sealing device, may be provided between the housing portions or pieces 210a, 210b near the interlocking structures <NUM> to provide a liquid tight seal when the housing <NUM> is assembled. In this manner, the liquid <NUM> to be diffused may be prevented from leaking from the housing <NUM> at an interface between the housing portions or pieces 210a, 210b. Upon depletion of the liquid <NUM>, the cartridge <NUM> may be readily removed and replaced with a like cartridge <NUM> for continued treatment of the environment surrounding the diffusion device, and the depleted cartridge <NUM> may be discarded as an intact unit or collected for refurbishment purposes.

With reference to <FIG>, the housing <NUM> of the cartridge <NUM> may include an upper housing portion 210a and a lower housing portion 210b fixedly coupled together. A cartridge inlet <NUM> may be provided at a bottom end of the lower housing portion 210b to receive a flow of pressurized gas during operation and a cartridge outlet <NUM> may be provided in the upper housing portion 210a for discharging diffused liquid generated by the cartridge <NUM> during operation. The cartridge inlet <NUM> and the cartridge outlet <NUM> may be aligned along a central axis A<NUM> defined by the housing <NUM>. The housing <NUM> may be rotationally symmetric about the central axis A<NUM>. For example, as shown in <FIG>, the housing <NUM> may resemble a generally cylindrical vessel or similar receptacle that is rotationally symmetric about the central axis A<NUM>. In other instances, the housing <NUM> may be asymmetrically shaped and the cartridge inlet <NUM> and cartridge outlet <NUM> may not be aligned vertically along a common axis. Respective caps or plugs (not shown) may be provided to temporarily close the cartridge inlet <NUM> and cartridge outlet <NUM> during storage, transport or the like to prevent fouling or contamination of the cartridge <NUM> or possible leakage of the liquid <NUM> retained therein.

Internal components and structures of the cartridge <NUM> and related functionality will now be described with reference to <FIG>. According to the illustrated embodiment of the cartridge <NUM>, the internal components and structures provide, among other things, a flow path through the cartridge <NUM> from the cartridge inlet <NUM> to the cartridge outlet <NUM>, as represented by the arrows labeled 230a-<NUM>. When installed in a host diffusion device, the cartridge inlet <NUM> is coupled a source of pressurized gas <NUM> such that the gas may be periodically forced through the cartridge <NUM> as generally represented by the arrows labeled 230a-<NUM> to combine with the liquid <NUM> and to exit as a gas-liquid mixture comprising particularly small liquid particles carried by the gas, referred to generally herein as a diffused liquid.

As shown in <FIG>, the pressurized gas enters the cartridge <NUM> through the cartridge inlet <NUM> at a bottom end of the housing <NUM> and then flows through a diffusion head <NUM> provided within the housing <NUM>, which includes a venturi device <NUM> for drawing the retained liquid <NUM> into the moving gas stream, and a cartridge insert <NUM> before exiting the cartridge <NUM> through the cartridge outlet <NUM>. More particularly, the pressurized gas enters the cartridge <NUM> through the cartridge inlet <NUM> at a bottom end of the housing <NUM>, as represented by the arrow label 230a, and then flows upwardly through a gas supply conduit <NUM> defined by an interior surface <NUM> of a lower portion <NUM> of the diffusion head <NUM>, as represented by the arrow labeled 230b. The gas then flows through the venturi device <NUM> drawing in liquid <NUM> from a fluid reservoir surrounding the lower portion <NUM> of the diffusion head <NUM> within the internal housing cavity <NUM> of the housing <NUM> to create a gas-liquid mixture comprising atomized liquid (also referred to herein as diffused liquid) that is discharged into an expansion chamber <NUM> provided by an upper portion <NUM> of the diffusion head <NUM>, as represented by the arrow labeled 230c. The diffused liquid is then directed toward an impact structure or surface <NUM> located opposite the venturi device <NUM> wherein at least some of the diffused liquid impacts and collects on the impact structure or surface <NUM> and is routed back to any remaining fluid <NUM> in the fluid reservoir to be reintroduced into the gas stream by the venturi device <NUM>. At least some other of the diffused liquid is redirected to flow down around bulkhead portions <NUM> of the diffusion head <NUM> and to pass through passageways <NUM> in the diffusion head <NUM> leading to a portion of the internal cavity <NUM> of the housing above the fluid level L<NUM> of liquid <NUM> in the cartridge <NUM>, as represented by the arrows labeled 230d and 230e. From there, some of the diffused liquid may collect on the exposed interior surfaces of the housing <NUM> or other internal structures of the cartridge <NUM>, or otherwise precipitate out of the gas and atomized liquid, and rejoin the liquid <NUM> in the fluid reservoir to be reintroduced into the gas stream by the venturi device <NUM>. Some other of the diffused liquid may be propelled into the cartridge insert <NUM> via an inlet <NUM> thereof, as represented by the arrow labeled 230f. From the inlet <NUM> of the insert <NUM>, the diffused liquid proceeds along a tortuous passage <NUM> (see <FIG>) through the cartridge insert <NUM>, as represented by the arrows labeled <NUM>, before passing through an outlet passageway <NUM> in the housing <NUM> that leads to the cartridge outlet <NUM> to be discharged from the cartridge <NUM>, as represented by the arrow labeled <NUM>. In making this convoluted journey from the expansion chamber <NUM> to the cartridge outlet <NUM>, the liquid particle size distribution of the diffused liquid is refined such that only particularly fine particles are successfully discharged from the cartridge <NUM> with relatively larger particles collecting on one or more surfaces of the internal structures and components of the cartridge <NUM>, or otherwise precipitating out of the gas, for rejoinder with remaining liquid <NUM> in the liquid reservoir for reintroduction into the gas stream passing through the venturi device <NUM>.

As shown in <FIG>, the diffusion head <NUM> may include a unitary diffusion head body <NUM> including an upstream or lower portion <NUM> and a downstream or upper portion <NUM>. For example, in some instances the diffusion head <NUM> may be molded or otherwise formed as a unitary piece of material, such as a suitable plastic or polymeric material. The lower portion <NUM> of the diffusion head <NUM> may be sized and shaped to nest closely with a corresponding portion of the housing <NUM>, as shown in <FIG>, or to otherwise interface with the housing <NUM>, and may be fixedly joined to the housing <NUM> via spin welding, ultrasonic welding other joining processes to create a liquid-tight seal between the housing <NUM> and the lower portion <NUM> of the diffusion head <NUM>. In some instances, such as the example embodiment of the diffusion head <NUM> shown in <FIG>, the lower portion <NUM> of the diffusion head body <NUM> may include a flange <NUM> or other feature, such as a step, projection, tab, indent, or groove, that interfaces with the housing <NUM> to assist in fitment and joining of the components.

With continued reference to <FIG>, the liquid <NUM> to be diffused may surround the lower portion <NUM> of the diffusion head <NUM> such that gas enters the cartridge <NUM> from a bottom <NUM> of the cartridge <NUM> and passes through a region of the diffusion head <NUM> surrounded by the liquid <NUM> before reaching the venturi device <NUM>. At the venturi device <NUM>, the gas is accelerated via the flow passage <NUM> and a lower pressure zone is created which draws the liquid <NUM> to be diffused through a suction tube <NUM> that provides fluid communication between the liquid reservoir that surrounds the lower portion <NUM> of the diffusion head <NUM> and the venturi device <NUM>. The initial volume of liquid <NUM> supplied with the cartridge <NUM> preferably does not fill the entire interior cavity <NUM> of the housing <NUM>, but rather defines a fluid level L<NUM> that is below the venturi device <NUM>.

With reference to <FIG>, the insert <NUM> is positioned above of the diffusion head <NUM> and includes a body <NUM>, an inlet <NUM> provided in the body <NUM> to receive the diffused liquid generated within the cartridge <NUM> during operation of the liquid diffusion device, an outlet zone <NUM> defined at least in part by the body <NUM> through which to discharge the diffused liquid toward the external environment, and a tortuous passage <NUM> extending between the inlet <NUM> and the outlet zone <NUM> to aid in further reducing an average liquid particle size of the diffused liquid as the diffused liquid moves through the tortuous passage <NUM> during operation. The inlet <NUM> may be located at or near a periphery <NUM> of the body <NUM>, the outlet zone <NUM> may be located at a central region <NUM> of the body <NUM>, and the tortuous passage <NUM> may spiral or otherwise extend in a convoluted manner between the inlet <NUM> and the outlet zone <NUM>. The tortuous passage <NUM> may be at least partially defined by a vertical sidewall <NUM> of the body <NUM>. The sidewall <NUM> may extend from the periphery <NUM> of the body <NUM> into or towards the central region <NUM> of the body <NUM>. A floor <NUM> of the insert <NUM> may be inclined or sloped toward the inlet <NUM> to assist in rerouting liquid that has precipitated out of the gas/diffused liquid mixture or that has otherwise collected on surfaces of the insert <NUM> as the mixture passes through the tortuous passage <NUM> during operation back to rejoin any remaining liquid <NUM> in the internal cavity <NUM> surrounding the lower portion <NUM> of the diffusion head <NUM> to be reintroduced into the gas stream passing through the venturi device <NUM>.

As shown in <FIG> and <FIG>, the tortuous passage <NUM> may be open in an upward direction and may be at least partially capped with a corresponding portion <NUM> of the housing <NUM> when the cartridge <NUM> is fully assembled to define an aerosol outlet at a remaining uncovered portion at the outlet zone <NUM>. The insert <NUM> may be sandwiched between the cartridge housing <NUM> and the diffusion head <NUM> in the assembled condition. In the assembled condition, the diffusion head <NUM> and the insert <NUM> extend longitudinally between the lower housing portion 210b and the upper housing portion 210a to define a central core of the cartridge <NUM> that fully traverses the housing <NUM> in a longitudinal direction.

The body <NUM> of the insert <NUM> is preferably formed as a single, unitary piece that includes the tortuous passage <NUM> and is coupled to or otherwise positioned adjacent the upper portion <NUM> of the diffusion head <NUM> to cap the expansion chamber <NUM>. For example, in some instances the insert <NUM> may be molded or otherwise formed as a unitary piece of material, such as a suitable plastic or polymeric material. The upper portion <NUM> of the diffusion head <NUM> and the insert <NUM> may be sized and shaped to nest together. For example, the upper portion <NUM> of the diffusion head <NUM> may include a recess or shelf to receive and support the insert <NUM>. In other instances, the upper portion <NUM> of the diffusion head <NUM> and the insert <NUM> may abut each other along planar surfaces. In some embodiments, the insert <NUM> may be fixedly joined to the diffusion head <NUM> via spin welding, ultrasonic welding or other joining techniques. Still further, although the diffusion head <NUM> and the insert <NUM> are described herein as two separate components positioned or joined together, it is appreciated that the structures and features of these components may be formed as a single unitary piece via an additive manufacturing process, for example. In other instances, the structures and features of the diffusion head <NUM> and the insert <NUM> may be provided by more than two pieces that are joined or otherwise coupled together. In the particularly advantageous embodiment illustrated in <FIG>, however, the removable cartridge <NUM> consists, or consists essentially, of the cartridge housing <NUM>, the diffusion head <NUM>, the cartridge insert <NUM>, the liquid <NUM> to be diffused, and the conduit or tube <NUM> that extends from a side of the venturi device <NUM> of the diffusion head <NUM> to a lower region of the internal housing cavity <NUM> to enable the liquid <NUM> contained therein to be drawn into the path of the pressurized gas as it moves through the venturi device <NUM> during operation.

According to the illustrated embodiment, the tortuous passage <NUM> is helical and makes at least two full revolutions about the central axis A<NUM>. It is appreciated, however, that the tortuous passage <NUM> may take on a variety of different forms. For example, the tortuous passage <NUM> may include a curvilinear path that at least partially encircles the central axis A<NUM> as it moves from the inlet <NUM> toward the outlet zone <NUM>. In other instances, the tortuous passage <NUM> may include a path with a plurality of straight segments angled relative to each other to provide a number of turns. In still other instances, the tortuous passage <NUM> may include a path that combines linear and non-linear path segments. The cross-sectional shape of the tortuous passage <NUM> may also vary along the tortuous passage <NUM>. For example, a cross-sectional profile of at least a portion of the tortuous passage <NUM> may narrow in a downstream direction, that is in a direction from the inlet <NUM> toward the outlet zone <NUM>. This narrowing of the tortuous passage <NUM> may further assist in refining the composition of the diffused liquid to include only the finest of liquid particles.

Irrespective of particular configuration, the tortuous passage <NUM> follows a non-linear path that, among other things, assists in preventing liquid <NUM> from leaking from the cartridge <NUM> when the cartridge <NUM> is upended. For example, if the cartridge <NUM> is temporarily held upside down, the tortuous passage <NUM> will assist in slowing the progression of liquid <NUM> within the cartridge <NUM> toward the outlet zone <NUM> and hence the outlet <NUM> of the cartridge <NUM>. In this manner, the cartridge <NUM> can be subsequently righted without the loss of fluid. Moreover, in the event the cartridge <NUM> is upended and comes to rest on its side, the cartridge <NUM> is configured such that the volume of liquid <NUM> supplied with the cartridge <NUM> will not rise above the central axis A<NUM> of the cartridge <NUM>. In this manner, the tortuous passage <NUM> will prevent the liquid <NUM> from spilling out of the outlet <NUM> as the liquid <NUM> will be unable to move through the entirety of the tortuous passage <NUM> as at least a portion of the tortuous passage <NUM> will be located above the fluid level of the liquid <NUM>.

With reference again to <FIG>, it will be appreciated that the housing <NUM> and internal components of the cartridge <NUM> define a plurality of distinct chambers downstream of the venturi device <NUM> through which the diffused liquid sequentially travels before being discharged from the cartridge <NUM> and ultimately into a surrounding environment. More particularly, the upper portion <NUM> of the diffusion head <NUM> and a lower portion of the insert <NUM> define a primary expansion chamber <NUM> immediately above the venturi device <NUM>, a secondary chamber is provided external of the diffusion head <NUM> and the insert <NUM> within internal cavity <NUM> of the housing <NUM> above the fluid level L<NUM> of the liquid <NUM> to be diffused, and a tertiary chamber is provided by the tortuous passage <NUM> of the insert <NUM>. Passageways or apertures <NUM> in the upper portion <NUM> of the diffusion head <NUM> provide fluid communication between the primary expansion chamber <NUM> and the secondary chamber. The upper portion <NUM> of the diffusion head <NUM> also defines a bulkhead or bulkhead portions <NUM> that impede the diffused liquid generated by the venturi device <NUM> from exiting the primary expansion chamber <NUM> other than through the plurality of passageways or apertures <NUM>. The inlet <NUM> of the insert <NUM> provides fluid communication between the secondary chamber and the tertiary chamber (i.e., the tortuous passage <NUM>). Although only one inlet <NUM> and one tortuous passage <NUM> is shown providing the sole passage for the diffused liquid to exit the cartridge <NUM>, it is appreciated that a plurality of inlets <NUM> may be provide to enable diffused liquid to enter one or more tortuous passages leading to the outlet <NUM> of the cartridge <NUM>. The distinct chambers described above (i.e., the primary expansion chamber, the secondary chamber and the tertiary chamber) collectively assist in refining the composition of the diffused liquid to include only the finest liquid particles as the diffused liquid moves sequentially through the chambers during operation. For instance, by the time the gas/diffused liquid mixture exits from cartridge <NUM>, there has been some residence time in each of the distinct chambers to permit undesirably large liquid particles or droplets to precipitate or otherwise separate from the mixture and be returned to the liquid reservoir within the internal cavity <NUM> of the housing <NUM> external the diffusion head <NUM> for later atomization and dispersion. In this manner, the removable cartridge <NUM> and components thereof may provide a cartridge solution for a diffusion device which has an efficient form factor that is particularly effective at treating spaces with diffused liquid having extremely small liquid particles.

In the present disclosure, the outlet <NUM>, <NUM> of the cartridge <NUM>, <NUM> and/or outlet of a host diffusion device have permitted atomized liquid generated within the cartridge <NUM>, <NUM> to flow directly into a space to be treated. However, the cartridge <NUM>, <NUM> could alternatively direct diffused liquid into an air transport or distribution system instead. The air transport system might include ductwork or other avenues that would permit the diffused liquid to be dispersed into a remotely located space or a plurality of remotely located spaces. Thus, cartridge <NUM>, <NUM> could be used to diffuse and disperse liquid throughout an entire building, for example, through the existing HVAC conduits.

It is also anticipated that cartridge <NUM> might be adapted to mount directly to a fitting on a conduit or source of compressed gas without the need for mounting within or as part of a host diffusion device. Such a fitting might permit cartridge <NUM>, <NUM> to be positioned to treat air within a single enclosed space or may be used to treat air flowing through an air transport system and treat a plurality of spaces. Alternatively, a plurality of like cartridges <NUM>, <NUM> might be used to treat individual spaces but may be linked to the same gas source. The source of compressed gas could then be controlled centrally for all of the spaces treated without the need for or provision of local controls for each treated space. Or each space could have a valve for controlling the flow of gas through the cartridge <NUM>, <NUM> and thus the strength or intensity of the treatment within a particular space. Such local control valves could be then permit the same or similar cartridges <NUM>, <NUM> to be used in conjunction with a common gas source to treat a plurality of different sized or configured spaces.

Claim 1:
A cartridge (<NUM>, <NUM>) for use with a liquid diffusing device, the cartridge (<NUM>, <NUM>) comprising:
a cartridge housing (110a, 110b, 210a, 210b) defining an internal housing cavity (<NUM>, <NUM>) partially filled with a liquid (<NUM>) to be diffused;
a diffusion head (<NUM>, <NUM>) positioned within the internal housing cavity (<NUM>, <NUM>), the diffusion head (<NUM>, <NUM>) including a venturi device (<NUM>, <NUM>) for generating a diffused liquid from the liquid (<NUM>) contained in the internal housing cavity (<NUM>, <NUM>); and
an insert (<NUM>, <NUM>) positioned downstream of the diffusion head (<NUM>, <NUM>), the insert (<NUM>, <NUM>) including an inlet (<NUM>, <NUM>) to receive the diffused liquid generated by the venturi device (<NUM>, <NUM>), an outlet zone (<NUM>, <NUM>) through which to discharge the diffused liquid toward an external environment, and a tortuous passage (<NUM>, <NUM>) extending between the inlet (<NUM>, <NUM>) and the outlet zone (<NUM>, <NUM>),
characterized in that
the cartridge (<NUM>, <NUM>) is configured to be operated in an upright configuration in which a central axis (A) of the cartridge housing (110a, 110b, 210a, 210b) is oriented in a vertical direction from a bottom end (<NUM>) of the cartridge (<NUM>, <NUM>) to a top end of the cartridge (<NUM>, <NUM>),
the tortuous passage (<NUM>, <NUM>) is at least partially defined by a vertical sidewall of the insert (<NUM>, <NUM>) that extends from a floor (<NUM>, <NUM>) of the insert (<NUM>, <NUM>) toward the top end of cartridge (<NUM>, <NUM>), and
the tortuous passage (<NUM>, <NUM>) follows a non-linear path that assists in preventing liquid (<NUM>) from leaking from the cartridge (<NUM>, <NUM>) when the cartridge (<NUM>, <NUM>) is upended from the upright configuration to an upended configuration such as when the cartridge (<NUM>, <NUM>) is oriented sideways or upside down.