Fog-generating fluid for a fog-generating device

Abstract

A fog-generating fluid containing dissolved nitrous oxide in an amount of at least 25 g / l.

Description

AREA OF INVENTION

[0001] The present invention relates to fog-generating devices, such as fog-generating devices used in security technology. In particular, the present invention relates to fog-generating fluids containing nitrous oxide, containers containing such fog-generating fluids, and fog-generating devices containing such containers. Furthermore, the present invention relates to the use of these fog-generating fluids, the use of such fog-generating devices for protection against intruders, and methods for generating fog. BACKGROUND OF THE INVENTION

[0002] Fog-generating devices are used in numerous applications. They are used in the entertainment industry to create a specific atmosphere or enhance visual lighting effects. They are used in the training of rescue workers and military personnel to simulate fires. They are also used in security systems to disorient intruders and conceal valuables from them.

[0003] A fog-generating device typically produces fog by forcing a fog-generating fluid through a heat exchanger. The fog-generating fluid is usually contained in a reservoir connected to the heat exchanger. At the desired time (fog emission), the fog-generating fluid is forced into the heat exchanger under pressure. Inside the heat exchanger, the fog-generating fluid is converted into a vapor (with joules of energy being transferred in the form of heat) and then expelled through the heat exchanger's outlet. Depending on the atmosphere in which the vapor is expelled, it may expand and / or its temperature drops, causing it to condense into very small liquid droplets. These droplets then float as an aerosol in the atmosphere, forming a fog cloud.

[0004] The fog-generating capacity is crucial for its use as a security device. In the event of a break-in, for example, the fog-generating device should fill the room with fog within seconds. In such a case, valuables are immediately concealed from the intruder's view, and the intruder will quickly attempt to escape by leaving the room. If the fog is generated too slowly, the thief can use the extra seconds to quickly steal some valuables. A pump is typically used to transport the fog-generating fluid from the reservoir to the heat exchanger. In this case, the time required to convert the necessary amount of fog-generating fluid into fog depends on the pump's capacity, that is, its ability to deliver a specific flow rate at a specific pressure within a given time.Fog-generating devices are often powered by standard-voltage batteries, which further limits the capacity of such pumps. Furthermore, high-performance liquid pumps would lead to excessively high product prices. Consequently, the use of pumps to transport the fog-generating fluid from the reservoir to the heat exchanger significantly limits the fog output of these devices.

[0005] Patent WO03001140A1 solves this problem by using partially halogenated hydrocarbons as a propellant in the container holding the fog-generating fluid. When fog is to be generated, a normally closed valve (switch) between the container and the connected heat exchanger is opened. The partially halogenated hydrocarbon gas is generated from the liquid phase by the vapor pressure of the halogenated hydrocarbons, and this pressure forces the fog-generating fluid from the container to the heat exchanger, thereby improving the fog output capacity of the device.

[0006] The use of partially halogenated hydrocarbons as propellants, such as HFC R125, which is used in patent WO03001140A1, offers several advantages. They are chemically, thermally, and corrosively inert to the construction materials and fog-generating fluids used, as well as during fog generation in the heat exchanger. However, partially halogenated hydrocarbons are classified as greenhouse gases with a high potential contribution to global warming (GWP), making the search for alternatives urgent.

[0007] Patent WO2008132113A1 attempts to find a solution to this problem by providing a fog-generating device in which compressed gas is used as a propellant to drive fog-generating fluid from a container to a heat exchanger. To reduce the greenhouse effect, patent WO2008132113A1 proposes the use of alternative compressed gases to drive the remaining fog-generating fluid out of the heat exchanger (e.g., ambient air, nitrogen) and / or as propellants (inert gas, such as nitrogen; noble gas, such as helium, neon, or argon; noble gas mixtures; mixtures of inert and noble gases).

[0008] Patent EP2860486A1 describes an alternative device for generating fog in which the propellant is separated from the fog-generating fluid by a movable wall.

[0009] While these fog-generating devices function well, there is a need for smaller units that are easier to install in available, and sometimes confined, spaces. Furthermore, there is also a significant need for devices of the same size that can handle a larger volume of fog-generating fluid, as these would allow larger rooms and warehouses to be filled with fog to deter and stop break-in attempts. At the same time, reducing energy consumption in fog generation would offer a dual benefit. Firstly, it would reduce the economic and environmental impact. Secondly, it is crucial for security systems that they can continue operating for as long as possible after a (deliberate or accidental) power outage.While the insulation and other properties of the heat exchanger can keep the heat exchanger at a sufficiently high temperature for a certain period of time, lower energy consumption for the evaporation of the fog-generating fluid compared to state-of-the-art devices would allow more fog to be produced under the same conditions. SUMMARY OF THE INVENTION

[0010] The inventor surprisingly discovered that using dissolved nitrous oxide in the fog-generating fluid solved the problems of the prior art. This appears to make it possible to use more fog-generating fluid per container volume while simultaneously reducing the energy required for vaporizing the fog-generating fluid.

[0011] Accordingly, a particular aspect of the invention consists in providing a fog-generating fluid containing dissolved nitrous oxide. The fog-generating fluid may also contain a polyol, preferably a glycol, particularly preferably dipropylene glycol, and optionally triethylene glycol. In a further embodiment, the fog-generating fluid contains glycol in an amount of 50 to 90% by volume. In another embodiment, the fog-generating fluid contains water in an amount of 5 to 50% by volume. In a preferred embodiment, the fog-generating fluid consists of a polyol, which in this document is also referred to as a polyol-containing fog-generating fluid.

[0012] In a particular embodiment, the fog-generating fluid contains dissolved nitrous oxide in an amount of at least 25 g / l, preferably at least 30 g / l, more preferably at least 35 g / l, and most preferably at least 40 g / l. The fog-generating fluid can be saturated with the dissolved nitrous oxide. In a further embodiment, the fog-generating fluid comprises glycol, such as dipropylene glycol and optionally triethylene glycol, in an amount of 50 to 90 vol%, water in an amount of 5 to 50 vol%, and dissolved nitrous oxide in an amount of at least 35 g / l.

[0013] The present invention further provides a housing containing the fog-generating fluid according to the invention. Accordingly, the present invention also provides a housing containing the fog-generating fluid according to the invention, which can be connected to a heat exchanger of a fog-generating device. The housing preferably includes a valve which, in the closed position, prevents the fog-generating fluid from flowing out of the housing.

[0014] In a particular embodiment, the fog-generating fluid is present in the housing at a pressure of at least 10 bar.

[0015] The housing preferably contains a fog-generating fluid comprising (dipropylene and optionally triethylene) glycol in an amount of 50 to 90 vol%, water in an amount of 5 to 15 vol% and dissolved nitrous oxide in an amount of at least 35 g / l.

[0016] The present invention further provides a fog-generating device comprising a fog-generating fluid as described herein. In particular, the invention provides a fog-generating device comprising a heat exchanger and a housing as described herein, wherein dissolved nitrous oxide drives the fog-generating fluid from the housing to the heat exchanger. More specifically, the invention provides a fog-generating device comprising a heat exchanger and a housing containing a fog-generating fluid as described herein, wherein dissolved nitrous oxide drives the fog-generating fluid from the housing to the heat exchanger.

[0017] In a particular embodiment, the fog-generating device maintains a pressure between 8 bar and 30 bar in the housing until 80% or more of the fog-generating fluid has been driven from the housing to the heat exchanger, wherein the fog-generating fluid is preferably driven from the housing at a flow rate between 10 ml / s and 20 ml / s.

[0018] The present invention further provides for the use of nitrous oxide dissolved in a fog-generating fluid to drive the fog-generating fluid from a housing to a heat exchanger in a fog-generating device.

[0019] In a preferred embodiment, the fog-generating fluids, housings and devices described herein are used to generate fog for protection against intruders and / or physical threats from persons.

[0020] In another embodiment, the present invention provides a method for generating fog, the method comprising: (a) Provision of the housing described herein, wherein the housing is connected to a heat exchanger; (b) Use of nitrous oxide dissolved in the fog-generating fluid to drive the fog-generating fluid from the housing into the heat exchanger; and (c) Generation of fog by heating the fog-generating fluid in the heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS Fig. shows a cross-sectional view of a housing containing a fog-generating fluid and nitrous oxide (N2O) according to the invention. Fig. shows a cross-section through a housing containing a fog-generating fluid and pentafluoroethane (HFC125) according to the current state of the art, wherein the HFC is in its liquid phase in the container under its own vapor pressure.

[0021] The drawings are schematic only and not complete. Some elements may have been enlarged for illustrative purposes and are not shown to scale. The dimensions and relative measurements do not correspond to the actual practical embodiments of the invention.

[0022] In the various drawings, the same reference symbols refer to identical or analogous elements. DETAILED DESCRIPTION OF THE INVENTION

[0023] The present invention relates to a fog-generating fluid containing dissolved nitrous oxide; a housing containing this fog-generating fluid; a fog-generating device containing this housing; a method for generating fog; and a use of the described products.

[0024] Particular and preferred aspects of the invention are set forth in the attached independent and dependent claims. Features from the dependent claims may optionally be combined with features from the independent claims and with features from other dependent claims, not only in the manner expressly stated in the claims.

[0025] These and other aspects of the invention will become apparent and be explained from the embodiment(s) described above and below.

[0026] The present invention is described with reference to certain embodiments and with reference to certain drawings; however, it is not limited to these, but is defined only by the claims.

[0027] The terms "bottom", "top", "upwards", "downwards", "high", "low", "horizontal", "vertical", etc. are used in the description and in the claims for descriptive purposes and not necessarily to describe relative positions. It is understood that the terms used in this way are interchangeable under suitable circumstances and that the embodiments of the invention described herein may also function in orientations other than those described or illustrated here.

[0028] Whenever reference is made to “an embodiment” in this patent description, this means that a particular property, structure, or feature described in connection with the embodiment is part of at least one embodiment of the present invention. The phrase “in an embodiment,” which appears in several places in this patent description, does not necessarily refer to the same embodiment each time, but it may. Furthermore, the specific properties, structures, or features may be combined in any suitable manner in one or more embodiments, as is obvious to someone with normal technical knowledge from this disclosure.

[0029] Accordingly, it should be clear that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped into a single embodiment, figure, or description thereof in order to streamline the disclosure and aid in understanding one or more of the various inventive aspects. However, it should not be inferred from this form of disclosure that the claimed invention requires more features than are expressly stated in the individual claims. As the following claims demonstrate, inventive aspects are more likely to be found in fewer than all features of a single previously disclosed embodiment. The claims following the detailed description are therefore hereby expressly incorporated into this detailed description, each claim standing alone as a separate embodiment of the invention.

[0030] Even though some of the embodiments described here include features not found in other embodiments, combinations of features from different embodiments are considered to fall within the scope of the invention and constitute different embodiments, as would be obvious to a person skilled in the art. For example, in the following patent claims, each of the claimed embodiments can be used in any combination.

[0031] Numerous specific details are listed in the present description. However, it should be clear that embodiments of the invention can also be implemented in practice without these specific details. In other cases, generally known practices, structures, and techniques have not been described in detail so as not to impair the understanding of this description. Definitions

[0032] The term "fog" used here refers to liquid droplets suspended in the air. Specifically, fog, as used here, reduces visibility to less than 5 meters, or more precisely, less than 2 meters. Such fog can, for example, be used to conceal valuables from the view of burglars.

[0033] The term “fog-generating fluid” used here refers to any fluid, e.g., a gel or a liquid, or to combinations of fluids, that can be vaporized when passed through a heat exchanger. When the vapor leaves the heat exchanger and enters the range of atmospheric pressure and normal ambient temperature, it condenses into very small liquid droplets that float in the air as an aerosol, forming a visible fog cloud. In the context of the present invention, the fog-generating fluid is preferably a “polyol-containing fog-generating fluid,” meaning that the fog-generating fluid contains a polyol, such as glycol, and optionally water. Even better is the use of a fog-generating fluid containing a polyol and water. It should be noted that, for example,Oil-based smoke generators are unsuitable for indoor use because they are harmful to the health of residents and intruders and leave greasy residue after the suspended particles dissipate. The fog used here (and thus the fog-generating fluid) is therefore not the same as the smoke produced by oil-based smoke generators.

[0034] Nitrous oxide, also known as dinitrogen monoxide, is a chemical compound, a nitrogen oxide, with the formula N₂O.

[0035] The term "propellant" used here refers to a substance, compound, or mixture capable of generating overpressure to force the fog-generating fluid into a fog-generating device, in particular from the container to the heat exchanger of the fog-generating device. Within the scope of the present invention, the propellant comprises nitrous oxide, which can be used alone or in combination with other propellants.

[0036] The terms “push”, “drive” and the like used here are used interchangeably and refer to the flow of the fog-generating fluid, in particular from a container or housing to the heat exchanger of the fog-generating device, under the influence of the overpressure generated by a propellant.

[0037] The term "fog emission" or similar terms used herein generally refer, in a fog-generating device, to the process of driving a fog-generating substance (hereinafter also referred to as fog-generating fluid) through a heat exchanger, whereby the fog-generating substance is converted into the vapor phase, which is emitted at the outlet (the emission nozzle) of the heat exchanger. Fog-generating fluid

[0038] According to a first aspect, the present invention relates to a fog-generating fluid containing dissolved nitrous oxide. As will be clear to practitioners, nitrous oxide can serve as a propellant for the fog-generating fluid, which will be described in more detail below.

[0039] The composition of the fog-generating fluid is selected such that it contains at least one component capable of at least partially dissolving the propellant, in particular nitrous oxide. The fog-generating fluid preferably consists of a polyol, such as a glycol. Suitable (often water-based) polyol-containing fluids are readily available to those skilled in the art. Preferably, the fog-generating fluid contains a polyol, such as glycol, in an amount of 50 to 90% by volume. The inventor has found that nitrous oxide exhibits a surprisingly high solubility in polyols, particularly in diols, especially glycols, thereby providing a large amount of propellant in a small volume of fog-generating fluid. Therefore, in preferred embodiments of the present invention, the fog-generating fluid comprises a glycol (aliphatic diol).The glycol can be selected, in particular, from dipropylene glycol, triethylene glycol, or combinations thereof. Preferably, the glycol contains at least 50% by volume of dipropylene glycol. The presence of dipropylene or triethylene glycol is preferable to lower glycols, such as diethylene glycol, since the former hardly reacts with water at the temperatures prevailing in the device, while the latter is reactive with water and forms corrosive compounds. The presence of dipropylene glycol is preferred because this compound, due to its lower boiling point and lower viscosity, can be more easily converted into an aerosol. The use of a fog-generating fluid containing dipropylene glycol results in a dense, barely transparent fog. In a particularly preferred embodiment, the fog-generating fluid according to the invention therefore comprises dipropylene glycol and optionally triethylene glycol.

[0040] The fog-generating fluid according to the invention preferably consists of water. In other words, the fog-generating fluid can be a water-based fluid. Preferably, the fog-generating fluid contains water in an amount of 5 to 50% by volume. Even more preferably, the fog-generating fluid contains water in an amount of 5 to 15% by volume.

[0041] Suitable fog-generating fluids, particularly water-based ones, are known in the trade. If desired, two or more polyols, particularly glycols, can also be used. In a particular embodiment, the fog-generating fluid contains water in an amount of 5 to 15% by volume. In a particular embodiment, the fog-generating fluid contains glycol, particularly dipropylene glycol and optionally triethylene glycol, in an amount of at least 50%. In a particular embodiment, the fog-generating fluid contains a glycol, wherein the glycol contains 5 to 25% by volume triethylene glycol and 75 to 90% by volume dipropylene glycol. In a particular embodiment, the fog-generating fluid contains dipropylene glycol in an amount of 50 to 90% by volume, preferably 60 to 90% by volume, even more preferably 70 to 90% by volume. In a preferred embodiment, the fog-generating fluid contains dipropylene glycol in an amount of 50 to 90% by volume.-% and water in an amount of 5 to 15 vol%. In a preferred further embodiment, the fog-generating fluid contains dipropylene glycol in an amount of 50 to 90 vol%, triethylene glycol in an amount of 5 to 25 vol%, and water in an amount of 5 to 15 vol%.

[0042] The fog-generating fluid can also contain an alcohol, such as ethanol. Two or more alcohols can be used if desired.

[0043] The fog-generating fluid can also contain additional compounds, if desired. Suitable examples include menthol, tear gas, etc. propellant

[0044] The fog-generating fluid according to the present invention comprises dissolved nitrous oxide. This dissolved nitrous oxide can serve as a propellant for the fog-generating fluid. Dissolving the nitrous oxide in the fog-generating fluid is preferably achieved by compressing the nitrous oxide, e.g., using a pressurized container.

[0045] Nitrous oxide is readily available commercially and can usually be purchased in nitrous oxide tanks and bottles.

[0046] The inventors have discovered that dissolved nitrous oxide as a propellant for the fog-generating fluid offers several surprising advantages. As the example shows, nitrous oxide has remarkably good solubility in the fog-generating fluids according to the invention, particularly in polyols, especially glycols. Furthermore, the addition of dissolved nitrous oxide to the fog-generating fluid slightly increases its volume, especially compared to the prior art. Liquid propellants, on the other hand, such as partially halogenated hydrocarbons, are poorly soluble in fog-generating fluids, generally collect at the bottom of the fluid container, and occupy a considerable additional volume.The use of compressed gas according to the current state of the art also requires a considerable volume in the container, which must be reserved for the propellant, as do designs in which the propellant is separate from the fog-generating fluid. Consequently, the use of nitrous oxide offers a significant volume saving compared to previous propellants, allowing more fog-generating fluid to be provided in a fluid container of the same volume. Another advantage of nitrous oxide is that less energy is required to vaporize the fog-generating fluid containing nitrous oxide, especially compared to fog-generating fluids containing partially halogenated hydrocarbons or other liquefied propellants, while simultaneously generating a sufficiently high gas pressure to expel all of the fog-generating fluid from the fluid container.

[0047] Within the scope of the present invention, nitrous oxide can be used as the sole propellant or in combination with other propellants known in the art. In a particular embodiment, the fog-generating fluid contains dissolved nitrous oxide as the sole propellant. In a certain alternative embodiment, the fog-generating fluid consists of dissolved nitrous oxide in combination with another propellant, in particular a non-toxic, low-flammability, and environmentally friendly propellant. Preferably, each other propellant is selected such that at least a portion of it is soluble in at least one component of the fog-generating fluid and that the total amount of the propellant in the fog-generating fluid is optimized to have a relatively high vapor pressure at room temperature, i.e., a vapor pressure of over 4, preferably 8, and particularly preferably 10 bar.Below 4 bar, the coefficient of expansion of the propellant is low; above 10 bar, optimal atomization is achieved. In a particular embodiment, the fog-generating fluid contains nitrous oxide as the sole propellant.

[0048] In the context of the present invention, the fog-generating fluid typically contains dissolved nitrous oxide in an amount of at least 25 g / l, preferably at least 30 g / l, more preferably at least 35 g / l, and most preferably at least 40 g / l. In particular, the fog-generating fluid typically comprises dissolved nitrous oxide in an amount of at least 25 g / l, preferably at least 30 g / l, more preferably at least 35 g / l, and most preferably at least 40 g / l at a temperature of 20°C. In particular, the fog-generating fluid typically comprises dissolved nitrous oxide in an amount of at least 25 g / l, preferably at least 30 g / l, more preferably at least 35 g / l, and most preferably at least 40 g / l at a pressure of 18 bar and a temperature of 20°C.

[0049] Preferably, the fog-generating fluid according to the present invention is saturated with dissolved nitrous oxide. Furthermore, it is advantageous that the fog-generating fluid according to the present invention is saturated with dissolved nitrous oxide at a pressure of 8 to 30 bar and a temperature of 15°C to 60°C. It is even more advantageous if the fog-generating fluid is saturated with dissolved nitrous oxide at a pressure of 15 to 20 bar and a temperature of 15°C to 25°C. The best result is if the fog-generating fluid is saturated with dissolved nitrous oxide at a pressure of 18 bar and a temperature of 20°C. Housing

[0050] According to a further aspect, the present invention relates to a housing containing the described fog-generating fluid, which can be connected to a heat exchanger of a fog-generating device. The connection between the housing and the heat exchanger can be permanent or detachable. Preferably, the housing is detachably connected to the heat exchanger. In other words, the housing is preferably a detachable housing.

[0051] For illustrative purposes and without limitation, the following are in Fig. Embodiments of standard and optional components of the housing are shown, including a container (001), a connection (004) to the heat exchanger and a valve (003). container

[0052] The fog-generating fluid (006) is typically located together with the propellant (007) in a pressurized container (001) inside the housing. The liquid phases, in particular the fog-generating fluid (006) with the dissolved liquefied propellant (007), are typically located at the bottom of the housing, especially at the bottom of the container (001); the gas phases, in particular the propellant in gas phase, are typically located at the top of the housing, especially at the top of the container (001), which is also referred to here as the headspace (005). Preferably, the housing, in particular the container (001), consists of 85 to 95 vol% of the described fog-generating fluid and 5 to 15 vol% headspace. As described above, the propellant can be nitrous oxide alone or a combination of nitrous oxide with other propellants.

[0053] The housing, in particular the container (001), typically also includes a dip tube (002). The fog-generating fluid (006) can flow from the bottom of the container (001) to the heat exchanger through the dip tube (002) when the valve (003) is open.

[0054] In the context of the present invention, the housing, in particular the container (001), is typically pressurized. Preferably, the pressure in the housing, in particular in the container (001), approaches the vapor pressure of the propellant, in particular the gas pressure of nitrous oxide. Preferably, the fog-generating fluid is located in the housing at a pressure of at least 10 bar. Preferably, the housing has a pressure of 8 to 30 bar at a temperature of 15°C to 60°C, more preferably 15 to 20 bar at a temperature of 15°C to 25°C, and more preferably 18 bar at a temperature of 20°C.It is further preferred that the housing maintains a pressure between 8 bar and 30 bar until 80% or more of the fog-generating fluid, preferably 90% or more of the fog-generating fluid, more preferably 95% or more of the fog-generating fluid, most preferably 99% or more of the fog-generating fluid have been driven from the housing to the heat exchanger at a flow rate between 10 ml / s and 20 ml / s.

[0055] In the context of the present invention, the container (001) preferably has a volume of 0.75 l to 1.5 l.

[0056] The amount of propellant in the housing, particularly in the container (001), can vary within wide limits. Generally, however, care should be taken to ensure that as much propellant as possible is dissolved in the fog-generating fluid, so that the dissolved propellant in the gas phase is in equilibrium with its pressure.

[0057] According to the present invention, the described housing, in particular the container (001), typically contains dissolved nitrous oxide in an amount of at least 25 g / l, preferably at least 30 g / l, more preferably at least 35 g / l, and most preferably at least 40 g / l. In particular, the described housing, in particular the container (001), typically contains dissolved nitrous oxide in an amount of at least 25 g / l, preferably at least 30 g / l, more preferably at least 35 g / l, and more preferably at least 40 g / l at a temperature of 20°C. Connection

[0058] The connection (004) can take various forms depending on the application. For example, the connection can be a tube or a hollow needle, an opening or a slit in a membrane. The connection can, for instance, have a small opening or a tubular section with a small bore, so that the surface tension of the material prevents flow. The connection can be made of flexible or rigid material.

[0059] In the context of the present invention, the connection (004) to the heat exchanger is typically a fluid connection. In particular, the fluid connection enables a fluid-tight connection through which the fog-generating fluid can flow from the housing, especially from the container, to the heat exchanger.

[0060] In the case of a detachable housing, the connection (004) typically includes a coupling (008) to detachably connect the housing to the heat exchanger of the fog-generating device. An example of such a coupling is shown in Fig. of patent WO03001140A1. valve

[0061] In the closed position, the valve (003) prevents the mist-generating fluid from flowing out of the housing. The valve (003) can be located inside the housing, in particular in a wall of the housing or the container. Such a valve is usually directly connected to the container (001). Alternatively, the valve can also be located outside the housing, in particular in the connection (004) between the housing and the heat exchanger.

[0062] The valve (003) can be an on / off valve or a one-way valve. The on / off valve is configured to switch the flow of the fog-generating fluid (006) from the housing, in particular the reservoir (001), to the heat exchanger on and off. Such an on / off valve typically remains closed when the housing is not connected to the heat exchanger or when the housing is connected to the heat exchanger and the fog-generating device is not activated for fog generation. In typical cases, the valve (003) is arranged to open upon activation so that the fog-generating fluid (006) can flow from the housing, in particular the reservoir (001), into the heat exchanger. The on / off valve is typically closed again after being open for a certain period of time to allow fog generation.The standard and optional features of such an on / off valve are described in the patent application, in particular in the claims of patent specification WO03001140A1, which is hereby incorporated into the present disclosure by reference.

[0063] Unlike an on / off valve, a one-way valve does not return to the closed position after opening, thus allowing the entire container (001) to be emptied after a single actuation of the mist-generating device. The standard and optional features of a one-way valve are described in patent EP3017268B1, in particular in the claims of EP3017268B1, which is hereby incorporated into the present disclosure by reference.Accordingly, in a particular embodiment according to EP3017268B1, the valve which, in a closed position, prevents the fog-generating fluid from flowing out of the housing, is characterized in that the valve comprises an elastic energy carrier, a blocking means and a melting wire, wherein the elastic energy carrier exerts a force on the blocking means which is held in a closed position by means of the melting wire; and wherein, after the breakage of the melting wire, the release of the elastic energy from the elastic energy carrier brings the blocking means into the open position.

[0064] In a particular embodiment, the housing of the present invention comprises a valve inside the housing, in particular in a wall of the housing. In an alternative embodiment, the housing of the present invention comprises a valve outside the housing, in particular in the connection between the housing and the heat exchanger. In the latter case, the valve may, for example, be located in or near the coupling for the detachable connection of the housing to the heat exchanger of the fog-generating device. In one embodiment, the housing includes an on / off valve. In an alternative embodiment, the housing includes a one-way valve. In a preferred embodiment, the housing includes a one-way valve in a wall of the housing. An example of the latter type of implementation is shown in Fig. represented by EP3017268B1.

[0065] In a preferred embodiment, the housing is removable, pressurized, and has a connection to a heat exchanger of a fog-generating device. In a further preferred embodiment, the present invention provides a pressurized, removable housing comprising a fog-generating fluid, wherein the fog-generating fluid comprises dipropylene glycol in an amount of 50 to 90 vol.%, water in an amount of 5 to 15 vol.%, and dissolved nitrous oxide in an amount of at least 35 g / l. It is further preferred that the housing includes a valve, in particular a one-way valve, in a wall of the housing. Fog-generating device

[0066] A fog-generating device for security applications is typically based on the principle of glycol vaporization (contained in a fog-generating fluid). The vaporized fog-generating fluid is expelled through an outlet channel and nozzle into the "space to be filled with fog" and immediately condenses under atmospheric pressure and room temperature into a dispersed, aerosol-like fog. This fog obscures the criminal's vision and disorients them. The vaporization process (supply of joules in the form of heat) usually occurs via a heat exchanger. The heat exchanger's inlet is connected to a reservoir for the fog-generating fluid, through which the fluid is injected under pressure into the heat exchanger's inlet at the desired time for fog emission.

[0067] Accordingly, the present invention relates, in one aspect, to a fog-generating device comprising the container or housing as described, which is connected to a heat exchanger, wherein the heat exchanger is configured to generate fog by heating the fog-generating fluid, and includes an outlet opening for expelling the fog under pressure from the fog-generating device. Thus, the gas generated in the heat exchanger is expelled from the fog-generating device into the environment.

[0068] In a preferred embodiment, the fog-generating device comprises a removable housing according to the invention, which can be detachably connected to the heat exchanger of the fog-generating device.

[0069] The connection of the removable housing to the heat exchanger can be made via a coupling, in particular via a coupling in the connecting element between the housing and the heat exchanger. use

[0070] According to a further aspect, the present invention relates to the use of nitrous oxide dissolved in the described fog-generating fluid to drive the fog-generating fluid into a fog-generating device. A particular embodiment of the present invention further relates to the use of nitrous oxide dissolved in the described fog-generating fluid to drive the fog-generating fluid from the described housing to the heat exchanger of the fog-generating device.

[0071] The present invention also relates to a use of the described fog-generating device for generating fog, in particular for generating fog to protect against intruders and / or physical threats from persons. In particular, the invention relates to a use of the described housing for protection against intrusion and / or physical threats from persons. Accordingly, the invention relates to a use of the described fog-generating fluid for protection against intruders and / or physical threats from persons.

[0072] The present invention also provides for the use of a fog-generating fluid, a housing or a fog-generating device as described herein to generate fog. Methods for generating fog

[0073] According to another aspect, the present invention relates to a method for generating fog, wherein the method comprises: (a) Provision of the housing described herein, wherein the housing is connected to a heat exchanger; (b) Use of nitrous oxide dissolved in the fog-generating fluid to drive the fog-generating fluid from the housing into the heat exchanger; and (c) Generation of fog by heating the fog-generating fluid in the heat exchanger.

[0074] In another embodiment, the method comprises a) the provision of an enclosure as described herein, wherein the enclosure is connected to a heat exchanger; b) the use of nitrous oxide dissolved in the fog-generating fluid to drive the fog-generating fluid from the housing into the heat exchanger; c) the generation of gas by heating the fog-generating fluid in the heat exchanger; d) the discharge of the pressurized gas through a heat exchanger from the fog-generating device (to the environment).

[0075] In a preferred embodiment, the housing is a pressurized, removable housing. In a further preferred embodiment, the housing is a pressurized, removable housing containing a fog-generating fluid, wherein the fog-generating fluid comprises dipropylene glycol in an amount of 50 to 90 vol%, optionally water in an amount of 5 to 15 vol%, and dissolved nitrous oxide in an amount of at least 35 g / l. It is further preferred that the housing includes a valve, in particular a one-way valve, in a wall of the housing.

[0076] The fog-generating fluid is converted into its gas phase in the heat exchanger, which condenses upon expulsion through the outlet of the device and forms a darkening fog, for example to conceal valuables and / or confuse an intruder.

[0077] As can be seen from the fog generation method described above, it is not necessary for the removable housing that encloses the fog-generating fluid to be located in the same device that also includes the heat exchanger. EXAMPLES

[0078] The following examples are provided for a better understanding of the present invention. These are intended for illustrative purposes only and are not to be understood as limiting the scope of protection of the present invention. Example

[0079] A housing containing a 1-liter pressure vessel was filled with nitrous oxide (N₂O) at a pressure of 15 bar. Subsequently, 0.9 liters of fog-generating fluid were added to the same vessel by pressurizing it. The fog-generating fluid added to the nitrous oxide gas consisted of more than 90% (w / w) glycol (a mixture of dipropylene glycol and triethylene glycol), supplemented with water. During pressurization, the reservoir was shaken to increase the surface area of ​​the fog-generating fluid for the N₂O gas molecules and thus accelerate the dissolution of the gas in the fog-generating fluid. After pressurization, the pressure in the vessel increased only very slightly to 18 bar, while the volume of the fog-generating fluid remained virtually unchanged. The fog-generating fluid was saturated with 35 g of dissolved N₂O gas at 18 bar.This is demonstrated by the high solubility constant of nitrous oxide in glycol-containing liquids and the negligible effect of the N2O gas on the total volume of these liquids.

[0080] Fig. Figure 1 shows the filled, pressurized 1-liter container (001) containing the fog-generating fluid (006) with dissolved nitrous oxide (007) (together comprising 90% of the container volume) and the headspace (005) containing nitrous oxide in the gas phase (comprising 10% of the container volume). The pressure in the pressurized container was 18 bar at 20°C. The pressure vessel (001) also included a dip tube (002) through which the fog-generating fluid (006), containing dissolved nitrous oxide (007), could flow from the bottom of the container (001) through the valve (003) to the heat exchanger.

[0081] Filling the pressurized container with fog-generating fluid and N₂O gas demonstrated that, at sufficient pressure, the fog-generating fluid could be saturated with dissolved N₂O gas without the dissolved N₂O gas occupying any additional volume within the container. Furthermore, the high solubility of N₂O gas in the fog-generating fluid resulted in a homogeneous solution that could be used entirely for fog production. This allowed the dip tube to be inserted all the way to the bottom of the container.

[0082] To determine the influence of temperature, the container was heated to 50 °C. Despite the increased temperature, the pressure in the container remained below 25 bar. This suggests that the solubility of N₂O gas in the temperature range between 0 °C and 50 °C exhibits an acceptable temperature dependence, providing sufficient safety for the pressure generated by the fog-generating fluid in the container.

[0083] Finally, the driving pressure of the fog-generating fluid was evaluated by connecting the housing to a heat exchanger and opening the valve (003) so that the fog-generating fluid could flow from the container to the heat exchanger at a flow rate of 15 ml / s. The inventors found that all of the fog-generating fluid (0.9 l) was completely forced from the container to the heat exchanger, while the driving pressure in the container remained constant above 10 bar. The fog-generating fluid was then heated to a temperature of 280°C in the heat exchanger, resulting in the formation of a dense, almost opaque fog. Furthermore, the dissolved N₂O gas contained in the fog-generating fluid required only a minimal amount of additional energy from the heat exchanger to heat and vaporize the fog-generating fluid to 280°C. The fluids according to the invention therefore require only minimal thermal ballast to generate fog. Example for comparison

[0084] For comparison, an equivalent test was carried out using a partially halogenated hydrocarbon, namely pentafluoroethane (HFC125), as a propellant.

[0085] A housing, as described in patent WO03001140A1, containing a pressurized container with a volume of 1 l, was filled with 120 g of HFC125 and 0.78 l of fog-generating fluid. The fog-generating fluid was identical to the fluid used in the example above: it contained 10% water and also consisted mainly of dipropylene glycol.

[0086] Fig.Figure 1 shows the filled, pressurized 1-liter container (001) containing the fog-generating fluid (006) and HFC125. Due to the poor solubility of liquid HFC125 in the fog-generating fluid, only a small portion of the HFC125 dissolved in the fog-generating fluid, and the remainder formed a separate liquid layer and sank to the bottom of the container due to its higher density. As in the example above, the liquid phases (006) and (007) together occupied 90% of the container's volume, and the headspace (005), containing HFC125 in the gas phase, occupied 10% of the container's volume. However, unlike the example above, only about 78% of the container's volume was actually occupied by the fog-generating fluid. The pressure in the pressurized container was 15 bar at 20°C.The pressurized container (001) also contained a dip tube (002) through which the fog-generating fluid (006), containing dissolved HFC125 (007), could flow from the bottom of the container (001) through the valve (003) to the heat exchanger. However, in order to limit the flow of the concentrated HFC125, the dip tube (002) had to be positioned further from the bottom of the container, resulting in an additional 10% loss of the fog-generating fluid below it.

[0087] In summary, filling the pressurized container with fog-generating fluid and HFC125 resulted in a total volume loss of approximately 22% of fog-generating fluid compared to the example above.

[0088] Analogous to the example above, the housing was connected to the heat exchanger by opening the valve (003), allowing the fog-generating fluid to flow from the container to the heat exchanger at a flow rate of approximately 15 ml / s, while the drive pressure in the container was also above 10 bar. The inventors found that in this case, most—but not all—of the fog-generating fluid was driven from the container to the heat exchanger, including more than half of the HFC125 present in the container (resulting in approximately 7% of the discharged fog-generating fluid being HFC125). The fog-generating fluid was also heated to 280°C in the heat exchanger, producing a dense, almost opaque fog.However, due to the presence of HFC125 in a separate liquid phase, the heat exchanger had to supply approximately 6% more energy (J / kg) to heat the fog-generating fluid containing HFC125 in liquid phase, probably because HFC125 had to undergo a phase transition from liquid to gas. It can therefore be concluded that the present invention allows for a larger volume of fog-generating fluid in the container, results in a smaller amount of residual fluid in the container at the end of fog generation, and requires less energy for fog generation. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 03001140A1 [0005, 0006, 0060, 0062, 0085] WO 2008132113A1

[0007] EP 2860486A1

[0008] EP 3017268B1 [0063, 0064]

Claims

[1] A fog-generating fluid containing dissolved nitrous oxide in an amount of at least 25 g / l. [2] The fog-generating fluid according to claim 1 further contains a polyol, preferably a glycol, particularly preferably dipropylene glycol and optionally triethylene glycol. [3] The fog-generating fluid according to claim 2, which contains a glycol in an amount of 50 to 90 vol.%. [4] The fog-generating fluid according to any of the preceding claims, containing water in an amount of 5 to 50 vol.%. [5] The fog-generating fluid according to any of the preceding claims, containing dissolved nitrous oxide in an amount of at least 30 g / l, preferably at least 35 g / l, most preferably at least 40 g / l. [6] The fog-generating fluid according to any of the preceding claims, saturated with dissolved nitrous oxide. [7] Housing containing the fog-generating fluid according to one of the preceding claims and which can be connected to a heat exchanger of a fog-generating device. [8] Housing according to claim 7, comprising a valve which, in the closed position, prevents the fog-generating fluid from flowing out of the housing. [9] Housing according to one of claims 7 to 8, wherein the fog-generating fluid is present at a pressure of at least 10 bar. [10] Housing according to one of the preceding claims, wherein the fog-generating fluid comprises dipropylene glycol in an amount of 50 to 90 vol.%, water in an amount of 5 to 15 vol.% and dissolved nitrous oxide in an amount of at least 35 g / l. [11] Fog-generating device with a heat exchanger and the housing according to one of claims 7 to 10, wherein the dissolved nitrous oxide drives the fog-generating fluid from the housing to the heat exchanger. [12] Fog-generating device according to claim 11, which maintains a pressure between 8 bar and 30 bar in the housing until 80% or more of the fog-generating fluid has been driven from the housing to the heat exchanger, wherein the fog-generating fluid is preferably driven from the housing at a flow rate between 10 ml / s and 20 ml / s.

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