The present invention relates to a safety fog generator device.

More in particular, the present invention relates to a fog generator device with an anti-theft function suitable for installation and use in civil, commercial and/or industrial environments.

As is known, fog generator devices are anti-theft devices whose function is to generate a very dense fog curtain such as to prevent the vision of malicious persons attempting a robbery or break-in.

The fog generator device is a type of anti-theft device defined as "proactive" which, unlike what occurs with anti-theft devices of the sound type, does not activate against the attacker by emitting a sound signal, but acts by generating a real blanket of smoke or intense, dense fog such as to completely remove the visibility of the attacker who thereby fails to complete the planned action of theft or robbery or the like. The fog emitted by the fog generator devices consists of a fog generator fluid which is evaporated very quickly and then condensed into micro droplets with dimensional features which prevent light from passing through them, causing a diffusion phenomenon which prevents the visibility of the attacker or thief.

The generation of smoke or fog occurs by means of a boiler which, when the alarm signal is activated (following the detection of an intrusion or an attempt to break in), emits a jet of pressurised smoke which propagates very quickly and uniformly within the room and which remains for a few minutes in such a room, preventing, as described above, visibility and thus deterring the thief or malicious person from his criminal act. Typically, if necessary, a suitable fluid is injected into the boiler and the transformation into smoke or fog (transition from the liquid to the gaseous state) occurs due to the high temperatures reached inside the aforementioned boiler.

The fog generator device is sized as a function of the features of the room or rooms to be protected and can be installed on a wall, on a ceiling of the room or can be stabilised on a piece of furniture or similar furnishing accessories; alternatively, such a device can also be "hidden" inside a piece of furniture (for example, a cabinet or a drawer) so as not to be visible from the outside.

Typically, the fog generator devices comprise a body-container in which are housed a tank for the liquid, a liquid introduction system, a heat exchanger to define an accumulation of thermal energy necessary to allow heating the liquid and an evaporation thereof and a nozzle for the introduction of the pressurised, high- temperature liquid processed by the heat exchanger. The liquid introduction system can be of the pressure type or pump type and has the function of giving the fluid introduced in the exchanger a pressure and a speed sufficient to ensure an adequate emission of vapour to the outside (for the creation of fog); the speed of the fluid is an important parameter for the fog generator devices, given that the higher the fluid emission speed the higher the vapour emission speed and, consequently, the better the quality of the fog.

The pressurised introduction system uses pressure tanks and valves which process the pressurised fluid and introduce it into the heat exchanger; such a solution allows for high fluid introduction rates in the heat exchanger.

The pump introduction system makes use of mechanical or diaphragm type pumps which withdraw fluid from the tank and introduce it pressurised in the heat exchanger.

However, the pressurised-type introduction systems have drawbacks related to the dangerousness of the pressurised tank, the problems related to storage as well as those related to the transport and refilling of such tanks, operations which tend to be complex, long and expensive.

The pump introduction systems have a drawback related to the fact that they cannot make use of expanding products adapted to improve the heat exchange inside the heat exchanger and tend to have high consumption, having to use fluid mixtures substantially free of impurities. This drawback is partially solved by the use of continuous-flow mechanical volumetric pumps which allow a denser and less water-rich fog generator fluid to be used.

A known solution is described in W02020/060395 which discloses a safety fog generator device comprising a fluid tank, a heat exchanger, a pump, in fluid connection with the fluid tank and the heat exchanger, a control unit in connection with the pump and the heat exchanger and operable to drive the pump upon receipt of an anti-intrusion activation signal and with the fog generator device comprising a fog vessel in connection with the heat exchanger and adapted to contain a volume of pressurised fog fluid, a valve to allow the transport of the pressurised fog generator fluid to the heat exchanger.

Another known solution is described in US2015/321970 and refers to a fog generator device comprising a reagent, ignition means, a tank containing a fog generator material and a heat exchanger in which the gas generated by the ignition of the reagent guides the fog generator material from said tank to said heat exchanger and in which a removable housing is included for the fog generator device comprising a reagent and a tank provided with fog generator material functional to allow easy maintenance. Another document US2010/0142933 discloses a fog generator comprising a vessel containing a fog generator fluid, actuating means for conveying the fluid from the vessel to a heat exchanger which transforms the fog generator fluid into vapour and is connected to the vessel, a means for expelling the vapour in the form of fog and connected to the heat exchanger, a valve for switching the flow of the fluid from the vessel to the heat exchanger and a means for purging the non-expelled vapour from the heat exchanger into the environment connected to the fluid drive means. However, the traditional devices described also have drawbacks related to the efficiency of the heat exchanger which, not being optimal, affects the overall efficiency of the fog generator device itself. A further drawback of the traditional devices is related to clogging problems of the hydraulic circuits caused by the drying of the remaining fluid in the circuit after dispensing.

The object of the present invention is to overcome the drawbacks described above. More in particular, the object of the present invention is to provide a safety fog generator device which allows an increase and optimisation of the yield and overall efficiency of the device.

A further object of the present invention is that of providing a fog generator device which prevents the hydraulic circuit clogging problems.

A further object of the present invention is to provide a fog generator device which ensures an optimal efficiency of the heat exchanger suitable to compensate for the limitations of the pump introduction systems which cannot use expanding products. A further object of the present invention is to provide users with a safety fog generator device adapted to ensure high resistance and reliability over time and furthermore, such as to be easily and economically made.

These and other objects are achieved by the invention having the features according to claim 1 .

According to the invention, a safety fog generator device is provided with anti-theft function in civil, commercial and/or industrial environments, comprising a body- container inside which are housed the components suitable for the operation of the device and comprising a tank inside which a fog generator fluid to be vaporised is stored, at least one heat exchanger for thermal energy release to the fog generator fluid coming from the tank in order to produce the vapour externally expelled through an outlet duct provided with a nozzle, processing means for the fog generator fluid coming from the tank, comprising at least one mechanical pump, a valve group, a filtering group of the air outside the body-container, at least one detection means and a control unit.

Advantageous embodiments of the invention appear from the dependent claims. The constructive and functional features of the safety fog generator device of the present invention can be better understood from the following detailed description, in which reference is made to the attached drawings which illustrate a preferred and non-limiting embodiment thereof, in which: figure 1 depicts the safety fog generator device of the invention according to a diagram of the constituent elements.

With reference to the aforementioned figure, the safety fog generator device of the invention, indicated overall with 10 in the aforementioned figure, comprises a body- container 12 inside which are housed the components suitable for the operation of the device which define a circuit comprising a tank 14 inside which a fog generator fluid to be vaporised is stored (for example, glycol or a mixture containing glycol or a glycol-based fluid and, in any case, a fluid or a non-toxic mixture), at least one heat exchanger 16 suitable for releasing energy to the fog generator fluid coming from the tank 14 in order to produce the vapour expelled externally through an outlet duct 17 provided with a nozzle 19, means for processing the fog generator fluid coming from the tank defined by at least one pump 18, a valve group 20, a filtering group 22, at least one detection means 24 and a control unit 26.

The at least one pump 18, of mechanical type (not described in detail as known), is arranged between the tank 14 and the heat exchanger 16 and has the function of withdrawing the fog generator fluid from the tank 14 and introducing it pressurised in the heat exchanger 16; in addition to the introduction function, the same pump 18 has the ventilation function of the circuit and the exchanger.

The valve group 20 (which comprises an "on-off" type solenoid valve group and a flow exchanger which allows air or fog generator fluid to flow alternately to the pump) is arranged between the tank 14 and the at least one pump 18 and is connected to the filtering group 22 (defined by a dust filter) arranged upstream of the valve group; such a valve group has the function of withdrawing air from the environment (air which is filtered by means of the filtering group 22) and introducing it into the circuit and into the heat exchanger in order to eliminate fluid residues present in the circuit and in the heat exchanger (in fact, the stagnation of fluid residues in the hydraulic circuit and in the exchanger for prolonged periods of time can cause damage to the circuit itself and, therefore, compromise the proper operation of the fog generator device). The heat exchanger 16 (one or more heat exchangers) referred to in the embodiment of the device of the invention is a heat exchanger with balls which comprises an internally hollow container element filled with balls, preferably steel; the balls define a heat exchange surface with which the operating fluid comes into contact and, depending on the spherical shape, define a contact surface greater than that which characterises tubes or plates or fins or other known structures used in traditional heat exchangers and the use of the balls allows a change in the temperature of the fog generator fluid (an increase in temperature by means of the heat exchanger 16 the fluid passes from room temperature to a temperature of about 160°C) to the desired values more quickly than those of traditional type heat exchangers.

The balls of said heat exchanger 16 can all be of the same diameter or can be characterised by different diameters and are arranged within the hollow container element of said heat exchanger to define zones in succession corresponding to different phases of variations in the state of the operating fluid introduced into the heat exchanger.

Experimental tests showed a fog dispensing in a time interval of approximately 14 seconds, lower with respect to the 25 seconds of equivalent heat exchangers or boilers of known type. As described above, the heat exchanger 16 expels the vaporised fog generator fluid through the duct 17 and the nozzle 19, the latter with the function of nebulising the high-temperature fog generator fluid (in fact, the fog is generated by contact of the high-temperature fog generator fluid nebulised with the external air).

Said nozzle 19 is defined, in accordance with the preferred embodiment, by one or more holes (not shown in figure 1 ) from which the fog generator fluid exits and by air conveyors which increase the contact with the external air generating a thicker and denser fog.

Such a constructive configuration allows an increase in efficiency which is 40% greater than a similar fluid consumption processed by a boiler with a nozzle of known type).

The fog generator device of the invention comprises, as described above, at least one detection means 24 comprising an infrared or laser type presence sensor or a volumetric sensor or a camera which detects the presence of a possible malicious person or thief and activates the operation of the fog generator device. The detection means is applied to the body-container 12 or, alternatively, can also be remotely arranged in defined points of the room in which the fog generator device is applied. Moreover, the detection means can be multiple and of different types (infrared, laser, etc.) and all configured to interact with the fog generator device.

The control unit 26 is connected to the detection means 24 and the components housed in the body-container 12 and has the function of regulating the operation of the latter following the signals coming from the detection means 24.

The control unit 26 can be connected to the home automation system of the commercial/industrial/civil space and, by means of special software, allows remote control and monitoring of the fog generator device, for example, with a smartphone by means of a dedicated application.

The fog generator device of the invention is also autonomous and self-installing since it is provided with a standard power cable and plug and remote controls; it can thereby be implemented by the end user without the intervention of a specialised technician.

As can be seen from the above, the advantages obtained by the safety fog generator device of the invention are clear.

The safety fog generator device of the present invention advantageously allows to overcome the low efficiency problems of the heat exchanger; in fact, the device of the invention, by virtue of the presence of the ball exchanger, allows to achieve a 50% increase in efficiency.

Tests carried out considering an exchanger with a mass of 6 kg adapted to deliver 200 m ² of fog generator have shown that the heat exchanger referred to in the device of the invention dispenses such an amount of fog in 14 seconds consuming 130 g of fluid, while a traditional exchanger with the same features dispenses 200 m ² of fog generator in 25 seconds with a consumption of 180 g of fluid.

A further advantage of the fog generator device of the invention is that it allows to avoid the problems of clogging the circuit by virtue of the presence of the valve group arranged between the tank and the at least one pump connected to the heat exchanger and to the filtering group which filters the air withdrawn from the external environment.

Furthermore, it is advantageous that the fog generator device of the invention, considering the combination of constituent elements composing it and which interact with each other, allows an improvement of the nebulisation yield (in terms of density and persistence) of 40% with respect to the traditional devices.

Although the invention has been described above with particular reference to an embodiment given merely by way of non-limiting example, numerous modifications and variations will be apparent to a person skilled in the art in the light of the above description. Therefore, the present invention intends to embrace all the modifications and variations which fall within the scope of the following claims.