Title

An anti-intrusion system with a fog generator for generating fog at an intrusion event

Technical field

The present disclosure relates to the field security systems which are able to detect intrusion or any other unauthorized presence of a person in a building, room or any other area, and which system comprises a fog generator for generating fog upon detection of the intrusion or unauthorized presence.

Background Conventional anti-intrusion security systems mostly consist at least of one or more (presence) sensors which are able to detect presence and/or movement of persons in a defined surveillance area, as well as an alarm unit which is able to generate an auditory and/or visual alarm signal. The alarm signal is meant to deter the intruder. In practice, however, it appears that often the intruder is not really impressed by the alarm and will only leave the area under surveillance after a certain length of time. During that time, the intruder or thief can cause a lot of damage and/or get what he came for.

The ability of thieves and other intruders to circumvent existing physical security measures, as well as the delay of several minutes before police or private security is able to respond to an alarm prove that these existing security measures to be insufficiently effective.

Fog generators on the other hand are far more effective. Fog generators create dense white smoke which is not only applicable for use in a wide variety of applications such as entertainment applications, training purposes, military applications but nowadays also as an effective anti-intrusion system.

Fog generators emit a dense vapor that has an appearance similar to natural fog, or opaque mist or smoke. The fog generator will almost instantaneously start producing fog and within seconds the room can be filled with a dazzling and dense fog such that unwanted guests are blinded and disoriented. To this end, existing fog generators have a fluid reservoir and an electric pump to pump the fluid to a heat exchanger which evaporates it into particles, creating the desired fog. Such fog generators have the advantage that the fluid is stored in the generator at an atmospheric pressure. This makes re-use by refilling the reservoir easy and relatively cheap. Also, the transport of the fog fluid is easy and does not require specific regulation. These known fog generators however have the disadvantage that it takes a relative long time before the room or area under surveillance is filled with fog sufficient for blinding or disorienting the intruder.

Accordingly, there is a need for an improved fog generator which is able to generate fog more efficiently with a higher volumetric flow rate.

Summary

The above mentioned and other objects are achieved, in a first aspect of the present disclosure, by an anti-intrusion fog generator for generating fog at an intrusion event, said fog generator comprising:

- a fluid reservoir, arranged for containing a volume of fog fluid;

- a heat exchanger, arranged for vaporizing said fog fluid into fog;

- a pump, in fluidal connection with said fluid reservoir and said heat exchanger, arranged for transporting said fog fluid towards said heat exchanger;

- a controller unit, in communicative connection with said pump and said heat exchanger, arranged for driving said pump to transport said fog fluid towards said heat exchanger upon receipt of an anti-intrusion activation signal; said fog generator further comprising:

- at least one fog vessel, in fluidal connection with said heat exchanger, arranged for containing a volume of pressurized fog fluid;

- a valve, located between said at least one fog vessel and said heat exchanger, arranged for allowing transport of said pressurized fog fluid towards said heat exchanger;

wherein said at least one fog vessel comprises a fitting arranged for refill of said at least one fog vessel, and said fog generator is arranged for transporting fog fluid from said fluid reservoir towards said least one fog vessel.

Fog generators are powerful devices that generate a dense white fog by evaporation and condensation of a water-based fog liquid which mostly contains a glycol or glycol based solution with distilled water. The fog fluid is vaporized in a mean droplet size is around 1 pm and the fog's durability can be controlled through the choice of the glycol solution or by additives. The vapour produced is a dense white fog which reduces the visibility to around 30 cm or less.

Known fog generators have a heat exchanger which may comprise a heater and a heater block on or through which the fog fluid is heated and vaporized. The fog fluid of known fog generators is stored in a fluid reservoir in which the fog fluid is maintained at atmospheric or near atmospheric pressure.

To transport the fog fluid from the reservoir to the heat exchanger the fog generator is equipped with a pump. The pump is in fluidal connection with the fluid reservoir and the heat exchanger, e.g. through a circuit of hoses or pipes and is arranged to transport the fog fluid towards the heat exchanger.

The drawback of such fog generators is that the volumetric flow rate is relatively low. Only a limited amount of fog fluid can be pumped to the heat exchanger such that the output of the fog generator in litre of fog per second is that low, that it will take a relatively long time before the room or area under surveillance is filled with sufficient fog that the visibility is reduced significantly and sufficient for a disorientation of the thief or unauthorized person.

To increase the flow rate, fog generators may be equipped with pumps with higher capacity, or by introducing a plurality of pumps. This however will increase complexity of the system as well as the costs. For the system to be able to provide a sufficient volumetric flow rate a high amount of pumps are required. This is off course not preferred.

To increase the flow rate, it is known to use pre-pressurized containers which may be operated through control of a valve. Fog generators with such prepressurized containers are able to generate fog with significantly higher volumetric flow rates. Although such containers are very effective and generate high volumes of fog in a short period of time, they also have several drawbacks.

To the use and transport of pressurized fog containers strict regulations apply, which make use and transport both cumbersome as well as expensive. And since the containers only have a small capacity, such cumbersome and expensive replacement is often required. Moreover, to ensure correct operation of the fog generator, pressurized containers may also have limited shelf life or require regular inspection or replacement. The present disclosure is based on the insight that both slow, atmospheric fog fluid and the fast, pressurized fog fluid can be combined in a single system. The inventor came to the surprising insight that both systems can operate in a hybrid modus in which the advantages of one system eliminate the disadvantages of the other and vice versa. The fog generator according to an aspect of the present disclosure is equipped with a fog vessel that has a fitting for refilling the vessel with fog fluid from the fog fluid reservoir. This way, the fog vessel can be transported in an empty condition such that the strict transport and handling requirements do not apply which makes transport and use far less cumbersome and much cheaper.

The present disclosure is further based on the insight that different requirements apply during different moments of time. Upon detecting the unwanted circumstance, i.e. the alarm event which enables the fog generator to start generating fog, the system should be able to produce fog with a high volumetric flow rate. However, once the room is filled with fog, a lower volumetric flow rate that is significantly lower is sufficient to keep the room filled with fog. As such, the fog generator according to the present disclosure is able to produce fog at different flow rates. One high flow rate for the first time-period which is provided by the pressurised system, and a second low flow rate for the following time-period which is provided by the atmospheric reservoir system. By using the low flow rate system to refill the high flow rate vessel, the fog generator according to the present disclosure obviates the disadvantages of the disposable containers. Expensive and cumbersome replacement of expensive pressurized containers becomes superfluous.

In an embodiment, said at least one fog vessel comprises a first compartment in fluidal connection with said heat exchanger and arranged for containing said pressurized fog fluid, and a second compartment arranged for containing a gas, wherein said first and second compartment are separated by a diaphragm.

Since the fog fluid is preferably a fog liquid, the liquid is difficult to compress. By use of a fog vessel with both a liquid and gas compartments, which compartments are separated from each other by a diaphragm, the gas can be used to keep the liquid under pressure. In other words, the gas compartment enables the liquid to be pressurized.

Known fog generators having pressurized disposable containers have propellant gasses to keep the fog liquid at a predetermined pressure and to drive the fog fluid out of the container. Such propellant gases are for example based on halogenated hydrocarbons which are toxic. This toxic propellant also ends up on the heat exchanger and is thus also vaporized into the room where it may cause damage contamination to people, of premises, stock and personal possessions. As such, the use of this additive is undesirable and may cause an undesirable residue to the room or area under surveillance.

By use of a vessel in which the gas is kept in a separated closed compartment, the vessel is still able to pressurize the fog fluid but prevents propellants or other unwanted additives to end up in the room or area under surveillance.

In an embodiment of the present disclosure, said controller unit comprises a memory unit for storing a pre-determined time-delay value, said controller being arranged to open said valve upon receipt of said anti-intrusion activation signal and to close said valve after expiring of said pre-determined time-delay.

By preventing the pressurized fog fluid to exit the vessel and draining the vessel once the room is sufficiently filled with fog, the controlled may be equipped with a memory to store a pre-determined time-delay. By setting the pre-determined time-delay to correspond to the time needed for the room to be filled with fog, the fog generator will prevent spillage of pressurized fog fluid.

In an embodiment of the present disclosure, said pre-determined time- delay corresponds to a time-delay between activation of said pump and said heat exchanger to vaporizing said fog fluid of said fluid reservoir into fog.

In an embodiment of the present disclosure, said fog generator further comprises a sensor unit for detecting said intrusion event and generating said anti- intrusion activation signal.

The fog generator is triggered and activated upon receipt of an alarm signal. The alarm signal may be generated by an alarm sensor within the generator itself, or from an external stand alone alarm sensor, an alarm sensor from a near or remote alarm system or from a combination thereof. This way the fog generator can be used as a fully operational stand alone system, or integrated into an existing alarm system.

The fog generator may be in operatively connection with one or more additional fog generators for efficient use of existing alarm sensors and greater reliability of the anti-intrusion system. This way use of wiring and superfluous data communication between fog generators and sensors is minimized. This enables the system to activate one or more fog generators based on a trigger in one or another fog generator positioned for example in another location or room. The fog generators can efficiently use mutual information for more accurate detection or verification of intruder events.

In a further embodiment of the present disclosure, sensor unit comprises any one or more of: an acoustic sensor, an imaging sensor, a laser sensor, a radar sensor, an infrared sensor, a radio-frequency sensor.

In yet another embodiment of the present disclosure, the fog generator is triggered and activated upon receipt of an alarm signal induced by the result of an analytical processing, e.g. video processing, face recognition, video based motion detection or space scanning. The analytical processing step can be performed by an algorithm in a local or external controller and can take advantage of artificial intelligence like deep-learning and self-learning algorithms.

In an embodiment of the present disclosure, the fog generator further comprises a pressure sensor, arranged for measuring an actual pressure of said pressurized fog fluid.

With the pressure sensor, the fog generator can determine the pressure in the pipes or hoses that connect the vessel and the fluid reservoir with the heat exchanger. Once the pressure in the vessel drops for example below a certain threshold, the pump can be activated to refill the vessel with fog fluid from the reservoir.

In an embodiment of the present disclosure, the fog generator further comprising a purge valve, and wherein said controller unit is arranged to control said purge valve to purge said pressurized fog fluid upon said actual pressure exceeding a predetermined over-pressure threshold value.

To prevent the fog generator to build up to much pressure, the generator can be equipped with a purge valve which purges a certain volume of fog fluid such that the pressure level drops below the over-pressure threshold value.

In an embodiment of the present disclosure, the fog generator further comprises a further pump, in direct fluidal connection with said fluid reservoir and said heat exchanger, arranged for transporting said fog fluid towards said heat exchanger.

By equipping the fog generator with an additional pump, the generator can refill the vessel and provide the heat exchanger with fog fluid at the same time. This means, that the room can be kept at a certain fog level and that in the meantime the vessel can be refilled for a second security event, e.g. for rapid release of a high volume of fog in a next (adjacent) room.

In an embodiment of the present disclosure, said heat exchanger comprises a temperature sensor, arranged for measuring an actual temperature of said vaporizing of said fog fluid.

To make sure that the capacity of the heat exchanger is used at its optimum, the heat exchanger may be equipped with a temperature sensor. When the temperature drops below a threshold, that could mean that the heat exchanger is malfunctioning, or that a too high volume of fog fluid is pumped to the heat exchanger etc. In such circumstances, the controller may control the valve to smother the valve to achieve a flow rate at which the heat exchanger operates at its optimum.

In an embodiment of the present disclosure, the fog generator further comprises a communication interface for communication of said controller unit with a security system, and wherein said communication interface any one or more of a wireless and a wired communication interface.

The fog generator may communicate with external devices such as an external stand alone security system. This way the fog generator may be incorporated into a fully operational security system.

In an embodiment of the present disclosure, said fog fluid consists of a composition of glycol or glycerine and distilled water.

In a second aspect of the present disclosure a security system is provided for detecting intrusion or unauthorized presence, said system comprising a sensor system for detecting said intrusion or unauthorized presence, as well as at least one anti-intrusion fog generator according to any of the previous claims.

In a third aspect of the present disclosure a fog vessel is provided containing a fitting arranged for refill of said at least one fog vessel and comprising a pressurized fog fluid, said fog vessel being arranged for an anti-intrusion fog generator according to any of the previous descriptions.

Brief description of the drawings

Fig. 1 illustrates, schematically, a traditional fog generator as known from the state of the art. Fig. 2 illustrates, schematically, a first embodiment of a security system with an improved fog generator in accordance with the present disclosure.

Fig. 3 illustrates, schematically, a second embodiment of a security system with an improved fog generator in accordance with the present disclosure.

Detailed description

Figure 1 illustrates, schematically, a traditional fog generator as known from the state of the art.

The traditional fog generator 1 consists of a fluid reservoir 2 an electric pump 3 for moving the fluid to a heater block, which evaporates the fluid into particles, creating the desired fog. The fluid is stored in the reservoir 2 at an atmospheric pressure. The controller unit 5 is arranged for controlling the fog generator 1 , for exampling on an intrusion event.

When an intrusion event occurs, the fog generator 1 is actuated to create a dense white smoke. After a while the room or area under surveillance is filled with fog such that unwanted guests are blinded and disoriented.

Figure 2 illustrates, schematically, a first embodiment of a security system with an improved fog generator in accordance with the present disclosure.

The improved fog generator 20 consists of a fluid reservoir 2, containing fog fluid at atmospheric pressure, a pump 3 for transporting the fog fluid through a circuit of hoses or pipes to the heat exchanger 4 for vaporizing the fluid into fog, a controlling unit 5, a pressure sensor 6, a fog vessel 7 for containing pressurized fog fluid, a valve 8 for allowing transport of the pressurized fog to the heat exchanger 4 and one or more sensors or actuators 9.

The sensors or actuators 9 are in operatively connection with the controller 5 of the fog generator 20, via a hard-wired or a wireless communication interface based on for example Wi-Fi, Zigbee, z-Wave or another wireless data communication protocol and can for example be one or more of a passive infrared, PIR, motion, ultrasonic, microwave or glass break detectors vibration sensor or a magnetic switch. The fog generator 20 can furthermore be triggered and activated upon receipt of an alarm signal remotely induced by for example a remote control centre, whether or not after verification of the trigger event or as a result of an analytical processing, e.g. video processing, face recognition, video based motion detection or space scanning.

Furthermore, a temperature sensor can be present for measuring temperature to make sure the heat exchanger functions correctly. On an intrusion event, one or more of the sensors 9 are triggered and a signal is sent to the controller 5 for actuating the fog generator 20. The intrusion event could be detected by a sensor of the fog generator 20 or could also be supplied by a security system (not shown) which is already present at the location. This way, the fog generator may be used as a security module for the security system. Communication with the security system is arranged through a hard-wired or wireless communication interface, either directly at local level, e.g. via a local Wi-Fi network, or via a wide area network, e.g. in which the fog generator may receive the alarm trigger via an internet connection from a security sensor that is present in the same building and connected to the internet as well.

In the preferred embodiment of the fog generator, the valve 8 opens and the pressurized fog fluid present in the fog vessel 7 is released, generating a dense white smoke very fast and with a high volumetric flow rate. In a short period, the room and area under surveillance is filled with a dense fog. When activating the pump 3, the system generates fog at a lower volumetric flow rate, by transporting the fog fluid from the atmospheric fluid reservoir 2 to the heat exchanger 4, either directly, or via the fog vessel 7. This results in a hybrid system for producing fog at different flow rates.

For example, pump 3 is activated by controller 5 after a certain time interval after opening valve 8, where the time interval can be fixed, variable or zero valued. In another example, pump 3 is activated when pressure sensor 6 detects that the pressure in fog vessel 7 is below a certain threshold value. In yet another example the pump can also be activated by another sensor 9 or an algorithm present in controller 5.

The controller can also be arranged to communicate via one or more actuators 9 to external systems like an alarm panel or lighting devices. In certain circumstances, for example for large rooms or buildings, it is preferred to use more fog generators which can mutually communicate via the one or more sensors or actuators 9 and controller 5.

When the fog generator needs to stop vaporizing fog fluid, for example when the intrusion event has ended, after a certain time-interval or on instruction to stop, valve 8 is closed and pump 3 is stopped by the controller. With valve 8 closed, pump 3 can be used to retill vessel 7 by pressurizing the fog fluid from fluid reservoir 2 into vessel 7. This can be done when the fog generator is in idle mode when no fog needs to be created, but also when the fog generator is in activation mode when creating fog. In the latter case, the valve could be closed when the vessel needs to be refilled to its maximum pressure, for example when pressure sensor 6 detects a pressure in the vessel 7 is below a certain threshold. When the pressure of the fog fluid in vessel 7 is high enough, for example when pressure is above another threshold value, valve 8 is opened and fog generator 20 continues with generating fog at a high volumetric flow rate.

Figure 3 illustrates, schematically, a second embodiment of a security system with an improved fog generator in accordance with the present disclosure.

The fog generator 30 consists of an additional pump 3A in direct fluidal connection with the fluid reservoir 2 and heat exchanger 4 for directly vaporizing the fluid into fog.

With the additional pump 3A, fog generator 30 can refill vessel 7 and at the same time provide heat exchanger 4 with flog fluid. For quick response on an intrusion event, valve 8 is opened for generating fog at a high volumetric flow rate. After a certain time interval of after input of one or more sensors 9, valve 8 can be closed and pump 3B is activated for refilling vessel 7 for a future security event while pump 3A continues generating fog at a lower volumetric flow rate into the room.

Other variations to the disclosed examples can be understood and effected by those skilled in the art in practicing the claimed disclosure, from a study of the drawings, the disclosure and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps and the indefinite article“a” or “an” does not exclude a plurality. A single processor or other unit may fulfil the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A computer program may be stored/distributed on a suitable medium, such as optical storage medium or a solid- state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not construed as limiting scope thereof. Similar reference signs denote similar or equivalent functionality. The present disclosure is not limited to the examples as disclosed above, and can be modified and enhanced by those skilled in the art beyond the scope of the present disclosure as disclosed in the appended claims without having to apply inventive skills and for use in any data communication, data exchange and data processing environment, for example for use of the fog generator is an a professional entertainment application as theatrical smoke and fog generator.