Said surface can be a vehicle or pedestrian surface, such as a road, a sidewalk, or others.

Background Art To date, in order to clean roads and sidewalks in urban areas use has been made of water, possibly sprayed in the form of steam on the ground, effectively to remove incrustations, oily substances or other undesired materials, which adhere and are difficult to remove from the surface to be treated.

Thanks to this high-temperature steam, a heating of the treated area is obtained, achieving a certain sterilising effect, which however is not very considerable due to the temperature drop undergone by the steam in contact with the surface to be treated and to the fact that said steam escapes, with a certain rapidity, from the treated surface.

To obtain an effective sterilisation, it would therefore be necessary to maintain the steam jet directed against the surface to be treated for a certain time, with considerable time wastage and the need to employ large quantities of steam. The excessive use of steam, in addition to being in itself too costly due to the heavy use of fuel for vaporisation, requires a continuous supply of water which is not always easily obtainable and constitutes an operative problem of considerable importance.

Disclosure of Invention

A method is provided for sterilising a surface, in particular a surface of an urban or extra-urban area, according to claim 1.

In particular, the method entails causing an exothermal reaction to take place between at least a first and a second substance, and causing said exothermal reaction to develop in substantial contact with the surface to be treated.

In this way, it is possible to sterilise the surface to be treated in an effective manner, without having to employ excessive quantities of steam and to maintain the steam jet in contact with the surface to be sterilised for excessively prolonged times.

Contained treatment costs and a high rapidity of execution of the treatment are thereby obtained.

Also provided is an apparatus that embodies the present method having the characteristics of claim 12.

The secondary claims refer to particular and advantageous embodiments of the invention.

Description of the Drawings Further features and advantages of the invention shall become more readily apparent from the detailed description that follows, made with reference to the accompanying drawings, which represent embodiments provided purely by way of non limiting examples, in which: -Figure 1 shows a lateral schematic view of a first embodiment of a machine that implements the present method; -Figure 2 shows a frontal schematic view of a second embodiment of a machine implementing the present method; -Figure 3 shows a lateral schematic view of a third embodiment of a machine that implements the present method; -Figure 4 shows a lateral schematic view of a fourth embodiment of a machine that implements the present method.

Description of the Illustrative Embodiments In accordance with Figure 1, the apparatus of the first embodiment is in the form of a motorised vehicle 10 movable on wheels 13 and having a support frame 12 for a forward driver's cab 14 and a flatbed 16.

On the flatbed 16 is housed an apparatus 18 for a first and a second substance that are able to react exothermally with each other, in such a way as to produce a high temperature which, according to the present invention, is employed to sterilise the surface whereon they are distributed.

Said apparatus 18, which is contained within a protective shell 19, essentially comprises a container 20 for containing a first substance which can be constituted by quicklime (CaO), soda (NaOH), potash (KOH), orthophosphoric acid (H3PO4), zeolites, preferably in the form of powder, granules or chips, and a tank 22 for containing a second reaction substance, which is preferably constituted by water.

It is possible to use water at ambient temperature. In a preferred manner, however, means for heating said water are provided on the machine, in the form of a boiler 24, whereby it is possible to heat the water to a desired temperature, higher than ambient temperature, which allows to obtain an exothermal reaction with more rapid development reaching a higher sterilisation temperature, or to use a smaller quantity of reactants.

In a further preferred manner, it is also possible to push the heating of the water until bringing it to vaporisation, by way of example it could be possible to obtain a steam having a temperature of 110-120°C at a pressure of 9 atm.

The steam has a temperature that in itself produces a sterilising effect, however if it were placed alone in contact with the ground, it would undergo a rather rapid temperature drop and would not be able to obtain an effective sterilisation.

Instead, the addition of a substance that reacts exothermally with the steam allows to obtain a higher temperature level than that of the steam alone. Moreover, the development of the exothermal reaction also allows to maintain a high level of

temperature for longer time intervals. Hence, the sterilisation obtained is definitely more effective than if steam alone were used.

In the first realisation shown in Figure 1, the ejector 26, fed through a conduit 21 which extends from said container 20, spreads the first reaction substance on the ground, while the sprayers 28, which are fed through the respective conduit 23 starting from the tank 22, spray the steam or heated water on the first substance already spread on the ground. Appropriate pumping means, not shown in the figures, can be provided to move said first and second substance outwards.

The ejector 26 and the sprayers 28 are borne by a common housing plate 27 that can be moved vertically, by means of a hydraulic or pneumatic cylinder 29, between a raised position for vehicle travel and a lowered working position (shown in Figure 1), being able to be set in any convenient intermediate position.

Means, not shown in Figure 1, can be provided for moving said plate 27 which bears the nozzles 26 and 28 transversely to the direction of travel of the vehicle 10.

The number 30, in Figure 1, also indicates a conduit for the ejection of excess steam, and the number 31 indicates instead a conduit for the ejection of the combustion gases produced in the boiler. The outlet openings of said conduits 30,31 can be closed, when the boiler is in non-operating condition, by means of a corresponding door 32.

Figure 2 shows a second preferred embodiment of machine or apparatus that implements the method of the present invention.

This second embodiment is in the form of a vehicle 50 mounting a sterilisation apparatus which substantially presents the same characteristics of the first embodiment and which are not described herein for the sake of descriptive simplicity.

In this second embodiment, said first substance, fed through a respective conduit (not shown in Figure 2), is mixed with the second substance, in turn fed through a respective conduit (not shown in Figure 2), before being expelled outwards through a main conduit obtained within an arm 52.

As the aforementioned figure 2 shows, the arm 52 prolongs transversely from the vehicle and allows to reach points that are removed from the travel way of the movable means 50.

Said arm 52 is in the form of a movable organ, in particular able to collapse and extend telescopically in a transverse direction to the direction of travel of the vehicle, which is appropriately activated to move, under the control of an appropriate electronic unit, in reaction to a signal emitted by a sensor, indicated with the reference S in Figure 2, which is able to feel the presence of an obstacle and which is preferably positioned in correspondence with the extremity 54 for the emission of the sterilising jet 56. Hydraulic or mechanical means of any suitable type could in any case be used to provide such a command.

Figure 3 shows a third preferred embodiment of the apparatus. This third preferred embodiment is in the form of a vehicle 100 which has a sterilisation apparatus 18 substantially similar to that of the first embodiment and which is therefore not commented again. In Figure 3, the elements similar or equivalent to those of the first embodiment maintain the same numerical references as in the corresponding Figure 1.

In this third embodiment, the vehicle 100 has, on the flatbed 16, a compartment 102 wherein are housed the devices for aspirating and storing the material which is drawn from the road through the aspirating brush head 104. The characteristics of said aspirating and storing devices and of any road washing devices which may be provided are traditional and known to the person versed in the art and are not therefore described in detail.

Figure 4 shows a fourth preferred embodiment of the apparatus. Also in Figure 4, the elements similar or equivalent to those of the first embodiment maintain the same numerical reference as in the corresponding Figure 1.

This fourth preferred embodiment is in the form of a means 200 that presents a sterilisation apparatus 18 substantially similar to those of the first embodiment and

which is therefore not commented again herein. Unlike the previous embodiments, the sterilisation apparatus 18 is here borne on a suitable trailer 201 which is towed by a vehicle 203, which presents a compartment 202 wherein are housed the devices for aspirating and storing the material drawn through an appropriate head 204, and any devices for washing the road.

Said aspirating and storing devices and road washing devices are of a wholly traditional type and known to the person versed in the art and it is not therefore necessary to describe them in detail.

Preferably, a substance is used that provides, during the reaction, its own sterilising effect. Specifically, the use of quicklime allows to associate a sterilising effect due to the high temperature caused by the exothermal reaction, which is developed in its contact with the water, with the known caustic properties that this substance has.

It would also be imaginable for the product obtained from the exothermal reaction to be a solid product which presents sterilising properties and which is left on the surface to be treated, guaranteeing such sterilising action over time. In this way it is possible to obtain a sterilising effect also at later times, after the exothermal reaction has ceased to produce its effects.

It should obviously be understood that the present invention is in no way limited to the use of the aforesaid substances in the conditions or states described above. In particular, both the first and the second substance may be in the form of solid, liquid or gaseous materials, of any kind, provided they are able to produce an exothermal reaction.

The invention thus conceived can be subject to numerous modifications and variations, without thereby departing from the scope of the inventive concept. All components can be replaced by technically equivalent elements.