DESCRIPTION

The present invention relates to a generator of gas from a liquid solution, in particular a sterilizing solution .

More precisely, the present innovation relates to a generator of steam gas from a liquid solution, in particular of hydrogen peroxide, which comprises:

• the use of a micronizer, connected to

• an introduction device;

• the use of compressed or ventilated or pumped air inside the introduction device, where the micronized solution creates gas by diffusion and heating.

Such a generator is adjustable, compact and efficient and minimizes maintenance interventions due to residues and encrustations deriving from the evaporation process of the water and hydrogen peroxide solution.

Prior art

How to produce steam (gas not in saturation) from a liquid solution is known: the solution is introduced onto a heated plate, by means of a special pump.

Applied to hydrogen peroxide, such a technique has the disadvantage of leaving a solid residue on the plate, as hydrogen peroxide is never pure, containing preservatives (stabilizers).

Furthermore, the use of the plate increases the necessary dimensions of the steam production device, and the dimensions of the fan for steam distribution.

In turn, the use of fans implies the use of special filters, because the fan circulates impure ambient air.

Also known are devices such as the one described in US 2013/0084215 Al in which the steam (for example of hydrogen peroxide) itself is produced by ultrasound and is transported with a carrier gas, for example ambient air. However, such a device heats the hydrogen peroxideair mixture after the mixing thereof, making it pass through a chamber with a heating resistor (regardless of whether air is fed into the evaporator already preheated). Such a procedure is harmful in that the hydrogen peroxide is heated directly in contact with the resistor and the peroxide molecule is dissociated, losing a certain amount of sterilant, while increasing the humidity (due to the greater presence of H2O) and therefore increasing the saturation of the volume. Furthermore, the hydrogen peroxide is diluted in water with a stabilizer, which when the water is removed, settles on the heating element or walls creating an undesirable encrustation situation. Furthermore, the device described must be inserted in a complete circuit, as it is missing the various control units, replaceable solution containers, pumps, etc., and therefore it is not compact and transportable.

US 2011/058986 Al has a similar system to that of US 2013/0084215 A1, i.e., the carrier gas-steam mixture is heated after mixing.

Patent document US 2019/314535 Al describes an evaporator in the context of a sterilization chamber. The sterilizing agent is evaporated and then mixed with a plasma, subsequently heated before entering the sterilization chamber (Fig. 1A, the means 26 are downstream of the evaporator). The figures related to the evaporator itself (Figures 1B-1D) do not show heating means. Heat may not be necessary (par. 231) although it may be present in an unspecified form. Furthermore, the evaporator requires means for removing moisture ("wicking material") which are not always desired and make the evaporator more expensive and less compact.

There remains the need for a generator of gas (which can be called "steam gas") from a liquid solution, in particular hydrogen peroxide, which is adjustable, compact (containing all the necessary components without external functional elements) and does not give rise to sanitizing solution loss phenomena due to molecular dissociation, internal encrustations due to the sanitizing solution, high heating temperature, which would compromise the use thereof after a relatively short use and/or would provide low operating efficiencies.

There is also the need for a steam gas generator which can be used in retrofit on existing machines which need sterilizat ion/sanitization (or other) or for sanitizing environments.

Purpose and object of the invention

It is the object of the present invention to provide a generator of steam gas from a liquid solution, in particular a sterilizing solution of H ₂ O ₂ , which solves the problems and overcomes the disadvantages of the prior art.

The present invention relates to a generator of steam gas from a liquid solution according to the appended claims.

Detailed description of embodiments of the invention

List of drawings

The innovation will now be described by way of nonlimiting example, with particular reference to the figures of the accompanying drawings, in which:

— Fig. 1 shows a vertical section of the device according to an embodiment of the innovation;

— Fig. 2 shows the lower base of the device according to an embodiment of the innovation;

— Fig. 3 shows the casing of the device according to an embodiment of the innovation;

— Fig. 4 shows the air pressurization assembly according to an embodiment of the innovation;

— Fig. 5 shows the air diverter according to an embodiment of the innovation;

— Fig. 6 shows the assembly for nebulizing the solution and heating the air according to an embodiment of the innovation, in a side view (a) and in a perspective view from below (b);

— Fig. 7 shows the container of the sanitizing solution in the connection thereof to the neck on the outlet of the device, according to an embodiment of the innovation; — Fig. 8 shows the air filter according to an embodiment of the innovation;

— Fig. 9 shows an electronic board of the device according to an embodiment of the innovation;

— Fig. 10 shows a piezoelectric micronizer according to an embodiment of the innovation;

— Fig. 11 shows a further control component of the device, according to an embodiment of the innovation; and

— Fig. 12 shows an assembly with the filter support, the radial/tangent ial fan and the compressor support, according to an embodiment of the innovation; and

— Fig. 13 shows a vertical section of the device according to an embodiment of the innovation.

It is worth noting that hereinafter elements of different embodiments may be combined together to provide further embodiments without restrictions respecting the technical concept of the innovation, as those skilled in the art will effortlessly understand from the description.

The present description also refers to the prior art for the implementation thereof, with regard to the detail features which are not described, such as elements of minor importance usually used in the prior art in solutions of the same type.

When an element is introduced, it is always understood that there may be "at least one" or "one or more ". When a list of elements or features is given in this description, it is understood that the finding according to the innovation "comprises" or alternatively "consists of" such elements.

The various components mentioned below may conveniently be made in one piece in groups of two or more where feasible.

"Cylindrical crown" (or "cylindrical ring") hereinafter substantially means a volume comprised between two coaxial cylinders of equal height and different radius.

Embodiments

Referring to Figure 1, the device 100 is shown composed as a cylinder, therefore extending along a vertical axis z, which can have, in use, at least one non-zero component opposite to the direction of gravity.

Starting from below, there is a bottom 70 to which an electric power socket and switch assembly 71 is connected, which can be operated from outside the cylinder, or from outside the casing 10, which is also shown in Figure 3.

The bottom 70 is better shown in Figure 2 with the external switch 72 and power socket 73.

Externally in the lower part of the cylinder there is an air filter 90, for example cylindrical, dashed in figure 1 and adjacent to the inlet 11 of the casing 10. The filter 90 can be inside low slots 11, as also shown in Figure 3. Such a filter 90 (filtering media) of the air A is also shown in Figure 8, can also be of pharmaceutical grade, by means of which the dew point of the air is lower than or equal to -40 °C.

Inside the filter there can be a compartment for housing one or more electronic boards 80 for controlling the device, in particular the board 81 for controlling a piezoelectric (Figure 9) and the board 82 for power control (Figure 11). The air filter is preferably non- rigid, and is supported by the cylindrical structure 75.

Immediately above the lower section just described, substantially identified by the vertical dimension of the filter 90 or of the support structure 75, there is a fan 65 which sucks air from below and directs it radially, possibly with a tangential component so as to trigger a rotation of the air even until it comes out from the device. An air conveyor 60 is placed coaxially to the fan 65, which air conveyor 60 redirects the air towards a cylindrical crown inside the casing 10 close to the inner walls. Such a cylindrical crown is substantially empty to allow the air to flow, i.e., it does not contain materials through which the air must pass in order to be able to mix with the aerosol droplets nor to carry out any heat exchange.

Figure 12 shows a detail of the ventilation structure or assembly, in which the fan motor 68 is visible. The fact of redirecting the air A in a thickness from the inner walls of the casing is necessary because this air will have to be heated and then join with the generated aerosol, as will be seen later.

A compressor 50 (compression assembly) is placed on the plate 67 above the fan, which compressor 50 contributes to the nebulization (or atomization) through a nebulizer 55 for example in the form of a piezoelectric, shown in greater detail in Figure 10, with the vibrating plate 56.

The air AD deflected (or "diffused", however not preheated) by the conveyor 60 is directed towards one or more resistors 40 (heating assembly or unit), in particular at least two annular resistors 41, 42 and is therefore heated (conveniently at temperatures of about 60-80°C, in particular 65-75°C) forming heated air AR before continuing upwards, meeting the aerosol V created by the piezoelectric 55 and emerging from the holes 31 (one or more radial outlet elements, in general air outlet means in a direction which has at least one radial component, i.e., perpendicular to z) of the internal cylinder 30, thus forming a steam gas G which is pushed upwards at the same time (suitable passages 17 are present (outlet of the steam gas G) in the upper base 15 of the device cylinder, not shown) outside the device 100.

The resistors 40 radially cross said cylindrical crown at least in part. In place of the resistors, there may be other heating means, for example gas heating means. The positioning of the heating assembly 40 in the circular crown is functional to a greater compactness of the device, in addition to the fact that the air is heated just before coming into contact with the nebulized solution, i.e., before creating a mixture which immediately afterwards exits the device without much impact on the inner walls. The outlet 17 can also be separated from the base 15, for example on the adjacent side wall, in any case it will be closer to the base 15 with respect to the holes 31.

The compressor is best shown in Figure 4, showing the diaphragm pump 51 and the electric motor 52.

The aerosol is formed inside the nebulizer cylinder 30, better detailed in Figure 6. This cylinder is closed on the lower base by a plate 33 where the housing 56 of the piezoelectric is also placed. The plate 33 is crossed by a duct 51 coming from the compressor 50. The compressed air AC (dashed arrow) enters the passage duct 51 and then continues into an extension duct 53 (inside the cylinder 30 and not interfering with the pipe 32 of Figures 1 and 7) for example up to approximately the height of the holes 31. The compressed air AC puts the nebulization or atomization cylinder 30 under pressure in the upper part thereof (see the curved arrows, the upper base of the nebulization cylinder being closed as well) and therefore releases the aerosol V created by the piezoelectric. The resistors 40, as described above, are placed outside the vaporization cylinder, but before the holes 31.

Simultaneously with the action of the compressed air, the piezoelectric 55 produces aerosol, starting from the solution 21 present in the replaceable cartridge or container 20. The cartridge is fluidly and mechanically connected to the outlet with the top of the cylinder 10+15, in particular with a neck 16 emerging from the base 15, for example through a snap-fit connection. The sanitizing solution (or any other liquid which can be nebulized with the device 100), for example H ₂ O ₂ , falls by gravity into the nebulization assembly (or "means") 30, 55 through a pipe 32. The positioning of the container 20 is such that it can be easily replaced when the sanitizing solution is finished, and makes the entire device compact, together with the positions of the other elements.

According to a variant of the innovation, the pipe 32 does not reach the base 33 from the inside of the cylinder 30. The pipe 32 (see Figure 7) reaches a certain level (distance d) from the bottom which will be the liquid level with respect to the base 33 in the direction of the axisz, beyond which there will be no introduction of air into the container 20 and therefore the liquid will no longer be able to fall.

The liquid on the base or bottom 33 will be progressively nebulized on the plate 56 of the piezoelectric 55 (see Figure 10) and will rise in the form of droplets inside the cylinder 33 until it meets the compressed air AC with which it will mix and exit from the holes 31.

The nebulizer 55 is a piezoelectric ultrasound generator which lowers the surface tension of the sanitizing solution.

This arrangement allows maintaining the aerosol flow in the center of the tube 30, and therefore avoiding the deposit of aerosol on the walls of the pipe which would cause encrustation phenomena. Figure 7 also illustrates an embodiment of the upper base 15, where the slots for the exit of the steam gas produced by the device 100 can be seen.

In the device of the invention, according to a further embodiment, adjustment means of the temperature of the output steam gas flow (not shown), such as appropriate heat exchangers, can be provided. In particular, there may be means for detecting the temperature of said heated air AR, coupled in feedback with the heating assembly 40.

According to a different embodiment, also with reference to Figure 13, a generator 100' of steam gas G is included, in which the nebulization assembly 30 is provided with aerosol ventilation means configured to release the aerosol V from said aerosol outlet means 31, hereinafter detailed only in some sub-variants.

Said aerosol ventilation means comprise at least one duct 35 configured to introduce ventilated air from outside said nebulization cylinder 30. The duct 35 can be placed above said aerosol outlet means 31 and is configured to introduce air into the cylinder 30 in order to facilitate the exit of the micronized product towards the opening 31. The air which is introduced can be taken in many different ways, as part of the compressed air of the compressor assembly for closing the bottom of the cylinder 30 or created by further air flow production means. In the figure the duct is shown open towards the cylindrical crown but in reality it is connected to an air flow source.

An opening is provided on the bottom 33 of the cylinder 30 which can be closed by corresponding means 95 for closing said bottom. Said means for closing said bottom can be configured to simultaneously close a circular opening 36 of said nebulization cylinder 30 forming at least in part said aerosol outlet means 31.

The closing means of said bottom 33 can be actuated by means of springs and compressed air. In this case, means for generating 56 compressed air AC can be provided, placed at a fan assembly 60,65,68.

There can also be two tubes 32, one for the air and one for the sanitizing solution.

A different compressed air generator 50 can be placed between the fan assembly 60,65,68 and a nebulization assembly 30 is inserted, as in the previous variant (Figure 1).

In all the embodiments, a hydrogen peroxide sensor (not shown) configured to measure the hydrogen peroxide level in said inlet air A or in the environment to be sanitized can be further provided or connected to the steam gas generator, in order to adjust the operation of the sanitizing device, by means of the above electronic boards.

Advantages

The particular dynamic pressurization/ventilation system in the device according to the invention ensures the emission only of sufficiently small, nebulized, heated droplets to be vaporized at a low temperature, i.e., preferably between 60 and 80 °C, even more preferably between 65 and 75° (temperature of the steam gas G in the figures). Such an effect is obtained by rotating the air mass inside the aerosol generator both horizontally and vertically, as shown above (arrows in the figures).

The generator of aerosol from a liquid solution, in particular hydrogen peroxide, according to the innovation, is adjustable and compact.

There is no production of condensation and impurities as in the generators of the prior art. Moreover, by virtue of the fact that the carrier gas is heated before it meets the aerosol, the latter can evaporate at a temperature even below 70°C, and therefore with a certain energy saving.

It can be used in retrofit on existing sterilization (or other) machines, as it extends along a tube which can be adapted in shape and length. It does not necessarily have to be straight.

The generator according to the innovation and the circuit in which it is inserted can be used in all those fields where aerosol is necessary, for example, but not exclusively, in the pharmaceutical field or in the sanitization of operating rooms or clinics, in general in any closed environment.

The preferred embodiments of the present innovation have been outlined above, but it is to be understood that those skilled in the art may make modifications and changes without thereby departing from the scope of protection thereof, as defined in the appended claims.