Generator of vapor gas or aerosol from a liquid solution, in particular a sterilizing solution

Abstract

The present innovation relates to a device (1000) for generating vapor gas (G) or aerosol (AE) from a liquid solution (L) and air (A), comprising a forced ventilation unit (100) fluidly connected to a heating unit (200) for air (A) which enters laterally into a tube (300) fluidly connected to a cylinder (400), the tube and the cylinder being coaxial along an axis (z) oriented, in use, along the direction of gravity, wherein in the cylinder (400) there are provided from the bottom upwards: an aerosol generation unit (470) with a vibrating surface (475) facing upwards, configured to produce a vapor gas (G) or aerosol (AE); an expansion chamber (460) of the liquid solution (L) with a flared development upwards from the vibrating surface (475) up to a free surface (SL) of the liquid solution; a formation chamber (410) for the vapor gas (G) or aerosol (AE) above said free surface (SL). The generator according to the invention allows the air to descend into an annular gap (360) of the tube in a swirling manner and the vapor gas to rise vertically in a central channel (320) of the tube at a low temperature, below 40°C.

Description

[0001] Generator of vapor gas or aerosol from a liquid solution, in particular a sterilizing solution

[0002] To: OC s.r.l.

[0003] Inventor: Gerardo Ceccacci

[0004] The present invention relates to a generator of vapor gas or aerosol from a liquid solution, in particular a sterilizing solution.

[0005] Background art

[0006] How to produce vapor (non-saturated gas) from a liquid solution is known: a heated plate is used, on which the solution is introduced by means of an appropriate pump.

[0007] Such a technique, applied to hydrogen peroxide, has the disadvantage of leaving a solid residue on the plate, because hydrogen peroxide is never pure, containing preservatives (stabilizers).

[0008] Devices such as that described in US 2013 / 0084215 Al are also known, in which the vapor (e.g., of hydrogen peroxide) is produced per se by ultrasound and is transported with a carrier gas, e.g., ambient air. However, such a device heats the hydrogen peroxide-air mixture after the mixing thereof, allowing it to pass through a chamber with a heating resistance (regardless of whether air is fed into the evaporator after being preheated) . Such a procedure is harmful since hydrogen peroxide is heated directly in contact with the resistance and the peroxide molecule is dissociated, losing a certain amount of sterilant, while increasing the humidity (due to the greater presence of H20) and therefore increasing the saturation of the volume. Furthermore, hydrogen peroxide is diluted in water with a stabilizer, which settles on the heating element or walls creating an undesirable encrustation situation when water is removed.

[0009] Patent document US 2011 / 058986 Al discloses a system similar to that of US 2013 / 0084215 Al, i.e., the carrier gas-vapor mixture is heated after mixing.

[0010] 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, then heated before entering the sterilization chamber (Fig. 1A, the means 26 are downstream of the evaporator) . The figures related to the evaporator itself (Figs. 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.

[0011] Document WO2022069975A1 describes a generator of vapor gas from a liquid solution and air, comprising a cylinder with a first base and a second base aligned along an axis having a component opposite to the direction of gravity, the cylinder having opposed air inlet and outlet, a neck at said outlet which is mechanically and fluidly connectable to a container of the liquid solution, as well as the following units arranged in line from the first base to the second base along the axis:

[0012] - a fan assembly for creating a flow of diffused air along a cylindrical crown coaxially to said axis;

[0013] — a nebulization assembly for the liquid solution from said neck, positioned inside said cylindrical crown and adapted to radially emit aerosol; where there is a heating unit for the diffused air, configured to create heated air from said diffused air, the heated air mixing with said aerosol and creating said vapor gas before said outlet.

[0014] Such a solution is not applicable to sterilizations in the pharmaceutical industry where a logarithmic reduction of the bacterial load greater than 10-6is necessary. The disadvantages also include loading hydrogen peroxide from above, which requires adequate containment (to such a system which has an intrinsic danger) and this is not sufficiently robust and efficient with low costs.

[0015] Document WO2012029875A1 attempts to reduce the residual solution during the production of hydrogen peroxide gas. To this end, the described hydrogen peroxide production apparatus comprises: an atomizing section for atomizing a hydrogen peroxide solution stored in a storage section by applying ultrasonic vibrations to the hydrogen peroxide solution; an inner cylinder section for guiding the atomized hydrogen peroxide solution mixed with a carrier gas in an upward direction so as to discharge the hydrogen peroxide solution; an inner cylinder section having the inner cylinder section arranged in the inner space thereof to form a double-tube structure, with a gas flow passage formed between the inner and outer cylinder parts for the carrier gas flowing towards the storage part; a gas introduction section, hollow and communicating with the outer cylinder section so that the carrier gas flows into the hollow gas introduction section before flowing into the outer cylinder section; and a heater for heating the carrier gas when the carrier gas flows into the gas introduction section. However, this device is not suitable for selecting the finest aerosol drops, nor for producing aerosols at low temperatures.

[0016] There remains the need for a generator of gas (referred to as the "vapor gas") or aerosol 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.

[0017] There is also the need for a vapor gas or aerosol generator which can be used as a retrofit on existing machines which need sterilization / sanitization (or other) or for sanitizing environments. Purpose and object of the invention

[0018] It is the object of the present invention to provide a generator of vapor gas or aerosol from a liquid solution, in particular a sterilizing solution of H2O2, which solves the problems and overcomes the disadvantages of the prior art.

[0019] The present invention relates to a generator device of vapor gas or aerosol from a liquid solution according to the appended claims.

[0020] Detailed description of embodiments of the invention

[0021] List of drawings

[0022] The innovation will now be described by way of nonlimiting example, with particular reference to the figures of the accompanying drawings, in which:

[0023] - Fig. 1 shows a vertical section of the device according to an embodiment of the invention;

[0024] - Fig. 2 shows a detail of the aerosol generation section in the device in Figure 1, according to an embodiment;

[0025] - Fig. 3 shows an external view of the detail of Fig. 2;

[0026] - Fig. 4 shows the ventilation unit and the air heating unit in the device in Fig. 1, according to an embodiment;

[0027] - Fig. 5 shows a perspective view of the vertical tube and the vapor gas formation cylinder in the device in Fig. 1, according to an embodiment;

[0028] - Fig. 6 shows a section view similar to Fig. 1, in more detail, according to an embodiment;

[0029] - Fig. 7 shows a top perspective view of the outlet of the nebulizer in the device in Fig. 1 or 6, according to an embodiment.

[0030] It is here specified that elements of different embodiments can 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 .

[0031] The present description also refers to the prior art for the implementation thereof, as for 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, for example.

[0032] When an element is introduced, it is always understood that there can be "at least one" or "one or more".

[0033] 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.

[0034] The various components mentioned below can conveniently be made in one piece in groups of two or more where feasible.

[0035] "Cylindrical crown" (or "cylindrical ring") will mean hereinafter substantially a volume enclosed between two coaxial cylinders of equal height and different radius. Embodiments

[0036] Fig. 1 shows the device 1000 comprising a base 700 (e.g., resting on wheels 710), which supports a central upright 800 to which the ventilation unit 100 and the air heating unit 200 are fixed, as well as an upper crosspiece 900.

[0037] A vapor gas or aerosol gas production column is fixed between the base 700 and the upper crosspiece 900, comprising from below, along the axis z, a cylinder 400 in which the aerosol generator 470 is present, and a vertical tube 300.

[0038] With reference to Figs. 2-7, the generator 1000 of vapor gas G or aerosol AE from a liquid solution L and air A comprises a forced ventilation unit 100 fluidly connected to a heating unit 200 for air A which enters laterally into the tube 300 fluidly connected to the cylinder 400, the tube and the cylinder being coaxial along an axis z oriented, in use, along the direction of gravity.

[0039] In the cylinder 400, there are provided, from the bottom upwards:

[0040] - a nebulization unit 470 with a vibrating surface 475 facing upwards, configured to produce aerosol AE;

[0041] - an expansion chamber 460 for the liquid solution L with a flared development upwards (to minimize the volume of peroxide) from the vibrating surface 475 up to a free surface SL of the liquid solution;

[0042] - a formation chamber 410 for the aerosol AE above said free surface SL. The tube 300 is connected to said cylinder 400 at the end of said formation chamber 410 opposite to said free surface SL and extends upwards outside the cylinder. The connection can be a rigid connection and the tube can partially enter the cylinder 400. The tube 300 comprises a central channel 320 and an outer tube 310, preferably shorter than the central channel, these two forming an annular gap 360 over the length of the outer tube. The central channel has no means for heating the vapor gas G or the aerosol AE.

[0043] The heating unit 200 for air A enters laterally into the gap 360 of the tube 300 so that the air (A) is forced downwards.

[0044] In the gap 360, a plurality of fins 330 is provided, inclined downwards with respect to said axis z and equally circumferentially spaced with respect to said central channel 320. The fins could equivalently not be equidistant. Preferably, the fins are inclined at an angle of between 30° and 45°. According to a different aspect of the invention, the fins 330 are three in number. These fins serve to create an air vortex which continues to swirl in the formation chamber 410.

[0045] The gap ends towards the lower end of the tube (or of the central channel), inside the cylinder 400, with a circular ring nut 340 perpendicular to said axis and configured to push air A towards the walls of said cylinder 400. This allows creating a recirculation of air towards the center so that the aerosol AE then rises in the central channel of the tube.

[0046] During the ascent, the largest drops are directed towards the inner walls of the cylinder 400 and hit against them, falling back down, while the smallest drops are directed into the central channel of the tube at a temperature of 80-100°C, if the air is heated to about 150°C.

[0047] Once the aerosol is in the central channel, it can remain in the aerosol state if the central channel is short, or it can evaporate and become vapor gas G if the central channel is long enough. Those ordinarily skilled in the art can easily determine the length of the central channel necessary for the purpose.

[0048] Below said circular ring nut 340, an extension 350 of said central channel 320 is provided, which comprises for example two or more vertical teeth 350 equidistant (or not) in a plane transverse to said axis (more preferably three or more vertical teeth). Such vertical teeth allow the recovering of the large drops in the aerosol AE, allowing only the finest ones to rise (as a second selection, since the rising airflow still has a slight rotation).

[0049] In the upper end of the expansion chamber 460, at least one transverse bar 450 is provided, preferably at least two transverse bars, projecting with respect to the free surface of the liquid solution (L). This serves to interrupt the rotation of the liquid impressed by friction from the rotation of the air, rotation resulting in the displacement of the liquid on the walls of the container due to the centrifugal force. In fact, such a displacement would cause the decrease of the free surface of the system (e.g., fixed at 5 cm from the bottom), affecting the efficiency of the aerosol generator.

[0050] The central channel 320 opens upwards at a predetermined distance after the height of introduction of the heating unit 200 into the gap 310 and is configured to supply the vapor gas G or the aerosol AE to the outlet. In an embodiment, the central channel is kept at the inlet at about 76 degrees, while the vapor gas exits at about 36°C from above (if this is aerosol, it exits at a higher temperature since the central channel is shorter). This is a difference from traditional vapor gas / aerosol generators, which simply drop droplets of solution onto a hot plate at 150°C and a part of the droplets dissociates into water and oxygen. Moreover, with the device of the invention the losses in flow rate are considerably reduced, and therefore the device is characterized by a high efficiency.

[0051] Coming now to a greater detail of the heating unit 200 for air A, according to an optional embodiment it comprises a resistance (not shown) coiled in a spiral about a spiral axis oriented along the flow of air A, where the diameter of the spiral decreases along the spiral axis, and where at the beginning and end of the spiral two respective ovoidal elements 220,230 are positioned, which are configured to direct the air A towards the resistance. The spiral can have a circular or square section. In the latter case, four support fins 210 with external grooves 215 in which the resistance wire slides are included.

[0052] With reference to Fig. 2, in an embodiment, the liquid solution L is fed from a tank filled with hydrogen peroxide (not shown) and the level thereof is monitored in a small vertical tube in which the liquid 462 supports a float 463 the height of which is monitored by a sensor (not shown), which possibly interrupts the peristaltic pump (not shown) which pumps the liquid into the aerosol generator. A small horizontal tube, in which the liquid L 461 is introduced onto the surface of the aerosol generator 470, which is preferably a piezoelectric generator, departs from the small vertical tube. A heat sink 480 can be placed below the piezoelectric generator 470. In Fig. 3, the small vertical tube is fixed between two projecting elements 464 and 465. An overflow recirculation channel can also be provided (not shown).

[0053] The described generator device for vapor gas or aerosol AE has no moisture removal means.

[0054] Advantages

[0055] The particular dynamic pressurization / ventilation system in the device according to the invention ensures only the emission of sufficiently small, nebulized, heated droplets to be vaporized at a low temperature, i.e., preferably at about 36° (this temperature can vary depending on the length of the central channel). 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).

[0056] The generator of aerosol from a liquid solution, in particular hydrogen peroxide, according to the innovation is adjustable and compact.

[0057] 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 (air) 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.

[0058] The generator according to the innovation and the circuit in which it is inserted can be used in all those fields where aerosol or H2O2 gas (generally vapor gas) 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.

[0059] The preferred embodiments of the present innovation have been described above, but it is to be understood that those skilled in the art may make modifications and changes without departing from the scope of protection thereof, as defined in the appended claims.

Claims

CLAIMS1) A device (1000) for generating vapor gas (G) or aerosol (AE) from a liquid solution (L) and air (A), comprising a forced ventilation unit (100) fluidly connected to an air heating unit (200) (A) which enters laterally into a tube (300) fluidly connected to a cylinder (400), the tube and the cylinder being coaxial along an axis (z) oriented, in use, upwards along the direction of gravity, wherein in the cylinder (400) there are provided from the bottom upwards:- a generation unit (470) for vapor gas (G) or aerosol with a vibrating surface (475) facing upwards, configured to produce a vapor gas (G) or aerosol (AE);- an expansion chamber (460) of the liquid solution (L) with a flared development upwards from the vibrating surface (475) up to a free surface (SL) of the liquid solution;- a formation chamber (410) for the vapor gas (G) or aerosol (AE) above said free surface (SL); and wherein the tube (300) is connected to said cylinder (400) at the end of said formation chamber for vapor gas (G) or aerosol (410) opposite to said free surface (SL) and extends upwards outside the cylinder, and wherein:- the tube (300) comprises a central channel (320) and an outer tube (310), which form an annular gap (360) therebetween;- the heating unit (200) for air (A) enters laterally into the annular gap (310) of the tube (300) sothat the air (A) is forced downwards;- in the annular gap (360) a plurality of fins (330) is provided, inclined downwards with respect to said axis (z) and equally circumferentially spaced with respect to said central channel (320);- the annular gap (360) ends downwards with a circular ring nut (340) perpendicular to said axis and configured to push the air (A) towards the walls of said cylinder (500);- in the upper end of the expansion chamber (460) at least one transverse bar (450) is provided, projecting with respect to the free surface of the liquid solution (L);- said central channel (320) has an outlet upwards at a predetermined distance after the height of introduction of the heating unit (200) into the gap (360), the length of said central channel (320) being configured to supply the vapor gas (G) or the aerosol (AE) to the outlet;- said central channel has no heating means for the vapor gas (G) or the aerosol (AE).2) The device (100) according to claim 1, wherein the fins of said plurality of fins (330) are inclined at an angle of between 30° and 45°.3) The device (1000) according to claim 1 or 2, wherein the fins of said plurality of fins (330) are three in number.4) The device (100) according to one or more of claims 1 to 3, wherein an extension (350) of said central channel (320) is provided below said circular ring nut(340).5) The device (100) according to claim 4, wherein said extension (350) of said central channel (320) comprises two or more vertical teeth (350) equally circumferentially spaced in a plane transverse to said axis.6) The device (100) according to claim 5, wherein said extension (350) of said central channel (320) comprises three or more vertical teeth (350) equally circumferentially spaced in a plane transverse to said axis.7) The device (100) according to one or more of claims 1 to 6, wherein the heating unit (200) for air (A) comprises a resistance coiled in a spiral about a spiral axis oriented along the flow of air (A), wherein the diameter of the spiral decreases along the spiral axis, and wherein at the beginning and end of the spiral two respective ovoidal elements (220,230) are positioned, which are configured to direct the air (A) towards the resistance.8) The device (100) according to one or more of claims 1 to 7, wherein two transverse bars (450) are provided in the upper end of the expansion chamber (460) at the free surface (SL) of the liquid solution (L).9) The device (100) according to any one of claims 1 to 8, wherein the liquid solution (L) is fed from a tank filled with hydrogen peroxide.10) The device (100) according to any one of claims 1 to 9, wherein the generation unit (470) for vapor gas (G) or aerosol is a piezoelectric generator.11) A generator (100) of vapor gas (G) or aerosol (AE) according to any one of claims 1 to 10, wherein the outer tube (310) is shorter than the central channel (320).

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