EP2496363A1

EP2496363A1 - Mist generation device

Info

Publication number: EP2496363A1
Application number: EP10702520A
Authority: EP
Inventors: Frédéric GOESSENS
Original assignee: Gloster Europe SAS
Current assignee: Gloster Europe SAS
Priority date: 2009-01-13
Filing date: 2010-01-12
Publication date: 2012-09-12
Also published as: MX2011007481A; JP2012515071A; WO2010094845A1; RU2011134070A; BRPI1007368A2; FR2940923A1; US20110266376A1; CN102307669A; AU2010215339A1; FR2940923B1; CA2749414A1

Abstract

The invention relates to a fractioning injector in particular for a Venturi-type mist generation device, comprising a main vein successively comprising an axial convergent vein (3) for receiving a pressurised gas flow, a cylindrical vein (5) and an axial divergent vein (7), said injector further comprising a substantially transverse secondary vein (9) for a liquid flow inlet and opening downstream from the convergent vein (3), characterised in that the axis (zz') of the cylindrical vein (5) is angularly offset relative to the longitudinal axis (xx') of the convergent (3) and divergent (5) veins. The invention also relates to injection devices and to mist generation apparatuses using such an injector.

Description

APPARATUS FOR FOGGING

The present invention relates to a fractionation injector, in particular intended to equip injection devices of the type used on decontamination apparatus by misting a disinfection product on surfaces to be treated, and in particular on the walls of a housing. local area and the different devices and instruments contained in it. The present invention also relates to misting devices able to generate and propel in the room to be treated fine droplets forming therein a type of mist called "dry fog".

It is known that the bacterial agents that cause the contamination and are suspended in the air of a room tend to sediment on the various surfaces and objects contained therein. It is also known that, conversely, bacterial agents that develop on the objects and on the walls of a room, (for example, operating theaters, clean rooms or other medical rooms, etc.) have tendency to suspend in the atmosphere. These premises are thus in a situation of permanent exchange between the walls and objects on the one hand and the atmosphere on the other hand.

It has been proposed to ensure the overall decontamination, that is to say of both the atmosphere and the walls and various objects of a room, by spraying in the volume of the latter a disinfectant product. This type of projection treatment has been found to have several disadvantages.

Firstly, the size of the drops formed is relatively high (of the order of 80 to 200 microns for an air flow rate of 3 to 5 ml of air per minute), so that these drops are deposited by simple effect of gravity on the surfaces close to their place of spraying, which, of course, is not satisfactory to the extent that surfaces remote from the spray nozzle are untreated.

Secondly, because of the size of the drops, they tend to cluster and form on the surface of the walls and objects of the local a wet film, or even puddles of liquid.

It has been proposed in patent FR 2 859 650 in the name of the applicant, to improve the fractionation of sprayed drops by using an injection device for obtaining fine droplets whose dimensions are of the order of 2 micrometers to 20 microns and thus have the property of being suspended in the entire volume of the room and to be deposited on the walls and objects contained therein without agglomerating them so that they form a continuous film; the fog thus generated being called "dry fog".

Thus the injection device according to patent FR 2 859 650 comprises: a secondary vein connected to means for supplying said liquid and comprising means for producing a first fractionation of said liquid and an expansion chamber,

a main stream connected to means for generating a gas flow comprising means for performing a second fractionation of said liquid and an outlet orifice to the atmosphere,

means for joining said secondary vein to said main vein connecting the expansion chamber and the means for producing the second fractionation of said liquid.

According to a particularly advantageous variant of this invention, the injection device is provided with an ultrasonic "resonator" disposed downstream of the exit of the injector, so that the flow output of it is subject to fragmentation forming a kind of "diffraction" of the drops, having the effect of making them even smaller, which allows to further increase the homogeneity of their distribution.

Such an injection device, if it allows to distribute regularly throughout the volume of a local fine droplets of the treatment product, however, has certain disadvantages.

First, the ultrasonic resonator disposed downstream of the outlet of the injector must of course be held in position by a support connected to the spraying device. However, it has been found that this support had the effect of causing an uncontrolled diffusion of the spray jet output that harmed the good regularity of it. In order to minimize this disadvantage, it has been ensured that the support is as thin as possible, but this makes it particularly vulnerable to shocks and other stresses to which it is subjected during use, so much so that its position at the head of the device further increases this vulnerability.

It is also noted that, during operation, droplets of the spray liquid accumulate on the support, and contribute to the formation of drops of liquid which are sprayed with the fine droplets of the main jet.

Finally, the presence of the resonator at the head of the injector prevents the integration thereof into certain processing machines in which it is desired to have a total embedding of the spray means.

The object of the present invention is to propose a spray injector capable of generating a dry mist and of distributing it in a homogeneous and regular manner in ^

the entire volume of a room without it being necessary to use an ultrasonic resonator.

The subject of the present invention is thus a fractionation injector, in particular for a venturi-type misting device, of the type comprising a main vein successively constituted by a convergent axial vein intended to receive a stream of gas under pressure, a cylindrical vein, and a divergent axial vein, said injector further comprising at least one secondary vein, substantially transverse, intended to admit a flow of treatment liquid, and which opens downstream of the convergent vein, characterized in that the axis of the cylindrical vein is angularly offset with respect to the longitudinal axis of the convergent and divergent veins.

Interestingly, the secondary vein will open into the upstream part of the divergent vein.

Preferably the angular offset will be between 2 ° and 8 ° and will preferably be close to 4 °. Moreover, the respective lengths of the convergent vein and the diverging vein will preferably be substantially equal. As for the length of the cylindrical vein it may be equal to about half the length of the convergent vein and, more precisely, of the order of 0.4 times this one.

According to the invention, the conicity of the convergent may be between 40 ° and 50 ° and will preferably be close to 46 ° and the conicity of the divergent may be between 10 ° and 20 ° and will preferably be close to 15 °.

Finally, the diameter of the cylindrical vein connecting the convergent and the divergent may be between 0.9 and 1.5 mm and preferably be close to 1.3 mm. The present invention also aims to provide an injection device capable of implementing such an injector.

The subject of the present invention is thus an injection device of the type comprising a body pierced with a cylindrical axial channel supplied at one of its ends by a gaseous flow under pressure and receiving at its other end a fractionating injector. as described above, said body being provided with at least one intake duct of a treatment liquid opening into a distribution chamber in communication with the secondary vein of the injector.

Preferably, the axis of the intake duct will be substantially perpendicular to the longitudinal axis of the axial duct. Moreover, the intake duct of the treatment liquid will advantageously be provided, in its downstream part, with a calibrated orifice for flow control.

Finally, according to the invention the distribution chamber may be formed between the outer surface of an insert resting on the injector which will be pierced with an axial gaseous supply channel thereof, and the inner surface a chambering made in the body.

Another object of the present invention is to provide an autonomous misting apparatus capable, after a given operating time in a room, of eradicating any bacterial germ both in the atmosphere and on the surfaces of the walls and objects thereof. .

The present invention thus also relates to a misting apparatus comprising a fractionation injector of the type described above, disposed in an injection device and comprising means for pressurizing the air flow supplying the main stream of the injector. which are controlled by electronic control means, and means for feeding the vein secondary treatment liquid of which at least the volume to be dispensed during a treatment operation is measured by said electronic control means.

Preferably the electronic control means may consist of a microcontroller, and the treatment liquid supply means may be constituted by a metering pump capable of taking from a storage tank of the treatment liquid a determined volume of the latter. and to deliver it to a temporary storage tank from which it will be sucked by the venturi effect from said secondary vein of the injector.

The present invention also relates to the application of a misting apparatus as mentioned above, the spraying in a room to be treated with a treatment product having at least one decontamination effect.

An embodiment of the present invention will be described hereinafter by way of nonlimiting example, with reference to the appended drawing in which:

FIG. 1 is a diametrical sectional view of a fractionation injector according to the invention,

FIG. 2a is a longitudinal sectional view of an injection device used in a misting apparatus according to the invention, using an injector of the type shown in FIG. 1,

FIG. 2b is a perspective view of the injection device represented in FIG. 2a; FIG. 3 is a curve representing the flow rate respectively delivered by an injection device according to the prior art and by a device for injection; injection according to the invention, depending on the pressure of the propellant gas in the main vein, FIG. 4 is a representation in schematic form of a misting apparatus according to the invention implementing an injection device of the type shown in FIGS. 2a and 2b,

FIG. 5 is a curve representing the speed of the gas / liquid flow at the outlet of an injector according to the invention as a function of the angle formed by the axis of the cylindrical part thereof with the longitudinal axis of the converge and diverge from the injector.

FIG. 1 shows a fractionation injector 1 according to the invention, which is formed of a cylindrical body of longitudinal axis xx 'and whose anterior face is of smaller diameter. The injector 1 is traversed from one side by a venturi type longitudinal flow vein, comprising three parts, namely a convergent 3, followed by a cylindrical portion 5 which is extended by a diverging opening 7 on the outside .

In the present embodiment of the invention the conicity of the convergent 3 is 46 ° and its inlet has a diameter of 4.78 mm. The cylindrical portion 5 extending the convergent 3 has a diameter of 1.3 mm and the diverging 7 extending thereof has a taper of 15 ° and an outlet of 2.27 mm.

Moreover, the convergent 3 and the divergent 7 have their respective axes which merge with the longitudinal axis xx 'of the injector 1. The cylindrical portion 5 has its axis zz' which is angularly offset with respect to the longitudinal axis xx 'and forms therewith an angle α whose value, in the present embodiment of the invention, is preferably of the order of 4 ° but which can be understood, depending on the uses, between 2 ° and 8 °. The point 0 from which the relative rotation of the axis zz 'of the cylindrical part 5 is effected by relative to the longitudinal axis xx 'lies substantially in the middle of the cylindrical portion 5 and, in the embodiment shown, at a distance of 4.95 mm from the upstream face Ib of the injector 1.

The body of the injector 1 is traversed by transverse channels 9, of which there are four in the present embodiment, but it could also be possible to use a single channel or, on the contrary, a larger number of channels. . These channels 9, which open into the main stream downstream of the cylindrical portion 5, are in communication with liquid supply and flow control means that it is desired to distribute, as explained below.

Thus the propellant gas, which most of the time may consist of air but which could also, for certain specific applications, be made of any other gas, is pressurized, for example by means of a compressor capable of applying at the inlet of the venturi a pressure of the order of 3.10 ⁵ Pa in the present example, then brought to the inlet of the convergent 3 in which, in known manner, it undergoes an increase in its speed and a decrease in its pressure by venturi effect , so that at the outlet of the cylindrical portion 5 the liquid to be dispensed is sucked by the transverse channels 9 to be projected into the room, mixed with the propellant.

According to the present invention, it has surprisingly been found that the angular offset α of the axis zz 'of the cylindrical portion 5 relative to the axis xx' of the convergent 3 and of the divergent portion 7 has the effect of creating a splitting particularly effective droplets suspended in the gas stream.

FIGS. 2a and 2b show an injection device using such a fractionation injector according to the invention. This device comprises a body 11 at the front of which is screwed an injector body 13 in which is positioned an injector 1 according to the invention, so that the longitudinal axis xx 'thereof is merged with that of the body 11.

The injector body 11 is pierced with a central and longitudinal channel 12 in which takes place a cylindrical spacer 14 which keeps the injector 1 in position. This spacer is pierced with a central and longitudinal channel 15 of the same diameter as the inlet of the convergent 3 and which, at one of its ends, opens into the latter, and at its other end is supplied with gas under pressure by an intake nozzle 17.

The median part of the body 11 is hollowed out with a bore 19 making it possible to create between the inner surface thereof and the outer surface of the spacer 14 a distribution chamber 21 which is in communication, via longitudinal channels 22, with the transverse channels 9 of the injector 1.

The middle part of the body 1 is also pierced with transverse threaded holes in which its screw-fastened two tubular elements 23 for supplying treatment liquid which are arranged symmetrically with respect to the longitudinal axis xx 'of the body 11. These tubular elements are pierced with a central channel 25 which opens into the distribution chamber 21 and which ends with a calibrated stream 27 for controlling the flow of the treatment liquid admitted into the distribution chamber 21. In order to promote the adaptation of the device to the various treatment situation, including the specific volumes of different premises to be treated, the two calibrated veins 27 may for example have different passage sections, in particular of the order of 0.15 mm ² and 0.60 mm ² , thus making it possible to use one or the other or the two calibrated veins, which makes it possible to have - an overall passage section of 0.15 mm ² , 0.60 mm ² , or 0.75 mm ² .

According to the invention, the gas arriving via the central vein passes through the convergent 3 in which it undergoes a decrease in pressure by the venturi effect, then the cylindrical part 5 in which, because of the misalignment of the latter, it is subjected to vortices generating during suction of liquid through the transverse channels 9, a further fractionation of the liquid admitted.

It has been found that the fractionation thus produced by means of the injector 1 according to the invention makes it possible to generate a mist whose droplets which form it are extremely fine and which, moreover, are distributed homogeneously in the space without agglomeration between them so that they form a dry fog.

The present invention is interesting in that it makes it possible to increase the speed of the liquid / gas flow at the outlet of the injector, which has the advantage of allowing the flow to reach areas further away from the apparatus and to limit or even eliminate its wetting effect. FIG. 5 shows the variation of the speed of the liquid / gas flow at the outlet of the injector, as a function of the angle α formed by the axis of the cylindrical portion 5 of the injector with the longitudinal axis xx 'thereof. It can be seen that, in the present embodiment, if the speed passes through a maximum for an α offset of 4 °, a speed increase is also obtained for shifts of between 2 ° and 8 °.

The present invention is also particularly interesting in that it makes it possible, in particular because of the suppression of the resonator, to reduce the pressure of the propellant gas in the main vein. Thus, when according to the prior state of the art, in the devices injection using resonators, the optimum operating pressure in the main vein is generally between 2.8.10 ⁵ Pa and 3.2.10 ⁵ Pa, this pressure in the injector according to the invention is between 1 5.10 ⁵ Pa and 3.5.10 ⁵ Pa and preferably close to 2.10 ⁵ Pa. Note that such a provision has significant advantages.

Indeed, it makes it possible to reduce the energy required and therefore the power of the pressurizing means of the gas flow admitted into the main stream, and therefore that of the compressor used which, at the same time, makes it possible to reduce the noise produced by this one as well as its size and its cost.

It is also known that in the prior art decontamination apparatus using venturi-type injection devices, the value of the pressure of the gas, especially air, in the main vein It has to be set very precisely, which in practice is not without serious problems with the calibration of the installations, which sometimes necessitates adjustments at the point of use. Indeed, as shown in curve a) of FIG. 3, which represents the variation of the gas flow rate in the main vein as a function of the pressure in this vein, it can be seen that, at the operating pressure, either for a pressure of the order of 2.8 × ¹⁰ ⁵ Pa, a slight decrease in pressure, for example 0.75 × 10 ⁵ Pa, changes the flow rate from a value of 30 ml / min to a value of about 50 ml / min. a variation representing approximately 66% of its initial value.

On the contrary, on the curve b) representing the same parameters for a misting apparatus according to the invention, the same pressure decrease made to the ^

around the operating pressure, or around 2.10 ⁵ Pa, generates a decrease in flow rate of about 3ml / min or about seven times less than previously.

Thus, the present invention makes it possible to improve in a particularly efficient way the regularity of operation of the devices of this type, making it possible in particular to avoid a number of adjustments and adjustments which, in the meantime, were imperatively to be carried out in situ.

FIG. 4 shows schematically an example of a misting apparatus implementing an injection device using a fractionation injector according to the invention.

On this device the rear part of the injection device 11 is supplied with pressurized air by a compressor 30 which is controlled by electronic control means such as in particular a microcontroller 32. This microcontroller is interface with a control panel

33 allowing the user to provide the various parameters, such as in particular the volume of the room, which are necessary for him to control the processing operation.

The treatment liquid is stored in a cartridge

34 in which the volume V determined as necessary for the processing operation to be performed by the microcontroller 32, is taken by means of a metering pump 36, for example a peristaltic pump, whose operation is controlled by the microcontroller 32, for delivered to a temporary storage tank 38. The latter is joined at the inlet of the tubular elements 23. When the desired volume V has been transferred into the reservoir 38, the microcontroller 32 controls the start-up of the compressor 30 in order to start the processing and, when the tank 38 is emptied, the microcontroller stops. Of course the injector according to the invention could be used with decontamination devices of different structure and layout. It could also find applications in areas other than decontamination, and could be used in a variety of applications where it is necessary to generate tiny droplets that can form a dry fog.

Claims

1 - Fractionation injector, in particular for venturi misting device, of the type comprising a main vein successively consisting of a convergent axial vein (3) intended to receive a flow of gas under pressure, a cylindrical vein (5), and a diverging axial vein (7), said injector further comprising at least one secondary vein (9), substantially transverse, intended to admit a flow of treatment liquid, and which opens downstream of the convergent vein (3), characterized in the axis (zz ') of the cylindrical vein (5) is angularly offset with respect to the longitudinal axis (xx') of the convergent (3) and divergent (5) veins.

2 - fractional injector according to claim 1 characterized in that the secondary vein (9) opens into the upstream portion of the diverging vein (7).

3 - fractional injector according to one of claims 1 or 2 characterized in that the angular offset (α) is between 2 ° and 8 ° and is preferably equal to about 4 °.

4 - Fractionation injector according to one of claims 1 to 3 characterized in that the respective lengths of the converging vein (3) and the diverging vein (7) are substantially equal.

5 - Fractionation injector according to one of claims 1 to 4 characterized in that the length of the cylindrical vein (5) is equal to about half the length of the converging vein (3) and, more specifically, of the order of 0.4 times this one.

6 - Injector fractionation according to one of claims 1 to 5 characterized in that the conicity of the convergent (3) is between 40 ° and 50 ° and preferably close to 46 °. 7 - Fractionation injector according to one of claims 1 to 6 characterized in that the conicity of the divergent (5) is between 10 ° and 20 ° and preferably close to 15 °.

8 - Fractionation injector according to one of claims 1 to 7 characterized in that the diameter of the cylindrical vein is between 0.9 and 1.5 mm and preferably close to 1.3 mm.

9 - Injection device of the type comprising a body (11) pierced with a cylindrical axial channel (15) supplied at one of its ends by a gaseous flow under pressure and receiving at its other end a fractionating injector (1) according to one of claims 1 to 8, said body being provided with at least one conduit (23) for admission of a treatment liquid opening into a distribution chamber (21) in communication with the secondary vein (9) of the injector (1).

10 - Injection device according to claim 9 characterized in that the axis of the intake duct (23) is substantially perpendicular to the longitudinal axis (xx ') of the axial channel (15).

11 - Injection device according to one of claims 9 or 10 characterized in that the inlet conduit of the treatment liquid is provided in its downstream portion, a calibrated orifice (27) for flow control.

12 - Injection device according to one of claims 9 to 11, characterized in that the distribution chamber (21) is formed between the outer surface of an insert (14) resting on the injector (1) and pierced with an axial gaseous feed channel thereof, and the inner surface of a recess (19) formed in the body (11).

13 - Misting apparatus comprising a fractionation injector according to one of claims 1 to 8, disposed in an injection device according to one of claims 9 to 11, and comprising means for setting pressure (30) of the air stream feeding the main stream of the injector (1) which are controlled by electronic control means (32), and supply means (36,38) of the secondary vein (9). ) in treatment liquid of which at least the volume (V) to be dispensed during a treatment operation is measured by said electronic control means (32).

14 - Misting apparatus according to claim 13 characterized in that the electronic control means consist of a microcontroller (32).

15 - Misting apparatus according to one of claims 13 or 14, characterized in that the treatment liquid supply means consist of a metering pump (36) adapted to take in a storage tank of the treatment liquid a volume (V) of the latter and deliver it to a temporary storage tank (38) from which it is sucked by the venturi effect from said secondary vein (9) of the injector d) •

16 - Application of a misting device according to one of claims 13 to 15 for spraying in a room to be treated with a treatment product having at least one decontamination effect.