WO2010149881A1

WO2010149881A1 - Method for manufacturing and controlling a misting injector

Info

Publication number: WO2010149881A1
Application number: PCT/FR2010/000466
Authority: WO
Inventors: Frederic Goessens
Original assignee: Gloster Europe
Priority date: 2009-06-25
Filing date: 2010-06-24
Publication date: 2010-12-29
Also published as: FR2947192A1; FR2947192B1

Abstract

The present invention relates to a method for manufacturing an atomizing injector, in particular for a misting device, in a machining center according to specifications. Said injector comprises at least one main duct successively consisting of a convergent axial duct, a cylindrical duct, and a divergent axial duct, the axis of the cylindrical duct being angularly offset in relation to the longitudinal axis of the convergent and divergent ducts. The disclosed method is characterized in that it comprises the steps of: setting the machining center according to the dimensions defined in the specifications; checking, according to the specification, the dimensional values of injectors thus produced; modifying the settings of the machining center if said values are not acceptable; - when said values are acceptable, proceeding with functional trials of the injector; - verifying the values of the operating parameters; - when one of the operating parameters is not acceptable, modifying at least one setting of the machining center until said parameter complies with the specifications.

Description

Method of manufacturing and controlling a misting injector

The present invention relates to a method for manufacturing and qualification of a fractionation injector, in particular for equipping injection devices of the type used on decontamination apparatus by misting a disinfectant on surfaces to be treated. , and especially on the walls of a room. 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. We also know that, conversely, bacterial agents that develop on the objects and on the walls of a room, (for example operating rooms, clean rooms or various care etc. ..) tend 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 gravity effect on the surfaces close to their spraying place, which, of course, is not satisfactory insofar as the surfaces remote from the spray nozzle are free of treatment. 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".

The improved fractionation required to obtain such a dry mist may according to this patent be advantageously obtained by means of an ultrasonic "resonator" which is disposed downstream of the outlet of the injector, so that the output flow of it is subjected to a fragmentation forming a kind of "diffraction" of the drops, having the effect of making them even smaller, which makes it possible 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 inconvenience, 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, especially as its position at the top of the device further increases this vulnerability.

That is why the Applicant has proposed in Application FR 09.00134 another means for creating a fractionation of the spray jet for generating a dry mist and distribute it evenly and regularly throughout the volume of a room without any it is necessary to use an ultrasonic resonator.

According to this invention the fractionation injector comprises a main vein successively consisting of a convergent axial vein intended to receive a flow of pressurized gas, a cylindrical vein, and a divergent axial vein, said injector further comprising at least one vein secondary, substantially transverse, intended to admit a flow of treatment liquid, and which opens downstream of the convergent vein, this injector being characterized in that the axis of the cylindrical vein is angularly offset relative to the longitudinal axis of veins convergent and divergent. It is understood that the quality of the spray produced by means of such an injector is closely related to the quality of realization of the flow veins.

Now it is in this case to perform a machining ducts of very small dimensions and, moreover, ducts, one of which is inclined relative to the longitudinal axis of the injector.

On a general level, it is known that in the field of machining, a part is made from dimensions to which manufacturing tolerances are applied. defined in a specification. During the machining process, the production machine is set so that the dimensions of the parts produced are within the tolerance ranges defined in these specifications. The manufacturing process usually ends with a control step during which it is determined whether this is the case.

However, when such a manufacturing method is implemented on small products such as the injector concerned by the present invention, the control phase requires the use of sophisticated measuring means at the cutting edge of technology. such as three-dimensional analysis by micro-tomography. Such a situation has significant disadvantages.

In addition to the fact that the metrology means used are very expensive, they are more particularly long to implement, some parts analysis processes may require more than a day's work. Under these conditions the production means are stopped during this period of time, waiting to know if the settings adopted by the machining means are or not acceptable. This period of qualification qualification time being renewed of course with each of the modifications of the adjustment made, it is understood that the capital costs of the production tool quickly become prohibitive.

US Patent 3983376 discloses a method of manufacturing parts by means of a machining center in which, after having manufactured the latter, their dimensional values are checked and the adjustment of the machining center is then modified. depending on the verification performed. However, the steps of implementing this method are not followed by a step in the course of which functional tests of the part are carried out by checking the values of the operating parameters of said part and, in the event that one of these does not conform to the specifications, at least one machining center settings until this parameter becomes compliant.

The object of the present invention is to remedy these drawbacks by proposing a method making it possible to manufacture such an injector rapidly and efficiently. The present invention thus relates to a manufacturing method by a machining center and according to a specification, a fractionation injector, in particular for misting device, of the type comprising at least one successively constituted main vein a convergent axial vein, a cylindrical vein, and a divergent axial vein, the axis of the cylindrical vein being angularly offset with respect to the longitudinal axis of the convergent and divergent veins, characterized in that includes the following steps: - adjust the machining center according to the dimensions defined in the specifications, check, according to the specifications, the dimensional values of injectors thus produced,

- modify the settings of the machining center if these values are not acceptable,

- when these values are acceptable, carry out functional tests of the injector,

- check the values of the operating parameters,

- when one of the operating parameters is not acceptable, modify at least one setting of the machining center until this parameter complies with the specifications.

Preferably, the manufacturing method according to the invention will comprise a control step consisting of: introducing into said cylindrical vein a pin calibrated to the diameter thereof,

positioning the spindle longitudinally in the cylindrical vein so that at least one end thereof extends beyond the injector,

- Check the good realization of the cylindrical vein from the said end.

In an interesting variant of the invention, a pin will be used whose length will be greater than that of the injector. Such an arrangement will position this pin in the cylindrical vein of the injector so that its two ends protrude from it, which will improve the accuracy of the controls to the extent that they can then be made to two ends of said pin.

In addition, the diameter of the cylindrical vein can be controlled by using a pin whose diameter of the body adapted to fit in the cylindrical vein will represent the lower adjustment tolerance and one of the ends will represent the higher adjustment tolerance.

One 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 logic diagram illustrating the various steps of the manufacturing method according to the invention; invention,

FIG. 2 is a longitudinal and transverse sectional view of an injector according to the invention, FIG. 3 is a longitudinal and transverse sectional view of the injector shown in FIG. 1, a control pin being in place in FIG. the bore forming the cylindrical vein, Figures 4 and 5 are views in longitudinal and transverse section showing two alternative embodiments of the method according to the invention.

FIG. 2 shows a fractionation injector 1 according to the invention, which is formed of a cylindrical body of longitudinal axis xx '. 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 of the order of 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 'that is to say that it forms with it 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 use, between 2 ° and 8 °. The point O from which the relative rotation of the axis zz 'of the cylindrical part 5 with respect to the longitudinal axis xx' is situated is substantially in the middle of the cylindrical part 5 and, in the mode of implementation illustrated, 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, four in number in the present embodiment, but one could also use a boy Wut

single channel or, on the contrary, to a larger number of channels. These channels 9, which open into the main stream downstream of the cylindrical portion 5, are in communication with supply and flow control means of the liquid that is to be dispensed.

Due to the small dimensions and the inclined disposition of the vein 5 the measurements of the orientation of its axis zz 'are difficult to achieve. FIG. 1 shows a logic diagram illustrating the various steps of the manufacturing method according to the invention.

In a first step of this one proceeds to a first adjustment of the machining center in a conventional manner, according to the dimensions and tolerances defined in the specifications and produces test pieces from these settings.

In a second step of this method, a check is made of these first parts made by simple and fast measuring means of conventional type.

To do this, it is possible, for example, as shown in FIG. 3, to introduce into the vein 5 a pin 8 whose diameter is sufficiently close to the diameter of the latter so that it can be slidably mounted in said vein 5 Then pin 8 is placed so that it protrudes at least one of its ends from insert 1. This part, on the right in FIG. 3 in the present example, is thus accessible, and its positioning relative to the insert and especially with respect to the longitudinal axis xx 'thereof, can be easily determined by suitable measuring devices, such as comparator, palmer, caliper, profile projector etc .. .

In the case of use of a profile projector, for example, the periphery S of the injector 1 and the corresponding part T can be used as a reference. of the pin 8 and thus control the value of the angle α as shown in Figure 3. It can also take as a reference surface the surface s of the cross section of the insert and the surface t_ of the cross section of pin 8.

The accuracy of this measurement can be further improved by performing this at both ends of the pin 8. For this purpose we will use a pin whose length will be greater than that of the insert so that, as well as shown in Figure 4, it can protrude from it at both ends.

The control carried out during this step can also relate to the diameter of the cylindrical vein 5. For this purpose, as shown in FIG. 5, the body thereof will advantageously be divided into two parts of slightly different diameters. namely a part 8a and a part 8b of shorter length; the difference in diameter representing the tolerance of adjustment δe admissible. The part 8a of greater length will have a diameter representing the value of the maximum diameter d - the value of the tolerance δe _^ is: d-δ_e and the diameter of the part 8b will be equal to the maximum value d. Thus part 8a will correspond to the lower adjustment tolerance and part 8b will correspond to the higher adjustment tolerance. Under these conditions when a vein 5 to be controlled will comply with the desired manufacturing tolerances part 8a will be able to enter the vein 5 and the other part 8b will not be able to enter it. During a third step, and depending on the result of the measurements made, the settings of the machining center will be modified, if necessary, until the dimensions of the part measured in a conventional manner are revealed. satisfactory in view of the manufacturing tolerances imposed by the specifications.

A fourth step of the method is then launched, namely a so-called functional control step. That is to say that the injector 1 to be tested is placed in a specific assembly making it possible to operate it under real conditions of use. Thus pressurized air is fed 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 the venturi effect, so that at the outlet of the cylindrical part 5 the liquid to be dispensed is sucked through the transverse channels 9 to be projected into the room, mixed with the air propellant.

The actual quality of the vaporization, that is to say, in particular the flow rate and the speed of the outlet air, the particle size of the sprayed liquid, the absence of the deposition of large droplets and the appearance of the spray jet are then checked. spraying, that is to say the continuity of it, its orientation and its dispersion. Depending on the quality of the results obtained, it is then possible to intervene during a fifth step, on the various physical parameters able to correct these defects and, once they are between the tolerance limits specified in the specifications. we are then able to switch to series production.

Claims

1.- Method of manufacture by a machining center and according to a specification, a fractionation injector, in particular for misting device, of the type comprising at least one main vein successively consisting of an axial vein convergent (3), a cylindrical vein (5), and a divergent axial vein (7), the axis (zz ') of the cylindrical vein (5) being angularly offset with respect to the longitudinal axis ( xx ') converging veins (3) and divergent (5), characterized in that it comprises the steps of: - adjusting the machining center according to the dimensions defined in the specifications, check, depending on the specifications, dimensional values of injectors thus produced, modify the settings of the machining center if these values are not acceptable,

- when these values are acceptable, carry out functional tests of the injector,

- check the values of the operating parameters,

2. A method of manufacturing a fractionation injector according to claim 1 characterized in that it comprises a control step consisting of:

introducing into said cylindrical vein (5) a pin (8) calibrated to the diameter thereof, - Position the spindle (8) longitudinally in the cylindrical vein (5) so that at least one end of it protrudes from the injector,

- Check the good achievement of the cylindrical vein from the control of the said end.

3. A method of manufacturing a fractional injector according to claim 2 characterized in that one uses a pin (8) whose length is greater than that of the injector.

4. A method of manufacturing a fractional injector according to claim 3 characterized in that the pin (8) is positioned in the cylindrical vein (5) of the injector so that its two ends protrude from the latter. this.

5. A method of manufacturing a fractional injector according to one of the preceding claims characterized in that one uses a pin (8) whose diameter of the body adapted to fit in the cylindrical vein represents the tolerance of lower adjustment and one end represents the higher adjustment tolerance.