EP0088029A1 - Device for producing and applying foam - Google Patents

Abstract

1. Apparatus for the production and application of foam comprising : - a chamber (1) capable of containing the liquid (4) from which the foam is prepared and - a line (5) which can be connected via release means (6) to a source of compressed gas and capable of conveying this compressed gas to a mixing chamber (13) through a first pipe (10), the mixing chamber which is connected to the body of the liquid by a second pipe (15) being arranged so that the stream of compressed gas conveyed through the first pipe meets the stream of liquid conveyed by the second pipe there, thus creating the foam, a third pipe (17) conveying the foam formed to means for applying it to the parts to be treated, said apparatus being characterised in that it comprises a fourth pipe (9) conveying the compressed gas to the interior of the chamber which is thus subjected to pressure, in that a diaphragm (16) is placed on the second pipe creating a loss of charge therein and in that the value of the diameter of the diaphragm is selected as a function of the value of the pressure applied downstream of the release means such that for a given product, the foam is formed inside the mixing chamber by injection of the treatment product in the stream of compressed gas.

Description

The subject of the invention is an apparatus for producing and applying foam, in particular intended for degreasing and disinfecting premises in the food industry, as well as for all applications where the presence of foam is desired, such as cleaning. and dyeing textiles, cements and others.

It is known to carry out the degreasing and disinfection operations of premises in the food industry by applying, to at least certain parts of these premises, foams based on liquid treatment products, in particular alkaline products which are degreasers and acidic or chlorinated products which are disinfectants.

The apparatuses hitherto used to manufacture the foams in question are complicated, expensive and involve complex adjustments.

The object of the invention is, above all, to remedy these drawbacks and to provide the user with simple, robust apparatus which is easy to adjust.

• - une enceinte propre à contenir, sous une pression déterminée, le liquide à partir duquel est préparée la mousse et
• - une conduite adaptable, par l'intermédiaire de moyens de détente, à une source de gaz comprimé et propre à acheminer ce gaz comprimé en parallèle à l'intérieur de l'enceinte par une première tubulure et à une chambre de mélange par une deuxième tubulure, la chambre de mélange, qui est reliée au sein du liquide par une troisième tubulure sur laquelle est placé un diaphragme qui crée une perte de charge dans la troisième tubulure, étant agencée de façon telle que le courant de gaz comprimé acheminé par la deuxième tubulure y rencontre le courant de liquide acheminé par la troisième tubulure générant ainsi la mousse, une quatrième tubulure acheminant la mousse formée à des moyens d'application de celle-ci sur les parties à traiter,
• - la valeur du diamètre du diaphragme étant choisie en fonction de la valeur de la pression appliquée en aval des moyens de détente de façon telle que, pour un produit donné, la mousse se forme à l'intérieur de la chambre de mélange par injection du produit de traitement dans le courant de gaz comprimé.

This apparatus is characterized by the fact that it comprises in combination:

• - an enclosure capable of containing, under a determined pressure, the liquid from which the foam is prepared, and
• - a line adaptable, by means of expansion means, to a source of compressed gas and suitable for conveying this compressed gas in parallel inside the enclosure by a first tube and to a mixing chamber by a second tubing, the mixing chamber, which is connected within the liquid by a third tubing on which is placed a diaphragm which creates a pressure drop in the third tubing, being arranged in such a way that the stream of compressed gas conveyed by the second tubing there meets the flow of liquid conveyed by the third tubing thus generating the foam, a fourth tubing conveying the foam for mé means of application thereof on the parts to be treated,
• the value of the diameter of the diaphragm being chosen as a function of the value of the pressure applied downstream of the expansion means so that, for a given product, the foam forms inside the mixing chamber by injection of the treatment product in the compressed gas stream.

According to an advantageous embodiment, the mixing chamber is formed by two pipes forming "T", the bar of the "T" materializing the supply pipe for the compressed gas and the leg, the supply pipe for the liquid treatment product. , the diaphragm which is arranged in the supply pipe of the liquid treatment product being constituted by a washer.

According to another advantageous embodiment, a single enclosure is equipped with several sets of pipes forming the mixing chamber, these sets making it possible to simultaneously treat several rooms using foam produced using the liquid treatment product. kept under pressure in the aforementioned single enclosure.

• - la figure 1 est une vue schématique en élévation avec parties coupées montrant les parties constitutives d'un appareil de production et d'application de mousse conforme à l'invention,
• - la figure 2 montre en coupe et à plus grande échelle l'une des parties constitutives de l'appareil de la figure 1.

The invention will be understood more clearly with the aid of the additional description which follows and which is given in relation to advantageous embodiments illustrated by the drawing in which:

• FIG. 1 is a schematic elevation view with cut parts showing the constituent parts of an apparatus for producing and applying foam according to the invention,
• - Figure 2 shows in section and on a larger scale one of the constituent parts of the apparatus of Figure 1.

Proposing, therefore, to establish a device of the kind in question in accordance with the invention, we proceed as follows or in an equivalent manner.

This apparatus is made to understand an enclosure 1 comprising a filling opening 2 closed by a cover 3 and intended to contain under a determined pressure a liquid treatment product from which the foam to be prepared must be prepared, in particular on the parts of premises in the food industry to be degreased and / or disinfected.

The enclosure can be made of steel, stainless steel or any other metallic or non-resistant material, in particular the corrosive action of the liquids which it must contain.

To prepare the liquid treatment product intended to be put in the form of foam, recourse may be had to solid or liquid substances which are put in the form of alkaline, acidic or neutral solutions which can convey cleaning, degreasing, descaling, disinfecting agents, perfumes or any other product making it possible to obtain the desired result, said solutions being able to simultaneously comprise several of the functions indicated above.

• - les produits liquides alcalins sont généralement à base de solutions de bases minérales et/ou organiques,
• - les produits liquides acides et/ou halogénés, notamment iodés ou chlorés, sont généralement à base de solutions d'acides minéraux et/ou organiques, l'halogène étant amené sous toute forme permettant sa libération au moment de l'utilisation.

By way of nonlimiting example, it is indicated that:

• - alkaline liquid products are generally based on solutions of mineral and / or organic bases,
• - Acid and / or halogenated liquid products, in particular iodized or chlorinated, are generally based on solutions of mineral and / or organic acids, the halogen being brought in any form allowing its release at the time of use.

The liquid treatment products contain one or more foaming surfactants adapted to the base or to the acid chosen and necessary for the generation of the foam.

• - le lauryléthersulfate de sodium généralement avec 3 molécules d'oxyde d'éthylène fixées sur l'alcool laurique,
• - le dodécylbenzènesulfonate de sodium,
• - les associations de tensio-actifs non ioniques du type nonylphénol oxyéthyléné avec respectivement 10 et 25 molécules d'oxyde d'éthylène.

Examples of foaming products include those identified below:

• - sodium laurylethersulfate generally with 3 molecules of ethylene oxide fixed on lauric alcohol,
• - sodium dodecylbenzenesulfonate,
• - associations of nonionic surfactants of the nonylphenol oxyethylenated type with respectively 10 and 25 ethylene oxide molecules.

• - produit liquide alcalin dégraissant :
  

• - produit liquide acide iodé désinfectant :
  

As examples, two formulations of liquid treatment products have been given which have given satisfaction:

• - degreasing alkaline liquid product:
  

• - disinfectant iodized acid liquid product:
  

These liquid products can be prepared by dilution from concentrates containing the constituent substances except possibly the foaming agent which is added at the time of dilution.

They can also be prepared by dissolving the constituent substances in water in suitable proportions.

The liquid treatment product 4 is placed in the mobile enclosure 1 on rollers la and comprising a drain valve 16.

In combination with this enclosure, a pipe 5 is provided comprising pressure reducing means 6 and adaptable to a source 8 of compressed gas.

The pipe 5 forms, downstream of the means 6, first and second pipes 9 and 10 respectively equipped with non-return means, in particular with non-return valves 11 and 12, and suitable for conveying the compressed gas respectively inside from the enclosure and to a mixing chamber 13.

The tubing 9 penetrates inside the enclosure through a sealed opening 14 and preferably opens at the bottom of the enclosure within the liquid 4.

The mixing chamber 13 is connected within the liquid 4, preferably at a location near the bottom of the enclosure, by a third tube 15 on which) is placed a diaphragm 16 forming a hole 16a, this tubing entering chamber 13 through a sealed opening 15a; thanks to the diaphragm, a pressure drop is created in this tubing.

The mixing chamber is arranged in such a way that the stream of compressed gas conveyed by the second tubing there encounters the stream of treatment liquid supplied by the third tubing thus generating the foam which is conveyed by a fourth tubing 17 to means of application thereof, for example a lance 18 comprising a tap 19.

The value of the diameter d of the hole formed by the diaphragm 16 is chosen as a function of the value of the pressure p applied downstream of the expansion means 6 so that, for a given liquid treatment product, the foam is formed by injection. liquid product in the stream of compressed gas inside the mixing chamber constituted in particular by the space delimited by the pipes 10, 15 and 17 at their meeting point.

Advantageously, the mixing chamber 13 is formed by the meeting point of two tubes 20 and 21 arranged in "T" shape, as shown in FIG. 2. The tube 20 which forms the bar of the "T" is connected to the pipes 10 and 17 ; the tube 21 which forms the leg of the "T" is connected to the tube 15 by a nozzle 22; the latter comprises at its end a flange 23 by which the diaphragm 16 which may be in the form of a washer, for example made of synthetic plastic material, is applied against the end of the tube 21.

The tightening of the washer 16 between the flange 23 and the end of the tube 21 can be carried out using a nut 24 cooperating with a thread 25 formed by the tube 21 and comprising a flange 25 which, when the nut is clamped on the tube, is applied against the flange 23.

The operation of the device thus arranged is as follows.

The enclosure is filled for example three- quarters of the liquid treatment product prepared for example from a concentrate by dilution.

It is also possible to mix inside the enclosure the water and the concentrate or the constituents thereof.

The cover 3 is then closed, the pipe 5 is adapted to the source of compressed gas 8 and the enclosure is placed under the desired pressure p by acting on the expansion device 6, the tap 19 of the lance 18 being closed.

Once the pressure has been established and the expansion device maintained at the position corresponding to this pressure, it suffices to open the tap 19 so that the production of foam under the influence of the compressed gas begins; the compressed gas travels through the tube 20 in the direction of the lance 18 and the liquid 4 is injected under the effect of the pressure p into the stream of compressed gas inside the mixing chamber 13, the operation being made possible by at diaphragm 16.

Using the lance 18, the product in the form of foam can be sprayed onto the parts of the installation to be treated.

By way of an advantageous but nonlimiting example, it is indicated that good results have been obtained by applying inside the enclosure 1 a pressure p of 3.5 kg, this pressure being able to deviate more or less 10 % of this value and by giving the diameter d of the hole of the washer 16 a value equal to 3 mm; for proper operation of the assembly, the diameter d must be established with the maximum possible rigor, the liquid treatment product preferably being one of those defined above.

By changing the composition of the liquid, we may have to change the parameters p and d.

In practice, use is made of chambers with a capacity of approximately 100 liters making it possible to manufacture, for a charge, in particular of one or the other aforementioned product, a sufficient quantity of foam. to treat around 400 m- of surface.

When it comes to treating several rooms simultaneously, it is possible, to avoid having to use as many processing units, to equip a single and very large enclosure with as many sets than premises, these assemblies respectively comprising a mixing chamber and the corresponding pipes.

Following what and whatever the embodiment adopted, there is thus an apparatus for the production and application of foams intended for cleaning premises of the food industry, whose characteristics and advantages, compared to devices of the kind in question which already exist, clearly result from the above.

As goes without saying and as it already follows from the above, the invention is in no way limited to those of its modes of application and embodiments which have been more especially envisaged; on the contrary, it embraces all its variants.

Claims (3)

1. Apparatus for producing and applying foam, characterized in that it comprises, in combination: - an enclosure capable of containing, under a determined pressure, the liquid from which the foam is prepared, and - a line adaptable, by means of expansion means, to a source of compressed gas and suitable for conveying this compressed gas in parallel inside the enclosure by a first tube and to a mixing chamber by a second tubing, the mixing chamber, which is connected within the liquid by a third tubing on which is placed a diaphragm which creates a pressure drop in the third tubing, being arranged in such a way that the stream of compressed gas conveyed by the second tubing there encounters the current of liquid conveyed by the third tubing thus generating the foam, a fourth tubing conveying the foam formed to means for applying the latter to the parts to be treated, the value of the diameter of the diaphragm being chosen as a function of the value of the pressure applied downstream of the expansion means so that, for a given product, the foam forms inside the mixing chamber by injection of the treatment product in the compressed gas stream. 2. Apparatus according to claim l, characterized in that the mixing chamber is formed by two pipes forming "T", the bar of "T" materializing the supply pipe of the compressed gas and the leg, the pipe liquid treatment product, the diaphragm which is arranged in the supply tube of the liquid treatment product being constituted by a washer. 3. Apparatus according to one of claims 1 and 2, characterized in that a single enclosure is equipped with several sets of tubing forming the mixing chamber, these assemblies making it possible to simultaneously treat several premises using foam produced using the liquid treatment product maintained under pressure in the single enclosure.

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