An apparatus for mixing and delivering liquids in the form of a compact foam

Abstract

 The apparatus comprises a tank 1 for a first liquid, or solvent, generally water, connected upstream to a continuous source of supply, and downstream, via a first conduit 3, to a pump P whose output is in turn connected, via a second conduit 5, to a mixing device 6 for forming foam, supplied by a third pipe 7 connected to a source of compressed air C. Upstream or downstream of the said pump P a fourth conduit 9 supplies, via a regulator-doser 10, a second liquid, or solute, coming from a corresponding container 8.

Description

[0001] The invention relates to an apparatus for mixing and delivering liquids in the form of a compact foam, the application field for which is to be found in large areas where, with a certain frequency, it is necessary to thoroughly clean vast surfaces that have been sullied with residues of animal nature (fats in particular) such as, for example, slaughter houses and factories where salami, cheeses and foodstuffs in general, and the like, are produced.

[0002] In such places, the cleaning operation consists in contemporaneously washing down the flooring and the walls, both of which are generally faced with tiles, marble or steel etcetera.

[0003] Because of the extension of the said surfaces, the washing operation can only be effected with equipments of an industrial nature, amongst which abound conventional hoses supplied with water at a high pressure and temperature, which operate prevalently through a mechanical action of the water with results that are reasonably good (cleaning in the order of 80 - 85%) though with very high loss and water heating costs.

[0004] Equipments have, therefore, been designed to deliver foam from a solvent-liquid detergent mixture which, in quite a compact form, can easily be applied to the walls and be left there for a given period of time sufficient to exercise an extremely efficient cleansing action, after which it can be removed through a normal rinsing operation.

[0005] Such equipments are constituted by a vessel that is filled with a predetermined quantity of water A, to which the operator adds each time, the right percentage of liquid detergent B with which to obtain the desired mixture. The operator then mixes A and B, seals the container hermetically and connects it to a source of compressed air. The water-detergent mixture passes from the said container into a mixing device to which, moreover, the aforementioned source of pressurized air is connected, and thus the incoming liquid mixture is "transformed" into foam, this being due to the high percentage of air and to the surface tension characteristics of the liquid B.

[0006] With the said equipments there is, however, a large scale problem because of the limited volume of the pressure vessel both for fixed installations and, above all, as can be seen in practice, for a mobile plant. In the latter case, the vessel is emptied in an extremely short span of time (in the order of a few minutes), with the result that the operator has to constantly repeat the aforementioned operations of "discharging" the pressure from the container, filling it with the liquid A, adding the liquid B, mixing one with the other and sealing the container, besides running the risk of coming into contact with the liquid detergent that is highly toxic.

[0007] The object of the invention consists, therefore, in overcoming the above mentioned difficulties by making available an apparatus that allows a first liquid solvent and at least a second liquid detergent, or solute, to be mixed continuously in predetermined quantities, and the said mixture to be subsequently delivered in the form of a compact foam, without it being necessary to have to continually intervene manually in the said mixing operation, without high volume pressure vessels being used, and without interruptions in the delivery of the foam; all this with an extremely simple apparatus, the cost of which is low in comparison to the results obtainable therewith.

[0008] A further object of the invention consists in constructing the said apparatus in such a way that without having to alter the capacity of the vessels - and of the liquid solvent vessel in particular - it can be utilized both for fixed applications and for mobile employment.

[0009] These and other objects too are all attained with the apparatus according to the invention, characteristics of which are that it comprises: a first tank for a first liquid, or solvent, A, connected, via a first conduit, to a pump whose output is in turn connected, via a second conduit, to a mixing-injecting device for forming foam, supplied by a third pipe connected to a source of compressed air; at least one second container for a second liquid, or solute, B, provided with a fourth conduit that runs, via a regulator -doser, into the conduit upstream or downstream of the said pump.

[0010] Further characteristics and advantages of the invention will become more obvious from the detailed description that follows, illustrated purely as an unlimited example, on the accompanying drawing, in which:

- Figure 1 is a diagrammatic representation of the apparatus forming the subject of the invention.

[0011] With reference to the above mentioned figure, the apparatus, which in its mobile form of embodiment is mounted on a non illustrated carriage in order to allow it to be moved into the place of use, comprises a first tank 1 that contains the solvent (or water) A that is connected directly, via a flexible pipe 2, to a continuous source of supply and, downstream is connected to a first conduit 3, fitted with a non return valve 4, connected to pumping means P (in the case under consideration, a centrifugal pump), the delivery of which goes, via a second conduit 5, to a mixing-injecting device 6 of a known type, utilized for forming the foam together with a source of compressed air coming from a compressor C via a third pipe 7.

[0012] -At 8 there is a second tank that contains a liquid detergent (or solute) B, which is sent, via a fourth conduit 9, into the solvent A upstream of the pump P. The said fourth conduit 9 is provided with means for dosing the liquid B and for cutting off the flow thereof, shown globally at 10, in the case under consideration constituted by a doser pump of, for example, the diaphragm type.

[0013] The operation of the apparatus is extremely simple since all that has to be done is To actuate, at the same time, the pump P and the means 10 in order to cause the liquid A to be drawn from the tank 1 and the liquid B from the tank 8 in the required quantity determined by the said regulating means 10 (obviously in proportion to the quantity drawn of the solvent A in such a way as to define the exact percentage of the mixture to be "transformed" into foam).

[0014] The two liquids A and B, partially mixed at the inlet to the pump P undergo, through the action of the impeller of the latter, complete and thorough mixing in such a way that when entering the mixing-injecting device 6, the solution is in an ideal condition to give rise, together with the compressed air coming from the conduit 7, to a compact foam that is deposited on to the walls to be cleaned and stays there all the time needed for a cleansing action.

[0015] With the apparatus in question it is, therefore, possible to have a ccnstant delivery of foam because of the liquid A being supplied continuously through the pipe 2 and, likewise, because of the continuous supply and mixing of the liquid B which can be varied, all the time, percentage wise within required values such as to give rise to the formation of foam having more or less variable physical and attacking characteristics, without the need to resort to pressure tanks and the intermittent operation consequential thereto, and without manual assistance, especially as regards the liquid B.

[0016] Obviously the various components, in view of the toxicity of the solute, shall be constructed out of suitable material (stainless steel), while in place of the doser pump 10 the use may be envisaged of an on-off valve 10' and of a doser valve 10". In general, the tank 1 shall be provided with a float device so as to maintain constant the level of liquid in the inside thereof.

[0017] The apparatus can be utilized as a mobile plant, as illustrated, or as a fixed installation, in which case it is envisaged that a number of mixing devices 6 be installed in the various areas to be cleaned.

[0018] In its practical form of embodiment, the invention may also adopt forms that differ from the one illustrated and, in particular, numerous modifications of a practical nature may be made without there being any deviation from the framework of protection afforded to the invention.

Claims

1. An apparatus for mixing and delivering liquids in the form of a compact foam, characterized in that it comprises: a first tank 1 for a first liquid, or solvent, A, connected, via a first conduit 3, to a pump P whose output is in turn connected, via a second conduit 5, to a mixing-injecting device 6 for forming foam, supplied by a third pipe 7 connected to a source of compressed air C; and at least one second container 8 for a second liquid, or solute, B, provided with a fourth conduit 9 that runs, via a regulator -doser 10, into the said conduit upstream or downstream of the said pump.

2. An apparatus according to Claim 1, wherein the said first tank 1 is connected, upstream, to a source of supply of the said first liquid, and downstream, to the said first conduit 3.

3. An apparatus according to Claim 1, wherein the said regulator-doser 10 is constituted by a doser pump.

Drawing