GB2076672A - Making foam - Google Patents

Making foam Download PDF

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Publication number
GB2076672A
GB2076672A GB8005391A GB8005391A GB2076672A GB 2076672 A GB2076672 A GB 2076672A GB 8005391 A GB8005391 A GB 8005391A GB 8005391 A GB8005391 A GB 8005391A GB 2076672 A GB2076672 A GB 2076672A
Authority
GB
United Kingdom
Prior art keywords
venturi
liquor
foam
tube
air
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB8005391A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Unilever PLC
Original Assignee
Unilever PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Unilever PLC filed Critical Unilever PLC
Priority to GB8005391A priority Critical patent/GB2076672A/en
Publication of GB2076672A publication Critical patent/GB2076672A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • AHUMAN NECESSITIES
    • A47FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47LDOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
    • A47L11/00Machines for cleaning floors, carpets, furniture, walls, or wall coverings
    • A47L11/40Parts or details of machines not provided for in groups A47L11/02 - A47L11/38, or not restricted to one of these groups, e.g. handles, arrangements of switches, skirts, buffers, levers
    • A47L11/408Means for supplying cleaning or surface treating agents
    • A47L11/4083Liquid supply reservoirs; Preparation of the agents, e.g. mixing devices
    • AHUMAN NECESSITIES
    • A47FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47LDOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
    • A47L11/00Machines for cleaning floors, carpets, furniture, walls, or wall coverings
    • A47L11/32Carpet-sweepers
    • A47L11/325Shampoo devices for carpet-sweepers
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F25/00Flow mixers; Mixers for falling materials, e.g. solid particles
    • B01F25/30Injector mixers
    • B01F25/31Injector mixers in conduits or tubes through which the main component flows
    • B01F25/311Injector mixers in conduits or tubes through which the main component flows for mixing more than two components; Devices specially adapted for generating foam
    • B01F25/3111Devices specially adapted for generating foam, e.g. air foam
    • B01F25/31112Devices specially adapted for generating foam, e.g. air foam with additional mixing means other than injector mixers, e.g. screen or baffles
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F25/00Flow mixers; Mixers for falling materials, e.g. solid particles
    • B01F25/30Injector mixers
    • B01F25/31Injector mixers in conduits or tubes through which the main component flows
    • B01F25/312Injector mixers in conduits or tubes through which the main component flows with Venturi elements; Details thereof
    • B01F25/3121Injector mixers in conduits or tubes through which the main component flows with Venturi elements; Details thereof with additional mixing means other than injector mixers, e.g. screens, baffles or rotating elements
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05BSPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B7/00Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
    • B05B7/0018Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas with devices for making foam
    • B05B7/005Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas with devices for making foam wherein ambient air is aspirated by a liquid flow
    • B05B7/0056Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas with devices for making foam wherein ambient air is aspirated by a liquid flow with disturbing means promoting mixing, e.g. balls, crowns

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Nozzles (AREA)

Abstract

In the production of foam a surfactant-containing liquor is passed through a swirling device 17 in a high pressure nozzle 19 and through an injector tube 16 into a venturi 22 where it causes air to be drawn into the apparatus. The air/liquor mixture then passes along a mixing tube 28 to the foam outlet. By specific selection of dimensions of the various components of the apparatus, a foam with an air to liquor ratio of from 9:1 to 26:1 can be produced from a surfactant-containing liquor supply at 600 to 2,200 p.s.i. The foam is used for cleaning hard surfaces particularly in food processing sites. <IMAGE>

Description

SPECIFICATION Foam producing apparatus This invention relates to a foam producing apparatus, in particular, but not exclusively to a foam producing apparatus for the power cleaning of hard surfaces in industrial food processing sites, for example, of walls, floors and operating equipment.
Foam producing apparatus are known in which a detergent containing liquid is mixed with air to produce a foam which is discharged from the apparatus under pressure. It is desirable for the apparatus to produce a foam containing little or no free liquid, and to this end it is desirable to use an air to liquid ratio in excess of about 5:1. Known foam producing apparatus to date either fail to produce a foam with an air to liquor ratio in excess of 5 :1, or do so in a manner which generates a back pressure in the air inlet of the apparatus so that it becomes necessary to use a device for producing compressed air for use with the apparatus.
It is an object of the invention to provide a foam producing apparatus which produces a foam with a high air to liquor ratio while creating little or no back pressure in the air supply.
Thus, according to the invention there is provided an apparatus for producing foam from a surfactant-containing liquor by mixing the liquor with air, said apparatus comprising (i) a venturi; (ii) liquor inlet means upstream of said venturi, said inlet means including means for subjecting a swirling motion to said liquor before it enters the venturi; (iii) air inlet means upstream of said venturi; (iv) a mixing tube downstream of said venturi and in communication therewith; and (v) a foam outlet at the down stream end of said mixing tube.
The apparatus will normally be used with a device for producing a surfactant-containing liquor at a pressure of 500 to 2,500 p.s.i. and at a flow rate between 5 and 25 litres/minute. Preferably, the ratio of the volume of the mixing tube to the volume of the venturi throat is in excess of 10:1. Advantageously, the diameter of the mixing tube is less than the diameter of the venturi throat.
Ideally, the liquor inlet means discharges the liquor into the venturi downstream of the air inlet means. This can be achieved when the liquor inlet means includes an injection tube opening directly into the venturi.
The air inlet means may be constituted by one or more air inlet tubes or by air inlet apertures opening into the apparatus. A device may also be included to control the quantity of air entering the apparatus, such as an adjustable valve or a perforated cup.
The invention will now be described, purely by way of example, with reference to an embodiment thereof shown in the accompanying drawings in which Figure 1 is a longitudinal cross section of the rear end of a foam producing apparatus according to the invention; and Figure 2 is a longitudinal cross section of the front end of the same apparatus.
The apparatus shown in the drawings comprises a cylindrical tube 10 towards the rear end of which there is provided a radially extending air inlet tube 11. Each end of the tube 10 is closed with the exception of an axial boring 13 at the front end and an axial boring 14 at the rear end, the latter consisting of a relatively wide portion immediately at the rear of the tube 10 and a relatively narrow portion to the front thereof defined by an injection tube 16 which extends into the hollow space of the tube 10 beyond the air inlet 11. In the relatively wide portion of the axial boring 14, there is inserted a swirler and a nozzle 19, the annular space between these components and the wall of the boring 14 being sealed by an O-ring 20. The diameter of the nozzle 19 is less than that of the injection tube 1 6.
Beyond the air inlet 11 and the injector tube 16 there is positioned a venturi 22 defined by an inwardly conically tapering wall 23, a cylindrical wall 25 and an outwardly conically tapering wall 26.
The diameter of the venturi throat defined by the cylindrical wall 25 is greater than the diameter of the injector tube 16. Substantially immediately beyond the venturi 22 is a mixing tube 28 which is concentric with the tube 10. The rear end of the mixing tube is secured to the tube 10 by an inwardly conically tapering wall 29 or by a sleeve (not shown) fitted around the mixing tube 28. The volume between the outwardly conically tapering wall 26 and the mixing tube tapering wall 29 is small so that expansion of the foam before entering the mixing tube is kept to a minimum. The mixing tube 28 passes through the boring 13 at the front end of the tube 10, and projects therebeyond. The front end of the mixing tube 28 is provided with an end cap 3Q.
The various components of the apparatus can be integral with the tube 10 or may all be formed by separate parts secured together by conventional engineering methods, or by any combination thereof.
The apparatus described operates as follows. A mixture of water and a surfactant and/or other cleaning materials, enters the apparatus under pressure as indicated by the arrow 31. This liquid passes through the swirler 17 where a rotational component of motion is added to its axial component of motion. The swirling liquid now passes through the nozzle 19 into the injector tube 16. The injector tube 16 is of such a length that the jet of swirling liquid emanating therefrom is substantially cylindrical, i.e. it has very little outward divergence.
As the liquid jet passes through the venturi 22, air becomes entrained therein, creating a negative pressure resulting in the sucking of air into the apparatus through the air inlet 11 as shown by the arrow 27. The mixture of air and swirling liquid now enters the mixing tube 28. The small divergence of the jet of liquid passing through the venturi 22 means that very little liquid strikes the surface of the inwardly conically tapering wall 29, so that very little back pressure is generated.
In the mixing tube 28, the air and liquid become thoroughly mixed into a foam. The end cap 30 at the front end of the mixing tube 28 has an axial bore 31 therethrough having a rectangular or elliptical cross section and a cross-sectional area approximately the same as that of the mixing tube 28 so that very little back pressure is generated at this point but sufficiently different to spread the foam jet as it exits the apparatus as shown by the arrow 32.
The performance of the apparatus in practice depends, to a large extent, on the dimensions and in particular on the relative dimensions, of the components of the apparatus. For example the mixing tube 28 must have a volume which is in excess of ten times the volume of the throat portion of the venturi as defined by the cylindrical wall 25. The diameter of the mixing tube 28 must be less than the diameter of the throat portion of the venturi.Suitable apparatus according to the invention have the following dimensions and are operated in accordance with the following parameters: Nozzle diameter 1.3 to 1.7 mm Length of injector tube 75.0 mm Length of venturi throat 17.0 mm Diameter of venturi throat 17.0 mm Length of mixing tube 65.0 mm Diameter of mixing tube (28) 10.0 to 13.0 mm Radial dimensions of end cap boring (31) 20.0 mm x 6.0 mm Liquid pressure 600 to 2,000 psi Liquid composition 0.2 to 2.0% by weight surfactant.
0.2 to 2.0% by weight alkali balance water Temperature of liquid 5 to 900C Air to liquor ratio of foam produced 9:1 to 26:1 Liquid consumption rate of an apparatus 10 to 14 litres/minute Foam residence time 5 to 20 minutes depending on air: liquor ratio and surface roughness The air to liquor ratio of the foam produced can be altered by varying (a) the nozzle diameter, (b) the air inlet diameter, (c) the venturi throat diameter, (d) the mixing tube diameter, (e) the injector tube diameter and/or (f) the distance between the nozzle and the venturi throat.

Claims (6)

1. An apparatus for producing foam from a surfactant-containing liquor by mixing the liquor with air, said apparatus comprising: (i) a venturi; (ii) liquor inlet means upstream of said venturi, said inlet means including means for subjecting a swirling motion to said liquor before it enters the venturi; (iii) air inlet means upstream of said venturi; (iv) a mixing tube downstream of said venturi and in communication therewith; and (v) a foam outlet at the downstream end of said mixing tube.
2. An apparatus as claimed in Claim 1 , wherein the ratio of the volume of the mixing tube to the volume of the venturi throat is in excess of 10:1.
3. An apparatus as claimed in Claim 1 or 2, wherein the liquor inlet means includes a high pressure nozzle and an injector tube.
4. An apparatus as claimed in Claim 3 wherein the diameter of the mixing tube is less than the diameter of the venturi throat and the diameter of the venturi throat is greater than the diameter of the high pressure nozzle and of the injector tube.
5. An apparatus as claimed in any one of Claims 1 to 4, wherein the liquor inlet means discharges the liquor into the venturi downstream of the air inlet means.
6. An apparatus substantially as hereinbefore described, with reference to, and as illustrated in, the accompanying drawings.
GB8005391A 1980-02-18 1980-02-18 Making foam Withdrawn GB2076672A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB8005391A GB2076672A (en) 1980-02-18 1980-02-18 Making foam

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB8005391A GB2076672A (en) 1980-02-18 1980-02-18 Making foam

Publications (1)

Publication Number Publication Date
GB2076672A true GB2076672A (en) 1981-12-09

Family

ID=10511454

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8005391A Withdrawn GB2076672A (en) 1980-02-18 1980-02-18 Making foam

Country Status (1)

Country Link
GB (1) GB2076672A (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2530967A1 (en) * 1982-07-28 1984-02-03 Vallet Jacques Device for producing an emulsion.
EP0145227A1 (en) * 1983-12-13 1985-06-19 Halliburton Company Method and apparatus for foam generation
US4780243A (en) * 1986-05-19 1988-10-25 Halliburton Company Dry sand foam generator
WO1990005583A1 (en) * 1988-11-22 1990-05-31 Dunne Miller Weston Limited Liquid-gas mixing device
WO2001005493A1 (en) * 1999-07-21 2001-01-25 Universite De Bourgogne Method for making emulsions and implementing device
EP2540387A4 (en) * 2010-02-23 2016-01-27 Asahi Organic Chem Ind In-line fluid mixing device
CN110614043A (en) * 2019-09-25 2019-12-27 芜湖美的厨卫电器制造有限公司 Micro-nano bubble liquid generating device and water outlet equipment

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2530967A1 (en) * 1982-07-28 1984-02-03 Vallet Jacques Device for producing an emulsion.
EP0145227A1 (en) * 1983-12-13 1985-06-19 Halliburton Company Method and apparatus for foam generation
US4780243A (en) * 1986-05-19 1988-10-25 Halliburton Company Dry sand foam generator
WO1990005583A1 (en) * 1988-11-22 1990-05-31 Dunne Miller Weston Limited Liquid-gas mixing device
WO2001005493A1 (en) * 1999-07-21 2001-01-25 Universite De Bourgogne Method for making emulsions and implementing device
FR2796568A1 (en) * 1999-07-21 2001-01-26 Amora Maille PROCESS FOR PRODUCING EMULSIONS AND DEVICE THEREOF
EP2540387A4 (en) * 2010-02-23 2016-01-27 Asahi Organic Chem Ind In-line fluid mixing device
CN110614043A (en) * 2019-09-25 2019-12-27 芜湖美的厨卫电器制造有限公司 Micro-nano bubble liquid generating device and water outlet equipment
CN110614043B (en) * 2019-09-25 2022-05-06 芜湖美的厨卫电器制造有限公司 Micro-nano bubble liquid generating device and water outlet equipment

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WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)