EP1118386A1 - Improved apparatus for finely milling and/or finely suspending substances in liquids - Google Patents

Improved apparatus for finely milling and/or finely suspending substances in liquids Download PDF

Info

Publication number
EP1118386A1
EP1118386A1 EP00830031A EP00830031A EP1118386A1 EP 1118386 A1 EP1118386 A1 EP 1118386A1 EP 00830031 A EP00830031 A EP 00830031A EP 00830031 A EP00830031 A EP 00830031A EP 1118386 A1 EP1118386 A1 EP 1118386A1
Authority
EP
European Patent Office
Prior art keywords
container
finely
liquids
milling
ultrasonic
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Withdrawn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
EP00830031A
Other languages
German (de)
French (fr)
Inventor
Roberto Saponaro
Mario Ughetti
Celestino Ronchi
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.)
MIT Srl
Original Assignee
MIT Srl
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 MIT Srl filed Critical MIT Srl
Priority to EP00830031A priority Critical patent/EP1118386A1/en
Publication of EP1118386A1 publication Critical patent/EP1118386A1/en
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B02CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02CCRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C19/00Other disintegrating devices or methods
    • B02C19/18Use of auxiliary physical effects, e.g. ultrasonics, irradiation, for disintegrating
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B02CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02CCRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C17/00Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls
    • B02C17/16Mills in which a fixed container houses stirring means tumbling the charge

Definitions

  • Apparatus for suspending solids in liquids are taught in the prior art, in particular in the field of production of suspended organic and inorganic pigments.
  • These apparatus are usually discontinuously operated and, very briefly, comprise a container for containing the substances and components, in which the dissolving is done, very often in vacuum conditions, by mechanical stirring groups as well as special indented rotors set in rotation.
  • the degree of suspension influences numerous properties, such as chromatic characteristics, rheological flow characteristics, behavioural characteristics and chemical affinity in mixtures with other products; not to forget stability over a period of time and degree of gloss or matt finish.
  • the main aim of the present invention is to obviate the limitations and drawbacks in the prior art in order to obtain high-concentrate suspensions of solids in liquids, characterised by great stability and an extremely homogeneous distribution, including from the point of view of granulometry, of the solid in the liquid carrier.
  • Another main aim is to obtain a liquid/liquid dispersion which is perfectly homogenous, free of microfoam and stable over a period of time.
  • Advantages of the invention are that it does not require great use of surface-active agents, it achieves an excellent separation of solid powder aggregates and does not lead to a high wastage of mechanical energy transmitted via rotating organs (rotors) which, in known applications, create high chemical-physical stress in the suspension and resulting solution.
  • a further advantage of the invention is that the processes of grinding or milling are much quicker.
  • 1 denotes in its entirety a container which is destined to contain a fluid mass constituted by a mixture of a solid suspended in a liquid.
  • the container 1 is the shell comprising a lower refining chamber 10 and an upper chamber 11 of a ball mill 3 used in particular for refining or fine grinding of silk-screening glazes and, more in general, for the suspension of solids in liquids.
  • the lower refining chamber 10 contains the milling balls, which balls grind when moved by the mechanical rotating action of the shaft 12, which shaft 12 is provided with rotors.
  • a similar apparatus to the above-described one is constituted by the mill 3' of figure 3, in which the balls are contained in a basket 14 which is solidly constrained to a lid covering the container 1 which will contain a fluid mass constituted by a mixture of a solid in a liquid.
  • Figure 4 schematically represents a mixer the function of which is solely that of causing an already at least quite finely-ground solid to disperse without rendering the solid even more finely-ground.
  • the dispersion of the solid is achieved by a mechanical mixing action on the part of a rotor 5 which, immersed in the mass, is rapidly rotated.
  • All of the illustrated embodiments exhibit a container 1 to which lateral walls (which have an overall axial-symmetric conformation) two ultrasonic generators 2, in the form of plates, are applied at peripheral positions.
  • These ultrasonic generators 2 have the specific function of transmitting energy at ultrasonic frequency to the mass contained in the container 1.
  • the ultrasonically-emitted energy which can be modulated and regulated according to needs, exerts a direct dispersant action on the solids in the liquid, exploiting the ability of this form of energy to propagate easily in a liquid carrier.
  • the transmission of ultrasonic energy preferably in a frequency range comprised between 5 and 70 kHz, has the effect of increasing the contact surface between solid particles and the liquid, favouring wetting.
  • ultrasound which is preferably done at constant frequencies, also activates and optimizes the process of homogenization of the surface-active agents and/or dispersants, This permits production of mixtures with higher concentrations of suspended solids with smaller quantities of surface-active agents, with a consequent reduction in the formation of microfoam, which leads to suspension instability.
  • solids for example, mineral-rich, synthetic, organic and inorganic pigments, colouring earths
  • solids can be dispersed in liquids and produce a mixture characterised by a high concentration of solid and a good level of chemical-physical stability over time, leading to ease of use.
  • a Further advantage of the invention is constituted by an improvement in the chromatic quality of the products.
  • All of the described realisations employ an improved process for finely milling and/or finely dispersing solids in liquids or liquids in liquids, which is essentially characterised by the fact that energy is transmitted in the form of ultrasonic waves to the mass of solids and liquids during the milling of the former and also during the dispersion of one in the other, or of liquids in liquids.

Abstract

The improved apparatus of the invention comprises a container (1) in which a dispersion and/or a milling is performed by mechanical organs, and also comprises at least one ultrasonic generator (2) which transmits ultrasonic energy to a mass contained in the container (1).

Description

  • Apparatus for suspending solids in liquids are taught in the prior art, in particular in the field of production of suspended organic and inorganic pigments. These apparatus are usually discontinuously operated and, very briefly, comprise a container for containing the substances and components, in which the dissolving is done, very often in vacuum conditions, by mechanical stirring groups as well as special indented rotors set in rotation.
  • Also known are other apparatus (mills) which wet-mill solid components mixed with liquids.
  • For numerous production applications such as, for example, production of pigment suspensions, it is of fundamental importance that stable suspensions be produced, with high solid suspension content.
  • The degree of suspension influences numerous properties, such as chromatic characteristics, rheological flow characteristics, behavioural characteristics and chemical affinity in mixtures with other products; not to forget stability over a period of time and degree of gloss or matt finish.
  • In relation to the above-mentioned characteristics, known realisations exhibit several limitations which appear to be constitutional or organic, in the sense that the results obtainable are not improvable, even by considerably increasing treatment times (for example, in the case of mills, greatly increasing milling time).
  • A similar limitation exists in relation to the mass of solid which can be dispersed sufficiently stably in a determined mass of liquid.
  • The main aim of the present invention is to obviate the limitations and drawbacks in the prior art in order to obtain high-concentrate suspensions of solids in liquids, characterised by great stability and an extremely homogeneous distribution, including from the point of view of granulometry, of the solid in the liquid carrier. Another main aim is to obtain a liquid/liquid dispersion which is perfectly homogenous, free of microfoam and stable over a period of time.
  • Advantages of the invention are that it does not require great use of surface-active agents, it achieves an excellent separation of solid powder aggregates and does not lead to a high wastage of mechanical energy transmitted via rotating organs (rotors) which, in known applications, create high chemical-physical stress in the suspension and resulting solution.
  • A further advantage of the invention is that the processes of grinding or milling are much quicker.
  • These aims and advantages and others besides are all attained by the invention as it is characterised in the appended claims.
  • Further characteristics and advantages of the present invention will better emerge from the detailed description that follows of some preferred but non-exclusive embodiments of the invention, illustrated purely by way of nonlimiting examples in the accompanying figures of the drawings, in which:
  • figure 1 shows a schematic section made according to line I-I of figure 2, relating to a first embodiment of the invention;
  • figure 2 is a schematic lateral view from the left of figure 1;
  • figure 3 is a schematic median section according to a vertical plane of a second embodiment of the invention;
  • figure 4 is a schematic median section according to a vertical plane of a further embodiment of the invention.
  • With reference to the figures of the drawings, 1 denotes in its entirety a container which is destined to contain a fluid mass constituted by a mixture of a solid suspended in a liquid.
  • In the embodiment shown in figures 1 and 2, the container 1 is the shell comprising a lower refining chamber 10 and an upper chamber 11 of a ball mill 3 used in particular for refining or fine grinding of silk-screening glazes and, more in general, for the suspension of solids in liquids.
  • The lower refining chamber 10 contains the milling balls, which balls grind when moved by the mechanical rotating action of the shaft 12, which shaft 12 is provided with rotors.
  • A similar apparatus to the above-described one is constituted by the mill 3' of figure 3, in which the balls are contained in a basket 14 which is solidly constrained to a lid covering the container 1 which will contain a fluid mass constituted by a mixture of a solid in a liquid.
  • Figure 4 schematically represents a mixer the function of which is solely that of causing an already at least quite finely-ground solid to disperse without rendering the solid even more finely-ground. The dispersion of the solid is achieved by a mechanical mixing action on the part of a rotor 5 which, immersed in the mass, is rapidly rotated.
  • All of the illustrated embodiments exhibit a container 1 to which lateral walls (which have an overall axial-symmetric conformation) two ultrasonic generators 2, in the form of plates, are applied at peripheral positions.
  • Other embodiments could involve a different number of ultrasonic generators 2.
  • These ultrasonic generators 2 have the specific function of transmitting energy at ultrasonic frequency to the mass contained in the container 1.
  • The ultrasonically-emitted energy, which can be modulated and regulated according to needs, exerts a direct dispersant action on the solids in the liquid, exploiting the ability of this form of energy to propagate easily in a liquid carrier.
  • The transmission of ultrasonic energy, preferably in a frequency range comprised between 5 and 70 kHz, has the effect of increasing the contact surface between solid particles and the liquid, favouring wetting.
  • In addition to the above, a process of cavitation occurs, which enables efficient expulsion of the air produced during the mechanical diffusion of the solid in the liquid.
  • This condition, together with the vacuum action created by the machine and a careful control of the temperature, creates optimal conditions for deagglomeration of clumps and micronisation of the solid particles. This leads to a very high percentage of suspended solids, a level which is certainly not obtainable using traditional systems which do not use ultrasonic techniques, without any ensuing problems connected with rheological high viscosity factors, which would render the resulting suspensions unusable.
  • Furthermore, in comparison to the prior art, the processes of breaking-up and micronisation are significantly accelerated.
  • The use of ultrasound, which is preferably done at constant frequencies, also activates and optimizes the process of homogenization of the surface-active agents and/or dispersants, This permits production of mixtures with higher concentrations of suspended solids with smaller quantities of surface-active agents, with a consequent reduction in the formation of microfoam, which leads to suspension instability.
  • Thus solids (for example, mineral-rich, synthetic, organic and inorganic pigments, colouring earths) can be dispersed in liquids and produce a mixture characterised by a high concentration of solid and a good level of chemical-physical stability over time, leading to ease of use.
  • A Further advantage of the invention is constituted by an improvement in the chromatic quality of the products.
  • All of the described realisations employ an improved process for finely milling and/or finely dispersing solids in liquids or liquids in liquids, which is essentially characterised by the fact that energy is transmitted in the form of ultrasonic waves to the mass of solids and liquids during the milling of the former and also during the dispersion of one in the other, or of liquids in liquids.

Claims (9)

  1. An improved apparatus for finely milling and/or finely suspending substances in liquids, comprising a container (1) in which milling is performed and/or dispersion is performed by mechanical organs, characterised in that it comprises at least one ultrasonic generator (2) for transmitting ultrasonic waves to a mass contained in the container (1).
  2. The apparatus of claim 1, characterised in that the at least one ultrasonic generator (2) is associated to a wall of the container (1).
  3. The apparatus of claim 2, characterised in that it comprises at least two of said at least one ultrasonic generator (2), associated to walls of the container (1) at peripheral positions.
  4. The apparatus of claim 3, characterised in that at least the walls of the container (1) to which the ultrasonic generators (2) are peripherally associated have an axial-symmetric conformation.
  5. The apparatus of claim 4, characterised in that the container (1) comprises at least one chamber of a ball-mill (3, 3') containing milling balls.
  6. The apparatus of claim 4, characterised in that the container (1) comprises at least one chamber of a mixer (4) internally of which at least one rotor (5) operates.
  7. The apparatus of claim 5 or 6, characterised in that the container (1) is provided with a lid which guarantees sealed closure of the container (1) during operation thereof in depression.
  8. The apparatus of claim 7, characterised in that the ultrasonic generators (2) can be adjusted to enable regulation and modulation of energy emitted.
  9. An improved apparatus for finely milling and/or finely suspending substances in liquids, characterised in that energy is transmitted in ultrasonic waves to a mass of solids and liquids during milling and/or during dispersion of the substances in liquids.
EP00830031A 2000-01-20 2000-01-20 Improved apparatus for finely milling and/or finely suspending substances in liquids Withdrawn EP1118386A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP00830031A EP1118386A1 (en) 2000-01-20 2000-01-20 Improved apparatus for finely milling and/or finely suspending substances in liquids

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP00830031A EP1118386A1 (en) 2000-01-20 2000-01-20 Improved apparatus for finely milling and/or finely suspending substances in liquids

Publications (1)

Publication Number Publication Date
EP1118386A1 true EP1118386A1 (en) 2001-07-25

Family

ID=8175137

Family Applications (1)

Application Number Title Priority Date Filing Date
EP00830031A Withdrawn EP1118386A1 (en) 2000-01-20 2000-01-20 Improved apparatus for finely milling and/or finely suspending substances in liquids

Country Status (1)

Country Link
EP (1) EP1118386A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103521763A (en) * 2013-11-01 2014-01-22 赣州中瑞材料科技有限公司 Process for preparing superfine tungsten-base alloy powder by microwave-assisted ball-milling
CN103785511A (en) * 2014-03-04 2014-05-14 湖南大学 Microwave and ultrasound combined assisted ball-milling device and process for preparing high-performance nanopowder
CN109465462A (en) * 2018-12-17 2019-03-15 河源富马硬质合金股份有限公司 A kind of new ball milling method prepares hard alloy
CN114029129A (en) * 2021-11-13 2022-02-11 淄博大力矿山机械有限公司 Building materials cornmill

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1254001B (en) * 1964-04-07 1967-11-09 Draiswerke Ges Mit Beschraenkt Agitator mill
DE1507528B1 (en) * 1966-12-06 1970-09-24 Fryma Masch Ag Device for processing and preparing flowable products
EP0065188A2 (en) * 1981-05-14 1982-11-24 BASF Aktiengesellschaft Separating device for separating grinding bodies and a ground suspension in a wet-grinding machine
US4964576A (en) * 1988-04-04 1990-10-23 Datta Rabinder S Method and apparatus for mineral matter separation
US5279463A (en) * 1992-08-26 1994-01-18 Holl Richard A Methods and apparatus for treating materials in liquids
EP0686428A1 (en) * 1994-06-10 1995-12-13 Eastman Kodak Company Micro media mill and method of its use

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1254001B (en) * 1964-04-07 1967-11-09 Draiswerke Ges Mit Beschraenkt Agitator mill
DE1507528B1 (en) * 1966-12-06 1970-09-24 Fryma Masch Ag Device for processing and preparing flowable products
EP0065188A2 (en) * 1981-05-14 1982-11-24 BASF Aktiengesellschaft Separating device for separating grinding bodies and a ground suspension in a wet-grinding machine
US4964576A (en) * 1988-04-04 1990-10-23 Datta Rabinder S Method and apparatus for mineral matter separation
US5279463A (en) * 1992-08-26 1994-01-18 Holl Richard A Methods and apparatus for treating materials in liquids
EP0686428A1 (en) * 1994-06-10 1995-12-13 Eastman Kodak Company Micro media mill and method of its use

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103521763A (en) * 2013-11-01 2014-01-22 赣州中瑞材料科技有限公司 Process for preparing superfine tungsten-base alloy powder by microwave-assisted ball-milling
CN103785511A (en) * 2014-03-04 2014-05-14 湖南大学 Microwave and ultrasound combined assisted ball-milling device and process for preparing high-performance nanopowder
CN103785511B (en) * 2014-03-04 2016-02-24 湖南大学 A kind of microwave ultrasound associating auxiliary ball mill apparatus and technique preparing high-performance nano powder
CN109465462A (en) * 2018-12-17 2019-03-15 河源富马硬质合金股份有限公司 A kind of new ball milling method prepares hard alloy
CN114029129A (en) * 2021-11-13 2022-02-11 淄博大力矿山机械有限公司 Building materials cornmill

Similar Documents

Publication Publication Date Title
US3638917A (en) Method and apparatus for continuously dispersing materials
US3756570A (en) Apparatus for continuous dispersion and homogenization of predominantly viscous substances
CZ290010B6 (en) Mobile apparatus for the production of water-based liquid paints from pulverulent constituents and water and process for producing water-based liquid paints
CN208340565U (en) A kind of solid-liquid mixer
JP4174000B2 (en) Distributed device
US3944144A (en) Method and apparatus for dispersing suspensions
JPH11501573A (en) Dispersing apparatus and dispersing method
EP1118386A1 (en) Improved apparatus for finely milling and/or finely suspending substances in liquids
CN105080376A (en) Suspension and colloid preparation method, and apparatus system and application thereof
JPS57127431A (en) Vacuum mixing and defoaming machine
JP2000237563A (en) Continuous dispersion device
KR101196332B1 (en) Homogenizing mixer
JP2002528258A (en) Dispersion equipment
JPH06312124A (en) Fluid mixing dispersion machine
JP2010005540A (en) Wet dispersion or grinding method, and wet disperser used for this method
CN1380365A (en) Paint production method and equipment
CN209714855U (en) Organic-silicon-modified aqueous surface-treating agent agitation grinding device
CN207507285U (en) A kind of high speed dispersor
CN213669469U (en) Cosmetic cream mixed colloid grinder
KR20200042833A (en) Agitator mill
CN218393926U (en) Hollow silicon nitride ceramic ball grinding device
CN109317003A (en) A kind of coating material production agitating device
FI91602B (en) Process for dispersing pigment or similar finely divided solid particles in a medium
JPH08173826A (en) Wet dispersing pulverizer and method thereof
CN208493919U (en) A kind of coating material agitator of layering stirring

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

17P Request for examination filed

Effective date: 20011105

AKX Designation fees paid

Free format text: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

17Q First examination report despatched

Effective date: 20031027

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20040507