AU675288B2 - Process for the production of fine granules - Google Patents
Process for the production of fine granules Download PDFInfo
- Publication number
- AU675288B2 AU675288B2 AU59223/94A AU5922394A AU675288B2 AU 675288 B2 AU675288 B2 AU 675288B2 AU 59223/94 A AU59223/94 A AU 59223/94A AU 5922394 A AU5922394 A AU 5922394A AU 675288 B2 AU675288 B2 AU 675288B2
- Authority
- AU
- Australia
- Prior art keywords
- solvent
- product melt
- process according
- melt
- speed mixer
- 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.)
- Ceased
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2/00—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic
- B01J2/10—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic in stationary drums or troughs, provided with kneading or mixing appliances
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2/00—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic
- B01J2/003—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic followed by coating of the granules
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Glanulating (AREA)
- Medicinal Preparation (AREA)
- Drying Of Solid Materials (AREA)
Description
Our Ref: 499524 P/00/011 Regulation 3:2
AUSTRALIA
Patents Act 1990
ORIGINAL
COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): Ciba-Geigy AG Klybeckstrasse 141 CH-4002 BASLE
SWITZERLAND
DAVIES COLLISON CAVE Patent Trade Mark Attorneys Level 10, 10 Barrack Street SYDNEY NSW 2000 Address for Service: Invention Title: Process for the production of fine granules The following statement is a full description of this invention, including the best method of performing it known to me:- 5020 A7-19521/A Process for the production of fine granules The invention relates to a process for the production of fine granules in accordance with the preamble of patent claim 1.
Various processes for the production of granules are known. US-A-4 578 021 describes a granulating process in which a supercooled melt provided with seed crystals is pressed S. through openings in a perforated hollow roller in which a rotating pressure roller is provided. The pressed-out drops fall onto a cooling belt and can there solidify or crystallise out. The granules that can be obtained by that process are of a relatively large size which is determined by the dimensions of the openings in the hollow roller.
In another known process for the production of fine granules, dry powder, powder mixtures or also centrifuged and then washed crystallisate is/are mixed with product melt in a high-speed mixer. The granules formed by crystallisation during that operation are discharged from the high-speed mixer and then dried and/or cooled in a drier, for example a moving bed drier or a fluidised bed drier. Although that process is able to yield fine, low-dust granules, the granules are in many cases not abrasion-resistant. In addition, the application of the process is limited. In particular, in many cases it has hitherto been impossible to use that process to granulate products having high melting points or having high viscosities of the product melt, since the product melt does not adequately wet the powder, or the powder mixture or the crystallisate, in the high-speed mixer. Owing to the long crystallisation time, the product melt often does not crystallise completely, which leads to incrustation of the mixer and to lumps which may clog the pipes.
The problem of the invention is accordingly to provide a process for the production of fine granules by means of which substantially dust-free, stable, completely crystallised granules or agglomerates can be produced. It is also to be possible to use the proc'.; in the case of products having high melting points and/or having high viscosities of the product melt. The process is to permit products of mixtures of any number of components to be granulated in small paxticle sizes.
~I -2- Those problems are solved according to the invention by a process that comprises the process steps listed in the second part of patent claim 1. In the process according to the invention for the production of fine granules a product melt from a melt tank is supercooled and then metered or sprayed into a high-speed mixer and there brought into contact with dry powder, powder mixtures or also with centrifuged and then washed crystallisate from a silo. During that operation, granules are formed by crystallisation, which are discharged from the high-speed mixer, subsequently dried and/or cooled in a drier, for example a moving bed drier or a fluidised bed drier, and then removed from the drier.
Prior to cooling, the product melt is mixed with a solvent, as a result of which its viscosity is greatly reduced and its wetting capacity in respect of the powder, the crystallisate or the powder mixtures is substantially increased. The product melt/solvent mixture is then S supercooled preferably to within the metastable range of the solubility curve so that rapid crystallisation commences in the high-speed mixer. During that operation, the temperature of the product melt/solvent mixture is so regulated that the mixture does not boil at the spray outlet in the high-speed mixer. The viscosity of the product melt is thus markedly reduced and the wetting capacity of the product melt is greatly improved. Crystallisation takes place very rapidly in the high-speed mixer and incrustation and lumps are avoided.
The dependent patent claims relate to preferred process variants.
The process according to the invention is explained in more detail hereinafter with refer° ence to the single Figure which shows diagrammatically a granulation system for implem- S enting the process according to the invention.
The granulation system is indicated as a whole by the reference numeral 1. It comprises a melt tank 2 from which a product melt M is conveyed by way of a pipeline 3 to a cooler 4 by means of a pump 18. The product melt M is supercooled in the cooler. From the cooler it passes by way of a pipeline 23 to a high-speed mixer 5. Such a mixer is described, for example, in company brochure No. wd 10.84 Rec.-d-26.3000 M of Gebriider i dige Maschinenbau-GmbH, Elsener Str. 7-9, Postfach 2050, D-4790 Paderborn. The product melt M is metered or finely sprayed into the high-speed mixer 5 by means of spray nozzles 20 or distributing tubes and, during that operation, comes into contact with a powder P, a powder mixture or with a crystallisate that has been centrifuged and then washed. The powder or powder mixture or crystallisate is stored in a powder silo 6. An amount weighed out using a weighing device 7 is introduced intu the high-speed mixer by way of a pipeline 22. In the mixer 5, the atomised product melt droplets settle on the powder or the crystallisate which acts like a crystallisation seed and generally induces rapid crystallisation. The granules formed are conveyed by way of a pipeline 24 to a drier 8, for example a moving bed drier or a fluidised bed drier, and are there dried and/or cooled. The dried and/or cooled granules are finally removed from the drier 8 by way of a pipeline 9.
Before the product melt M is supercooled in the cooler 4, it is mixed with a solvent S which, by means of a pump 19, is conveyed by way of a pipeline 21 out of a solvent tank 16 and to a mixing device 17. As a result of mixing the product melt M with the solvent S, the viscosity of the product melt is greatly reduced, for example from the range of approximately 1000 to over 100 000 mPas to the range of approximately 30 to 1500 mPas. At the same time, the wetting capacity of the product melt M in respect of the powder, crystallisate or powder mixture is substantially increased. The product melt/- S solvent mixture is supercooled in the cooler 4, preferably to within the metastable range of the solubility curve. It is thus ensured that the atomised product melt/solvent mixture crystallises very rapidly in the high-speed mixer 5 when it comes into contact with the powder, powder mixture or crystallisate P. The temperature of the product melt/solvent mixture is preferably so regulated that the mixture does nct boil at the spray outlet 20. It will be understood that the pipeline 23 between the cooler 4 and the high-speed mixer 5 is for that purpose constructed to be heatable in a regulated manner. For example, the pipeline 23 is a double-walled pipe in which circulates a heating liquid, the temperature of which can be adjusted.
In the mixing device 17, product melt M is mixed continuously with the solvent S. In order to supersaturate the solution, the product melt/solvent mixture is supercooled.
Starting from the solubility equilibrium temperature (at which there exists a saturated solution) the product melt/solvent mixture is supercooled by up to 70 0 C. The degree of supersaturation increases with the degree of supercooling.
In the regulation of the temperature of the supersaturated solution, care is preferably taken that the temperature of the supersaturated solution is kept lower than the boiling temperature of the solvent. If the product melt/solvent mixture is mixed and transported under elevated pressure the temperature can be higher, and it is also found that smaller amounts of solvent S will suffice. A superpressure of from approximately 0 bar to approximately bar is preferably set.
L -4- In order to prevent the evaporation of solvent from the product melt/solvent mixture and the commencement of crystallisation, which may cause the pipes to become clogged, the mixing of the solvent S with the product melt is carried out in a closed system, care being taken that the system is free of pockets of gas.
It is especially advantageous if the mixing device 17, in which the product melt M is mixed with the solvent S, is a static mixer. Such static n:ixers are widely used in chemical synthesis and are described, for example, in an article by Adolf Heierle "Statische Mischer-Wgirmeaustauscher", in chemie-anlagen verfahren 7/89. With regard to the S. process according to the invention, the advantages of a static mixer result especially from the fact that the system i free of pockets of gas. In addition, it has no moving parts, is easy to clean and is inexpensive. It would, however, also be possible to use a rotor-stator mixer system instead of a static mixer.
The obtainable size of the granules produced can be altered by varying the ratio of the amounts of the solvent S and the product melt. The quantitative ratio is preferably so adjusted that granule sizes of from approximately 0.15 mm to approximately 1 mm, with a range of fluctuation of up to approximately 0,3 mm, are obtained.
In the process according to the invention for the production of fine granules, polar solvents, such as, fc example, methanol, isopropanol or water, are preferably used. The solvent S is recovered when the granules are dried in the drier 8, which, apart from comprising an inert gas circuit 12 for providing inert gas heated in a heater 11, also comprises a filter 13, a condenser 14 and a solvent separator 15 by means of which the solvent S evaporated off in the drier can be recovered in known manner.
By mixing the product melt with a solvent, the viscosity of the product melt is greatly reduced, as a result of which many highly viscous product melts can also be granulated in a high-speed mixer. In addition, the mixing of the product melt with the solvent also increases to a marked degree the wetting capacity of the atomised product melt in respect of the powder, powder mixture or crystallisate, as a result of which the crystallisation time is greatly reduced. The process according to the invention is accordingly also suitable for the granulation of product melts of antioxidants, stabilisers or light-protective agents, which, in the unmixed state, usually have too high a viscosity. The supercooling of the product melt/solvent mixture ensures spontaneous crystallisation in the high-speed mixer.
As a result, incrustation of the walls of the high-speed mixer is prevented, and the formation of lumps, which could clog the pipelines, is obviated. The temperature control of the process according to the invention is such that undesired crystallisation in the pipelines or in the cooler is largely excluded.
The process according to the invention can be used for powders comprising one or more components. That is to say, apart from pure substances, it is also possible to granulate powder mixtures in fine particle sizes. The components of the powder mixtures may be pre-mixed or may be mixed directly in the high-speed mixer in an appropriately lengthened mixing part. For example, one of the components is provided as the product melt which is mixed with the solvent before it is preferably supercooled and metered or sprayed into the high-speed mixer.
The reference numerals in the following claims do not in any way limited the scope of the respective claims.
*oe*
Claims (12)
1. A process for the production of fine granules, in which a product melt from a melt tank is supercooled, and then metered or sprayed into a high-speed mixer and brought into contact with dry powder, powder mixtures or also with centri- fuged and then washed crystallisate from a silo crystallisation giving rise to granules which are discharged from the high-speed mixer subsequently driea and/or cooled in a drier for example a moving bed drier or a fluidised bed drier, and then removed from the drier in which process the product melt is mixed with a solvent prior to cooling, as a result of which its viscosity is greatly reduced and its wetting capacity in respect of the powder, the crystallisate or the powder mixtures is substantially increased, the product melt/solvent mixture is supercooled to within the metastable range of the solubility curve so that rapid crystallisation commences in the high-speed mixer and the temperature of the product melt/solvent mixture is so regulated that the mixture does not boil at the spray outlet (20) in the high-speed mixer
2. A process according to claim 1, wherein the product melt/solvent mixture is produced on-line in the form of a supersaturated solution by supercooling, the product melt/solvent mixture being supercooled by up to approximately 70 0 C starting from the solubility equi- librium temperature.
3. A process according to claim 2, wherein the temperature of the supersaturated solution is kept lower than the boiling temperature of the solvent.
4. A process according to any one of the preceding claims, wherein the mixing of the product melt and the solvent is carried out under elevated pressure, a super- pressure of from approximately 0 bar to approximately 5 bar being selected.
A process according to any one of the preceding claims, wherein the mixing of the product melt and the solvent is carried out in a closed system without pockets of gas.
6. A process according to any one of the preceding claims, wherein the mixing of the product melt and the solvent is carried out in a static mixer pA;IWIIDOC.*\AI:.. 5 24 .3 3"9 -7-
7. A process according to any one of the preceding claims, wherein a polar solvent is used as the solvent
8. A process according to claim 7 wherein the polar solvent is methanol, isopropanol or water.
9. A process according to any one of the preceding claims, wherein the size of the granules is varied by varying the ratio of the amounts of the solvent and the product melt
10. A process according to claim 8, wherein the ratio of the amounts of the solvent and the product melt is so adjusted that the size of the granules is from approximately 0.15 mm to approximately 1mm.
11. A process according to any one of the preceding claims, wherein the product melt (M) S 15 is an antioxidant, a stabiliser or a light-protective agent. 9e
12. A process according to any one of the preceding claims, wherein, by mixing the product melt with the solvent the viscosity of the product melt is reduced from the range of approximately 1000 to over 100 000 mPas to the range of approximately 30 to 1500 mPas, and its wetting capacity in respect of the powder, the crystallisate or the powder mixtures is substantially increased. DATED this 30th day of August 1996, o 9 25 CIBA GEIGY By Its Patent Attorney DAVIES COLLISON CAVE A7-19521/A Process for the production of fine granules Abstract In a process for the production of fine granules, a product melt from a melt tank is preferably supercooled, and then metered or sprayed into a high-speed mixer and there brought into contact with dry powder, powder mixtures or also with centrifuged and then washed crystallisate from a silo During that operation, granules are formed by crystallisation, which are discharged from the high-speed mixer subsequently dried and/or cooled in a drier for example a moving bed drier or a fluidised bed drier, and then removed from the drier Prior to cooling, the product melt is mixed with a solvent as a result of which its viscosity is greatly reduced and its wetting capacity in respect of the powder, the crystallisate or the powder mixtures is substantially increased. The product melt/solvent mixture is then supercooled preferably to within the metastable range of the solubility curve so that very rapid crystallisation commences in S the high-speed mixer During that operation, the temperature of the product melt/- S° solvent mixture is so regulated that the mixture does not boil at the spray outlet (20) in the high-speed mixer (Fig.)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEEP93810253 | 1993-04-08 | ||
| EP93810253A EP0619137B1 (en) | 1993-04-08 | 1993-04-08 | Process to prepare finely granulated material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU5922394A AU5922394A (en) | 1994-10-13 |
| AU675288B2 true AU675288B2 (en) | 1997-01-30 |
Family
ID=8214947
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU59223/94A Ceased AU675288B2 (en) | 1993-04-08 | 1994-03-31 | Process for the production of fine granules |
Country Status (9)
| Country | Link |
|---|---|
| EP (1) | EP0619137B1 (en) |
| JP (1) | JPH07132220A (en) |
| KR (1) | KR100327679B1 (en) |
| CN (1) | CN1074940C (en) |
| AU (1) | AU675288B2 (en) |
| CA (1) | CA2120659A1 (en) |
| DE (1) | DE59308701D1 (en) |
| ES (1) | ES2118212T3 (en) |
| SK (1) | SK280446B6 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IL113562A (en) * | 1995-05-01 | 1999-08-17 | Bromine Compounds Ltd | Process for the production of finely granulated solid chemical compounds |
| DE19541242A1 (en) † | 1995-11-06 | 1997-05-07 | Hoechst Ag | Storage-stable plastic additives |
| ATE222135T1 (en) * | 1995-11-20 | 2002-08-15 | Unilever Nv | METHOD FOR HYPOCOOLING |
| GB9625415D0 (en) * | 1996-12-06 | 1997-01-22 | Agglomeration Technology Ltd | Method of coating particulate matter |
| JP3962703B2 (en) * | 2003-05-09 | 2007-08-22 | 東都化成株式会社 | Method for crystallizing organic oligomer |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4578021A (en) * | 1983-11-01 | 1986-03-25 | Santrade Ltd. | Apparatus for the production of granules from two-phase mixtures |
| US5006284A (en) * | 1989-06-14 | 1991-04-09 | Ciba-Geigy Corporation | Granules of alkyl esters containing hydroxyphenyl groups |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1592512B2 (en) * | 1966-09-12 | 1973-02-15 | Solvay & Cie,Brüssel | PROCESS FOR THE MANUFACTURE OF GRANULATED FERRICHLORIDE HEXAHYDRATE |
| DE1771558B1 (en) * | 1968-06-08 | 1970-12-03 | Quarzwerke Gmbh | Process for coating fine-grain bulk material, in particular quartz sand and quartz powder |
| US4231924A (en) * | 1976-09-23 | 1980-11-04 | Abbott Laboratories | 4-N-Acylfortimicin B derivatives and the chemical conversion of fortimicin B to fortimicin A |
| US4213924A (en) * | 1978-06-19 | 1980-07-22 | Tennessee Valley Authority | Granulation and coating by improved method of heat removal |
| US4540546A (en) * | 1983-12-06 | 1985-09-10 | Northeastern University | Method for rapid solidification processing of multiphase alloys having large liquidus-solidus temperature intervals |
| DE3635313A1 (en) * | 1986-10-17 | 1988-04-28 | Bayer Ag | METHOD FOR PRODUCING GRANULES |
| DE3863187D1 (en) * | 1987-01-20 | 1991-07-18 | Dow Chemical Co | PRODUCTION OF GRAINY BIPHENOLS. |
-
1993
- 1993-04-08 ES ES93810253T patent/ES2118212T3/en not_active Expired - Lifetime
- 1993-04-08 EP EP93810253A patent/EP0619137B1/en not_active Expired - Lifetime
- 1993-04-08 DE DE59308701T patent/DE59308701D1/en not_active Expired - Fee Related
-
1994
- 1994-03-31 AU AU59223/94A patent/AU675288B2/en not_active Ceased
- 1994-04-06 CA CA002120659A patent/CA2120659A1/en not_active Abandoned
- 1994-04-06 SK SK392-94A patent/SK280446B6/en unknown
- 1994-04-07 CN CN94104610A patent/CN1074940C/en not_active Expired - Fee Related
- 1994-04-07 KR KR1019940007227A patent/KR100327679B1/en not_active IP Right Cessation
- 1994-04-08 JP JP6095608A patent/JPH07132220A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4578021A (en) * | 1983-11-01 | 1986-03-25 | Santrade Ltd. | Apparatus for the production of granules from two-phase mixtures |
| US5006284A (en) * | 1989-06-14 | 1991-04-09 | Ciba-Geigy Corporation | Granules of alkyl esters containing hydroxyphenyl groups |
Also Published As
| Publication number | Publication date |
|---|---|
| ES2118212T3 (en) | 1998-09-16 |
| CN1074940C (en) | 2001-11-21 |
| EP0619137B1 (en) | 1998-06-17 |
| SK280446B6 (en) | 2000-02-14 |
| KR100327679B1 (en) | 2002-06-20 |
| EP0619137A1 (en) | 1994-10-12 |
| JPH07132220A (en) | 1995-05-23 |
| SK39294A3 (en) | 1994-11-09 |
| CA2120659A1 (en) | 1994-10-09 |
| CN1093300A (en) | 1994-10-12 |
| AU5922394A (en) | 1994-10-13 |
| DE59308701D1 (en) | 1998-07-23 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MK14 | Patent ceased section 143(a) (annual fees not paid) or expired |