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Patent Searching and Data


Title:
A METHOD FOR OPERATING A BALL MILL AND A MILLING SYSTEM
Document Type and Number:
WIPO Patent Application WO/2015/108412
Kind Code:
A1
Abstract:
The present invention relates to a method for treating a viscous mass comprising solid components in a grinding system, especially a fatty mass with solid components, said grinding system comprising a mixer and a grinding device, said method comprising the steps of: feeding into a mixer the mass to be treated; repeatedly circulating the mass to be treated by means of a displacement device from the mixer through a supply pipe to the grinding device and through a return pipe back to the mixer for reducing the size of said solid components in said grinding device; and further comprising the step of: removing from the system at least part of the treated mass through a branch-off provided in the return line when a predetermined grinding fineness has been obtained; and feeding into the mixer a new mass to be treated and at least partly displacing the new mass to be treated in said grinding device by means of said displacement device and as a consequence removing at least another part of said treated mass from said system.

Inventors:
HAMMINK JAN (NL)
Application Number:
NL2014/050921
Publication Date:
July 23, 2015
Filing Date:
December 30, 2014
Export Citation:
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Assignee:
CAOTECH BEHEER B V (NL)
International Classes:
A23G1/00; A23G1/10
Foreign References:
EP0442544A21991-08-21
Other References:
SIEGFRIED BOLENZ ET AL: "Improving particle size distribution and flow properties of milk chocolate produced by ball mill and blending", EUROPEAN FOOD RESEARCH AND TECHNOLOGY, vol. 238, no. 1, 17 September 2013 (2013-09-17), pages 139 - 147, XP055135606, ISSN: 1438-2377, DOI: 10.1007/s00217-013-2094-7
"Industrial Chocolate Manufacture and Use", 12 December 2008, WILEY-BLACKWELL, Oxford, UK, ISBN: 978-1-40-513949-6, article G. R. ZIEGLER ET AL: "Particle Size Reduction", pages: 142 - 168, XP055135679, DOI: 10.1002/9781444301588.ch7
Attorney, Agent or Firm:
PLAGGENBORG, Menko Bernard (Busplein 36, KV Almere, NL)
Download PDF:
Claims:
C L A I M S

1. A method for treating a viscous mass that comprises solid com¬ ponents in a grinding system, especially a fatty mass with solid components, said grinding system, comprising a mixer and a grinding device, said method comprising the steps of :

- feeding into a mixer the mass to be treated,

- repeatedly circulating the mass to be treated by means of a dis¬ placement device from the mixer through a supply pipe to the grinding device and through a return pipe back to the mixer for reducing the size of said solid components in said grinding de- vice,

characterized in that the method also comprises the step of:

- removing from the system, at least part of the treated mass through a branch-off provided in the return line when a predetermined grinding fineness has been obtained, and

- feeding into the mixer a new mass to be treated and at least partly displacing the new mass to be treated in said grinding de¬ vice by means of said displacement device and as a consequence re¬ moving at least another part of said treated mass from said sys¬ tem.

2. A method according to claim 1, wherein said grinding device is a ball mill.

A method according to claim 1 or 2, wherein said fatty mass is mass comprising at least one of the following components: cocoa ss, milk powder, whey powder, lecithin, flavor, and sugar.

4. A method according to claims 1, 2 or 3, wherein a volume of the new mass to be treated is larger than the mixer's volume.

5. A method according to claim 4, wherein the volume of the new mass to be treated is smaller than the combined volume of the mix¬ er and the grinding device.

6. A method according to any of the preceding claims, wherein the system comprises a storage vessel the volume of which is larger than the mixer's volume. 7. A grinding system, for performing a method according to any of the preceding claims, wherein the grinding system comprises a mixer and a grinding device, said m.ixer on the one hand being connected to the grinding device by means of a supply pipe and a dis¬ placement device being provided for displacing said mass from said mixer to the grinding device, and on the other hand said grinding device being connected to said m.ixer by means of a return pipe, characterized in that a branch off is provided in said return pipe for removing treated mass from said system. 8. A grinding system, according to claim 7, said grinding device comprising a ball mill.

9. A grinding system, according to any of claims 7-8, said displacement device comprising a pump.

10. A grinding device according to any of claims 7-9, comprising a storage vessel, the volume of said storage vessel being larger than the mixer's volume.

Description:
A method for operating a ball mill and a milling system The present invention relates to a method according to the preamble of clam 1. The invention further relates to a grinding system, for performing the method according to claim 7.

Such a method is known in the art. For example, when produc ¬ ing fatty masses that comprise solid components and the like prod- ucts (such as chocolate and cocoa mass; wherein the fatty m.ass comprises at least one of the following components: sugar, milk powder, whey powder, lecithin, flavor and cocoa powder) , hereinafter generally referred to as "fatty mass", a certain amount of a mass to be ground is fed into a mixer after which the said mass is displaced towards a grinding device by means of a displacem.ent device. Said displacement device usually is a pump. When processing a fatty mass, like chocolate and the like, the pump must be suitable for yielding a relatively large delivery head due to the highly viscous character of the said mass. The mass to be treated is circulated several times, such that the said mass passes through said grinding device several times. As a consequence, the particle size of said solid components is reduced in said grinding device. The grinding device may advantageously be a ball mill, as m.arketed by the firm Caotech B.V. from Worm.erveer/NL, for example the types CAO1000, CAO2000, CAO3000 and CAO4000, all of these being so- called "attrition ball mills". After a required particle size dis ¬ tribution is obtained, said grinding method is ended and the treated mass is removed from said system. Such is obtained by re ¬ moving said treated mass through a branch off that is provided in the supply pipe by using said pump. The branch of usually is pro vided somewhere before or after said ball mill; for example, as a branch off in a pipe between the pump and the ball mill, or as a branch off in a pipe between the ball mill and the mixer. However, part of said treated mass that is present in said grinding device will substantially not be removed from the system, since a main part thereof will stick to the grinding facilities. Such especial ¬ ly is obtained when using ball mills. The amount of treated mass remaining in the system may be up to 40% of the total amount of treated mass in said system.

A disadvantage of said known method therefore is comprised of the fact that a large amount of treated mass remains in the sys- tern .

In the art, there is no practical or economical solution for a ball mill, as far as it regards coca, chocolate and chocolate ¬ like products. The so-called 5-roll refiner that is used for pro ¬ cessing chocolate and chocolate-like products is no economic match for a ball mill.

The present invention aims at providing an improved method of the kind indicated in the preamble.

The invention especially aims at providing a method of the kind m.entioned in the preamble that yields a larger output than the systems presently available.

The invention also aims at providing an improved method with which an improved product is obtained.

So as to obtain at least one of the above mentioned advantages, according to a first embodiment the present invention provides a method comprising the features of claim 1. Such method has the advantage that a faster production and a larger output for every batch are obtained.

It has also shown that in the method according to the present invention a considerably smaller particle size distribution is ob- tained than with the methods according to the state of the art.

This may be due to the act that in the known method the subsequent batch is mixed with a large amount of the previous batch and is subjected to the grinding processed again. As a consequence, part of said mass is ground too fine. Such yields a still higher vis- cosity, especially when grinding fatty masses. In its turn, a higher viscosity leads to a larger amount that remains in said grinding device due to its sticky behavior, especially in a ball mill. Therefore, the present invention provides a huge advantage with respect to the method according to the state of the art be- cause the particle size distribution is much smaller. Such syner- getic result was completely unexpected.

It has also shown that temperature control is much better with the present novel method. The temperature of the mass to be treated increases when processing same. With the known method, the starting temperature is larger than with the present method, due to the large amount of treated mass remaining in the system.. The lower starting temperature in the present method provides a lower end temperature of the treated mass, even if the mass is cooled interim. This synergetic effect is completely unexpected as well.

As mentioned above, it is especially preferred for the grind ¬ ing device to be a ball mil. This allows to obtain an accurate grinding, while obtaining a relatively accurate displacement of the mass to be treated within said grinding system as well, yield ¬ ing an accurate grinding of said mass.

As mentioned above, it is preferred that the viscous fatty mass is a fatty mass that comprises solid components that compris- es at least one of the following components: sugar, milk powder, whey powder, lecithin, flavor and cocoa powder as solid components. An example thereof is a mass comprising cocoa butter. The fatty mass may for example be mixed with sugar, milk powder and flavors and be ground in said grinding device until a required particle size distribution is obtained. Regarding production of chocolate or chocolate like products, cocoa mass or cocoa powder, respectively, may be added. Other substances may be added as de ¬ sired to the recipe.

Preference is especially given to a method wherein the volume of the new mass to be treated is larger than the mixer's volume. This renders it possible that when replacing the treated mass with a new mass to be treated, the mixer and a further part of the grinding system is filled with the new mass to be treated. This is contradictory to the state of the art, where only the mixer can be filled with the new mass to be treated.

Therefore, it is preferred that the system comprises a storage vessel, the volume of which is larger than the mixer's volume. In said storage vessel, a stock of mass to be treated may be composed that can be fed into said mixer when a treated mass is to be removed from the system.

It is especially preferred that the volume of the new mass to be treated is smaller than the combined volume of the mixer and the grinding device. Due to the mixer's volume, the amount of new mass to be treated will be added incrementally to said mixer. When removing the treated mass from the system, no ideal plug flow behavior will be obtained in the grinding device. As a consequence, part of the new mass to be treated will reach at the branch off in said return pipe whereas a small part of said treated mass still remains in the system. Although according to the present invention a small part only remains in the system, such amount is very small, maximally 10% and preferably even less than 5%.

According to a further aspect, the invention relates to a grinding system for performing a method according to the present invention as mentioned above, said grinding system comprising a mixer and a grinding device, said mixer on the one hand being con ¬ nected to the grinding device by means of a supply pipe and a dis- placem.ent device being provided for displacing said mass from said mixer to the grinding device, and on the other hand said grinding device being connected to said mixer by means of a return pipe, said grinding system being characterized in that a branch off is provided in said return pipe for removing treated mass from, said system.. In such system, the several embodiments of the method according to the invention can easily be implemented, such that the advantages as stated above are accomplished.

In the system according to the present invention, it is especially preferred that the storage vessel has a larger volum.e than the mixer.

It is especially preferred that the grinding device comprises a ball mill, with the remark that the grinding system is not limited to such ball mill.

SO as to be able to displace the mass through said system, it is preferred that the displacement device comprises a pump.

The invention also relates to a treated mass, obtained with the method according to the present invention or with a grinding system according to the invention. The particle size distribution of such mass is substantially smaller than the particle size dis- tribution of a mass according to the state of the art.

The invention also relates to a fatty mass that comprises ground solid components, obtained with a method according to the present invention or with a grinding system according to the invention. The particle size distribution of such mass is considerably smaller than the particle size distribution of a mass obtained according to the state of the art .

Hereafter, the invention will be further described by means of a drawing. The drawing shows in Fig. 1 a schematic view of a grinding system according to the present invention.

For sake of simplicity, not all parts that are required for a practical embodiment of the invention are shown in the drawing.

Fig. 1 shows a schematic view of a grinding system 1 accord ¬ ing to the invention. Said grinding system 1 comprises a storage vessel 2, being connected to a mixer 4 through a connection pipe 3. Said mixer 4 is connected to a ball mill 6 through a supply pipe 5. A mass to be treated (not visible) is fed through the sup- ply pipe 5 to the bottom 8 of said ball mill 6 by means of a pump 7 from, said mixer 4. In the embodiment shown in the Figure, said mass to be treated runs through said ball mill 6 from the bottom up. At the top 9 of said ball mill 6 the treated mass leaves said ball mill 6 and is returned through a return pipe 10 to the mixer 4. In said mixer, the treated mass is mixed with other content. Subsequently, said mass is fed from said mixer 4 to the ball mill 6 again through supply pipe 5. This treatment is performed for a predetermined time period or as long as necessary until a required particle size distribution of the particles that are present in the mast to be treated is obtained.

Upon finishing the treatment, pum.p 7 displaces treated mass from m.ixer 4 through ball mill 6 and removes same at branch off 11 through drain pipe 12. After said mixer is emptied, a new .ass to be treated is fed from storage vessel 2 into said mixer 4 and, in synchronism with pumping of said treated mass, pumped into ball mill 6 through supply pipe 5. The amount of new mass to be treated that is added to the mixer 4 is such, that no new, unground mass to be treated reaches drain pipe 12. Right before that moment, branch off 11 is closed and the grinding process according to the present invention is continued. Due to the fact that the volume of the mixer is smaller than the volume of new mass to be treated that was added, the new mass to be treated cannot be added in one step to the mixer. As a consequence, after closing branch off 11 the remaining part of the new mass to be treated can be fed into said m.ixer and the treatment cycle can be performed on said new mass to be treated.

The method according to the present invention is extremely suitable for grinding fatty masses, such as mentioned before. A practical application of a fatty mass according to the present in ¬ vention for example consists of production of chocolate products for stuffing and the like.

The invention is not limited to the embodiments as mentioned above and as shown in the drawing. The invention is limited only by the appending claims .

The invention also embodies al combinations of features and steps that have been described herein independently from each oth ¬ er .