Two-stage roll mill

FIELD: process engineering.

SUBSTANCE: proposed roll mill comprises first rolls to crush material to first preset size, and adjustable second rolls intended for additional grinding a fraction of grist with first preset size particles to second preset size.

EFFECT: provision of desirable distribution of particles.

4 cl, 14 dwg

 

The technical field

The present invention relates to methods and devices for grinding coffee beans or similar materials and, more specifically, to methods and devices for grinding coffee beans or similar materials with obtaining both large and small particles and/or any desired particle size distribution (distribution of particle sizes).

The level of technology

Making a Cup of good espresso is often regarded as a form of art. Traditionally, the best espresso Barista prepares, people with high qualifications in relation to the control variables to ensure proper brew a Cup of espresso. Among these variables are the temperature and pressure of the water used during cooking, the dose of coffee, its freshness, humidity, particle size, pressure compacting etc. Named variables contribute to the resistance that coffee creates to shed water and which allows water to make the coffee brewing process.

To ground the dose of coffee, Barista usually uses an adjustable blade (drums) the grinder. However, the size of the particles obtained in such a grinder, can vary within wide limits. As a consequence, the variability of the distribution of particle sizes of coffee may not have the desired taste. For example, in the case pomolovka too many large particles and small particles of coffee may be respectively nedawareness or digested. While an excess of fine particles may give excessive bitterness.

In this regard, there is a need for methods and devices that provide repeatable desired distribution of particle sizes. While it is preferable that these methods and devices can be configured to receive any desired distribution of particle sizes.

Disclosure of inventions

This paper presents a mill for grinding material. This mill may include first rolls for grinding material, essentially, to the first predetermined particle size and a second, adjustable rollers for grinding portion of the grinding particles of the first size, essentially, to the second predetermined particle size.

Thus, the mill may be a roller mill. The first rolls may contain a pair of crushing rolls. In the first part of the rolls may also include a pair of rolls for additional grinding. The first predetermined particle size may be from 200 to 300 microns. Second, adjustable rolls may contain a couple of rolls of a fine grind. The length of the second adjustable rolls may be less than the length of the first roll, for example, it may be about half the length of the first roll. The degree of use of the second adjustable rolls together with the first rollers can betweren in the range from zero to about 100%. The second predetermined particle size may be at least about 40 microns. Second, adjustable rolls may contain adjustable by the position of the roller and the fixed roller.

This paper also presents a grinder for grinding coffee beans. It contains the crushing rolls to obtain particles of ground coffee, rolls for additional grinding and give the particles of ground coffee, essentially, the first specified size and adjustable rolls fine grind for subsequent grinding fraction of particles of ground coffee with making them, essentially, the second predetermined particle size.

Herein disclosed is also a method of grinding coffee beans. This method comprises grinding the first of many coffee beans through the first group of rolls up to the size of about 250 μm, the grinding of the second set of coffee beans through the second group of rolls up to the size of about 40 microns, and combining the first set of coffee beans and the second set of coffee beans. The size of the coffee particles of about 250 microns, can cover the size range 250±20 μm, and the size of the coffee particles of about 40 μm, the interval size of 40±10 μm. Thus the second set of coffee beans can be part of the first set of coffee beans.

A brief description of the drawing the th

Figure 1 in the top view, in perspective image shows a cartridge for use with a mill according to the invention.

In figure 2 the cartridge of figure 1 shows in perspective representation on the form below.

Figure 3 cartridge of figure 1 shows in axial section.

Figure 4 cartridge of figure 1 is shown in the top view.

Figure 5 cartridge of figure 1 shown in the bottom view.

Figure 6 in the axial cross-section showing the cartridge with cover.

7 in the axial cross-section showing the cartridge placed in it the material for cooking.

On Fig proposed mill shown in the front view.

Figure 9 mill on Fig presents on the side view.

On figa-10D presents a perspective image of the rolls of a fine grind for use in the mill Fig.

Similar or identical elements in the various drawings have a similar or identical sign.

The implementation of the invention

Figure 1-7 presents a variant of the cartridge 100, which can be used in conjunction with the invention. The cartridge 100 can be used, for example, cooking servings of the drink described in U.S. patent No. 6786134 owned by the applicant of the present invention, or in other systems, cooking drinks. Although in this description are described in detail, it is the cartridge 100, instead it can be used and other containers for receiving particles after the grinding is. In the cartridge 100 can be placed a certain amount of material 105 used in cooking, such as ground coffee, tea leaves, powders or mixed material of a different type, flavoring or other additives, or any other materials.

The cartridge 100 may have essentially the shape of the Cup 110. The Cup 110 may be made of a conventional thermoplastic material, such as polystyrene, polyethylene or polypropylene. Alternatively, you can also use stainless steel or other corrosion-resistant materials. The Cup 110 may be made rigid enough to withstand the heat and pressure that occur in the cycle of cooking, without giving to drink some undesirable taste. The term "rigid" as applied to the Cup 110 admits that she may be slightly bend or deform under application of pressure.

The Cup 110 may have a side wall 120, essentially in the form of a circular cylinder and essentially flat base 130. The Cup may have other forms. The side wall 120 and the base 130 of the Cup 110 may be molded as a single part. Alternative manufactured separately lateral wall 120 and the base 130 may be rigidly interconnected. The side wall 120, a base 130 and the Cup 110 may have any suitable diameter, allowing you to use the AMB Cup in the system of cooking servings of drink or devices of a similar type. The side wall 120 and the base 130 of the Cup 110 may be any suitable for use shapes or sizes. So, the side wall 120 may be straight, inclined, stepped, or curved. As an example, the side wall 120 may have an inner diameter 39,3 mm with the wall thickness of 1.1 mm, but can be any other suitable size.

The cartridge 100 may have different depths depending on the amount of material 105 for cooking that you want to put. If the cartridge 100 is used for cooking 355 ml drink, its overall height can be, for example, 28,7 mm, useful height of its internal volume of 17.1 mm Thus, the ratio of height to diameter of the cartridge 100 with a volume of 355 ml can be to 0.73 for total height and 0,435 for useful height. The cartridge 100 polypropylene may have a mass of about 6.4,

The cartridge 100 for cooking 237 ml drink can have a total height of 22.5 mm and a clear height of 11.8 mm In this embodiment, the ratio of height to diameter will be 0.57 for total height and 0.3 for useful height and weight cartridge polypropylene, 5.8,

The specified ratio between the diameter and depth give the Cup 110 and the cartridge 100 generally sufficient strength and rigidity with minimum consumption of material: the weight of the cartridge 100 during its manufacture, N. the example, from homopolymer polypropylene may be 5-8, While the Cup 110 and the cartridge 100 as a whole is able to withstand temperatures up to 93°C for 60 s or more when the hydraulic pressure in excess of 1 MPa. Although the cartridge 100 with the specified size ratio may slightly bend or deform, he was, nevertheless, able to withstand the expected pressure of the water passing through it. These dimensions and specifications are given only as an example.

In the base 130 can be performed with a number of holes 140, which may extend along the entire thickness of the substrate 130. Holes 140 may have an essentially circular shape with a diameter of about 1.6 mm, but may be any other suitable shapes and sizes of holes. In the present embodiment, there are 54 holes 140, but there are other of their number. The number and size of holes 140 are selected from conditions provide the required pressure drop when using a cartridge 100 with the above dimensions.

The base 130 can be supplied also formed on the ribs 150. You can use any desired profile, the number and/or position of the ribs 150. This example uses the round inner edge, round the outer edge and the radial ribs. Ribs 150 may have a height of about 1 mm, though other values of the height. Design the Oia ribs 150 is selected to provide additional strength and stability of the cartridge 100 in the chain with minimum material consumption.

The side wall 120 of the cartridge 100 may have an upper flange 160. The upper flange 160 may have an essentially flat top 170 width of 3.45 mm and a vertical size of 3.4 mm Dimensions flange 160 can be selected depending on the size of the respective parts of the system of preparation of portions of the drink (or similar system), which is the cartridge 100, as well as on the expected load of the hot water using the minimum amount of material. This requirement is due to the fact that the cartridge 100 in the submission process water can be maintained only by its flange 160.

The side wall 120 of the Cup 110 may also have grooves 180. In the present embodiment, there may be three grooves 180. However, depending on the number placed in the Cup material, the number of grooves 180 may be different. Thus, in the toner cartridge designed for the amount of drink that is equal to 237 ml, you can only use two grooves 180. Grooves 180 may pass continuously over the entire circumference of the inner surface of the side wall 120, or have gaps.

Grooves 180 may interact with lid 190, which may have the edge 200, made essentially wedge-shaped at its perimeter to facilitate its entry into the groove 180. The presence of grooves 180 ensures that the cover 190 is secured in the desired position. Chrome is and 200 may be continuous or may be discontinuous in accordance with the shape of the grooves 180. Cover 190 preferably has a deflection inward, i.e. is concave. In the manufacture of the cover of propylene its mass may be about 0.8,

Depending on the amount of material 105 for cooking, you want to put in the cartridge 100, the cover 190 can be inserted into one or other of the grooves 180. Performing a cover 190 concave allows compact (compact) used material 105 at the appropriate pressure and to prevent any bias. The cover can make the required effort compacting the material 105 and hold it under load, acting essentially on the principle washer Bellville (Bellville washer). The use of cover 190 for compacting used for brewing material 105 also allows you to speed up the filling process cartridge 100 specified material. In the cover 190 can also be made holes 210 in order to provide the possibility of passage through the cartridge the water coming from the system cooking servings of drink or similar device. For some variants of this system using the cover 190 may be optional.

The cartridge 100 may be covered by one or several layers of filter paper 220, which may apply a standard filter paper used to collect material 105 while providing a passage from Vose prepared her drink. However, the filter paper 220 must have sufficient strength, rigidity and/or porosity that she was not involved in the holes 140 of the base 130 and/or did not allow small particles of material 105 to block or clog these holes. Clogging of the holes 140 can lead to an imbalance of pressure on the cartridge 100. Taking into account the stiffness of the paper 220, which provides resistance to deformation, the diameter of the holes 220 of the base 130 of the Cup 110 can be larger for a corresponding increase in flow through these holes.

As an example, filter paper 220 may be made from a combination of cellulose fibers and thermoplastic. Suitable grades of filter paper sold by the company J.R.Crompton (USA) under the designations PV-377 and PV-S. In particular, the material PV-347C may have a surface density of about 40 g/m2and burst pressure wet about 62 kPa. Can be used and other similar materials. You can also use multiple sheets with the same or different characteristics.

The cartridge 100 may have several layers of filter paper 220. In the present embodiment, it may have the upper filter layer and the lower filter layer, which is usually placed at a desired position without the use of adhesives. The upper filter layer long is the super should have the same strength, that and the lower filter layer. This top layer provides a dispersion of water and prevents clogging system for cooking servings of drink or similar device, particles of ground material. Itself is used for brewing material 105 may be placed between layers of filter paper 220, preferably being in contact with the side wall 120, i.e. filter paper 220 does not cover the side surface of the Cup 110. This embodiment allows water to pass through itself the material used is 105 instead of passing through the Cup 110 on filter paper 220.

Used for brewing material 105 may be placed in a foil bag or other airtight material. This package can be used to hold the material used 105 inside it fresh and out of contact with the surrounding air. Alternatively, the cartridge 100 individually or in a group may be entirely stored in the foil pouch until its use.

Used for brewing material 105 is typically prepared in the mill 250. Mill 250 may take the original (raw) material, which in this example are coffee beans, and grind it on the coffee particles. Can be used and other materials. As shown in Fig-10, mill 250 preferably is a roller is elnita. Such mills are produced, for example, Modern Process Equipment, Inc. (USA), as a model 660FX, 666EX.WC, 888EX.WC, etc. As will be shown, mill roller 250 is preferable mills of other types, such as shock.

In this example, the mill 250 can have three stages of the rolls. As the first stage may use a pair of crushing rollers 260. The second step may be formed by a pair of rollers 270 for additional grinding. The final step may consist of a pair of rolls 280 finely. Alternatively, it may use any number of rollers 260, 270, 280. Rollers 260, 270, 280 may be made adjustable, in order to obtain particles of any given size. Mill 250 may include an input hopper 290 and the output node 300. Mill 250 may have other configurations.

As shown in figa-10D, the mutual position of the rolls 280 fine grind can adjust to control the amount of small particles that are complementary to larger particles. In the present example, the utilization of rollers 280, smaller sizes can be changed from zero to about 100%. When this rolls 280 fine grind can have a smaller length than the remaining rollers 260, 270. For example, if the rollers 260, 270 have a length of 76.2 cm, length rolls 280 fine grind can be 38,1 see In this case when max is th degree of the use of rolls of a fine grind about 50% of the particles will be small particles. The degree of use of rollers 280 fine grind can be set to any value. In addition, the rollers 280 can be of any length. In the absence of use (i.e. overlap) rolls 280 (which corresponds figa) small particles will be absent, the Level of use equal to 20% (see figv), will give about 10% of fine particles, the degree of equal to 50% (see figs). will give about 25% of fine particles, and full use (100%) will give about 50% of small particles. Thus, you may receive any desired proportion of small particles whose size ranges from 40 μm. This may be obtained in any desired size.

Adjustable position can be done only one of the rollers 280 finely ground, while the second roller can be fixed. After obtaining the specified overlap by adjusting the adjustable position of the roll 280, it can be fixed with suitable clamp or any other suitable circuit means.

Material 105 for cooking (in the present embodiment, the coffee beans may be placed in the input hopper 290, where it will be held between the crushing rollers 260, which will break up this material 105, essentially, to the desired dimensions. It then passes through rollers 270 for additional grinding. R is sloanie between the rollers 270 is selected so as in order to obtain particles with the desired size. For this option given the size of the particles may be, for example, 200-300 μm, and for some products the optimum particle size of 250 microns. Can be ensured, and other desirable dimensions. Relatively large particles generated when passing through the crushing rollers rollers 260 and 270 for additional crushing, help prepare the drink with the desired strength, intensity of flavor and other characteristics.

If you want to have a certain proportion of fine particles, rolls 280 fine grind installed in the mutual position of this desired proportion. As will be explained in more detail hereinafter, the use of rollers 280 fine grind affects the resistance to flow of water and therefore the cooking time of the used material 105. The increase in the proportion of smaller particles increases the flow resistance and the cooking time.

Mill 250 may also contain the sealant 310, placed under the rollers 280 finely. The sealant 310 may contain knives, serving to give the individual particles of more uniform size and shape. In particular, the particles become more uniform spherical shape and may become more solid. Compaction of the particles leads to a modification of its the of drink, because changes in density affect the characteristics of the currents passing through them a stream.

In addition to the formation of uniform spherical particles of the sealant 310, apparently, reduces the number of fine particles as a result of "gluing" ("clumping") of these particles into larger. This "bonding" may be due to the presence of particles in oils, giving them more energy, or other factors. In particular, the content of solids in the coffee after the seal may be about 6%. At the same time without seal this content can reach about 7.5%, which gives the final product, which may be too strong. The main result of compaction is getting narrower, i.e. homogeneous distribution of particles. Although the operation of the seal was used to facilitate the packing of coffee in the packaging, it was not previously used to modify the characteristics of the beverage obtained from the milled material.

As shown above, roller mill, apparently, provide improved distribution of particle sizes, which becomes more stable. Mill roller 250 gives a smaller number of large particles, the extraction of which may be incomplete and that can make a drink optimal taste, and a smaller number of very small particles that can change the better the taste of the drink due to excessive extraction and giving him bitter. Such particles also have an influence on the pressure in the cartridge 100, as it is inversely proportional to the square of the particle size, i.e. increases with decreasing particle size.

Comparison of the roller and beater mills (mills) is illustrated at 11. The size distribution of particles obtained on the roll grinder grinding for coffees "Rain Forest" (left figure 11) has a border of about 8.0 µm, whereas a similar distribution to a grade of "Milano" (obtained on the blade coffee grinder) continues to 0.1 μm. Similarly, the roll grinder gives a smaller number of larger particles.

Figure 11 shows that the size of more than 80% of the particles formed on the roll grinder, distributed in the range of 220 to 250 μm, whereas 99% of these particles have sizes in the interval 8-650 μm. In the more General case 75% of the coffee particles can have a size distribution in the range of 200-300 μm. Although reproducible distribution of particles at the maximum of the distribution at 250 μm provides improved quality of the drink, it might be desirable to have a certain amount of fine particles to ensure that in the process of cooking the required flow resistance and pressure. The lack of a sufficient number of small particles may result in too rapid passage of water. In this case, from 10% to 20% of the particles in the distribution may have the ü size up to 40 microns. This may be obtained in any desired fraction of small particles.

Thus, mill roller 250 provides a narrower and more stable distribution of particle sizes. You can adjust the amount of fine particles to limit the bitterness of the drink, while maintaining reproducible pressure on the material. This distribution of particle sizes gives coffee drink with improved and reproducible taste.

When using the cartridge 100 to the base 130 of the Cup 110 of the cartridge may be placed in filter paper 220. Then, on this layer, place the required number used for brewing material 105. After that, if necessary, to the material 105 may be imposed an additional layer of filter paper. Then the inside of the Cup 110 can enter the cover 190 to compacted material 105 with the application of force 133 N (the value of the applied force can be varied). After the cover 190 has provided the compacting of the material used 105, its edge 200 is inserted into the groove 180, made in the side wall 120 of the Cup 110. The cartridge 100 may thereafter be sealed in the package or otherwise prepared for use with a system for cooking servings of a beverage or other device.

The pressure of water flowing through the cartridge 100 can be varied according to the t character used for brewing material 105. Hot water under pressure may be fed into the cartridge 100 from any suitable source. Flow characteristics of water flowing through the cartridge 100, depend on its geometry and dimensions, nature and quantity of the used material 105, the pressure and temperature of water and the time of cooking. The cooking temperature is usually chosen in the range of 85-100°C or slightly higher, and the pressure is in the range of 1.0-1.4 MPa. Changing any of these parameters may cause changes in the character of the drink. As noted above, it is desirable to maintain uniformity of particle size. Extraction of soluble solids from the particles of ground coffee, not having the required dimensions, usually turns out to be excessive or insufficient. The use of mill 250 promotes uniformity and stability of particle sizes. The application of the sealant 310 also improves the uniformity of particle sizes. Plugging of the particles of coffee helps to obtain a uniform flow of liquid through the cartridge 100. As mentioned above, the size of the particles affect the backpressure, which is "work" for the preparation of the drink.

1. The method of grinding coffee beans, including:
the grinding of the first set of coffee beans through the first group of rolls up to the size of about 250 μm, the grinding of the second set coffee what's grains through the second group of rolls up to the size of about 40 μm, and combining the first set of coffee beans and the second set of coffee beans.

2. The method according to claim 1, characterized in that the particle size of coffee of about 250 μm, covers the size range 250±20 microns.

3. The method according to claim 1, characterized in that the particle size of coffee of about 40 μm, covers the size range of 40±10 μm.

4. The method according to claim 1, characterized in that the second set of coffee beans is part of the first set of coffee beans.



 

Same patents:

Two-stage roll mill // 2413449

FIELD: process engineering.

SUBSTANCE: proposed roll mill comprises first rolls to crush material to first preset size, and adjustable second rolls intended for additional grinding a fraction of grist with first preset size particles to second preset size.

EFFECT: provision of desirable distribution of particles.

4 cl, 14 dwg

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