Colloid mills, their rotors, stators, and systems and methods including such colloid mills.

Abstract

This invention relates to a colloid mill for reducing the particle size (100) of particles (101) suspended in a first liquid and / or the droplet size of a second liquid emulsified in the first liquid. The colloid mill has a rotor (1) and a stator (2), which are coaxially arranged inside the other. The colloid mill has a material inlet on a first axial side for introducing the suspension or emulsion and a product outlet on a second axial side for discharging the suspension or emulsion. The rotor (1) has a rotor grinding surface (3) facing the stator (2), and / or the stator (2) has a stator grinding surface (4) facing the rotor (1). The rotor grinding surface (3) has grinding teeth (5a, 5b) with shear surfaces (6) and / or shear edges (7), the cross-sectional surface (8a) of which tapers toward the opposite stator grinding surface (4) in the radial direction (R) in a plane perpendicular to the axis of rotation (D), wherein the cross-sectional surface (8a) has a first leg (14a) which is adjacent to the circumferentially extending base side (11a) of the cross-sectional surface (8a), pointing toward the rotation direction (15) of the rotor (1) and forming an angle (α) of 85°–95° with the base side (11).

Description

Technical Field

[0001] This invention relates to colloid mills, systems for processing fatty substances, methods for reducing the particle size of solids suspended in a first liquid and / or the droplet size of a second liquid emulsified in a first liquid, rotors, and stators. Background Technology

[0002] Colloid mills are known in the prior art for dispersing solid and liquid substances to colloidal fineness in a colloid mill by mechanical force or for emulsifying liquids in a liquid.

[0003] For example, solid substances (such as sugar, milk powder, nuts, fruits, or grains) are finely distributed within a fatty substance (such as cocoa butter). Solid and liquid substances added to a colloid mill are referred to as materials in the context of this application.

[0004] Known colloid mills generally comprise a cylindrical or conical housing with a vertical axis. They have a material inlet on one axial side and a product outlet on the opposite axial side. A colloid mill includes a cylindrical or conical stator and a coaxially arranged rotor, the cylindrical or conical stator typically mounted on or integrally formed with the inner wall surface of the housing, the rotor typically within the stator, which has a vertical axis of rotation rotatably supported by the housing and fixedly and coaxially supported by the rotor.

[0005] In the context of this invention, the terms “radial,” “axial,” “rotational direction,” and “circumferential” refer to the axis of rotation of the rotor of the colloid mill.

[0006] The outer surface of the rotor and the inner surface of the stator are each provided with opposing grinding teeth designed as ribs, and the grinding teeth are interspersed with recesses arranged alternately between them, wherein the ribs and recesses extend substantially in the axial direction and have a substantially rectangular shape in cross section.

[0007] Crusher designed with this geometry is shown as prior art, for example, in EP0122608A2.

[0008] To improve output and grinding performance, colloid mills are equipped with grinding teeth. The cross-section of the grinding teeth is serrated in a plane perpendicular to the axis of rotation, that is, it has an approximately trapezoidal or triangular cross-section.

[0009] For example, grinding apparatuses having such geometries are disclosed in CN 2291205Y, EP0775526A1, EP0605169 A1, EP0497526 A2 and EP0122608A2.

[0010] Compared to rectangular shapes, the flat sidewalls of grinding teeth provide more space for the product and can therefore lead to increased production.

[0011] It has been shown that significant heating of the processed material occurs during processing in a colloid mill, which can negatively impact the product, especially when the product is a heat-sensitive food or pharmaceutical product.

[0012] Therefore, the object of the present invention is to overcome the disadvantages of the known technology, and in particular to provide a colloid mill, a system, a method, a rotor, and a stator that allow for efficient pulverization with the lowest possible temperature rise. Summary of the Invention

[0013] The objective of this invention is achieved by a colloid mill, a system, a method, a rotor, and a stator.

[0014] The colloid mill according to the invention is used to reduce the particle size of particles suspended in a first liquid and / or the droplet size of a second liquid emulsified in the first liquid, wherein the first liquid is in particular an aliphatic substance.

[0015] Fatty base substances can be fats or oils. In particular, fatty base substances contain cocoa butter.

[0016] The particles can be solids, such as sugar granules, nuts, fruits, and / or grains. The particles undergo wet grinding in a colloid mill.

[0017] Particles can contain fat in such a way that no liquid needs to be added; and the reduced particles are emulsified in their own fat, which can be considered the primary liquid.

[0018] The colloid mill has at least one rotor and at least one stator, which are coaxially arranged inside the other. Preferably, the rotor is arranged inside the stator or can be attached inside the rotor.

[0019] Alternatively, one could consider the rotor rotating around the stator.

[0020] The rotor may have a rotatable shaft or may be connected to a rotatable shaft, which is set to rotate by a drive device.

[0021] Preferably, the colloid mill has at least one material inlet on a first axial side for introducing particles, liquids, suspensions, and / or emulsions, and at least one product outlet on a second axial side for discharging suspensions or emulsions. The material to be processed can thus flow through the colloid mill in the axial direction.

[0022] The material inlet can be funnel-shaped, allowing the material to enter the grinding chamber between the rotor and stator under the influence of gravity.

[0023] The at least one rotor has a rotor grinding surface facing or to be facing the stator, and / or the at least one stator has a stator grinding surface facing or to be facing the rotor.

[0024] The rotor grinding surface has at least one grinding tooth with a shearing surface and / or shearing edge, the cross-sectional surface of which tapers radially toward the stator grinding surface opposite to or to be arranged opposite to it in a plane perpendicular to the axis of rotation.

[0025] Grinding teeth are raised areas that protrude from the bottom surface of the rotor or stator.

[0026] The raised area has a surface and / or edge that, in the installed state, has the shortest distance to the opposing grinding surface. This surface and / or edge ensures the shearing of the material and thus forms a shearing surface and / or shearing edge.

[0027] The cross-sectional surface has a first leg, preferably a straight first leg, which is adjacent to the circumferentially extending base side of the cross-sectional surface. The first leg points in the direction of rotation of the rotor. This means that the first leg defines the rotation-oriented side of the cross-sectional surface. As the rotor rotates, the first leg moves against the material located in the colloid mill.

[0028] Preferably, the first leg is located on the side surface of the grinding teeth that points in the direction of rotation of the rotor.

[0029] The first leg and the base side form an angle in the range of 80°-100°, preferably 85°-95°. The base side is preferably located on a circle about the axis of rotation.

[0030] Preferably, the first leg is located on a radial line passing through the axis of rotation and is perpendicular to the base side.

[0031] Alternatively or otherwise, the stator grinding surface has at least one grinding tooth with a shear surface and / or shear edge, the cross-sectional surface of which tapers radially toward the rotor grinding surface opposite to or to be arranged opposite to it in a plane perpendicular to the axis of rotation.

[0032] The cross-sectional surface has a second leg, preferably a straight second leg, which abuts the base side of the cross-sectional surface extending circumferentially. The second leg points away from the direction of rotation of the rotor. This means that the second leg defines a side of the cross-sectional surface pointing away from the direction of rotation. During the rotation of the rotor, the material being moved can therefore flow against the second leg.

[0033] The second leg is preferably located on the side surface of the grinding teeth that points away from the direction of rotation of the rotor.

[0034] The second leg and the base side form an angle in the range of 80°-100°, particularly 85°-95°. The base side is preferably located on a circle about the axis of rotation.

[0035] Preferably, the second leg is located on a radial line passing through the axis of rotation and is perpendicular to the base side.

[0036] The angle between the leg and the curved base side is formed between the leg and the tangent, which abuts against the base side at the intersection of the leg and the base side.

[0037] Because the cross-sectional surface of the ground teeth on the rotor and / or stator tapers radially, an asymmetrical cross-sectional surface is obtained. There is no radial line that is symmetrical about the cross-sectional surface with respect to its mirror image. The cross-sectional surface of the ground teeth on the rotor and / or stator has steep flanks (i.e., legs that form an angle of 85°–95° with the base surface) and flat flanks.

[0038] Preferably, the rotor grinding surface and / or the stator grinding surface have a plurality of grinding teeth that are spaced at the same distance, particularly in the circumferential direction.

[0039] The tapering of the cross-sectional surface causes the rotor and stator to be very close to each other only on a relatively small portion of the circumferential surface. Therefore, the shear force between the rotor and stator is less than that in a colloid mill with a conventional rectangular grinding tooth cross-sectional surface.

[0040] Therefore, the material is heated less.

[0041] At the same time, the steep flanks ensure effective crushing.

[0042] The rotor and stator can be designed such that the rotor grinding surface and the stator grinding surface are substantially cylindrical or conical. The colloid mill can be designed such that the axis of rotation is arranged vertically during operation and can flow from top to bottom through the colloid mill.

[0043] The radius of the grinding gap between the rotor and the stator can be increased in the flow direction (especially downwards).

[0044] One or more grinding teeth may be designed as ribs and extend or be inclined in the axial direction along the stator grinding surface and / or rotor grinding surface on the shortest path.

[0045] In the case of inclined grinding teeth, the longitudinal extension of the rib forms an angle of not equal to 90° with the circumference perpendicular to the axis of rotation or with the direction of rotation.

[0046] Inclined grinding teeth facilitate material transport through the colloid mill.

[0047] A colloid mill can have sections with two or more grinding teeth, each section having a different inclination in the axial direction. The degree and / or direction of inclination can change from one section to the next.

[0048] On the circumference in the axial direction, a colloid mill may have a section with two or more grinding teeth, which have different dimensions and / or densities.

[0049] Preferably, the colloid mill has one, two, or three parts.

[0050] On the material inlet side, the colloid mill may have an axial portion, wherein the rotor does not have a circumferentially closed rotor grinding surface. In this region, the rotor surface may have arms pointing in the axial direction, for example, three or more arms, on which grinding teeth may be located.

[0051] Preferably, the colloid mill has a drive device that ensures a rotor speed of 2500 rpm to 3500 rpm, particularly 2900 rpm to 3000 rpm, at a frequency of 50 Hz.

[0052] In an advantageous embodiment, the cross-sectional surface of at least one grinding tooth is formed into a polygon, particularly a quadrilateral, having a longer base side extending in the circumferential direction and a shorter base side parallel to the first base side.

[0053] In this case, the cross-sectional surface is approximately trapezoidal.

[0054] The shorter base side is preferably located on a circle about the axis of rotation, and therefore points in the radial direction. The shorter base side of the cross-sectional surface lies on the shear surface of the grinding tooth.

[0055] The shorter base side is at a distance from the bottom line, which forms a circle around the axis of rotation, and the larger base side is located on the bottom line.

[0056] Alternatively or otherwise, the cross-sectional surface of at least one grinding tooth forms a polygon, particularly a triangle, the apex of which points toward the opposite grinding surface or a grinding surface arranged opposite to it. The apex of the triangle is located on the shear edge of the grinding tooth.

[0057] The apex is the corner of a polygon, where adjacent sides form an angle of less than or equal to 90°.

[0058] The triangle can be a right triangle, where the hypotenuse forms a flat flank on the cross-sectional surface of the grinding tooth.

[0059] Alternatively, other cross-sectional surfaces may be considered, particularly cross-sectional surfaces having a longer base side and a shorter base side and located on the shear surface (the longer base side is located on the bottom line of the grinding surface, and the shorter base is spaced apart from the longer base side and extends particularly parallel to the longer base side) or cross-sectional surfaces having a tip pointing in the radial direction.

[0060] The cross-sectional surface can be, for example, pentagonal or polygonal. The flatter sidewalls of the grinding teeth can be inclined.

[0061] At least one grinding tooth on the rotor grinding surface and / or stator grinding surface is preferably designed as a rib, wherein the cross-sectional surface maintains a constant dimension along its longitudinal direction.

[0062] Alternatively or otherwise, the cross-sectional surfaces may vary their dimensions along the flow direction (e.g., in the direction from the material inlet to the product outlet).

[0063] In the flow direction, the ribs then gradually occupy the space between the stator and the rotor, causing the channel area for the material to decrease in the flow direction in a plane perpendicular to the axis of rotation.

[0064] The shortest distance between the rotor grinding surface and the stator grinding surface can be in the range of 0.05mm to 1.2mm.

[0065] The shortest distance can be considered as the width of the grinding gap between the rotor and the stator.

[0066] The shortest distance between the rotor grinding surface and the stator grinding surface is located between the shear surface or shear edge of the rotor and the shear surface or shear edge of the stator.

[0067] Preferably, the shortest distance between the rotor grinding surface and the stator grinding surface lies in a plane perpendicular to the axis of rotation between the shorter base side of the quadrilateral cross-sectional surface or the apex of the triangular cross-sectional surface on the grinding teeth of the stator grinding surface and the shorter base side of the quadrilateral cross-sectional surface or the apex of the triangular cross-sectional surface on the grinding teeth of the rotor grinding surface.

[0068] The shortest distance can remain constant in the axial direction or change in the axial direction (e.g., decrease).

[0069] The shortest distance can be kept constant during machining. The grinding clearance can be variable, for example, through the mutual axial displacement of the rotor and stator.

[0070] In the case of a colloid mill, the cross-sectional surfaces of the grinding teeth on the rotor grinding surface and the stator grinding surface have a shorter base side extending parallel to the longer base side located on the bottom line, and the shear surface rate (SSR) value can be less than 0.25, and particularly less than 0.07.

[0071] The value of shear surface rate (SSR) represents the product of the proportion of the shorter base side of the cross-sectional surface of the grinding teeth on the rotor grinding surface in the circumference of the circle formed by the bottom line of the rotor grinding surface around the axis of rotation and the proportion of the shorter base side of the cross-sectional surface of the grinding teeth on the stator in the circumference of the circle formed by the bottom line of the stator grinding surface around the axis of rotation.

[0072] The shear surface rate (SSR) of all rotors and stators with radially pointing shear surfaces can be calculated. Their grinding teeth have a cross-sectional surface with a base side spaced from the bottom line and pointing radially.

[0073] The bottom line connects to the cross-sectional surface of the grinding tooth. For example, the longer base side of the cross-sectional quadrilateral lies on the circle formed by the bottom line.

[0074] The smaller the shear surface rate (SSR) value, the smaller the area where shearing occurs in the colloid mill, and the less the material is heated.

[0075] The colloid mill can have a housing fixedly connected to the stator. Alternatively, the colloid mill can have a housing in which the stator and housing are not integrally manufactured and the stator is particularly replaceable. The stator can be formed as an inner stator housing that can be removed from and replaced by the housing. After wear, the stator can, for example, be removed and replaced by a new or refurbished stator in the same housing.

[0076] Alternatively, the rotor can be configured as a replaceable component. For this purpose, ground surfaces can be formed on a rotor housing, which can be replaceably fastened to the rotor shaft. Alternatively, the rotor can be disassembled and replaced together with the shaft.

[0077] The object of the present invention is also achieved by a system for processing food substances (preferably containing fatty substances). This system comprises a colloid mill as described above. The colloid mill is particularly arranged upstream of a ball mill, and / or particularly arranged downstream of a mixer.

[0078] The system may include a refining mill, which may be positioned before or after the colloid mill in the process direction.

[0079] The object of the present invention is also achieved by a method for reducing the particle size of particles suspended in a first liquid and / or the droplet size of a second liquid emulsified in the first liquid in a colloid mill as described above, wherein the first liquid is in particular a fatty substance.

[0080] In this process, in order to form a suspension or emulsion, the material is guided from the first axial end of the colloid mill to the second axial end of the colloid mill along the space between the rotor grinding surface and the stator grinding surface.

[0081] The temperature rise of the material is less than 40°C along the path through the colloid mill.

[0082] In a plane perpendicular to the axis of rotation, the area between the cross-sectional surfaces of two circumferentially adjacent grinding teeth on the stator grinding surface and / or rotor grinding surface can provide space for the cross-sectional surfaces of 3-10 particles and / or droplets added to the colloid mill.

[0083] The object of the present invention is also achieved by a rotor for a colloid mill as described above, wherein the rotor has a rotor grinding surface to be faced with the stator.

[0084] The rotor grinding surface has at least one grinding tooth with a shear surface and / or shear edge, the cross-sectional surface of which tapers radially toward the stator grinding surface opposite it in the installed state within a plane perpendicular to the axis of rotation.

[0085] The cross-sectional surface has a first leg, preferably a straight first leg, which is adjacent to a base side extending circumferentially from the cross-sectional surface. The first leg points in the direction of rotation of the rotor, which is provided in the mounted state. The first leg forms an angle of 80°-100°, preferably 85°-95°, with the base side.

[0086] The object of the invention is also achieved by a stator for a colloid mill as described above, wherein the stator has a stator grinding surface to be faced by the rotor. This stator grinding surface has at least one grinding tooth with a shear surface and / or shear edge, the cross-sectional surface of which tapers radially in a plane perpendicular to the axis of rotation toward the rotor grinding surface opposite it in the mounted state. This cross-sectional surface has a second leg, preferably a straight second leg, which abuts a circumferentially extending base side of the cross-sectional surface and points in a direction opposite to the rotational direction of the rotor provided in the mounted state. The second leg forms an angle of 80°-100°, preferably 85°-95°, with the base side. Attached Figure Description

[0087] The present invention will now be explained with reference to a description of specific embodiments and corresponding drawings.

[0088] In the attached diagram:

[0089] Figure 1 A schematic diagram showing a detailed view of a first example of a stator and rotor in plan view;

[0090] Figure 2 A schematic diagram showing a detailed view of a second example of a stator and rotor positioned relative to each other in a plan view;

[0091] Figure 3 A schematic diagram showing detailed views of various configurations of grinding teeth for stators and rotors in plan view;

[0092] Figures 4a-4e A schematic diagram showing a further example of the stator and rotor in plan view;

[0093] Figures 5a-5c A schematic diagram showing a further example of the stator and rotor in plan view;

[0094] Figure 6a The results of flow rate calculations for two exemplary curves are shown;

[0095] Figure 6b Showing according to Figure 6a The results of shear rate calculations for an exemplary profile curve;

[0096] Figure 7a An example of a rotor is shown in perspective;

[0097] Figure 7b An example of a stator is shown in perspective;

[0098] Figure 8 A schematic diagram of the system is shown. Detailed Implementation

[0099] Figure 1 A schematic diagram showing a detailed view of a first example of rotor 1 and stator 2 in plan view. Rotor 1 and stator 2 are coaxially arranged inside the other, with rotor 1 arranged inside stator 2 and rotating against stator 2 in the direction of rotation 15.

[0100] The rotor 1 has a rotor grinding surface 3 facing the stator 2, and the stator 2 has a stator grinding surface 4 facing the rotor 1.

[0101] As shown in the figure, the rotor grinding surface 3 has grinding teeth 5a with shear surfaces 6. The cross-sectional surface 8a of the grinding teeth tapers radially toward the opposite stator grinding surface 4 in a plane perpendicular to the rotation axis D. The cross-sectional surface 8a has a straight first leg 14a, which abuts the base side 11a of the cross-sectional surface 8a extending in the circumferential direction 15 and points toward the rotation direction 15 of the rotor 1. The first leg 14a and the base side 11a form an angle α of 90°.

[0102] The cross-sectional surfaces 8a of the grinding teeth 5a on the rotor 1 each form a quadrilateral. They have a longer base side 11a extending in the circumferential direction and a shorter base side 12a parallel to the first base side and located on the shear surface 6 of the corresponding grinding tooth 5a.

[0103] The stator grinding surface 4 has grinding teeth 5b with shearing edges 7, and the cross-sectional surface 8b of the grinding teeth tapers toward the opposite rotor grinding surface 3 in the radial direction Rb in a plane perpendicular to the rotation axis D.

[0104] The cross-sectional surface 8b has a straight second leg 14b, which is adjacent to the circumferentially extending base side 11b of the cross-sectional surface 8b. The second leg 14b points in the opposite direction to the rotation direction 15 of the rotor 1. The second leg 14b and the base side 11b form an angle β of 90°.

[0105] The cross-sectional surface 8b of the grinding teeth 5b on the stator each forms a triangle, the tip of which points in the radial direction Rb and forms a shear edge 7.

[0106] Figure 2 A schematic diagram showing a detailed view of a second example of a stator 2 and a rotor 1 in two different positions relative to each other, in a plan view, wherein the rotor 1 has been further moved in the rotational direction in the second image.

[0107] The material to be processed 102 is located between the rotor 1 and the stator 2.

[0108] The rotor 1 has grinding teeth 5a, and the stator has grinding teeth 5b. In both cases, the cross-sectional surface of the grinding teeth is quadrilateral.

[0109] The shortest distance 17 between the rotor grinding surface 3 and the stator grinding surface 4 is the distance 17 between the grinding teeth when the grinding teeth 5a and 5b are precisely aligned, as shown in the second image. Because the cross-sectional surfaces 8a and 8b taper radially, the shear gap defined by the area in which the material 102 must pass through the shortest distance 17 occupies only a relatively short proportion of the length of the entire circumference.

[0110] The value of shear surface rate (SSR) represents the product of the proportion of the shorter base side 12a of the cross-sectional surface 8a of the grinding tooth 5a on the rotor grinding surface 3 in the circumference of the circle formed by the bottom line 16a of the rotor grinding surface 3 around the axis of rotation and the proportion of the shorter base side 12b of the cross-sectional surface 8b of the grinding tooth 5b on the stator 2 in the circumference of the circle formed by the bottom line 16b of the stator grinding surface 4 around the axis of rotation.

[0111] If the grinding teeth 5a and 5b are evenly distributed on the circumference, then in each case it is sufficient to consider only one grinding tooth 5a, 5b and lengths s1+b1 and s2+b2, where lengths s1+b1 and s2+b2 each describe the distance of the steep flanks, and s1 and s2 are the lengths of the short base sides 12a and 12b. In this case, the shear surface rate is s1 / (s1+b1)*s2 / (s2+b2).

[0112] Based on the shear surface rate (SSR), losses and temperature rise can be calculated.

[0113] Loss is

[0114]

[0115] The shear rate is calculated as follows:

[0116]

[0117] And assume the volume in the grinding gap is

[0118] .

[0119] Instead, this led to

[0120]

[0121] Temperature rise can be determined by the following:

[0122] .

[0123] In this case, n is the rotational speed in rpm, and R1 is the inner radius of the rotor in meters (see...). Figure 5c R2 is the outer radius of the rotor in meters (see...). Figure 5c ), h is the shortest distance 17, is the flow rate in kg / h, η is the viscosity of the substance, c p It is the specific heat capacity expressed in J / kg / K.

[0124] Therefore, the temperature rise depends linearly on the shear surface rate.

[0125] Figure 3A schematic diagram showing detailed views of various configurations for the stator and rotor in plan view, wherein for each configuration, the stator 2 is shown in the upper half and the rotor 1 is shown in the lower half.

[0126] Structures 1 and 2 show the conventional cross-sectional surface of grinding teeth that are not radially tapered. The corresponding values ​​for the shear surface rate (SSR) are large.

[0127] The more radially tapered the cross-sectional surfaces 8a and 8b, the smaller the value of the shear surface rate (SSR) becomes.

[0128] Figures 4a-4e A schematic diagram showing a further example of a stator 2 and a rotor 1 arranged coaxially within the stator 2 in a plan view.

[0129] The example has different distances 18 between bottom lines 16a and 16b, different shortest distances 17 between opposite grinding teeth 5a and 5b, and different numbers of grinding teeth 5a and 5b in each case.

[0130] According to Figure 4b In the example, grinding teeth 5a and 5b are adjacent to each other without any distance in each case.

[0131] according to Figure 4c The grinding teeth 5a and 5b are relatively large distances 19a and 19b from each other in the circumferential direction.

[0132] according to Figure 4d Only the legs 14a of the grinding teeth 5a of rotor 1 form steep flanks.

[0133] according to Figure 4e The grinding teeth 5a and 5b of stator 2 and rotor 1 each have triangular cross-sectional surfaces 8a and 8b, with their tips 9 pointing to the grinding surfaces 3 and 4 respectively.

[0134] Figures 5a-5c A schematic diagram showing a further example of stator 2 and rotor 1 in plan view.

[0135] The distance between bottom lines 16a and 16b is 18 (see...) Figure 5a The number of grinding teeth 5a on rotor 1 and the radial extension 20 of the rotor grinding teeth 5a are selected such that the region 21 between the cross-sectional surfaces 8a of two circumferentially adjacent grinding teeth 5a provides space for the cross-sectional surfaces 100 of 3 to 10 particles 101 in a plane perpendicular to the axis of rotation (as shown).

[0136] The cross-sectional surface 8a of the ground teeth 5a of the rotor preferably comprises less than 50% of an annulus having an inner radius R1 and an outer radius R2, wherein the inner radius R1 is the distance of the bottom line 16a from the axis of rotation, and the outer radius R2 is the distance of the shorter base side 12a from the axis of rotation, i.e., corresponding to the outer radius of the rotor 1 (see...). Figure 5c ).

[0137] The cross-sectional surface 8b preferably comprises less than 50% of an annulus having an inner radius R3 and an outer radius R4, wherein the inner radius R3 is the distance of the shorter base side 12b from the axis of rotation, thus corresponding to the inner radius of the stator 2, and the outer radius R4 is the distance of the bottom line 16b from the axis of rotation (see...). Figure 5a ).

[0138] Figure 6a The results of two exemplary curve calculations for the flow rate of material 102 between grinding teeth 5a and 5b are shown. The left image corresponds to... Figure 3 Construction 3; the right image corresponds to Figure 3 Construction 2.

[0139] The flow velocities represented by different colors were obtained through computer simulations of fluid dynamics based on the Herschel-Bulkley model.

[0140] It was found that using the curve according to the invention (left image) and a smaller SSR value than the conventional curve (right image) achieved a larger area with higher speed. This indicates higher mass transfer and better pulverization effect.

[0141] Figure 6b Showing according to Figure 6a The exemplary curve is the result of the shear rate calculation for the material 102 between grinding teeth 5a and 5b.

[0142] The shear rates, represented by different colors, were obtained through computer simulations of fluid dynamics based on the Herschel-Bulkley model.

[0143] It was found that a smaller region with a higher shear rate was achieved using the curve according to the invention (left image) and a smaller SSR value than the conventional curve (right image). This indicates that less heating is required for material 102.

[0144] Figure 7a An example of rotor 1 is shown in perspective.

[0145] Rotor 1 has a basic conical shape.

[0146] The grinding teeth 5a on the rotor grinding surface 3 are formed as ribs 13, which form an angle of less than 90° with the rotation direction 15. And therefore tilted.

[0147] Figure 7b An example of stator 2 is shown in perspective.

[0148] The stator grinding surface 4 has a basic conical shape.

[0149] The grinding tooth 5b is formed as a rib 13, which forms an angle of less than 90° with the rotation direction 15. .

[0150] Table 1 below shows the results of pulverizing peanuts using a conventional colloid mill, which is equipped with a colloid mill according to... Figure 3 The grinding teeth are structure 3. Peanuts have a high fat content (approximately 49%), so no fat needs to be added.

[0151]

[0152] Table 1

[0153] The shortest distance 17 or grinding clearance (referred to as "clearance" here), flow rate in kg / h, power in kW, material temperature at the material inlet ("inlet") and material temperature at the product outlet ("outlet") in °C, the difference between them, and energy consumption in kW / t.

[0154] Depending on the grinding clearance, the material is heated to over 40°C.

[0155] Table 2 below shows the results of pulverizing peanuts using the colloid mill according to the present invention.

[0156]

[0157] Table 2

[0158] The same values ​​as in Table 1 are listed, and the reduction in temperature difference compared to a conventional colloid mill with the same grinding clearance is also listed.

[0159] It is clear that not only is there less heating, but there is also a higher flow rate and lower energy consumption.

[0160] Figure 8 A schematic diagram of a system 70 is shown, comprising a mixer 60, a colloid mill 40, and a ball mill 50.

Claims

1. A colloid mill, said colloid mill being used to reduce the particle size of particles (101) suspended in a first liquid and / or the droplet size of a second liquid emulsified in the first liquid, The colloid mill has at least one rotor (1) and at least one stator (2), the at least one rotor and the at least one stator being coaxially arranged inside the other. The at least one rotor (1) has a rotor grinding surface (3) facing or to be facing the stator (2), and the at least one stator (2) has a stator grinding surface (4) facing or to be facing the rotor (1). Its features are, The rotor grinding surface (3) has at least one grinding tooth (5a, 5b) with a shear surface (6) and / or a shear edge (7), wherein the cross-sectional surface (8a) of the grinding tooth (5a, 5b) tapers toward the opposite stator grinding surface (4) in a radial direction (R) in a plane perpendicular to the axis of rotation (D), wherein the cross-sectional surface (8a) has a first leg (14a) adjacent to the circumferentially extending base side (11a) of the cross-sectional surface (8a), the first leg pointing toward the rotation direction (15) of the rotor (1), and the first leg forming an angle (α) of 80°-100° with the base side (11a). And / or The stator grinding surface (4) has at least one grinding tooth (5a, 5b) with a shear surface (6) and / or a shear edge (7), the cross-sectional surface (8b) of the grinding tooth tapering radially (R) toward the opposite rotor grinding surface (3) in a plane perpendicular to the axis of rotation (D), wherein the cross-sectional surface (8b) has a second leg (14b) adjacent to the circumferentially extending base side (11b) of the cross-sectional surface (8b), wherein the second leg (14b) points in the opposite direction to the rotation direction (15) of the rotor (1), and the second leg (14b) forms an angle (β) of 80°-100° with the base side (11b). Wherein, at least one of the at least one grinding tooth (5a, 5b) of the rotor grinding surface (3) and at least one grinding tooth (5a, 5b) of the stator grinding surface (4) forms a triangle, the tip (9) of the triangle pointing to the opposite grinding surface (3, 4) or the grinding surface (3, 4) arranged opposite to it.

2. The colloid mill according to claim 1, wherein the grinding teeth (5a, 5b) are formed as ribs (13) extending longitudinally with a constant large cross-sectional surface (8a, 8b).

3. The colloid mill according to claim 1 or 2, wherein the shortest distance (17) between the rotor grinding surface (3) and the stator grinding surface (4) is between 0.05 mm and 1.2 mm.

4. The colloid mill according to claim 1, wherein the value of the shear surface rate (SSR) is less than 0.07, wherein the value of the shear surface rate (SSR) represents the product of the proportion of the shorter base side (12a) of the cross-sectional surface (8a) of the grinding teeth (5a) of the rotor grinding surface (3) in the circumference of the circle formed by the bottom of the rotor grinding surface (3) around the axis of rotation and the proportion of the shorter base side (12b) of the cross-sectional surface (8b) of the grinding teeth (5b) on the stator (2) in the circumference of the circle formed by the bottom of the stator grinding surface (4) around the axis of rotation.

5. The colloid mill according to claim 1 or 2, wherein the colloid mill has a housing, and the stator (2) and the housing are not integrally manufactured, such that the stator (2) is replaceable.

6. The colloid mill according to claim 1, wherein the first liquid is an aliphatic substance.

7. The colloid mill according to claim 1, wherein the rotor (1) is arranged within the stator (2) or can be attached to the stator.

8. The colloid mill according to claim 1, wherein the colloid mill has at least one material inlet on a first axial side for introducing particles, liquids, suspensions and / or emulsions, and at least one product outlet on a second axial side for discharging the suspension or emulsion.

9. The colloid mill according to claim 1, wherein the first leg is a straight first leg.

10. The colloid mill according to claim 1, wherein the first leg forms an angle (α) of 85°-95° ​​with the base side (11a).

11. The colloid mill according to claim 1, wherein the first leg is located on a radial line passing through the axis of rotation.

12. The colloid mill according to claim 1, wherein the second leg is a straight second leg.

13. The colloid mill according to claim 1, wherein the second leg (14b) forms an angle (β) of 85°-95° ​​with the base side (11b).

14. The colloid mill according to claim 1, wherein the second leg is located on a radial line passing through the axis of rotation.

15. A system for processing food substances, said system comprising a colloid mill (40) according to any one of claims 1 to 14.

16. The system of claim 15, wherein the food substance contains a fatty base substance.

17. The system of claim 15, wherein the colloid mill is arranged upstream of the ball mill (50) and / or downstream of the mixer (60).

18. A method for reducing the particle size of particles suspended in a first liquid and / or the droplet size of a second liquid emulsified in the first liquid in a colloid mill according to any one of claims 1 to 14. In order to form a suspension or emulsion, the material is guided from the first axial end of the colloid mill to the second axial end of the colloid mill along the space between the stator grinding surface and the rotor grinding surface. The temperature of the material rises by less than 40°C as it passes through the colloid mill.

19. The method according to claim 18, wherein in a plane perpendicular to the axis of rotation, the area between the cross-sectional surfaces of two circumferentially adjacent grinding teeth (5a, 5b) on the stator grinding surface (4) and / or the rotor grinding surface (3) provides space for the cross-sectional surfaces (100) of 3 to 10 particles (101) and / or droplets.

20. The method of claim 18, wherein the first liquid is a fatty substance.

21. A rotor for a colloid mill according to any one of claims 1 to 14, wherein the rotor (1) has a rotor grinding surface (3) to be oriented toward the stator (2). Furthermore, the rotor grinding surface (3) has at least one grinding tooth (5a) with a shear surface (6) and / or a shear edge (7), the cross-sectional surface (8a) of the grinding tooth tapers toward the opposite stator grinding surface (4) in the radial direction (R) in a plane perpendicular to the axis of rotation (D), the cross-sectional surface (8a) has a first leg (14a) adjacent to the base side (11a) of the cross-sectional surface (8a) extending in the circumferential direction, the first leg pointing toward the rotation direction (15) of the rotor (1) and forming an angle (α) of 85°-95° ​​with the base side (11a).

22. The rotor of claim 21, wherein the first leg is a straight first leg.

23. A stator for a colloid mill according to any one of claims 1 to 14, wherein the stator (2) has a stator grinding surface (4) to face a rotor (1), and wherein the stator grinding surface (4) has at least one grinding tooth (5b) with a shear surface (6) and / or a shear edge (7), the cross-sectional surface (8b) of the grinding tooth tapering toward the opposite rotor grinding surface (3) in the radial direction (R) in a plane perpendicular to the axis of rotation (D), the cross-sectional surface (8b) having a second leg (14b) adjacent to the base side (11b) of the cross-sectional surface (8b) extending in the circumferential direction, the second leg pointing in a direction opposite to the rotation direction (15) of the rotor (1) and forming an angle (β) of 85°-95° ​​with the base side (11b).

24. The stator according to claim 23, wherein the second leg is a straight second leg.

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