FI94030B - Device, particularly for processing creams and pastes - Google Patents

Description

94030

Device for handling pastes and pastes in particular

The present invention relates to an apparatus according to the preamble of claim 1, in particular for processing pastes and pastes, preferably for mixing and / or grinding them.

Such a device generally comprises a drum arranged in the frame, inside which at least two concentric rotating rings with collision barriers are mounted substantially parallel to its central axis, at least one of which is arranged to rotate in the opposite direction to the other ring (s). The device further comprises actuators for the rotatable frames 15 connected to the power sources, as well as supply and discharge means for the substance to be treated.

Different equipment is used for the treatment of the material, depending on the hardness of the material to be treated, the viscosity of the material, the particle size, etc. Dry powders or clearly liquid mixtures are known to be easy to mix and / or grind. Mixtures called pastes, pastes, etc., on the other hand, are difficult to mix because of their high viscosity and intrinsic cohesion, i.e., size-25 stability. A typical mixer for such materials is a double z-mixer in which two Z-shaped mixer members rotate in opposite directions. One application is the so-called A beef mixer in which a conical vessel rotates along the edges of a mixing screw. Screw mixers have a low mixing speed and high mixing forces due to the high viscosity of the material. However, the effect obtained by such mixing is in no way proportional to the conducted power of the pulp, which is almost all converted into heat.

35 A large number of grinders are also known which can grind both dry and liquid materials. Typically, material is removed from these grinders through a classifier, in which case the material must be a dry powder or, on the other hand, a liquid with a relatively low solids content.

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In addition to the above, toothpastes and other pastes are also mixed in a mill, which has perimeters rotating in different directions with collision barriers (so-called pin mill or pin grinder) and which is also widely used e.g. for grinding and mixing grain and mash as well as various 5 feeds. In the pin grinder, the material to be handed is ejected from one collision barrier until the material leaves the device after a residence time of about 0.01 to 0.1 seconds.

10 There are several drawbacks to the prior art. Thus, in mills and mixers such as the one described, the problem is e.g. manual.

removal of the material. The problem is greatest when the material to be treated is a paste, putty or similar mixture of solid and liquid, in which the proportion of solid 15 is more than half the mass or in which the viscosity of the liquid is high. Although numerous pin grinder patents describe various material removal arrangements, they do not address the difficulties associated with handling putty-like materials. In most cases, please describe that the product is removed from the center of the conical base.

Thus, DD Patent Publication No. 136579 discloses a solution in which the material automatically falls from the vertical surfaces of the circumference to the bottom from which it is conveyed.

: 5 In the device of the Estonian Desintegrator Group, pasty substances have been removed by means of a belt conveyor around the device. The problem has been the material flown aside from said raw material belt, which gets on the belt guides and the material flown on the belt wears the belt.

The object of the present invention is to eliminate the drawbacks associated with the prior art and to provide a new device, in particular for treating pastes and pastes, from which the treated material can be easily removed. It is also an object of the invention to provide a device by means of which air is obtained

removed from the viscous material after grinding and / or mixing. I

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3,94030

The invention uses a device having the structure mentioned in the introduction. The device thus has concentric circumferences rotating in opposite directions, from which the material to be treated is ejected out by the centrifugal force onto the inner surface of the drum 5 surrounding the circumferences (pin grinder). The invention is based on the idea that at least one of the rotors of the device, i.e. the grinding frames, is provided with discharge vanes which rotate with the rotor. The discharge vanes are arranged in a position substantially deviating from the horizontal plane and their outer edges are located close to the inner casing of the drum 10 and are directed towards this. An outlet opening is formed flush with the outlet vanes in the wall of the drum, and an outlet pipe is attached as an extension. As the rotor rotates, the material ejected into the inner jacket then scratches in front of the discharge vanes and exits through the discharge pipe.

More specifically, the device according to the invention is essentially characterized by what is set forth in the characterizing part of claim 1.

According to a preferred embodiment of the invention, the discharge vanes are substantially parallel to the radius of the rotor frames, preferably there are two or more vanes. In principle, the device according to the invention also operates with one discharge wing, as long as the circumference is balanced. The vanes are preferably fitted to a rotor ring with an elongated washer.

The above-mentioned outlet pipe is preferably mounted parallel to the tangent of the outer casing of the drum. There may be several outlets and outlet pipes.

30 According to one embodiment, the discharge vanes are convex in the circumferential direction of rotation. Alternatively, they may also be substantially planar. Most preferably, however, they are always in a substantially vertical position.

In the device according to the invention, a clearance is left between the outer edge of each discharge vane and the inner casing of the drum, which is preferably larger than the particle size of the largest particle 4 94030 in order to avoid cutting and unnecessary wear.

When the device according to the invention is used, all the material which snaps onto the shell jacket is scraped in front of the discharge vanes 5 and leaves the opening in the jacket even at a considerable radial speed according to the power of the rotor.

The advantage of the structure is that the shell jacket does not wear out when the permanent layer of material in it protects the jacket. Due to the removal of the product, no additional moving part has been constructed in the device-10 and only the outer edge of the discharge wings wears when the discharge wings are radial.

The specific impulse received by the pulp can be made very large in the device 15 according to the invention. You see, high power is applied to a small amount of material at a time. This breaks down cellular structures and the surface of the material, as well as providing intimate contact between the different ingredients in the paste, breaking up pigment deposits, and so on.

20

It should be noted that the operation of the device according to the invention requires that the rotors rotate so rapidly that the device is not filled and that the centrifugal force clearly exceeds the viscous and adhesive forces that the material to be mixed has against the walls of the device. Depending on the size, such twin or multi-rotor mixers typically rotate at speeds of 15 to 100 rpm, with the speed of rotation being sufficient to keep the device operating at a consistently low operating rate. The device operates with respect to the material to be mixed and / or ground in a continuous phase, i.e. only a part of the volume of the device is filled with the material.

As mentioned above, in the discontinuous phase mixing 35, the mixing of air or ambient gas into the pulp is always a potential problem. In the device according to the invention, this phenomenon can be avoided, if desired, by causing the material to be treated to collide with the receiving wall at a relatively higher speed, whereby air is again removed from the pulp. The device achieves a similar result as, for example, vibrating concrete.

5

In a preferred embodiment of the invention, in order to remove the air still present in the pulp or paste leaving the pin mill, the material is conveyed through a screw conveyor with a helix screw (i.e. a helical mixing screw, an open screw). Due to its structure, the helix screw mixes the pulp with poor efficiency, which has surprisingly been found to be advantageous in terms of deaeration. Thus, in this embodiment, during the continuous mixing of the helix screw of the screw conveyor, it is possible to remove air through the open central part 15 of the screw. The efficiency of the air removal can be further improved by raising the temperature of the pulp or paste or by subjecting it to a vacuum in a screw mixer. For the latter purpose, any conventional vacuum pump can be used, in which case the preferred pressure of the screw conveyor (and the grinding unit) is about 0.01 to 0.5 bar, in particular about 0.05 to 0.15 bar, e.g. about 0.1 bar.

The invention will now be examined in more detail with the aid of the accompanying drawing. Fig. 1 shows a side view of the device according to the invention in cross-section and Fig. 2 a top view of the device.

Figure 3 is a partially sectioned top view of a device according to a preferred embodiment of the invention, provided with a screw conveyor for handling the material to be removed.

The pin grinder according to the invention comprises a steel-structured, preferably rectangular, frame frame structure 1, 35, the corners of which have legs on which the frame is placed on the base. At one end of the frame frame 1 there is a fixed engine bed (not shown) which supports two electric motors 6 94030 fixed to the engine bed so that their shafts are in a vertical position. A grinding section 2 is mounted on the frame 1, which comprises a low but wide drum 3. At the feed opening formed in the upper surface of the drum 3, a feed hopper 4 to be treated is placed, which may be fixed to the upper surface of the drum 3 or separately fixed.

Inside the drum 3, two grinding frames 5 and 6, 10 are mounted, the rotating planar circumferential plates of which are provided with pins 7 perpendicular to the direction of rotation of the frames. The grinding frames 5 and 6 are mounted concentric on the same shaft. In order to rotate the grinding rings 5 and 6, they are connected by means of V-belts (not shown) and a drive shaft and a wheel 8 to the drive shafts of the above-mentioned motors so that the rings 5 and 6 can be rotated in opposite directions.

Arranged on the side of the drum 3 is a substantially horizontal out-20 top tube 9, which is attached to the opening formed in the drum 3. As shown in Fig. 2, the outlet pipe is parallel to the tangent of the outer jacket of the drum 3.

The diameter of the lower plate of the lower grinding ring 6 is at least somewhat larger than the diameter of the upper grinding ring plate 5. Arranged on the extended edge of the lower plate 6 are outlet vanes 10 rotating with the lower plate, which are mounted in a substantially vertical position. In the case of the exemplary embodiment, the discharge vanes 10 are made of metal, but they can also be 30 ceramic substances or even hard rubber. The discharge vanes 10 extend somewhat below the lower circumferential plate 6. The purpose of this solution is to ensure that the material on the inner surface of the jacket, which has had some drainage due to gravity, can also be scraped.

The diameter of the drum 3 and the grinding ring 6 are chosen so that there is at least a gap of at least the largest particle size between the vertical inner surface of the drum 3 and the outer edge of the outer grinding ring.

In the embodiment according to the figures, the wing 10 is substantially planar. The axis parallel to the plane of the wing is parallel to the radius of the drum 3.

Alternatively, the wing 10 can be shaped concave against the direction of rotation, whereby its shape and function always correspond approximately to e.g. the plow of a snow truck.

The pin grinder according to the invention operates as follows: The grinding rings 5 and 6 are rotated in different directions by means of electric motors. The material to be ground is fed through a hopper 4, whereby the material hits the rotating base plate and is ejected outwards by centrifugal force until it encounters the first impedance 7. From this impedance the material is ejected into the next impedance and from there until the material into the drum 20. Any material that has been ejected or the ball is scraped in front of the discharge vanes 10 and exits the opening in the jacket and the discharge pipe 9. Under the action of the discharge vanes 9, the scraped material acquires a radial velocity which depends on the speed of the grinding frame 6.

25

Figure 3 is a partially sectioned top view of a device according to the invention with a slightly different structure. Thus, the grinding unit comprises a drum 11 in which three grinding rings 12, 13, 14, 30 with collision barriers are arranged. Two discharge vanes 16, 17 are arranged on the washer of the lowest grinding ring 14. The directions of rotation of the rings are indicated by arrows.

In the embodiment according to Fig. 3, a screw conveyor 18 is further connected to the pin milling unit 35. The screw conveyor 18 consists of an open screw (helix screw) 19 mounted by ball bearings 20 inside the open housing 21 and connected by a transmission 9 to an electric motor 23 to rotate it lengthwise. An opening (not shown) is formed in the wall 21 of the jacket, close to the base of the helix screw 19, which can be connected to a vacuum pump. The jacket 21 tapers at its left end 5 and is connected to a pipe 24, which in turn may be connected to a suitable device, e.g. a concrete mixer, for further processing of the material.

As shown in the figure, the casing 21 of the screw conveyor 18 is connected to an outlet 25 in the wall of the drum. In this embodiment, the opening covers more than 90 ° from the circumference of the drum 11 and is thus wider than the opening 9 shown in Fig. 2.

The operation of the device according to the embodiment is also shown in Figure 3. The pin grinder unit operates in basically the same way as the device described above. When encountering the collision barriers of the grinding rings 12, 13 and 14, the material fed to the grinding unit 15 is ground and mixed. It then collects on the inner surface of the wall of the drum 20, as shown by the dark width stripes of varying width marked on the inner surface in the figure. As the material is scraped from the wall by the second outlet wing 16, it is kneaded and mixed in front of the moving wing and gradually becomes more and more homogeneous. At least a portion of the air contained in the material 25 is also released during kneading. The material is then removed through an opening 25 in the wall and, under the action of the radial velocity provided by the removal vanes 16, continues in tangential motion until it impinges on the helix screw 19 and the second wall of the sheath 21. The screw 19 30 conveys the mixed and ground material through the tube 24 for any further processing that may be required.

The Helix screw conveys the pulp forward at moderately poor efficiency; it takes several turns of the screw to move the mass forward one distance corresponding to one turn of the screw. On the other hand, at the same time as the slow conveying movement, the mass is kneaded and mixed, which enhances the removal of 9,94030 of the material without air. The air released from the screw conveyor is led out of the jacket 21 from the middle part of the helix screw 19 through the above-mentioned opening. To enhance the deaeration in the grinding unit and the screw conveyor, the opening is connected to 5 vacuum pumps, which reduce the internal pressure of the device to about 0.01 ... 0.5 bar, e.g. about 0.1 bar, and pump the released air out.

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Claims (9)

An apparatus in particular for the treatment of cream and paste-like substances, comprising: - a body (1), - a drum (3; 11) arranged at the body, - at least two inside the drum (3; 11) substantially parallel to its center axis, stored concentric and rotatable rotors (5, 6; 12, 13, 14) provided with impact surfaces (7; 15) and of which at least one (5; 13) is arranged to rotate in the opposite direction with respect to the second rotor (s) (6; 12, 14), - drive means (8) for rotatable rotors (5, 6; 12, 13, 14), and 15. to the drum connected supply means (4) for feeding the material to be treated and the drum connected means (9, 10; 16, 18) for the treated material characterized in that the discharge means for the treated material comprise - discharge wings (10; 16 ) arranged on the outer edge of the at least one rotor (6; 14) mounted in a · · ': From the substantially horizontal position and awikande .J whose outer edge is near the drum (3; 11) inner sheath and is directed towards it; - a drain pipe (9; 18) located at an opening formed at the same level as the drain wings (10; 16) in the drum. (3; 11) wall, which tube is attached to the outer casing of the drum (3; 11) and is provided with a screw conveyor upstream of a helix screw (19); accumulated on the inner manifold of the drum is scraped by the front vane blades (10; 16) as the rotor (6; 14) rotates, and is discharged through the drain pipe (9; "I 18), exposing the material in the drain pipe to one of the - •• 33 aeration-promoting kneading action exerted by the helix screw 94030 Device according to claim 1, characterized in that the deflection vanes (10; 16) are substantially radially directed with respect to the rotors (5, 6; 12, 13, 14). Device according to claim 1 or 2, characterized in that the deflection wings (10; 16) are convex in the direction of rotation of the rotor (6; 14). Device according to claim 1 or 2, characterized in that the deflection wings (10; 16) are substantially flat. Device according to any of the preceding claims, characterized in that the deflection wings (10; 16) are substantially stiffened in a vertical position. 15 Apparatus according to any of the preceding claims, characterized in that the deflection vanes (10; 16) are fixed to the outer edge of a grinding rotor (6; 14) extended to the diameter. 20. ·. Device according to any of the preceding claims, characterized in that the deflection vanes (10; 16) are attached to the disc of the lower grinding rotor (6; 14), so that they extend partially to a level below the lower one. •; Surface of the disc. Device according to any one of claims 1 to 7, characterized in that the distance between the outer wings of the guide wings (10; 16) and the inner sheath of the drum (3; 11) is provided: 5: 0, in part, larger than the particle size of the largest particle. · · · · · · · · Device according to any one of the preceding claims, characterized in that the outlet pipe (9) is the pliers -: * 3S arranged in relation to the outer casing of the drum (3).