DE1918522U - ROTATING CONTAINER MILLS, IN PARTICULAR TUBE OR DRUM MILLS. - Google Patents

Description

PA 2 «616 * 5/12/65 ^

File number: O 7148/50 c GPbm

Aimelderin: Austrian-American Magnesit Aktiengesellschaft in Eadenthein / Carinthia / Austria.

Description of the rotating container mill, especially a Sohr or drum mill,

The innovation "relates to a rotating container mill, in particular Eohr or Iroramel mill, the inner wall of which has a has equilateral, polygonal basic cross-section with rounded corners and in which the grinding is carried out by the falling and rolling movement τοη hollow bodies takes place

In mills of the type mentioned, which are used to a large extent for comminuting or hot grinding of hard materials, on dry or wet roads, for grinding mixing and other uses serve, the comminution is mainly through the Schlag- und Eeibnahmuag, which the grinding media on the grist Exercise Effects · You best shredding comes through an oblique blow about; to bring about such a failure, the mill is supposed to take the grinding media with it up to its apex and then the filling up from the top

of the mills / and loosen and, in an inclined case, on the one to be married Fall down well · The frictional effect, which is decisive for fine grinding, occurs between the mill armor and the Grist · In multi-chamber mills, the Grist in the first and zireitea chamber mainly through the impact

Numerous attempts have already been made with the aim of finding out the most favorable conditions for the operation of a mill, such as the speed of the mill, formation of the armor, grinding media filling, and to gain precise knowledge about the grinding process. In particular, there are many attempts to find a connection between the power of the mills and the speed * With regard to the mill speed, the result was that this should be 72 % of the critical speed for pre-mills (= ~~ | äj / min) and 64 % of the critical speed for single mills However, since it is not possible to operate a mill, in which both pre-shredding and fine-grinding is to take place, at two different speeds, the speed for multi-chamber mills is 68 % of the critical speed, i.e. corresponding to the mean value between the Both of the values listed, chosen · '®a , however, it cannot be overlooked that this represents a compromise ellende solution has the disadvantage that the specified speed in the lalle of a mill in which the

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the greatest possible impact force of the grinding media is to be obtained, is too low and in the case of a mill for fine grinding, v / obei So it depends on the best achievable friction effect, is too high. Attempts were made to counter these disadvantages by that the armoring of the pre-grinding chamber is equipped with lifting strips, with the help of which the grinding media filling is higher up at the top of the throw was introduced. Since, however, in the previously known mills of this type, e.g. Hohrraühlen, in the Vormahlkamiaer next to If semolina is also fine, the further comminution of the fine material is only very great as a result of the then smaller work low and the fine material is practically a ballast in the antechamber, as it is only slightly changed in it.

The innovation now aims to create a rotating container mill, in particular a tube or drum mill, whose inner wall has an equilateral, polygonal green - has cross-section with rounded corners and in which the grinding by the falling and rolling movement of grinding media takes place, whereby the grinding power achieved by the beating effect depending on the ground material to be treated in a suitable, adjustable ratio to the grinding power caused by the friction. It has been found that this is the aim can then be achieved if the mill has a square basic cross-section with rounded corners and straight sides and in a manner known per se with a pile of

Grinding media is filled, the size of which is a small Brucliteil the side length of the GrundquerscJimittes of the mill. the Grinding media "preferential prices consist of Cylpepsen, i.e. pieces of Sund steel that have a diameter of about 1 to 2 cm and a length of about 3 cm. The cross section of the mill according to the The innovation is, so to speak, formed from a square with rounded corners. Preferably the rounded corners are circular formed and the roundings expediently form a quarter circle. The impact is determined by the radius or the curvature the rounding influences, namely the impact of the mill is greater, the more the curvature of the roundings or the smaller the radius of the quarter circle in relation to the diagonal of the mill cross-section. The frictional effect v / ird at a Enlargement of the impact effect smaller, with a reduction of the impact effect greater · This allows the ratio coordinated from beating effect to effect and, if necessary, also varied in sections in one and the same mill, by choosing the curvatures of the roundings to be different in sections.

Such a cross-sectional design achieves a significantly greater turbulence in the grinding media than in a mill with a round cross-section. Because the grinding media do not enter the trajectory parabola evenly as in a mill with a round cross-section, but periodically and therefore in larger quantities from the corners and thus from the point of the mill,

at which the inner surface of the mill has its greatest distance from the axis of rotation, reach the trajectory parabola, the impact energy is increased Set the diagonal of the mill cross-section according to the desired beating effect, i.e. to design or dimension the mill for any desired grinding stock in such a way that the maximum grinding capacity can be achieved Mill with a square basic cross-section with rounded corners and straight sides compared to the grinding media !! with a round mill cross-section, it is much more pulled apart and the grinding path is enlarged , a During the lifting in the mill, there are turbulence movements that have a favorable effect on the frictional effect on the grist. These movements of the grinding media, which can be referred to as internal movements, reach their maximum when the radius of the rounded corners is about 1/3 of the base square. When using a cross-section according to the innovation, the number of blows is four times the mill speed. Furthermore, as tests with a mill according to the hiring showed, a significantly higher grinding capacity is achieved with lower energy consumption

at the same time a higher penalty period was reached. Furthermore was also found that »due to the higher impact effect operated a mill according to the innovation with smaller malil bodies can be used as a mill with a round cross-section, for example.

It is possible in a simple way to convert existing mills according to the innovation · This can be achieved by lining with armor plates of suitable size and shape. In the case of a tube mill from z »B. cylindrical section succeeds in the desired basic square cross-section with rounded corners VOA uater use! armor plates of only three different shapes and sizes to manufacture.

Preferably in the mills according to the innovation Armor plates partially offset against each other, so that the dynamic momentum are balanced and one one-sided eccentric mass is avoided. This transfer in the case of a mill with several chambers, can it be done from chamber to chamber? however, the transfer can also be in take place at shorter intervals. This arrangement of the armor plates creates within the grinding chamber or grinding chambers a twist that exerts a sorting effect on the grinding media on the same side. Through a uniform Displacement of the armor around the mill can distribute the force of the blows of the grinding media filling on the grinding track and thus be divided according to the displacements and the armor plate length.

The mill according to the innovation can be used for dry grinding according to, the open and closed circuit syst em, i.e. as Continuous grinder or as a grinder with a classifier (circulating air or bucket elevator circulation), for an i-measure grinding, for grinding-mixing and for others Similar purposes can be used a greater turbulence of the liquid used and thus an additional grinding effect is achieved.

The mill according to the inflation also offers gate parts with regard to of energy consumption. In this regard, it can be mentioned that, as is known, a considerable amount of friction is caused by the frictional effect Mahlwäriae arises, which is lost for the grinding effect as such is, whereas the heat energy in the case of impact is essential is lower, so that in the mill according to the firing the losses due to frictional heat are smaller than in the known ones Mills. Finally, through microscopic experiments, it was possible to strengthen τ / earth that a mill with a square G-round cross-section with rounded corners and straight sides grinds faster and more homogeneously, and that in such a mill materials, which remain splintered for a long time in a round mill, arise almost immediately in cubic form.

Listed container mills, the inner wall of which has an equilateral, polygonal G-round cross-section already known per se. With all these known mills is

but the idea on which the innovation is based does not exist in any Wise realized · In the case of the mill according to the innovation, it is possible to achieve the effect by inducing the curvature of the roundings to combine several speeds in sections in a single mill, because, as mentioned above, with greater curvature the impact is greater and, with a weaker curvature, the impact is smaller, but the strength becomes greater. at the previously known mills, however, a change in the impact and friction effect is only through a change in speed or possible through built-in mills. Due to the innovation, a mill can therefore be designed and used for any desired regrind high efficiency using a cylindrical outer jacket to be laid out

With regard to the known mills with an angular basic cross-section, the following can be said in detail;

It is divided into chambers by partition walls Drum mill of equilateral triangular cross-section previously known, in which the partitions are placed in the corners of the drum arranged steel bars with the inclusion of spacers are lined up. Such a mill cross-section results from. a worse grinding effect from the start, because the grinding media and the Grist only fall down and hit three times per revolution of the mill and, moreover, the lall height is reduced as a result, that in the corners of the drum the Stahlstasgen arranged siacu

All other things, such a mill represents a complicated system compared to the mill according to the innovation, which has no built-in components, and there is also the fact that the steel bars arranged in the corners of the drum are subject to very great wear.

Furthermore, drum mills are already known in which rods with a polygonal cross-section are used as grinding media and in which the rotating (Eroxamel body also has a polygonal, geometrically similar to the grinding body cross-section, z. 3 · hexagonal cross-sectional shape has »mills with a pentagonal or hexagonal cross-sections already have parts approximately a rice shape, so that in such mills there is little difference compared to a mill with circular waste with regard to the grinding effect, learners are subject to in the form of rods of. polygonal cross-section trained Grinding media are subject to severe wear and tear, so that their shape does not last long, and the grinding material through abrasion this grinding media is contaminated with their material

Compared to all of these known mills, the mill according to the innovation has the surprising advantage that it can be used a square basic cross-section with straight sides and rounded corners, which are used for the grinding media and the grist are completely freely accessible without any installation

th and using conventional small grinding media, in particular Gylpepse, succeeds in achieving an excellent grinding effect.

Another known mill consists of a drum with a three-sided or multi-sided cross-section and at least one loosely located drumstick which occupies almost the entire length of the drum and which is lifted alternately as the drum rotates and falls back onto the material under its own weight . The cross section can, for example, be three-sided, heart-shaped, that is, bulged, or four-sided. Nothing is said about the use of a square basic cross-section with rounded corners and straight sides for the drum in connection with this known mill. Deviating from the straight line, i.e. the flat sides of the drum, inevitably leads to a deterioration in the effect, because bulges of this type result in a significantly lower impact effect and thus also enable the mill to be operated by changing the radius or the curvature of the rounding to adjust the effect of the corners so that the achievable results are technically of no interest *

When using flat sides and a pile of Grinding media is used in the operation of the rotating container mill according to the hiring of the grinding media at Abxrarf in the upper part The flat sides give the mill an additional movement impulse, which results in an increased beating effect,

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whereas in the lalle of a mill, which has a three-sided, heart-shaped Cross-section or another multi-sided cross-section with curved sides, the grinding media, and in particular Grinding rods, from the highest point of their path on the material to be treated, simply slide down or roll without a noteworthy effect To exert an impact »

The hiring is explained in more detail on the basis of the drawings

Fig. 1 shows a cross section through a mill according to the inflation of square basic cross-section with rounded ones Corners and straight sides,

Fig. 2 relates to a mill of square basic cross-sections with different side lengths or different Hadien or curvatures with the same diagonal in the axial direction seen,

Sig. 3 shows a tube mill according to the innovation purely schematically in axial view.

4 and 5 show two examples of a mill according to FIG the! inflation in each case in cross-section.

Fig. 6 schematically shows a particularly expedient manner of the armor plates used in three sizes with continuous mutual displacement again

In the embodiment of the mill according to the haying method shown in FIG. 1, the cylindrical jacket M is also in the axial direction In the direction of one behind the other arranged bings of armored

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plates lined · In the example shown, there is a each king group of 24 armor plates of three different formats 1, 2 and 5ί where! Formats 2 and 5 have recesses, in order to reduce the weight of the lining »The formats 3 also have radial bores to accommodate screws or other fasteners that are used to fix the ring hairs in the jacket M «

In the mill of Fig. Λ all Eingscharen the liner have the r iibrunduiigen the same Kadius, but the cross sections of the successive Hing flocks in the circumferential direction are offset. In the arrangement shown in FIG. 1, the successive cross-sections and thus the diagonals D of the mill cross-sections are each rotated by an angle <? C, in the case of 24 formats therefore by 15 ° in each case, with respect to the previous cross-section.

In the embodiment according to FIG. 2, the diagonals D of all mill cross-sections are aligned one behind the other, but in the various hinges, for example, a, b, c, d, the roundings have differently sized Hadien r _n} ru ₅ r or r -, whereby in Different strengths of impact can be achieved with the individual ring shares

In the one illustrated schematically in the axial direction in FIG The ground material is now stored through an inlet 5 first into a Yormahlkaisnier 6, then through a partition or *

Lifting wall 10 into a chamber 7 and finally through another Partition or lifting wall 10 into an end chamber 8, from which the completely ground material is discharged through an outlet 9. In the different chambers 6,? and 8 can, the armor Oe according to the special requirements with different strengths rounded cross-sections or with differently against each other be formed offset cross-sections.

The Pig. 4 and 5 show, for example, two different armor plating with the same size diagonals D. In armor 1 ', 2', J ¹ »according to FIG. 4, the radius r ^{1 of} the rounding is smaller than the radius r ^{M of} the rounding of the armor 1", 2 ^M , 3 "according to FIG. 5 · ^ ^{1 For} greater blow-out effects, the shape according to FIG. 4 will therefore be chosen.

As a result of the differently large radiuses r ¹ and r "of the roundings in the armor according to FIGS. 4 and 5, the side lengths L ¹ and L" are also the same as the cross-sections. underlying squares of different sizes, so that with the exception of the points at the ends of the diagonals D, the thickness of the armor plates 1 ¹ , 2 ', 3' with the smaller rounding radius r ¹ (Fig. 4) is greater than the thickness of the armor plates 1 ", 2", 3 "with the larger radius of curvature r" (Fig, 5) ·

Fig * 6 represents a particularly unwound in a plane advantageous distribution of armor plates in case of armor

according to Fig. 1, the mutual displacement of the armor plates takes place after a helical line. The arrow on the edge indicates the longitudinal direction of the mill.

Claims (7)

P.A.2 «616 * 12.5.65.- ·. Protection claims 1. Rotating container mill, in particular tube or drum mill, whose inner wall has an equilateral, polygonal basic cross-section with rounded corners and in which the Grinding by the falling and rolling movement of grinding media takes place, characterized in that the mill has a square Basic cross-section with rounded corners and straight sides and in a known manner with a pile is filled by grinding media, the size of which is a small fraction of the side length of the basic cross-section of the mill . 2. Mill according to claim 1, characterized in that the Grinding media consist of CyIp ep sen * 3 · Mill according to claim 1 or 2, characterized in that that the rounded corners are circular. Mm mill according to claim 3, characterized in that the rounded edges form a quarter circle 5. Mill according to one of Claims 1 to 4, characterized in that that the curvature of the rounding egg for the purpose of increasing the impact effect stronger, for the purpose of a Reduction of the impact effect is chosen to be weaker 6 · Mill according to claim 5, characterized in that in the same mill, the curvatures of the roundings in sections are different. 7. Mill according to one of claims 1 to 6, characterized in that that the lining of the mill is formed by armor plates (1, 2, 5) of three different shapes and sizes. 8. Mill according to claim 7j, characterized in that the Armor plates (1, 2, J) are offset from one another. 9. Mill according to claim 8, characterized in that the mutual displacement of armor plates (1, 2, 3) »oh one Helical line (Fig. 6) takes place. K * ntre9s: 5 <3s «UnSaHoea 'description and Sshirtjowsnt,) Ss} d! E sutetsi submitted. äi% -which "" he the where ". version of the original version from sublogos. The legal meaning <is> Ab «eichuftQ ίε? nisht g. ·; -. »-.:,« The documents originally submitted are in the <those official documents. They can be viewed free of charge. On Antrog mrot-o hier / on oyci »fofokopian oö» BImti «a» öef. UbJichao prices «delivered German Fofentom». 16 - 7.5.65 / Dr L / Kl ¹⁷ /,