MXPA99002721A - Beater bar for rotor of impact mills - Google Patents

Abstract

La invención se relaciona con una barra 1 de soplado para rotores impactores con una sección transversal longitudinal simétrica al espejo con el propósito de reversibilidad. los cuales se colocan en los rebajos 17 periféricos del rotor que ventajosamente comprende los discos 16. De acuerdo con la invención, la sección transversal de la barra 1 de soplado forma esencialmente una forma básica de doble trapecio con las bases anchas de cada trapecio como ejes 2 simétricos. La parte trasera 5 de la barra de soplado corresponde a la altura de cada trapecio y se coloca enángulos rectos respecto al eje simétrico y forma una superficie 6 de nivel sobre la altura total de la barra de soplado. La invención también especifica un rotor ventajoso para tal barra de soplado corresponde a la altura de cada trapecio y se coloca enángulos rectos respecto al eje simétrico y forma una superficie 6 de nivel sobre la altura total de la barra de soplado. La invención también específica un rotor ventajoso para tal barra de soplado.

Description

SOPHADO BAR FOR I PACTORS DESCRIPTION The invention relates to a blow bar for impactors which, for the purpose of reversibility, has a longitudinal cross section symmetrical to the mirror and has surfaces at the rear as seen in the direction of rotation of the rotor, by means of which the blow bar is supported to the rear and radially from the inside against the retaining parts provided securely on the rotor, and wherein the front part with contact surfaces for movable retaining pieces which hold the bar of blowing in coupling with the retaining pieces provided securely on the rotor. Such blow bars, which are reversible but not rotatable about their longitudinal axis, are known in various design forms. They are particularly suitable for impactor rotors which comprise a plurality of discs secured on an axis and provided circumferentially with peripheral recesses into which the blow bars are inserted. With such rotors, the inner halves of the front parts of the blow bar between the discs are also exposed to wear, so that these surfaces can not be used as supporting surfaces in the rear part.

On the contrary, that is to say, when rotating around a central transverse axis, the rear part remains in the rear part and the front part remains in the front part, only the inner half after is the outside, and vice versa. In the vicinity of the disc width, the front support surfaces of the blow bars are adequately protected against wear by the retaining parts that hold them in position or by rotor disc sections located further outwards, front, which they form the support of the blow bar. Such a blow bar is known, for example, from DE 26 06 000 Al. Like many other known blow bars, it has a longitudinal cross section of uniform width; in contrast to other blow bars, however, its cross section has a backward inclined shape, whereby it is supported obliquely from the inside with the rear surfaces near the symmetrical axis in contact with the appropriately designed rotor disc sections. The blow bar is maintained in engagement with these parts in the front by wedges which act on the contact surfaces of the blow bar provided centrally in the front vertical and with respect to the symmetrical axis. The contact surfaces for the wedges in the rotor discs at the front are aligned essentially radially.

The cross section of the known blow bar has a uniform width and therefore contingent thereon a wide outer surface area which is essentially exposed to frictional wear. A decisive factor for a good attenuation is that the leading edge of the blow bar, which may be slightly, tilted forward for an improved effect. However, through such an inclination, the outer surface area is further increased, which means even more frictional wear. The ideal blow bar should be as close as possible to what is known from DE 28 11 376 A1. The blow bar described herein has a maximum thickness of 40 mm over considerable portions of the bar. its height and therefore only suitable for sand impactors where the size of the feeding material is relatively small. In addition, blow bars designed for reversible operation are known, which means that the impact edge is self-soiling due to wear. Such a blow bar is not suitable for large impactors, and would fracture under the load of the corresponding larger feed material. The object of the invention is to create a blow bar with the simplest cross sections which, however, is relatively thin in the vicinity of the impact edges, but which, however, can withstand the powerful forces generated by the effects of the impact, characteristics which favor wear curves and therefore lead to operational savings in terms of costs. An additional objective is to design the blow bar and the rotor to house them in such a way that, despite a simple cross-section design of the blow bar and simple rotor design, a safety system is carried out with a favorable and safe price for the required number of blow bars in the rotor. This problem is solved as follows: the cross section of the blow bar has essentially the shape of a double trapezoid with the long bases as symmetrical axes, so that the back of the blow bar corresponds to the height of each trapeze it is designed at right angles to the symmetrical axes to form a uniform surface above the height of the blow bar, and the contact surfaces on the back of the blow bar are designed with slot-type recesses that run in the longitudinal direction of the blow bar at a level with the symmetrical axis. The blow bar according to the invention is relatively more slender and therefore has a correspondingly small volume, and is therefore relatively inexpensive to manufacture with respect to the requirement of molten material.

In a further embodiment of the invention, the larger bases of the trapezoid corresponding to the symmetrical axis are approximately twice as large as the short bases corresponding to the width of the outer surfaces. In this case, the trapezoid or double trapezoid refers to the basic shape of the cross section, ignoring the groove type recesses. The latter is also designed as a trapeze (obelisk) and has level contact surfaces by means of which the blow bar is supported against the retention pieces 10 provided securely on the rotor. For securing the blow bar in the axial direction, a further embodiment of the invention proposes that on the front faces and starting from the rear of the blow bar, the groove-type recesses 15 are extended by providing a recess to accommodate axially effective interfitting elements. It is advantageous if the contact surfaces for the movable retaining parts in the front part of the blow bar are formed by current oblique sides of the double trapezoidal body such as an obelisk. Doing this without lifting or folding apart surfaces results in cost savings, so that the machining of the contact surfaces can be eliminated, since the blow bar supplied in the rotor is held by the retaining parts movable against the parts of retention provided securely in the rotor, preferably without tightly holding the blow bar. A further embodiment of the invention provides for the use of the blow bar according to the invention, wherein each blow bar is positioned inclined about its longitudinal axis in the direction of rotation of the rotor such that the oblique side directed outward from the corresponding trapezoid as an obelisk forms an impact surface which is inclined forward with respect to a section plane passing through the rotor shaft on the outermost edge of the blow bar forming the impact circle when the rotor is rotated, so that this outermost edge is brought forward visually with the other parts of the blow bar. It is particularly advantageous that the rotor comprises a plurality of rotor discs which are interrupted by peripheral recesses in all the rotor discs placed in alignment with each other, with blow bars according to the invention, whereby the peripheral recesses as shown in FIG. show from EP-0 666 111 Al and starting from the outer circumference of the rotor in opposition to the direction of rotation of the rotor which are inclined inwards and therefore the peripheral recesses are superimposed by retaining parts proportioned in a manner secure on the rotor to form a support for the blow bars, so that each blow bar is positioned inclined about its longitudinal axis in the direction of rotation of the rotor such that the front part of the oblique side directed outwardly from the Corresponding trapezium body as obelisk forms an impact surface which is inclined towards to forward with respect to a sectional plane passing through the axis of the rotor on the outermost edge of the blow bar forming the impact circle when the rotor is rotated, so that its outermost edge is brought forward in view of the other parts of the blow bar, whereby the movable retaining pieces provided between the front of the blow bars and the rotor supporting surfaces hold the support bars in an inclined manner in a supported manner from the front and from the inside in engagement with the prism-shaped retaining pieces provided securely on the rotor. A disadvantage of a rotor according to the document EP-0 666 111 A1 is that the back support which is superimposed on each peripheral recess is generated by loose retaining parts the small contact surfaces, so that positive retention is not guaranteed. In the drawing, the invention is illustrated as follows: Figure 1 is a front view of the blow bar according to the invention Figure 2 shows a section of the rotor with a blow bar, according to the invention, placed in the rotor, figure 3 is a front view of a rotor with the blow bar placed, according to the invention. As illustrated in Figure 1, the blow bar 1 has a longitudinal cross section, mirror-symmetric, in the form of a basic double trapezoid corresponding to the lines with added dashes and dashes. The large bases of each trapezium body correspond to a symmetrical axis 2, the short bases correspond to the width of the outer surfaces 3. The impact edges 4 are slightly rounded and lean toward the rear. The height h of each trapezoid corresponds to the rear part 5 of the blow bar 1 and is aligned at right angles to the symmetrical axis and thus forms a level surface 6 on the height 7 of the blow bar. On the rear part 5 at the level of the symmetrical axis is a recess 8, in trapezoidal shape, the sides of which are formed by the flat support surfaces 9, by means of which the blow bar is held against the parts 10 of retention provided securely on the rotor (figure 2). According to FIG. 1, the front part 11 of the blow bar has two impact surfaces 12, which "are formed by the inclined sides directed outwardly of the trapezoid as an obelisk." Slit-like recesses 8 present on both sides 13 recesses 14 which expand the groove in which, as shown in Figure 2, intercoupling elements 15 are axially effectively coupled, which are displaceably contained in cavities of the fixed retention parts 10. As shown in FIG. Figure 2, the blow bar is placed with its longitudinal cross section inclined forward in the rotor, which comprises a plurality of rotor discs The discs have a plurality of peripheral recesses 17 for accommodating a blow bar. peripherals are provided at the front of the blow bar in the direction of rotation of the rotor with an additional recess 18 approximately in straight angles with the purpose of accommodating a retaining member 19 movable, which keeps the rod in engagement with blowing part 10 provided retaining securely on the rotor. In figure 3 is the front view of a rotor, which, for reasons of simplification, is shown only with a blow bar 1. The rotor shaft around the rotor rotates according to arrow 20 and is marked with an x. The blow bar shown positioned at the top of the figure describes an impact circle 21 with its outer edge 4. Advancing from this edge towards the rotor axis x is a plane 22 in section. As clearly shown, the blow bar is positioned at an inclination with respect to the plane 22 in section such that the impact edge 4 is advanced with respect to the impact surface 12. The rotor comprises a plurality of discs 16 rotors welded together in their hubs 23. The blow bar according to the invention is of uncomplicated design and, due to its more slender shape, only a relatively small amount of wear material is needed. very expensive. The placement and removal of it is also without complications, which contributes to a reduction in maintenance costs.

Claims (8)

1. A blow bar for impeller rotors with a longitudinal cross-section mirror-symmetrical to the mirror for the purpose of reversibility, having surfaces at the rear in the direction of rotation of the rotor by means of which it is supported backward and radially from the inside against the retaining parts provided securely in the rotor, and having at the front contact surfaces for movably retaining parts which retain the blow bar in engagement with the retaining parts provided securely on the rotor , the blow bar is characterized in that the cross section of the blow bar is essentially in the form of a basic double trapezium with a larger base as a symmetrical axis, so that the back of the blow bar corresponds to the height of the each trapezoid is aligned at right angles to the symmetrical axis that forms a uniform surface or level on the height of the blow bar, and the contact surfaces are provided on the back of the blow bar and are formed by a groove-like recess that runs longitudinally on the blow bar and which is located at symmetric axis level.

2. The blow bar according to claim 1, characterized in that the larger bases of the trapezoid corresponding to the symmetrical axis are approximately twice as large as the smaller bases corresponding to the width of the outer surfaces.

3. The blow bar according to claim 1, characterized in that the groove-like recesses describe a trapezium-shaped cross section and constant level surfaces for the retaining parts provided securely in the rotor.

. The blow bar according to claim 1, characterized in that recesses extending to the groove-like recess are provided on the faces, and that they start from the rear of the blow bar to axially accommodate interference elements.

5. The blow bar according to claim 1, characterized in that the contact surfaces for the movable retaining parts in the front part of the blow bar are formed by current inclined surfaces of the double trapezium body as an obelisk.

6. The use of a blow bar according to claim 1, characterized in that each blow bar is positioned inclined about its longitudinal axis in i 'a direction of rotation of the rotor such that the side 5 oblique directed outward from the corresponding trapezoid as obelisk forms an impact surface is inclined forward with respect to a section plane passing through the rotor shaft on the outermost edge of the blow bar forming an impact circle when the rotor is rotated, so that its outermost edge is forward with respect to the other parts of the blower bar.

7. A rotor for impactors, comprising a plurality of rotor discs which are interrupted by 15 peripheral recesses placed in alignment with each other on all rotor discs, so that the peripheral recesses are inclined inward, starting from the outer circumference of the rotor opposite the direction of rotation of the rotor, with blow bars in compliance with claim 1, the The rotor is characterized in that the peripheral recesses are superimposed by the retaining pieces provided securely on the rotor to form a support for the blower bars, so that each blower bar is positioned inclined about its longitudinal axis in the direction of rotation. Rotation rotation 25 rotor so that the front part of the oblique surface facing outwardly of the corresponding trapezoid is an obelisk which forms an impact surface and which is inclined forward with respect to a section plane passing through the rotor shaft on the outermost edge of the blow bar forming the impact circle when the rotor is rotated, so that this outermost edge is forward with respect to the other parts of the blow bar.

8. The rotor according to claim 7, characterized in that the prism-like retaining pieces are provided securely on the rotor having level surfaces as complementary elements to the groove-like recesses in the blow bars.