RU2085287C1 - Pressure roll grinder - Google Patents

Abstract

FIELD: mining, coal, chemical and building materials industries; grinding carbonate and alumosilicate ores, clinker and technogeneous materials. SUBSTANCE: pressure roll grinder has shell 1 accommodating rolls 2 and 3 placed in a spaced relation to each other and made in the form of drums 4 and 5. Mounted on the drums are segments of bow-shaped profile along the axes of the rolls. One of the drums carries convex segments 11 and the other one has concave segments 10. The segments are prestressed with the aid of wedges 7,8. The segments are secured by means of dolts 6 in the central portion of the drum surfaces and are arranged so that sunk segments 11, 12 are disposed between projecting segments 9, 10. All the segments are provided with end and central bosses having inclined grooves resting on wedges installed in longitudinal grooves of mounting drums and made in the form of a taper key with inclined end face surfaces. The wedge angles are equal to α = 30 to 50 deg in the central part of the segment and b = 50 to 75 deg at the sides. EFFECT: improved quality of grained product. 6 dwg

Description

 The invention relates to equipment for grinding small-sized materials, namely, to the design of press-roll grinders used in the building materials industry for grinding carbonate and aluminosilicate rocks, clinker, industrial materials, as well as in mining, coal, chemical and other industries.

Known press roll shredders, including a pair of rolls mounted in bearings and rotating towards each other [1,2]
However, these shredders are characterized by increased energy consumption due to the significant grinding efforts. For example, when grinding cement clinker for its effective destruction, it is necessary to ensure grinding forces equal to 1.5 2 t / cm roll width or more.

 The closest technical solution to the claimed is a roll crusher [3] containing grinding segments mounted on a skeleton in the form of a drum using longitudinal fasteners located with a gap in the grooves of the skeleton. The cross-sectional shape of the grooves and fasteners correspond to each other. Moreover, the latter are mounted in the gaps using wedges. Segment mount options may vary.

However, this design has a number of significant drawbacks:
the use of a technical solution does not provide increased wear resistance of the working surface of the removable segments;
the smooth surface of the rolls does not provide a reliable grip of the crushed mixture and lump materials for delivery to the maximum pressure zone, especially at an increased peripheral speed of the rolls;
a shredder with rolls of known design has increased maintainability in view of the complexity of the attachment points of the segments;
the impossibility of restoring the geometric profile of segments in the process of their natural wear;
the inability to quickly replace one or more segments if they break during the operation of the grinder.

 The aim of the invention is the intensification of the grinding process, increasing the operational reliability and the overhaul period of the mill rolls.

 This goal is achieved by the fact that in the press-roll grinder containing the housing, rolls installed therein with a clearance, made in the form of a drum, on which segments are mounted. According to the decision, the segments are rigidly mounted on the drums in their central part and pre-tensioned with wedges installed in the longitudinal grooves of the landing drums, have an arched profile and are convex on one and concave on the other drum. Moreover, all segments alternate as protruding and recessed and have end and central tides, and the wedges are made in the form of a wedge dowel with inclined end surfaces and are supported on the end and center tides of the segments in their inclined grooves.

The value of the angles of the wedges in the central part of the segments is α 30 50 ^o , and along the edges b 50 75 ^o .

Compared analysis with the prototype shows that the claimed technical solution differs by installing on the surface of the landing drums of the rolls prestressed concave and convex segments having an arcuate geometric profile along the axis of the rolls, instead of their straight profile, creating large radial loads. Pre-stress is achieved using wedges installed in the longitudinal grooves of the landing drums. Using a more reliable and simple method of fastening segments only in their central part instead of the more complex one. All segments alternate with each other as protruding and recessed, and are made with end and central tides, resting on their wedges in their inclined grooves. The value of the angles of the wedges in the central part of the segment corresponds to a 30 50 ^o , and along the edges b 50 75 ^o .

 Thus, the claimed technical solution meets the criterion of "novelty."

Comparison of the claimed technical solution with other known solutions shows that the chopper containing the housing with rolls installed in it with a gap made in the form of a drum, on which removable segments are mounted using wedges are known [3] However, the use of the proposed technical solution with the above features provides achievement of new properties, consisting of:
in reducing wear of the working surfaces of the removable segments due to their prestress (compression of the surface layer of the segments in contact with the crushed material);
in providing a more developed working surface of the rolls, which has a reliable grip of the charge and allows grinding material of a wider fractional composition;
in reducing the repairability of the grinder due to the simplification of its design;
in increasing the overhaul period of the grinder rolls by maintaining a given geometric profile during their operation;
the ability to quickly replace one or more segments that have defects (cracks, sinks, chips, etc.) during the operation of the grinder.

 All this allows us to conclude that the technical solution meets the criterion of "inventive step".

In FIG. 1 shows the chopper rolls, a cross section; in FIG. 2
chopper rolls assembly, longitudinal section; in FIG. 3 segment convex; in FIG. 4 segment concave; in FIG. 5 fastening of convex segments on the grinder drum; in FIG. 6 fastening of concave segments to the chopper drum.

 The press roll mill contains mounted in the housing 1, rolls 2,3, composed of mounted on drums 4,5 using, for example, bolted joints 6 (Fig. 1) and wedges 7,8 (Fig. 2), convex 9 ( Fig. 3) and concave 10 (Fig. 4), arcuate segments. At the same time, each of the convex and concave segments is in contact along the lateral faces with recessed segments 11, 12, thus forming a relief profile of the chopper rolls. The drums are rigidly fixed on their sides on the hubs 13.14 (Fig. 2), planted on the rollers 15.16 and interconnected by ties 17. Between the seating surfaces of the drums and wedges fixed in their grooves 18, the adjustment plates 19 are installed (Fig. . 5). All segments are in contact with the wedges through the inclined surfaces of the grooves 20 made in the central 21 and end 22 tides (Fig. 6).

 Press roller grinder operates as follows. The crushed material enters through the feed hole into the inter-roll space of the rolls 2,3 of the grinder (Fig. 1). The embossed surface of the rolls, formed by protruding 9.10 and recessed 11.12 segments, provides reliable grip of the charge. To increase the operational life of the rolls, pre-stresses are applied using wedges 7.8, both protruding 9.10 and recessed 11.12 segments (Fig. 2). Wedges 7.8 are installed with their base in the longitudinal grooves of 18 reels 4.5, and the upper part in the inclined surfaces of the grooves 10 of the central 21 and end 22 tidal segments (Fig. 3.4), which ensures their strict fixation on the surface of the drum. With the application of forces F (when tightening the bolts in the central part of the segments), the segment (for example, convex 10) by the inclined surfaces of the grooves 20 of the tides 21 act on the wedges recessed in the grooves 18, moving them apart from the center (Fig. 5,6). The wedges, moving apart along the longitudinal grooves (guides) 18 of the landing drum, act on the inclined surfaces of the grooves 20 of the end tides of the segments along their edges 22, providing their prestress (compression of the surface layer in contact with the crushed material and stretching of the surface layer facing the drum surface )

The uniform tension of the segments increases the wear resistance of their working surfaces. The bending moment, providing stress segments, arises from the force Q _y on the length of the shoulder l. To reduce the friction force on the basis of the wedges, there are samples. To ensure the effective transmission of the initial force F to the lateral parts of the segments, it is necessary that the value of the angles of the wedges is: in the central part of the segments a 30 50 ^o , and along the edges b 50 70 ^o . If these conditions are violated (a <30 ^o , b> 75 ^o and a> 50 ^o , b <50 ^o ), the effect of wedge transmission of forces is not implemented effectively.

 Under the influence of the forces of grinding materials in the process, an additional compression of the surface of the segments occurs due to their deflection, therefore, the segments are mounted on roll drums with an annular gap d the value of which does not exceed the limit value of the deflection of the segments.

 To maintain the given geometric shapes and sizes of the chopper rolls (to maintain a constant gap between the rolls), a set of adjusting plates 19 is installed between the bases of the wedges 7.8 and the drums 4.5 of the rolls.

 Using the design of prestressed removable segments ensures uniform stress distribution and reduced wear on the working surface of the segments, has a reliable grip of the crushed material, reduces the grinder's repair life, increases the overhaul period of the grinder rolls, and makes it possible to quickly replace one or more segments that have defects.

 References.

 1. The patent of Germany N 328630, cl. B 02 C 4/92, 1984 analogue.

 2. Autosvid.SSSR N 655422, cl. B 02 C 4/04, B.I. N 13, 1979 analogue.

 3. Autosvid.SSSR N 1426633, cl. B 02 C 4/30, 1988 prototype.

Claims (2)

 1. Press roller grinder, comprising a housing mounted on it with a roll gap, made in the form of having longitudinal grooves of drums with segments pre-stressed with wedges installed with longitudinal grooves of drums, characterized in that the segments have an arched profile, made convex on one and concave on the other drum, equipped with end and central tides with inclined grooves and rigidly fixed in their central part on the drums, with some segments made protruding and others recessed with their alternation, while the wedges are made in the form of wedge dowels with inclined end surfaces and are supported on the end and central tides of the segments in their inclined grooves. 2. The chopper according to claim 1, characterized in that the value of the angles of the wedges in the Central part of the segments is 30 50 ^o , and at the edges 50 75 ^o .

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