RU2288037C1 - Milling set for disk mill - Google Patents

Abstract

FIELD: milling equipment for disk mills.

SUBSTANCE: milling set for disk mill has two disks assembled from sections, namely stator disk with inlet opening and rotor disk. Working surface of said disks has peripheral annular zone with working knives and channels between knives and central annular zone with integral shortened and small-sized knives. Central annular zone is made conical, with generatrix of said zone being inclined at an angle of 8-13 deg to supporting surface of sections and is joined with inlet peripheral edge of peripheral annular zone. Integral knives of central annular zone are arranged in alternation with two small-sized knives, between which knives one shortened knife is positioned. End part of peripheral zone of sections is equipped with additional working knives located within channels between knives of main working knives. All the knives may be arranged tangentially to circle of inlet opening of stator disk. Non-operating bottom surface of central conical annular zone may be arranged at an angle of 8-13 deg to supporting surface of section.

EFFECT: intensified milling process and increased efficiency.

3 cl, 6 dwg

Description

The invention relates to grinding sets of disk mills and is intended for use in the pulp and paper industry, construction, chemical and other industries.

Known grinding headset of a disk mill, including rotor and stator disks, the working surface of which is divided into sectors with knives and through-knife grooves applied parallel to one of the radial edges of the sector / SU 878847, 11/07/1981 /.

A disadvantage of the known headset is that part of the suspension remains untreated, because due to turbulence and pressure drops, part of the suspension passes through the grooves, without falling into the grinding zone.

Closest to the technical nature of the invention is a grinding headset of a disk mill, which includes stator assemblies with an inlet and rotor disks assembled from sectors, the working surface of which has a peripheral annular zone with working knives and inter-knife grooves evenly located from the entrance to the outlet edges and a central annular zone with whole and small knives. (Equipment for pulp and paper production, vol. 1. M .: Forest industry, 1981, p. 177-179, fig. 4.11 (H). C.).

A disadvantage of the known headset is the low intensity of the mechanical and hydrodynamic effects on the fibrous semi-finished product, the ability to process only finely dispersed suspensions with a low concentration of the fibrous semi-finished product evenly distributed in them, and the impossibility of its preliminary processing.

The objective of the invention is the intensification of the grinding process, improve its quality, productivity and reduce energy consumption.

To solve this problem, in a grinding headset of a disk mill, including a stator with an inlet and rotor disks assembled from sectors, the working surface of which has a peripheral annular zone with working knives and interknife grooves evenly located from the inlet to the outlet edges of the sectors and a central annular zone with solid and small knives, according to the invention, the Central annular zone is made conical with a slope forming relative to the supporting surface of the sectors at an angle of 8-13 ° and wife inlet circumferential edge of the annular peripheral zone, wherein the solid central annular zone knives are alternated with two small blades, between which is mounted a shorter blade, and the end portion of the peripheral sectors of the zone is provided with additional working knives mounted in grooves mezhnozhevyh main working knives.

All knives of the grinding headset can be placed tangent to the circumference of the inlet of the stator disk.

The non-working bottom surface of the central conical annular zone of the relative supporting plane of the sector can be made at an angle of 8-13 °.

In figure 1. depicts a frontal view of the grinding headset disk mill assembly.

(The circle nearest to the center of the disks, shown by a thin line, is the edge of the stator disk inlet. The annular cavity located between the inlet circumferential edges of the stator disk and the sectors attached to it and the rotor disk is an acceleration zone. Tangent tangents to the inlet circumference are drawn in thin lines. stator disk on which all knives are placed.)

Figure 2 shows one of the sectors of the grinding headset disk mill.

(The arrows indicate the direction of movement of the fibrous semi-finished product. The working surfaces of the knives of the conical annular zone are shaded. The working surfaces of the knives of the annular zone are blackened. The working surfaces of the knives of the conical annular zone are shaded.)

Figure 3 is a section aa in figure 2.

Figure 4 is a section along BB in figure 2.

Figure 5 is a section along bb in figure 2.

Figure 6 shows a cross section of the stator and rotor disks in the working, mated position.

The grinding headset of the disk mill includes rotor and stator disks (Fig. 1), divided into sectors (Fig. 2), the working surface of which has a peripheral working (frontal) annular zone G and working knives evenly distributed from the input 1 to the output 2 circumferential edges of the sectors 3. The end part of the peripheral zone of the sectors is equipped with additional working knives 4 installed in the inter-knife grooves 5 of the main working knives 3.

и сопряжена с входной окружной кромкой периферийной кольцевой зоны и имеет цельные 7, укороченные 8 и малые 9 ножи. Цельные ножи 7 центральной кольцевой зоны чередуются с двумя малыми ножами 9, между которыми размещен один укороченный нож 8.The working surface of the sectors has a central annular zone D, which is made conical with a slope forming relative to the supporting surface of 10 sectors at an angle

and is coupled to the inlet circumferential edge of the peripheral annular zone and has solid 7, shortened 8 and small 9 knives. Solid knives 7 of the central annular zone alternate with two small knives 9, between which one shortened knife 8 is placed.

The given interval of angles is optimal, since an increase in the angle leads to clogging of the inter-knife space, which degrades the quality and increases energy consumption, and a decrease in the angle negatively affects the intensification of the grinding process.

For uniform distribution of material (semi-finished product) across sectors of the disks, all knives are placed tangent to the circumference of the inlet of the stator disk from the center O 'with an eccentricity "e" (Fig.2) relative to the center O of the rotor and stator disks, and the idle bottom surface of the central conical annular zone relative to the reference plane of the sector is made at an angle of 8-13 °.

All sectors of the grinding headset of a disk mill are mounted on bearing disks (not shown conditionally).

In the working position, the mating knives 3, 4, 7, 8 and 9 of the rotor and stator disks, as well as the inter-knife grooves 5, intersect at an arbitrary angle, therefore, the inter-knife grooves of the rotor and stator disks open from the inter-knife gap are interconnected.

The pairing of the Central annular conical zone D with the inlet circumferential edge 1 of the peripheral annular zone G is made with a difference in height at the place of their conjugation (Figs. 3, 4, 5 and 6).

The working surface of the headset, covering the central conical annular zone D, consists of three annular sections having the following characteristic features (figure 2):

- section I is a non-working bottom surface of the disks and grooves 5, starting from the input circumferential edge of 6 sectors with protruding edges of solid knives 7 to the circumferential line of edges not reaching shortened knives 8;

- section II - inoperative bottom surface of the grooves 5 with the protruding parts of the knives 7 and 8, limited by the boundary circumferential lines of this section;

- section III - non-working bottom surface of the inter-knife grooves 5 with the protruding parts of the knives 7, 8 and 9, limited by the peripheral circumferential lines of this section.

The working surface of the headset, covering the peripheral annular working area G, consists of two annular sections having the following characteristic features:

- section IV with a length from the input circumferential edge 1 to the radius R5;

- section V with a length from radius R5 to radius R6.

Grinding headset disk mill works as follows.

Torque from the drive is transmitted to the shaft mounted on its leading end, a movable carrier disk (conventionally not shown) and a rotor disk mounted on it.

Pre-treatment of the semi-finished product is carried out in zone D (figures 1, 2 and 6) in the following order.

The fibrous coarse suspension under pressure enters the acceleration zone through the inlet of the stator bearing disk, where, due to friction forces with the fixed wall of the stator and the moving wall of the rotating rotor disks forming the accelerating cavity, it is twisted, rushing under the action of centrifugal and tangential forces towards the circumferential edge 6 sectors (shown in arrows 1 and 2) tangentially to the circumference of the inlet of the carrier disk.

After crossing the input edge of the 6 sectors, the suspension passes into the maximum open section 1 of the central annular conical zone D of the pre-treatment, where it is impacted by the protruding ends of the solid knives 7 in the form of initial processing (Figs. 1, 2 and 6), which ensures the destruction of the most coarse fractions of the suspension.

The semi-finished product that has passed the first stage of processing, under the action of a growing centrifugal force, enters the tapering section P of the pre-treatment zone D, where it undergoes the second stage of processing, which consists in a more intensive action from the side of the solid knives 7 and the protruding ends of the shortened knives 8 crossing this section, with the simultaneous alternation, due to this, of the pressure drops, accompanied by hydrodynamic effects, as well as the action of shear forces that occur during the transition of the processed half the briquette through the working surfaces of the knives 7 and 8 into the inter-knife grooves 5, which ensures further destruction of the largest fraction formed after the semi-finished product passes through section 1.

The semifinished product, which has passed the second stage of processing, under the action of a continuing centrifugal force, enters the annular cavity of the section Ш of zone D, tapering to a minimum in height, where it undergoes the third stage of processing, which consists in the most intensive action from the normal, tangential and hydrodynamic forces increasing to the maximum , noted at the previous stages of its processing, which allows for the most in-depth preliminary development of the semi-finished product (Figs. 1, 2 and 6).

The semifinished product, which has passed the third pretreatment stage, under the action of a centrifugal force increasing to a maximum, moves to the annular working (frontal) cavity of the section IV zone D of the final processing, where it is distributed along the inter-knife grooves 5, and the fibrous semifinished product is distributed to the backwater from the knives 4 and then moves to the inter-knife grooves 5 of the paired headset open from the side of the inter-knife gap, passing through the working edges of the knives 3, undergoing at the same time increasing th and hydrodynamic effects, providing separation in a more subtle level of fibers (1, 2 and 6).

The semifinished product, which has passed the first stage of final processing, moves to the annular frontal cavity of section V of the final processing zone G, where it is distributed along the inter-knife grooves 5 of the rotor and stator disks and passes into the grooves 5 of the associated headset open from the side of the inter-knife gap, undergoing mechanical and hydrodynamic effects providing even finer fiber separation. Semi-finished product, caught in the inter-knife groove 5 near the circumferential edge 2, is ejected into the receiving cavity of the output collector, and through it is fed to the collection of the processed semi-finished product (Figs. 1, 2 and 6).

Using the proposed grinding headset disc mill in comparison with well-known headsets will allow:

- increase productivity by reducing the number of cycles of passage of the fibrous semi-finished product through the grinding zone;

- to improve the processing quality of the fibrous semi-finished product by increasing the frequency and magnitude of the pressure drops, which leads to the emergence of a cavitation effect;

- to intensify the processing of the semi-finished product by increasing the total value of the impact of high-frequency loading cycles on the fibrous semi-finished product;

- provide for the forced transportation of the processed semi-finished product into the receiving cavity of the output collector;

- reduce energy consumption by increasing the time of one pass of the processed semi-finished product through the cavity of the working areas while enhancing the mechanical and hydrodynamic effects.

The technical result consists in increasing the intensification of the grinding process by increasing the number of mechanical and hydrodynamic effects on the fibrous semi-finished product in one pass through the headroom of the headset and in improving its quality by providing pre-processing before it enters the peripheral annular zone of the final grinding.

Claims (3)

1. Grinding headset of a disk mill, including a stator with an inlet and rotor disks assembled from sectors, the working surface of which has a peripheral annular zone with working knives and inter-knife grooves evenly spaced from the input to the outlet edges of the sectors, and a central annular zone with integral and small knives, characterized in that the central annular zone is made conical with an inclined generatrix relative to the supporting surface of the sectors at an angle of 8-13 ° and is conjugated with the input circumferential second annular peripheral zone, wherein the solid central annular zone knives are alternated with two small blades, between which is mounted a shorter blade, and the end portion of the peripheral sectors of the zone is provided with additional working knives mounted in grooves mezhnozhevyh main working knives. 2. Grinding headset according to claim 1, characterized in that all the knives are placed tangent to the circumference of the inlet of the stator disk. 3. The grinding set according to claim 1, characterized in that the non-working bottom surface of the central conical annular zone relative to the supporting plane of the sectors is made at an angle of 8-13 °.

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