SK287905B6 - Mill for milling of granular materials - Google Patents

Abstract

Mill for grinding granular materials consisting of a grinding roller (2) and at least two in view of the grinding roller (2) in opposite rotating grinding treads (51, 52, 53) whose axis (511, 521, 531) are parallel to the axis (20) grinding roller (2), which are both equipped with means to ensure the down force on the grinding roller (2) and both are given the grinding roller (2) slid ably stored so that between the surface and the apparent surface of the grinding roller (2) are formed slots (6) the size of which is radially adjustable. According to the invention is at least the first of the grinding treads (51, 52, 53) equipped with a self-propelled, with the grinding treads (51, 52, 53) are mutually identical or different diameters (d), whose maximum size is 3/4 size diameter (D ) grinding roller(2).

Description

Technical field

The invention relates to the construction of a mill for grinding granular materials, in particular a medium-pressure horizontal roller mill for grinding materials with different grinding ability and different grain sizes.

BACKGROUND OF THE INVENTION

Tube mills or vertical disc mills are currently used to grind materials of different hardness and granularity, such as cement raw materials, cement clinker, lime, limestone, ores and pigments. The disadvantage of tubular - ball mills is in particular the unsymmetrical grinding process caused by the indefinable contact of the grinding cartridge with the armor of the mill, resulting in low energy efficiency of the grinding. Current vertical disc mills are characterized by an equally low grinding efficiency, which can only be increased by repeatedly feeding the milled material under the grinding wheels. A further disadvantage of these mills is their considerable size and weight, which at the present long grinding time makes the energy-intensive operation of the grinding device of this type more efficient.

A solution according to CZ PV 1999-999 of a medium-pressure multi-roll mill is also known, which consists of a drive roller and at least two grinding rolls whose axes are parallel to the axis of the driven roller and which are not equipped with their own drive. The diameter of the grinding rollers is at most equal to half the diameter of the driven roller and the grinding rollers are arranged such that rest slots are formed between the surface of each of them and the driven roller, the width of which decreases in the direction of rotation of the driven roller. The longitudinal axes of the grinding rollers then lie in the planes passing through the axis of the driven roller and are inclined from the vertical plane translated by the axis of the driven roller by a gradually increasing angle α, β, γ. The disadvantage of this design without the grinding roller drive is that changing the parameters of the material to be grinded leads to jamming, slipping and even stopping of the first grinding roller, which decreases the efficiency and quality parameters of the grinding process and in some cases causes disturbances of press operation. .

SUMMARY OF THE INVENTION

The aforementioned disadvantages are largely eliminated by the grinding mill of the granular materials consisting of a grinding roller and at least two grinding wheels rotating in parallel with the grinding wheels, the axes of which are parallel to the grinding roller axis and which are both provided with means for securing the pressure to the grinding roller. relative to the grinding roller, they are displaceably disposed such that slots are formed between their surface and the facing surface of the grinding roller, the size of which is radially adjustable. It is an object of the invention that at least the first of the grinding treads is self-propelled, wherein the grinding treads have an identical or mutually different diameter whose size is at most 3/4 of the size of the grinding roller diameter (D).

It is a further object of the invention that the planes passing through the longitudinal axes of the grinding tread are angled α, β, γ by angles α, β, γ in the range of a = 0 in the direction of rotation of the grinding roller. ° to 30 °, β = 20 ° to 65 °, γ = 55 ° to 110 °, and with two-drum equipment in the range of a = 0 ° to 75 ° and β = 25 ° to 110 °.

It is also essential that the drive of the one or more grinding treads consists of a separate auxiliary drive unit or a transmission coupled via a gearbox to the main drive unit of the grinding roller.

Finally, it is an object of the invention that the auxiliary drive unit or the main drive unit is provided with means for enabling the rotation control of the grinding roller and / or the grinding treads and that the slot size is set equal in all grinding treads or at least one of the grinding treads set wider or narrower.

The new design achieves a new and higher effect by ensuring regular operation of the mill, ensuring better grinding of the ground material between the grinding roller and the first grinding tread, as well as reducing wear on the grinding roller surface and the grinding tread. The described modifications allow grinding of material with a moisture content of up to 15%.

BRIEF DESCRIPTION OF THE DRAWINGS

Specific examples of mill construction according to the invention are schematically illustrated in the accompanying drawings, where:

Fig. 1 is a vertical section through a mill equipped with three grinding treads;

Fig. 2 is a vertical sectional view of an alternative embodiment of a mill equipped with two grinding treads;

Fig. 3 shows a basic diagram of a mill drive with a common power unit, and FIG. 4 illustrates an alternative mill drive scheme with independent drive units for grinding roller and grinding tread.

DETAILED DESCRIPTION OF THE INVENTION

The basic construction of the mill according to FIG. 1 is formed by a funnel-shaped hopper 1, beneath which a grinding roller 2 with a diameter D is laid, whose longitudinal axis of rotation 20 running in the direction of the arrow R lies in a horizontal plane. The grinding roller 2 is supported on the shaft 21 shown in FIG. 3 and 4, which is coupled via a gearbox 3 to a main drive assembly 4, for example an electric motor.

In the upper right quadrant of the outer surface of the grinding roller 2 given by the vertical plane 200 passing through the longitudinal axis 20, three grinding treads 51, 52, 53 are coaxially rotatably aligned with this longitudinal axis 20, whose diameter d is at most 3/4 of the diameter D of the grinding roller 2. it is preferably selected within the range of D: d = 1: (0.2-0.6). The planes 5111, 5211, 5311 passing through the longitudinal axes 511, 521, 531 of the grinding treads 51, 52, 53 are then deflected from the vertical plane 200 in the rotational direction R of the grinding roller 2 by angles α, β, γ of magnitude. a = 0 ° to 30 °, β = 20 ° to 65 °, γ = 55 ° to 110 °. At least the first of the grinding treads 51, 52, 53 is self-propelled with adjustable peripheral speed, and this is connected according to FIG. 3 either via a chain transmission 31 and a gearbox 3 to a common main drive unit 4 and / or is provided with its own auxiliary drive unit 4j, as shown in FIG. 4. The grinding treads 51, 52, 53 are displaceably disposed relative to the grinding roller 2 such that slots 6 are formed between their surface and the facing surface of the grinding roller 2 so that their size is either the same or decreases gradually in the direction of rotation R and is radially adjustable. Likewise, the relative angular position of the grinding treads 51, 52, 53 can be adjustable and can have the same or different diameter d. Finally, the grinding treads 51, 52, 53 are provided with means (not shown) for securing and adjusting the radial thrust forces P acting towards the grinding roller 2 and exerted, for example, by the piston pressure of the hydraulic cylinders (not shown).

In grinding, the crushed material is pulled into the slot 6 of a set width by counter-rotating the grinding roller 2 and the first grinding tread 51, thereby crushing it. The gradual passage of the milled material through further slots 6, with the width given by the adjustment of the other grinding treads 52, 53, further crushes to the desired grain size.

The described embodiment is not the only possible construction of the mill according to the invention, but the mill can be equipped with only two or even more than three grinding treads 51, 52, 53, as shown in FIG. 2, which may be interchangeable. In the case of the two-drum version, the angles of α, β of the inclination planes 5111, 5211 of the longitudinal axes 511. The 512 grinding treads 51, 52 are given by a = 0 ° to 75 ° and β = 25 ° to 110 °. The grinding treads 51, 52, 53 may have the same diameter d and all may be equipped with auxiliary drive units 4 'depending on the type of material to be ground.

Industrial usability

The mills according to the invention can advantageously be used as part of the process equipment for large-scale production of pulverulent materials, in particular for grinding materials with different grain sizes, large grinding capacity and high moisture content such as cement, cement clinker, lime, limestone or ores.

Claims (8)

PATENT CLAIMS 1. A mill for grinding granular materials consisting of a grinding roller and at least two grinding wheels rotating in parallel with respect to the grinding roller, the axes of which are parallel to the grinding roller axis and which are both equipped with a means for securing the gripper to the grinding roller and slidably disposed such that slits are formed between their surface and the grinding roller surface, the size of which is radially adjustable, characterized in that at least the first of the grinding treads (51, 52, 53) is self-propelled, the grinding treads (51 52, 53) have the same or different diameter (d), which is at most 3/4 of the diameter (D) of the grinding roller (2). The mill for grinding granular materials according to claim 1, characterized in that the planes (51 11, 5211, 5311) passing through the longitudinal axes (511, 521, 531) of the grinding tread (51, 52, 53) are from the verical plane (51). 200), which passes through the longitudinal axis (20) of the grinding roller (2), inclined in the direction (R) of its rotation by angles (α), (β), (y). The mill for grinding granular materials according to claim 2, characterized in that the angle of deflection (α), (β), (y) of the three-drum equipment is in the range of a = 0 ° to 30 °, β = Δ = 20 ° to 65 °, γ = 55 ° to 110 °. The mill for grinding granular materials according to claim 2, characterized in that the angles of camber (α), (β) for two-drum equipment are between α = 0 ° to 75 ° and β = 25 ° to 110 °. The mill for grinding granular materials according to claims 1 to 4, characterized in that the run of one or more grinding treads (51, 52, 53) is formed by a separate auxiliary drive unit (4 '). A mill for grinding granular materials according to claims 1 to 4, characterized in that the drive of the one or more grinding treads (51,52, 53) is formed by a transmission (31) coupled via a transmission (3) to the main drive assembly (4). grinding roller (2). 15 A mill for grinding granular materials according to claims 5 or 6, characterized in that the auxiliary drive unit (4 ') or the main drive unit (4) is equipped with means for enabling the speed control of the grinding roller (2) and / or the grinding treads (4). 51, 52,53). A mill for grinding granular materials according to claims 1 to 7, characterized in that the size of the slots (6) is in the direction of rotation (R) of the grinding roller (2) for all the grinding treads (51, 52, 53). 20 is set equal or at least one of the grinding treads (51, 52, 53) is wider or narrower.