CZ20021541A3 - Mill for grinding granular materials - Google Patents

Abstract

Mill for milling of granular materials, composed from milling cylinder (2) and from at least two - in relation to the milling cylinder counter-rotating milling runners (51, 52, 53), the axles of which (511, 521, 531) are parallel to the axle (20) of milling cylinder (2) and where the runners are both provided with means for ensuring the pressure to the milling cylinder (2) and they are located sliding in relation to the milling cylinder (2) such a way, that between their surface and between the near surface of milling cylinder (2) slots (6) are created, the size of which is adjustable in radial direction. Significant is that at least first from the milling runners (51, 52, 53) have the same or mutually different diameters (d), the size of which is up to 3/4<th> of milling cylinder size (D) as maximum.

Description

Mill for grinding granular materials

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 grindability and different grain sizes.

BACKGROUND OF THE INVENTION

Tubular - ball mills or vertical disc mills are currently used for grinding 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 asymmetrical grinding process caused by the indefinable contact of the grinding cartridge with the armor of the mill, which results in low energy efficiency of the grinding. Existing vertical disc mills are also characterized by low grinding efficiency, which can only be increased by repeatedly feeding the grinding material under the grinding discs. Another 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 equipment more energy-intensive.

A solution according to CZ PV 1999-999 of a medium-pressure multi-roll mill is also known, which consists of a driven roller and at least two grinding rollers whose axes are parallel to the axis of the driven roller and which are not self-propelled. The diameter of the grinding rollers is equal to at most 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 is in the direction of

• to • · ····

rotation of the driven roller decreases. The longitudinal axes of the grinding rollers then lie in the planes passing through the axis of the driven roller and are offset from the vertical plane interspersed by the axis of the driven roller by a gradually increasing angle α, β, γ. The disadvantage of this design without the grinding roll drive is that when changing the grinding parameters, the first grinding roll becomes stuck, slippage or even stopped, which reduces the efficiency and quality parameters of the grinding process and in some cases causes disturbances in press operation that require operator intervention.

SUMMARY OF THE INVENTION

These drawbacks are largely overcome by a mill for grinding granular materials consisting of a grinding roller and at least two grinding drums rotating in parallel with respect to the grinding roller, the axes of which are parallel to the grinding roller axis and which are provided with a means for securing the grinding roller. with respect to the grinding roller, they are displaceably mounted 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.

It is a further object of the invention that the planes passing through the longitudinal axes of the grinding drums are offset from the vertical plane passing through the longitudinal axis of the grinding roller by the angles α, β, γ of α = 0 in the case of three-drum equipment. ° to 30 °, β = 20 ° to 65 °, γ = 55 ° to 110 ° and, in the case of two-drum equipment, between α = 0 ° to 75 ° and β = 25 ° to 110 °.

-3 * ·· · <• · · · · ·

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

Finally, it is an object of the invention that the auxiliary power unit or the main power unit is provided with means for enabling the speed control of the grinding roller and / or the grinding treads and that the slits are adjusted in the same direction in all grinding treads. of 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 material to be ground between the grinding roller and the first grinding tread, as well as reducing wear on the surface of the grinding roller and the grinding treads. By the described modifications it is possible to grind material with humidity up to 15%.

Description of the figures in the attached drawings

Specific examples of construction according to the invention are schematically shown in the accompanying drawings, wherein Fig. 1 is a vertical section through a mill equipped with three milling drums; and Fig. 2 is a vertical section through an alternative embodiment of a mill equipped with two milling drums. Fig. 3 then shows a basic diagram of a mill drive with a common drive assembly; and Fig. 4 an alternative diagram of a mill drive with independent drive assemblies for driving a grinding roller and milling treads.

• ·

EXAMPLES OF THE INVENTION

The basic construction of the mill according to FIG. 1 consists of a funnel hopper 1, under which a grinding roller 2 with a diameter D, whose longitudinal axis of rotation 20 running in the direction of arrow R lies in a horizontal plane, is supported. The grinding roller 2 is mounted on a shaft 21 shown in FIGS. 3 and 4, which is coupled via a gearbox 3 to a main drive unit 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 drums 51, 52, 53 are co-rotationally aligned with this longitudinal axis 20 whose diameter d is at most 3/4 of the diameter D of the grinding roller 2. preferably, it is selected in 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 direction of rotation R of the grinding roller 2 by angles α, fi, 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 then provided with its own drive with adjustable peripheral speed, which is connected according to FIG. 3 either via a chain transmission 31 and a gearbox 3 to a common main drive unit 4 or 4 as shown in FIG. The grinding drums 51, 52, 53 are displaceably mounted 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 angular position of the grinding drums 51, 52, 53 can be adjustable relative to one another or different in diameter d. Finally, the grinding drums 51, 52, 53 are provided with means (not shown) for adjusting and controlling the radial thrust forces P acting towards grinding cylinder 2 and induced, for example, by the pressure of the pistons of hydraulic cylinders (not shown).

• · · · ·

During grinding, the crushed material is drawn into the slot 6 of the set width by counter rotating the grinding roller 2 and the first grinding tread 51, thereby crushing it. Gradual passage of the grist through further slots 6, with the width given by the setting of the other grinding treads 52, 53, further comminutes 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 more than three grinding treads 51, 52, 53, as shown in Fig. 2, which can be interchangeable. In the case of the two-drum version, the angles α, β of the angles of the planes 5111, 5211 of the longitudinal axes 511, 512 of the grinding treads 51, 52 are given by the relations α = 0 ° to 75 ° and β = 25 ° to 110 °. The grinding treads 51, 52, 53 may have the same diameter d and all may be provided with auxiliary drive units 4 ', depending on the type of grinder.

Industrial applicability

The mills according to the invention can advantageously be used as part of a process equipment for mass production of pulverulent materials, in particular for grinding materials with different grain size, large grindability and high moisture content such as cement, cement clinker, lime, limestone or ore.

PSP Engineering a.s ,.

Claims (8)

PATENT CLAIMS 1. A mill for grinding granular materials consisting of a grinding roller and at least two grinding treads rotating in parallel with respect to the grinding roller, the axes of which are parallel to the grinding roller axis and which are provided with means for securing pressure to the grinding roller and slidably mounted so that slits are formed between their surface and the facing surface of the grinding roller, 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 size of the grinding roller diameter (D). A mill for grinding granular materials according to claim 1, characterized in that the planes (5111, 5211, 5311) passing through the longitudinal axes (511, 521, 531) of the grinding treads (51, 52, 53) are from the vertical plane (200). passing through the longitudinal axis (20) of the grinding roller (2), inclined in the direction (R) of its rotation by angles (α), (β), (γ) · A mill for grinding granular materials according to claim 2, characterized in that the angle of camber (α), (β), (γ) is in the range of α = 0 ° to 30 °, β = 20 ° for three-drum equipment. to 65 °, γ = 55 ° to 110 °. A mill for grinding granular materials according to claim 2, characterized in that the angle of camber (α), (β) for two-drum equipment is between a = 0 ° to 75 ° and β = 25 ° to 110 °. 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 separate auxiliary drive unit (4 '). • • • -7 ·· ··· · A mill for grinding granular materials according to claims 1 to 4, characterized in that the drive of the one or more grinding drums is formed by a gear (31) coupled via a gearbox (3) to a main drive unit (4) of the grinding roller (2). A mill for grinding granular materials according to claim 5 or 6, characterized in that the auxiliary drive unit (4 ') or the main drive unit (4) is provided 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 set in the same direction in the direction of rotation (R) of the grinding roller (2) for all grinding treads (51, 52, 53). is set wider or narrower on at least one of the grinding treads (51,52, 53).