High pressure roller press with vibrating side walls

Abstract

The invention relates to a high-pressure roller mill (100) for comminuting brittle roll stock (M), having at least two, side-by-side arranged, counter-rotating roller mills (110, 120), between which a roller gap (W) is configured, wherein the first roller mill (110) is a fixed roller and the second roller mill (120) is a floating roller, and the high-pressure roller mill has one side wall (150, 150') each on both ends of the roller gap (W). According to the invention, the one side wall (150, 150') each has a vibration device (160) which places the one side wall (150, 150') each in mechanical oscillation.

Description

Technical Field

[0001] The present invention relates to a high-pressure roller press for crushing brittle crushed materials, having at least two rollers arranged side by side and rotating in opposite directions, with a roller gap between the rollers, wherein the first roller is a fixed roller and the second roller is a floating roller, and the high-pressure roller press has a sidewall at each of the two ends of the roller gap. Background Technology

[0002] To crush or compact brittle and granular materials such as ores and rocks, high-pressure roller presses are typically used. These consist of two side-by-side, counter-rotating, rotatably supported pressure rollers of the same size, which rotate at the same circumferential speed and have a narrow gap between them. The material to be crushed or compacted is guided through this gap, where it is crushed or compacted under high pressure. The result of this process, i.e., the crushing or compaction, is largely related to the material properties of the material to be crushed. The non-shearing and non-impact crushing process described herein is first described by [the author / author]. It was described as high-pressure crushing in the German publication DE2708053A1, and it has since been considered a type of crushing other than grinding and crushing by shearing.

[0003] according to The high-pressure roller press for crushing granular materials is fundamentally different from other presses used for crushing other materials. In particular, the high-pressure roller press for crushing rocks differs from the roller press for crushing grains. Grain is ground in the grain roller. The maximum weight range of the grain roller is 100 kg. The entire structure of the grain roller assembly differs significantly from that of the high-pressure roller press. Furthermore, the grain roller operates in a shearing manner, while the high-pressure roller press does not. This means that the two rollers have precisely the same surface velocity in the gap between them and there is no slippage between them during operation.

[0004] High-pressure roll presses also differ significantly from strip rolls used for rolling steel. Strip rolls excel due to their application-specific, quiet, and stable operation. The steel between the rolls is either well-stretched due to heat deformation or capable of cold deformation. The quiet and stable operation of the strip rolls is particularly evident due to the nature of the rolling method. Therefore, it is possible to operate the strip rolls with two parallel, relatively vertically arranged rolls, where the roll gap pressure can be generated by the rolls' own weight or by hydraulic aids. Horizontally, perpendicular to the gravity that presses the upper roll onto the strip steel, the steel to be rolled passes through the roll gap. Depending on the steel being rolled, the roll gap speed can reach up to 200 km / h. Although the forces acting in strip rolls are many orders of magnitude larger, strip rolls can be compared to dough rolling rollers that roll and expand pizza dough. In contrast, high-pressure roller presses used for crushing ores and rocks typically have horizontally arranged rollers with vertical channels for crushing the material. Here, the roller gap speed in high-pressure roller presses for crushing ores and rocks can reach a low level in the double-digit km / h range.

[0005] Belt rollers used for steel operate at different limits than high-pressure roller presses. The belt rollers rotate rapidly and evenly, deforming the extensible steel beneath them. High-pressure roller presses operate slowly, and the material being rolled spontaneously and abruptly avoids the pressure in the gap due to its brittle nature. In high-pressure roller presses, the rollers are arranged horizontally side-by-side, creating the gap in which the material being rolled passes vertically. High-pressure roller presses have gap pressures of 50 MPa and above. Because of the horizontal arrangement of the rollers and the operation with brittle materials, the overall mechanical properties of high-pressure roller presses differ from those of vertically arranged belt rollers. Furthermore, the belt rollers exhibit a buffered, uniform operation due to the extensibility of the steel being rolled.

[0006] If the material being crushed in a high-pressure roller press is unevenly mixed with air, it may move into the air chamber as it passes through the roller gap, thus avoiding the high pressure in the gap and significantly reducing the crushing efficiency of the high-pressure roller press. Furthermore, this causes uneven operation of the high-pressure roller press, with each roller rotating and oscillating as the roller drive is repeatedly braked and then freed. This sudden load change continues throughout the high-pressure roller press and can be observed as vibration throughout the entire press. Under adverse conditions, this vibration can extend to the base and, in severe cases, even damage the base.

[0007] To achieve uniform, stable, and quiet operation of a high-pressure roller press, the crushed material is uniformly applied to the roller gap. It is known that such high-pressure roller presses contain a feeding device for the crushed material, which is adjusted to change the input flow of the crushed material, thereby maintaining a constant accumulation cone structure in the space between the two opposing rollers. However, depending on the type and strength of the crushed material, applying material to the roller gap in this way is insufficient to ensure vibration-free operation of the high-pressure roller press rollers and to achieve continuous operation of the entire crusher as a high-pressure roller press. Simply adjusting the accumulation cone in the space between the two opposing rollers is not always sufficient to homogenize the uneven particle distribution and air inclusions in the crushed material.

[0008] German utility model DE202009014079U1 proposes incorporating vibratory bars in the feeding device near the compression zone of the compacted material to be crushed, similar to how vibratory bars are known as concrete vibrators in concrete pouring technology. These vibratory bars remove air from the compacted material through fluidization, thereby achieving uniform operation. However, in actual operation, these vibratory bars are unsuitable for the rough environment of high-pressure roller presses. The compacted material wears down these vibratory bars too quickly, or even breaks them. The lifespan of the concrete vibrator or metal rod placed under vibration by means of a concrete vibrator is insufficient to ensure sufficiently long, uninterrupted operation of the high-pressure roller press.

[0009] To ensure the high-pressure roller press operates even near its maximum load and to maximize compaction efficiency, it is crucial to reliably eliminate excessive overload on the roller surface in the form of excessively high inter-roller pressure. Otherwise, under other conditions, i.e., operation within the overload range, surface cracking may occur on the roller surface, resulting in the loss of the protective surface layer at the cracked area. Due to surface cracking, uniform operation of the high-pressure roller press becomes impossible. The roller inevitably switches to impact-type operation because the inter-roller pressure drops and then rises sharply as the cracked surface area moves away from the inter-roller gap.

[0010] For a high-pressure roller press to operate ideally, it is important that the pressure in the roller gap remains as constant as possible over time. To this end, German document DE102011018705A1 teaches that the hydraulic system maintaining the pressure in the roller gap should be adjusted according to the vibration of the high-pressure roller press. This adjustment results in quiet and uniform operation of the high-pressure roller press. Summary of the Invention

[0011] This invention focuses on the pressure distribution along the roll gap from its center to its ends. By opening the roll gap to both sides, a flow of the compacted material occurs within the compression zone, which begins slightly above the roll gap and terminates within it. This flow causes the material to move from the center of the roll gap to its ends. Because the compacted material at each end of the roll gap flows out, it follows the pressure drop within the gap and thereby avoids compression.

[0012] Even with uniform feeding from above into the roll gap via a feeding device, the previously described and undesirable pressure drop from the center to both ends of the roll gap cannot be completely eliminated. As a result of this pressure drop, the pressure at the center of the roll gap is greater. The floating roll in the high-pressure roll press thus tends to oscillate around the pressure point at the center of the roll gap about the vertical axis, with an oscillation frequency of 0.1 Hz or less. The roll gap thus intermittently becomes less uniform in width, instead forming a wedge-like shape, with the greatest roll gap pressure occurring at the center of the rolling roll. Consequently, the rolling roll wears down over prolonged operation, causing the cylindrical rolling roll to transform into a waisted shape. Such a deformed rolling roll is unusable for further use.

[0013] Therefore, the objective of this invention is to make the pressure distribution along the roller gap uniform.

[0014] The objective according to the invention is achieved by having each sidewall equipped with a vibration device that subjects the sidewall to mechanical oscillation. Other advantageous designs are given in dependent embodiments of embodiment 1.

[0015] According to the invention, the sidewalls of the closed roller gap of the high-pressure roller press are subjected to mechanical oscillation by a vibration device. This mechanical oscillation fluidizes the material being compacted, thereby facilitating passage through the gap and resulting in a uniform increase in the roller gap pressure at the ends of the gap. The product of the actual compression zone height and the roller gap length, and the quotient of this product with the contact pressure surface (i.e., the height of the compression zone over the roller gap), represents the roller gap pressure. Therefore, the roller gap pressure decreases in the center of the gap and increases at each end. Consequently, the roller gap pressure is averaged over the length of the gap. This pressure averaging prevents the floating rollers from oscillating, i.e., from rotating with an amplitude of less than one degree around the vertical axis. Without oscillation, the high-pressure roller press operates with constant efficiency for a longer period. The wear of the rollers is also averaged, preventing the formation of noticeable waists caused by roller wear.

[0016] The energy input of the vibrating device to the compacted material is measured advantageously when the vibrating device operates at a frequency between 10 Hz and 150 Hz, preferably between 10 Hz and 60 Hz, and the magnitude is within 0.1 kJ / m.3 and 10kJ / m 3 The energy input between the two is introduced into the compacted material, preferably with a particle size of 0.1 kJ / m. 3 and 1.0 kJ / m 3 Energy input is introduced into the compacted material. The necessary design for this can be determined through simple experimental measurements. The energy input depends on the exact geometry of the sidewalls, and vibration will produce a unique waveform for the existing geometry. This waveform, in turn, indicates where energy will be input into the compacted material. Simple experiments are necessary to measure current consumption and mass flow, which can be determined by weighing the passing compacted material.

[0017] Operation has proven that the optimal energy input is present. This allows for an advantageous configuration where the vibration device has an adjustment mechanism or is connected to such a mechanism, which adjusts the vibration intensity based on the energy consumed for operation; wherein increased energy consumption leads to a decrease in vibration intensity, and decreased energy consumption leads to an increase in vibration intensity. This adjustment strategy avoids the sidewalls excessively affecting compaction performance and causing damage to themselves.

[0018] The adjustment strategy may also include adjustments based on the energy consumption of the roller drive. It can be specified that the adjustment device additionally or optionally adjusts based on the energy consumption of the roller drive, wherein increased energy consumption of the roller drive leads to a decrease in vibration intensity, and decreased energy consumption leads to an increase in vibration intensity. This adjustment strategy takes into account the fact that when fluidization occurs in the compacted material, the average pressure in the roller gap increases, and high drive power of the compaction rollers is necessary. However, operation with high drive power is not necessarily the most energy-efficient operation.

[0019] Finally, adjustments can be made additionally or optionally. It can be specified that the vibration device is additionally adjusted according to the gap width of the roll gap, wherein an increased gap width results in an increased vibration intensity, and a decreased gap width results in a decreased vibration intensity. This adjustment strategy takes into account the observable effect that the roll gap expands when it is overfilled. Fluidization of the compacted material helps to eliminate short-term overfilling effects.

[0020] Another additional or optional adjustment strategy may include adjusting the vibration device according to the tendency of the floating roller to rotate about a vertical axis, wherein the vibration intensity increases with increasing oscillation frequency of the floating roller and vice versa. This adjustment strategy includes preventing the floating roller from oscillating at less than one degree, wherein the oscillation occurs at a frequency of less than 0.1 Hz. More specifically, this adjustment strategy, compared to the aforementioned adjustment strategies, involves slowly changing parameters over a longer adjustment period. To measure the oscillation motion, position sensors can be used on the bearings, measuring the relative distance between the roller axes of the two shafts at both ends of the roller, and storing statistical analysis of the oscillation motion over a relatively long time period between 1 minute and 10 minutes.

[0021] It is also possible to use the vibration device immediately. For this purpose, a manual activation device for the vibration device can be specified. Thus, when it is determined that there is overfilling in the roller gap, the operator operates the activation device. Attached Figure Description

[0022] The invention is further illustrated with reference to the following figures. Wherein:

[0023] Figure 1 A sketch of the high-pressure roller press according to the present invention is shown in a side view.

[0024] Figure 2 The top view shows the gap between the rollers covered by the material being crushed in a high-pressure roller press without sidewalls, viewed from the perspective of the rollers.

[0025] Figure 3 A top view shows the gap between the rollers covering the material being crushed in a high-pressure roller press with sidewalls according to the prior art.

[0026] Figure 4 A top view shows the gap between the rollers covering the material being crushed in the high-pressure roller press according to the present invention. Detailed Implementation

[0027] The foregoing description of the solution according to the invention thus includes, in particular, various combinations of features defined by the subsequently numbered embodiments:

[0028] 1. A high-pressure roller press (100) for crushing brittle crushed material (M), comprising:

[0029] - At least two rollers (110, 120) arranged side by side and rotating in opposite directions, with a roller gap (W) between the rollers, wherein the first roller (110) is a fixed roller and the second roller (120) is a floating roller.

[0030] - Each of the two ends of the roller gap (W) has a sidewall (150, 150'),

[0031] Each of the sidewalls (150, 150') has a vibration device (160) that places each of the sidewalls (150, 150') in mechanical oscillation.

[0032] 2. The high-pressure roller press according to embodiment 1,

[0033] The vibration device (160) operates at a frequency between 10Hz and 150Hz, preferably between 10Hz and 60Hz, and has a magnitude of 0.1kJ / m. 3 and 10kJ / m 3 The energy input between the two is introduced into the compacted material (M), preferably with a particle size of 0.1 kJ / m. 3 and 1.0 kJ / m 3 The energy input between them is introduced into the compacted material (M).

[0034] 3. The high-pressure roller press according to any one of embodiments 1 or 2,

[0035] The vibration device (160) includes an adjustment device (170) that adjusts the vibration intensity based on the energy consumed for operation, wherein increased energy consumption leads to a decrease in vibration intensity and decreased energy consumption leads to an increase in vibration intensity.

[0036] 4. The high-pressure roller press according to embodiment 3,

[0037] The adjustment device (170) is further adjusted according to the energy consumption of the roller drive unit, wherein the increased energy consumption of the roller drive unit leads to a decrease in vibration intensity, and the decreased energy consumption leads to an increase in vibration intensity.

[0038] 5. The high-pressure roller press according to any one of embodiments 3 or 4,

[0039] The vibration device (160) is additionally adjusted according to the gap width of the roller gap (W), wherein an increased gap width results in an increased vibration intensity, and a decreased gap width results in a decreased vibration intensity.

[0040] 6. The high-pressure roller press according to any one of embodiments 3 to 5,

[0041] The vibration device (160) is additionally adjusted according to the tendency of the floating roller (120) to rotate about the vertical axis (A), wherein the vibration intensity increases as the rotational oscillation frequency of the floating roller (120) increases and vice versa.

[0042] 7. The high-pressure roller press according to any one of embodiments 1 to 6,

[0043] The device includes a manual activation device for the vibration device (160).

[0044] Figure 1 A side view sketch of a high-pressure roller press 100 according to the invention is shown. The high-pressure roller press 100 according to the invention is used to crush brittle crushed material M and has at least two rollers 110 and 120 arranged side-by-side and rotating in opposite directions. A roller gap W is formed between the two rollers 110 and 120, through which the crushed material M is guided without relative sliding of the rollers 110 and 120 or with only slight relative sliding. The first roller 110 is a fixed roller, and the second roller 120 is a floating roller. The floating roller 120 has two degrees of freedom of movement. The floating roller can move away from the fixed roller 110 when the roller gap W widens, and can also rotate about a vertical axis A with an amplitude of less than one degree. To prevent the crushed material M from flowing towards and falling out of the openings of the roller gap W in the plane of the drawing, sidewalls 150 and 150' are provided opposite the two openings of the roller gap W. According to the invention, each sidewall has a vibration device that places each sidewall 150, 150' into mechanical oscillation. The mechanical oscillation is transmitted to the compacted material M located near the respective ends of the roll gap W, the compacted material flowing in or over the compression zone. The oscillation fluidizes the compacted material M, thereby facilitating passage through the roll gap W at a pressure of 50 MPa or greater.

[0045] Figure 2 A top view shows the roller gap W covered by the compacted material M in a high-pressure roller press 100 without sidewalls 150, 150', viewed from the perspective of the compaction rollers 110, 120. The compacted material M is placed on the roller gap W as a dumping material and covers the roller gap W. Arrows are drawn on the compacted material M, indicating the approximate flow movement of the compacted material M on the roller gap W until it enters the compression zone. The actual movement of the compacted material particles is not necessarily the length of the arrow, but the actual movement of the compacted material particles can also occur along a small portion of the arrow path. Figure 2Near the right side of the sketch is a diagram showing the possible pressure p in the roll gap W along position x. In this open high-pressure roll press, the pressure drop in the roll gap W towards each end is very large, resulting in a sharp drop in pressure in the roll gap W from greater than 50 MPa in the roll end region. As a result, effective fragmentation no longer occurs in the roll gap end region by compression.

[0046] Figure 3 This is a top view of the roll gap W covered by the material being crushed, of a high-pressure roller press 100 with static sidewalls 150, 150', shown here from the perspective of looking towards the crushing rollers 110, 120. The pressure drop in the roll gap W to the roller shoulder, i.e., the pressure drop in the region at the end of the roll gap, is compared to... Figure 1 The structure is significantly reduced, but it still exists. This effect is called the "edge region effect." This effect is partly caused by friction on the sidewalls. The sidewalls create flow barriers, and the resulting friction increases with increasing extrusion pressure because the reaction force on the sidewall surface increases. The stronger the material from the gap is squeezed against the sidewalls, the greater the coefficient of friction, and therefore less material flows into the edge region of the gap. As a result, the compression of the material bed decreases, and the resulting pressure in the edge region decreases accordingly. More precisely, this causes the pressure to be distributed approximately in a bell shape along the roller gap.

[0047] Figure 4 This is a top view of the roller gap W covered by the material being crushed, 120, of a high-pressure roller press 100 according to the invention, shown here from the perspective of the crushing rollers 110 and 120, wherein the high-pressure roller press has vibrating sidewalls 150 and 150'. The vibration is generated by a vibration device 160, and the intensity of the vibration is adjusted by an adjustment device 170 under certain conditions. Through the vibration of the sidewalls 150 and 150' respectively, pressure is maintained at each end of the roller gap W because the material being crushed, 120, can flow unimpeded into the roller gap W. The vibration helps the material being crushed, 120, pass through the roller gap W. The unimpeded flow of material along the entire width of the rollers results in a uniform pressure profile and uniform wear of the crushing rollers 110 and 120, thus preventing the formation of such a pronounced waistline.

[0048] List of reference numerals

[0049] 100 High Pressure Roller Press

[0050] 110 rolling roller

[0051] 120 rolling roller

[0052] 150 sidewall

[0053] 150′ sidewall

[0054] 160 vibration device

[0055] 160' Vibration Device

[0056] 170 Adjustment Device

[0057] Axis A

[0058] M compacted material

[0059] W roll gap

Claims

1. High-pressure roller mill (100) for comminuting brittle roll stock (M), having a first roll (110) which is a fixed roll and a second roll (120) which is a floating roll, - a roller gap (W) between the rolls, - a side wall (150, 150') on each of the two ends of the roller gap (W), characterized in that the side wall (150, 150') on each of the two ends of the roller gap (W) has a vibration device (160) which places the side wall (150, 150') in mechanical oscillation. - at least two, side by side arranged, counter-rotating rolling cylinders (110, 120) between which an inter-roller gap (W) is configured, wherein 2. High-pressure roller mill according to claim 1, characterized in that the vibration device (160) is designed as a vibration exciter.

3. High-pressure roller mill according to claim 1, characterized in that the vibration device (160) is designed as a vibration generator.

4. High-pressure roller mill according to any one of claims 1 to 3, characterized in that the vibration device (160) has an adjusting device (170) which adjusts the vibration intensity depending on the energy consumed for the operation, wherein an increased energy consumption leads to a decrease in the vibration intensity and a decreased energy consumption leads to an increase in the vibration intensity.

5. High-pressure roller mill according to claim 4, characterized in that the adjusting device (170) additionally adjusts depending on the energy consumption of the roller drive, wherein an increased energy consumption of the roller drive leads to a decrease in the vibration intensity and a decreased energy consumption leads to an increase in the vibration intensity.

6. High-pressure roller mill according to claim 4, characterized in that the vibration device (160) is additionally adjusted depending on the gap width of the roller gap (W), wherein an increased gap width leads to an increase in the vibration intensity and a decreased gap width leads to a decrease in the vibration intensity. The vibrating device (160) works at a frequency between 10 Hz and 150 Hz and introduces into the rolled material (M) an energy input of size between 0.1 kJ / m 3 and 10 kJ / m 3 .

7. High-pressure roller mill according to claim 5, characterized in that the vibration device (160) is additionally adjusted depending on the gap width of the roller gap (W), wherein an increased gap width leads to an increase in the vibration intensity and a decreased gap width leads to a decrease in the vibration intensity.

8. High-pressure roller mill according to claim 4, characterized in that the vibration device (160) is additionally adjusted depending on the tendency of the floating roll (120) to rotate about a vertical axis (A), wherein the vibration intensity increases with an increase in the rotational oscillation frequency of the floating roll (120) and vice versa. The vibration device (160) is operated at a frequency between 10 Hz and 60 Hz and introduces an energy input of between 0.1 kJ / m 3 and 1.0 kJ / m 3 into the rolled material (M).

9. High-pressure roller mill according to any one of claims 5 to 7, characterized in that the vibration device (160) is additionally adjusted depending on the tendency of the floating roll (120) to rotate about a vertical axis (A), wherein the vibration intensity increases with an increase in the rotational oscillation frequency of the floating roll (120) and vice versa.

10. High-pressure roller mill according to any one of claims 1 to 3, characterized in that a manual activation device for the vibration device (160) is provided. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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