JPH0710357B2 - Scavenging type crusher - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a scavenging-type crushing device according to the preamble of claim 1.

Such a scavenging type crushing device is disclosed in, for example,
It is known from 2019005 or European Patent 0173065A2 and is shown in FIG. 1 of the accompanying drawings of the present application.

In order to explain the problems that occur in the conventional scavenging type crushing device, the scavenging type crushing device 1 will be briefly described below together with its operation together with the essential assemblies and components.

The scavenging crusher 1 rests on a foundation and is usually hermetically enclosed by a casing 2. This crushing device includes a lower roller mill, and an upper part of a classifier 11 is installed over the roller mill. A grinding pan or grinding bowl 3 as part of a roller mill is rotated by a drive 4. The material to be ground is supplied to the grinding pan 3 from above or from the side and is ground between the grinding roller 9 and the pan 3 which are elastically pressed. The grinding roller 9 does not have a separate drive, but is instead rotated only by frictional engagement with the grinding pan 3 or with the grinding material between the grinding roller and the grinding pan. Air flows in through the supply channel 6, and the vane ring 16 sends the mixture of oversized and undersized material thrown out of the pan 3 after crushing up through the roller 9 to the vicinity of the classifier 11. A rotor driven by a driving machine 14 in response to the rotating and rising flow of the air / fine powder mixture 13.
12 rejects the oversized material, as a result of which the oversized material falls on the grinding pan 3 in the vicinity of the so-called vortex sink or vortex sump 8 with a partial air flow. The undersize material exits the classifier 11 via the powder outlet 15.

The normal flow ratio of the air / fines mixture is shown in FIG. 1 by the dashed lines as streamlines. A vortex sump 8 is formed in the center of the roller mill below the classifier rotor 12, not only is the crushed material particles carried in the vortex sump, but air or gas or these Both are returned to the grinding pan 3. This air / fines mixture is drawn in by means of a grinding pan 3 and is rolled, only air escapes to the outside.

Obviously, the flow ratio in the inner zone 7 of the scavenging mill 1 depends to a great extent on the desired fineness of production. A standard design of scavenging mill, such as is commonly used for cement-raw-coal milling, averages about 10
A fine powder with a fineness of -30% R DIN O.09 is produced.

If the scavenging mill is to be used to produce fines that are considerably finer than 10% R DIN O.09, the oversized material rejected by the classifier 11 will also be considerably finer. In air, the buoyancy of very fine powders is much greater than that of coarse powders, so crush pans of oversized material 3
The ratio of gravity to return to is rather small. This means that a "fines cloud" through which a very large amount of air has fallen, or returned, to the grinding pan. As a result of the very limited internal friction, from a physical point of view, this fine cloud is virtually comparable to a fluid.

A problem that arises with such conventional scavenging crushers is that a fairly air crushed bed is obtained at the crushing pan and carried by rotation of the pan to the upstream side of the crushing roller 9. However, these grinding rollers 9 can only be attracted to this air-rich grinding bed to a limited extent. As a result, the air-rich crushed material is first dammed in front of the crushing rollers and air is removed from the dust / air mixture. Therefore, in front of the grinding roller, a continuously increasing dust wave is formed, which is comparable to a warhead wave.

In the conventionally known structure, since the crushing roller 9 is driven only by the friction between the crushing material and the crushing pan or the direct friction between the crushing pan, this conventionally known frictional force drive does not work or, even if it works, considerably. It is inappropriate.
This is because the connecting medium, which behaves like a dust wave, has properties similar to a fluid as a grinding bed rich in air. As a result, the speed of the grinding roller decreases,
Alternatively, the crushing roller stops completely.

Only when sufficient air has been removed from the dust / air mixture of the air-rich grinding bed will the coupling medium be sufficiently stable to drive and hold the grinding rollers by frictional engagement. However, when such a slow accumulation of growing pulverized waves rapidly increases in the form of a fine powder wedge on the upstream side of the crushing roller, the crushing bed is rapidly pulled and continuously pulled below the elastic crushing roller 9. Further defects occur. As a result of the physical conditions,
Grinding rollers, which slow down or stop, for example, must be subjected to the action of accumulated fine dust wedges and accelerated. However, this means that very high drive energy is instantaneously required. This is because the inertia of the large roller must be overcome.

The above operating state causes slipping and other attachment phenomenon on the crushing roller,
This causes significant vibrations in the roller mill. Apart from the mechanical damage due to this slippage / adhesion phenomenon in the scavenging type pulverizer, there is also a reduction in mill output in the case of discontinuous operation of the roller mill.

SUMMARY OF THE INVENTION As a result of the deficiencies that occur in the prior art,
Achieves high efficiency in terms of mill output, especially when demanding a high degree of fineness for the material to be crushed, yet keeps the work sequence as uniform as possible and is abrupt, i.e. impact, in terms of power consumption or from a mechanical point of view The purpose of this is to design a scavenging type pulverizer so as to effectively reduce specific stress.

According to the invention, this problem is claimed in claim 1.
It is solved by the feature of the feature description part of.

The basic principle is to stop driving the scavenging plate or the crushing disk of the scavenging crusher with a single drive and to drive the individual crushing rollers in rotation.

At first glance, this seems to require extra equipment costs with higher energy demands. However, the present invention avoids sudden stresses that would increase mechanical wear through continuous operation of the roller mill. This also applies to power demand, which allows more uniform power consumption and eliminates the need to design the device for peak load, unlike in the past.

Therefore, the grinding rollers are driven by a separate corresponding drive means, for example an electric motor, at a speed at least corresponding to the logical speed in the case of frictional engagement of the grinding pan or bowl with the corresponding grinding roller. By this theoretical speed is meant here the speed that occurs when the grinding roller is continuously rotated with respect to a conventional grinding bed.
The speed of the grinding roller should be somewhat higher than this logical speed. As a result, slipping or sticking of the grinding roller to the grinding bed or the pan is completely eliminated, and effective fine grinding of the material to be ground can be performed.

If possible, the speed of the grinding roller can be adjusted steplessly so that it can be adjusted according to the desired fineness of the grinding material, the grinding bed thickness, the load condition of the roller mill or the running behavior. . As a result, the speed that is forced on the crushing roller to prevent dust waves from occurring upstream of the crushing roller is an essential feature of the invention. Furthermore, the drive torque T per crushing roller is It must be equal to or less than the value obtained from the quotient of the number of torque T _{gliding pans} and grinding rollers.

That is, when a plurality of grinding rollers, the driving torque of O~T _rollers each grinding roller is added, T _rollers
Is the maximum driving torque of one grinding roller, and T
_{If the grinding} pan is the driving torque for the grinding pan, It is preferable that

In view of these two aspects, the invention makes it possible in all cases that the rotary drive of the milling roller gives an effect comparable to the pure friction drive as occurs in conventional milling devices.

Such scavenging mills are often airtightly enclosed and the corresponding milling rollers are incorporated into their respective rocking levers, thus providing a separate drive for a particular milling roller, in any form, for example motorized. , Mechanically driven, or
It is advisable to provide drive means, which may be of the hydraulic drive type, on the side remote from the grinding roller. It is particularly suitable to mount the driving means, such as an electric motor, on the grinding part casing without connecting it. The driving means may be mounted in the casing and may be mounted in a place other than the casing. It is important that the drive shaft of the drive means is not connected to the drive shaft for the grinding roller.

There are two basic alternatives to the individual drive of the grinding rollers. As a first alternative, a grinding roller having a fixed roller shaft is rotatably mounted on a swing lever of a specific roller unit. Next, the drive means is appropriately fixed to the swing lever. As a result, rollers with various grinding bed heights
Due to the vibration of the unit, a separate correction means is not necessary.
As a second alternative, a stationary hollow shaft is installed in the rocking lever. The grinding roller is rotatably held at the inner end of the hollow shaft by anti-friction bearings, for example axial and radial bearings. The actual driving is carried out by means of a drive shaft which passes through the hollow shaft, which drives the required torque on the grinding roller via a closing or terminating device.

At the opposite end, this drive shaft is connected to a drive means, in particular a cardan-type radial and axial adjustment of the complete shaft is possible via an intermediate member. The electric motor that serves as the driving means may be directly fixed to the swing lever, or may be attached to the outside of the casing without being connected.

In both of these alternatives, spring means are provided which engage at least the rocking lever and are supported on the fixed part of the crushing device to exert a roller contact pressure on the material to be crushed.

As a result of mounting the hollow shaft or the roller shaft corresponding to the rocking lever, it becomes possible to directly mount the shaft in the casing of the crushing device.

Hereinafter, the present invention will be described in more detail with reference to two embodiments illustrated in the accompanying drawings.

The scavenging type crushing apparatus 1 shown in FIG. 1 was explained at the beginning in order to point out the defects and problems of the prior art. However, the individual assemblies and components of this scavenging type crushing apparatus are the same as those of the invention. Some are identical and are therefore given the same reference numerals.

By the way, in order to overcome the defects of the conventional crushing device such as the slipping / attachment phenomenon and the mill vibration, in the present invention, the crushing roller is driven in addition to the driving of the crushing pan or the crushing bowl 3. Correspondingly, the speed and torque are also adjusted so that the grinding roller is independently rotated without forming a bowing wave of the material on the upstream side of the grinding roller. The rotation directions of the grinding roller and the grinding pan in the grinding gap or bed are the same.

Description of the Preferred Embodiment The embodiment schematically shown in FIG. 2 is the first alternative of the drive for the grinding roller 20. Grinding roller 20 and swing lever 25
The roller unit consisting of is fixed on its own basic block on the casing or bearing housing 35,
It can be rotated around the rocking lever point 34. The basic principle of this driving machine is to fix the hollow shaft 23 in the bush 27 of the rocking lever 25 by using, for example, a clamp device 36. The grinding roller is rotatably mounted on the roller side, i.e. on the right end of the hollow shaft in FIG. 2, on said hollow shaft 23 by means of a radial bearing 32 and a tilt bearing 33. Crushing roller 20
(In this example, a roller body 21 on the inner side in the radial direction and a roller shell 22 on the outer side of the truncated cone) is guided in the hollow shaft 23, and with a corresponding torque by a drive shaft 24 optionally mounted. Driven. The roller shell 22, in this example, is rigidly but replaceably secured to the roller body 21 by bolts 48 and clamp rings 49. The right side of the roller unit shown in FIG. 2 is closed by a cap-like closure or termination device 44. This closure device 44 and its fasteners
50 is mainly used for transmitting the drive torque from the inner drive shaft 24 to the actual grinding roller via the joint member 45 and its rigid connection portion 46. This closing device 44 serves as a dustproof airtight seal for the inner shaft and also as a bearing block for the tilt bearing 33.

On the drive side, the inner drive shaft 24 is connected by a coupling shaft 43 to a motor 26, which is schematically illustrated, for example a driven shaft 42 of an electric motor. The motor 26 is a stop plate fixed to the swing lever 25.
Fastened to 39 by fasteners 41. Driven shaft 42 of motor 26
Project into the hollow shaft 23 through the corresponding openings 40.
The shaft member is designed to be axially adjustable in the direction of the longitudinal axis of the hollow shaft and also radially adjustable. It can be used as a universal joint or a cardan joint joint member.

For illustration purposes, it is shown how the roller unit is acted upon by the pressure spring 29 via the flange 28. The spring 29 is supported as a bearing block with respect to the fixed portion 30.

Thus, in the embodiment shown in FIG. 2, the grinding pan 3 rotates independently about its axis of rotation 47 and is equipped with its own drive as well as the grinding roller unit, so that the grinding roller The individual drive prevents the above-mentioned defects.

The dimensions of the bore 31 of the hollow shaft 23 are determined by the outer circumference of the coupling member or drive shaft 24 and the stability required to absorb the load and rotation of the rollers.

A second alternative drive for the grinding roller 55 is shown schematically in FIG. 3 in a partially axial section, in which the roller shaft 56 is connected to the grinding roller 55. The roller shaft is rotatably mounted in the bushing 52 of the lock lever by a bearing 53 that absorbs axial and radial forces, for example. It is driven by a drive mechanism 58 having a corresponding drive shaft 57. As in the previous embodiment, the rocker lever 25 is mounted with respect to the bearing housing 35 by a rocker lever joint 34. Swing lever 25 has axis 47
Grinding roller 55 for grinding pan 5 rotating around
Allow the corrective exercise of. The rocking levers also serve to swing out the entire roller unit from the corresponding grinder casing. As with the previous embodiment, the pressure spring 29
For example, it is supported on a fixed part 30 of the casing, which acts on the grinding roller 55 via a flange 28 and a rocking lever 58.

The drive means 58 is fixed to the swing lever 25 by the motor holding means 54 shown in FIG. Like the drive mechanism 58, if possible, the bearings of the roller shaft 56 are housed in a dust-proof, airtight manner with respect to the interior 7 of the crusher. The end on the roller side is formed by a round roller cap 69 in this embodiment.

The drive alternatives shown in FIGS. 2 and 3 can be used with the vacuum operated mill 1 of FIG. In this mill 1, the rocking lever 10 is installed essentially outside the casing 2 and, as a result, the drive 26, as shown in FIGS.
It is also possible to fix 58 to the swing levers 25, 27, 52 and the swing lever 10 directly. In this case, the driving machine is, for example,
Rotate around joint 34 with the corresponding rocking lever.

FIG. 4 shows a scavenging mill according to the invention, the assembly corresponding to the prior art being designated by the same reference numbers as in FIG. The scavenging mill 60 of FIG. 4 has in the roller mill area a milling pan 61 having a dome-shaped central projection 62 for distributing the milling material fed or circulated along the milling path. The crushed material is supplied by a material supply channel 64 which extends through the classifier 11 from the center to the bottom. A hollow rotor drive shaft 65 of the drive unit of the rotor 12 is rotatably provided around this flow path.

The drive mechanism for the crushing roller 20 on the left side substantially corresponds to the alternative shown in FIG. 2 and the torque is applied to the crushing roller 20 by means of a drive shaft 24 extending in the hollow shaft. Motors 26 (mounted on outer casing 2 by retaining struts 41) individually drive grinding rollers 20 via driven shafts 42. Driven shaft
42 projects through an opening 63 in the outer casing 2 of the crusher. The passage opening for the drive shaft and the mounting support, which are not explicitly shown in the figure, are designed to be gas-tight and gas-tight.

In this scavenging type crushing device 60, since the rocking levers 25 and 27 are arranged inside the casing 2, the driving machine cannot be fixed directly to the back surface of the rocking lever 27. The drive 26 must be externally fixed to the mill casing 2 by means of mounting supports 41. The pivoting movement of the rollers is thus corrected by the drive shaft 24 via a universal adjustment, which can be provided especially by a universal joint.

By individually driving each crushing roller 20, the material to be crushed is prevented from being dammed on the upstream side of the roller, resulting in noise generation during the operation of the roller mill and causing premature wear. Sliding that causes
The attachment phenomenon disappears. The drive unit may also be designed to reduce maximum power because it avoids the type of sudden stress that was encountered in the prior art. In this way, it is possible to significantly improve the yield even if the material to be ground requires a high fineness.

[Brief description of drawings]

FIG. 1 is a front view of a scavenging type pulverizer according to the prior art for explaining a flow state. FIG. 2 is a schematic axial cross-sectional view of a first alternative example of the crushing roller driving machine, showing the roller unit together with the rocking lever. FIG. 3 is a partial sectional view of a second alternative example of the crushing roller. FIG. 4 is a front view of the scavenging type crushing device of the present invention.
FIG. 4 is a diagram showing a state in which the drive substitute example of FIG. 2 is used, while leaving the reference numerals and the assembly of the figure. In the drawing, 20 ... crushing roller, 21 ... roller body, 22
...... Roller shell, 23 …… Hollow shaft, 24 …… Drive shaft, 25
...... Rotating lever, 29 ...... Spring, 35 ...... Bearing housing, 42 ...... Drive shaft, 43 ...... Joint shaft, 44 ...... Closing device,
45 …… Coupling member, 52 …… Bushing, 55 …… Grinding roller, 56 …… Roller shaft, 58 …… Driving means, 60 …… Scavenging type grinding device, 61 …… Grinding pan, 64 …… Material supply flow path , 65 ……
Drive shaft

Claims (10)

[Claims] 1. A roller mill having at least one crushing roller in a stationary state, wherein the crushing roller can be elastically pressed against a rotating crushing pan, and an integrated classifier is arranged above the roller mill. A scavenging type crushing device, in which the crushing material / air mixture is essentially supplied to the crushing pan and the crushing roller from the center of the roller mill. 22 and 55) also have separate drive means (26, 58) by which the crushing rollers (20, 55) with or without crushed material have a crushing pan (3) and a crushing roller (20, 55).
55) is forced to rotate in the same direction as the grinding pan (3) at a speed at least equal to the theoretical speed during frictional engagement or higher than this theoretical speed, and has several grinding rollers and each grinding Rollers (20, 55)
The drive torque of the O-T _roller is applied to the The scavenging-type pulverizing device, wherein T- _{grinding pan} is the driving torque of the pulverizing pan and T- _roller is the maximum driving torque of one pulverizing roller. 2. The scavenging-type crushing device according to claim 1, wherein the speed of the crushing rollers (20, 55) changes steplessly. 3. A scavenging pulverizer according to claim 2, characterized in that the speed of the crushing rollers (22, 55) is adjustable as a function of the fineness of the crushed material. 4. The scavenging type crushing apparatus according to claim 1, wherein each crushing roller (20) is mounted on a fixed hollow shaft (23), and the crushing roller (20) is provided in the shaft. Drive shaft (24, 4
2, 43, 45) are arranged, and the drive shaft is driven on the side remote from the crushing roller (20). 5. The scavenging-type crushing device according to claim 4, wherein the drive shafts (24, 42, 43, 45) are adjustable in the radial direction. 6. The scavenging-type crushing device according to claim 4, wherein the drive shafts (24, 42, 43, 45) can be adjusted in the axial direction. 7. The scavenging type crushing apparatus according to claim 4, wherein a closing device (44) is provided on a side of the hollow shaft (23) facing the center (8) of the roller mill, and the closing device (44) is crushed. A scavenging type crushing device, characterized in that the hollow shaft (23) is sealed to the inside (7) of the device (6) and the torque is transmitted to the crushing roller (20). 8. The scavenging type crushing apparatus according to claim 1, further comprising a casing, several crushing rollers, and a swing lever combined with each crushing roller, wherein each crushing roller (55) has a roller shaft ( 56), the roller shaft is rotatably mounted in the casing (2), and the roller shaft (56) is fixed to the driving means (58). Crushing equipment. 9. The scavenging type crushing apparatus according to claim 1, further comprising a casing, several crushing rollers, and a swing lever combined with each crushing roller, wherein each crushing roller (55) has a roller shaft ( 56), this roller shaft is rotatably mounted on the rocking lever combined with the grinding roller (55), and this roller shaft (56) is fixed to the drive means (58). A scavenging type crushing device. 10. The scavenging-type crushing apparatus according to claim 4, further comprising a casing, and driving means (26, 58) provided so as not to be connected on the casing (2). apparatus.