JPH0263559A - Scavenging type crushing apparatus - Google Patents

Abstract

PURPOSE: To achieve the high efficiency by forcibly rotary-driving a grinding roller by a driving means at a speed at least coincident with a theoretical speed when the grinding roller is engaged with a grinding pan by friction in the same direction as the grinding pan regardless as to whether or not a material to be ground is present. CONSTITUTION: A roller mill having at least one the grinding roller 20 in the standstill state is provided, allowing the grinding roller 20 to be elastically pressed against the rotating grinding pan 61. Further, an integrated classifier 11 is arranged above the roller mill, thereby allowing the material to be ground and an air mixture to be substantially supplied to the grinding pan 61 and the grinding roller 20 from the center of the roller mill. Then, the grinding roller 20, too, is provided with a driving means 26 being a separate body in addition to the grinding pan 61. By this driving means 26, the grinding roller 20 is forcibly rotary-driven at a speed at least coincident with a theoretical speed when the grinding roller 20 is engaged with the grinding pan 61 by friction or a higher speed than this theoretical speed in the same direction as the grinding pan 61 regardless as to whether or not the material to be ground is present.

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION The present invention relates to an 8-air crusher as set forth in the preamble of claim 1 of the appended claims.

Such a scavenging crushing device is disclosed in, for example, German Patent No. 2019005 or European Patent No. 4. license 017306
5A2 and is shown in FIG. 1 of the accompanying drawings.

In order to explain the problems that occur in the conventional scavenging type crushing apparatus, the scavenging type crushing apparatus 1 will be described below along with its operation, essential sets, and constituent elements.

The scavenging crusher+ rests on a foundation and is usually enclosed in a gas-tight manner by a casing 2.

This crushing device includes a lower roller mill, and an integrated classifier 11 is installed above the roller mill. It is rotated by a grinding pan or grinding bowl 3 or a drive 4 as part of a roller mill. The material to be crushed is fed into the crushing pan 3 from above or from the side and is crushed between the pan 3 and the crushing roller 9 which is elastically pressed against the crushing roller 9. The grinding roller 9 has no separate drive and 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 enters through the feed channel 6 and sends the mixture of oversized and undersized materials thrown out from the pan 3 after vane ring 16 or crushing upwards through rollers 9 to the vicinity of the classifier 11. Air/fine powder mixture 1
In response to the flow from rotating to upward R in step 3, the driver 14
The rotor 12 driven by the rotor 12 rejects the oversized material, so that it falls onto the grinding pan 3 in the vicinity of the so-called vortex sink or vortex sump 8 together with the partial air flow. The undersized material 1 exits the classifier 11 via a powder outlet 15.

The typical flow ratio of the air/fine powder mixture is shown in FIG. 1 as a streamlined dashed line. A vortex sump 8 is formed in the center of the roller mill below the classifier rotor 12, in which not only the crushed material particles are transported, but also air or gas or Both of these are returned to the grinding pan 3. This air/fine powder mixture is drawn in and rolled by the grinding pan 3, and only the air escapes.

1. As is clear, the flow ratio in the inner desired zone 7 of the scavenged grinding device 1 depends to a large extent on the desired product fineness. Typical designs of scavenging type grinding equipment, such as those used in Tingtong for cement-raw material-coal pulverization, produce fine powder with an average fineness of about 10-30% RDIN 0.09.

If the scavenging grinder is to be used to produce a finer powder significantly finer than 10% RDI No. 09, the oversized material rejected by the classifier 11 will also be significantly finer. In air, the buoyancy of very fine powders is much greater than that of coarse powders, so that the proportion of gravity that returns the oversized material to the grinding pan 3 is correspondingly smaller. This means that a very large amount of air is passed through the "fine cloud" which falls or is returned to the grinding pan. From a physical point of view, as a result of very limited internal friction,
This fine powder cloud is substantially comparable to a fluid.

The problem that arises in such a conventional scavenging type grinding device is that the grinding roller 1- obtains a large amount of air through the grinding pan and conveys it to the second side of the grinding roller 9 by the rotation of the pan.
There is a thing. However, these grinding rollers 9 are attracted to this airy grinding bed only to a limited extent. As a result, the aerated grinding material is first dammed up in front of the grinding rollers and removed from the air or dust/air mixture. Therefore, a continuously increasing dust wave is formed in front of the crushing roller, which
Comparable to head waves.

In the conventionally known structure, the grinding roller 9 is driven only by the friction between the grinding material and the grinding pan or by the direct friction with the grinding pan, so that this conventionally known friction force drive does not function or even if it does function. is also quite inappropriate.

This is because the coupling medium, which behaves like a dust wave, has fluid-like properties as an airy grinding bed. As a result, the speed of the grinding rollers decreases or
Alternatively, the grinding rollers stop completely.

Only when sufficient air has been removed from the dust/air mixture in the airy grinding bed will the coupling medium become sufficiently stable to drive and hold the grinding rollers by frictional engagement. However, if such a slow accumulation of growing fine powder waves or a sudden increase in the shape of a fine powder wedge on the upstream side of the crushing roller, the crushing blades 1 are rapidly pulled, and the crushing roller 9 is continuously strained. An additional defect of downward pulling occurs. As a result of said physical conditions, for example, a grinding roller that slows down or stops, is suddenly subjected to the action of the accumulated fines wedge and has to be accelerated. However, this means that very high drive energies are required instantaneously. This is because the inertia of the large rollers must be overcome.

The above operating conditions will cause the grinding roller to slip and stick to other particles.
This causes significant vibrations in the roller mill. Apart from the mechanical damage caused by this sliding and sticking phenomenon in the scavenging crushing equipment, there is also a reduction in the output of the mill in the case of discontinuous operation of the roller mill.

[Summary of the invention] One problem of the present invention is as a result of the defects that occur in the prior art.
Achieving high efficiency in terms of mill output, especially when a high degree of fineness is desired in the material to be ground, yet making the working sequence as homogeneous as possible and reducing sharpness in terms of power consumption or from a mechanical point of view, i.e. An object of the present invention is to design a scavenging type crushing device to effectively reduce impact stress.

According to the invention, this problem is solved by the features of the characterizing part of claim 1 of the patent claims.

The basic principle is not to drive the grinding plates or grinding discs of the scavenged grinding device with a single drive, but instead to drive the individual grinding rollers in rotation.

This appears to require extra equipment costs with apparently 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 the power demand, making the power consumption more uniform and eliminating the need to design the device for peak loads, unlike in the past.

The grinding rollers are thus driven by individual corresponding drive means, for example electric motors, at a speed that at least corresponds to the theoretical speed in the case of frictional engagement of the grinding pan or grinding bowl and the corresponding grinding roller. By theoretical speed is meant here the speed that would occur if the grinding rollers were rotated continuously with respect to a conventional grinding bed.

The speed of the grinding rollers is preferably somewhat higher than this theoretical speed. This eliminates any slippage or adhesion of the grinding rollers to the grinding bed or grinding pan, allowing effective pulverization of the material to be ground.

If possible, the speed of the crushing rollers can be adjusted steplessly, so that the desired degree of fineness of the crushed material 1 can be achieved.
It can be adjusted depending on the grinding bed thickness, the load condition of the roller mill or the operating behavior. As a result, the forced speed of the grinding rollers to prevent dust waves from forming upstream of the grinding rollers is an essential feature of the invention. Furthermore, the drive torque T per grinding roller must be equal to or smaller than the value obtained from the quotient of the grinding pan's 1~LkTg,i,day>7+r<> and the number of grinding rollers.

In other words, when a plurality of crushing rollers are provided, a driving torque of O-, -Tn- is applied to each crushing roller, and T
If n-5 is the maximum driving torque of one grinding roller, and T kwai, i, war-r (> is the driving torque of the grinding pan), it is preferable to do the following.

Taking these two aspects into account, the invention allows the rotary drive of the grinding rollers to be comparable in effect to a pure frictional drive as occurs in conventional grinding devices in all cases.

Such scavenging grinding devices are often air-tightly enclosed and incorporate a corresponding grinding roller into each oscillating lever, thus giving a separate drive for a particular grinding roller and allowing it to be of any type, e.g. electric The drive means, which may be mechanically driven or hydraulically driven, may be provided on the side remote from the grinding rollers. It is particularly suitable to mount the drive means, such as an electric motor, without being connected to the comminution part casing. The driving means may be mounted within the casing or may be mounted outside the casing. It is important that the drive shaft of the drive means is not coupled to the drive 4i1+ for the grinding rollers.

There are two basic alternatives to driving the grinding rollers individually. As a first alternative, a grinding roller with a fixed roller shaft is rotatably mounted on a rocking lever of a particular roller unit. The drive means is then suitably secured to the swing lever. As a result, separate compensation means are not required for vibrations of the roller unit due to different grinding bed heights. A second alternative is to install a stationary hollow shaft within the swinging 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 drive takes place by a drive shaft passing through the hollow shaft, which provides the necessary torque to the grinding roller via a closure or termination device.

At the opposite end, this drive shaft is connected to a drive means, which in particular allows a cardanian radial and axial adjustment of the complete shaft via an intermediate member. The electric motor serving as the drive means can be fixed directly to the rocking lever or it can be mounted on the outside of the casing without being connected. Spring means supported on the fixed portion of the roller are provided to apply roller contact pressure to the material to be ground.

As a result of equipping the swing lever with a corresponding hollow shaft or roller shaft, it is also possible to install it directly into the casing of the crushing device.

The invention will now be explained in more detail with reference to two exemplary embodiments illustrated in the accompanying drawings, in which: FIG.

Note that although the scavenging type crushing apparatus l shown in FIG. Some items are identical, so they have the same reference numerals.

However, in order to overcome the deficiencies of conventional grinding devices such as slipping/sticking phenomena and mill vibration, the present invention, in addition to driving the grinding pan or grinding bowl 3, also drives the grinding rollers. Correspondingly, the speed and torque are also adjusted to allow the grinding rollers to rotate independently without forming arching waves of material upstream of the grinding rollers. The direction of rotation of the grinding rollers and the grinding pan in the grinding gap or bed is in the same direction.

DESCRIPTION OF THE PREFERRED EMBODIMENT The embodiment shown schematically in FIG. 2 is a first alternative of the drive for the grinding roller 20. The roller unit, consisting of the grinding roller 20 and the rocking lever 25, is fixed on its own base block of the casing or bearing housing 35'' and is pivotable about the rocking lever point 34. The basic principle of this drive is, for example, the clamping device 36
The hollow shaft 23 is inserted into the bush 27 of the swing lever 25 using
The goal is to fix the The grinding roller is rotatably mounted on the hollow shaft 23 on the roller side, ie at the right end of the hollow shaft in FIG. 2, by means of a radial bearing 32 and an inclined bearing 33. Grinding roller 20 (in this example, a radially inner roller body 21 and an outer frusto-conical roller shell 22)
) is guided in a hollow shaft 23 and driven with a corresponding torque by an optionally mounted drive shaft 24.

The roller shell 22 is in this example rigidly or exchangeably fixed 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 catch 50 are primarily used to transmit the drive torque from the inner drive shaft 24 via the coupling member 45 and its rigid connection 46 to the actual grinding rollers. This closed bag f! I44 provides a dust-tight airtight seal for the inner shaft and also serves 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 schematically illustrated motor 26 , for example a driven shaft 42 of an electric motor. The motor 26 is fixed to a stop plate 39 fixed to the swing lever 25 by a fastener 41. The driven shaft 42 of the motor 26 projects into the hollow shaft 23 through a corresponding opening 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 1-1 or a cardan joint joint member.

For illustration purposes, it is shown how the roller unit is acted upon by a pressure spring 29 via the flange 28. Note that this 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, like the grinding roller unit, is provided with its own drive, so that the grinding rollers The above-mentioned defects can be prevented by individual driving.
be done.

The dimensions of the bore 31 of the hollow shaft 23 are those of the joint member or the drive shaft 2.
4 and the stability required to absorb the load and rotation of the rollers.

A second alternative embodiment of the drive for the grinding roller 55 is shown schematically in partial axial section in FIG. .

This roller shaft is, for example, connected to the bushing 5 of the locking lever by a force-absorbing bearing 53 in the axial and radial direction.
It is rotatably mounted inside 2. Corresponding drive shaft 57
The drive is performed by a drive mechanism 58 having a. As in the previous embodiment, the swing lever 25 is mounted with respect to the bearing housing 35 by a swing lever joint 34.

The swing lever 25 allows a corrective movement of the grinding roller 55 with respect to the grinding pan 5 rotating about the axis 47. The rocking lever also serves to swing out the entire roller unit from the corresponding milling device casing. As in the previous embodiment, a pressure spring 29 is supported, for example on a fixed part 30 of the casing, which is connected to the flange 28.
and acts on the crushing roller 55 via the swing lever 58.

The pulsating means 58 is fixed to the swing lever 25 by the motor holding means 54 shown in FIG. Similar to the drive mechanism 58, if possible the bearings of the roller shaft 56 are mounted in the interior 7 of the grinding device.
Contained in a dust-proof and airtight condition. The roller end is formed by a round roller cap 69 in this embodiment.

The drive alternatives shown in FIGS. 2 and 3 can be used in the vacuum-operated mill 1 of FIG. In this mill II, the swinging lever lO is installed essentially outside the casing 2, so that ffr, the drive 26.58 as shown in FIGS. .52 and the swing lever 1o. In this case, the drive machine rotates, for example, around the joint 34 together with the corresponding rocking lever.

FIG. 4 shows a scavenging crushing device according to the invention, in which assemblies consistent with the prior art are designated by the same reference numerals as in FIG. The scavenging grinding device 60 of FIG. 4 has a grinding pan 61 in the area of the roller mill, which grinding pan has a dome-shaped central protrusion 62 for distributing the ground material fed or circulated along the grinding path. The crushed material is classified by classifier 1
1 and extends from the top to the bottom in the center.
Powered by. Around this flow path, a hollow rotor drive shaft 65 is rotatably provided in the drive mechanism of the rotor 12 1p.

The drive mechanism of the left-hand grinding roller 20 roughly corresponds to the alternative shown in the tJTz diagram, the torque being the drive +1 extending in the hollow shaft.
It is applied to the crushing roller 20 by I24. A motor 26 (attached to the outer casing 2 by a fastening strut 41) drives the grinding roller 20 via a driven shaft 42.
are driven individually.

The driven shaft 42 is connected to the opening 6 in the outer casing 2 of the crushing device.
It stands out through 3. The passage opening for the drive shaft and the mounting support, which are not clearly shown in the figures, are designed to be gas-tight to prevent gases and dust.

In this scavenging type crushing device 60, since the swing levers 25 and 27 are disposed within the casing 2, the drive machine cannot be directly fixed to the II]- face of the swing lever 27. The drive 26 must be externally fixed to the mill casing 2 by means of a mounting support 41. The rotational movement of the rollers is thus compensated by the drive shaft 24 via a free adjustment (which can in particular be provided by a universal joint).

By driving each grinding roller 20 individually,
The material to be crushed is blocked or prevented on the upstream side of the rollers, and as a result, there is no slippage, which causes noise during operation of the roller mill and also causes premature wear.
The other-wear phenomenon disappears. This drive unit may also be designed to reduce maximum power to prevent sudden stresses of the type encountered in the prior art. In this way, it is possible to considerably improve the throughput even if a high degree of fineness is required of the material to be ground.

[Brief explanation of the drawing]

Figure 1 shows the scavenging type pulverization according to the prior art to explain the flow pattern ff. It is a front view of the i-neck. FIG. 2 is a schematic axial sectional view of a first alternative example of a grinding roller drive, together with a swinging lever of the roller unit. FIG. 3 is a partial cross-sectional view of a second alternative embodiment of the grinding roller. FIG. 4 is a front view of the scavenging type crushing device of the present invention, and the first
FIG. 3 is a diagram illustrating the drive alternative of FIG. 2, with the reference numerals and assembly retained; On the 1A surface, 20... Grinding roller, 21... Roller body, 22... Roller shell, 23... Hollow shaft, 24... Drive shaft, 25... Rocking lever, 29...・
・Sublink, 35...Bearing housing, 42...
Driven shaft, 43... Joint shaft, 44... Closing device, 45
. . . Joint member, 52 . . . Lashing, 55 . . . Grinding roller, 56 . ,6
4...Material supply route, 65...Drawing of drive shaft 9 (no change in content) FIG, 1 IυヱPatent attorney seat top - (2 people) FIG, 2 FIG, 4 5m FIG. 3 Procedural amendment (voluntary)

Claims (1)

[Claims] (1) A roller mill having at least one grinding roller in a stationary state, the grinding roller being able to be elastically pressed against a rotating grinding pan, and further comprising: a roller mill having at least one grinding roller in a stationary state; A scavenging type crushing device in which an integrated classifier is arranged and a mixture of crushed material and air is supplied from the center of the roller mill to a crushing pan and crushing rollers, and the crushing pan (3) In addition, the grinding rollers (20, 55) also have separate drive means (26, 58) by means of which the grinding rollers (20, 55) are moved into the grinding pan (3) with or without material to be ground. ) is forcibly rotated in the same direction as the grinding pan (3) at a speed that at least matches the theoretical speed during frictional engagement between the grinding roller (20, 55) or a speed higher than this theoretical speed. A scavenging type crushing device. (2) The scavenging type crushing device according to claim 1, comprising several crushing rollers, each crushing roller (20, 55)
A driving torque of 0 to T_roller is added to the It is determined by __n/number of crushing rollers (kNm),
Here, T_gri_in_de_ing_g__pan_ is the driving torque of the grinding pan, and T_roller is the maximum driving torque of one grinding roller. A scavenging type crushing device characterized by: (3) The scavenging type crushing device according to claim 2, wherein the speed of the crushing rollers (20, 55) changes steplessly. (4) A scavenging grinding device according to claim 3, characterized in that the speed of the grinding rollers (20, 55) is adjustable as a function of the fineness of the ground material. (5) The scavenging type crushing device according to claim 1, having several crushing rollers, each crushing roller (20) being mounted on a fixed hollow shaft (23), in which a Drive shafts (24, 42, 43,
45) is arranged, and the drive shaft is driven by the crushing roller (2
A scavenging type crushing device characterized in that the crushing is carried out on the side far from the (6) The scavenging type crushing apparatus according to claim 5, wherein the drive shaft (24, 42, 43, 45) is adjustable in the radial direction. (7) The scavenging type crushing device according to claim 5, wherein the drive shaft (24, 42, 43, 45) is adjustable in the axial direction. (8) In the scavenging type crushing device according to claim 5, a closing device (44) is provided on the side of the hollow shaft (23) facing the roller mill center (8), and this closing device (44) is provided in the crushing device. A scavenging type crushing device characterized in that the hollow shaft (23) is sealed against the interior (7) of the (6) and torque is transmitted to the crushing roller (20). (9) The scavenging type crushing device according to claim 1, comprising a casing, several crushing rollers, and a rocking lever combined with each crushing roller, each crushing roller (55)
is fixed to a roller shaft (56), this roller shaft is rotatably mounted in the casing (2), and this roller shaft (56) is fixed to a driving means (58). A scavenging type crushing device featuring: (10) The scavenging type crushing device according to claim 1, comprising a casing, several crushing rollers, and a swing lever combined with each crushing roller, and each crushing roller (55
) is fixed to a roller shaft (56), this roller shaft is rotatably mounted on a swinging lever combined with a crushing roller (55), and this roller shaft (56) is connected to a driving means ( 58)
A scavenging type crushing device, characterized in that it is fixed to. (11) The scavenging type crushing device according to claim 5, comprising a casing, and the driving means (26, 58) is provided on the casing (2) so that it cannot be connected to the scavenging type crushing device. . (12), comprising a roller mill with several grinding rollers mounted in a stationary state, such that these grinding rollers can be elastically pressed towards a rotatably driven grinding pan, and above the roller mill; An integrated classifier is installed, the grinding material/air mixture is essentially fed from the center of the grinding roller to the grinding pan and the grinding roller, and a separate drive means for forcing the grinding roller to rotate at a certain speed. It is a scavenging type crushing device equipped with a
20, 25) occurs in the same direction as the grinding pan (3) and is higher than the theoretical speed during the frictional engagement of the grinding pan (3) with the grinding material and the particular grinding roller (20, 25). Each grinding roller (20) is mounted on a fixed hollow shaft (23), in which drive shafts (24, 42, 43, 45) for the grinding roller (20) are mounted.
A scavenging type crushing device characterized in that the drive shaft is driven on the side far from the crushing roller (20). (13), comprising a roller mill with several grinding rollers mounted in a stationary state, such that these grinding rollers can be elastically pressed towards a rotatably driven grinding pan, and above the roller mill; An integrated classifier is installed, and the pulverized material/air mixture is woodenly supplied from the center of the pulverizing roller to the pulverizing pan and the pulverizing roller, and a separate driving means for forcibly driving the pulverizing roller to rotate at a certain speed. It is a scavenging type crushing device equipped with a
20, 25) occurs in the same direction as the grinding pan (3) and is higher than the theoretical speed during the frictional engagement of the grinding pan (3) with the grinding material and the particular grinding roller (20, 25). 0 to T_ to each crushing roller (20, 55).
The driving torque of the roller is added, and this driving torque is expressed as follows: It is determined by the number of rollers (kNm),
Here, T_gri_in_de_ing_g__pan_ is the driving torque of the grinding pan, and T_roller is the maximum driving torque of one grinding roller. A scavenging type crushing device characterized by: