RU2465961C1 - Compound vibratory mill - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to fine grinding of various mineral and organic materials including cement, sand, and ceramic slurry. Compound mill comprises drive shaft with two opposed cams and two grinding chamber assemblies. Chambers in every assembly are interconnected and engaged with drive shaft via, at least, one carrier. The latter is fitted on drive shaft cam via bearing. Every said carrier is shaped to multiarm regular sprocket with central mount opening and supports for grinding chambers of arm ends. Said sprockets are fitted on said shaft with angular shift to allow arranging grinding chambers in clearances between grinding chambers of another assembly.

EFFECT: higher efficiency and stability.

7 cl, 4 dwg

Description

FIELD OF THE INVENTION

The invention relates to techniques for fine grinding and mechanical activation of various materials of mineral and organic origin, including cement, sand, slip.

State of the art

Known multi-chamber vibration mill (see patent for invention SU No. 1748869, IPC B02C 19/16, op.23.07.92). Common features of the mentioned mill with the claimed solution are the following: the presence of parallel tubular chambers placed around the vibrator with grinding bodies, connected at the ends by flexible sleeves with loading and unloading bins and mounted on elastic supports made with the possibility of changing the height, which provides an inclined arrangement of the chambers, facilitating promotion of material to the exit. The device has high performance and allows simultaneous processing of various materials. However, due to the fact that all the cameras are interconnected and with a planetary vibrator located in the center of the bundle in a single unit, the device is subject to unbalanced vibration loads transmitted to the foundation.

Known vibrocentrifugal mill (see patent for utility model No. 18501, IPC B02C 17/08, publ. 06/27/2001). Common features of the mentioned mill with the claimed solution are the following: the presence of a drive shaft with oppositely directed eccentrics and grinding chambers connected to the drive shaft by means of carriers mounted on the eccentric necks of the drive shaft and made with a lodgement for the grinding chamber at one end, with the second end of each drove fixed to the frame. The disadvantages of the known mill include low productivity and the resulting imbalance due to the placement of both grinding chambers on one side relative to the drive shaft, which imposes restrictions on the speed of the drive shaft and leads to the need to lay a more powerful foundation.

Known devices of vibratory ball mills with an eccentric drive, in which to balance the device it is proposed to evenly distribute grinding drum chambers relative to the drive shaft: double-sided, as in patent No. 103835, IPC B02C 19/16, publ. 11.25.55, or tripartite, as in patent SU No. 114028, IPC B02C 19/16, publ. 04/22/57, in both of the above mills, each grinding drum is mounted on the eccentrics of the drive shaft of the corresponding orientation and is not connected with other grinding drums.

The disadvantages of the aforementioned devices include the limited ability to increase productivity.

As the closest analogue, for the claimed technical solution, a multi-chamber vibration mill for grinding various materials was adopted (see patent for invention No. 164784, IPC B02C 19/16, published on 08/19/1964). The mill contains an eccentric drive shaft with diametrically oppositely directed eccentrics and two blocks of grinding chambers, in each of which the grinding chambers are rigidly connected to each other and to the drive shaft by means of a traverse carrier mounted on the eccentric journal of the shaft through the bearing units. The carriers of one block are mounted on eccentrics of the same orientation, and the carriers of the other block are mounted on eccentrics of the opposite direction, which provides antiphase movement of the grinding chambers of the blocks.

The disadvantage of this mill is that each unit individually is a statically unbalanced system relative to the drive shaft, due to the location of the grinding chambers of each of the blocks on one side of the shaft. To balance the system, an additional bilateral fastening to the support of the traverse carrier of each block was made, which leads to a complication of the device and an increase in the support massiveness. As a disadvantage, one can point out the limited possibilities of increasing the productivity of the device.

Disclosure of invention

The task of the invention is to increase the productivity of a vibratory mill while improving its balance and stability.

The problem is solved due to the fact that in a multi-chamber vibration mill containing a drive shaft with diametrically opposite clowns and two blocks of grinding chambers, in each of which chambers are connected to each other and to the drive shaft by means of at least one carrier mounted on the clown drive shaft through a bearing, according to the claimed invention, each carrier is made in the form of a multi-beam correct sprocket with a central bore and with lodges for grinding chambers s rays, with the sprocket mounted on the shaft with an angular displacement, ensuring occupancy grinding chambers of one block in the gaps between the grinding chamber of another unit.

The concept of a "multipath" asterisk implies the presence of three or more rays.

The design of the carrier in the form of a “correct” multi-ray sprocket is characterized by the uniform distribution of its rays around the central landing hole, which follows from the definition of the “correct” star, in which all internal and external angles are equal, and the execution of the rays of the same length. Lodges for grinding chambers are formed at the ends of the beams.

Such a design of the carrier, regardless of the number of sprocket rays, made it possible to ensure the uniformity of the grinding chambers of each of the blocks relative to the drive shaft and to evenly distribute the loads along the drive shaft cross section, as well as to provide a circular path of the grinding media inside the chambers during operation of the device. As a result, each block is a system statically balanced with respect to the drive shaft.

The carrier blocks are mounted on the drive shaft with an angular displacement, i.e. rotated relative to each other at an angle that ensures the placement of grinding chambers of one block in the gaps between the chambers of another block. As a result, the chambers of both blocks, in the aggregate, are also uniformly distributed around the drive shaft.

Due to the fact that the carriers of one block are mounted on eccentrics of the same direction, and the carriers of the other block are mounted on eccentrics of the opposite direction, the blocks move when the device is in antiphase, due to which they mutually cancel each other out.

Thus, one technical result of the proposed solution is to obtain two statically balanced systems relative to the drive shaft, which mutually balance each other during the operation of the device, which can significantly increase the static and dynamic stability of the device and eliminate the possibility of imbalance, thereby eliminating the need to use a powerful foundation.

Another positive result of the proposed solution is the exclusion of rigid kinematic connections of the carrier with the mill frame: the carrier is installed only on the eccentric necks of the drive shaft and is not additionally connected with the frame. This allowed us to simplify the design of the device and at the same time achieve circular motion of grinding chambers and grinding media in them. As a result, grinding media mainly have an abrasive effect on the material, which is energetically most beneficial for ultrafine grinding.

Another positive technical result of the proposed solution, achieved thanks to the original design of the carrier in the form of a multipath star, is to increase the productivity of the device and the availability of the possibility of its further increase. So, replacing three-beam sprockets with, for example, five-beam ones, you can increase the number of grinding chambers from 6 to 10, without disturbing the balance and balance of the device as a whole.

The presence of a large number of grinding chambers allows simultaneous processing of several different materials.

In the preferred embodiment of the device, each carrier is made in the form of a three-beam sprocket with rays of equal length diverging from the center at an angle of 120 °.

It is advisable to install the grinding chambers of each block by means of a pair of carriers, for which two pairs of diametrically opposite eccentrics are placed on the drive shaft, spaced apart alternating along the length of the shaft.

The inclined arrangement of the grinding chambers is preferable, which contributes to a faster passage of the processed material to the exit, as a result of which the productivity of the device is increased, and the best conditions for processing materials are created. The most optimal angle of inclination of the mill is an angle of 20-40 ° to the horizon.

It is preferable to fill the grinding chamber with grinding media in 80-90% of the volume. Mentioned filling less than 80% reduces the quality of grinding, and its increase of more than 90% reduces the mobility of the load and reduces productivity.

In the specific case of the device, the loading and unloading nozzles of the grinding chambers are made in the form of flexible hoses connected to the end walls of the chambers, passed through the openings of the casing covering the device.

Brief Description of the Drawings

The invention is illustrated by the accompanying drawings, where:

figure 1 - General view of the device, the kinematic diagram;

figure 2 is an example of a specific implementation of the device corresponding to section AA from figure 1, the carrier is made in the form of three-beam stars;

figure 3 shows the node connection carrier with the shaft;

figure 4 is a diagram illustrating the operation of the device for three-beam (a), four-beam (b) and five-beam (c) sprockets.

The implementation of the invention

The vibration mill (see Fig. 1) contains a frame 1, in the bearing bearings 2 of which a drive shaft 3 is mounted, carrying two pairs of eccentrics 4 and 5, which are opposite on the shaft, i.e. directed diametrically opposite. On the eccentrics 4, 5 are installed by means of the bearing units of the carrier 6 and 7, the bearing blocks of the grinding tube chambers 8 and 9, respectively.

Frame 1 is mounted with the ability to change the angle of inclination. To the ends of the grinding chambers 8 and 9 are suitable flexible loading 10 and unloading 11 pipes, passed through holes in the end walls of the protective casing 12.

Drove 6 and 7 are made in the form of three-beam stars with a central landing hole 13 and rays 14 of the same length diverging from the center at an angle of 120 ° to each other (see Figs. 2, 3). Figure 3 shows the node connection carrier with the drive shaft. A bearing 15 is pressed into the central hole 13 of the carrier (6, 7), mounted on an eccentric sleeve 4 or 5, respectively, mounted on the shaft 3.

At the ends of the beams 14, tool holders 16 are formed to accommodate grinding chambers. The fixing of the grinding chambers in the lodgements is carried out with clamps 17.

Sprockets 6 are mounted on the shaft 3 with an angular displacement relative to the sprockets 7 by an angle α, which ensures a uniform arrangement of the chambers 9 in the spaces between the chambers 8.

The device operates as follows.

The material enters the chambers 8 and 9 through the loading nozzles 10 and moves between the grinding balls to the discharge end due to the difference in pressure of the material at the inlet and outlet and due to the inclined position of the chambers. The optimum angle of inclination is 20–40 °, which allows reducing the time of the impact of grinding media on the material being ground, due to which it is possible to obtain larger material and increase productivity by almost 2 times, compared to horizontal installation.

The eccentric shaft 3 of the mill, which, together with the drive, acts as a vibration exciter, causes the carrier 6 and 7, together with the grinding chambers 8 and 9, mounted on them, to oscillate along a circular path with a given amplitude equal to two eccentricities. A centrifugal force arises inside the chambers, which leads to an intense and abrasive effect of grinding media on the material being processed. The optimal filling of grinding chambers with grinding media is 80-90% of the volume.

The centers of mass (G ₁ and G ₂ ) of each of the blocks are located (see Fig. 4) in the center of the carrier and symmetrically on the sides of the axis O of the shaft 3 at an eccentric distance e .

The symmetry of the displacement of the centers of mass and its insignificant value e allow us to consider the blocks statically balanced relative to the shaft and to each other.

In the process of operation of the device, the blocks move out of phase and at each moment of time one camera unit balances the other.

As can be seen in FIGS. 4a and 4c, in cases of 3- and 5-beam sprockets being executed, at each instant of time, each of the chambers 8 is located relative to the shaft axis O diametrically opposite to one of the chambers 9, and the force vectors F ₈ and F ₉ acting at these cameras are directed oppositely and balance each other out.

As a result, balancing of the blocks occurs and imbalance is eliminated.

On figb shows an example of the execution of stars with 4 rays. In this case, at each moment of time, each of the chambers 8 is balanced by a pair of chambers 9 'and 9''located symmetrically with respect to the diametrically opposite reflection of this chamber 8. The figure shows that the force F ₉ obtained by the addition of forces F ₉ ' and F ₉ '' applied to the chambers 9 'and 9'', respectively, is also equal and directed opposite to the force F ₈ , which ensures their balancing.

In fact, one block of grinding chambers acts as a counterweight to another block. Moreover, since Since the blocks are made in the same way and are equally subject to wear, the balance achieved is ensured throughout the entire life of the device.

Thus, the design of the proposed mill is characterized by low sensitivity to imbalance, which allows you to put the mill with a slope towards the discharge side, use higher speeds of rotation of the eccentric shaft and at the same time reduce the metal consumption of the support frame and do without a powerful foundation.

The loading 10 and unloading 11 pipes perform the functions of flexible couplings, providing the supply and unloading of material and at the same time not interfering with the movements of the drums 8 and 9.

The implementation of the end walls of the casing 12 with holes 18 through which the flexible pipes 10 and 11 are passed, eliminates the possibility of twisting the grinding chambers together with the shaft 3 and increase the reliability of the device.

Claims (7)

1. A multi-chamber vibration mill comprising a drive shaft with diametrically opposite eccentrics and two grinding chamber blocks, in each of which the chambers are connected to each other and to the drive shaft by means of at least one carrier mounted on the drive shaft eccentric through a bearing, characterized in that each carrier is made in the form of a multi-beam correct sprocket with a central landing hole and with lodgements for grinding chambers at the ends of the beams, while the sprockets are mounted on a shaft with angular escheniem providing accommodation grinding chambers of one block in the gaps between the grinding chamber of another unit. 2. The mill according to claim 1, characterized in that each carrier is made in the form of a three-beam sprocket with rays of equal length located at an angle of 120 ° relative to each other. 3. The mill according to claim 1, characterized in that two pairs of diametrically opposite eccentrics are placed on the shaft, spaced along the length of the shaft with alternating between each other, each block of grinding chambers is fixed by means of two carriers mounted on the eccentrics of the corresponding pair. 4. The mill according to claim 1, characterized in that the drive shaft is mounted by means of bearing assemblies in a frame mounted with the possibility of changing the angle of inclination. 5. The mill according to claim 1, characterized in that each grinding chamber is filled with grinding media for 80-90% of the volume. 6. The mill according to claim 1, characterized in that the loading and unloading nozzles of the grinding chambers are made in the form of flexible hoses connected to the end walls of the chambers. 7. The mill according to claim 6, characterized in that it is equipped with a casing freely covering the grinding chambers and made with holes for the loading and unloading hoses of the grinding chambers.

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