JPH03217250A - Vertical type grinder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a vertical pulverizer that pulverizes cement raw materials, coal, chemicals, etc. through the cooperation of a rotating table and pulverizing rollers. [Prior Art] Vertical crushers equipped with a rotary table and a jitter are widely used as a type of crusher for finely crushing powders such as cement raw materials, coal, and chemicals. This type of crusher consists of a disk-shaped rotary table that is driven by a motor with a reducer and rotates at low speed in the lower part of a cylindrical casing, and a part that divides the outer circumference of the upper surface equally in the circumferential direction, which is pressed by hydraulic pressure or the like. It is equipped with multiple rollers that rotate as a result of rotation. In this vertical crusher, powder as a raw material is supplied to the center of the rotary table through a supply pipe, and when the table rotates, the powder is subjected to centrifugal force in the radial direction of the table, and as it slides on the table, it is rotated by the table in the direction of rotation. It receives the force, slides between it and the table, and rotates somewhat slower than the table rotation speed. The above two forces, ie, the radial and rotational forces, are combined, and the powder moves to the outer periphery of the rotary table, drawing a spiral trajectory on the table. Since the roller is in pressure contact with this outer periphery and is rotating, the grains with spiral lines enter between the roller and the rotating table from a direction forming a certain angle with the roller axis direction, and are bitten and pulverized. do. On the other hand, hot air is guided to the base of the casing by a duct, and this hot air flows into an air flow passage (herein referred to as an annular space) between the outer peripheral surface of the rotary table and the inner peripheral surface of the casing. ), the fine powder rises inside the casing without being dried, and is discharged from the outlet as a mixture with hot air and sent to the next process.

By the way, it is impossible for the material to be crushed supplied to the crusher to be crushed to the fine powder particle size required by this crusher if it is subjected to the crushing action by the crushing rollers only once. Not all of the crushed material is bitten by the crushing rollers, so even if the powder and granules that reach the outer peripheral edge of the rotary table rise up on the hot air current blown up from the annular space, they will not be able to be crushed by the crusher. By the time the particles reach the separator installed at the top, depending on their particle size, they may fall or be classified and removed by the separator and returned to the rotary table.

In this way, the material to be crushed, which is constantly fed into the crusher, rises from the rotary table to the separator, or rises from the rotary table to the separator until it reaches the desired fine powder particle size that will become the final product and flows out of the crusher. The falling particles are repeated many times on their way to the separator and are gradually pulverized to the desired particle size.

[Problems to be Solved by the Invention] In the conventional vertical crusher as described above, a considerable amount of the material to be crushed that reaches the biting side of the rollers on the table is not bitten by the rollers. It is normal for it to be swept away into the annular space. Among the materials to be crushed that are pushed into the annular space on the biting side of the rollers, those with large particle sizes become waste stones and fall through the annular space, increasing the amount of waste stones and increasing the amount of processing work. let In addition, the small particles of the crushed material that have been swept into the annular space are scattered again, which increases the load applied to the separator and tends to cause a decrease in classification efficiency. Furthermore, by forcing a large amount of material to be crushed into the annular space, the ventilation pressure loss of the annular space increases, thereby increasing the fan power.

In this way, in order to blow up and circulate the overflow granules, a crusher requires air blowing equipment with an air volume several times the required air volume, and the increased circulation volume requires a large air volume and pressure, which increases equipment costs. Not only does this significantly increase power consumption, but also, especially when ultrafinely pulverizing raw materials with relatively poor physical properties, mill vibrations often occur, and the vibration value (amplitude) is particularly high. In severe cases, equipment may be damaged or become inoperable, forcing the company to suspend operations.

Therefore, as a countermeasure when large vibrations occur, the table weir height, crushing pressure, and table rotation speed are controlled in order to change the gravitational frequency of the raw material layer in the crushing section and move it away from the resonance area. However, making the rotary table's drive device variable would require excessive equipment costs and is unlikely to be practical.To change the table weir height (dam ring height) It is necessary to stop the operation of the mill for internal work, and there is also the problem that changing the crushing pressure can cause the product particle size to change from the desired one, so in reality, the solution is to reduce the mill throughput. This was causing a loss of stable production planning. Therefore, even if mill vibration occurs, the vibration frequency of the pulverized raw material layer is changed to reduce the vibration amplitude, without significantly reducing the mill throughput, and the normal stable operating state with low vibration can be quickly restored. Some kind of means was needed. These vibrations tended to occur more frequently in finely pulverized or ultra-fine pulverized particles than in medium pulverized areas.

[Means for Solving the Problems] In order to achieve the above object, the vertical crusher of the present invention has the following features: A plurality of rotatable crushing rollers are arranged on the upper surface of the outer periphery of the rotary table, and the rollers are supplied to the center of the rotary table. In a vertical crusher, the raw material is crushed between the top surface of the rotary table and the circumferential surface of the crushing roller by applying a predetermined crushing pressure to the crushing roller.
A rotatable auxiliary roller is disposed on the upper surface of the outer periphery of the rotary table between the pulverizing rollers, and the auxiliary roller compresses the layer of raw material that is bitten into the pulverizing roller with its circumferential surface, and the auxiliary roller and the pulverizing roller The configuration is such that a tilted plate with its tilt direction facing toward the center of the rotary table is fixedly installed in between. [Operation] The raw material supplied from the raw material input chute to the upper surface of the center of the rotary table traces a spiral trajectory on the rotary table, moves toward the outer circumference of the rotary table, reaches the biting side of the auxiliary roller, and connects the auxiliary roller and the rotary table. When the particles flow between the auxiliary roller and the roller, the auxiliary roller rotates and compresses the raw material particles with the required pressing force on its circumferential surface, and each compressed raw material particle is made into a sparrow-like state and becomes a so-called piezoelectric layer. Ru. This compressed layer reaches the biting side of the crushing roller by the rotation of the rotary table, and even if the crushing roller is applied with a high pressing force as crushing force, it will be bitten with a higher probability and continuous crushing will be performed. In addition, the raw material particles, which are crushed by the crushing roller and flowed as a coarse layer, are discharged from the anti-biting side of the crushing roller, and are subjected to a similar compaction effect by this auxiliary roller, and then crushed to the next position. There is a high probability that it will get caught in the rollers and be crushed efficiently. The pressing force of the auxiliary roller toward the top of the rotary table does not contribute to pulverization, but instead compresses the raw material particles to form a layer with dense particles, the so-called consolidation layer (hereinafter, the action of forming such a layer is called consolidation). ), which is much smaller than the pressing force of the crushing roller.

If the above-mentioned auxiliary roller is arranged close to the raw material biting side of the crushing roller, the new raw material from the raw material input chute guided to the outer periphery of the rotary table will be difficult to flow into the raw material biting side of the crushing roller, and the auxiliary roller will Since the proportion of raw material flowing into the raw material biting side increases, the compacted layer in which the raw material particles are compacted by the auxiliary roller is less likely to be disturbed by the new raw material, and the biting into the crushing roller is performed more reliably. It will be done. Of course, the raw material crushed by the previous crushing roller and the new raw material are consolidated together by this auxiliary roller. At the same time,
By forming a consolidated layer with a constant thickness using an auxiliary roller, the natural frequency of the raw material layer is kept constant, and vibrations are prevented.
<This is the second main function of the auxiliary roller.

In this way, the powder layer compacted by the auxiliary roller is efficiently pulverized by the pulverizing roller disposed after the auxiliary roller, and the raw material layer is kept at a constant height to prevent vibrations. However, despite this, for some reason the layer thickness has increased, which has caused the mill vibration to suddenly become more intense.

In this case, the properties and moisture content of the pulverized raw material change and the pulverizability of the raw material deteriorates, and as a result, the thickness of the raw material layer on the rotary table becomes larger than normal, and the vertical pulverizer of the present invention In this method, a scraper is installed on the biting side of the auxiliary roller, and this scraper causes the increased thickness of the raw material layer to overflow to the outside of the rotary table, in order to maintain the thickness of the raw material layer that always flows into the auxiliary roller at a constant level. It is something. Therefore, even if the properties of the raw material change, only a constant layer thickness is supplied to the auxiliary roller, which is consolidated and the regular grinding action is continued by the grinding roller, which may cause problems such as a decrease in grinding capacity or a change in the particle size distribution of the product. The negative effects of

In addition, the rotary table is overflowing onto the consolidated layer formed by the auxiliary rollers, and particles blown up by the airflow in the annular space are tilted to prevent them from falling and disturbing the consolidated layer of a constant thickness. A plate is provided, and the particles falling onto the inclined plate gather at the center of the rotary table and head toward the auxiliary roller again. [Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

1 to 5 show embodiments of the present invention, FIG. 1 is a schematic longitudinal sectional view of the whole, FIG. 2 is an enlarged view of the main part of the crushing part, FIG. 2(a) is a longitudinal sectional view, Figure 2(b) is a plan view, Figure 2(C)
) is a side view, Fig. 3 shows the arrangement of the scraper, auxiliary roller, and crushing roller, Fig. 3(a) is a plan layout,
Fig. 3(b) is a front development view of Fig. 3(a), Fig. 4 shows the mounting situation of the inclined plate, Fig. 4(a) is a plan view, and Fig. 4(b) is a vertical cross-sectional view. , Fig. 5 is an explanatory diagram showing the state of powder downstream of the auxiliary roller, Fig. 5(a) is a side view without the inclined plate, and Fig. 5(b) is a front view with the inclined plate attached. This is a developed diagram. In FIG. 1, the pulverizer Ial is equipped with a casing 20 that houses the entire pulverizer such as a rotary table 3, which will be described later. , a middle casing 20b in which an inner cone 20c with a circular cross section is internally drawn, and an upper casing 20d joined to the upper end of the middle casing 20b.
It is equipped with

A reducer 2 with a motor is disposed in the center of the lower casing 20a, and a rotary table 3 formed in a disc shape is attached to the output shaft facing upward. It is driven and rotates clockwise when viewed from above in Figure 1. Reference numeral 5 denotes a plurality of roller post arms, and a plurality of roller post arms are arranged at the upper outer peripheral end of the rotary table 3, and each of the roller post arms 4 has a truncated conical crushing roller 4 pivotally attached to the lower end thereof, and is pivoted in a substantially horizontal state. There is. A pressure frame 6 having an annular shape (an annular shape in this embodiment) is fixed to the upper surface of the upper inner peripheral end of the roller post arm 5 by means such as bolt tightening, and a plurality of crushing rollers 4 and rollers are attached to the pressure frame 6. The boss arm 5 and the pressure frame 6 are integrally formed and mounted on the upper surface of the rotary table 3. On the other hand, the upper outer peripheral end of each roller post 5 is rotatably connected to a connecting rod 8 and a turnbuckle 9 by a pin 7 and a fork end 7a.
and the hydraulic cylinder 1 via the cylinder rod 10a.
0, and the lower end of the hydraulic cylinder lO is connected to the rotating bin ll.
and is connected to the base plate 13 by a rotating seat l2. Each crushing roller 4 is connected to a roller post 5 via a roller shaft 4a.
The rotary table 3 is rotatably supported by a shaft, and its circumferential surface is in contact with the outer peripheral surface of the upper end of the rotary table 3, so that it can be rotated in accordance with the rotation of the rotary table.

Further, on the upper surface of the outer peripheral part of the rotary table 3 where the crushing roller 4 and the adjacent crushing roller 4 are located, each crushing roller 4 is provided.
An auxiliary roller 30 having a smaller diameter than the crushing roller 4 is arranged at a position close to the raw material biting side. As shown in FIG. 2(C), this auxiliary roller 30 is rotatably mounted on a roller shaft 35 fixed to the tip of a substantially U-shaped arm 31 that is rotatably supported on the casing 20 by a shaft 33. It is mounted on a translocated shaft. arm 3l
A piston rod 32a of a hydraulic cylinder 32 is supported and connected to the lower end of the piston rod 32a, and a constant pressure of oil pressure is applied to a rod end chamber 32b of the hydraulic cylinder 32 to apply compression force to the layer of raw material. The end of the hydraulic cylinder 32 on the side opposite to the piston rod is rotatably supported by the casing 20.

Note that this compression force is achieved by adjusting the hydraulic pressure with a pressure regulating valve (not shown) attached to a hydraulic line connected to the rod end chamber 32b of the hydraulic cylinder 32. Further, an accumulator is connected to this hydraulic line, and the rod end chamber 32b of the hydraulic cylinder 32 is maintained at a constant pressure. By expanding and contracting the piston rod 32a of the hydraulic cylinder 32, the arm 31 is rotated about the shaft 33, and the auxiliary roller 30 moves up and down. A gap adjuster 34 for adjusting and setting the gap between the auxiliary roller 30 and the top surface of the rotary table 3 is provided at the lower part of the arm 3l, and the gap adjuster 34 is fixed to the casing 20 and has a screw hole protruding therein. The base 34b and this base 3
It consists of a screw shaft 34a that is screwed into the screw hole of 4b and supported, and by bringing the tip of the screw shaft 34a into contact with the side end of the arm 31, the auxiliary roller 30 and the rotary table 3
It is configured so that the gap with the top surface can be set.

Note that if the weight of the auxiliary roller 30 is sufficient as the compression force for the layer of raw material, the hydraulic cylinder 30 is left free. On the other hand, above the center of the rotary table 3 is a discharge port 22a.
is opened, and the final fine powder discharge pipe 22 is connected. Further, from above the casing, a raw material supply pipe 16 penetrates the ceiling wall of the discharge pipe 22 and is inserted into the discharge port 22a, and is arranged so that its lower end reaches near the lower part of the separator 15. This raw material supply pipe l6 is supported by the upper casing 20d via a discharge pipe 22, and around this raw material supply pipe l6, a separator l5 formed of an inverted conical cylinder is connected to the middle casing 20b by a stay (not shown). is supported by A plurality of movable vanes 15a are arranged evenly in the circumferential direction on the outer circumferential upper surface of the upper end of the separator 15 for applying a swirling force to the incoming dust gas, and a shaft 15 whose one end is supported by a bearing 15c
It is rotatably adjustable from the outside using b and handle 15d.

On the other hand, below the outer periphery of the rotary table 3, an annular hot air passage 2l is provided which is connected to the hot air generator by a duct 18, and above the hot air passage 21, the rotary table 3 and the casing 20a are connected. An annular space l4 is defined between the inner peripheral wall 14a and the outer peripheral wall 14b. In this annular space 14, a plurality of plate-shaped blades 14c are arranged and fixed at equal intervals around the circumference while maintaining a required inclination angle with respect to the horizontal plane.

In addition, at the bottom of the hot air passage, there is a discharge shoe for temporarily discharging foreign matter during crushing and excess crushed materials in the event of overload.
9 is installed, and can be taken out from a discharge door 19b which is rotatable around a rotary bin 19a.

On the other hand, on the biting side of each auxiliary roller 30, the height of the raw material layer toward the auxiliary roller 30 from the bottom surface of the rotary table to the surface of the raw material layer, that is, the layer thickness of the raw material layer (H in Fig. 2 (a)) is measured. The scraper 100 to be restricted is moved in the radial direction or in a direction slightly inclined from the radial direction (Fig. 2(b), Fig. 3(a),
(see Figure (b)). scraper 100
is rotatable about the pin fulcrum 110 of the bin support l20 via the connecting rod 100a, and the other end is connected to the tip of the piston rod 130a of the hydraulic cylinder 130 supported on the pedestal 140 by the bin ioob. The piston rod 130a can move up and down in accordance with the up and down movement of the piston rod 130a.

A flexible air seal 150 is provided at the point where the connecting rod 100a passes through the casing to maintain airtightness inside and outside the mill. Also, Fig. 4(a). (
As shown in b), between the auxiliary roller 30 and the crushing roller 4, an inclined plate 200 whose inclination direction is directed toward the center is fixed to the inner surface of the casing 20 via a support 200a.

The operation of the embodiment of the vertical crusher of the present invention constructed as described above will now be described.

The raw material supplied from the raw material input chute 16 to the upper surface of the center of the rotary table 3 is subjected to the centrifugal force of the rotary table 3, draws a spiral trajectory on the rotary table, and is set at a certain height in advance. It passes through the gap between the scraper 100 and the rotary table 3 (raw material layer thickness H in FIG. 2(a)), is bitten by the auxiliary roller 30, is compacted, becomes a compacted layer, and is further sent to the crushing roller 4 disposed at a later stage. and crushed by a crushing roller 4. The pulverized powder then overflows the rotary table 3, is blown up by the hot air rising at high speed from the annular space 14, and is carried to the separator 15, and due to the classification action of the separator 15, fine powder below the classification point is removed from the discharge pipe 22. On the other hand, coarse powder above the classification point is returned onto the rotary table 3 (these are referred to as returned powder). At this time, the particles blown up by the annular space 14 fall onto the consolidated layer that has been rolled down by the auxiliary roller 30 and formed to a constant thickness, and the thickness of the consolidated layer 60 becomes uneven as shown in FIG. 5(a). There is an inclined plate 200 to prevent
Drop it to the center of the rotary table (Fig. 5(b)).

By repeating the above operations, the pulverizer can continuously pulverize the raw material and continuously obtain fine powder as a product.

However, due to changes in the raw material properties or moisture content during operation, the pulverizability of the raw material may change, and the current pulverization conditions (mill model number, rotational speed of the rotary table, rotary table of the crushing rollers) may change. Even if the tension on the surface, the height of the dam ring, the classification point of the separator, etc. are the same, the proper balance among these is lost, the layer thickness increases, and the mill vibration value becomes abnormally high. be hit by. In this case, as shown in Figures 3(a) and 3(b), the inflowing raw material with a thickness of more than the appropriate raw material layer thickness H is
As shown in (overflow flow), it is removed by the scraper 100, changes direction to the outer peripheral side of the rotary table 3, overflows, and is sent upward by the hot air as described above. On the other hand, the raw material up to the raw material layer thickness H is supplied to the auxiliary roller 30 following the same trajectory as in the conventional method, as shown by F (biting flow) in the figure. In addition, 4A indicates the biting side of the crushing roller, 4B indicates the downstream side of the crushing roller, numeral 50 indicates the coarse layer, and numeral 60
indicates a consolidated layer.

Therefore, even if the thickness of the raw material layer temporarily increases, the thickness of the raw material layer bitten by the crushing roller 4 will not change, and therefore the natural frequency of the raw material layer will not change, so the vibration will suddenly increase. There is no increase, and stable operation can be continued.

With the above-described structure and operation, and by providing a scraper, the present invention can eliminate an increase in the thickness of the raw material layer that is bitten by the grinding rollers, which causes an increase in mill vibration, and therefore can prevent a sudden increase in mill vibration.

[Effects of the Invention] As is clear from the above description, in the vertical crusher of the present invention, since the auxiliary rollers and the inclined plate are provided, the thickness of the raw material layer supplied to the auxiliary rollers and the crushing rollers can be kept almost constant. Because it can be held, it is possible to suppress the sudden increase in mill vibration and continue stable continuous operation, which improves productivity and prevents equipment damage accidents, achieving a longer lifespan of the equipment. It also has excellent maintenance properties.

[Brief explanation of drawings]

1 to 5 show embodiments of the present invention, FIG. 1 is a schematic longitudinal sectional view of the whole, FIG. 2 is an enlarged view of the main part of the crushing part, FIG. 2(a) is a longitudinal sectional view, Figure 2(b) is a plan view, Figure 2(C)
) is a side view, Fig. 3 shows the arrangement of the scraper, auxiliary roller, and crushing roller, Fig. 3(a) is a plan layout,
Figure 3(b) is a front development view of Figure 3(a), and Figure 4(a) is a front development view of Figure 3(a).
) is a plan view, FIG. 4(b) is a vertical sectional view, FIG. 5 is an explanatory diagram of the state of powder near the auxiliary roller. Figure (b) is a side view showing the case where the inclined plate is attached. 1... Vertical crusher, 3... Rotating table, 4... Grinding roller, l4... Annular space, 20... Casing, 30... Auxiliary roller, 32... Hydraulic cylinder, 34... Gap adjuster, 50... Dense layer, 60... Ojaku layer, 100...Scraper, 100a...Connecting rod, 100b...
Pin, 110... Group/Bin fulcrum, 120...
... Pin support, 130 ... Hydraulic cylinder, 130a ... Piston rod, 140 ... Frame, 150 ... Air seal, 200 ... Inclined plate, 200a ...・・・
Support, H: Raw material layer thickness, F: Intrusion flow, G: Overflow flow.

Claims (1)

[Claims] (1) A plurality of rotatable crushing rollers are arranged on the upper surface of the outer periphery of the rotary table, and a predetermined crushing pressure is applied to the raw material supplied to the center of the rotary table to the crushing rollers, and the raw material is crushed between the upper surface of the rotary table and the circumferential surface of the crushing rollers. In the vertical crusher, a rotatable auxiliary roller is provided on the upper surface of the outer periphery of the rotary table between the crushing roller and the crushing roller, and the auxiliary roller is rotatable to compress the layer of raw material bitten into the crushing roller with its circumferential surface. and a vertical pulverizer having a sloping plate fixedly arranged between the auxiliary roller and the pulverizing roller, the slanting direction of which faces toward the center of the rotary table.