JPH03213158A - Vertical grinder - Google Patents

Abstract

PURPOSE:To stably and continuously operate a vertical grinder by mounting a scraper arranged so as to be capable of advancing and retracting up and down and a means allowing the scraper to advance and retract up and down on the raw material-biting side of an auxiliary roller and providing a spray nozzle to the scraper so as to direct the same toward the rear of raw material flow. CONSTITUTION:A plurality of freely rotatable grinding rollers 4 are arranged to the upper surface of the outer peripheral part of a turntable 3 and predetermined grinding pressure is applied to the rollers 4 to grind the raw material supplied to the central part of the turntable 3 between the upper surface of the turntable 3 and the peripheral surfaces of the rollers 4. A freely rotatable auxiliary roller 30 compressing the layer of the raw material forcibly transferred to the rollers 4 by its peripheral surface is arranged to the upper surface of the turntable 3 between the rollers 4. A scraper 100 arranged so as to be capable of advancing and retracting up and down and a means allowing the scraper 100 to advance and retract up and down composed of a hydraulic cylinder 130 are mounted on the raw material-biting side of the roller 30. A plurality of spray nozzles 200 are arranged to the scraper 100 so as to be directed to the rear of raw material flow and piping 220 guiding a fluid to the nozzles 200 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a vertical pulverizer that pulverizes cement raw materials, coal, chemicals, etc. through cooperation between a rotating table and pulverizing rollers.

BACKGROUND ART Vertical crushers equipped with a rotary table and rollers 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 to rotate at low speed in the lower part of a cylindrical casing, and a part that divides the outer circumference of the upper surface into equal parts in the circumferential direction, which is pressed by hydraulic pressure or the like. It is equipped with a plurality of rollers that are driven to rotate.

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, that is, the forces in the radial direction and the force in the rotational direction are combined, and the powder moves to the outer periphery of the rotary table while drawing a spiral trajectory on the table. A roller is pressed into contact with this outer periphery and rotates, so the grains with spiral lines enter between the roller and the rotary table from a direction that forms an angle with the roller axis, and are crushed. 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 is dried and rises inside the casing, 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 into the fine powder particle size required by this crusher if it is subjected to the crushing action by the crushing rollers only once, and the material to be crushed cannot fall into the center of the rotary table. 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 passes through the rotary table until it reaches the desired fine powder particle size to become the final product and flows out of the crusher. - Gradually falls to the separator over and over again until it reaches 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 Furthermore, among the objects to be crushed that have been swept into the annular space, those with small particle sizes 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 manipulated to change the vibration frequency of the raw material layer in the crushing section and move it away from the resonance area. However, making the drive device of the rotary table variable would require excessive equipment costs and is unlikely to be practical, and changing the table weir height (dam ring height) would require It is necessary to stop the operation and carry out 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 the reality is that the mill throughput has to be reduced in the end. , which was to undermine a stable production plan.

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 fine pulverization or ultra-fine pulverization than in medium pulverization regions.

[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 that applies a predetermined crushing pressure to a crushing roller and crushes the raw material between the top surface of a rotary table and the circumferential surface of the crushing roller, the crushed raw material is crushed on the top surface of the outer periphery of the rotary table between the crushing roller and the crushing roller. A rotatable auxiliary roller is provided that compresses the layer of raw material to be bitten into the roller on its circumferential surface, and a scraper is disposed on the raw material biting side of the auxiliary roller so as to be movable up and down, and the scraper can be moved up and down. A plurality of spray nozzles are arranged on the scraper toward the rear side of the raw material flow, and piping is arranged to guide fluid to the spray nozzles.

[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 raw material particles flow between the auxiliary roller and the raw material particles, 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 brought into a dense state, forming a so-called compacted layer. Ru. This compacted 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. Also, it is crushed by a crushing roller into small pieces, and then released from the non-biting side of the crushing roller. The raw material particles flowing as a coarse and dense layer are subjected to a similar compaction effect by this auxiliary roller, and are bitten into the next crushing roller with a high probability and are efficiently crushed. 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.

When 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 that is guided to the outer periphery of the rotating table flows into the raw material biting side of the crushing roller and becomes auxiliary. Since the proportion of raw material flowing into the raw material biting side of the roller increases, the compacted layer in which the raw material particles are compressed by the auxiliary roller and made dense is less likely to be disturbed by the new raw material, and the biting into the crushing roller becomes more reliable. It is 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, the second main function of the auxiliary roller is to maintain the natural frequency of the raw material layer constant by forming a consolidated layer of constant thickness using the auxiliary roller, thereby making it difficult for vibrations to occur.

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 the material layer thickness increased by this scraper overflows to the outside of the rotary table, so that the thickness of the material layer flowing into the auxiliary roller is always kept constant. It is something to do. Therefore, even if the properties of the raw material change, only a constant layer thickness is supplied to the auxiliary roller, and the spray nozzle adds moisture to the raw material to make it easier to bite into the raw material, which is compacted and the crushing roller performs the regular crushing action. Since this continues, adverse effects such as a reduction in grinding capacity and a change in the particle size distribution of the product are prevented.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

1 to 3 show an embodiment of the present invention, FIG. 1 is a schematic vertical cross-sectional view of the whole, FIG. 2 is an enlarged view of the main part of the crushing part, and FIG. 2(a) is a vertical cross-sectional view. Figure 2(b) is a plan view, Figure 2(C)
) is a side view, Figure 3 shows the arrangement of the scraper, auxiliary roller, and crushing roller, and Figure 3 (a) is a plan layout, and Figure 3 (b) is a front view of Figure 3 (a). This is a developed diagram.

In FIG. 1, the crusher l is a rotary table 3 which will be described later.
The casing 20 includes a cylindrical lower casing 20a fixed to the floor, and an inner cone 20c with a circular cross section drawn in the middle. Middle part casing 2
0b, and an upper casing 20d joined to the upper end thereof.

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 FIG. 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 5 has a conical head-mounted crushing roller 4 pivotally attached to the lower end thereof, and is pivoted in a substantially horizontal state. ing.

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 post arm 5 and the pressure frame 6 are integrally formed and mounted on the upper surface of the one-turn table 3. On the other hand, the upper outer peripheral end of each roller post 5 is rotatably connected to a connecting rod 8 by a pin 7 and a fork end 7a. turnbuckle 9
and the hydraulic cylinder 1 via the cylinder rod 10a.
0, and the lower end of the hydraulic cylinder 10 is connected to the rotary bin 11
and is connected to a base plate 13 by a rotating seat 12.

Each crushing roller 4 is connected to a roller post 5 via a roller shaft 4a.
The rotary table 3 is rotatably supported on a shaft, and its circumferential surface is in contact with the outer circumferential 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 rollers 4 are located, an auxiliary roller 30 having a smaller diameter than the crushing roller 4 is installed at a position close to the raw material biting side of each crushing roller 4. It is located.

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 31
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 is provided at the bottom of the arm 31 to adjust and set the gap between the auxiliary roller 30 and the top surface of the rotary table 3. The gap adjuster 34 is fixed to the casing 20 and has a screw hole projecting therein. The base 34b and this base 3
The screw shaft 34a 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 compressive force for the layer of raw material, the hydraulic cylinder 30 is left free.

On the other hand, above the center of the one-turn table 3 is a discharge port 22a.
is opened, and the final fine powder discharge pipe 22 is connected. Further, the raw material supply pipe 16 is inserted from above the casing through the ceiling wall of the discharge pipe 22 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 16 is supported by the upper casing 20d via a discharge pipe 22, and around this raw material supply pipe 16, a separator 15 formed of an inverted conical cylinder is connected to the middle casing 20b by a stay (not shown). is supported by On the upper surface of the outer periphery of the upper end of this separator 15.

A plurality of movable vanes 15a for imparting swirling force to the incoming dust gas are arranged evenly in the circumferential direction, and can be freely rotated and adjusted from the outside by a shaft 15b whose one end is supported by a bearing 15c and a handle 15d. It has become.

On the other hand, an annular hot air passage 21 is provided below the outer periphery of the one-turn table 3 and is connected to a hot air generator by a duct 18. An annular space 14 is defined between the inner circumferential wall 14a and the outer circumferential 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 (1) that temporarily discharges foreign objects 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 rotation pin 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 regulating scraper 100 is radially or 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 pin support 120 via the connecting rod 100a, and the other end is connected to the tip of the piston rod 130a of the hydraulic cylinder 130 pin-supported on the pedestal 140 by a pin toob. 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 part where the connecting rod 100a passes through the casing to maintain airtightness inside and outside the mill.

Further, on the side of the scraper 100 in the downstream direction of the flow of the pulverized raw material, four spray nozzles 200 are arranged almost horizontally with the nozzle directions facing downward. A header 210 and piping 220 for supplying water (water or diethylene glycol aqueous solution) are provided and connected to water supply equipment outside the mill.

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 rises from the annular space 14 at a high speed. blown up by hot air,
The powder is carried to the separator 15, and due to the classification action of the separator 15, the fine powder below the classification point is discharged through the discharge pipe 22, while the coarse powder above the classification point is returned onto the rotary table 3.

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 changes, and the current pulverization conditions (mill model number 9 concave rotary table rotation speed, grinding roller rotation speed) Tension force on table surface, dam ring height.

Even if the separator classification points, etc.) are the same, the proper balance between them is lost, the layer thickness increases, and the mill vibration value becomes abnormally high.

In this case, as shown in FIG. 3(a) and FIG. 3(b), the inflowing raw material with a thickness of more than the appropriate raw material layer H is transferred to the scraper 100 as shown in G (overflow flow) in the figure. is removed, changes direction and overflows to the outer circumferential side of the rotary table 3,
As mentioned above, it is sent upward by hot air. On the other hand, as shown in F (inclusion flow) in the figure, the raw material up to the raw material layer thickness H has improved pulverizability by water injection from the spray nozzle, and also follows the same trajectory as the conventional one and passes through the auxiliary roller 30.
supplied to In addition, 4A is the biting side of the crushing roller, 4B
indicates the downstream side of the crushing roller, numeral 50 indicates a coarse layer, and numeral 60 indicates a compacted layer.

In the present invention, the spray nozzle is attached to the scraper, but it can also be provided between the auxiliary roller and the crushing roller. It is conventionally known that water is applied to the pulverized raw material using a spray nozzle in a mill, but uniformly injecting water into the compacted layer after the scraper sweeps or after the auxiliary roller as in the present invention improves the pulverizability and improves the quality of the raw material. Changing the natural frequency of the layer (
It is very effective as it is convenient for vibration prevention measures and can reduce the consumption of drying heat sources as much as possible.

Therefore, even if the material layer thickness increases over time, the thickness of the material layer bitten by the grinding roller 4 does not change, the pulverizability is improved, and the natural frequency of the material layer is resonated. Since the vibration can be maintained at a level different from that in the range, vibrations will not increase suddenly and stable operation can continue.

With the above-described configuration and operation, the present invention can eliminate, with the scraper, an increase in the thickness of the raw material layer that is bitten into the grinding roller, 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 explanation, in the vertical crusher of the present invention, even if the layer thickness increases due to changes in raw material properties, the pulverization properties are improved and the auxiliary rollers and crusher are constantly Since the thickness of the raw material layer supplied to the rollers can be maintained almost constant, rapid increases in mill vibration can be suppressed and stable continuous operation can be continued, improving productivity and reducing equipment damage. It also has excellent maintainability, as it prevents damage and extends the life of the device.

[Brief explanation of drawings]

1 to 3 show an embodiment of the present invention, FIG. 1 is a schematic vertical cross-sectional view of the whole, FIG. 2 is an enlarged view of the main part of the crushing part, and FIG. 2(a) is a vertical cross-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). 1... Vertical crusher, 3... Rotating table, 4... Grinding roller, 14...
Annular space part, 20...Casing, 30...
...Auxiliary roller, 32...Hydraulic cylinder, 34...Gap adjuster, 100...Scraper, 1ota...Connecting rod 100b...
Bin, 110... Bin fulcrum, 120...
...Pin support, 130 ... Hydraulic cylinder, 130a ... Piston rod, 140 ... Frame, 150 ... Air seal, 200 ... Spray Nozzle, 210... Header, 220... Water supply piping, H... Raw material layer thickness, F...
...Encroaching 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. The scraper is provided with a scraper disposed on the raw material biting side of the auxiliary roller so as to be movable up and down, and a means for moving the scraper up and down, and a plurality of spray nozzles are arranged on the scraper toward the rear side of the flow of the raw material. A vertical crusher is provided with a pipe for guiding fluid to the spray nozzle.