JP7615796B2 - Vertical crusher and method for diagnosing crushing rollers thereof - Google Patents

Description

This relates to a vertical pulverizer for pulverizing solid materials such as coal, limestone, cement raw materials, clinker, slag, oil coke, and other inorganic and organic raw materials.

A pulverizer is a device that crushes coal, limestone, cement raw materials, etc. into fine powder. A vertical pulverizer presses a crushing roller against a disk-shaped table using hydraulic or centrifugal force, and compresses and crushes the material between the crushing roller and the rotating table. This type of vertical pulverizer is widely used due to its characteristics of low power consumption per unit amount of material crushed and efficient crushing.

When raw materials are fed into the vertical crusher through a chute, they pass through an internal cone and fall to the center of the rotating table, where they are pushed to the outer periphery by centrifugal force, and are caught between the crushing roller and the rotating table, where they are crushed by compression and shear force. Inside this crusher, there is a gap between the outer periphery of the rotating table and the casing, and gas is ejected from this gap.

The crushed raw material is carried upward by the gas current toward the gap between the outer periphery of the rotating table and the casing. In this way, it is sent to a classifier (separator) attached above, where it is classified, and finally collected outside as a product. Also, raw materials that are too large to be crushed sufficiently cannot pass through the classifier, and are fed back onto the rotating table again to be crushed.

In this way, the gas flow is used to transport the crushed material to the top of the machine and remove it, while crushed material with a particle size that is too large to be transported by the gas flow falls from the rotating table and is collected from a discharge chute below the machine. The collected crushed material is then fed back onto the rotating table from above the machine by a bucket elevator, and is repeatedly crushed until it reaches the desired particle size.

In order for a vertical crusher to perform its crushing function, it is important that the crushing parts (especially the roller tires) maintain their specified shape, but as the crushing operation continues, wear progresses over time and the shape of the roller tires becomes distorted.

Depending on the location and type of raw material, grinding conditions, etc., the raw material fed into the vertical grinding mill flows unevenly onto the rotating table, resulting in an uneven layer thickness of the raw material layer. As a result, the load on the roller tires of the multiple grinding rollers fixed inside the casing varies depending on the installation location of the grinding rollers, and the degree of wear of each grinding roller also varies. When the roller tires wear out in this way, the raw material is not crushed sufficiently, and the quality and quantity of the crushed material obtained decreases.
In addition, extra energy is consumed to re-pulverize the material that was not sufficiently pulverized by the classifier. Even if re-pulverization is performed, it is difficult to obtain pulverized material of the desired particle size with such worn roller tires.
For this reason, as disclosed in Patent Document 1, a structure is adopted in which the roller tires of the crushing roller can be replaced when wear progresses.

JP 2007-061684 A

However, until now, roller tire wear has been considered an important control value for safe operation, but it could only be measured when the vertical crusher was stopped, which was inefficient work and required estimation with little information without the ability to check progress along the way. This posed a risk of unexpected operation stoppages and sudden maintenance work. In order to avoid these risks, roller tires were replaced before their expected lifespan, even though they still had plenty of life left.

In view of the above problems, the problem that the present invention aims to solve is to provide a vertical crusher and a diagnostic method that can obtain information on the amount of wear on the roller tires without stopping the operation of the vertical crusher.

In order to solve the above problems, as a first means, a vertical crusher is provided in which a rotatable crushing roller is disposed on a rotating table, and raw materials are crushed by compression and shear force by being caught between the rotating table and the crushing roller,
a cylindrical partition member is provided which extends from above the dam ring of the rotary table along the side surface of the lower casing to an inner cone;
The objective of the present invention is to provide a vertical crusher comprising: a lattice- or fence-shaped discharge port arranged at a position of the partition member after the crushing rollers are engaged with the partition member, the same number of discharge ports as the crushing rollers; and vanes extending from the lower end of the partition member toward a classifier on the outer surface of the partition member, the same number of discharge ports as the crushing rollers. Thus, gas blow-up passages are formed between the vanes across the annular gap between the lower casing and the partition member , the same number as the roller tires, and the crushed material is blown upward along the vanes through the gas blow-up passages corresponding to each roller tire and transported to the classifier .
According to the first means, each crushing roller is provided with an outlet for discharging crushed material, and a gas blow-up passage can be formed by forming vanes on the outer surface of a cylindrical partition member along the gas flow from the outlet toward the top of the vertical crusher. This gas blow-up passage discharges crushed material that has become large enough to pass through the openings of each outlet corresponding to each crushing roller, and guides it to the classifier, thereby preventing the consumption of unnecessary energy caused by the collision of the ascending air current and the natural falling current.

In order to solve the above problem, as a second means, the gas blow-up passage is formed in a spiral shape extending upward along the outer surface of the partition member,
The object of the present invention is to provide a vertical crusher as described in the first means, in which the crushed material crushed by each crushing roller is guided to a classifier.
According to the second means, a vane plate is provided for each outlet corresponding to each crushing roller to form a gas blow-up passage, through which crushed material having a particle size large enough to pass through the opening of each outlet corresponding to each crushing roller is discharged and guided to a classifier, thereby preventing the consumption of unnecessary energy caused by the collision of an ascending air current and a gravity falling current.
In addition, since a gas blow-up passage corresponds to each crushing roller, the progress of crushing by each crushing roller is reflected in the atmosphere in the gas blow-up passage.

In order to solve the above problems, the third means is to provide a vertical crusher as described in the first or second means, which is provided with a dust concentration measuring mechanism for measuring the dust concentration indicating the concentration of the crushed material in each gas blow-up passage corresponding to each crushing roller.
According to the third means, the dust concentration indicating the concentration of the crushed material in each gas blow-up passage is continuously measured by a dust concentration measuring mechanism provided in each gas blow-up passage corresponding to the crushing roller, thereby making it possible to estimate the progress of crushing in each crushing roller.

In order to solve the above problems, a fourth aspect of the present invention provides a diagnostic method for a crushing roller used in the vertical crusher according to the first aspect of the present invention, comprising the steps of:
a step of continuously measuring the concentration of finely pulverized material pulverized by the pulverizing roller in each gas blow-up passage by a dust concentration measuring mechanism for measuring a dust concentration indicating the concentration of the pulverized material provided in each gas blow-up passage;
Another object of the present invention is to provide a diagnostic method for a crushing roller, comprising a step of comparing the measured concentration with a predetermined reference value to estimate the condition of the crushing roller.
According to the fourth means described above, the dust concentration indicating the concentration of the crushed material in each gas blow-up passage is continuously measured by a dust concentration measuring mechanism provided in the gas blow-up passage corresponding to each crushing roller, so that the progress of crushing in each crushing roller can be confirmed in real time and the condition of each crushing roller can be estimated, making it possible to replace worn roller tires of the crushing rollers at the appropriate time.

According to the present invention, by providing a gas blow-up passage corresponding to the roller tires of each crushing roller and a dust concentration measuring mechanism within the gas blow-up passage, not only is it possible to prevent the waste of energy caused by the collision of the ascending air current and the natural falling current, but it is also possible to replace worn roller tires of the crushing rollers at the appropriate time.

FIG. 2 is a side cross-sectional view of the vertical crusher of the present invention. FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1 . FIG. 2 is a perspective view illustrating the arrangement of vane plates in the vertical crusher of the present invention. FIG. 1 is a side cross-sectional view of a conventional vertical crusher.

Below, an embodiment of the present invention will be described with reference to the drawings. After explaining FIG. 4 as the prior art, the present invention will be described with reference to FIGS. 1 to 3.

[Conventional vertical crusher 1]
4 is a side cross-sectional view of a conventional vertical crusher 1. As shown in the figure, the conventional vertical crusher 1 is equipped with a reducer installed below an upper casing 2A and a lower casing 2B forming an outer shell, a rotary table 8 driven by a drive motor (not shown), and a crushing roller. In addition, a funnel-shaped inner cone 6 is arranged above the rotary table 8, and a classifier 5 is fixed to the upper part of the inner cone 6. A cylindrical raw material supply port 3 is arranged coaxially with the center of the classifier 5 and the center of the lower opening of the inner cone 6, and the raw material input from the raw material supply port 3 is piled up on the rotary table 8. The piled up raw material is caught between the roller tire 7 of the crushing roller and the rotary table 8 and crushed by compression and shear force.
Furthermore, the crushed material is transported upward by the gas flow introduced from the gas inlet 9 below the rotating table 8, and only the material with the desired particle size is taken out together with the gas from the upper outlet 4 at the top of the vertical crusher via the classifier 5.

[Vertical crusher 11 of the present invention]
1 is a side cross-sectional view of a vertical crusher 11 of the present invention. The vertical crusher 11 of the present invention is originally equipped with a plurality of crushing rollers, but the illustration shows only the roller tires 17, the discharge port 24, and the vanes 10 of one set of crushing rollers.
In an embodiment of the present invention, a cylindrical partition member 13 is provided that extends from above the dam ring of the rotating table 18 along the side of the lower casing 12B to the classifier 15, surrounds the circumference of the rotating table 18, and surrounds the space between the rotating table 18 and the internal cone 16.
The upper end of the cylindrical partition member 13 is provided with a small gap so that it does not come into contact with the internal cone 16, and the lower end is provided with a small gap so that it does not come into contact with the rotary table 18, and the partition member 13 is fixed to the side surface of the lower casing 12B by a support member (not shown). The cylindrical partition member 13 is made of a steel material having the same strength as the casing, and its outer diameter is the same as that of the rotary table.

The cylindrical partition member 13 is provided with a discharge port 24, which is located at a position after the roller tires 17 of the crushing roller are bitten (anti-biting position), and the crushed material that has been crushed to a predetermined particle size is discharged from the discharge port 24 and blown upward along the blades 10 to the classifier 15. Thereafter, the crushed material (product) is taken out from the upper outlet 14 through the classifier 15.
The blade plate 10 is formed to extend in a spiral shape from the opposite bite side on the rotating table 18 to the classifier 15 above, while rotating along the outer surface of the partition member 13, with the same inclination angle as the air direction control plate 25.
As shown in FIG. 1, the airflow control plates 25 are rectangular plates arranged in an upward inclination from the left side to the right side, and a plurality of them are provided at regular intervals along the annular gap.

Fig. 2 is a cross-sectional view taken along line A-A in Fig. 1 when there are four crushing rollers. As shown in Fig. 2, the partition member 33 is provided with the same number of discharge ports 34 as the roller tires 37 so as to correspond to the roller tires 37 of the crushing rollers. In the annular gap between the lower casing 32B and the partition member 33, the partition member 33 is provided with the same number of vanes 30 as the discharge ports 34 so as to correspond to the discharge ports 34 along the outer surface of the partition member 33.
In other words, since there are the same number of roller tires 37, discharge ports 34, and vanes 30, the same number of gas blow-up passages 36, which are passages between the vanes 30, are also formed in the annular gap between the lower casing 32B and the partition member 33, and the crushed material crushed by each roller tire 37 of the crushing roller is blown upward and transported through the corresponding gas blow-up passages 36.

Figure 3 shows a perspective view illustrating the arrangement of the vanes in the vertical crusher of the present invention. The vanes 40 are located in the annular gap between the lower casing 42B and the partition member 43, and are formed in a spiral shape starting from the lower right end of the fence-like or lattice-like discharge port 44, and rotating upward along the outer surface of the partition member 43 at the same angle as the inclination angle of the air direction control plate 45.

The opening of the discharge port 44 is shaped like a fence or a lattice so that only fine powder can pass through, and raw materials with large particle sizes that cannot pass through the slits or mesh are not discharged but remain on the rotating table and can be crushed again. In other words, by adjusting the opening size of the discharge port 44, it is possible to adjust the particle size to a certain degree to the desired particle size. In addition, crushed materials that could not pass through the classifier are supplied again to the rotating table via the internal cone.
In this way, the frequency of natural falling flows occurring when pulverized material falls without being able to pass through the classifier can be reduced, thereby preventing the waste of energy caused by the collision of the rising air current toward the classifier, which occurs in conventional vertical pulverizers, with the natural falling flow caused by pulverized material falling without being able to pass through the classifier.

2, since the gas blow-up passage 36 corresponds to each roller tire 37 of the crushing roller, the atmosphere in the gas blow-up passage 36 can reflect the progress of crushing by the roller tire 37. Therefore, a dust concentration meter (not shown) is provided in the gas blow-up passage 36 as a dust concentration measuring mechanism, and the progress of crushing by each roller tire 37 can be estimated by measuring the dust concentration indicating the concentration of the crushed material in the gas blow-up passage 36. This dust concentration meter is preferably of the light scattering type or light transmission type, and it is determined whether the value measured by the dust concentration meter in the gas blow-up passage 36 is higher or lower than a predetermined reference value. In other words, the dust concentration is higher when the crushing is performed normally.
At this time, since the dust concentration in the gas blow-up passage 36 varies depending on the amount of raw material supplied, the predetermined reference value is determined taking into consideration the amount of raw material supplied.
Further, the dust concentration measuring mechanism may be of a type that does not require gas sampling as described above, but may also be of a type that measures the dust concentration in gas sampled from inside the gas blow-up passage 36 by a collector.

As an example, in a vertical grinding machine equipped with gas blow-up passages a to d corresponding to roller tires a to d of a grinding roller, the results of judging whether the value measured by a dust concentration meter in the gas blow-up passage was higher or lower than a predetermined reference value are summarized in Table 1.

When the measurement result of the dust concentration is A, the concentrations in each gas blowing passage are all higher than the predetermined reference value, so that the operating condition is determined to be stable, and the corresponding roller tires a to d can be diagnosed as being in a normal condition with no wear.
Furthermore, when the dust concentration measurement result is B, the operating condition is determined to be unstable because the concentration in each gas blowing passage varies (some high and some low) from a predetermined standard value, and roller tires b and c, which showed dust concentrations lower than the standard value, can be diagnosed as being undergoing wear.
If the dust concentration measurement result is C, the concentrations in each gas blowing passage are all lower than the predetermined reference value, so it is determined that the operating condition is unstable and that the corresponding roller tires a to d are experiencing wear.

As described above, the degree of wear of the roller tires of each crushing roller can be diagnosed from the information obtained by measuring the dust concentration in the gas blow-up passage while the vertical crusher is in operation. Until now, in order to ensure stable operation, roller tires have been replaced before the expected lifespan even though there was still a sufficient life left, but this embodiment makes it possible to determine which roller tires should be replaced based on the degree of wear, and to perform the replacement work at an appropriate time without waste.
Furthermore, in order to prevent unexpected maintenance work from occurring, maintenance work can be planned without stopping the operation of the vertical crusher.

In addition to the above, it is possible to select and discard the configurations described in the above embodiments or to change them to other configurations as appropriate without departing from the spirit of the present invention.

1 Conventional vertical pulverizer 2A, 12A Upper casing 2B, 12B, 32B, 42B Lower casing 3 Raw material inlet 4, 14 Upper outlet 5, 15 Classifier 6, 16 Internal cone 7, 17, 37 Roller tire 8, 18 Rotary table 9, 19 Gas inlet 10, 30, 40 Blade plate 11 Vertical pulverizer of the present invention 13, 33, 43 Partition member 24, 34, 44 Exhaust port 25, 45 Airflow control plate 36 Gas blow-up passage

Claims (4)

A vertical crusher has a rotating table and a rotatable crushing roller disposed on the rotating table, and crushes raw materials by being caught between the rotating table and the crushing roller through compression and shear force,
a cylindrical partition member is provided which extends from above the dam ring of the rotary table along the side surface of the lower casing to an inner cone;
A vertical crusher comprising : a lattice-shaped or fence-shaped discharge outlet arranged at a position of the partition member after the crushing rollers are engaged with the partition member, the same number of discharge outlets as the crushing rollers; and vanes extending from the lower end of the partition member toward a classifier on the outer surface of the partition member, the same number of discharge outlets as the crushing rollers, thereby forming gas blow-up passages between the vanes in the same number as the roller tires across the annular gap between the lower casing and the partition member, and the crushed material is blown upward along the vanes through the gas blow-up passages corresponding to each roller tire and transported to the classifier . The gas blow-up passage is formed in a spiral shape extending upward along the outer surface of the partition member,
2. The vertical crusher according to claim 1, wherein the crushed material crushed by each crushing roller is guided to a classifier. 3. The vertical crusher according to claim 1, further comprising a dust concentration measuring mechanism for measuring a dust concentration indicating a concentration of the crushed material in each of the gas blow-up passages corresponding to each of the crushing rollers. A diagnostic method for a crushing roller used in the vertical crusher according to claim 1, comprising:
a step of continuously measuring the concentration of finely pulverized material pulverized by the pulverizing roller in each gas blow-up passage by a dust concentration measuring mechanism for measuring a dust concentration indicating the concentration of the pulverized material provided in each gas blow-up passage;
The method for diagnosing a crushing roller includes a step of comparing the measured concentration with a predetermined reference value to estimate the condition of the crushing roller.

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