JP6172577B2 - Vertical crusher - Google Patents

Description

  The present invention relates to the field of pulverization of raw materials, and relates to a vertical pulverizer suitable for finely pulverizing organic raw materials including cement raw materials, slag, clinker, limestone, coal, other inorganic raw materials, and biomass.

Conventionally, a crusher called a vertical crusher (sometimes referred to as a vertical mill or a vertical roller mill) has been widely used as a crusher for crushing coal or the like.
The vertical pulverizer has an excellent characteristic that it can efficiently pulverize a material to be crushed (sometimes simply referred to as a raw material in this specification).
In particular, the vertical crusher of the type called top-up type or air sweep type etc. forms a gas flow that flows while rising upward from the bottom in the machine, classifying mechanism provided in the machine, etc. Therefore, the raw material after pulverization is classified according to the particle size, so that the product having a desired particle size can be taken out as a product.

  However, the vertical crusher has an excellent characteristic that it can efficiently pulverize the raw material, but has a problem that abnormal vibration occurs depending on the type of raw material and the pulverizing condition. It was. Since the abnormal vibration generated in the vertical crusher is induced by various causes, it is necessary to take various measures according to the cause of the vibration, and many countermeasures for preventing abnormal vibration have been proposed.

As described above, there are various causes of abnormal vibration. For example, when the vertical grinding machine is in operation, if the material to be crushed (sometimes referred to as raw material) to be crushed on the rotary table and the grinding roller are slippery, the raw material is caught by the grinding roller. It is known that the ability decreases and the grinding efficiency decreases, and the stick-slip phenomenon is induced to increase the possibility of causing abnormal vibration.
The stick-slip phenomenon is a phenomenon in which the crushing roller slips momentarily on the raw material layer formed on the rotary table and the rotation stops for a moment. This phenomenon is intermittent during operation. If repeated, the rotation of the crushing roller becomes irregular, which causes the vertical crusher to generate vibrations.
The stick-slip phenomenon is particularly likely to occur when the crushing speed of the crushing roller is increased when the raw material on the rotary table and the crushing roller are slippery.

  By the way, many of the vertical crushers of the type referred to as the above-described top-up type or air-swept type use a gas stream to take out a raw material having a desired particle size outside the machine. The raw material that does not have the desired particle size is again supplied on the rotary table and repeatedly pulverized in the machine. In addition, the raw material repeatedly grind | pulverized within the vertical crusher is what is called a circulation raw material by those skilled in the art.

Here, when trying to finely pulverize with a vertical pulverizer, the smaller the desired particle size, the smaller the particle size of the above-mentioned circulating material proportionally.
Fine particles having a small particle size are grouped in the machine and form a powder layer (sometimes called a powder layer or a raw material layer) on the rotary table. The powder layer usually has air inside. It is in the captured state. As a general property of the powder, the smaller the diameter of the powder forming the powder layer, the easier it is to hold a large amount of air therein.
In other words, if the raw material is finely pulverized, the amount of the circulating raw material increases, so the powder layer on the rotary table comes to contain a lot of fine raw materials with a small particle size, and the porosity is high. It becomes a so-called bulky state (a state where the bulk density is low).
Since the bulky powder layer contains a large amount of air, the coefficient of friction of the raw material layer is apparently small. As a result, during operation, the grinding roller becomes slippery and abnormal vibration is likely to occur.

As one of the methods for preventing the abnormal vibration due to the above-mentioned cause, a conventional technique as disclosed in Patent Document 1 is known. The conventional technique disclosed in Patent Document 1 is a technique in which a powder layer on a rotary table is degassed using an auxiliary roller, and once compacted, the raw material is efficiently bitten into the grinding roller.
When the raw material is compacted using an auxiliary roller and then pulverized by a post-pulverization roller, the gas in the raw material is degassed and the pulverization roller is less likely to slip due to the consolidation of the raw material. Play.

Japanese Patent Laid-Open No. 2-174946

The method disclosed in Patent Document 1 described above also has an effect of preventing abnormal vibration.
However, in the technique disclosed in Patent Document 1, it is necessary to arrange an auxiliary roller or the like not directly intended for pulverization in the machine. For this reason, the structure is complicated, maintenance work is increased, and the cost is increased. Therefore, a method capable of reducing abnormal vibration with a simple structure has been demanded.
In the technique disclosed in Patent Document 1, since it is necessary to arrange auxiliary rollers or the like in the machine, the number of crushing rollers is limited. Therefore, depending on conditions, a case where the auxiliary roller cannot be used is assumed.

In recent years, with the increase in the size of the vertical crusher, the size of the rotary table has increased, and the biting speed of the raw material by the crushing roller is also higher than that of the conventionally used small vertical crusher. ,It is rising. Therefore, the raw material and the crushing roller are more slippery than in the past.
Therefore, there has been a demand for a technique that can be used in combination with an auxiliary roller to further enhance the effect of suppressing abnormal vibration.

  The present invention has been made in view of the above-described problems, and relates to a technique of a vertical crusher suitable for reducing abnormal vibration with a simple structure and efficiently pulverizing raw materials.

In order to achieve the above object, a vertical crusher according to the present invention comprises:
(1) By classifying the raw material pulverized by the pulverizing roller on the rotary table by the gas supplied from the lower side of the rotary table and by the classification mechanism arranged above the rotary table,
While taking out the raw material with the desired particle size from the upper part together with the gas,
In the vertical crusher that collects the raw material that has been classified by the classification mechanism and has not been taken out of the machine from the upper part with an internal cone arranged between the rotary table and the classification mechanism, and supplies it again on the rotary table. The guide plate is arranged on the inner cone, and the guide plate is configured to give the raw material supplied from the inner cone to the rotary table a speed in the direction opposite to the rotation direction of the rotary table.

(2) In the vertical crusher according to (1), the guide plate is a spiral guide plate that turns from the outer peripheral side to the inner peripheral side in the direction opposite to the rotation direction of the rotary table.

(3) In the vertical crusher according to (1) or (2), a wear-resistant layer is formed by hardening on the surface of the guide plate opposite to the rotation direction of the rotary table.

(4) In the vertical crusher according to any one of (1) to (3), a new raw material to be introduced into the machine from outside is introduced into the internal cone and supplied onto the rotary table. .

  According to the present invention, a raw material that is repeatedly pulverized in the machine (so-called circulating material), or a new raw material that is introduced into the machine from the outside, is guided by a guide plate arranged in the internal cone to the rotation direction of the rotary table. , It can be put on the rotary table in a state where the speed toward the opposite direction is given, and the biting speed of the raw material by the pulverizing roller can be reduced. Generation of vibration can be suppressed.

  In addition, if a spiral guide plate that rotates in the direction opposite to the rotation direction of the turntable is used, the raw material supplied onto the turntable has a simple configuration and is opposite to the rotation direction of the turntable. It is possible to give a speed in the direction toward.

  Furthermore, according to the present invention, it is possible to extend the life of the guide plate by forming a wear-resistant layer by hardfacing on the surface of the guide plate opposite to the rotation direction of the rotary table.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing explaining the whole structure of a vertical grinder related to embodiment of this invention. It is a figure explaining arrangement | positioning of an internal cone and a guide plate in connection with embodiment of this invention. It is a figure explaining the shape of the guide plate arrange | positioned in the internal cone in connection with embodiment of this invention. It is a figure which concerns on embodiment of this invention and illustrates the behavior of the flow of the raw material in an internal cone notionally. It is a figure which illustrates notionally the behavior of the flow of the raw material which concerns on embodiment of this invention and faces a turntable from an internal cone. It is a figure which illustrates notionally the behavior of the flow of the raw material on a turntable in connection with embodiment of this invention. It is a figure which concerns on the prior art and illustrates the behavior of the flow of the raw material in an internal cone conceptually. It is a figure which illustrates notionally the behavior of the flow of the raw material which concerns on a prior art, and faces an internal cone to a rotary table. It is a figure which illustrates notionally the behavior of the flow of the raw material which flows over a rotary table according to a prior art.

Hereinafter, an example of a preferred embodiment of the present invention will be described in detail as a first embodiment (sometimes referred to as a first embodiment) based on the drawings and the like.
FIG. 1 to FIG. 6 relate to an embodiment of the present invention and show a preferred example thereof. FIG. 1 is a cross-sectional view for explaining the overall configuration of a vertical crusher.
2 is a view for explaining the arrangement of the inner cone and the guide plate, FIG. 2 (1) is a view observed from above, and FIG. 2 (2) is a view observed from the side. 3 is a view for explaining the shape of the guide plate disposed in the inner cone, FIG. 3 (1) is a view observed from above, and FIG. 3 (2) and (3) are B part and C part, respectively. FIG. 4 to 6 conceptually show the flow behavior of the raw material, FIG. 4 shows the flow of the raw material in the inner cone, FIG. 5 shows the flow of the raw material from the inner cone toward the rotary table, and FIG. 6 shows the rotation. It shows the flow of raw materials on the table.
7 to 9 conceptually show the flow behavior of the raw material according to the prior art, and show an example of a case in which the guide plate is not provided in the internal cone, and FIG. 8 shows the flow of the raw material in the internal cone, FIG. 8 shows the flow of the raw material from the internal cone toward the rotary table, and FIG. 9 shows the flow of the raw material on the rotary table.

FIG. 1 shows a vertical crusher 1 according to a first embodiment.
The vertical pulverizer 1 shown in FIG. 1 is a vertical pulverizer 1 of a type called an air sweep type or the like, and uses a gas air flow and a classification mechanism 16 provided therein to make a desired While the raw material having a particle diameter is taken out of the machine, the raw material that does not have the desired particle diameter is again supplied onto the rotary table 2 and repeatedly pulverized by the pulverizing roller 3.

Hereinafter, the structure of the vertical crusher 1 will be described.
The vertical pulverizer 1 shown in FIG. 1 is driven by casings 1B and 1A that form the outline of the vertical pulverizer 1, a speed reducer 2B installed at the lower part of the vertical pulverizer 1, and a drive motor (not shown). A rotary table 2 and a conical crushing roller 3 are provided.
In the vertical crusher 1 shown in FIG. 1, as shown in FIG. 6, four crushing rollers 3 are arranged on the rotary table 2 with the phase shifted by 90 degrees on the outer peripheral portion thereof. It has a structure. The vertical pulverizer 1 is a variable speed vertical pulverizer 1 that includes an inverter power supply as a driving power source for a drive motor (not shown) and can freely change the rotation speed of the rotary table 2 during operation.

The vertical crusher 1 has a fixed primary classifying blade 14 (generally also referred to as a guide vane 14), a rotary type classifying blade 13 and a rotary shaft 15 in the upper part of the machine. The classification mechanism 16 comprised by these is provided.
The rotary classification blade 13 is connected to the rotary shaft 15 and is driven by a drive motor (not shown) installed on the top of the vertical crusher 1 to rotate freely. A fixed primary classifying blade 14 is arranged on the side.

  The vertical crusher 1 is also referred to as a gas supply port 33 for introducing gas below the rotary table 2 and a lower outlet 34 (discharge chute 34) for taking out an extremely heavy material. And an upper outlet 39 through which a product (a raw material that has been pulverized to a desired particle size) can be taken out together with the gas, above the rotary table 2.

  In the vertical pulverizer 1, an annular passage 30 (also referred to as an annular passage 30) is formed between the outer peripheral side portion of the rotary table 2 and the lower casing 1 </ b> A of the vertical pulverizer 1. The gas supplied from the gas supply port 33 passes through the annular passage 30, rises, blows up inside the machine, passes through the classification mechanism 16, and then flows toward the upper outlet 39. .

The vertical crusher 1 shown in FIG. 1 has the above-described configuration, and introduces gas (air in the first embodiment) from the gas supply port 33 during operation, so that the primary classifying blade 14 from below the rotary table 2 is introduced. In addition, an air flow of gas flowing through the rotary classification blade 13 and flowing to the upper outlet 39 is generated.

Here, in the vertical crusher 1 according to the first embodiment of the present invention, as shown in FIG. 1, an internal cone 22 is arranged between the rotary table 2 and the classification mechanism 16.
The inner cone 22 has a shape that is a reverse of the truncated cone shape, and its upper part is annular and opens upward, and the above-described primary classifying blade 14 is formed on the outer periphery of the upper end. A plurality of them are arranged at equal intervals.
Further, in the first embodiment of the present invention, the cone lower end 24 serving as the lower part of the inner cone 22 is cylindrical and has a shape that opens downward toward the center of the turntable 2.

Then, on the inner side surface of the inner cone 22, as shown in FIG. 2, the rotation direction of the turntable 2 from the outer peripheral side (the upper side of the inner cone 22) to the inner peripheral side (the lower side of the inner cone 22). A plurality of rows of gently spiral (sometimes referred to as spiral) guide plates 20 extending while turning in the opposite direction.
In the first embodiment, as shown in FIG. 2 (1), eight rows of guide plates 20 are provided, and each guide plate 20 shows its detailed shape in FIG. 3 (2). The inner cone 22 has a constant height (50 mm in the first embodiment) and extends while gently drawing a spiral shape on the inner surface of the inner cone 22.

In the first embodiment, as shown in FIG. 3 (3), the spirally extending guide plate 20 has a two-layer structure, and the surface of the guide plate 20 on the rotation direction side of the rotary table is the substrate 20B (first In the embodiment, the thickness was 6 mm), and a wear-resistant layer 20A (thickness: 3 mm in the first embodiment) was formed on the surface in the direction opposite to the rotation direction of the rotary table.

Hereinafter, the outline of the crushing behavior and the like of the vertical crusher 1 will be described.
The raw material introduced into the vertical crusher 1 from the outside is introduced into the internal cone 22 through the raw material introduction chute 35 and is combined with the circulating raw material to be described later. To be supplied. The raw material supplied from the cone lower end 24 to the vicinity of the center of the turntable 2 is moved on the turntable 2 from the center side of the turntable 2 toward the outer periphery side by being influenced by the rotation of the turntable 2. The powder layer is formed while being bitten by the crushing roller 3 and pulverized.

The raw material pulverized by the pulverizing roller 3 further moves to the outer peripheral side of the rotary table 2, gets over the dam ring 17, reaches the annular passage 30, is blown up there, and rises in the casing 1 </ b> B.
Of the raw materials blown up by the gas, the raw material having a relatively large diameter deviates from the gas flow when blown up and returns again to the annular passage 30 side or the upper side of the rotary table 2. Move in the direction.
In addition, among the raw materials that have reached the annular passage 30, the extremely heavy raw material does not blow up there even if it reaches the annular passage 30, and falls as it is, so that the lower portion in the lower part of the vertical crusher 1 It is discharged out of the machine through the outlet 34.

On the other hand, among the raw materials blown up by the gas, the raw material having a relatively small diameter is conveyed together with the gas to the primary classification blade 14 and passes through the primary classification blade 14.

Of the raw materials that have passed through the primary classification blade 14, the raw material having a desired particle size passes through the rotary classification blade 13, passes through the classification mechanism 16, and is taken out as a product from the upper outlet 39. It is.
In addition, the raw material that has not been finely pulverized to the desired particle size among the raw materials that have passed through the primary classifying blades 14 falls into the internal cone 22 and is then introduced into the machine via the raw material charging chute 35 described above. Combined with the new raw material thus prepared, it is supplied again onto the rotary table 2 and is crushed by being caught between the crushing roller 3 and the rotary table 2.

Here, in the first embodiment of the present invention, the spiral guide plate 20 is disposed in the inner cone 22.
The raw material that has fallen into the inner cone 22 is guided by a spirally extending guide plate 20 disposed on the inner peripheral surface of the inner cone 22 and turns downward while spirally turning from the outer peripheral side toward the inner peripheral side. And moves to the cone lower end 24 side. And the raw material which flowed to the cone lower end 24 is supplied on the turntable 2 in the state where the speed which goes to the opposite direction side with respect to the rotation direction of the turntable 2 was given.

The raw material flow S is shown in FIGS.
As shown in FIG. 4, the raw material charged into the inner cone 22 is guided by the spiral guide plate 20, and the inner surface of the inner cone 22 is moved from the outer peripheral side toward the inner peripheral side. It flows and moves in the direction of the center, spiraling in the direction opposite to the rotation direction.

FIG. 5 shows a case where the raw material flow S is observed from the side surface.
The raw material charged into the inner cone 22 is guided by the spiral guide plate 20, moves while swirling from the upper side to the lower side of the inner cone 22, and is supplied onto the rotary table 2. .

FIG. 6 shows a raw material flow S on the turntable 2.
Originally, the raw material supplied on the turntable 2 is moved from the center side of the turntable 2 to the outer peripheral side while being flown toward the turntable side of the turntable 2 by being influenced by the rotation of the turntable 2. .
However, in 1st Embodiment by this invention, when the raw material is supplied to the turntable 2 from the cone lower end 24, the state which gave the speed which goes to the opposite direction side with respect to the rotation direction of the turntable 2 was given. It is in.
Therefore, the raw material supplied onto the turntable 2 starts to flow from the cone lower end 24 toward the side opposite to the rotation direction of the turntable 2 and toward the direction opposite to the rotation direction of the turntable 2. And the speed in the direction of traveling while flowing toward the rotation direction of the turntable 2 are moved in a state where they are influenced by each other.

  As a result, with regard to the raw material flow S on the rotary table 2, the speed at which the raw material is bitten by the pulverizing roller 3 is reduced as compared with the conventional vertical pulverizer. It is difficult to slip between the powder layer and the occurrence of abnormal vibration.

For comparison, examples according to the prior art are shown in FIGS.
Unlike the first embodiment described above, in the prior art, when supplying a raw material onto the turntable 2, the supplied raw material is positively given a speed in the direction opposite to the rotation direction of the turntable 2. Not.
Speaking of the speed when the raw material is bitten by the crushing roller 3, unlike the above-described first embodiment according to the present invention, the raw material supplied onto the rotary table 2 is on the opposite side to the rotation direction of the rotary table 2. Since it is not reduced by giving the speed of the direction to go to, it becomes faster compared to the case of the first embodiment.
Accordingly, the speed at which the raw material is bitten by the pulverizing roller 3 is not reduced, and the possibility of slipping between the pulverizing roller 3 and the powder layer cannot be suppressed, so that abnormal vibration can be reduced. Not.

In the first embodiment of the present invention, the wear-resistant layer 20 </ b> A is formed by applying hardening to the surface of the guide plate 20 opposite to the rotation direction of the turntable 2.
When a spiral guide plate swirling in the direction opposite to the rotation direction of the turntable 2 is arranged on the inner surface of the inner cone 22 from the outer peripheral side to the inner peripheral side, when the raw material flows through the inner cone 22 The guide plate 20 flows side by side along the wear-resistant layer 20 </ b> A that is a surface opposite to the rotation direction of the turntable 2.
Therefore, the life of the guide plate 20 can be extended by forming the wear-resistant layer 20 </ b> A on the surface of the guide plate 20 opposite to the rotation direction of the turntable 2.

In the first embodiment of the present invention, it is possible to effectively give the raw material supplied onto the turntable 2 with a speed that is directed in the direction opposite to the rotation direction of the turntable 2 with a simple configuration. As a preferable configuration that can be achieved, the configuration in which the spiral guide plate 20 is disposed inside the inner cone 22 is shown.
However, the configuration of the guide plate 20 that can be applied to the present invention is not limited to this, and can be changed without departing from the technical idea of the present invention, and other shapes of the guide plate 20 may be used. For example, by arranging a guide plate inclined at a certain angle in the cone lower end 24, the raw material supplied onto the rotary table 2 is effective in the direction in the direction opposite to the rotation direction of the rotary table 2. It is good also as a structure to give.

  As described above, the vertical pulverizer according to the present invention relates to a vertical pulverizer suitable for finely pulverizing raw materials.

DESCRIPTION OF SYMBOLS 1 Vertical crusher 2 Rotary table 3 Crushing roller 13 Rotating classification blade 14 Primary classification blade 15 Rotating shaft 16 Classification mechanism 17 Dam ring 20 Guide plate 20A Wear-resistant layer 20B Substrate
22 Inner cone 1A Lower casing 1B Upper casing 2B Reducer 30 Annular passage (annular space)
33 Gas supply port 35 Raw material input port 39 Upper outlet

Claims (4)

By classifying the raw material crushed by the crushing roller on the rotary table with a classification mechanism disposed above the rotary table by blowing up with the gas supplied from below the rotary table,
While taking out the raw material with the desired particle size from the upper part together with the gas,
In the vertical crusher that collects the raw material that has been classified by the classification mechanism and has not been taken out of the machine from the upper part with an internal cone arranged between the rotary table and the classification mechanism, and supplies it again on the rotary table. ,
A vertical crusher in which a guide plate is arranged on an inner cone and the guide plate gives a speed in the direction opposite to the rotation direction of the rotary table to the raw material supplied from the inner cone to the rotary table.   The vertical crusher according to claim 1, wherein the guide plate is a spiral guide plate that turns from the outer peripheral side to the inner peripheral side in a direction opposite to the rotation direction of the rotary table.   The vertical grinder according to claim 1 or 2, wherein a wear-resistant layer is formed on the surface of the guide plate opposite to the rotation direction of the rotary table by hardening.   The vertical crusher according to any one of claims 1 to 3, wherein a new raw material charged into the machine from the outside is fed into the internal cone and supplied onto a rotary table.

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