JP2006102691A - Vertical mill and crushing system for crushed sand production - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vertical mill and a crushing system for crushed sand production capable of performing stable operation without lowering crushing efficiency even in producing crushed sand using raw stones with fluctuation in attached moisture as the raw material. <P>SOLUTION: Crushed matter is separated from fine powder and fine powder is efficiently taken out of an upper taking-out port together with gas by evaporating moisture attached to the raw material and reducing the moisture, by introducing heated gas from the lower part of the vertical mill. This operation reduces an amount of fine powder attached to crushed matter taken out of a lower taking-out port, to stabilize the amount of the crushed matter taken out of the lower taking-out port. The reduced amount of fine powder in the crushed matter taken out of the lower taking-out port hardly causes clogging of a sieve, and stabilizes operation even when a sieve type classifier like a vibration sieve is used. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vertical crusher and a grinding system that mainly produce sandstone by pulverizing raw stones such as sandstone, granite, andesite, serpentinite, etc., and in particular, produces crushed sand using raw stones with varying adhesion moisture. The present invention relates to a vertical pulverizer and a pulverization system suitable for manufacturing crushed sand.

  Conventionally, a pulverization system as described in Patent Document 1 has been used to pulverize raw stones such as hard sandstone, granite, andesite, and serpentine to produce crushed sand.

Japanese Patent Laid-Open No. 7-51591

  The pulverization system for producing crushed sand disclosed in Patent Document 1 is a method of pulverizing raw crushed material by primary crushing and secondary crushing and then crushing the crushed crushed material by a vertical crusher comprising a rotary table and a plurality of crushing rollers. To do. Then, the pulverized product pulverized by the vertical pulverizer is sieved with a vibrating sieve, the sieved product is returned to the vertical pulverizer, the under sieve is classified into fine powder and crushed sand by an air classifier, and after classification Crushed sand is washed with a wet classifier to make a product.

Hereinafter, a general structure of a conventional vertical grinder will be briefly described.
The above-described conventional vertical crusher includes a casing that forms an outline of the vertical crusher, a rotary table that is driven by a drive source such as an electric motor, and an outer peripheral portion of the upper surface of the rotary table in a circumferential direction. A plurality of crushing rollers disposed at equally-divided positions, and the crushing rollers are connected to a hydraulic cylinder via an arm pivotally attached to the casing, It is structured to rotate by being pressed in the direction of the upper surface of the rotary table by operation and being driven via the raw material on the upper surface of the rotary table.

  Above the rotating table of the casing, a raw material charging port is provided for charging the raw material on the upper surface of the rotating table.When the raw material is charged from the raw material charging port to the upper surface of the rotating table, the charged raw material is: The crushed raw material is crushed by being caught between the upper surface of the rotary table and the pulverizing roller, and the crushed raw material falls over the dam ring provided around the outer edge of the upper surface of the rotary table and falls below the rotary table. Then, it is taken out as a pulverized product from the lower outlet provided below the rotary table to the outside of the vertical crusher.

The casing is provided with a gas inlet for introducing gas below the rotary table, and an upper outlet for discharging the gas above the rotary table.
During operation of the vertical crusher, gas is introduced from the gas introduction port, and a gas flow from the lower side to the upper side of the rotary table is generated in the casing. The small fine powder is blown up, moved up in the casing, and taken out as fine powder dust from the upper outlet.

  The pulverized product taken out from the lower outlet is transported to a classification device such as a vibrating sieve and classified into coarse particles (sometimes referred to as coarse powder) and fine particles (sometimes referred to as fine powder). Sorted and separated. After the fine powder is taken out, the fine powder is removed by means such as pneumatic classification or water washing to obtain a product as crushed sand, and the coarse particles are again fed into a vertical crusher where they are pulverized again.

  The pulverized product pulverized by the above-described vertical pulverizer has a rounded particle shape with rounded corners, so that it has a shape close to natural sand, and thus becomes crushed sand with high added value.

Here, even if the rough stones to be crushed by the vertical grinder are the same kind of rough stones, the amount of adhering water is generally different depending on the storage condition and the like.
However, when a rough stone with a large amount of water is crushed with a conventional vertical crusher, a pulverized product with a large amount of fine powder on the surface is taken out from the lower outlet, and the amount of moisture When pulverizing raw stones with a small amount, a lot of fine powder is removed by the gas introduced from the gas inlet, and it is removed as fine dust from the upper outlet. The phenomenon of being taken out from the lower outlet occurs.
For this reason, there is a problem that the amount of pulverized product taken out from the lower outlet is not stable due to the amount of water adhering to the raw stone put into the vertical crusher.

  In addition, when a pulverized product with a large amount of fine powder adhering to the surface is classified by a classifier such as a vibrating sieve, the screen (sometimes referred to as a screen) is likely to be clogged, resulting in stable classification. Since it cannot be maintained, it can cause problems that the operation of the grinding system becomes unstable. There is a measure to calculate the screen area reduction due to clogging in advance and increase the screen area. However, if the system is operated for a long time only to increase the size of the classifier, The crushing system becomes unstable due to clogging.

  As a method of removing fine powder adhering to the surface of the pulverized product taken out from the lower outlet, a method of washing the pulverized product with water is generally used, but if the pulverized product pulverized with a vertical grinder is washed with water, Waste dehydrated cake needs to be processed and water treatment equipment is required, so the overall equipment becomes large and the efficiency decreases.

  On the other hand, as another problem, a raw material with a large amount of moisture has a problem that the raw material friction angle at the time of pulverization becomes small and the pulverization efficiency is lowered, and the pulverization roller and the rotary table are easily worn.

  The present invention has been made in view of the above problems, and stable operation without reducing the crushing efficiency of the vertical crusher even when producing crushed sand using raw stones with variations in adhering moisture as a raw material. The present invention relates to a vertical crusher and a crushing system for producing crushed sand.

In order to solve the above problems, a vertical crusher for producing crushed sand according to the present invention is:
(1) A lower outlet and a gas inlet for taking out the pulverized product are provided below the rotary table, and an upper outlet is provided above the rotary table for discharging the gas,
While the raw stone put on the rotary table is pulverized between the rotary table and the pulverizing roller, a hot gas is introduced from the gas inlet, whereby the pulverized product blown up by the hot gas is removed from the upper outlet. The pulverized product that is not blown up by the hot gas is dropped into the lower outlet and taken out.

Moreover, the grinding system for producing crushed sand according to the present invention is:
(2) A lower outlet and a gas inlet for taking out the pulverized product are provided below the rotary table, and an upper outlet is provided above the rotary table for discharging the gas.
While the raw stone put on the rotary table is pulverized between the rotary table and the pulverizing roller, a hot gas is introduced from the gas inlet, whereby the pulverized product blown up by the hot gas is removed from the upper outlet. It is provided with a vertical pulverizer for producing crushed sand, which is taken out as fine powder from the hot gas and dropped to the lower outlet, and a sieve classifier.
The pulverized product taken out from the lower outlet in the vertical pulverizer is classified by the sieve classifier, and the pulverized product having a predetermined particle size or less is taken out as crushed sand. The mold was pulverized again by pulverization.

(3) The pulverization system according to (2), further comprising a generator for supplying electric power for driving the vertical pulverizer, wherein the hot gas introduced from the gas inlet is discharged from the generator. The gas was heated using heat.

(3) In the pulverization system according to (2) or (3), a part of the crushed sand taken out from the sieve classifier is again put into a vertical pulverizer and pulverized.

  As described above, according to the vertical crusher for crushed sand production according to the present invention, when pulverizing the raw stone with a large amount of moisture, it was attached to the raw material due to the effect of the hot gas introduced from the gas inlet. Since the moisture is reduced by evaporation, the pulverized product and the fine powder are separated, and the fine powder is easily taken out together with the gas from the upper outlet. Therefore, fine powder is difficult to adhere to the pulverized product taken out from the lower outlet, and as a result, the amount of the pulverized product taken out from the lower outlet is more stable than before.

In addition, since the raw material with no fine powder adhered to the surface has a relatively large raw material friction angle at the time of pulverization, the pulverization efficiency does not decrease and an efficient operation can be performed. Problems are less likely to occur.

  Furthermore, according to the pulverization system of the present invention, even when a sieve-type classification device such as a vibrating sieve is used, clogging of the sieve is difficult to cause clogging, so that a stable classification effect can be maintained and operation is stabilized. .

Accordingly, in the present invention, the crushed sand particle size is stable even if the raw material moisture fluctuates by drying the crushed sand to a certain moisture by putting hot air into the vertical crusher.

  Furthermore, when using the electric power generation which supplies the electric power for driving the vertical crusher, if the gas heated using the exhaust heat of this generator is used as said hot gas, it will be efficient.

The details of the vertical crusher and the crushing system for producing crushed sand according to the present invention will be described below with reference to the drawings.
1 and 2 show a preferred example of an embodiment according to the present invention, FIG. 1 is a longitudinal sectional view of a vertical crusher, and FIG. 2 is a block diagram conceptually explaining the entire crushing system.

  The vertical crusher 1 used in the present embodiment is rotated by being driven by an electric motor through a casing that forms an outline of the vertical crusher 1 and a speed reducer 2B installed in the lower part as shown in FIG. The table 2 is provided with a plurality of crushing rollers 3 and the like disposed at positions that equally divide the outer peripheral portion of the rotating table upper surface 2A, which is the upper surface of the rotating table, in the circumferential direction. It is connected to a piston rod 9 of a hydraulic cylinder 8 via an upper arm 6 pivotally attached to a shaft 7 and a lower arm 6A formed integrally with the upper arm 6. By being actuated, it is pressed in the direction of the turntable upper surface 2A, and rotates by following the raw material through the turntable upper surface 2A.

A raw material charging port 35 and a raw material charging chute 13 for charging the raw material to the rotary table upper surface 2A are provided at the center upper portion of the rotating table upper surface 2A of the casing. It is configured so that it can be put into the table upper surface 2A (sometimes referred to as supply).
The charged raw material is rotated on the upper surface 2A of the rotary table, so that the rotary table upper surface 2A moves to the outer periphery while drawing a spiral trajectory, and is bitten by the rotary table upper surface 2A and the grinding roller 3 and pulverized. The

  Further, the raw material caught by the rotary table upper surface 2A and the pulverizing roller 3 passes over the dam ring 15 provided around the outer edge of the rotary table upper surface 2A, and the outer peripheral portion of the rotary table upper surface 2A and the casing To the annular passage 30 (which may be referred to as the annular space portion 30), which is a gap between the annular passage 30, falls below the annular passage 30, and is taken out of the vertical crusher 1 as a pulverized product from the lower outlet 34. It has become.

The casing is provided with a gas inlet 33 for introducing gas below the rotary table 2, and an upper outlet 39 for discharging the gas above the rotary table 2. During operation of the pulverizer 1, hot gas (air heated in the present embodiment) is introduced from the gas inlet 33, and an air flow of hot gas is generated in the casing from the lower side to the upper side of the rotary table. .
Therefore, the fine powder having a small diameter in the raw material that has passed over the dam ring is blown up, moves up in the casing, and is taken out as fine powder from the upper outlet 39.

Next, a preferred example of the overall configuration of the pulverization system using the vertical pulverizer 1 will be described with reference to FIG.
The pulverization system 100 used in the embodiment of the present invention includes a raw material hopper 42, a vertical pulverizer 1, a sieve classifier 20, a bag filter 46, a suction fan 45 (sometimes referred to as an exhaust fan 45), and a generator 81. , A dilution fan 55 (sometimes referred to as an exhaust fan 55), a distribution damper 58, and the like.
Note that the sieve classifier 20 includes a primary screen 20A, a secondary screen 20B, and a hopper 20C.

Here, as a raw material for the crushed sand, raw stones crushed to a certain size by a crusher such as a jaw crusher are stored in the raw material hopper 42 and connected by piping so that they can be fed into the vertical crusher 1 from the raw material inlet 35. Has been.
The raw material pulverized by the vertical pulverizer 1 is taken out as a pulverized product to the outside of the vertical pulverizer 1 from the lower outlet 34, and the extracted pulverized product is placed on the screen of the sieve classifier 20. It is the composition which is thrown into.

The sieving classifier 20 classifies the pulverized product charged twice by the primary screen 20A and the secondary screen 20B to produce a raw material having a large particle size that cannot pass through the primary screen 20A and the secondary screen 20B. It is configured such that it is fed into the vertical crusher 1 from the raw material charging port 35 via a conveying device such as a bucket elevator 41 and pulverized again.
The mesh size of the primary screen 20A and the secondary screen 20B is appropriately selected according to the desired particle size of the crushed sand.

  A distribution damper 58 is connected to the lower side of the sieve classifier 20, and a piping line is installed so that a pulverized product having a predetermined particle size can be charged again into the vertical crusher 1 by switching the opening of the distribution damper 58. In adjusting the particle size distribution of the crushed sand, the opening degree of the distribution damper 58 may be appropriately changed.

  In the present embodiment, the suction fan 45 sucks the air inside the vertical pulverizer 1 through the bag filter 46 to introduce the gas from the gas inlet 33, thereby A flow of airflow that flows upward is generated.

Here, in this embodiment, by connecting the exhaust heat gas line of the generator 81 to the gas inlet 33, the air is heated using the amount of heat generated in the generator 81 to obtain a hot gas. .
When the temperature of the gas sent from the exhaust heat line of the generator 81 is high, the temperature of the gas sent from the exhaust heat gas line is adjusted by the dilution fan 55.

  In the present invention, the heat sent from the exhaust heat line of the generator 81 is used as a preferred form, but the application of the present invention is not limited to this. For example, the generator is not used. In the case, the gas may be heated by separately preparing a heat source such as a hot air generating furnace.

The operation method of the crushing system 100 configured as described above according to the present embodiment will be described below.
The raw stone that is the raw material supplied from the raw material hopper 42 to the vertical crusher 1 is transferred from the raw material input port 35 provided at the center upper portion of the rotary table upper surface 2A of the vertical grinder 1 through the raw material input chute 13 to the rotary table. From the upper surface 2A, it is introduced into the center of the rotary table upper surface 2A.

  The charged raw material is rotated on the rotary table upper surface 2A, and when the centrifugal force is generated by the rotation, the rotary table upper surface 2A moves to the outer peripheral portion of the rotary table upper surface 2A while drawing a spiral trajectory, The rotary table upper surface 2A and the pulverizing roller 3 pressed against the rotary table upper surface 2A are caught and pulverized.

The raw material bitten by the rotary table upper surface 2A and the pulverizing roller 3 passes over the dam ring 15 and is discharged into the annular passage 30 between the outer peripheral surface of the rotary table 2A and the inner peripheral surface of the casing. The annular passage 30 falls and is taken out of the vertical crusher 1 from the lower outlet 34 as a pulverized product.
The raw material retained by the dam ring 15 and staying on the upper surface 2A of the rotary table is re-engaged with the upper surface 2A of the rotary table and the crushing roller 3 and is pulverized again.

  Here, during the operation of the vertical pulverizer 1, hot gas is introduced from the gas introduction port 33, and a gas flow is generated in the casing of the vertical pulverizer 1 from the lower side to the upper side of the rotary table 2. The fine powder having a small diameter is blown up in the raw material that has passed over the dam ring 15, rises in the casing, and is taken out as fine dust from the upper outlet 39.

  Here, in this embodiment, since the hot gas is introduced from the gas inlet 33 at the time of pulverization, the moisture adhering to the pulverized material is evaporated and reduced by the effect of the hot gas introduced from the gas inlet 33. Thus, the fine powder is difficult to adhere to the surface of the pulverized product. Accordingly, the pulverized product and the fine powder are separated, and the fine powder is quickly taken out from the upper outlet 39 together with the gas.

The pulverized product taken out of the vertical crusher 1 from the lower outlet 34 is put into the sieve classifier 20 and classified.
The raw material having a large particle size that cannot pass through the primary screen 20A and the secondary screen 20B in the sieving classifier 20 is again input to the vertical crusher 1 from the raw material input port 35 via the conveying device such as the bucket elevator 41. And pulverized again.
The pulverized product that has passed through the secondary screen becomes crushed sand.

  At that time, only a part of the pulverized product that passes through the primary screen but cannot pass through the secondary screen is returned to the vertical crusher 1 and pulverized again according to the type of raw material and the standard of crushed sand. The average particle diameter of the product can also be adjusted.

  According to the pulverization system 100 according to the present embodiment, even when a classification device such as the sieving classifier 20 is used, it is difficult to cause clogging of the sieve screen, so that a stable classification effect can be expected. Driving is stable.

  Moreover, since the grinding | pulverization system by this embodiment does not use the method of washing the ground material with water, the process of the dewatering cake used as industrial waste is unnecessary, and an installation is simple and efficient.

  Furthermore, it is efficient if a gas generator that supplies electric power for driving the vertical crusher is provided and the gas heated by using the exhaust heat of the generator is used as a hot gas.

Furthermore, the particle size distribution can be easily adjusted by changing the wind force of the suction fan 45.

  In this embodiment, the pulverization system 100 whose configuration is described in FIG. 2 is used as a preferable example. However, the pulverization system that can be applied to the present invention is not limited to this. It is within the scope of the present invention to appropriately change within a range that does not impair the functions necessary for the pulverization system, for example, the number of screens provided in the sieve classifier 20 may be one, or three or more, Needless to say, the bucket elevator 41 may be changed to a belt conveyor according to the arrangement.

Table 1 shows the results of investigating the influence of the sand particle size when the hot gas is introduced into the vertical crusher using raw materials with changed moisture content.
Rock used: Sandstone raw material produced in Yamaguchi Prefecture Size: -40mm
Vertical crusher: RS mill type 6 manufactured by Ube Industries Co., Ltd.

The raw material moisture 1.9% and 2.8% were adjusted by sun drying. 4.1% is based on raw material arrival, 5.3%, 6.4%, 7.1% is water that is artificially adjusted with water before testing. The test facility used heavy oil-fired hot air generator gas instead of generator exhaust gas.
The primary screen 20A (the screen mesh size is 5 mm in length and 5 mm in width) and the secondary screen 20B (the screen mesh size is 3 mm in length and 3 mm in width) were used.

Moreover, the dust ratio was calculated | required by following Numerical formula 1.

From the test results, it was confirmed that there were almost no fluctuations in the dust content and the crushed sand particle size up to the raw material moisture of 7.1%.

It is a longitudinal cross-sectional view which illustrates notionally the structure of the vertical crusher which concerns on embodiment of this invention. It is a flow sheet of a crushed sand apparatus using a vertical crusher according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vertical crusher 2 Rotary table 2A Rotary table upper surface 3 Crushing roller 20 Sieve type | mold classification apparatus 30 Annular passage 33 Gas inlet 34 Lower inlet 35 Raw material inlet 39 Upper inlet 41 Bucket elevator 42 Raw material hopper 45 Suction fan 46 Bug Filter 55 Dilution fan 58 Distribution damper 81 Generator 100 Grinding system

Claims (4)

A lower outlet and a gas inlet for taking out the pulverized product are provided below the rotary table, and an upper outlet is provided above the rotary table for discharging the gas.
While the raw stone put on the rotary table is pulverized between the rotary table and the pulverizing roller, a hot gas is introduced from the gas inlet, whereby the pulverized product blown up by the hot gas is removed from the upper outlet. A vertical crusher for producing crushed sand, which is taken out as fine powder from the slag and taken out by dropping the pulverized product that is not blown up by the hot gas to the lower outlet. A lower outlet and a gas inlet for taking out the pulverized product are provided below the rotary table, and an upper outlet is provided above the rotary table for discharging the gas.
While the raw stone put on the rotary table is pulverized between the rotary table and the pulverizing roller, a hot gas is introduced from the gas inlet, whereby the pulverized product blown up by the hot gas is removed from the upper outlet. A vertical pulverizer for producing crushed sand, which is taken out as fine powder and dropped by the hot gas and dropped to the lower outlet.
With a sieve classifier,
The pulverized product taken out from the lower outlet in the vertical pulverizer is classified by the sieve classifier, and the pulverized product having a predetermined particle size or less is taken out as crushed sand. A pulverization system for making crushed sand that is re-entered into a mold pulverizer and pulverized.   It is provided with the electricity generation which supplies the electric power for driving the vertical crusher, and the hot gas introduced from the gas inlet is gas heated using the exhaust heat of the generator The pulverizing system for producing crushed sand according to claim 2. The pulverization system for producing crushed sand according to claim 2 or 3, wherein a part of the crushed sand taken out from the sieve classifier is again put into a vertical grinder and pulverized.

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