JPS6320047A - Method and device for crushing raw material lump - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method and apparatus for pulverizing raw material lumps such as tarinka and gypsum to produce cement.

<Prior art and its problems> Cement is manufactured by mixing gypsum with tarinka, which has been rapidly cooled after firing, and pulverizing the mixture. Tarinka is 80mm sieve residue 20
This is roughly crushed with a hammer crusher etc. to about 20% of the remaining 30 mm, and after mixing about 5% of gypsum, it is crushed. Conventionally, ball mills have been used in most cases as crushers. A flow sheet of a grinding system using a ball mill is shown in Figure 2.

In FIG. 2, 1 is a hopper consisting of 1a and 1b for storing raw material lumps such as tarinka and gypsum. 2 is a ball mill. As shown in the figure, the ball mill 2 is a machine in which a large number of steel balls are placed inside a cylinder that rotates with the axis of rotation approximately horizontal, and the steel balls rotate as the cylinder rotates to perform pulverization.
Normally, there is a 1st to 2a which is filled with steel balls of various diameters from 40am to 9h+m and performs coarse crushing, and a 2nd to 2b which is packed with several types of steel balls from 17rQIIl to 40+yun and which performs fine crushing. are doing. 3 is a transporter, and 4 is a classifier. There are various types of classifiers 4, but most of them usually classify fine powder and coarse particles by rotating classification blades inside a casing. The action will be explained below. The tarinka coarsely crushed to a particle size with about 20% of the residue on the 30mm sieve is sent to hopper 1a.
, gypsum is stored in the hopper 1b. The raw material lumps of talin and gypsum stored in the hopper 1 are sent to the ball mill 2 by a conveyor 7. The raw material lump is pulverized by a ball mill and discharged as powder, and sent to a classifier 4 by a transporter 3. The fine powder classified by the classifier is discharged from the system as a product, and the coarse particles are sent to the ball mill again and pulverized.

In such a crushing system, the quality of the cement product is good, but there is a problem that the power required for crushing is too large and the power consumption per product is poor.

The crushing system shown in Figure 3 has been put into practical use as a method to improve the electricity consumption rate (West German KHD Humb.
olt Wedag AG). In this method, raw material lumps are crushed by a roll press 5 and then supplied to a ball mill 2. Part of the load of the ball mill 2 is taken over by a roller press 5, which reduces the electrical energy consumption of the entire system. The aim is to reduce this.

As shown in FIG. 4, the roll press has a pair of rolls 5a.
, 5b, the raw material mass is supplied to the biting side, and the raw material mass is crushed by the pressing force.

In this pulverization method, as shown in FIG. 3, raw material lumps stored in a hopper 1 are supplied to a roll press 5 by a conveyor 7.
The powder crushed by the roll press 5 is transferred to a classifier 4 by a transporter 3 and classified into fine powder and coarse particles. Fine powder is discharged outside the system as a product, and coarse particles are sent to a ball mill 2 and pulverized. The powder crushed by the ball mill 2 is sent to the classification R4 by the transporter 3 together with the powder crushed by the iI flat roll press 5 and classified into fine powder and coarse particles, and the coarse particles are sent to the ball mill 2. Returned and crushed.

According to the above solid grinding method, the electric power consumption is improved by 10 to 20% compared to the conventional grinding method using only a ball mill, and the product quality remains unchanged.

However, it cannot be said that this method is sufficient to reduce the electricity consumption rate. In other words, in a roll press, crushing is performed in a short time when the raw material mass passes through the roll nip, and the residence time is short, so
This is because the particle size of the obtained granular material is at most 2 mm, and the sieve residue is about 20%, and the reduction in the load on the ball mill is not sufficient.

Grinding power consumption! ! The fifth method is the one with the least amount of 1ffl.
There is a method using a vertical roller mill 6 as shown in the figure.

The structure of the vertical roller mill 6 will be explained below.

Reference numeral 11 designates a circular rotary table having an annular groove 11a having a concentric rotation center near the outer periphery of the upper surface, and is connected to rest on a reduction rock 17 and driven by a motor 18. 1
The row arms 2 are rotatably supported on a swingable arm 12a, and are pressed against the groove 11a by a hydraulic cylinder 12b and rotated in contact with each other.The row arms are usually provided at two to four equal positions of the groove 11a. Reference numeral 13 denotes a classifier which is provided above the table 11 concentrically with the table and has a substantially inverted conical outer shape, and has a fixed guide blade 13a on the outer periphery of the upper part and a rotating blade 13b inside.
is provided. 14 is a casing that accommodates a table, rollers, classifier, etc. 15 is a raw material chute.

The outlet 13c of the classifier 13 is connected to a collector 61 such as a bag filter.
It is connected to the exhaust blower 62 via.

The raw material mass from the hopper 1 passes through an airtight feeder 21, passes through the raw material chute 15, is supplied to the center of the table 11, and is crushed by the rollers 12 while flowing outward due to centrifugal force.

On the other hand, air enters from the inlet 19 and rises inside the casing 14 through a nozzle portion 20 formed between the outer periphery of the table 11 and the inner surface of the casing 14. The raw material crushed on the table 11 flows outward due to centrifugal force, rises inside the casing 14 together with the gas flow passing through the nozzle part 20, passes through the fixed blades 13a at the top of the classifier, becomes a swirling flow, and then flows through the rotating blades. 13b, the rotation is strengthened and classification is performed.

The fine powder is discharged to the outside from the outlet 13c along with air and collected by the collector 61 to become a product, while the coarse particles fall along the conical peripheral wall of the classifier, are returned to the table 11, and are crushed again. Ru.

Furthermore, coarse particles that are not blown up by the nozzle section 20 are scraped up by a scraper 22 and returned to the hopper 1 by a transport rack 3.

The method of crushing raw material lumps using such a vertical roller mill has the advantage that the crushing power is smaller than the crushing method using a ball mill, and the power consumption is approximately half, but on the other hand, it makes the particle size distribution of cement the same as the crushing method using a ball mill. It is difficult to ensure the same strength (according to ``Physical Test Method for Cement JJIS R5201'') when concrete is made.

In addition, when a vertical roller mill crushes raw material lumps, powder and granules are mixed with the raw material lumps, so self-supporting vibrations due to a slipping phenomenon tend to occur at the biting part, making stable operation difficult.

<Object of the Invention> The present invention has been devised in view of the above-mentioned problems, and the raw material lump is crushed with a vertical roller crusher and then crushed with a ball mill, thereby reducing the crushing power and improving the product quality. It is an object of the present invention to provide a method and apparatus for crushing raw material lumps, which is almost equivalent to a crushing method using a chisel, and which allows stable operation.

Means for Solving the Problems In order to achieve the above object, the method for crushing raw material lumps according to the first invention of the present application includes a rotating double in a casing, and a raw material lump that is pressed against the outer periphery of the top surface of the table to crush the raw material lumps. A raw material lump is supplied to a vertical roller crusher equipped with a plurality of rollers and crushed to the required particle size, and the powder and granules are classified into fine powder and coarse particles by a classifier. The grains are refined using a ball mill in which a large number of steel balls or cylindrical pebbles are packed into a rotating cylinder with its axis of rotation substantially horizontal.

Further, the raw material lump crushing apparatus of the second invention of the present application includes a vertical roller crusher equipped with a rotary table in a casing and a plurality of rollers that are pressed against the upper surface of the table near the outer periphery to crush the raw material lump, and a vertical roller crusher. There is a classifier that receives the powder crushed by the crusher and classifies it into fine powder and coarse particles, and a large number of steel balls or cylindrical pebbles are packed into a cylinder that rotates with the axis of rotation approximately horizontal. and a ball mill for receiving and refining coarse particles.

<Function> The raw material lump is crushed by a vertical roller crusher to a particle size of 1 mm with a sieve residue of 20% or less. The residence time of the vertical roller crusher in the crushing zone is longer than that of a roll press, and the particle size of the powder can be adjusted by undergoing crushing action many times between the table and rollers, and by adjusting the rolling blade of the roller. Therefore, it is easy to reduce the particle size of the obtained powder to about 20% or less of 11111 sieve residue. The powder obtained by the vertical roller crusher is classified into fine powder of 88 microns or less and coarse particles larger than 88 microns using a classifier.The fine powder is discharged from the system as a product, and the coarse particles are refined using a ball mill. be done. Unlike conventional ball mills, it has only one chamber and has a structure in which a large number of steel balls of various diameters from 17+nn to 40+++m are packed inside a cylindrical body that rotates with the axis of rotation almost horizontally. Refining is performed by the impact effect when the steel balls are entangled and fall, and the crushing effect when they rotate in contact with each other.

In this way, the coarse crushing of the ball mill's crushing action is taken over by the vertical roller crusher, and the ball mill only performs fine crushing, so the power consumption of the crushing system as a whole is significantly reduced. Since this process is carried out using a ball mill, the product quality is comparable to that obtained using only a ball mill.

<Examples> Examples of the present invention will be described below with reference to the drawings.

FIG. 1 shows a flow sheet of a first embodiment of a crushing apparatus for carrying out the method of crushing raw material lumps of the present invention.

In FIG. 1, 1 is a hopper consisting of 18 and 1b. 3 is a transporter, and 4 is a classifier. 30 is a vertical roller crusher, and 31 is a ball mill.

The vertical roller crusher 30 has a structure similar to that of the vertical roller mill 6 described above from which the classifier 13 is removed, and will be described below.

Reference numeral 41 designates a circular rotary table having an annular groove whose rotation center is concentric near the outer periphery of the upper surface, and is connected to ride on a reduction gear 47 and driven by a motor 48 . The rollers 42 are rotatably supported on a swingable arm and rotated in contact with the table 41 by being pressed against the table 41 by a hydraulic cylinder, and usually two to four rollers are provided. 44 is a casing that accommodates a table, rollers, etc. 45 is a scraper,
46 is a powder chute, and 49 is a raw material lump chute.

The classifier 4 is a rotary type, and the supplied powder and granules are blown up by the action of an impeller 4a, but the coarse particles are thrown out in the radial direction by centrifugal force due to the action of the impeller and fall along the inner casing 4b. , the fine powder is discharged outside from the coarse particle outlet 4C that penetrates the outer casing, passes through the impeller without being affected by the impeller, falls along the outer casing 4d, and enters the fine powder outlet 4e at the lower end. is discharged to the outside. ball mill 3
1 performs only fine crushing, so there is no first seedling for coarse crushing as in the conventional case, and it consists only of small diameter steel balls (steel balls of several diameters from 17rRm to 40IRIII).

The ball mill 31 has a rotating body that rotates with its axis of rotation substantially horizontal, and is filled with steel balls having an apparent volume of 1/3 to 1/4 of the internal volume of the cylindrical body.

Next, the action will be explained.

The raw material lump in the hopper 1 is not crushed by a hammer crusher or the like, and is a lump of about 80 nu++ with 20% remaining on the sieve.

The raw material lumps are transported by the conveyor 7, pass through the chute 49, and are placed in the vertical roller sifter 1 and 30 to form 111Ill sieve residues 20
% or less falls from the outer periphery of the table 41, is scraped up by a scraper 45, and is discharged to the outside through a powder chute 46. The powder from the vertical roller crusher 30 is lifted by a mechanical transport device 3 such as a packet elevator and supplied to a classifier 4 through a chute. A classifier classifies the powder into fine powder of 88μ or less and coarse particles larger than that, the fine powder is discharged outside as a product, and the coarse particles are supplied to a ball mill 31 and refined. If the powder refined by the ball mill can be used as a product, it can be taken out as a product as shown by arrow 32, but if coarse particles remain and there is a problem as a product, it can be taken out by a transport machine as shown by arrow 33. 3, it is sent to a classifier 4 to separate coarse particles.

FIG. 6 shows a flow sheet of a second embodiment of the raw material lump crushing apparatus of the present invention.

This embodiment differs from the first embodiment described above in that the powder from the vertical roller crusher 30 is transported by air flow rather than by the mechanical transport device 3.

The raw material mass passes through an airtight feeder 21 to a vertical roller crusher 3
0 and crushed. The vertical roller crusher 30 is sucked from the top and has a negative pressure, and air flows in from the air inlet 51. The inflowing air flows through a nozzle ring 5o formed around the table 41.
The air is blown up by the air flow and flows out from the top 52.

The powder and granules flowing out of the vertical roller crusher 30 in an air flow pass through a duct 63 and flow into a cyclone-type pre-classifier 60, where they are classified into an air flow containing fine powder and powder and granules. The air flow containing powder flows out from the upper part of the pre-classifier 60, and the powder and granular material flows out from the lower part. The air flow containing fine powder passes through a duct 65 to a dust collector 61 such as a bag filter.
The fine powder is separated into air and the air is sucked by the exhaust blower 62 and discharged to the outside, and the fine powder is discharged to the outside as a product. The granular material that is classified by the pre-classifier 60 and discharged from the bottom is sent to the rotary classifier 4, where it is classified into coarse particles and fine particles. The fine powder is discharged to the outside as a product together with the fine powder obtained by the above-mentioned π collector, and the coarse particles are sent to the ball mill 31 and refined. The powder obtained by the ball mill 31 may be used as a product as it is as shown by the arrow 32, or may be sent to the classifier 4 by the transporter 3 as shown by the arrow 33. Note that the air flowing inside the ball mill 31 is also passed through a duct 64 to a pre-classifier 601. : Guided.

This embodiment has the advantage that the temperature rise in the vertical roller crusher 30 is small because the heat generated during coarse crushing by the vertical roller crusher v30 is removed by air flow.

FIG. 7 shows a flow sheet of a third embodiment of the raw material lump crushing apparatus of the present invention. The difference between the third embodiment and the second embodiment described above is that the classifier is a coarse classifier 6 shown in FIG.
6 is used.

The coarse classifier 66 has an outer cone 66 as shown in FIG.
It has a structure in which an inner cone 66c is arranged concentrically inside b, and an air outlet 66e containing refined powder is provided at the center of the ceiling of the inner cone 613c, and d3 is provided with an air outlet 66e containing fine powder at the center of the bottom of the outer cone. A coarse particle outlet 66h is provided to surround the air population 66a and the air inlet 66a. An angle-adjustable wind direction adjustment vane 66dtfi is provided on the outer periphery of the upper end of the inner cone 66c. At the lower end of the air outlet 66e containing fine powder, short cylindrical bodies 66i having different diameters are arranged concentrically, and the surface connecting the lower ends of each cylindrical body forms an inverted conical shape. It is shaped like this.

The air containing the powder passes through the inlet 66a and is blown up through the gap between the outer cone 66b and the inner cone 66C. and the inner cone 66 from the wind direction adjustment vane 66d.
c and collides with the outer surface of the air outlet 66e. Due to the collision, the coarse particles lose kinetic energy and fall, and the fine powder is discharged to the outside from the air outlet 66e along with the air.

The coarse particles pass through the gap 66f at the bottom of the inner cone 66c, fall within the outer cone 66d, and are discharged to the outside from the coarse particle outlet 66h at the bottom of the outer cone 66b. Incidentally, while the coarse particles fall within the outer cone 66b, the accompanying fine powder is removed by the air flow blown up.

As shown in FIG. 7, the powder coarsely crushed by the vertical roller crusher 1-30 and the powder refined by the ball mill 31 are blown up by the air flow and enter the coarse particle classifier 66. The coarse particle classifier 66 classifies the air stream containing fine powder into coarse particles, the fine powder is collected by the dust collector 61 and discharged outside as a product, and the coarse particles are sent to the ball mill 31 and refined. Circulate as powder.

FIG. 9 shows a flow sheet of a fourth embodiment of the present invention. In this embodiment, a circulation fan 67 is added to the crushing device of the third embodiment, and the circulation fan 67 circulates the air necessary for transporting the powder and granules, and blows hot air into the inlet of the vertical roller crusher. This allows raw material lumps to be crushed while drying.

<Effects of the Invention> As described above, the raw material lump crushing method of the first invention and the raw material lump crushing apparatus of the second invention of the present application have the following effects.

(1) Since the coarse crushing function of the ball mill is taken over by a vertical roller crusher, the power consumption of the ball mill is significantly reduced.

- Since the vertical roller crusher 17 can process even large pieces of tarinka, a crusher such as a hammer crusher is not required, which reduces equipment costs and power consumption.

■ Even after subtracting the reduction in power consumption of the ball mill and the increase in power consumption of the vertical roller crusher due to the omission of the hammer crusher, the overall crushing system has a power consumption rate that is 30 to 40% lower than that of a ball mill alone. reduction is achieved.

(Compared to vertical roller mills, the 4-vertical roller crusher does not coexist powder and raw material lumps during crushing, so there is no self-excited vibration due to sliding phenomenon, and stable operation is possible.

6) Since the refining is performed using a ball mill, the product quality is the same as when the refining is performed using a ball mill alone.

[Brief explanation of the drawing]

Fig. 1 is a flow sheet of a crushing device for raw material lumps according to the first embodiment of the present invention, Fig. 2 is a flow sheet of a grinding system using only a conventional ball mill, and Fig. 3 is a flow sheet of a crushing system using only a conventional ball mill. Flow sheet of a crushing system, FIG. 4 is a conceptual diagram of a roll press, FIG. 5 is a flow sheet of a crushing system using a vertical roller mill, FIG. 6 is a flow sheet of the second embodiment of the present invention, FIG. 7 8 is a sectional view of a coarse particle classifier, and FIG. 9 is a flow sheet of a fourth embodiment of the present invention. 4... Classifier 30... Vertical roller crusher 31...
・Ball mill 41...Rotary table 42...Roller 44...Casing Fig. 1 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8

Claims (3)

[Claims] (1) A raw material lump is supplied to a vertical roller crusher equipped with a rotary table and a plurality of rollers pressed against the upper surface of the table near the outer periphery of the table to crush the raw material lump, and the raw material lump is crushed to the desired particle size. The above powder and granules are classified into fine powder and coarse particles using a classifier, the fine powder is used as a product, and the coarse particles are packed with a large number of steel balls or cylindrical pebbles in a cylinder that rotates with the axis of rotation approximately horizontal. A method for pulverizing raw material lumps, which is characterized by pulverizing them in a ball mill. (2) A vertical roller crusher equipped with a rotary table in a casing and a plurality of rollers that are pressed against the vicinity of the outer periphery of the top surface of the table to crush raw material lumps, and a vertical roller crusher that receives the powder crushed by the vertical roller crusher. There is a classifier that separates fine powder and coarse particles, and a ball mill that rotates with its axis of rotation approximately horizontally, in which a large number of steel balls or cylindrical pebbles are packed, and that receives and refines the coarse particles from the classifier. A raw material lump crushing device characterized by comprising: (3) A duct that guides the powder crushed in the vertical roller crusher and blown up by the air flow to a classifier, and a duct that receives the air flow containing the fine powder classified by the classifier and collects the fine powder. The apparatus for crushing raw material lumps according to claim 2, further comprising a dust collector.