JPH03296449A - Method for grinding fibrous raw material or film raw material - Google Patents

Abstract

PURPOSE:To obtain a desired particle size by arranging a freely rotatable grinding roller on the upper surface of the outer peripheral part of a turntable and supplying a compressed and degassed fibrous raw material to the peripheral surface of the grinding roller. CONSTITUTION:A fibrous raw material subjected to degassing and compression molding is supplied to a grinder 1. The raw material supplied to the upper surface of the central part of a turntable 3 from a raw material charging chute 17 falls on the turntable 3 through a raw material supply pipe 50 to receive centrifugal force and draws a spiral locus on the turntable 3 to move to the outer periphery of the turntable 3 to be ground by a grinding roller 4. The finely ground raw material is blown up by the hot air rising from an annular space part 14 to rise and only a desired fine powder passes through a classifier 18 to be delivered to a succeeding dust collector from a discharge port 16a. By this method, grinding efficiency can be enhanced to a large extent.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The method of the present invention relates to a method for pulverizing fibrous raw materials or membranous raw materials by pulverizing them using a compression molding machine and a vertical pulverizer.

[Prior Art] Vertical pulverizers equipped with a rotary table and rollers are widely used as a type of pulverizer for finely pulverizing powders such as cement raw materials, coal, and chemicals. This type of crusher consists of a disk-shaped rotary table that is driven by a motor with a reducer to rotate at low speed in the lower part of a cylindrical casing, and a part that divides the outer circumference of the upper surface into equal parts in the circumferential direction, which is pressed by hydraulic pressure or the like. It is equipped with a plurality of rollers that are driven to rotate.

In this vertical crusher, powder as a raw material is supplied to the center of the rotary table through a supply pipe, and when the table rotates, the powder is subjected to centrifugal force in the radial direction of the table, and as it slides on the table, it is rotated by the table in the direction of rotation. It receives the force, slides between it and the table, and rotates somewhat slower than the table rotation speed.

The above two forces, that is, the forces in the radial direction and the force in the rotational direction are combined, and the powder moves to the outer periphery of the rotary table while drawing a spiral trajectory on the table. A roller is pressed into contact with this outer periphery and rotates, so the powder drawn in a spiral enters the space between the roller and the rotary table from a direction that forms an angle with the roller axis, and is crushed. do.

On the other hand, hot air is guided to the base of the casing by a duct, and this hot air is passed through a passage (in this specification, this passage is referred to as an annular space) between the outer peripheral surface of the rotary table and the inner peripheral surface of the casing. ), the fine powder rises inside the casing without being dried, and is discharged from the outlet as a mixture with hot air and sent to the next process.

By the way, if the material to be crushed supplied to the crusher is subjected to the crushing action by the crushing rollers only once, it will rarely be crushed to the fine powder particle size required by this crusher, and the center of the rotary table Not all of the fallen materials to be crushed are caught in the crushing rollers, so even if the powder particles that reach the outer edge of the rotary table rise up on the hot air current blown up from the annular space, they will not be able to be crushed by the crusher. By the time the particles reach the separator installed at the top of the table, depending on their particle size, they may fall or be classified and rejected by the separator and returned to the rotating table.

In this way, the material to be crushed, which is constantly fed into the crusher, rises from the rotary table to the separator or passes through the rotary table until it reaches the desired fine powder particle size to become the final product and flows out of the crusher. The particles are gradually pulverized into the desired particle size by repeating the falling process many times on the way to the separator.

[Problems to be solved by the invention] However, in the conventional vertical crusher as described above,
It is very suitable for heavy materials with relatively high specific gravity, such as cement raw materials, coal 2 limestone, dolomite, and other chemical products, and can be pulverized with high efficiency. However, it is difficult for fibrous materials such as wood chips and film materials such as rice husks, which have a specific gravity of less than 1, to be properly bitten by the above-mentioned crushing rollers and rotary table and to proceed with pulverization. The grinding time was long and the production capacity was low.

[Means for solving the problem] In order to solve the above problem, it is necessary to consolidate these raw materials with low bulk specific gravity to increase the specific gravity as much as possible and eliminate (deaeration) the air that exists between the raw materials. In the method of the present invention, after the fibrous raw material or membranous raw material is compressed and deaerated by a compression molding machine, a plurality of rotatable crushing rollers are arranged on the upper surface of the outer periphery of a rotary table, and the crushing rollers are subjected to a predetermined crushing process. It was decided to supply the material to the central part of the rotary table of a vertical crusher, which applies pressure and crushes the powder between the top surface of the rotary table and the circumferential surface of the crushing roller.

[Operation] The fibrous raw material or membranous raw material first enters the compression molding machine, becomes a pressed and consolidated mass, and is transported via a transporter to a supply chute installed at the center of the upper part of the vertical crusher. It is then fed to a vertical crusher. The above raw material, which has been degassed in the compression molding machine and has become a certain amount of lumps, falls onto the rotating table, traces a spiral trajectory on the rotating table, is once bitten by the crushing roller, and then moves to the outer periphery of the rotating table. The hot air overflows the rotary table and blows up from the annular space around the rotary table, and is blown up and air-transported to the classifier installed on the rotary table or at the top of the vertical crusher. While repeating this operation, the above-mentioned raw material is gradually pulverized into fine powder, and the raw material whose particle size is less than the desired size passes through a classifier and leaves the system, where it is recovered as a product by a solid-gas separator.

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

1 to 3 relate to an embodiment of the present invention, FIG. 1 is a general schematic diagram of an apparatus used in the method of the present invention, and FIG. 2 is a perspective view showing another embodiment of a compression molding machine. FIG. 3 is an overall longitudinal sectional view of the vertical crusher.

In FIG. 1, 100 is a raw material hopper, 200 is a compression molding machine, 300 is a transporter, and l is a vertical crusher. The compression molding machine 200 has a pair of left and right rolls 200a and 200b arranged facing each other. In contrast to the fixed roll 200a, the roll 200b is configured to be movable left and right by the operation of a hydraulic cylinder 202 so that the gap between the two can be arbitrarily changed.

Moreover, as another embodiment of the compression molding machine, an extrusion molding machine 200A shown in FIG. 2 can also be used.

This extrusion molding machine 200A sends the raw material inputted into a hopper 1oO downward via a rotary valve 110, and is housed in a barrel 210, and is driven by a plurality of screws 220 that are threaded in a spiral shape and rotate by meshing with each other. Extrusion die nozzle 25 at the end that moves horizontally and is compacted.
It presses and molds the consolidated raw material from scratch. Gas and moisture contained in the raw material generated during compaction by the screw 230 are discharged from the gas vent 240. 230 is a viewing window; 26
0 is a screw driving electric motor.

Since the raw material to be processed is wood (Japanese rice hulls), it is necessary to maintain the molded state after compaction, and therefore it is desirable to sprinkle moisture or an inexpensive binder such as water glass upon loading into the hopper 100.

On the other hand, to explain the vertical crusher 1, the crushing roller 4
are arranged at symmetrical positions with respect to the center of the rotary table 3 on the upper surface of the outer peripheral part of the rotary table 3 which is rotationally driven via the electric motor 2A and the reducer 2, and the crushing roller 4
is rotatably supported by a roller housing 5 via a roller shaft 4a, and the roller housing 5 is rotatable around a rotary bin 6 and is urged to press the crushing roller 4 against the rotary table 3 by a hydraulic cylinder (not shown).

On the other hand, above the center of the rotary table 3 is a discharge port 16a.
has been opened, and a final refined powder discharge pipe (not shown) is connected. Further, a raw material supply pipe 50 penetrates the ceiling wall of the upper casing 16 and is inserted into the crusher 1 from above the upper casing 16, and its lower end is connected to the separator 1.
8 and is arranged so as to reach near the top surface of the rotary table 3.

Regarding the kinematic behavior of the raw material granules supplied in this way on the rotary table, there are eight applications filed by the present applicant (
Patent Application No. 171015/1982, Patent Application No. 14329/1982
No. 7, Japanese Patent Application No. 59-52202, etc.).

It is obtained through kinematic analysis using parameters such as the falling position and the coefficient of friction between the falling object and the sliding surface.

On the other hand, below the outer periphery of the rotary table 3, there is an annular hot air passage 13 connected to a hot air generator by a duct.
An annular space 14 is defined above the hot air passage 13 between the rotary table 3 and the casing 15. In this annular space 14, a plurality of plate-shaped blades are arranged and fixed at equal intervals around the circumference while maintaining a required inclination angle with respect to the horizontal plane.

In addition, at the bottom of the hot air passage, there is a discharge chute 1 that temporarily discharges foreign objects during crushing and excess crushed materials in the event of overload.
9 is installed, and can be taken out from a discharge door 19b which is rotatable around a rotary bin 19a.

Next, the operation of the embodiment having such a configuration will be explained.

First, fibrous raw materials or membrane raw materials (hereinafter referred to as membrane raw materials) such as wood chips and rice husks are processed using a compression molding machine (roll compressor 200 or extrusion molding machine 20OA) as shown in Figures 1 and 2.
It is supplied via a hopper 100 to. Roll compressor 2
In the 00 and extrusion molding machine 200A, the membrane raw materials are discharged downward or laterally in a state in which the raw materials are strongly pressed together between the rolls 200a, 200b and the multi-axis screw 200 and integrally compacted. If the moisture content of the membrane raw material is particularly low, the raw materials will be deaerated even under strong pressure, but will not stick to each other, so in this case, pour the binder into the hopper in advance and pre-stir it. Good. As the binder, moisture or an inexpensive chemical agent such as water glass is used, and the binder is atomized and sprayed using a spray nozzle.

The membrane raw material, which has been deaerated and compacted as described above and has become a mass, is transferred to a conveyor 300 such as a belt conveyor.
It is laterally transferred and supplied to the vertical crusher 1.

The raw material supplied from the raw material input chute 17 to the upper surface of the central part of the rotary table 3 falls onto the rotary table 3 via the raw material supply pipe 50, and draws a spiral trajectory on the rotary table 3 due to centrifugal force. The powder is then moved to the outer circumferential side of the rotary table, and is crushed by the crushing roller 4.

The raw material that has been crushed into fine powder by the crushing roller 4 is blown up by the hot air rising from the annular space 14, and only the desired fine powder passes through the classifier 18 and exits from the discharge port 16a to a dust collector installed later. and delivered to a device (not shown).

In the present invention, the membrane raw material with low specific gravity is compacted and deaerated using a compression molding machine, and a certain amount of lumps (approximately 20 to 50
mm) and then pulverized in a vertical pulverizer, it is easily caught in the pulverizing part formed by the rotary table and the pulverizing rollers, resulting in a good pulverized state and significantly improved pulverizing efficiency. According to an experiment using a test machine, when comparing pulverization using only a vertical pulverizer and pulverization using a vertical pulverizer after pre-consolidation according to the present invention, it was found that although the same fineness was obtained, the former was 3kg/hr
On the other hand, the latter achieved a processing capacity of 8 kg/hr. Moreover, the vibration value in the former operating state (half amplitude 90~
120μ) showed a much larger value than the latter vibration value (half amplitude 40 to 60μ). From these phenomena,
In particular, when pulverizing substances with low specific gravity as they are, the air layer interposed between the raw materials worsens the pulverization condition, and therefore the amount of raw material filling the vertical pulverizer is large, which causes an imbalance with the blowing air. It is presumed that the violent movement up and down inside the crusher will result in increased vibration. Therefore, the method of the present invention is intended to improve the crushing capacity and reduce vibration by performing the crushing step after eliminating as much as possible the air layer interposed between the raw materials by compaction deaeration.

[Effects of the Invention] As is clear from the above description, in the pulverization method of the present invention, the fibrous or membranous raw material is sequentially pulverized in a decompressed and airtight shape using a compression molding machine and a vertical pulverizer. In addition, the crushing efficiency is greatly improved by 2 to 3 times, and the vibration value generated by the crusher is also relatively small, allowing quiet and stable operation.

[Brief explanation of drawings]

FIG. 1 is an overall schematic diagram of an apparatus used in the method of the present invention, FIG. 2 is a perspective view showing another embodiment of a compression molding machine, and FIG. 3 is an overall vertical sectional view of a vertical crusher. 1... Vertical crusher, 2A... Electric motor, 3
... Rotating table, 4 ... Grinding roller, 50 ... Raw material supply pipe, 100 ...
Hopper, 200... Compression molding machine, 200a, 200b... Roll, 200A... Extrusion molding machine, 210... Barrel, 220... Screw, 240...・・・・・・
Gas vent, 250...Extrusion die nozzle,
300... Transport aircraft. Figure 1

Claims (1)

[Claims] (1) After the fibrous raw material or membranous raw material is compressed and deaerated by a compression molding machine, a plurality of rotatable crushing rollers are arranged on the upper surface of the outer periphery of a rotary table, and the crushing rollers are rotated by applying a predetermined crushing pressure. A method for pulverizing fibrous or membranous raw materials, which is supplied to the center of a rotary table of a vertical pulverizer to be pulverized between the top surface of the table and the peripheral surface of the pulverizing roller.