JPH0775677B2 - Ultra fine grinding mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to an ultrafine grinding mill used for, for example, adjusting the particle size of a mixed slurry (CWM) of coal and water.

[Prior Art] A conventional outer cylinder rotary tube mill lifts an internal ball by a rotating force of an outer cylinder and crushes an object to be crushed such as coal by the impact of falling. Further, the conventional inner-cylinder rotary stirring mill rotates the peripheral speed at the stirring blade end of the inner cylinder shaft constantly regardless of the outer cylinder diameter, and is applied to small capacity machines.

[Problems to be solved by the invention]

The conventional outer cylinder rotary tube mill is used at a rotation speed of 1 or below the critical rotation speed ratio, and the fineness of coal is about 70-80% for 74μ or less, and the rotation speed is critical. If the number of revolutions is increased above the number of revolutions, the internal balls cling to the cylinder and rotate, causing a "swinging phenomenon" that prevents the balls from falling in the middle of the process, resulting in a sharp deterioration in pulverizability. Further, since the conventional inner cylinder rotary stirring mill keeps the peripheral speed of the stirring blade constant irrespective of the outer cylinder diameter, there is a problem in that the stirring force decreases and the performance deteriorates when the size increases.

[Means for solving problems]

The ultrafine pulverizing mill according to the present invention is intended to solve the above-mentioned problems, and a plurality of projecting stirring blades are provided on the inner peripheral surface of a cylindrical outer cylinder having both ends closed, An inner cylinder provided with a plurality of projecting stirring blades on the outer peripheral surface so as to intersect with the stirring blades of the outer cylinder is mounted coaxially with the outer cylinder, and either one of the outer cylinder and the inner cylinder is independently mounted. Alternatively, they are rotated in mutually opposite directions at a speed 1 to 3 times the critical speed, and 50 to 90% of a ball-shaped crushing auxiliary member is filled in the crushing chamber formed between the outer cylinder and the inner cylinder. It is characterized by

[Action]

That is, in order to apply a strong shearing force to the balls for assisting the crushing in the crushing chamber, the ultra-fine crushing mill according to the present invention is equipped with stirring blades in the inner and outer cylinders of the mill so that they can cross each other, and a moving blade and a stationary blade, respectively. And a crushing chamber formed between the outer cylinder and the inner cylinder while rotating either one of the outer cylinder and the inner cylinder independently or in mutually opposite directions at a high speed of 1 to 3 times the critical rotation speed. By filling the ball-shaped crushing assisting member with 50 to 90%, the ball-shaped crushing assisting member exerts a strong shearing force without causing a “swinging phenomenon”,
The pulverizing effect on an object to be pulverized such as coal can be enhanced and ultrafine particles can be obtained.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 and 2.
FIG. 1 is a front sectional view of a high-speed rotating ultra-fine grinding mill according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II in FIG. In the figure, reference numeral 1 is an outer cylinder having an agitating blade 15 on the inner peripheral surface thereof, a flange 20 is provided so as to be divided into upper and lower halves, and a manhole 11 is provided on the upper portion. Reference numeral 13 denotes an inner cylindrical shaft having an agitating blade 14 on its outer peripheral surface, and has a structure that can be driven by pulleys 25 and 26 via a motor and a V belt or chain (not shown). As shown in FIG. 1, the stirring blade 15 of the outer cylinder 1 and the stirring blade 14 of the inner cylinder shaft 13 are provided with a sufficient length so that they can overlap and cross each other when viewed from the axial direction, and are strong. It produces a large shear force. The outer cylinder 1 and the inner cylinder shaft 13 rotate independently or mutually reversely, and a strong shearing force is generated by stirring the slurry injected from the slurry injection hole 17 at high speed with a ball (not shown) filled in the crushing chamber 19. The finely pulverized slurry is passed through the eye plate 16, falls into the slurry discharge box 10, and is discharged from the slurry discharge hole 18 to the outside.

In this way, the stirring blades 14, 1 are attached to the outer cylinder 1 and the inner cylinder shaft 13, respectively.
Since 5 are equipped, one of them functions as a moving blade and the other of them functions as a stationary blade, so that the “swinging phenomenon” of the balls in the crushing chamber 19 is prevented, and the outer cylinder 1 and the inner cylinder shaft 13 are A strong shearing force is applied between the balls in the crushing chamber 19 by rotating them individually or mutually at a high speed of 1 to 3 times the critical rotation speed. For example, by filling the crushing chamber 19 with 50 to 90% of the balls. When a mixed slurry of coal and water (CWM) is injected, it is possible to atomize coal particles to 40% or less 100% and 1μ or less 15%.

〔The invention's effect〕

The ultrafine crushing mill according to the present invention is configured as described above, and since the ball-shaped crushing assisting member exerts a strong shearing force without causing a "swinging phenomenon", the crushed object such as coal is It is possible to obtain the effect that it becomes possible to make ultrafine particles into about 40% or less 100% and about 1μ or less 15%.

[Brief description of drawings]

FIG. 1 is a front sectional view of a high speed rotating ultrafine pulverizing mill according to an embodiment of the present invention, and FIG. 2 is a side sectional view thereof. 1 …… Outer cylinder, 13 …… Inner cylinder shaft, 14,15 …… Stirring blade, 19 ……
Grinding chamber, 25,26 …… Pulley.

Front Page Continuation (72) Inventor Tomiyasu 1-1 No. 1 Satinoura-cho, Nagasaki City, Nagasaki Prefecture, Nagasaki Research Institute, Mitsubishi Heavy Industries, Ltd. (56) Reference JP 61-8143 (JP, A) JP 62- 197162 (JP, A) JP-A-62-197163 (JP, A) JP-B-40-23754 (JP, Y1)

Claims (1)

[Claims] Claim: What is claimed is: 1. A cylindrical outer cylinder having a plurality of projecting stirring blades on its inner peripheral surface, the ends of which are closed, and a plurality of projecting stirring blades on the outer peripheral surface of the outer cylinder. An inner cylinder provided so as to be able to intersect with each other is mounted coaxially with the outer cylinder, and either one of the outer cylinder and the inner cylinder is rotated independently or in mutually opposite directions at a speed 1 to 3 times the critical rotation speed. An ultrafine grinding mill characterized in that the grinding chamber formed between the outer cylinder and the inner cylinder is filled with 50 to 90% of a ball-shaped grinding auxiliary member.