JPS6245351A - Scraper for discharging foreign matter of vertical mill - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a scraper for removing foreign matter one by one from a vertical mill, and particularly relates to an improvement in the shape of the scraper.

[Conventional technology] Vertical mills are often used to crush coal, coke, etc.
As shown in FIG. 3, the material to be crushed, which is supplied from the supply pipe 1 and falls onto the center of the crushing table 3 at the lower end of the throat flanges 2, is decelerated in 4 ways by the drive of a motor (not shown). By rotating the grinding table 3 through the
It moves in the outer circumferential direction due to centrifugal force and is caught between the crushing cola 5 and the crushing track 3a on the crushing table 3 to crush it.

The pulverized material is sucked into the wind tunnel 8 through the air supply duct 7 provided in the lower casing 6 by a fan (not shown), passes through the nozzle ring 9, and is carried by the airflow to the upper end of the upper casing 10. Hopper 2 of classifier 11
The powder is guided into the hopper 2 and classified into coarse powder and fine powder by the separating blade 12 in the hopper 2, and the coarse powder descends along the inner wall of the hopper 2, falls from the drop opening onto the grinding table 3, and is re-pulverized. Ru. On the other hand, the fine powder is discharged as a product from the discharge port 13 along with the exhaust air, and is air-transported to the Reicron through a duct (not shown), where it is collected.

In such a vertical mill, in order to carry unpulverized foreign matter such as small pieces of iron that have fallen into the wind tunnel 8 without being blown up by the airflow flowing from the nozzle ring 9, and objects to be crushed with a heavy specific gravity to the foreign matter discharge port 14, As shown in Fig. 4, the lower casing 6
A scraper 15 is supported and fixed to the outer periphery of the lower surface of the crushing table 3 in the wind tunnel 8 .

[Problems to be Solved by the Invention] By the way, since the scraper 15 in the wind tunnel 8 of the vertical mill was installed straight in the radial direction of the crushing table 3 as shown in FIG. Since a force is generated against the opening that pushes foreign matter that is not crushed into the air supply duct 1-F, foreign matter accumulates inside the air supply duct 7, and the effective cross-sectional area of the air supply duct 1-7 decreases. As a result, the pressure In increases, and the air supply duct 7 is blocked, resulting in an inoperable situation.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a scraper for discharging foreign matter that prevents unpulverized foreign matter from escaping from the tip of the scraper during operation of a vertical mill.

[Means for Solving the Problems] In order to solve the above-mentioned problems, a scraper for discharging foreign matter in a vertical mill according to the present invention is provided by bending the tip side of the scraper provided in the lower casing wind tunnel in the rotation direction of the grinding table. The scraper is characterized by having a hook bent in the direction of rotation of the grinding table at the tip of the scraper.

[Example] An embodiment of the vertical mill ornament tJI outlet scraper according to the present invention will be described with reference to FIG. A duct, 8, is installed inside the lower casing 6.
f 1fi1. A foreign matter JJI outlet 14 is bored in the bottom plate of the wind tunnel 8, and a foreign matter discharge scraper 15' is provided inside the wind tunnel 8. This scraper 1 for removing foreign matter
5' is a scraper 15 for discharging foreign matter, which is supported and fixed to the outer periphery of the lower surface of the crushing table 3 and located at the bottom of the wind tunnel 8.
The tip side of ' is bent in the direction of rotation of the crushing table 3. In addition, 9 is a nozzle ring.

FIG. 2 shows another embodiment of the scraper for removing foreign matter in a vertical mill according to the present invention.
'' is supported and fixed on the outer periphery of the lower surface of the crushing table 3, and the pressure 1
Within the hook 18, a hook portion 16 is disposed straight on the outside in the radial direction of the grinding table 3, and a hook portion 16 bent in the rotational direction of the grinding table 3 is formed at the tip thereof.

As described above, the scraper 15' for discharging foreign matter according to the present invention has its tip side bent in the rotational direction of the crushing table 3,
Further, the scraper 15'' for removing foreign matter has a hook portion 16 bent in the rotational direction of the crushing table 3 at its tip, so that when the vertical mill is operated, the scraper 15'' is inserted into the wind tunnel 8 from the air supply duct 7 by a fan (not shown). Foreign objects that are not crushed, such as small pieces of iron that are introduced by suction and fall into the wind tunnel 8 without being blown up by the airflow passing through the nozzle ring 9 and objects to be crushed with a heavy specific gravity, are foreign objects that rotate together with the crushing table 3. The foreign matter does not escape from the tips of the discharge scrapers 15' and 15'', but is scraped into the foreign matter discharge scrapers 15' and 15'' and carried to the foreign matter discharge port 14, from where it is discharged and dropped.

In each of the above embodiments, the scraper for removing foreign matter '5'
, 15 rt is provided only one each,
Two or three sheets may be provided.

[Effect of selling] As can be seen from the above explanation, foreign matter T)F in the vertical mill of the present invention
The dispensing scraper has a tip bent in the direction of rotation of the grinding table, or a hook bent in the direction of the rotating blade of the grinding table. The unpulverized foreign matter that has fallen into the wind tunnel does not escape from the tip of the foreign matter discharge scraper, is scraped by the foreign matter discharge scraper, is carried to the foreign matter discharge port, and is discharged and dropped from there. Therefore, since unpulverized foreign matter is not pushed into the air supply duct, the effective cross-sectional area of the air supply duct 1 does not decrease.
There is no blockage of the air supply duct 1, and the amount of air supplied to the mill body can be stabilized.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 shows an embodiment of the scraper for removing foreign matter in a vertical mill according to the present invention, and Fig. 2 is a schematic 4M cross-sectional plan view of the wind tunnel in the lower casing, and Fig. 2 shows another embodiment of the scraper for discharging foreign matter in a vertical mill according to the present invention. Examples are shown. Figure 3 is a vertical sectional view of a vertical mill, Figure 4 is a conventional 5' scraper for scraping, and Figure 3 is a cross-sectional view of the wind tunnel inside the lower casing. FIG. 3 is a cross-sectional view taken along line 8-Δ in FIG. 3; 3...Crushing table 6...Lower casing 8
...Wind tunnel +5', 15''...Scraper 16 for removing foreign matter
...Applicant: Kawasaki Heavy Industries, Ltd. Figure 1 Figure 3

Claims (1)

[Claims] The tip of the scraper provided in the wind tunnel in the lower casing of the vertical mill is bent in the rotational direction of the grinding table, or the tip of the scraper is provided with a hook bent in the rotational direction of the grinding table. A scraper for removing foreign matter from a vertical mill.