JP3369491B2 - Vertical roller mill - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical roller mill in which an object to be crushed is crushed by being bitten between a rotary table and a crushing roller, and the crushed material is discharged by an upward air flow.

[0002]

2. Description of the Related Art A vertical roller mill will be described with reference to FIG. 1 showing an embodiment of the present invention. A rotary table 3 rotating in a casing 2 is provided with a plurality of rotatable crushing rollers 4. Is a device for crushing the supplied object to be crushed by both 3 and 4. In this vertical roller mill 1, ascending airflow a from the air intake 7 provided in the casing 2 below the rotary table 3 by sucking air from the upper portion of the casing 2.
There is a device that takes in the powder and guides the pulverized product to the outside of the casing 2 along with the ascending airflow a. In this product, the fine powder is collected as a product by the classifier 12 on the upper part of the casing 2, and the coarse powder is again transferred to the rotary table 3. It is returned and crushed.

As an example of a conventional vertical roller mill of this type, there is JP-A-4-256449 (publication 1). In this product, at least one guide vane is arranged inside the intake of the hot gas duct so as to be rotatable about a vertical axis, and the guide vanes are used to rectify the introduced gas in the rotating direction of the rotary table to generate pressure. Loss is reduced and the upstream airflow a is evenly distributed around the outer circumference of the rotary table 3.
Is to occur.

Further, as another conventional technique, an actual flat blade 4-9
The thing described in the 8443 gazette (publication 2) can be mentioned. This product has a branch chute with a damper connected to the coarse powder discharge port, and during abnormal stop such as power failure, the coarse chute that is trying to stay inside the classifier is discharged from the branch chute to the outside and restarted. Coarse powder is not mixed in the product.

[0005]

In such a vertical roller mill 1, when an abnormal stop such as a power failure occurs during operation, the ascending airflow a disappears. Therefore, the ascending airflow a rises inside the mill 1. Air intake 7
There is a high possibility that it will leak out. If the pulverized material leaks out, it may cause a problem in the working environment or affect the human body.

The technique described in Publication 1 can prevent the leakage of the pulverized material from the air intake 7 due to the presence of the guide vane, as compared with the case where the vane is not provided. It cannot effectively prevent things from leaking out.

In the technique described in the publication 2, the branch chute is for avoiding the retention of the inside of the mill, and even if the crushed product can be discharged to the outside of the mill by the branch chute, the air intake 7 is opened. If so, the pulverized product will still leak out, and the damper is also in the branch chute, so the air intake 7 cannot be opened and closed, and leakage from the air intake 7 cannot be prevented.

It is an object of the present invention to prevent crushed substances rising inside the mill along with the rising airflow from leaking out of the mill when the rising airflow of the vertical roller mill disappears. .

[0009]

In order to achieve the above object, the present invention is designed to close the air intake when the updraft disappears. When the air intake is closed, the crushed substances rising inside the mill will not leak out. When the ascending air flow disappears, it means that when the exhaust fan stops and intake air is exhausted, the raw material is supplied too much in the mill, the mill pressure loss increases, and the air volume (intake volume) of the exhaust fan decreases. is there.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION According to an embodiment of the present invention, a crushing roller is rotatably pressed against a rotary table in a casing with a crushed object interposed between the rotary table and the crushing roller. In a vertical roller mill that crushes and takes in an ascending airflow from an air intake provided in the casing below the rotary table by sucking air from the upper part of the casing and guides a crushed product to the outside of the casing along with the ascending airflow, A configuration may be adopted in which a gravity damper is attached to the air intake, the gravity damper is rotated and opened by the upward airflow, and is closed by its own weight when the upward airflow disappears to close the air intake. .

According to this structure, since the damper is a gravity damper, the damper closes the air intake port by its own weight without power even in the case of a power failure, so that the crushed material inside the mill is surely prevented from leaking. .

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment is shown in FIGS. 1 to 3, in which 1 is a vertical roller mill, in which a rotary table 3 and a plurality of rotatable crushing rollers 4 are provided in a casing 2.
The crushing roller 4 faces the upper surface of the outer peripheral edge of the rotary table 3. The crushing roller 4 is supported by a trunnion 15, and its arm portion 14 is pressed by the pressure cylinder 5, and this pressing causes the crushing roller 4 to rotate via the trunnion shaft 16 and move toward the rotary table 3. It is pressed. Reference numeral 6 is a supply feeder which is a means for supplying the crushed material.

Reference numeral 7 denotes an air inlet provided in a trisection around the casing 2 below the rotary table 3, and the air inlet 7 comprises a square duct 71 fixed to the casing 2 at the opening edge thereof. The damper mounting frame 72 is detachably fixed. As shown in FIG. 3, one end 81 a of the flap 81 is fitted and attached to the pipe member 83 in the damper attaching portion 72, and a rod member to be the shaft 82 of the damper is inserted into the pipe member 83, and each of them is attached with a pin 84. Several fixed gravity dampers 8 are supported by bearings 85.

Several rectifying plates 9 are attached to the square duct 71. When the inside of the casing 2 is sucked by an exhaust fan and air flows in from the air intake 7, the gravity damper 8
Receives the air flow and is lifted as shown by the solid line in FIG. 2 to receive the air, and the air is rectified by the rectifying plate a. The rectified air passes through the air chamber 10 and becomes an ascending airflow a from the annular nozzle 11, and raises the pulverized material pulverized by the rotary table 3 and the pulverizing roller 4 to above the casing 2. The ascended pulverized product is classified into a fine powder and a coarse powder by the classifier 12, and the fine powder is taken out from the discharge port 13 to the outside of the mill as a product by the ascending air flow a. On the other hand, the coarse powder freely falls on the rotary table 3 and is pulverized again.

During this operation, when the exhaust fan is stopped due to a power failure or the like, the air flow is stopped, the gravity damper 8 lifted by the air flow is lowered, and the opening of the air intake 7 is opened as shown by the chain line in FIG. Shut off, vertical roller mill 1
Prevent the crushed substances rising inside from leaking from the air intake 7. When the exhaust fan is restarted and air flow is generated, the gravity damper 8 swings upward, the air intake 7 is opened, and air can be taken into the mill 1.

The air velocity at the air intake 7 is 12 m /
At s, the damper 8 is opened as shown by the solid line in FIG. Further, since the straightening vane 9 is obliquely attached, even if a foreign matter enters and hits the straightening vane 9, the foreign matter bounces downward, does not hit the damper 8, and falls onto a discharge chute (not shown).

[0017]

As described above, according to the present invention, it is possible to reliably prevent the crushed material rising inside the vertical roller mill from leaking to the outside when the rising air flow disappears. Therefore, the working environment is not deteriorated.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional front view of an embodiment.

FIG. 2 is a vertical sectional front view of an air intake of the same embodiment.

3 (a) is a left side view of a main part cut in FIG. 2, and FIG. 3 (b) is an enlarged sectional view of FIG.

[Explanation of symbols]

1 Vertical roller mill 2 casing 3 turntable 4 crushing roller 5 Pressure cylinder 6 supply feeder 7 Air intake 8 Gravity damper 9 Current plate 10 air chambers 11 annular nozzle 12 classifier 13 outlet

Claims (2)

(57) [Claims] 1. A crushing roller 4 is rotatably pressed against a rotary table 3 in a casing 2 with a crushed object interposed therebetween to crush the crushed object between the rotary table 3 and the crushing roller 4, and the casing 2 A vertical type in which the ascending airflow a is taken in from the air intake 7 provided in the casing 2 below the rotary table 3 by inhaling from above and the pulverized material is guided out of the casing 2 along with the ascending airflow a. In the roller mill 1, a vertical roller mill characterized in that the air intake 7 is closed when the upward flow a disappears. 2. A gravity damper 8 is attached to the air intake 7, the gravity damper 8 is rotated and opened by the upward airflow a, and is closed by its own weight when the upward airflow a disappears. The vertical roller mill according to claim 1, wherein the inlet 7 is closed.