JPS5939352A - Dry system tower type crusher for ore, etc. - 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 The present invention relates to an improvement in a dry base type crushing apparatus for artificial ores such as blast furnace slag and cement clinker, and natural ores.

FIG. 1 shows an outline of the structure of a conventional dry base type crusher. In FIG. 1, reference numeral 1 denotes a crusher body, and a screw 6 is attached to a rotating shaft 2 held in the center of the crusher body by appropriate means.
Fill the appropriate amount of grinding media below the top of the Steel or magnetic balls with a diameter of about 10 to 40 mm are generally used as the grinding media.

The screw 6 rotates by 20 rotations of the rotary shaft, and the filled grinding medium rises along the spiral blades of the screw filter and descends through the circumferential gap between the spiral blades and the crusher body. In this way, when the raw material to be crushed is supplied from the feed port 4 and a certain amount is fed into the crusher main body by the rotary valve 5, the raw material to be crushed moves together with the crushing medium, and the grinding between the raw material to be crushed and the crushing medium occurs. By mutual grinding of the ground material and the ground material, the material is gradually ground from its surface.

On the other hand, a blower 8 blows high-pressure air from below the crusher main body.
Send by. This air rises inside the pulverizer main body filled with the pulverizing media and the object to be pulverized, carries the finely pulverized material obtained as described above, and is led out of the pulverizer main body. The air accompanied by this finely pulverized material is led to cyclone 6,
Here, the fine powder is separated from the air and the air is circulated again by the blower 8. Fine powder, which is a pulverized product, is taken out from the take-out lower. The reason why high-pressure air is sent from the bottom of the pulverizer body is that the grinding effect on the material to be pulverized supplied to the pulverizer body is greater as the pressure from the pulverizing media increases the further down the pulverizer body is. This is because a large amount of fine powder is generated at the bottom of the crusher main body.

The conventional device described above has the following drawbacks.

(1) Since the fine powder is conveyed through air from the bottom to the top of the high interlayer filled with the grinding media and materials to be ground, there is a large air pressure loss in the main body of the grinder, and high pressure air is required. Power increases.

(++) Possibly, the coarse particles of the material to be crushed that have come to the bottom of the crusher body are not transported upwards and accumulate, and the pressure loss of the air in this area increases abnormally, sometimes along the screw shaft where there is relatively little resistance. Bumping occurs, making it impossible to stably control the particle size of the pulverized product.

In addition, the amount of air passing through the pulverizer body is related to the required particle size of the pulverized product, and in actual operation, it is necessary to maintain an appropriate amount. It is not possible to freely change the air volume.

6φ In order to improve the grinding efficiency and control method of the particle size of the ground product, attempts were made to adopt a closed-circuit grinding method that combines a grinder with a classifier to a conventional dry tower type grinder, but it is difficult to implement for the following reasons. It is.

(a) When coarse particles discharged from a classifier that require re-grinding are fed from the bottom of the crusher main body, the fed coarse particles stay at the bottom or are entrained upward by air. Most of this air flows along the screw shaft with relatively small pressure drop, so the coarse particles are discharged from the top of the mill without entering between the layers of the grinding media where they are effectively crushed, allowing the coarse particles to be re-pulverized. cannot be done effectively.

In addition, in the case of a wet base type crusher, water is passed upward from the bottom of the crusher body. In this method, since the particle dispersion effect of water is much greater than that of air, coarse particles can penetrate between the layers of the grinding media. Therefore, in the case of a wet type, it is possible to adopt a closed circuit pulverization method, and the closed circuit pulverization method has been put into practical use.

(Publication of Utility Model Publication No. 52-4'8057 and Utility Model Publication No. 45-3
(Refer to Publication No. 4056) (b) Even if you try to feed the coarse particles discharged from the classifier from the side of the middle part of the crusher main body, the crushing media and the material to be crushed are densely packed, so it is difficult to feed back the coarse particles sufficiently. cannot be ensured, making it practically impossible to use a closed circuit system.

(c) When the coarse particles discharged from the classifier are supplied to the upper part of the crusher main body, the supplied coarse particles are immediately discharged outside the crusher by an air flow and are not subjected to the crushing action.

In order to improve the drawbacks of the conventional dry tower type crusher, such as the high pressure drop in the crusher body and the abnormal pressure drop increase and decrease in crushing efficiency due to the accumulation of coarse particles at the bottom of the crusher, the present invention has been developed from the bottom of the crusher. This was proposed with the aim of providing a highly efficient, high-performance dry tower type crusher that extracts the crushed material and sends it to the classifier, and returns the coarse particles to the crusher body to perform closed circuit crushing. The vertical cylindrical pulverizer body has an air supply port at the bottom, which has a pulverized material supply port at the top, and a rotary screw that is driven and rotated by a drive source at a predetermined speed in a predetermined direction by a drive source inside. The present invention relates to a dry base type crushing apparatus for minerals, etc., characterized in that it is provided with a pulverized material discharge port facing the air supply port and connected to the classifier inlet.

The present invention will be specifically explained below with reference to an embodiment shown in FIG.

In FIG. 2, 1 is a vertical cylindrical crusher body, 2 is a rotating shaft held in the center of the crusher body by appropriate means, and 6
is a screw attached to the rotating part 1i1112, and an appropriate amount of grinding medium is filled in the part below the top of the screw 6 in the main body 1 of the grinder. Grinding media generally have a diameter of 10
A steel or porcelain ball of about 40M is used.

4 is a pulverized material supply port for the raw material to be pulverized, and 5 is a pulverized material feeder using a rotary valve or the like, and the structure, operation, and mutual relationship of these members are almost the same as those of the conventional apparatus described above. (Equivalent parts are given the same reference numerals. 14 is the crusher main body 1
A duct (air supply port) that introduces gas such as air into the bottom of the
Reference numeral 12 denotes a duct for extracting the pulverized material by gas from the lower part of the pulverizer main body 1 (pulverized material discharge port) As this gas, outside air, exhaust gas from other equipment, or exhaust gas from the blower 16 can be used. 1 is a batten that prevents the crushing media in the crusher body 1 from entering the duct 12 and 14, and allows gas and crushed materials to pass through; 15 is the amount of gas introduced into the crusher body 1; 6 is a chamber for separating a part of the pulverized material extracted from the pulverizer main body 1 from the gas; 7 is a transporter for feeding the pulverized material into the classifier 8; It is also possible to omit the chamber 6 and the transporter 7 and connect the 12 ducts directly to the classifier 8. Reference numeral 10 denotes a chute for returning the coarse particles discharged from the classifier 8 to the crusher main body, and the coarse particle discharge port of this chute 10 may be connected to a chute that connects the rotary valve 5 and the crusher main body 1. can. 9 is a cyclone for collecting fine powder classified by the classifier 8, 16 is a blower for attracting gas, and 11 is a pulverized product. Note that the classifier 8 is usually an air classifier. The entrained gas of the ground material leaving the chamber 6, which separates the ground material from the gas, can also be introduced directly into the cyclone 9, depending on the required particle size of the ground product.

In Fig. 2, solid lines with arrows indicate the pulverized material, dotted lines with arrows indicate the flow of gas, and dashed lines with arrows indicate the flow of gas accompanied by the pulverized material.

An embodiment of the apparatus of the present invention is constructed as described above, and the material to be crushed is fed between the crusher body 1 by the feeder 5 via the pulverized material supply port 4. The behavior of the grinding media (balls) in the grinder and the mechanism of grinding are the same as in the conventional one. In the present invention, the material to be crushed is supplied from the upper part of the crusher body 1 and reaches the lower part of the crusher body 1 while being subjected to the crushing action. It is guided through the batten 16 to a chamber B located outside the crusher. The amount of crushed material discharged from the crusher body 1 is adjusted by changing the amount of gas introduced into the crusher body 1. Therefore, by adjusting the damper 15, the amount of crushed paper remaining in the crusher body can be controlled. Most of the pulverized material introduced into the chamber B by the gas is separated from the gas here, and guided by the transporter 7 to the classifier 8 where it is classified into fine powder and coarse powder. On the other hand, the gas accompanied by the pulverized material discharged from the chamber 6 is also led to the classifier 8 and classified into fine powder and coarse powder. The fine powder classified in the classifier 8 is entrained in gas and collected by the cyclone 9 to become a pulverized product 11.

The gas that passes through the damper 15, enters the crusher main body 1, and further passes through the chamber 6, classifier 8, and cyclone 9 is induced by the blower 16. The coarse particles discharged from the classifier 8 are fed into the pulverizer from the upper part of the pulverizer main body 1 in order to be pulverized again. The coarse particles are mixed with the material to be crushed supplied by the feeder 5, and are subjected to the same pulverizing action as the material to be crushed. The above-mentioned pulverization method is a so-called closed-circuit pulverization method that combines a pulverizer and a classifier.

Since the device of the present invention has the above-described configuration and operation, according to the present invention, (1) gas is introduced from the bottom side of the crusher main body, and the gas inlet 14 (air supply port ) By providing an outlet 12 for the gas and pulverized material on the side of the pulverizer main body opposite to the pulverizer main body, the pressure drop in the pulverizer main body is significantly reduced compared to the conventional method (gas is introduced from below and exhausted from above).

(2) Conventional dry base type crushers could not achieve a closed-circuit crushing system, but with the present invention, the coarse particles discharged from the classifier are as effective as the materials to be crushed that are supplied to the crusher main body. This allows for the adoption of a closed-circuit crushing method.

By adopting a closed-circuit pulverization method that combines this basic pulverizer and a classifier, it is possible to prevent a decrease in pulverization efficiency due to the cushioning effect of fine powder within the pulverizer, and by combining it with a classifier with high classification performance, it is possible to improve the pulverization efficiency. It is possible to significantly improve the

Can you list some practical effects?

As shown in the figure, if a damper 15 is provided in the air supply port 14 so that the amount of air can be adjusted, the amount of material to be crushed that stays in the crusher body can be controlled, and the difference in the pulverizability of the material to be crushed can be controlled. This has the advantage that the residence time of the material to be crushed in the crusher can be obtained in accordance with the above conditions, and the crushing efficiency can be improved.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of a conventional device, and FIG. 2 is a schematic side view of an embodiment of the present invention. 1: Pulverizer main body, 2: Rotating shaft, 6: Screw, 4: Pulverized material supply port, 8: Classifier, 12: Pulverized material discharge port, 14:
Air supply port.

Claims (1)

[Claims] The vertical cylindrical pulverizer body has an air supply port at the bottom, which has a pulverized material supply port at the top, and a rotary screw that is driven and rotated by a drive source at a predetermined speed in a predetermined direction by a drive source inside. 1. A dry base type crushing device for minerals, etc., characterized in that a crushed material discharge port facing the same air supply and connected to an inlet of a classifier is provided.