JPH0127873Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a tower-type crushing apparatus for dry-pulverizing artificial ores and natural ores such as blast furnace slag and cement clinker.

FIG. 1 is a schematic diagram showing the structure of a dry tower type crusher. 1 is a crusher body, and a screw 3 is attached to a rotating shaft 2 held in the center of the crusher body 1 by appropriate means. An appropriate amount of grinding media is filled in the crusher body 1 below the top of the screw 3. Grinding media generally include diameter
A steel or porcelain ball of about 10 to 40 mm is used.

The screw 3 rotates due to the rotation of the rotating shaft 2,
The charged grinding media rises along the spiral blades of the screw 3 and descends through the circumferential gap between the spiral blades and the crusher body 1. In addition, the raw material to be crushed is supplied from the ore feed port 4, and a fixed amount is supplied by the rotary valve 5.
When introduced into the crusher main body 1, the raw material to be crushed moves together with the crushing medium and is gradually crushed from its surface by grinding between the crushed material and the crushing medium and mutual grinding of the crushed materials.

On the other hand, the gas induced by fan 16 is
The gas enters the pulverizer through the gas intake duct 14 provided at the bottom of the pulverizer main body 1, passes through the packed bed consisting of the pulverizing media and the material to be pulverized, and enters the gas intake duct 14 while entraining a certain amount of the pulverized material. It exits the crusher through the opposing discharge duct 12. At this time, the amount of crushed material discharged from the crusher is changed depending on the amount of gas flowing into the crusher, and the amount of gas flowing into the crusher is adjusted by the damper 15. Incidentally, a batten 13 is installed at the connection between the gas intake duct 14 and the exhaust duct 12 and the crusher to allow gas and the crushed material to pass therethrough, but to prevent the crushing medium from flowing out. In addition, the reason why the crushed material is extracted from the lower part of the crusher is that the pressure of the crushing media increases toward the bottom of the crusher body 1, which increases the grinding effect, and a large amount of fine powder is generated at the bottom of the crusher body 1. be.

The gas and crushed material exiting the crusher main body 1 are sent to a separator 6.
The majority of the pulverized material containing many coarse particles is separated and sent to the classifier 8 via the transporter 7. In addition, the remaining part remains entrained in the gas and passes through the classifier 8.
sent to. The pulverized material sent to the classifier 8 is classified into fine powder and coarse powder, and the fine powder is accompanied by gas and guided to the dust collector 9 to be recovered as a product 11, and the gas passes through the fan 16 and exits the system. It is discharged. In addition, the coarse powder classified in the classifier 8 is transferred to the coarse powder chute 1.
0 into the pulverizer main body 1, and the circulation between the pulverizer main body 1 and the classifier 8 is repeated until it is re-pulverized and becomes fine powder.

In such a crusher, the crusher main body 1
An important factor is the ratio between the amount of grinding media in the grinder and the amount of powder that fills the gaps between the grinding media. In other words, even if the ratio of the weight of the grinding media to the weight of the powder (hereinafter referred to as B/P ratio) in a certain volume of the grinding media packed bed is too large, the field of action for grinding, that is, the point of contact between the grinding media, cannot be effectively used. However, if the B/P ratio is too small, there is a phenomenon in which the grinding efficiency decreases due to the cushioning effect of the powder. Therefore, there is an appropriate range for the B/P ratio within the pulverizer, and in order to efficiently perform pulverization, it is necessary to maintain the B/P ratio within this appropriate range. By the way, when steel balls are used as a grinding medium, their porosity is approximately 0.4, and if the voids are filled with powder with a bulk specific gravity of 1 g/ ^cm3 , the B/P ratio is approximately
However, in actual operation, the B/P ratio may be in a very dense powder state (that is, a state in which there is little contact between steel balls) with a B/P ratio of about 1. For this reason, in the conventional device, the fan 16
A part of the gas induced from the lower side gas intake duct 14 is extracted from the upper part of the crusher main body 1, and the powder is blown up by the gas, increasing the B/P ratio (that is, reducing the powder concentration). (thin) to maintain the B/P ratio within an appropriate range.

However, in this way, the gas is
When the gas is drawn from the bottom side of the crusher body 1
The liquid is not evenly dispersed inside, resulting in drifting. For this reason, the B/P ratio is still small in areas where gas does not pass, and it is difficult to maintain an appropriate B/P ratio even in areas where the flow is biased, resulting in problems. In addition, if the air volume is constant, the exhaust duct 1
2, the amount of gas emitted is smaller, resulting in poor discharge of the pulverized material.

The present invention was proposed in order to solve these conventional drawbacks, and it involves blowing gas uniformly around the entire circumference of the bottom surface of the screw in the crusher body toward the gap formed by the crusher body shell and the screw. We would like to provide a tower-type crushing device that aims to eliminate the uneven flow of gas inside the crusher body, maintain a uniform and appropriate amount of powder in the packed bed of crushing media, and perform crushing efficiently. It is something to do.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The crushing apparatus according to the present invention will be described in detail below based on embodiments shown in the drawings. Note that the same members corresponding to those in the conventional structure are given the same numbers and their explanations will be omitted.

FIG. 2 is a schematic configuration diagram of the crushing device according to the present invention. In the dry tower type crushing device according to the present invention, the shell of the crusher body 1 and the screw A gas duct 17 is installed in which a large number of nozzles are uniformly drilled along the entire circumference to blow gas uniformly over the entire circumference toward the gap formed by the gas duct 17. Intake duct 14
A damper 15 is used to adjust the gas flow rate. Note that other structural relationships are the same as the conventional structure.

When operating the dry tower type crushing apparatus configured in this way, the crushing medium is first given a circumferential velocity by the screw 3, but this circumferential velocity increases as it moves away from the screw 3 in the radial direction. In the vicinity of the shell of the crusher main body 1, it approaches zero. As described above, there is a distribution of circumferential speeds, and pulverization is mainly performed by the shearing force caused by this speed difference. Therefore, the gap between the main shell and the screw 3 is the most effective zone for crushing. Since the gas duct 17 directly injects gas through a large number of nozzles uniformly provided over the entire circumference into the effective zone for pulverization, the B/P ratio of this zone can be adjusted to an appropriate level by appropriately adjusting the gas amount. This makes it possible to maintain high grinding efficiency within a certain range. In addition, sufficient aeration is achieved near the exhaust duct 12 in the crusher body 1 even when some of the gas is vented upwards, and in this invention, the pulverized material is better than when gas is blown from the lower side of the body 1. The discharge is good.

As described above in detail based on the embodiments shown in the drawings, the tower-type crusher according to the present invention has the following features:
A screw fixed to a rotating shaft is installed inside the vertical cylindrical crusher main body, which has a supply port for crushed materials at the top and a discharge port for crushed materials at the bottom. The structure is equipped with a gas injection device such as a gas duct that sprays gas uniformly over the entire circumference toward the gap between the cylindrical crusher body and the screw, eliminating uneven flow of gas within the crusher body and improving the filling of the crushing media. Maintains the amount of powder in the layer uniformly and appropriately,
It becomes possible to perform pulverization efficiently. Also,
According to the present invention, since the gas is blown into the bottom of the lower part of the crusher main body, it has practical effects such as good discharge of the crushed materials.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing the structure of a conventional dry tower type crushing device, and FIG. 2 is a schematic configuration diagram showing the crushing device according to the present invention. 1... Crusher body, 2... Rotating shaft, 3... Screw feed port, 8... Classifier, 12... Discharge duct, 14... Gas intake duct, 15... Damper,
17...Gas duct.

Claims (1)

[Scope of utility model registration request] A screw fixed to a rotating shaft is disposed inside the main body of the vertical cylindrical crusher, which has a supply port for the crushed material at the top and a discharge port for the crushed material at the bottom. A tower-type crushing device characterized by being equipped with a gas injection device that jets gas uniformly around the entire circumference toward the gap between the cylindrical crusher main body and the screw.