JPH0518681U - Multi-stage classifier - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the classification accuracy with a small and simple structure, and to facilitate post-treatment according to the particle size of the powder after classification. [Structure] Casing 3 having inlet 36 in the tangential direction
A centrifugal classifier 32 having a classifying blade 38 inside 7 and connecting the classifying blade 38 to a fine powder collecting device 35 via a suction pipe 43 and having a crushed material discharge port 40 at the lower part of the casing 37; Between the outlet 44 and the inlet 45 in the casing 46, the casing 46 has an outlet 44 communicating with the inlet 36 of the centrifugal classifier 32 and an inlet 45 facing the outlet 44. A collision classifier 33 having a collision plate 48 extending in the vertical direction and having a coarse particle discharge port 47 at the lower portion of the casing 46, and a raw material supply pipe 5 at a side portion.
The vertical ascending pipe 51 to which 0 is connected is connected to the upper end of the collision type classifier 33 at the upper end thereof, and the lower end of the vertical rising pipe 51 is provided with a gravity type classifier 34 having a coarse particle discharge port 52.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a multistage classifier.

[0002]

[Prior Art]

 FIG. 4 shows an example of the case where the cement raw material in the cement manufacturing facility is pulverized in two stages by the preliminary pulverizing device 20 and the main pulverizing device 30 to improve the pulverizing efficiency. The cement raw material 2 is preliminarily crushed by the preliminary crusher 21 such as a crusher or a roller mill via the raw material supply feeder 3, and the preliminarily crushed powder particles 22 are passed through a conveyor 23 and a conveyor device 24 such as a bucket elevator. It guides to the sieve type classifier 25 to perform classification.

The sieve classifier 25 includes an inclined sieve plate 25 a and a vibration generator 25 b that vibrates the sieve plate 25 a, and coarse particles on the sieve separated by the sieve classifier 25. 26 is returned again to the raw material supply feeder 3 via the conveyor 27, and the crushed material 28 under the sieve separated by the sieve classifier 25 is passed via the conveyor 29 to the horizontal ball mill 4 having excellent fine pulverization performance. The crushed material is introduced through the crushed material introduction port 5 at one end in the axial direction to perform the main crushing. In the ball mill 4, a large number of steel balls (balls) or cylindrical pebbles are packed in a cylindrical body that rotates about a substantially horizontal axis, and the crushed material 28 is crushed.

The crushed material 7 discharged from the other end outlet chamber 6 of the ball mill 4 is transferred to the upper part by a transfer device 8 such as a bucket elevator, and then guided to the pneumatic classifier 10 via an air slide 9 or the like. It is like this.

The air type classifier 10 utilizes the circulating gas 12 by a circulating fan 11 that circulates by partially sucking the atmosphere or hot gas to pulverize the pulverized material 7 into a fine powder (product) 13 and a return powder 14. The return powder 14 classified by the air classifier 10 is circulated through the air slide 15 to the crushed material introduction port 5 of the ball mill 4, and the air classifier 10 is also used. The refined powder 13 classified in step 3 is taken out as a product through the refined powder carry-out air slide 16.

The outlet chamber 6 of the ball mill 4 is connected to a dust collecting fan 19 via a ball mill dust collector 18 by a suction pipe 17, and a part of the circulating gas 12 is guided to the ball mill dust collector 18. The fine powder 13 is separated by the ball mill dust collector 18 and the separated fine powder 13 is fed to the fine powder carry-out air slide 16.

[0007]

[Problems to be solved by the device]

 However, in the conventional apparatus as described above, the powdery particles 22 preliminarily crushed by the preliminary crusher 21 are converted into coarse particles 26 by the sieving type classifier 25 having the vibrating sieve plate 25a. The crushing efficiency is low because the classification accuracy is low and a large amount of the crushed material 28 and the refined powder 13 adhere to the coarse particles 26 and are mixed and returned to the preliminary crusher 21. In addition, the pulverized product 28 introduced into the ball mill 4 contains a large amount of fine powder 13 as a product, and therefore the ball mill 4 will pulverize the fine powder 13 again. As a result of crushing, the crushing efficiency of the ball mill 4 is significantly reduced, and there is a problem that the crushing ability of the ball mill 4 is reduced.

The present invention has been made in view of the above-mentioned conventional problems, and has a simple structure and can improve classification accuracy, and requires post-treatment depending on the particle size of the classified powder. The purpose is to provide an optimal multi-stage classifier in some cases.

[0009]

[Means for Solving the Problems]

 According to the present invention, a casing having an inlet in the tangential direction is provided with a classifying blade, the outlet of the classifying blade is connected to a fine powder collecting device through a suction pipe, and a crushed material discharge port is provided at the lower part of the casing. A centrifugal classifier having a casing having a casing formed at the top with an outlet communicating with the inlet of the centrifugal classifier and an inlet facing the outlet, and between the outlet and the inlet in the casing A collision classifier equipped with a collision plate extending in the vertical direction and having a coarse particle discharge port at the lower part of the casing, and an upper end of a vertical riser pipe with a raw material supply pipe connected to the side of the collision classifier at the inlet of the collision classifier. It is characterized by being equipped with a gravity type classifier which is connected and has a coarse particle discharge port at the lower end, and through which a powder raising air can be introduced through a louver provided on a conical wall leading to the discharge port. It is related to a multi-stage classifier.

[0010]

[Action]

 In the present invention, by driving the fine powder collecting device, the centrifugal classifier, the collision classifier, and the gravity classifier are sucked through the suction tube, and the gravity classification is performed from the raw material supply pipe. A predetermined amount of raw materials such as powder and granules are fed into the vertical rising pipe of the machine. Then, the raw material floats in the pipe due to the vertically rising air flow and is introduced into the collision type classifier from the inlet from the upper end. At this time, the heavy-weight coarse particles mixed in the raw material are dropped by gravity and taken out from the coarse-particle outlet.

The raw material guided to the collision type classifier collides with the collision plate to separate coarse particles and drop into the coarse particle discharge port, and the remaining pulverized particles from which the coarse particles have separated collide with each other. It penetrates the lower end of the plate and is tangentially introduced into the centrifugal classifier from the inlet.

The pulverized material introduced into the centrifuge is separated by the centrifugal force and dropped to the pulverized material discharge port, and the refined powder that has passed through the classification blade is guided to the refined powder collector through the suction pipe. Recovered as a product.

By combining the gravity classifier, the collision classifier, the centrifugal classifier, and the fine powder collecting device as described above, the coarse particles and the fine powder can be efficiently removed and the particle sizes can be made uniform. The crushed product can be accurately separated and taken out, and therefore, the crushing efficiency in the case where the crushed product is further crushed can be significantly improved.

[0014]

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an example of the multi-stage classifier 31 of the present invention, and FIG. 3 shows an example of the multi-stage classifier 31 of the present invention applied to the cement manufacturing facility of FIG. ing. In the multi-stage classifier 31, a centrifugal classifier 32, a collision classifier 33, and a gravity classifier 34 are integrally connected, and a fine powder collecting device 35 is connected to the centrifugal classifier 32. Have a configuration.

The centrifugal classifier 32 includes a classification blade 38 inside a casing having an inlet 36 in the tangential direction, and air introduced from the inlet 36 passes through a scroll-shaped flow path 39. It is designed to be uniformly guided to the outer circumference of the classifying blade 38, and a crushed material discharge port 40 is formed in the lower portion of the classifying blade 38 in the casing 37. The classifying blade 38 can pass only the fine powder 13 on the air and guide it inside, and the classifying blade 38 may be a rotary type or a fixed type.

The fine powder collecting device 35 includes a fine powder collecting device 41 and a suction fan 42. The fine powder collecting device 35 is connected to the inner outlet of the classification blade 38 of the centrifugal classifier 32 through a suction pipe 43. There is.

The collision classifier 33 includes a casing 46 having an outlet 44 communicating with the inlet 36 of the centrifugal classifier 32 and an inlet 45 facing the outlet 44 in the upper portion. A coarse-grain discharge port 47 is formed below 46, and a collision plate 48 extending in the vertical direction is provided between the outlet 44 and the inlet 45 inside the casing 46 to form a U-shaped passage. Forming 49.

The gravity classifier 34 bends the upper end of a vertical rising pipe 51 connected to a raw material supply pipe 50 for supplying the cement raw material (raw material) 2 from the conveying device 24 to the side portion, and collides the collision type classifier. An air intake 54 having a louver 53 at the lower portion is connected to the inlet 45 of the machine 33, and a coarse-grained substance outlet 52 is formed at the lower end. The coarse particles 26 from the coarse particle discharge ports 47 and 52 of the gravity type classifier 34 and the collision type classifier 33 are returned to the preliminary crusher 21 via the conveyor 27.

Further, in the case shown in the drawing, the outlet chamber 6 of the ball mill 4 and the pneumatic classifier 10 are connected to the suction pipe 43 of the fine powder collecting device 41 to collect the fine powder 13 collectively.

In the multi-stage classifier 31 described above, the suction fan 42 of the fine powder collecting device 35 is driven to drive the centrifugal classifier 32, the collision classifier 33, and the gravity classifier through the suction pipe 43. In the state where the machine 34 is sucked, the raw material supply pipe 50 supplies the raw material such as the granular material 22 to the vertical rising pipe 51 of the gravity type classifier 34 by a predetermined amount. Then, the raw material is levitated in the vertical ascending pipe 51 by the ascending air flow from the air intake 54 and is introduced into the collision type classifier 33 from the upper end through the inlet 45. At this time, the heavy coarse particles 26 mixed in the raw material fall due to gravity and are taken out from the coarse particle outlet 52.

The raw material guided to the collision type classifier 33 collides with the collision plate 48 to separate the coarse particles 26 and drops into the coarse particle discharge port 47, and the coarse particles 26 are separated into pulverized materials. 28 passes through the lower end of the collision plate 48 and is introduced tangentially from the introduction port 36 into the centrifugal classifier 32.

The crushed material 28 introduced into the centrifugal separator 32 falls to the crushed material discharge port 40 by centrifugal force, and the fine powder 13 passing through the classification blade 38 is sucked from the suction pipe 43 to the fine powder collecting device 35. To be collected as a product and sent to the fine powder carry-out air slide 16.

By combining the gravity classifier 34, the collision classifier 33, the centrifugal classifier 32, and the fine powder collecting device 35 in this way, the coarse particles 26 and the fine powder 13 are accurately separated. It is possible to separate and take out the pulverized product 28 having a uniform grain size, and thus the pulverization efficiency in the case where the pulverized product 28 is guided to the ball mill 4 or the like and further pulverized can be greatly improved.

Further, according to the above, since the refined powder 13 is separated by the multi-stage classifier 31, it is prevented that the refined powder 13 is introduced into the ball mill 4 and is excessively pulverized. The grinding efficiency of No. 4 can be increased to increase the grinding capacity.

It should be noted that the present invention is not limited to the above-mentioned embodiment, and can be applied to various devices in the case where a post-treatment such as further crushing a classified crushed product is required, and the like. It goes without saying that various modifications can be made without departing from the scope of the present invention.

[0027]

[Effect of the device]

 According to the multi-stage classifier of the present invention, the gravity classifier, the collision classifier, the centrifugal classifier, and the fine-particle collecting device are combined and provided in a compact structure. In this case, the coarse particles and the fine powder can be separated accurately and efficiently, and the crushed product with a uniform particle size can be taken out. Therefore, when the post-processing such as further crushing the crushed product is performed. In this case, the handling becomes easy, and the excellent effect that the pulverization efficiency can be greatly improved can be obtained.

[Brief description of drawings]

FIG. 1 is a partially cut front view showing an embodiment of the present invention.

FIG. 2 is a plan view of FIG. 1 viewed from a II-II direction.

FIG. 3 is a system diagram when the multi-stage classifier of FIG. 1 is applied to a cement manufacturing facility.

FIG. 4 is a system diagram showing an example of a conventional cement manufacturing facility.

[Explanation of symbols]

 32 Centrifugal classifier 33 Collision classifier 34 Gravity classifier 35 Fine powder collection device 36 Inlet port 37 Casing 38 Classification blade 40 Crushed material discharge port 43 Suction tube 44 Exit 45 Inlet 46 Casing 47 Coarse particle discharge port 48 Collision plate 50 Raw material supply pipe 51 Vertical riser pipe 52 Coarse grain discharge port

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location B07B 7/04 8925-4D 7/08 8925-4D

Claims (1)

[Scope of utility model registration request] 1. A classifying blade is provided inside a casing having an inlet in the tangential direction, the outlet of the classifying blade is connected to a fine powder collecting device via a suction pipe, and a pulverized material discharge port is provided at the lower part of the casing. A centrifugal classifier having, a casing having an outlet communicating with the inlet of the centrifugal classifier and an inlet facing the outlet formed in the upper portion, and between the outlet and the inlet in the casing. A collision type classifier having a vertically extending collision plate and having a coarse particle discharge port at the lower part of the casing, and an upper end of a vertical riser pipe having a raw material supply pipe connected to a side portion thereof as an inlet of the collision type classifier. A multi-stage classifier, characterized in that it is provided with a gravity classifier that is connected and has a coarse-grained material discharge port at the lower end.