JPH0593558U - Preliminary crusher - Google Patents

Abstract

(57) [Summary] [Structure] A classifier 43 is provided directly above the vertical mill 31 via an ascending pipe 42. Only the mixture of the refined powder and the crushed material 37 carried on the carrier air 40 is guided to the classifier 43, and swirls in the swirling cone 51 by passing through a number of vanes 50 whose angles can be adjusted in the circumferential direction. Then, the fine powder and the pulverized product 37 are separated by centrifugal force. The separated refined powder is collected by the refined powder collecting device 57, and the pulverized product 37 is guided to the ball mill 4 by the pulverized product take-out section 61 and is finally pulverized.
It is possible to omit the transportation equipment. Since the fine powder is separated by the classifier 43, over-milling in the ball mill 4 is prevented. Further, since the granular material 2 ′ preliminarily crushed by the vertical mill 31 is blown up by the conveying air 40 and conveyed, even if it is a wet raw material, the conveying air 40 is used as hot gas for preliminary pulverization. It becomes possible to easily dry at the stage.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a preliminary crushing device that performs preliminary crushing of raw materials as a pre-stage before obtaining fine powder by main crushing with a ball mill.

[0002]

[Prior Art]

 FIG. 4 shows an example of a cement manufacturing facility, in which the raw material for cement is crushed in two stages by the preliminary crushing device 20 and the main crushing device 30 to improve the crushing efficiency.

The preliminary crushing device 20 performs preliminary crushing by introducing the cement raw material 2 from the raw material hopper 1 into the preliminary crusher 21 such as a vertical mill or crusher having excellent crushing ability through the raw material supply feeder 3. The pre-crushed powdery particles 22 are guided to a sieve type classifier 25 through a conveyor 23 and a conveying device 24 such as a bucket elevator to be classified.

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 pulverized material 28 containing the refined powder under the sieve separated by the sieve classifier 25 is guided to the main crushing apparatus 30 via the conveyor 29. I try to crush it further.

The present crushing device 30 crushes the crushed product 28 conveyed from the sieve classifier 25 via a conveyor 29 into a horizontal ball mill 4 having an excellent fine pulverizing performance, and a crushed product introducing port 5 at one end in the axial direction. It is introduced from and crushed. 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 coming out from the other end outlet chamber 6 of the ball mill 4 is conveyed to the upper part by a conveying 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 which 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.

[0009]

[Problems to be solved by the device]

 However, in the conventional apparatus as described above, the powder particles 22 crushed by the preliminary crusher 21 are guided to the sieve type classifier 25 through the conveyor 23 and the transfer device 24 so as to be classified. In addition, since the coarse particles 26 classified by the sieve classifier 25 are circulated by the conveyor 27 so as to be returned to the preliminary crusher 21 again, complicated conveying equipment is required and the sieve type is used. Since the classifier 25 is provided independently, there is a problem that the equipment becomes large and the equipment cost increases.

Further, since the sieving type classifier 25 only separates the coarse particles 26 and the pulverized material 28, the pulverized material 28 introduced into the ball mill 4 contains a large amount of the refined powder 13 as a product. Therefore, since the fine powder 13 is pulverized again in the ball mill 4, it becomes over-pulverization, which significantly reduces the pulverization efficiency of the ball mill 4 and further reduces the originally low pulverization ability of the ball mill 4. I had.

Further, in the conventional device, the powder particles 22 preliminarily crushed in the preliminary crusher 21 are guided to the sieve type classifier 25 through the conveyor 23 and the transport device 24 such as a bucket elevator, so that the water content is reduced. If a wet raw material containing a large amount of water is applied to the conventional pre-grinding device 20, there is a problem that adherence and blockage due to residual moisture in the powder and granules 22 occur and operation becomes impossible. It was necessary to equip the dryer separately before feeding it to the machine 21.

The present invention has been made in view of the above-mentioned problems of the related art, and the powdery particles discharged from the upper portion of the vertical mill together with the carrier air are provided directly above the vertical mill via a rising pipe. By classifying the refined powder and the pulverized material to be guided to the ball mill immediately by the classifier, the transportation equipment is omitted, and the refined powder is prevented from being introduced into the ball mill, greatly increasing the pulverizing ability of the ball mill. Furthermore, it is an object to make it possible to dry even a wet raw material in the stage of preliminary crushing.

[0013]

[Means for Solving the Problems]

 According to the present invention, a vertical mill that pulverizes raw materials and pulverizes them with carrier air and discharges them from an upper outlet, an ascending pipe connected directly above the vertical mill, and is attached to the upper part of the ascending pipe. A swirling cone having a number of vanes whose angle can be adjusted in the circumferential direction is provided at the upper end of the swirling cone, and the swirling cone is swirled in the swirling cone by passing the granular material through the vane. A classifier that separates into a fine powder and a crushed product by force, a fine powder collecting device including a fine powder collector and a suction fan connected to the classifier through a suction pipe, and the above-mentioned separate unit A preliminary crushing device, comprising: a crushed product take-out section provided so as to receive the crushed product and guide it to the present crushing device.

[0014]

[Action]

 In the present invention, since the classifier is provided directly above the vertical mill through the ascending pipe, only the mixture of the fine powder and the crushed product carried by the carrier air is guided to the classifier, and the coarse machine is introduced. The particles are separated by gravity before they reach the classifier. Therefore, the classifier separates the refined powder and the pulverized product, the refined powder is collected by the refined powder collecting device, and the pulverized product is guided to the pulverizing device as it is for main pulverization. It is possible to Further, since the refined powder is separated by the classifier, only the pulverized product is introduced into the ball mill, and the refined powder is not mixed in, so that overpulverization in the ball mill is prevented. Further, since the powder fluid preliminarily crushed by the vertical mill is blown up with the carrier air to be conveyed, even if the wet raw material is used, the carrier air is used as the hot gas to facilitate the premilling step. It can be dried.

[0015]

【Example】

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

FIGS. 1 and 2 show an example of the preliminary crushing device 36 of the present invention, and FIG. 3 shows an example of applying the preliminary crushing device 36 of the present invention to the cement manufacturing facility of FIG. In the figure, 31 is a vertical mill, and the vertical mill 31 is a grinding table 33 rotated by a driving device 32, and a grinding roller 34 which is pressed against the grinding table 33 and rotated by the rotation of the grinding table 33. The cement raw material (raw material) 2 introduced from the raw material supply pipe 35 is crushed by the crushing table 33 and the crushing roller 34, and the crushed powder and granules 2 ′ are under the crushing table 33. The air nozzle chamber 38 provided on the outer circumference is floated up by the carrier air 40 introduced from the carrier air introduction port 39, and is discharged from the upper outlet 41.

An ascending pipe 42 of a required length connected to the upper outlet 41 is provided directly above the vertical mill 31, and a classifier 43 is attached to the upper part of the ascending pipe 42. The ascending pipe 42 effectively separates the coarse particles in the granular material 2 ′ by gravity so that the upward flow of the granular material 2 ′ rises uniformly and stably, and the coarse particles in the granular material 2 ′ are separated into the vertical mill 31. It has a large diameter so that it can be dropped again.

The classifier 43 is a classifier casing 46 in which a required position in the circumferential direction is fixed to the ascending pipe 42 by a fixing member 45 in a state in which the upper end of the ascending pipe 42 is surrounded with a required interval 44. have. The classifier casing 46 has an inclined portion 47 that extends upward from the lower end fixed to the rising pipe 42, an introduction portion 48 that narrows upward from the upper end of the inclined portion 47, and an upper end of the introduction portion 48. It has a closing board 49.

Inside the classifier casing 46, a swirl cone 51 having a large number of vanes 50 whose angles can be adjusted in the circumferential direction at the upper end and narrowing downward at the lower end is introduced to the outer periphery thereof. The space 52 is provided in an annular shape, and at the lower end opening of the turning cone 51, an upper part is formed in a cone shape and a lower part is formed in an inverted cone shape having a smooth curved surface shape. A rectifying body 53 is provided at the lower end of the swirling cone 51 with an annular gap 54 therebetween, and a top plate 49 inside the vane 50 has a fine powder collector 55 and a suction fan 56. The device 57 is connected via a suction tube 58.

At the lower end of the classifier casing 46, a recovery inclined surface 59 that is inclined at a required inclination angle and airtightly surrounds the outer peripheral surface of the ascending pipe 42, and a lowermost end portion of the recovery inclined surface 59 are provided. A crushed material take-out section 61 composed of the inclined take-out tube 60 is provided.

In FIG. 1, when the raw material 2 is supplied from the raw material supply pipe 35 and the pulverizing table 33 is rotated by the driving device 32, the suction fan 56 of the fine powder collecting device 57 is driven, The powder and granules 2 ′ crushed by the crushing roller 34 and the crushing roller 34 float up in the vertical mill 31 by the carrier air 40 introduced from the carrier air introduction port 39 and rise in the riser pipe 42 from the upper outlet 41. .

At this time, the coarse particles are effectively separated by gravity while ascending in the ascending pipe 42, and in the introduction space 52, the fine powder 13 and the pulverized material 37 carried on the carrier air 40 are separated. Only the mixture will be guided, and the separated coarse particles fall on the crushing table 33 of the vertical mill 31 and are crushed again.

The mixture of the fine powder 13 and the pulverized material 37 rising in the ascending pipe 42 is guided to the vane 50 from the introduction space 52 and passes through the vane 50 together with the carrier air 40 to generate a turning force. The fine powder 13 and the crushed product 37 are classified by the centrifugal force of the swirling cone 51 which is given.

That is, since the pulverized material 37 having a relatively large particle size has a large momentum, it deviates from the swirling flow of the carrier air 40 and descends along the inner peripheral surface of the swirling cone 51, and The fine powder 13 falls from the gap 54 at the lower end of the inlet 51 into the rising pipe 42, while the fine powder 13 is collected by the fine powder collector 55 of the fine powder collecting device 57 via the suction pipe 58.

Further, the pulverized material 37 charged into the ascending pipe 42 is blown up again by the ascending carrier air 40, but the energy of the carrier air 40 for floating the pulverized material 37 is naturally limited. Therefore, while rising in the introduction space 52, the crushed material 37 having a large particle diameter (heavy weight) gradually falls to the inclined portion 47 of the classifier casing 46, and the crushed material is taken out from the interval 44 at the lower end of the inclined portion 47. It falls to the recovery inclined surface 59 of the part 61, is guided to the ball mill 4 of the main crushing device 30 via the inclined take-out pipe 60, and is further crushed.

Therefore, according to the above-mentioned embodiment, the refined powder 13 and the pulverized product 37 are separated in the classifier 43 provided directly above the vertical mill 31, and the refined powder 13 is recovered by the refined powder collecting device 57, Since the crushed product 37 is directly guided to the ball mill 4 for main crushing, it is possible to omit the transportation equipment for the crushed raw material (powder and granules 2 ′).

Further, since the refined powder 13 is separated in the classifier 43, only the pulverized material 37 is introduced into the ball mill 4, and the refined powder 13 is introduced and over-pulverized. Therefore, the grinding efficiency of the ball mill 4 can be increased and the grinding ability can be increased.

Further, since the powder particles 2 ′ preliminarily crushed by the vertical mill 31 are blown up by the carrier air 40 to be carried, the carrier air 40 is used as a hot gas even if it is a wet raw material. By doing so, it can be easily dried at the stage of preliminary pulverization.

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 it is necessary to further grind a pre-crushed crushed product, and crushing with a pre-crusher It is needless to say that the raw materials which have not been discharged are discharged from the preliminary crusher without carrying them by air, and other various changes can be made without departing from the scope of the present invention.

[0030]

[Effect of the device]

 According to the preliminary crushing device of the present invention, the classifier is provided directly above the vertical mill through the ascending pipe so that only the mixture of the fine powder and the crushed product carried in the carrier air is guided to the classifier. In this method, the refined powder is separated into the refined powder and the crushed product, and the refined powder is collected by the refined powder collecting device, and the crushed product is directly guided to the ball mill of the crushing device. It can be simplified.

Further, since the refined powder is separated by the classifier, only the pulverized product is introduced into the ball mill, and the refined powder is not mixed in. Therefore, overpulverization in the ball mill can be prevented, The grinding ability of the ball mill can be greatly increased.

Further, since the powder and granules preliminarily crushed by the vertical mill are blown up by the conveying air to be conveyed, the wet air can be preliminarily crushed by converting the conveying air into hot gas. It can be easily dried in stages.

[Brief description of drawings]

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

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

FIG. 3 is a system diagram when the preliminary crushing device 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]

 2 Raw material 2'Powder granules 13 Fine powder 30 Main crusher 31 Vertical mill 36 Preliminary crusher 37 Crushed product 40 Carrier air 41 Upper outlet 42 Upcomer 43 Classifier 50 Vane 51 Swiveling cone 55 Fine powder collector 56 Suction fan 57 Fine powder collecting device 58 Suction tube 61 Crushed material take-out section

Claims (1)

[Scope of utility model registration request] 1. A vertical mill for suspending a powder or granular material obtained by crushing a raw material by carrier air and discharging it from an upper outlet, a rising pipe connected directly above the vertical mill, and attached to an upper part of the rising pipe. And inside is provided with a swirling cone having a plurality of vanes whose angles can be adjusted in the circumferential direction at the upper end, and swirling in the swirling cone by passing the powder and granules through the vanes to produce fine powder by centrifugal force. A classifier that separates into a crushed material, a fine powder collector that is connected to the classifier through a suction pipe and a suction fan, and a fine powder collector that receives the crushed material separated by the classifier A preliminary crushing device, comprising: a crushed product take-out section provided so as to be guided to the crushing device.