JP2015029954A - Paddle for rotation processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lengthen the service life of a paddle 10 while suppressing the cost by specifying a portion for hardfacing welding 14.SOLUTION: In a pug mill, rectangular plate shaped paddles 10 are provided, inclining their width direction, on an outer peripheral surface of a rotary shaft 2 in an axial direction provided in a gutter-shaped casing 1. In each paddle 10, a rectangular plate shaped plate piece 12 made of SS400 is fastened to a fitting piece 11 welded to the rotary shaft 2 with a bolt 13, and hardfacing welding 14 is applied to required portions of the plate piece 12. The hardfacing welding 14 is applied by each required length L, Land Lto a top face, front and rear faces and both side end faces in a projecting direction of the plate piece 12 from the top face end edges, etc. to the insides. As the hardfacing welding 14, hardfacing welding in which tungsten carbide (WC) is dispersively bonded to a high carbon (C) high chromium (Cr) based material is used, and the hardness Hv is 600 or more. The service life of the paddle 10 is lengthened by the hardfacing welding 14. Since the hardfacing welding 14 is not applied to a part 12c of the rear face, it is advantageous in term of cost.

Description

  The present invention relates to a paddle of a rotary processing machine such as a pug mill and a repair method thereof.

  For example, a Pag Mill, which is one of the rotary processing machines, will be described with reference to FIG. 1 showing an embodiment of the present invention. A paddle 10 projecting in the radial direction is provided on the outer peripheral surface of the steel plate, and the object to be processed put into the casing 1 by the rotation of the rotary shaft 2 in the direction of the arrow is mixed (kneaded) while being fed in one direction by the paddle 10.

In this rotary processing machine, if the object to be processed is hard such as ceramic, ore, or coal, wear of the paddle 10 becomes a problem.
In order to solve the problem, as shown in FIG. 7, a paddle 3 is constructed by bolting a rectangular plate-shaped plate piece 3 b made of high chromium cast iron to the mounting piece 3 a of the rotating shaft 2 to improve wear resistance. There is something. However, the paddle 3 is worn about like 1.5 months and the tip of the plate piece 3b is worn from the chain line to the solid line.
Further, as a means for further reducing wear (improving wear resistance), a wear-resistant layer is formed by hard welding on the portion of the paddle plate piece 3b that is easily worn (summary of Patent Document 1). .

JP 2009-61431 A

The above-mentioned hard build-up welding drastically improves the life of the portion where the wear-resistant layer is formed by the build-up welding. For this reason, in order to improve the life of the paddle, it is preferable to perform hardening build-up welding over the entire surface of the paddle plate piece 3b. However, since the overlay welding material is expensive and welding is complicated, the cost is increased.
Under such circumstances, the above-described conventional hard welding is performed by using the entire top surface in the radial direction of the rotating shaft (paddle protruding direction) and the rotational direction b of the paddle (rotating counterclockwise as viewed from the right side in FIG. 7) front surface ( It is applied to the entire required length toward the inside in the protruding direction of the front surface in the feed direction a (see Patent Document 1, FIGS. 5 to 8).

  In the rotary processing machine in which the paddle is provided with the width direction inclined with respect to the circumferential direction of the rotation axis in the actual state described above, the portion of the hardened weld to the paddle is specified, and the cost is reduced. The problem is to improve the life of the paddle.

In order to achieve the above object, the rectangular plate-shaped paddle has a smooth mixing and feeding action, and it is easy to specify the wear site in the action. First, the wear course of the rectangular plate-like plate piece 3b in FIG. 7 is observed. did.
In this observation, when the paddle 3 is rotated in the direction of the arrow b, the workpiece is mixed while being moved in the direction of the arrow a. At this time, the site where the friction with the workpiece is generated is the top surface of the plate piece 3b. It was confirmed that the width was a constant width from the top edge of the front end surface in the rotational direction b (feed direction a rear side end surface) and the front in the rotational direction (front surface in the feed direction) toward the inside of the paddle protruding direction.
Next, when hardened and welded to the top surface of the plate piece 3b, the front end surface in the same rotational direction, and the front surface, the width direction of the paddle (the lateral direction with respect to the protruding direction of the rectangular plate-shaped paddle) is in the circumferential direction of the rotational axis. Since the inclined surface is inclined, the phenomenon that the workpiece is worn around the rear surface from the front end surface in the rotational direction to the rear side in the rotational direction of the rear surface is confirmed. On the other hand, the wear on the rear surface was gradually becoming shallower in the width direction. When the wear on the front and rear surfaces in the rotational direction where the plate piece 3b is exposed (the portion where the hardfacing welding is not performed) proceeds, wear holes penetrating from the front end face toward the rear face in the front and rear faces.

Based on these confirmation operations, the present invention first performs hardening build-up welding on the top surface of the rectangular plate base material (plate piece 3b) in the protruding direction, and the front end surface and the same end surface of the rectangular plate base material in the rotational direction. Hardening welding is performed on the front surface in the rotation direction for each required length in the protruding direction from the edge of the top surface toward the inside in the protruding direction.
The required length in the protruding direction from the top surface edge to the inside is appropriately determined by experiment, actual operation or the like according to the object to be processed.

Next, according to the present invention, on the rear surface in the rotation direction of the rectangular plate-shaped base material, hardening build-up welding is applied to a portion that enters the required length in the width direction from the edge of the front end surface in the rotation direction, and the other portions are cured. The build-up welding was not applied.
As described above, the wear on the rear surface of the plate piece 3b that has been hardened and welded to the top surface or the like has progressed in the width direction. However, the wear gradually becomes shallower in the width direction, and if the build-up welding for the wear on the rear surface due to the workpiece that wraps around the rear surface has the required length in the width direction, the origin of wear occurs. It has been found that the effect of sufficiently preventing wear can be obtained even if hard welding is not performed in this range over the entire width in the width direction.
Thus, not performing unnecessary build-up welding leads to cost reduction, and the required length in the width direction may be appropriately determined by experiment, actual operation or the like according to the object to be processed.

  As a specific configuration of the present invention, an axial rotation shaft is provided in a bowl-shaped casing, and a rectangular plate-shaped paddle protruding in the radial direction is provided on the outer peripheral surface of the rotation shaft. In a rotary processing machine that is provided with an inclination relative to the rotary shaft and is mixed while being fed in one direction with a paddle by rotating the rotary shaft, the rotary shaft projects and rotates in the radial direction from the outer peripheral surface of the rotary shaft of the paddle Hardened and welded over the entire top surface of the rectangular plate base material whose width direction is inclined with respect to the axial direction, and the top end of the rectangular plate base material on the front end surface in the paddle rotation direction and the front surface in the same rotation direction Hardened and welded over the entire length of the required length in the protruding direction from the edge toward the inside in the protruding direction, and the rear surface in the same direction of rotation is directed inward in the width direction from the required length in the protruding direction and the end edge of the front end surface in the rotating direction. Width direction Strain facilities cured overlay clad in portions throughout that enters each length, it is possible to adopt a configuration provided with the projecting direction required length range in a portion not subjected to hardening overlay clad of the rotation direction rear.

In this configuration, for example, the paddles of both rotating shafts that rotate reversely as in the case of a biaxial rotating processor have their circumferential inclinations reversed with respect to the respective rotating shafts (if one is inclined to the right, the other Is tilted to the left).
For this reason, on the rear end surface in the rotation direction of the base material, the build-up welding is performed over the entire length in the same protrusion direction as the rotation direction front end surface from the top surface edge toward the inside in the protrusion direction, and the above Also on the rear side in the rotational direction, on the rear side in the projecting direction from the top surface edge, which is the same size as the hardfacing welding of the entire area entering the inner side from the top surface edge and the front end surface edge in the rotational direction. If the hardened overlay is applied to the entire area where the required length in the protruding direction and the required length in the width direction from the end edge on the rear side in the rotational direction toward the inner side in the width direction are applied (the same mode on the front and rear sides in the same direction in the same direction) When the build-up welding is performed), even if the inclination is reversed, the build-up welded portion has the same mounting mode, so that it is not necessary to consider the mounting mode and the paddle mounting operation becomes smooth.

  Further, in the portion where the hard build-up welding is not performed, if hard build-up welding is performed over the entire length in the projecting direction from the top surface edge toward the inside in the projecting direction, the covering that goes from the top surface to the rear surface is performed. Abrasion due to the processed material can be effectively prevented. This required length in the protruding direction may be determined appropriately by experiment, actual operation, etc. according to the object to be processed.

Furthermore, with respect to the required length in the protruding direction on the inner side from the top surface edge of the hardfacing weld on the front side in the rotational direction, the required length in the protruding direction on the inner side from the top surface edge of the hardened weld on the rear surface is set. Can be shortened.
As described above, on the front and rear surfaces in the rotation direction of the base material, the front surface is severely worn against the rear surface. For this reason, even if the hardfacing weld on the rear surface is shortened inward from the hardfacing welding on the front surface, the life of the paddle can be reduced without affecting the life of the paddle. Become. The degree of shortening may be appropriately determined by experiment, actual operation, etc. according to the object to be processed.

  If the hard welded paddle becomes worn and can no longer be used, the entire paddle may be replaced. However, most of the welded welds are usually left without wear. For this reason, the base metal piece of the remaining hardfacing welded portion that has not been excised from the base metal piece corresponding to the excised part is excised leaving a hardened welded part that can use the base material that can no longer be used. And can be recycled by welding (see FIG. 6). Compared to hard overlay welding, the welding of the two base metal pieces is easy and advantageous in terms of cost.

  In the present invention, since the portion of the hardfacing weld is specified as described above, the life of the paddle can be improved while suppressing the cost. If the life of the paddle is extended, it will be possible to operate the rotary processor continuously, improve the processing capacity of mixing, kneading, crushing, pulverization, etc. and maintain the same capacity for a long time, and reduce the paddle replacement work. There are advantages such as cost reduction and shortening of downtime of equipment equipped with a rotary processor.

1 shows an embodiment of a rotary processing machine according to the present invention, in which (a) is a cutaway side view, (b) is a partially enlarged perspective view from the left side of the left rotation shaft of (a). The paddle of the embodiment is shown, (a) is a front view, (b) is a plan view, (c) is a bottom view, (d) is a left side view, and (e) is a rear view. The other example of the paddle of the embodiment is shown, (a) is a front view, (b) is a plan view, (c) is a bottom view, (d) is a left side view, and (e) is a rear view. The other example of the paddle of the embodiment is shown, (a) is a front view, (b) is a plan view, (c) is a bottom view, (d) is a left side view, and (e) is a rear view. The other example of the paddle of the embodiment is shown, (a) is a front view, (b) is a plan view, (c) is a bottom view, (d) is a left side view, and (e) is a rear view. Explanatory drawing of repair method for the paddle Perspective view of conventional paddle part

  One embodiment of the rotary processor according to the present invention is shown in FIG. 1 and FIG. 2, and this embodiment is a pug mill related to pellet production using powdered ore or the like. Also in this embodiment, as in the prior art, a cylindrical rotating shaft 2 in the axial direction is provided in a bowl-shaped casing 1, and a rectangular plate-shaped paddle 10 protruding in the radial direction is provided on the outer peripheral surface of the rotating shaft 2. The direction (left and right direction in FIG. 2A) is inclined with respect to the circumferential direction of the rotating shaft 2 (see FIG. 1B), and the workpiece to be processed put into the casing 1 by the rotation of the rotating shaft 2 is The paddle 10 is mixed (kneaded) while being sent out in one direction. Since this embodiment is biaxial, the paddle 10 of one rotating shaft 2 is inclined to the right with respect to the circumferential direction, and the paddle 10 of the other rotating shaft 2 is inclined to the left. In the figure, 1 a is a lid of the casing 1.

  The above configuration is the same as the conventional one, and the present invention is characterized by the configuration of the paddle 10. In the paddle 10, a rectangular plate-shaped plate piece (base material) 12 is fastened by a bolt 13 to a mounting piece 11 that is welded and protruded to the outer peripheral surface of the rotary shaft 2, and a hardened build-up is applied to a required portion of the plate piece 12. A weld 14 is applied (see FIG. 1B). Although this hardening build-up welding 14 may be performed after the plate piece 12 is fastened to the mounting piece 11, it is generally performed before the mounting. The attachment piece 11 protrudes in the radial direction from the outer peripheral surface of the rotating shaft 2, and the width direction is inclined with respect to the circumferential direction of the rotating shaft 2. For this reason, the plate piece 12 fastened to the mounting piece 11 similarly protrudes in the radial direction from the outer peripheral surface of the rotating shaft 2, and the width direction thereof is inclined with respect to the circumferential direction of the rotating shaft 2. Become. In the figure, 13a is a bolt insertion hole.

As shown in FIG. 2, the cured build-up weld 14 has a protrusion direction required length L ₁ extending inwardly from the top surface edge on the top surface in the protruding direction of the plate piece 12, its front and rear surfaces, and both end surfaces. L ₃ or width direction required length _{L 2} is subjected, respectively (top overlay clad: 14a, the front overlay clad: 14b, rear overlay clad: 14c, 14c ', opposite end surfaces overlay clad: 14d, 14d). At this time, the rear surface build-up welds 14c and 14c ′ are applied only from the respective end edges of the both side end surfaces or the top surface to the insides of the required lengths L ₂ and L ₃ and the regions surrounded by them. Is a portion 12c that is not subjected to hard overlay welding. That is, provided a portion 12c which is not subjected to hardening overlay clad in a range in the projecting direction required length L ₁ from the top surface edge toward the protruding inward in the rotational direction b rear of the plate piece 12 (the rear surface of the feed direction a) ing.
The plate piece 12 uses a rolled material for general structure of SS400, and the hardfacing weld 14 is welded by using WC (tungsten carbide) dispersedly bonded to a high carbon (C) high chromium (Cr) material. did. The hardness Hv of the cured build-up weld 14 was 600 or more.

The required lengths L ₁ and L _{3 in} the protruding direction from the top surface edge to the inside or the required length L _{2 in the} width direction may be appropriately determined by experiments, actual operations, or the like. For example, when the horizontal width of the plate piece 12 is 110 mm, the vertical width is 125 mm, and the thickness is 12 mm, the build-up weld thickness is 5 mm, and L _{1 is} 50 mm, L _{2 is} 25 mm, and L _{3 is} 15 mm. Under the same conditions as the paddle 3 in FIG. 7, the wear hole did not occur even after 4 months, and smooth feeding and mixing operations could be performed.

Further, since the provide the hardened buildup welding 14c of L ₂ (the width direction required length from the overlay clad 14d edge of the end face to the inside) width in presence end after plate piece 12, the paddles 10 At the time of rotation, the object to be treated is also caught on the rear surface, but it has been confirmed that the occurrence of wear due to the object to be treated is effectively prevented by the cured build-up weld 14c at the front side end of the rear surface.
At this time, the boundary with the hard build-up weld 14c on the front rear surface in the rotational direction of the paddle (if the paddle 10 on the left rotating shaft 2 in FIG. 1 (a) is the right hard build-up weld 14c in FIG. 2 (e)) In the portion 12c that is not overlaid, the object to be treated stays due to the level difference and is self-lifted, and due to the presence of the layer, there is almost no wear on the rear side (left side in FIG. 2 (e)). I couldn't. From this, it was confirmed that the cured build-up welding 14c may be halfway in the width direction of the plate piece 12. In other words, it was confirmed that there was no problem even if the portion 12c that was not subjected to hard overlay welding was provided.

The above test results are equivalent to the case where the same hard welding 14b as the front surface (surface of FIG. 2A) is applied to the rear surface (surface of FIG. 2E) of the plate piece 12 in the rotational direction. From this, L ₁ is 50/125 to 40% or more of the vertical width, L ₂ is 25/110 to 23% or more of the horizontal width, and L ₃ is 15/110 to 14% of the horizontal width. It can be understood that the above is sufficient.

Further, if it is permitted in terms of cost, on the rear surface of the plate piece 12, hardening build-up welding is performed so that the boundary between the portion of the hardening build-up weld 14 c and the plate piece 12 that is not welded is a flat surface. Hardened build-up weld 14 may also be applied to unexposed portion 12c (the back face may also be hardened welded 14 over the entire width in the same manner as the front face), but the rear face is hardened as shown. The build-up weld 14c has a length (width) shorter than that of the front face 14b (L ₃ <L ₁ ). For this reason, the area | region of the hardening build-up welding 14c is reducing, and cost reduction is aimed at.

  In the present embodiment, since the hardened welds 14d and 14c having the same size are also provided on both end surfaces and both sides of the rear surface of the plate piece 12, the paddles 10 and 10 of the rotary shafts 2 and 2 of this embodiment are provided. In the width direction, one is inclined to the right with respect to the circumferential direction of each rotating shaft 2, and the other is inclined to the left. In both inclined states, the hardfacing welded portion 14 (14a, 14b, 14c, 14c ' 14d) is the same mounting mode. For this reason, it is not necessary to consider the mounting mode, and the paddle mounting operation is smooth.

Since the paddle 10 has a high wear resistance in the portion where the hardfacing weld 14 is applied, the exposed surface which is not hardened and welded is eventually worn out and often cannot be used. In this case, the whole plate piece 12 may be removed from the attachment piece 11 and replaced with a plate piece 12 provided with a new hardened weld 14.
However, as shown in FIG. 6, the plate piece 12 that has become unusable is excised by plasma cutting or the like, leaving the hardened weld 14 portion (FIG. 6A), and the plate piece 12a corresponding to the excised portion. Can be regenerated by welding and joining to the remaining hard-welded welded plate piece 12 ′ (FIG. 5B). Compared with the hard welding 14, the welded joint 15 is easy and advantageous in terms of cost.
At this time, if the required length L _{1 and the} like are appropriately determined by comparing the work cost of the welded joint 15 with the work costs of the cured build-up weld 14 to the required lengths L ₁ , L ₂ , and L _3. good.

The plate piece 12 may be made of general structural rolled steel other than SS400, for example, SS330, SS490, SS540, and wear-resistant cast iron such as high chromium cast iron.
Various welding methods, such as covering arc welding, carbon dioxide arc welding, and plasma powder welding, can be used for the hardening build-up welding 14. In such welding, it is desirable to form a composite structure in which tungsten carbide powder particles are added and dispersed at a rate of 20 to 40% by weight into the matrix melt pool while welding the wires forming the matrix. is there. In addition, as a filler material for forming the super-hardened weld 14 in place of the addition of tungsten carbide, it includes C: 4.5 to 6.0% by weight and Cr: 20.0 to 30.0%. In addition, a multicomponent carbide precipitation hardening type containing one or more of Mo, Nb, V, and B, consisting of the remaining Fe and impurities, and having Hv: 900 or more can be applied.
Furthermore, as an example of the chemical component of the weld metal, C (4-5 wt%), Si (0.4-1.2 wt%), Mn (1.8-2.5 wt%), Cr (about 25 % By weight) and Fe (remainder). Ni may be used instead of Fe. At this time, in the plasma powder welding, tungsten carbide may be mixed into metal powder such as Fe, Ni, and Cr.

Depending on the hardness of the workpiece, as shown in FIG. 3, at least one of the required lengths L ₁ , L ₂ , L ₃ may be shorter than the above length (L ₁ ′ <L ₁ , L ₂ ′). <L ₂ , L ₃ ′ <L ₃ ), as shown in FIG. 4, shortening only the build-up weld 14 c on the rear rear surface in the rotational direction (L ₁ ′ <L ₁ ), as shown in FIG. Even if the overlay welding 14c on the rear side in the rotational direction is omitted, the operational effects of the present invention can be exhibited. In FIG. 5, the build-up welding 14d on the rear end face in the rotation direction can also be omitted.
4 and FIG. 5 shows the paddle 10 of the right rotation shaft 2 in FIG. For this reason, the paddle 10 of the left rotation shaft 2 is in the form of a hard weld 14 whose back is symmetrical with respect to FIGS. 4 and 5.

The pug mill of the above embodiment was a case of two axes, but the present invention can be adopted even in the case of one axis or three axes or more, and the rotary processing machine according to the present invention is not limited to the above-described pellet manufacturing, Effective for processing that requires wear resistance such as sintering, coke, coal, cement, asphalt, ceramic, ore, crushed stone, etc., such as mixers, kneaders, granulators, crushers, crushers, etc. Of course, various machines for rotating the workpiece are included. At this time, it goes without saying that the blades that perform stirring and the like of these machines also correspond to the paddle of the present invention.

1 casing 2 rotating shaft 3 and 10 paddles 3a, 11 plate piece of the mounting piece 3b, 12 paddle plate piece 13 mounting bolt 14,14a, 14b, 14c, 14d cured overlay clad _{L 1, L 3, L 1} ' , L ₃ ′ Required length L _{2 in} the hardening build-up weld 14, L ₂ ′ Required length in the width direction of the build-up weld 14

Claims (4)

An axial rotation shaft (2) is provided in the bowl-shaped casing (1), and a rectangular plate-shaped paddle (10) projecting in the radial direction on the outer peripheral surface of the rotation shaft (2) is rotated in the width direction. The rotary processing machine is provided to be inclined with respect to the circumferential direction, and mixes while feeding the object to be processed put into the casing (1) by the rotation of the rotating shaft (2) in one direction with the paddle (10). Paddle (10)
Hardened welding (14a) is applied to the entire top surface of the rectangular plate-like base material (12) protruding in the radial direction from the outer peripheral surface of the rotary shaft and inclined in the width direction with respect to the peripheral direction of the rotary shaft. The required length (L ₁₎ in the projecting direction toward the inside in the projecting direction projecting in the radial direction from the edge of the top surface on the front end surface in the rotational direction and the front surface in the rotational direction of the paddle (10) of the shaped base material (12). ) Hardened welding (14b, 14d) is applied to the entire region, and the rear surface in the same rotational direction is inward in the width direction from the required length in the protruding direction (L ₁ , L ₁ ′) and the end edge on the front end surface in the rotational direction. Hardened welding (14c) is applied to the entire area where the required length in the width direction (L ₂ , L ₂ ′) has entered, and the required length in the protruding direction (L ₁ , L ₁ ′) on the rear surface in the rotational direction. ) (12c) where hardened weld is not applied Rotation processing machine paddle, characterized in that provision. Hardening welding (14d) over the entire length in the projecting direction (L ₁ , L ₁ ′) of the rear end surface in the rotational direction is the same as the front end surface in the rotational direction from the top surface edge toward the inside in the projecting direction. The top surface having the same size as that of the hardfacing weld (14c) of the entire region that has entered the inside from the top surface edge and the rotation direction front end surface edge on the rear rear surface in the rotational direction. Required length (L ₁ , L ₁ ′) in the protruding direction from the edge toward the inside in the protruding direction and required length (L ₂ , L _{2 in the} width direction from the edge on the rear end surface in the rotation direction toward the inner side in the width direction) ') The paddle for a rotary processing machine according to claim 1, wherein the build-up welding (14c) is performed on the entire area of each part. In part (12c) not subjected to the curing overlay clad, subjected protruding direction required length inward from the top surface edge (L _3, L 3 ') curing the overlay clad the entire (14c' a) The paddle for a rotary processor according to claim 1 or 2, wherein   The method of repairing a paddle (10) according to any one of claims 1 to 3, wherein the base material (12) is excised leaving its hardened welded part (14), and the excised part Repairing a paddle for a rotary processor, wherein the base material piece (12a) corresponding to the above-mentioned is welded and regenerated to the base material piece (12 ') of the remaining hardened welded portion (14) which has been cut off Method.

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