JPS6038043A - Crushing apparatus - 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 This relates to a pulverizing device that crushes powder into powder, and in particular, the pulverizing device 59. The present invention relates to a crushing device whose rings can be easily replaced.

For example, in thermal power plants, cement L plants, etc., crushing devices such as meniball mills and roller mills are used to crush coal and cement raw materials into fine powder.

FIG. 1 is a partially sectional perspective view of a ball mill for crushing coal used in a coal-fired power plant.

For example, in a ball mill, as shown in Fig. 1, coal feed pipe 2
09 Coal crushing section 30. Power transmission section 40° classifier 50. Pulverized coal outlet pipe 60. It is composed of a foreign matter discharge lower 0 and a conveying air port 80.

The coal is placed in the mill housing 10 as shown by arrow A in FIG.
Coal powder is supplied to the inside of the one-volume portion 30 as shown by arrow B from the second part of the coal feed pipe 20 located in the center of the coal powder.

The coal crushing section 30 includes a fixedly rotating lower crushing ring 31 connected to a power transmission section 40, and a fixed upper crushing ring 31 pressurized by a spring or a nitrogen (N2) gas compression cylinder 33. It is composed of a ring 34.

The supplied coal indicated by the arrow B mentioned above is pulverized by the lower crushing ring 31 and the ball 32 in the crushing section 30, and is discharged to the outside of the crushing section 30 as indicated by the arrow C.

This pulverized coal is transported to the mill housing 10 as shown by the arrow by the conveying air from the conveying air port 80.
The inside of the liquid is blown up and fed into the classifier 50 as shown by arrow E.

The coal sent into the classifier 50 is separated into pulverized coal and coarse pulverized coal, and the pulverized coal is classified into i50 as shown by arrow F.
The coarse coal is sent from the outlet pipe 60 to the burner section (not shown) through the coarse coal discharge port 51 at the bottom of the classifier 50 through specific gravity separation as shown by arrow G, and then to the coal crushing section 30 as shown by arrow B. It is recycled inward and re-ground into pulverized coal.

It should be noted that foreign objects (byrite) such as metals and rocks contained in the coal are not crushed even if they pass through the coal crushing section 3o, so they fall out of the mill housing 1o through the foreign object discharge/1-)D 70. Separated and discharged.

Ball mills such as those described above are used, and this type of ball mill has excellent pulverization performance, consumes less power than mills such as tube mills and roller mills, and has a separate crushing section 3o and rotating section 9o. Because of this, there is an advantage that coal particles do not get stuck in the rotating part 9 degrees, making it easy to maintain and manage the equipment, but it also has the disadvantage of large vibrations.

On the other hand, a roller mill is constructed as shown in the perspective view of FIG. 3, and is different from the ball mill shown in FIG. As shown in FIG. 3, the roller mill has a coal crushing section 3o with a crushing ring 31 and roller
It is composed of 5. Therefore, only the difference in the coal crushing section 3° will be explained.

FIG. 2 is a longitudinal sectional view showing the coal crushing section 3o of the ball mill, and FIG. 4 is a sectional view showing the coal crushing section 30 of the roller mill. Comparatively considering a ball mill and a roller mill, as shown in Fig. 2, the balls 32 placed at the second part of the ring 31 rotate and revolve around the rotation of the ring 31 in the ball mill, whereas in the roller mill, as shown in Fig. 4, The major difference is that the roller 35, which corresponds to a ball, is restricted from orbiting and only rotates on its axis. That is, in a ball mill, since the balls 32 of the number of sides perform irregular revolving motion, mutual collision loads and eccentric loads occur between the balls 32, and the rotating shaft 1. Lower crushing ring 31. The crushing unit 3o, which consists of the balls 32 and the upper crushing ring 34, vibrates at the natural frequency of the yarn, but in a roller mill, the rotational movement of the rollers 35 is restrained, so the above-mentioned impact load does not occur and the vibration is small, but the consumption The disadvantage is that it requires a lot of power.

In this way, the lower crushing ring 33t of the coal crushing section 30 was formed as shown in FIGS. 1, 2, and 3, and the lower crushing ring 31 was formed as follows.

FIG. 2 shows the coal crushing section 30 in detail, and the lower crushing ring 31 transfers the rotational force of the rotating shaft 1 to the lower crushing ring 31.
It is fitted into the yoke 36 in order to transmit the signal and is configured not to move in the radial direction. On the other hand, in order to prevent displacement in the circumferential direction, the two are also engaged by a key 37.

The upper powder p+) ring 34 is also supported by the spider 3 which is a support frame.
8 is also connected by a key 37. ball 3
2 is sandwiched between the upper and lower crushing rings 31 and 34 configured in this way, and the contact portions of these crushing rings 3↓ and 34 that contact the balls 32 have race surfaces 39 so as to come into surface contact with the outer surfaces of the holes 32. The coal is pulverized on this race surface 39, and therefore the race surface 39 and balls 32 are most severely worn.

Figures 5 to 7 are diagrams showing the relationship between 11JJ and wear depth during operation of the ball mill. Figure 5 shows the wear amount of the ring 32, and Figure 7 shows the change over time in the wear amount of the lower grinding ring 31. are shown respectively. As is clear from these FIGS. 5 and 7, wear progresses at a relatively high speed in each part after 6000 hours, and the strength of each part decreases in proportion to this. Therefore, in severe cases, the upper and lower crushing rings 31, 34 and balls 32 must be replaced with new spare parts after approximately 10,000 hours of operation.

To explain the replacement of the upper and lower crushing rings 31, 34 and balls 32 of the coal crushing section 30 using FIG. 1, first, the coal feed pipe 20. The coal feed pipe 60 is removed, and the ceiling plate 11 of the mill housing 10 is also removed. Next, guide vane 5
11 All internal parts of the mill above the coal crushing section 30, such as the hopper 52 of the classifier 50, must be removed.

Furthermore, after replacing the coal crushing section 30, the internal parts of the mill must be assembled in the reverse order as explained above, and the replacement work for each mill requires a long time of 5 to 7 days. There is.

Furthermore, in response to the recent increase in the capacity of boilers, crushing equipment has also become larger. For example, the diameter of each crushing ring 3134 is 4.
m or more, its own weight is 11 tons, the total height of the device is often more than 7 m, and the outer diameter of the ball 33 is close to 1 m, and the weight of each piece is 2.
It amounts to tons.

For this reason, each member is heavy, and it is necessary to install a large-capacity hoist or the like in advance for the replacement work, which further worsens the efficiency of the replacement work.

The roller mill shown in FIG. 3 is an example of a structure in which the coal crushing section 3° can be easily replaced. In this roller mill, a roller 35 is used instead of a ball, and the crushing ring 31 in contact with the roller 35 is provided only on the underside of the roller 35.

When the grinding ring 31 becomes worn out and needs to be replaced, it can be taken out from the roller replacement door (not shown) provided in the mill casing 1o, and inside the mill as in the ball mill shown in FIG. There is no need to disassemble them one by one.

This invention uses a split TFL structure for the crushing ring so that it can be easily replaced in the event of wear and tear.
In addition, the pulverizer is constructed so that wear of the coal S frame can be reduced as much as possible. - In short, in this invention, the grinding ring is formed by an assembly divided into a plurality of segments, and the two segments are engaged at the joints of each segment, and the pressurizing force is approximately equal to that of the adjacent segments at the joints of each segment. The structure is such that there is no difference in level between the segments.

Examples of the present invention will be described below.

8 is a plan view of the lower crushing ring, FIG. 9 is a partially sectional side view of FIG. 8, and FIG. 10 is an inclined view of the coal crushing section 30.

In FIG. 8 to FIG. 1O, numerals 31 to 39 indicate the same parts as the conventional ones.

31a, 31b, 31c, 31d, 31e, 31f indicate segments into which the lower crushing ring 31 of the present invention is divided, and 41a, 41b, 41c, 41d, 41e, 41f
, 41g are each segment 31a and 31b, 31b and 31
c, 310)-:<1s-x]AJ+q1-'l'+
Connection part between +alt-n1+ and 31a, 42a, 4
2b is each segment 31a, 31b, 31c, 31'd
, 31e, 31f connecting portions 41a, 41b, 41.
These are the upper and lower protrusions of c, 41d, 41e, 41f, and 41g.

In such a structure, the lower powder 6 and the ring 31 are
As shown in Figures to Figure 10, segments 31a31b, 3
1c, 31d, 31e, and 31f, and the lower crushing ring 31 has substantially fan-shaped segments) 31a to 31f.
It is formed by arranging a plurality of 31f in a ring shape. The connecting portions in the circumferential direction of each segment) 31a to 31f are 41a to 41g for each adjacent segment) 31
Upper protrusion 42a and lower protrusion 4.2b of a to 31f
By connecting them through engagement, the lower crushing ring 31 is formed into a ring-like shape as a whole.

In this way, by dividing the lower grinding ring 31, which is the most worn, into each segment) 31a to 31f, conventionally, even if a part of the ring is damaged, the entire lower ring 31 can be replaced with a new or spare lower grinding ring. However, according to the present invention, only the worn segments need to be replaced, and the effort required for replacement can be saved accordingly.

FIG. 11 is a perspective view showing the connecting portion of the lower crushing ring. In FIG. 11, the left side of the figure is segment 31f,
Assuming that the right side is 31a, the rotation direction of the lower crushing ring 31 formed by the segments 31f and 31a is clockwise as shown by arrow X in the figure, and the rotation direction of the ball 32 is counterclockwise as shown by arrow Y in the figure. direction.

In this FIG. 11, for convenience of explanation, segment 3
1a is referred to as a preceding segment, and segment 31f is referred to as a subsequent segment.

That is, preceding segment 1 = 31a and subsequent segment) 31
f is connected at the connection part 41g, but the connection is at the first
As shown in FIG. 1, the lower protrusion 4 of the trailing segment 31f
2b, the upper protrusion 42a of the preceding segment 31a
is connected with the Therefore ball 32
is rolling on the race surface 39 of the leading segment 31&, the ball 32. Due to the weight of the preceding segment 31a, the upper protruding part 42a of the preceding segment 31a presses the lower protruding part 42b of the succeeding upper segment 31f, and as a result, the connecting part 41g between the segments 31a and 31f becomes on the same plane and the connection is made. There is no step formed in the portion 41g.

FIGS. 12 and 13 show other embodiments showing how the segments of the lower crushing ring 31 are connected to each other.

The difference between the one in Figure 11 and those in Figures 12 and 13 is that in Figure 11, the preceding segment) 31
In the connection part 41g between a and the succeeding segment 31f, the upper protrusion 42a and the lower protrusion 42b are connected on the same plane, but in the case of '+S12, the connection part 41g is wedge-shaped,
In the one shown in FIG. 13, the connecting portion 41g is formed into an uneven shape for engagement.

That is, FIG. 12 is a side view showing another embodiment, in which the connecting portion 41g of each segment 31a, 31f is formed into a wedge shape, and the upper protruding portion 42a of the preceding segment) 31a.
Since the overlapping portion of the lower protruding portion 42b and the lower protruding portion 42b are inclined, even if the connecting portion 41g is separated from the one shown in FIG. It can be absorbed.

The one in FIG. 13 shows still another embodiment, in which the connecting portions 41g of each segment 31a, 31f are formed in an uneven shape, and the upper protrusion of the preceding segment 31a, 42a and the lower The overlapping portions of the side protrusions 42b have an uneven shape and form the leading segment 31. a and the succeeding segment 31f are engaged by this unevenness, so both segments) 3
There is no misalignment at the connecting portion 41g between 1a and 31f, and thereby there is no difference in level at the connecting portion 41g.

In this way, the lower crushing ring 31 is constituted by an assembly of segments) 31a, ~3]-f divided in the circumferential direction, and this lower crushing ring 31 is attached to the yoke 36 as follows. There is.

FIG. 14 is a longitudinal sectional view showing the connection state between the lower crushing ring 31 and the yoke 36.

Whistle i J-IE! 711. -71ha τ Ast → Lowh
The 1-face and -4 (numbered grooves) of the base 6 are convex portions provided on the lower surface of the lower crushing ring 31.

Segments 31a of the lower crushing ring 31 are attached by the method shown in FIG. 14. In other words, a fitting #+743 is formed for the yoke 36 and a segment) 3
1a is formed with a convex portion 44 that engages with this groove 43, and by engaging both this groove 43 and the convex portion 44, the entire lower crushing ring 31 can be prevented from shifting in the radial direction. .

In the embodiments of the present invention, the lower crushing ring 31 of a ball mill has been described as an example, but the present invention is not limited to the lower crushing ring 31 of a ball mill, and the crushing of a roller mill shown in FIG. 3 and FIG. This can also be applied to the ring 31.

FIG. 15 is a perspective view showing an embodiment of the upper grinding ring of the ball mill.

The one shown in FIG. 15 has the segment 31f31a shown in FIG. 11 attached to the upper crushing ring 34 for one core. ta ≠ 1. As shown in FIG. 15, the upper crushing IJ ring 34 above the ball 32 is connected to the segments 31a and 31f
It is connected to the end portion of the connecting portion 41g.

In FIG. 15, the upper crushing ring 34 is in a stopped state, and the ball 32 rotates clockwise as shown by arrow Y. In contrast to the case in FIG. 11, in FIG. is the leading segment and 3↓a is the trailing segment.

Therefore, the preceding segment 31f and the succeeding segment)3]
, a are opposite to those shown in FIG. 11.

That is, the lower protrusion 42b of the preceding segment) 31f
The upper protrusion 42a of the succeeding segment 31a is placed on top of the segment.

This is done by rotating the ball 32 in the clockwise direction Y to create the preceding segment (31f is the subsequent segment) and press 31a, while the subsequent segment (31a is the preceding segment).
31f will be pushed down by its own weight, and 31f will be pushed down by its own weight.

By pushing up and pushing down 31a, the level difference in the connecting portion 41g disappears.

Note that the connecting portion 41g of the upper crushing ring 34 may be wedge-shaped as shown in FIG. 12, or uneven as shown in FIG. 13.

FIG. 16 is a longitudinal sectional view showing the connection state between the spider 38 and the upper crushing ring 34.

In FIG. 16, 45 is a groove provided on the lower surface of the spider 38, and 46 is a convex portion provided on the upper surface of the upper crushing ring 34.

Segment of upper grinding ring 34 to spider 38) 3
Attachment of 1a is carried out as shown in FIG.

As shown in FIG. 16, @45 is formed on the lower surface of the spider 38, and a convex portion 46 is provided on the upper surface of the segment 31a, and the two are engaged and fixed. This prevents the upper crushing ring 34 from shifting in the radial direction.

FIG. 17 shows a modification of the one shown in FIG. 16, in which a dovetail groove 45 is formed for the spider 38 and a segment)
A convex portion 46 is formed on the protrusion 31a to engage the two. Since the segment 31'a is locked by the engagement between the dovetail groove 45 and the convex portion 46, the segment 31'a will not fall off the spider 38. Note that if the spider is provided with a notch corresponding to the circumference of the segment arc portion on the inside, it can be inserted and installed.

FIG. 18 shows a side view of a combination of the lower crushing ring 31 of FIG. 11 and the upper crushing ring 34 of FIG. 15 applied to a ball mill.

In addition, as mentioned before, the segments 31f and 31a
, 31b for the upper crushing ring 34 and the lower crushing ring 31 may be constructed as shown in FIG. 18.

In other words, the lower crushing ring 31 always places the leading segment on top of the succeeding segment and holds down its 71M portion, and the upper crushing ring 34 holds the leading segment always on top of the leading segment, in other words, its front end in the direction of movement is held. It is preferable that

YK! j, -1-sister mjuku11 -//T'-<4
tT>f&gAq // / / To prevent falling of g*1a, 31f, use the following structure.

In FIG. 18, by determining the total length of each segment 31a', 31f, 31b of the upper powder F4I@34 as follows, each segment 31f, 31a, 31b is supported by at least two grinding balls 32.32. This can prevent the subsequent segments (31a, 31f) from falling. That is, falling is prevented by setting L to L・(D 10w -4-s. Here, D is the outer diameter of the ball 32, W is the maximum gap between the balls 32, 32, and S is the allowable wear 11゛. 1.More specifically, the maximum gap is the gap formed when a predetermined number of balls 32 are arranged in the upper crushing ring 34, and the balls 32 are gathered together in one place so as to be in contact with each other. In other words, it means the maximum gap formed by each ball 32 during transfer.If the length L (chord) of each ball 32 (segment) 31r, 31a, 31b is determined as above, each segment) 31f, 31a, 31
b is always supported at both ends by two or more balls 32, 32, so there is no fear of it falling off.

In this way, although the number of balls 32 varies depending on the capacity of the mill, the length of each segment can be freely selected depending on the number of balls 32.

The table below is an example of segmentation performed by the inventors.

The table below shows an example of the number of segments and segment weight when the crushing rings 31a to 31f according to the present invention are segmented. Segment weight 1.
e T / piece is the weight of one ball 1. It is lighter than a T/piece, and the upper and lower rings are integrated (lo, 8T/piece).
Although it was assumed that the segment would be replaced as is, the weight of the segment (1.6T/piece) is lighter and the size is smaller, so the effort of replacing it can be saved.

In the present invention, by configuring the parts of the crushing section as segments, it is only necessary to replace some parts due to wear or damage, and the effort required for replacement can be saved.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway perspective view showing the overall view of a ball mill for crushing coal, Figure 2 is a longitudinal sectional view of its crushing section, Figure 3 is an overall view of the roller type mill, and Figure 4 is a segmented crushing ring. Fig. 5 is a diagram showing the change in the wear amount of the upper grinding ring over time, Fig. 6 is a line diagram showing the change in the wear amount of the ball over time, and Fig. 7 is a graph showing the change in the wear amount of the lower grinding ring over time. A diagram showing changes over time, FIG. 8 is a plan view showing segmentation of the lower crushing ring, FIG. 9 is a side view of FIG. 8, and FIG. 10 is a perspective view of the crushing section using the segmented ring according to the present invention. A partial view, FIG. 11 is a perspective view showing the joint structure of the lower crushing ring segment of the present invention, FIGS. 12 and 13 are explanatory diagrams of other embodiments of the segment joint structure, and FIG. 14 is the present invention. FIG. 15 is a cross-sectional view showing the joint structure of the upper grinding ring segment, and FIG. 16 is a cross-sectional view showing the joint structure of the upper grinding ring segment and the spider. A sectional view showing,
FIG. 17 is a sectional view showing an embodiment of the method of coupling the upper crushing ring segment and the spider, and FIG. 18 is a partial side view of the upper and lower links. 31... Lower crushing ring 31a, , 31b, 31c, 31d, 31c,
31f-segment 32.35... Rotating body 34... Upper crushing ring 41a, 41b, 4-c, 41d, 41e,
41f - Mountain... Connecting part 42a... Upper protruding part 42b... Lower protruding part Fig. 3 Fig. 5 Fig. 8 Fig. 9 Fig. 10

Claims (1)

[Claims] 1. A device for pulverizing coarse particles into fine powder, comprising a pulverizing ring and a rotating body that performs pulverizing action by moving the powder 6 and the ring 2, wherein the pulverizing ring is rotated in a circular manner. 1. A crushing device comprising an assembly of segments divided into at least two in the circumferential direction. 2. The crushing device according to claim 1, wherein a stepped portion is formed at the connecting portion of the crushing ring segments so that they are placed and engaged with each other. 36. The crushing device according to claim 1 or 2, characterized in that a dovetail groove is formed in the integrally formed spider so as to hold the divided segments.