JPS598782Y2 - Grid screen for screening lumps - Google Patents

Description

[Detailed description of the invention] This invention relates to a lattice screen for screening lumps, and in particular, it is used to classify particles by sieving, that is, to remove and sort out large lumps (on the sieve) mixed in the material to be classified. In other words, I am trying to propose a lattice screen that is particularly useful for rough use.

In order to remove and separate large lumps with a grain size of 50 to 100 mm, so-called grizzly mills, which use steel bars with a wedge-shaped cross section or bars like railroad tracks, have been used to remove and separate large lumps with a grain size of 50 to 100 mm. Since the bar is excessively large, the structure of the vibrating sieve machine must be made strong, and the workability is poor, the noise is significant, the lifespan is short, and it is necessary to replace the bars individually, which increases the number of man-hours. Yes.

Significant noise in vibrating screen machines using common metal screens, including such grizzly screens, can be significantly reduced by the alternative use of rubber screens, i.e., perforated plates or shapes of rubber or rubber-like elastic materials. Rubber screens have come to be widely used in large-scale sieve processing facilities such as steel mills, stone crushing plants, and mines. However, when using a rubber screen for grizzly applications, it was not always possible to expect the desired functionality.

In other words, the wear life, sieving performance, and occurrence of clogging are unsatisfactory.In particular, in order to obtain excellent sieving performance in the grizzly using the metal bar, the direction of the feed flow of the material to be sieved is When the sieve hole is shaped vertically, the wear that starts at the edge of the sieve hole is significant, and as a result, large lumps get stuck in the enlarged sieve hole, and the flat sieve surface causes lumps that should directly enter the sieve hole. This increased clogging frequency impairs sieving performance and requires time and effort for maintenance, inspection, and repair, which is a serious disadvantage, and it was generally considered unusable.

This invention realizes an advantageous solution to the above-mentioned difficulties, and consists of a plurality of ridge-like structures protruding from the sieve surface along the direction of the feed flow of the material to be separated into chunks. It has vertical bars and a plurality of sieve holes that open vertically on the sieve surface with a width approximately equal to the interval between these vertical bars, and the width of the sieve holes protrudes from the side of the vertical bars toward the center of each sieve hole. The sieve is made of a lattice-like structure of rubber or rubber-like elastic material with lateral overhangs that narrow the sieve to a minimum, and the longitudinal bars effectively prevent wear starting at the edge of the sieve hole and its rapid elongation. This prevents the reduction in sieving ability due to the enlargement of the sieves and extends the service life of the lattice screen.In addition, the horizontal overhangs on the sides of the vertical bars minimize the width of the sieve holes, making it possible to prevent large materials from being processed under the sieve. This is to avoid contamination.

In this design, in order to prevent wear on the top surface of the vertical bars and to appropriately guide the turning flow of the processed material that is large enough to cause clogging in the sieves, the top surface of the vertical bars is designed to correspond to the above-mentioned overhang. A vertically raised local ridge-like protrusion is provided to prevent wear and to avoid clogging, and the sieve surface with vertically opened sieve holes is particularly suitable for the sieved material (on the sieve). Since the outflow side is more likely to be exposed to collisions with larger materials to be treated and wear out, the sieve hole openings are biased towards the inflow side of the materials to be treated, and the sieve surface is shaped to have wider edges on the outflow side. In addition, it is desirable in practice to increase the rigidity of the vertical bars or, in addition, to the sieve surfaces that sandwich the sieve holes, by reinforcing cores such as steel bars or flat steel embedded and integrated inside them. .

The specific structure of the lattice screen according to this invention shown in FIGS. 1 and 2 will be explained below with reference to an embodiment.

Reference numeral 1 in the figure is a lattice screen, which is fixedly attached to the side of a vibrating sieve machine (not shown) using the edges 2 and 2 on both sides, and also to the vertical frame at the bottom of the central groove 3 in this example. A large number of them are arranged in parallel in the direction of the supply flow of the material to be sieved, which is indicated by the middle arrow 4.

Although not shown in the drawings, the central groove 3 is filled with a rod-shaped rubber to protect the screw head after the installation.

The lattice screen 1 is prepared as a lattice rectangular body made of rubber or a rubber-like elastic material, and when it is formed, a plurality of vertical ridges protruding from the sieve surface 8 in the direction of the arrow 4 are formed as shown in the figure. A sieve hole 6 that is vertically elongated and opened on the sieve surface 8 with a width approximately equal to the interval between the crosspieces 5 and these vertical crosspieces, and a width of the sieve hole 6 that protrudes from the side surface of the vertical crosspiece 5 toward the center of the sieve hole 6. A lateral overhang 7 is formed to minimize the narrowing of the area.

Therefore, the sieve hole 6 opens vertically and narrowly in the sieve surface 8, which is one step lower than the upper surface of the vertical bar 5, and on the other hand, the sieve hole 6 tapers downward toward the back side of the sieve surface (approx.
゜ or less) shall be held in accordance with customary practice.

As is particularly clear in FIG. 2, the vertical bars 5 have a ridge shape that is raised slightly higher than the sieve surface 8 where the sieve holes 6 open, so that the sieve surface is protected against the flow of large lumps that extend between adjacent vertical bars. 8 from abrasion due to abrasion.

The purpose of the overhang 7 is to suppress as much as possible a long material to be processed that may get mixed in under the sieve since the sieve hole 6 is vertically long, and the purpose of making the sieve hole 6 vertically is to prevent clogging. This is because it is advantageous.

Further, on the upper surface of the vertical crosspiece 5, it is possible to provide a local ridge-like protrusion 9 that is vertically raised in correspondence with each of the overhangs 7, and this protrusion 9 prevents wear that starts at the overhang 7 of the sieve hole 6. It is preferable to form a pedestal shape over the front and back of the overhang 7.

If the inflow side and the outflow side of the processed material on the sieve surface 8 where the sieve holes 6 are vertically opened are called horizontal bars 10 and 11, respectively, and are divided, the width of the lattice screen 1 and the width of the lattice screen 1 will be the width of the horizontal bars 5. , the rear edges are shown as an example, but it is naturally possible to make a modification in which intermediate bars are located between the multiple sieve holes 6 in the direction of the arrow 4, and the front edge or For the inflow side of the processed material shown by arrow 4,
The trailing edge, that is, the outflow side of the coarse processed material (on the sieve),
It is preferable to use a wider edge (larger length in the direction of the arrow) to prevent wear caused by the colliding of the effluent treated material with the rear end of the sieve hole 6. In particular, when using an intermediate crosspiece, it is preferable to use a wider edge (larger length in the direction of the arrow). It is possible to have a length in the direction of the arrow.

As shown in FIG. 4, reinforcing cores 12.13 in the form of steel bars can be buried and integrated inside the vertical bars 5 or the horizontal bars 10.11. For the former, reinforcing core 14 as shown in Fig. 5 in the case of flat steel.
However, it is still possible to combine them by burying them internally.

Width 1800 mm, length 5QQmm as shown and explained above
1800 x 30 by lining up 5 lattice screens vertically
A sieve surface of 00 mm and a thickness of 35 mm is formed, the sieve hole 6 is 120 x 480 mm, and a pair of overhangs 7 are formed.
The vertical bars 5 are arranged to face each other over a distance of 30 mm at intervals of 40 mm.
The adjacent space is 130 mm, the width is 72 mm, and the thickness is 5 Q mm, and a local pedestal-like protrusion 9 is formed over the upper surface 255 mm with a width of 60 mm and a height of 20 mm.The opening ratio is 43.
A test screen weighing 7% and weighing 46 kg/screen was installed at an angle of inclination of 15° and used to remove large coke lumps at a rate of 450 tons per hour.

Here, while the conventional one-piece grizzly has a service life of 1.5 months, the comparative porous rubber screen with square holes of 120 x 120 mm has an improved service life of 5.5 months. The occurrence of clogging was 70% or more, resulting in a significant decrease in sieving performance.
The improved rubber screen that replaced the mm horizontally long holes had a service life of 4 months and a clogging rate of 45%, which was still unsatisfactory.

However, with the above embodiment, a high degree of sieving performance was achieved with less than 30% clogging and less than 10% contamination rate under the +140 mm sieve over a service life of 3 to 4 months or more. When the downward opening taper was set to 3 degrees, high performance with less than 20% clogging was achieved.

Such a dramatic improvement in performance is due to the aspect ratio of 3.2 to 3.2.
I was able to complete the test within the 4.0 range.

In addition, FIG. 6 shows another example in which the width of the sieve hole 6 gradually decreases while reaching the vertically elongated central region, and becomes the minimum width in that region.

As described above, according to this invention, the service life of the grizzly grizzly can be nearly tripled without causing clogging, and the work circulation is significantly improved by reducing noise.

[Brief explanation of the drawing]

Figure 1 is a plan view, Figure 2 is a front view, Figure 3 is a side view, Figures 4 and 5 are sectional views taken along A-A and B-B in Figure 1, respectively, and Figure 6 is a It is an explanatory view showing a modification of a sieve hole. 1... Lattice screen, 4... Direction of supply flow of processed material, 5... Vertical bars, 6...
- Sieve hole, 7... overhang, 9... pedestal-like projection, 10.11... horizontal bar, 12, 13.
14... Reinforcement mind.

Claims (5)

[Scope of utility model registration request] 1. A plurality of vertical bars protrude from the sieve surface in a ridge shape along the direction of the supply flow of the material to be sieved into chunks, and a vertically elongated structure on the sieve surface with a width approximately equal to the spacing between these vertical bars. A lattice-shaped body made of rubber or a rubber-like elastic material having a plurality of sieve holes that open at the center of each sieve hole, and having a horizontal overhang that projects from the side surface of the longitudinal bar toward the center of each sieve hole to minimize the width of the sieve holes. A grid screen for sifting lumps, which is characterized by: 2. The lattice screen according to claim 1, wherein the vertical bars have local ridge-like protrusions vertically raised on the upper surface of the vertical bars corresponding to the extension of the vertical bars. 3. The lattice screen according to claim 1 or 2, in which the vertical bars have a vertical reinforcing core embedded therein. 4. Utility model registration claims 1, 2 or 3, in which a sieve surface with longitudinally opened sieve holes has an opening arrangement of sieve holes that is biased on the inflow side of the material to be sieved with respect to the outflow side of the sieve. 3. The lattice screen described in 3. 5. The lattice screen according to claim 1, 2.3 or 4, wherein the sieve surface has horizontal reinforcing cores embedded and integrated inside the sieve holes.