JPH0423585B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for cleaning a vibrating sieve used for separating coarse particles in a highly concentrated coal/water slurry.

[Conventional technology] Highly concentrated coal/water slurry (hereinafter referred to as “CWM”)
It is written as ) is a mixture of finely ground coal and water with a coal concentration of 60% by weight or more, with some additives added.
It is a fuel that can be directly combusted, and in order to satisfy its flammability, transportability, and storage properties, it is required to reduce the content of coarse particles of 150 μm or more.
To remove coarse particles from CWM, a wet sieving method using a vibrating sieve is usually used.

The wet sieving method described above supplies high-concentration CWM to the upper end of an inclined vibrating sieve and applies high-velocity vibration with small amplitude in a plane perpendicular to the sieve surface, thereby preventing the high-concentration CWM from jumping or sliding. The process is repeated while moving down the sieve surface, and the high concentration coarse particles are separated into high-concentration coarse CWM, which is a product on the sieve, and desired high-concentration fine CWM, which is a product under the sieve.
CWM is discharged from the bottom end of the vibrating sieve.

However, in the above-mentioned wet sieving method, the opening of the sieve is minute, so high concentrations that exhibit high viscosity are
When CWM moves on the sieve surface, it attaches to the sieve surface,
As this progresses, the openings of the sieve meshes decrease and eventually become blocked, making it impossible to separate coarse particles from the highly concentrated CWM. Therefore, a method of cleaning the sieve meshes is carried out by simultaneously spraying from above the sieve surface to the entire sieve surface periodically or as needed.

[Problems to be Solved by the Invention] However, according to the above conventional cleaning method,
There is a problem that the cleaning effect is not improved even though a large amount of cleaning water is used.

This is thought to be because the flow of the coarse CWM diluted and washed above the sieve surface is blocked by the washing water sprayed below.

Therefore, the present invention has developed a high-concentration solution that can achieve a large cleaning effect with a relatively small amount of cleaning water.
The present invention attempts to provide a method for cleaning a vibrating screen for CWM.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides high concentration
A method of cleaning the sieve mesh of a vibrating sieve that has become clogged due to CWM wet sieving by spraying cleaning water locally from above the sieve surface sequentially from the top to the bottom of the sieve surface. It is.

[Function] According to the above means, the coarse CWM that has been washed and diluted by the washing water that is sequentially locally sprayed from the top to the bottom of the sieve surface adheres to the sieve surface below the washed part. It flows down over the highly concentrated coarse grain CWM and is discharged from the lower end of the sieve surface to the outside of the machine, and the sieve mesh is washed sequentially from the top to the bottom.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 and FIG. 2 are a side view and a front view showing a schematic configuration of a coarse particle separator used for carrying out the present invention.

In the figure, 1 is a tilted vibrating sieve, vibrating sieve 1
The sieve frame 2 includes a rectangular sieve frame 2, a sieve screen (sieve surface) 3 with a mesh opening of 0.5 to 0.8 mm stretched inside the sieve frame 2, and an oscillator 4 that vibrates the sieve screen 3 at a small amplitude and high frequency. It consists of
The oscillator 4 is attached to the middle upper part of the sieve frame 2 via a mounting base 5 and is connected to the sieve screen 3 via a transmitter 6.

Upper end of vibrating sieve 1 (right end in Figure 1)
Above the sieve screen 3, high-concentration CWM supplied from a wet ball mill or the like is placed in the width direction of the sieve screen 3 (second
A supply gutter 7 is disposed to supply water evenly in the left-right direction in the figure. Further, above the vibrating sieve 1, a plurality of (in FIG. 1, four
The water supply pipes 8a, 8b, 8c, and 8d are arranged at appropriate distances in the vertical direction along the inclination of the vibrating sieve 1, and the water supply pipes 8a, 8b, 8c, and
At 8d, a plurality of water nozzles 9 that spray cleaning water are provided.
a, 9b, 9c, and 9d are attached. The water spray nozzles 9a, 9b, 9c, and 9d are provided so that their full cones during water spraying, indicated by two-dot chain lines in the figure, overlap each other on the sieve surface 3. Each water supply pipe 8a, 8b, 8c, 8d is connected to a solenoid valve 11a, 11b, 11c, 1 which is turned on/off by a timer 10a, 10b, 10c, 10d.
1d to a header 12 which is connected to a source of pressurized water (not shown).

On the other hand, a guide hopper 14 is disposed below the vibrating sieve 1 to guide high-concentration particulate CWM, which is a product under the sieve, to a storage tank 13, and a contamination prevention plate 15 is disposed above the guide hopper 14. ing. The mixing prevention plate 15 prevents the diluted CWM passing through the sieve screen 3 from mixing with the high-concentration fine CWM in the storage tank 13 during water washing of the sieve mesh, and has an upper edge pivotally supported by a shaft 16. The piston rod 18a of the hydraulic cylinder 18 interposed between the back surface and the base 17 expands and contracts to be able to swing between the position shown by the solid line and the position shown by the two-dot chain line in FIG.

Further, on the side of the lower end of the vibrating screen 1, a gutter 20 into which a screw conveyor 19 is inserted is arranged.
High concentration coarse grain CWM and cleaning CWN are placed at the end of the gutter 20.
A switching hopper 23 is provided to switch and guide the sieved product (a mixture of the sieved product and the sieved product during water washing) to the coarse particle collection tank 21 and the drainage pit 22. The switching hopper 23 contains highly concentrated coarse particles.
A CWM discharge port 23a and a cleaning CWM discharge port 23b are provided, and within this switching hopper 23, a switching plate 24 for switching the opening and closing of both discharge ports 23a and 23b is located at the position shown by the solid line in FIG. It is provided so as to be able to swing to the position shown by the dotted chain line.

In addition, the cleaning CWM drained into the drain pit 22
is connected to a wastewater tank (not shown) via pump 26.
It is sent to. Also, in Figure 2, 25
is a bellows interposed between the sieve frame 2 of the vibrating sieve 1 and the upper end of the guide hopper 14.

In the coarse particle separator having the above configuration, the contamination prevention plate 15 and the switching plate 24 are swung to the positions shown by the two-dot chain lines, and the high concentration
When CWM is supplied to the vibrating sieve 1, the high concentration CWM is
Highly concentrated coarse grains, which are sieved products, are sieved while descending the sieve surface 3 while repeating jumping and sliding.
It is separated into CWM and highly concentrated fine CWM, which is a subsieve product. The highly concentrated coarse grain CWM falls into the gutter 20 from the discharge port 2a provided at the lower end of the sieve frame 2 of the vibrating sieve 1, is carried by the screw conveyor 19, falls into the switching hopper 23, and then While the high concentration coarse particle CWM is stored in the coarse particle collection tank 21 through the high concentration coarse particle CWM discharge port 23a, the high concentration fine particle CWM
is stored in the storage tank 13 via the guide hopper 14.

If the sieve screen 3 of the vibrating sieve 1 becomes clogged due to the wet sieving, the supply of high concentration CWM from the supply gutter 7 is stopped, and the contamination prevention plate 15
Then, the switching plate 24 is swung to the position shown by the solid line. Next, the solenoid valve 11a is activated by the timer 10a, and the cleaning water is sent from the header 12 to the uppermost water supply pipe 8a, and the cleaning water is spouted from each water spray nozzle 9a of the water supply pipe 8a for the required time (for example, about 15 seconds). .
Next, each water nozzle 9a of the uppermost water supply pipe 8a
The solenoid valve 11b is activated by the timer 10b, and the cleaning water is spouted from each water nozzle 9b of the second stage water supply pipe 8b for the same period of time, and then stopped. Thereafter, cleaning water is sequentially spouted for the same period of time from the water spray nozzles 9c and 9d of the third and lowest water supply pipes 8c and 8d. The above cleaning is performed while the oscillator 4 is activated and the sieve screen 3 is vibrated.

Due to the stepwise water sprinkling from the water nozzles 9a, 9b, 9c, and 9d of the water supply pipes 8a, 8b, 8c, and 8d in the above-mentioned stages, the viscosity of the highly concentrated coarse particles CWM adhering to the sieve surface decreased. The resulting products are coarse CWM (upper sieve product) and diluted CWM (lower sieve product), and the coarse CWM flows down onto the highly concentrated coarse CWM that adheres to the sieve surface below the washed part and is discharged. While falling into the gutter 20 from the outlet 2a, the diluted
The CWM flows down on the mixing prevention plate 15 and similarly falls into the gutter 20. Coarse particles that fell into the gutter 20
CWM and diluted CWM become cleaning CWM and gutter 2
The water falls into the switching hopper 23 from the end of the cleaning CWM, and is discharged from the cleaning CWM outlet 23b into the drainage pit 22 by the switching plate 24, and is sent to the waste water tank by the pump 25.

Therefore, the sieve mesh of the vibrating sieve 1 is sequentially and locally (stepwise) washed from the top to the bottom in a short time with a relatively small amount of washing water.

In the above embodiment, in order to locally spray washing water from the upper part of the sieve surface to the lower part of the sieve surface to clean the sieve meshes, a plurality of water spray nozzles 9a, 9b, 9c, 9d are used. Although a plurality of water supply pipes 8a, 8b, 8c, and 8d having water spray nozzles are arranged above the sieve surface, a single water supply pipe in the width direction having a plurality of water nozzles is provided so as to be movable up and down along the sieve surface. The water supply pipe may be moved and cleaned intermittently.

[Effects of the Invention] As described above, according to the present invention, coarse CWM washed and diluted by washing water sequentially and locally sprayed from the upper part to the lower part of the sieve surface is removed from the sieve below the washing part. The highly concentrated coarse particles CWM that adheres to the surface flow down and are discharged from the lower end of the sieve surface to the outside of the machine, and the sieve mesh is washed sequentially from the top to the bottom, so coarse particles are The flow of CWM is not obstructed, and the sieve mesh can be cleaned in a short time with a relatively small amount of cleaning water, greatly improving the cleaning effect.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are a side view and a front view, respectively, showing the schematic configuration of a coarse particle separator used for carrying out the present invention. 1... Vibrating sieve, 3... Sieve mesh (sieve mesh), 4... Oscillator,
6...Transmitter, 7...Supply gutter, 8a, 8b, 8c, 8
d... Water supply pipe, 9a, 9b, 9c, 9d... Water nozzle, 10a, 10b, 10c, 10d... Timer, 11a, 11b, 11c, 11d... Solenoid valve,
12...Hetsuda.

Claims (1)

[Claims] 1. When cleaning the sieve mesh of a vibrating sieve that has become clogged due to wet sieving of highly concentrated coal/water slurry,
A method for cleaning a vibrating sieve for highly concentrated coal/water slurry, characterized in that washing water is sequentially locally sprayed from above the sieve surface to clean the sieve meshes from the top to the bottom of the sieve surface.