JPH0642741Y2 - Coal-water slurry production equipment - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a coal-water slurry production apparatus, and more particularly to a coarse slurry flow system of a coarse grain separation strainer at the outlet of a mill.

[Conventional technology]

Slurry fuel can be treated as a fluid by mixing solid particles with a liquid,
It has many advantages in handling and control. For this reason, it has been attracting attention as a new application technology to replace coal bulk handling. However, the slurry at the outlet of the wet tube mill used for slurry production contains coarse-grained components, and it is necessary to remove the coarse-grained components with a strainer in order to make the slurry combustible. However, in the case of a slurry having a large viscosity, it is necessary to have a function of effectively removing the coarse particle component adhering to the filter mesh surface of the strainer and reliably discharging the removed coarse particle component as a coarse slurry flow. FIG. 3 shows a system diagram of a conventional coal-water slurry slurry manufacturing apparatus. The raw coal of the bunker 1 is supplied from the quantitative coal feeder 2 to the wet tube mill 3 to be made into a slurry, and then once retained in the sump tank 4, the coarse grain component in the slurry is separated by the A strainer 6. The slurry from which coarse particles have been removed is once retained in the product tank 7, and then the B strainer 9
Filtered. The combustion slurry that has passed through the filter mesh in the B strainer 9 is transferred to the combustion furnace. On the other hand, the coarse slurry flow separated by the A strainer 6 is directly milled for re-grinding.
Will be transferred to the entrance. The slurry flow separated by the B strainer 9 is transferred to the sump tank 4.

[Problems to be solved by the invention]

As described above, the coarse slurry from the A strainer 6 is fed to the mill 3
It is returned to the entrance of and is pulverized again. In the mill 3, a slurry having a predetermined particle size distribution cannot be obtained unless the material is operated while maintaining the material balance between coal, water and additives. If the amount of the coarse slurry returned to the inside of the mill 3 increases, the above-mentioned material rebalance tends to be broken, and the particle size distribution of the mill outlet slurry becomes unsteady. However, if the amount of coarse slurry returned to the mill 3 is to be kept to a minimum, clogging easily occurs in the coarse slurry discharge portion of the strainer.

The purpose of the present invention is to solve the above-mentioned problems of the prior art,
An object of the present invention is to provide a coal-water slurry manufacturing apparatus capable of maintaining the material balance in the mill and stabilizing the particle size distribution of the mill outlet slurry while preventing clogging of the strainer due to the coarse slurry.

[Means for solving problems]

The above-mentioned purpose is to transfer the slurry containing coarse particles separated by the strainer to the sump tank or the slurry recovery tank,
This is accomplished by circulating a strainer and returning a predetermined amount of slurry in these tanks to the wet mill.

[Action]

The slurry containing coarse particles separated by the strainer is temporarily stored in the sump tank or the slurry recovery tank without being directly returned to the mill, and then circulated through the strainer. Therefore, the coarse slurry flow in the strainer can be increased and clogging in the strainer can be prevented. Since only a predetermined amount of slurry in the sump tank or slurry recovery tank is returned to the mill, the material balance in the mill can be maintained.

[Example of device]

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

FIG. 1 is a system diagram showing a first embodiment of an apparatus for producing a coal-water slurry according to the present invention. 1 is different from the conventional apparatus shown in FIG. 3 in that the crude slurry from the A strainer 6 is collected in a recovery tank 13 via a slurry pump 10, and the slurry in the recovery tank 13 is introduced into the mill 3 inlet. It is to be returned to the sump tank 4. Therefore, the components other than those described above are the same as those in the apparatus shown in FIG. 3, and therefore are denoted by the same reference numerals and detailed description thereof will be omitted.

Next, the operation of the coal-water slurry producing apparatus of the first embodiment having the above-mentioned configuration will be described.

The raw coal of the bunker 1 is supplied from the quantitative coal feeder 2 to the wet tube mill, made into a slurry, temporarily stays in the sump tank 4, and then introduced into the A strainer 6 by the slurry pump 5. In the A strainer 6, the coarse particle components in the slurry are separated, and the slurry from which the coarse particles are removed is retained in the product tank 7 and then introduced into the B strainer 9 by the slurry pump 8 and filtered. The combustion slurry that has passed through the filter screen of the B strainer 9 is transferred to the combustion furnace.

On the other hand, the crude slurry separated by the A strainer 6 is introduced into the recovery tank 13 by the slurry pump 10. Recovery tank 13
Most (constant amount) of the slurry inside is returned to the sump tank 4 by the slurry pump 14, and the rest of the slurry inside the recovery tank 13 is transferred to the mill 3 by the slurry pump 12. The slurry separated by the B strainer 9 is returned to the recovery tank 13 by the slurry pump 11.

Thus, the discharge amount of the sump tank 5, which is the input amount of the A strainer 6, is the total amount of the product slurry amount that has passed through the filter mesh of the A strainer 6 and the amount of crude slurry that has not passed through the filter mesh. . Then, the product slurry in the product tank 7 is supplied to the B strainer 9 by a fixed amount by the slurry pump 8. Therefore, the discharge amount of the slurry pump 8, which is the input amount of the B strainer 9, is the sum of the amount of combustion slurry that has passed through the B strainer 9 filter mesh and the amount of slurry that has not passed through the B strainer 9 filter mesh. Is.

Further, a certain amount of the slurry in the recovery tank 13 is returned to the sump tank 4, and the slurry in the sump tank 4 circulates via the A strainer 6, the product tank 7 and the B strainer 9. Therefore, the circulation does not require the operation of stopping the flow of the coarse slurry to the minimum, and the clogging of the strainer can be avoided. In addition, the filtration net inside the A strainer 6 is 20
Since the mesh in the mesh and B strainer 9 is 30 mesh, the coarse slurry from the A strainer 6 and the B strainer 9
The grain sizes of the coarse grains in the coarse slurries from E. coli differ and the mixed slurries of these coarse slurries have the desired grain size distribution. Next, a part of the slurry in the recovery tank 13 having such a particle size distribution is transferred to the mill 3 and re-ground. Therefore, mill 3
It is possible to keep the multiple balance in the inside constant, and it is possible to suppress the increase of the coarse particle component in the recovery tank 13.

FIG. 2 is a system diagram showing a second embodiment of the coal-water slurry producing apparatus according to the present invention. 2 is different from the conventional device shown in FIG. 3 in that a line for transferring the coarse slurry from the A strainer 6 and the B strainer 9 to the large sump tank 4 is provided and the sump tank 4 is provided.
A line for returning a part of the slurry to the mill 3 is provided. Also in FIG. 2, the same parts as those in FIG. 3 are denoted by the same reference numerals, and the structural description will be omitted.

Next, in the coal-water slurry manufacturing apparatus shown in FIG.
Since the coarse slurry from the A strainer 6 and the B strainer 9 is mixed in the sump tank 4, the slurry in the sump tank 4 can have a desired particle size distribution. Further, since a part of the slurry in the sump tank 4 is returned to the mill 3, the material balance in the mill 3 is maintained and the sump tank 4
It is possible to suppress the increase of coarse particles inside. Particularly in the second embodiment, the first
Compared with the embodiment, one pump for returning the slurry to the mill and the recovery tank 13 are not required, and the device can be simplified.

[Effect of device]

As described above, according to the present invention, since the increase of the amount of coarse slurry from the strainer is allowed, clogging of the strainer is prevented, and only a predetermined amount of the slurry having the desired particle size distribution including the coarse slurry from the strainer is stored in the mill. Since it is returned, by sending a good slurry to the strainer while maintaining the material balance in the mill, stable operation of the strainer and stable quality slurry can be manufactured.

[Brief description of drawings]

FIG. 1 is a system diagram showing a first embodiment of a coal-water slurry production apparatus according to the present invention, and FIG. 2 is a coal according to the present invention-
FIG. 3 is a system diagram showing a second embodiment of a water slurry producing apparatus, and FIG. 3 is a system diagram of a conventional coal-water slurry producing apparatus. 1 ... Bunker, 2 ... Quantitative coal feeder, 3 ... Wet tube mill, 4 ... Sump tank, 6 ... A strainer (20 mesh), 7 ... Product tank, 8 ... B strainer.

Claims (2)

[Scope of utility model registration request] 1. A coal equipped with a sump tank and a strainer for separating coarse particles in the slurry downstream of the slurry in the wet mill.
In the water slurry manufacturing apparatus, a coarse line slurry separated by the strainer is provided with a circulation line for circulating the coarse grain slurry through the sump tank or the slurry recovery tank provided for coarse grain slurry recovery to the strainer, and further in these tanks. And a line for returning a predetermined amount of slurry to the wet mill. 2. The strainer comprises two strainers each having a different mesh degree of a filter mesh installed inside the strainer, and the crude slurry from these two strainers is collected in the sump tank or the slurry. The apparatus for producing a coal-water slurry according to claim (1), characterized in that it is transferred to a tank.