JPH0144608B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is applicable to, for example, unloading of coal from a coal carrier, which is commonly referred to as "coal unloading, coal storage, and coal transportation" at a coal-fired power plant, storage in a stockyard, and handling within the premises. The present invention relates to a method and apparatus for lifting coarse particles suitable for use in the field.

Conventionally, at coal-fired power plants, coal carriers that have transported coal in bulk are docked alongside the dedicated quay of the coal-fired power plant, and the coal is unloaded from the hatch by cranes and grab buckets, and from there it is transported to reclaimers, belt conveyors, etc. It is then transported to a crusher where it is crushed and blown into a boiler.

However, this method not only requires a large amount of money to construct a dedicated quay, dredging the quay and the channel, and constructing a breakwater, but also causes destruction of the natural environment of the coastline and sea surface (undersea), which is detrimental to the conservation of nature. There is a problem with this.

Furthermore, not only is there a risk of spontaneous combustion of coal during open storage, but also coal dust is generated at all stages of coal unloading, coal storage, and coal transportation, which has become a major pollution problem.

Furthermore, Japan is facing the need to construct a large number of coal-fired power plants based on the assumption that coal will be imported from overseas in the future, but using the conventional methods mentioned above, construction is only possible at a limited number of locations. , there is an urgent need to take measures against this.

The present invention eliminates the above-mentioned drawbacks and proposes a method for unloading and transporting coarse particles such as coal without causing natural destruction and at low cost, and an apparatus that can be directly used in carrying out the method. be.

That is, in the present invention, coarse particles transported by sea to the shore in bulk by a carrier ship are mixed and stirred with water sent from land in the same carrier ship to form a slurry, and the slurry is transported to the shore. After transporting
Separate into water containing coarse particles and fine particles, and then
A method for unloading coarse granules, which is characterized by storing coarse granules in a storage tank, storing water containing fine particles in a sedimentation tank, and further taking out the fine particles precipitated in the sedimentation tank and dewatering them. , and devices directly used to implement this method include a means for supplying water from land into a marine carrier, a means for mixing and agitating coarse particles and water in the carrier to form a slurry; A means for transporting the slurry on land within a pipe, a means for separating the slurry on land into water containing coarse particles and fine particles, a storage tank for storing the coarse particles separated by the same separation means, and a storage tank for storing the coarse particles separated by the same separation means. The present invention relates to a coarse granular material lifting device characterized by having means for storing water containing fine particles in a sedimentation tank, and means for taking out the fine particles from the sedimentation tank and dehydrating them.

Conventionally, when importing coarse granular materials such as coal from overseas, ships tend to be large in order to reduce sea transportation costs, but according to the present invention, it is possible to import coarse granular materials such as coal. Water is pumped from land into the hold of a carrier ship loaded with water, mixed with water to form a slurry, and the slurry is transported to land within the jurisdiction, so a large quay is required for large ships to dock. In addition, there is no need for dredging work to secure water depth in front of the quay, and there is no need to monopolize a wide area of the coastline, and it is only necessary to perform construction on the coastline at the entrance and exit of the slurry transport pipe.
Other coastlines can be preserved in their natural state.

Further, according to the present invention, since the object to be transported is transported in the form of a slurry mixed with water, scattering of dust during transport can be prevented. In addition, by separating the fine powder contained in the transported material with water and dehydrating the fine powder separately from coarse particles with a relatively large diameter,
The dehydration process is extremely efficient;
Particularly in the case of unloading coal used as fuel for power plants, etc., the slurry unloaded coal can be efficiently supplied to the boiler.

Furthermore, in the present invention, before storing the landed slurry, it is separated into coarse particles and water containing fine particles, and the dehydrated coarse particles are charged into the storage tank. No water pressure is applied, so there is no need for the storage to have a strong structure. Furthermore, since the slurry is no longer raised to the top of the storage tank, the lift of the slurry transport pump can be reduced.

Next, an embodiment of the method and apparatus of the present invention will be described based on the drawings.

This example shows the case of unloading thermal coal for power generation. Specifically, for example, it is a case of coarse bituminous coal containing a small amount of fine powder, and the particle size distribution is, for example, a maximum diameter of 50 mm, 3 mm or less. 30%, 0.5mm or less5
%, etc.

FIG. 1 shows a portion for unloading coal in this embodiment, and FIG. 2 shows a portion for supplying the landed coal to a boiler. In the figure, 1 is a coal carrier that has reached near the coastline 3, 2 is a single-point mooring buoy installed on the sea surface near a coal-fired power plant 4 built on land, and 5 and 6 are moored buoys located inside the thermal power plant 4. The coal storage silos and settling basins 7 and 8 are first and second dewatering devices. 9a, 9b, 9c, 9
d is a belt conveyor, and 10 is a pulverized coal-fired boiler building 10.

Inside the coal-fired power plant, there are an ash dump, a generator building, a chimney, a quay for small ships, etc., but these are not shown.

Coal is loaded into the ship's hold 11 through a hatch by a ship loader or the like at the shipping location. Although the ship used is a coal carrier equipped with slurry unloading equipment, the conditions of the coal during marine transport are no different from those during normal coal transport.

The coal carrier 1 is moored to a single-point mooring buoy 2 installed offshore of a coal-fired power plant 4, and the coal carrier 1 and the single-point mooring buoy 2 are connected by hoses 24, 25. Next, fresh water is supplied from the sedimentation pond 6 on land to the fresh water tank 12 of the ship through the fresh water supply pump 23, the submarine piping 22 for fresh water, the single point mooring buoy 2, and the hose 25 for fresh water.

Next, pressurized water is sprayed from the fresh water tank 12 onto the coal in the hold 11 through the pressure water pump 15 and the pressure water nozzle 16a, and the coal is mixed with water and fluidized (slurried).

This slurry is transferred to the slurry tank 1 by an eductor 17a driven by pressure water from the pressure water pump 14.
Transferred to 3. The slurry in the slurry tank 13 is constantly stirred by the slurry stirring pump 18 during unloading.

The slurry in the slurry tank 13 is unloaded to the coal-fired power plant 4 by the slurry unloading pump 19 through the slurry hose 24, the single-point mooring buoy 2, and the slurry submarine piping 21. The coal in the slurry unloaded to the power plant 4 is separated into pulverized coal and water by the screen 34a, and stored in the coal storage silo 5 by the belt conveyor 9a. The separated pulverized coal and water are guided to the settling tank 6 through a pipe 36 connecting the screen 34a and the settling tank 6.

Next, the handling of coal when transferring the coal from the coal storage silo 5 to the boiler 44 will be explained with reference to FIG.

The total capacity of the coal storage silo 5 is generally equivalent to about two months' worth of coal consumption in the boiler 44. Coal is stored in the coal storage silo 5, and water is sprinkled from the top of the silo as necessary. Therefore, spontaneous combustion of coal during storage and scattering of coal dust are completely prevented.

Coal is discharged from the coal storage silo 5 in accordance with coal consumption in the boiler 44, and the method of discharging is the same as that used when unloading from the ship's hold 11. That is, the pressure water pump 3 is applied to the coal in the coal storage silo 5.
2 injects pressurized water from the pressure water nozzle 16b, the coal is slurried, and transferred to the slurry tank 31 by the eductor 17b, and from there further guided to the dewatering device 7 by the slurry pump 33.

In the dewatering device 7, fine powder and water are separated from the slurry by a screen 34b, and these are led to the settling tank 6 through the screen. screen 34
The lump-like and coarse-grained coal separated by b is led to a coarse-grained coal centrifugal dehydrator 35 and dehydrated. The fine powder of the coal that has passed through the screens 34a and 34b is combined with the waste water from the dehydrator 35 and sent to the sedimentation tank 6.
After precipitation in the dredging plant 3
7, and sent to a centrifugal dehydrator 38 for pulverized coal, where it is dehydrated.

The coal dehydrated in the dehydrators 7 and 8 is transported by belt conveyors 9b, 9c, and 9d, mixed appropriately, and supplied to the bunker 41, and then transferred to the coal feeder 4.
2, it is sent to a crusher 43, where it is pulverized and sent to a boiler 44, where it is combusted. In this way, when importing thermal coal from overseas, it is expected to use a larger ship in order to reduce the sea transportation cost of coal, but the coal unloading method in this example According to the construction and equipment, there is no need for a large quay for berthing large ships, and there is no need for dredging to secure water depth in front of the quay.

There is no need to monopolize the coastline over a wide area, and only the entrance and exit portions of the submarine pipes 21 and 22 require construction on the coastline, and the rest of the coastline can be preserved as it is. In addition, during unloading, coal flows through pumps and pipes in a slurry form, so there is no generation of coal dust.
Furthermore, since different dehydration methods are used depending on the particle size of the coal, it has many advantages such as being able to efficiently supply slurry unloaded coal to the boiler.

Furthermore, before putting the slurry into coal storage silo 5,
By separating coarse grain coal and water containing pulverized coal and charging only the dehydrated coarse grain coal into the coal storage silo 5, no water pressure is applied to the silo 5, which makes the silo 5 have a strong structure. There is no need to lift the slurry to the top of the silo 5, so the lift height of the slurry pump can be reduced.

In this example, as the seaverse,
Although a single-point mooring buoy was adopted, other sea berths other than the single-point mooring buoy may be substituted. For example, it may be a Dolphin type sea berth or a fixed tower type single point mooring. Also, dehydration device 8
Although we adopted a centrifugal dehydrator as the
For example, it may be replaced with a vacuum drum filter or the like.

[Brief explanation of drawings]

Figures 1 and 2 show an embodiment in which the present invention is applied to coal landing and transport, and of these, the first
The figure is a system diagram showing the part for unloading coal, and Figure 2 is a system diagram showing the part for supplying coal from the coal storage silo to the boiler. 1...Coal carrier, 2...Single point mooring buoy, 3...Coastline, 4...Coal-fired power plant, 5...Coal storage silo, 6...
Sedimentation pond, 7, 8... Dehydration device, 10... Pulverized coal-fired boiler building, 11... Ship hold, 12... Fresh water tank, 13...
Slurry tank, 14, 15...Pressure water pump, 17
a, 17b... Eductor, 31... Slurry tank, 3
4a, 34b...Screen, 35...Centrifugal dehydrator for coarse coal, 37...Dredding plant, 38...Centrifugal dehydrator for pulverized coal, 41...Bunker, 42...Coal feeder, 43...Crusher, 44...Boiler .

Claims (1)

[Scope of Claims] 1. Coarse particles transported by sea to the coast in bulk by a carrier ship are mixed and stirred with water sent from land in the carrier ship to form a slurry, and the slurry is After being transported to land, it is separated into coarse particles and water containing fine particles, and then the coarse particles are stored in a storage tank, and the water containing fine particles is stored in a settling tank, where it is further precipitated. A method for unloading coarse particles, which is characterized by extracting and dehydrating the fine particles. 2. Means for supplying water from land in a marine carrier, means for mixing and agitating coarse particles and water in the same carrier to form a slurry, means for transporting the slurry on land within the jurisdiction, and means for transporting the slurry on land. A means for separating the slurry into water containing coarse particles and fine particles, a storage tank for storing the coarse particles separated by the separation means, and a sedimentation tank containing the similarly separated water containing fine particles. 1. A lifting device for coarse granular material, comprising: a means for removing fine powder from the sedimentation tank and a means for dehydrating the fine powder.