JPH0110390Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a slurry storage tank, in particular, in which a sedimentation substance is mixed into the slurry. The present invention relates to a slurry storage tank that can be stored for a long period of time.

Conventionally, in order to maintain high-concentration slurry at a constant concentration, especially in large slurry storage tanks, the liquid flow energy generated from a stirring source such as an agitator affects the entire liquid storage, and due to that influence, Sedimentable substances in the liquid must be kept in suspension. For this reason, when using a stirring device, a large storage tank with high horsepower and high speed stirring blades (for example, a diameter of 50 mφ from around 15 mφ and a height of 15 to 20 m) is required.
This would require a large stirring device corresponding to the size of the container. Such a stirring device requires a large amount of power consumption and accelerates the wear of the stirring blades, making it impractical to implement.

Conventionally, in order to homogenize the slurry in this large slurry storage tank, instead of stirring it with a stirring device to make it homogeneous, a method was used to prevent sedimentary substances in the slurry from accumulating on the bottom of the storage tank, or to prevent sedimentary substances from accumulating at the bottom of the storage tank. There is a storage tank having a so-called pump circulation system as shown in FIG. 3, in which the slurry at the bottom and the vicinity thereof is constantly scraped up and removed from the bottom of the storage tank, and then circulated to the liquid surface of the same storage tank. In this pump circulation system storage tank, the pump 10 extracts the slurry liquid that has become thicker than the standard concentration in the storage tank, and replenishes it to the upper layer of the storage liquid that has become diluted than the standard concentration. The practice is to make the reservoir fluid and maintain the slurry at a constant concentration.

Therefore, the flow state in this case is always directed from the upper part of the liquid toward the lower part by the circulation operation of the slurry driven by the pump 10. As a result, the sedimentation rate of the sedimentation substances in the slurry is faster than the behavior of the sedimentation substances in the slurry when the liquid is standing still. This property of rapidly settling materials is also a drawback of the pump circulation system slurry storage tank described above.

That is, the drawback is that a highly concentrated slurry can always remain at the bottom of the storage tank, which increases the load or load fluctuation of the scraping device and the slurry circulation pump.

This invention relates to an improved technology devised to reduce the above-mentioned problems of large slurry storage tanks with pump circulation systems. By injecting gas into the solid matter, the solid matter is diffused or given buoyancy, and its apparent specific gravity is reduced, and the gas rises to the middle and upper layers of the stored liquid. It is an object of the present invention to provide a slurry storage tank that can reduce the settling speed of sedimentary substances surrounding floating gas and increase the residence time of the sedimentary substances in the storage tank.

The present invention will be explained in detail below with reference to FIGS. 1 and 2.

The drawing shows an example of a COM, that is, a storage tank for a suspended mixed liquid of granular coal and oil. It is suspended so as to be rotatable in the horizontal direction by a rotary drive device 5 installed on a superstructure 4 erected outside, and these are conventionally known structures.

In the present invention, a gas jet nozzle is arranged at the bottom of the storage tank, below the raking device.More specifically, a flow pipe 6 is arranged along the rake cage 2 and the rake arm 3, and the upper part of the flow pipe 6 is connected to the drive device. 5
It passes through the inside of the shaft, and its upper end is connected via a rotary joint to a supply pipe 7 that is directly connected to a gas supply device (not shown) such as air or inert gas outside the tank. It is characterized in that a plurality of nozzles 8 are provided in the disposed flow pipe 6.

The storage slurry supplied into the main body 1 from the upper part of the storage tank main body 1 is scraped up by the rotation of the rake arm 3, and the slurry at the bottom of the tank is scraped up by the scraper 9. At the same time, a gas such as air or an inert gas, which is pumped from a gas supply device, can be ejected into the slurry from each nozzle 8.

In the vicinity of the scraper 9 that rotates according to the rake arm 3, there is a slurry that has become more concentrated and viscous than other parts of the slurry due to the settling action of the settling solids in the slurry. This portion is partially stirred in an undefined direction by a plurality of nozzles 8 attached to the scraping device A.

This partial stirring device has the effect of reducing the apparent specific gravity of the slurry that is easily fixed at the bottom of the storage tank and the slurry in the previous stage, improving the scraping ability of the scraping device, reducing the load, and further improving the circulation pump. Increases liquid pumping capacity and reduces load.

Then, the blast force and rising airflow of the gas discharged from these nozzles 8 retard the sedimentation speed of the sedimentary substances in the slurry in the main body 1, and as a result, in cooperation with the force of the pump to circulate the slurry, The slurry as a whole maintains a tendency to be homogenized under the fluid state, and the rake arm 3 can maintain a high concentration and high viscosity slurry constant for a long period of time even when rotating at a low speed.

The flow pipe 6 is designed to rotate simultaneously with the rotation of the rake cage 2 and rake arm 3.
Since the flow pipe 6 is connected to the supply pipe 7 outside the tank by a rotary joint, there is no problem in pressurizing the gas.

The nozzle 8 may simply eject gas into the slurry, but if a nozzle with a check valve is used, the slurry will not enter into the nozzle 8 and the pipe 6 while the gas supply is stopped.

The jetting direction of the nozzles 8 is preferably downward in most cases, but may be horizontal or upward, and all the nozzles 8 may be capable of jetting in different directions.

If a lifting device (lifting device) is appropriately installed in the super structure 4, and the rake cage 2 and the rake arm 3 are raised and lowered at the same time by raising and lowering the drive unit 5, the height and low position of the jet from the nozzle 8 can be adjusted. In addition, the liquid fluidity at the bottom of the slurry can be improved to perform a raking operation.

In addition, compared to the conventional case using only gas stirring, the present invention has a small amount of gas when considering the amount of liquid stored, and it is possible to raise the gas sequentially and completely inside the storage tank, and the arrangement of the blow nozzle Able to select appropriate settings. As a result, it is possible to obtain a desirable sedimentation pattern of sedimentary substances in the stored liquid, and to enhance the raking effect of the raking device.

As described above, according to the present invention, as the slurry is scraped up by the scraping device, a diffusion effect is applied to the slurry layer at the bottom of the storage tank, and an effect of suppressing the sedimentation rate of sedimentary substances is performed on the slurry in the middle and upper layers. Because of these two effects, the slurry can maintain a constant concentration and viscosity for a long period of time, and since the scraping device can be rotated at a low speed, the driving power consumption can be reduced.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; Fig. 1 is a schematic front view of the entire slurry storage tank, Fig. 2 is an enlarged front view of the main parts, and Fig. 3 is an explanatory diagram showing an example of the pump circulation system storage tank. It is. 1 is a storage tank body, 2 is a rake cage, 3 is a rake arm, 5 is a rotary drive device, 6 is a flow pipe, 7 is a supply pipe, 8 is a nozzle, and 10 is a pump.

Claims (1)

[Scope of utility model registration request] In order to homogenize the slurry, in a pump circulation system slurry storage tank that has a rotatable scraping device at the bottom and a pump that circulates the slurry scraped by the scraping device to the upper part of the storage tank, the lower part of the scraping device is used. A slurry storage tank characterized by having a gas jet nozzle installed in the tank.