JPH04235706A - Device for dewatering granulated slag slurry - Google Patents

Abstract

PURPOSE:To eliminate occurrence of choking phenomenon and enhance dewatering efficiency by providing an auxiliary dewatering chamber having an opening extending upwardly from the vicinity of the opening position of a dewatering chamber, over the opening of which a water-permeable screen is stretched. CONSTITUTION:When granulated slag slurry is fed to a dewatering tank 1, the slag 6 precipitates in the tank to form an accumulated layer 6A and when the upper level of the layer 6A exceeds the level of openings 2a of the chamber 2, dewatering from the chamber 2 is initiated. When the upper surface level of the layer 6A exceeds the lower end of an auxiliary dewatering chamber 3, a shutter member 4 rises to release the lower end of openings 3a of the chamber 3 so that dewatering from the chamber 3 is effected, following which as the upper level of the layer 6A rises, the shutter member 4 rises by the amount of the rise of said level and the opened region of the openings 3a extends upwarly as the level of the layer 6A rises.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a dewatering device for gravity dewatering granulated slag slurry obtained by water-cooling and crushing molten slag discharged from a blast furnace, etc.
Specifically, a dehydration chamber is provided at the bottom of the dehydration tank, and the dehydration chamber is opened into the dehydration tank and has a water-permeable screen stretched over the opening. The present invention relates to a dehydration treatment device configured to exude slurry water into a chamber.

0002

[Prior Art] A conventional dehydration device of this type is shown in Fig. 5.
As shown in FIG. 2, a device in which an annular dehydration chamber 22 is provided at the bottom of a dehydration tank 21 is known. The dehydration chamber 22 opens into the dehydration tank 21 and is connected to a drainage channel 28 . A water-permeable screen 27 is provided over the opening 22a of the dehydration chamber 22, and an on-off valve 28a is provided in the drainage channel 28. Furthermore, an overflow chamber 21c is provided in the upper part of the dehydration tank 21 and communicated with the drainage channel 28. In such a conventional device, when the granulated slag slurry 6 is supplied to the dewatering tank 21, the granulated slag 6a settles to form a deposited layer 6A. Then, when the on-off valve 28a is opened when the granulated slag accumulation layer 6A has been formed to a level that buries the opening 22a of the dehydration chamber 22, the slurry water 6b naturally flows down inside the granulated slag accumulation layer 6A. Then, it oozes out into the dehydration chamber 22 through the screen 27. At this time, fine solid substances such as fine granulated slag and slag wool mixed into the slurry water 6b are collected while passing through the granulated slag accumulation layer 6A. In other words, the granulated slag accumulation layer 6A exhibits a so-called sand filter function. Therefore, slurry water 6b containing almost no solid substances is exuded into the dehydration chamber 22.
This exudate water is discharged into the drainage channel 28. On the other hand, dehydration chamber 2
The surplus slurry water 6b that is not discharged into the slurry 2 remains on the granulated slag accumulation layer 6A, but when the level of the remaining water exceeds a certain level, it overflows into the overflow chamber 21c and is discharged into the discharge passage 21d. By the way, the drain channels 21d and 28 are led to a hot water tank, and the slurry water 6 discharged into the drain channels 21d and 28 is
b is supplied to a hot water tank, cooled, and then reused as injection water for granulation.

0003

[Problems to be Solved by the Invention] However, in such a conventional device, the amount of water exuding into the dehydration chamber 22, that is, the amount of dewatered water, is reduced within a short period of time (generally, 1 hour) from the point of opening of the on-off valve 28a.
After about 5 minutes, the dehydration rate decreased sharply, and the dehydration rate further decreased as time passed, resulting in a problem that the dehydration efficiency was extremely low. That is, as the slurry water 6b flows down the granulated slag accumulation layer 6A, fine solid substances such as the above-mentioned slag wool are collected in the lower part of the granulated slag accumulation layer 6A, so that the dehydration chamber A high-density layer 6B extending in the horizontal direction is formed in the vicinity of 22. Such a high-density layer 6B grows in a short time and becomes slurry water 6b.
flow into the dehydration chamber 22 (hereinafter, such a phenomenon will be referred to as "choking phenomenon"). As a result, as the level of the granulated slag accumulation layer 6A increases, the slurry water 6b
Coupled with the increased passage resistance within the granulated slag accumulation layer 6A, the amount of water removed is drastically reduced. Moreover, as the amount of dewatering decreases, the amount of water discharged from the overflow chamber 21c to the hot water tank increases, but the slurry water 6b discharged from the overflow chamber 21c is not subjected to the sand filter action by the granulated slag accumulation layer 6A. Because it contains a large amount of solid material,
If slurry water 6b containing such solid substances is reused as injection water for granulation, various equipment troubles will occur (for example, damage to piping, wool adhering to cooling towers, etc., may impede its functionality). etc.).

[0004] The present invention has been made in view of the above points, and can greatly improve dehydration efficiency, and can also discharge only clean water with an extremely low solid content from the dehydration tank. It is an object of the present invention to provide a dewatering treatment device for granulated slag slurry that can be reused without any problems.

[0005]

[Means for Solving the Problems] The dehydration treatment apparatus of the present invention which solves this problem is particularly arranged in a substantially central part of the dehydration tank connected to the drainage channel, and near the opening position of the dehydration chamber. The sub-dehydration chamber has an opening extending upward from the top and a water-permeable screen is placed over the opening, and the sub-dehydration chamber is movable up and down in order to open and close the opening, and the open area of the opening is raised and lowered. a shutter member that can increase or decrease in the vertical direction with respect to its lower end; and a shutter member that can be raised and lowered based on the upper surface level of the granulated slag deposited layer to raise and lower the upper surface of the granulated slag deposited layer at the opening of the sub-dehydration chamber. A shutter operating mechanism that opens only the portion below the level is provided.

[0006]

[Operation] When the granulated slag slurry is supplied to the dehydration tank, the granulated slag settles in the dehydration tank to form a granulated slag accumulation layer, and the upper surface level of the granulated slag accumulation layer reaches the opening of the dehydration chamber. When the temperature exceeds the limit, dehydration from the dehydration chamber starts. When the upper surface level of the granulated slag accumulation layer exceeds the lower end of the sub-dehydration chamber, the shutter member is raised to open the lower end of the opening of the sub-dehydration chamber, and dewatering from the sub-dehydration chamber is started. . Thereafter, as the upper surface level of the granulated slag accumulation layer rises, the shutter member is raised by an amount corresponding to the amount of rise. That is, the open area of the sub-dehydration chamber opening is expanded upward in accordance with the rise in the level of the granulated slag deposit layer. Note that this open area is not expanded to the top of the granulated slag deposit layer. In this way, since the open area of the opening of the sub-dehydration chamber, that is, the area where slurry water seeps into the sub-dehydration chamber, gradually expands as the level of the granulated slag accumulation layer rises, the amount of water removed from the sub-dehydration chamber increases. increases as the level of the granulated slag layer increases. Moreover, the opening of the sub-dehydration chamber is always
Since almost the entire area in the vertical direction of the granulated slag accumulation layer is opened, that is, the flow of slurry water to the sub-dehydration chamber is performed in almost the entire area in the vertical direction of the granulated slag accumulation layer. Therefore, fine solid substances such as slag wool are not concentrated in one place in the vertical direction, and a high-density layer that blocks the flow path of slurry water is not formed. Even if a high-density layer is formed due to the concentration of fine solid materials, it is formed along the vertical direction by the approximately horizontal flow of slurry water toward the opening of the sub-dehydration chamber that extends vertically. Therefore, there is no possibility that the formation of a high-density layer will impede the flow of slurry water. In other words, the choking phenomenon does not occur at all. Therefore, the amount of water removed does not decrease over time, and the efficiency of water removal is greatly improved. In addition, since the portion of the opening of the sub-dehydration chamber that is higher than the level of the granulated slag accumulation layer is closed by the shutter member, the slurry water remaining on the granulated slag accumulation layer does not enter the sub-dehydration chamber. . Therefore, from the dehydration tank, only clean water from which most of the solid substances have been removed by the sand filter action of the granulated slag deposited layer is discharged, and this discharged water causes the problems mentioned at the beginning. It can be reused without problems.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be specifically explained below based on the embodiments shown in FIGS. 1 to 3. In the dehydration treatment apparatus shown in FIG. 1, 1 is a dehydration tank, 2 is a dehydration chamber, 3 is a sub-dehydration chamber,
4 is a shutter member, and 5 is a shutter operating mechanism. Granulated slag slurry 6 is supplied to the dewatering tank 1 from the supply port 1a at the top thereof.
The dehydrated granulated slag 6a is taken out from the outlet ports 1b, 1b at the bottom of the tank. The dehydration chamber 2 is provided at the bottom of the dehydration tank 1.
It has a ring shape that spans the entire circumference. The inner periphery of the dehydration chamber 2 is opened into the dehydration tank 1, and a water permeable screen 7 is stretched over the opening 2a. The screen 7 may be made of rod material 7a having a trapezoidal cross section, for example, as shown in FIG.
A wedge wire screen consisting of a combination of... is used. Further, a drainage channel 8 is connected to the dehydration chamber 2, and by opening an on-off valve 8a of the drainage channel 8, slurry water 6 is removed.
b is exuded from the granulated slag accumulation layer 6A into the dehydration chamber 2, and is discharged from the dehydration chamber 2 into the drainage channel 8. Note that the drainage channel 8 is led to a hot water tank as in the conventional device. The sub-dehydration chamber 3 is, as shown in FIGS. 1 and 3,
It is fixedly arranged approximately at the center of the dehydration tank 1, has an opening 3a extending upward from near the opening position of the dehydration chamber 2, and has a water permeable screen 9 stretched over the opening 3a. In this embodiment, the sub-dehydration chamber 3 has a rectangular cylindrical shape with its upper and lower ends closed, and the peripheral wall is formed with a wedge wire screen 9 similar to that described above, so that the sub-dehydration chamber 3 can be The opening 3a is formed entirely in the circumferential direction. A drainage channel 10 led to the hot water tank is connected to the sub-dehydration chamber 3, and by opening the on-off valve 10a of the drainage channel 10, slurry water 6b flows into the granulated slag accumulation layer 6.
It oozes out from A into the sub-dehydration chamber 3 and is discharged into the hot water tank via the drainage channel 10. As shown in FIGS. 1 and 3, the shutter member 4 is composed of a rectangular cylindrical body that is fitted into the sub-dehydration chamber 3 from above, and is raised and lowered to move the open area of the opening 3a up and down with respect to its lower end. It can be increased or decreased in the direction. That is, by lowering the shutter member 4, the opening 3a is gradually closed from the upper end, and conversely, by raising the shutter member 4, the opening 3a is gradually opened from the lower end. As shown in FIG. 1, the shutter operating mechanism 5 includes a shutter member 4
Lifting drive means 11 for lifting and lowering the granulated slag accumulation layer 6A
Level detector 12 and detector 12 for detecting the upper surface level of
A controller 13 for controlling the drive means 11 based on the detection level detected by
Only the portion of the opening 3a below the upper surface level of the granulated slag deposit layer 6A is opened. As the elevating and lowering driving means 11, for example, as shown in FIG. 1, there is used one constructed so that the shutter member 4 is suspended by a hoisting rope 11a and the rope 11a is hoisted and driven. In addition, in this embodiment, the dehydration chamber 2
A cleaning water jetting passage 15 is guided to a nozzle pipe 14 arranged in the sub-dehydrating chamber 3, and the screens 7, 9 are cleaned by jetting cleaning water from the jetting passage 15 into the dehydrating chambers 2, 3. We have devised ways to make it possible. In the dehydration treatment apparatus configured as above, when the granulated slag slurry 6 is supplied to the dehydration tank 1, the granulated slag 6a settles in the dehydration tank 1, forming a granulated slag accumulation layer 6A. When the upper surface level of the granulated slag accumulation layer 6A exceeds the opening 2a of the dehydration chamber 2, the opening/closing valve 8a is opened to start dewatering from the dehydration chamber 2. Furthermore, when the upper surface level of the granulated slag accumulation layer 6A exceeds the lower end of the sub-dehydration chamber 3, the lower end portion of the sub-dehydration chamber opening 3a is opened by the shutter member 4, and dewatering from the sub-dehydration chamber 3 is started. be done. Thereafter, as the level of the granulated slag accumulation layer 6A increases, the shutter member 4
The amount by which the opening 3a is opened is gradually increased. In this way, since the open area of the sub-dehydration chamber opening 3a expands upward as the level of the granulated slag accumulation layer 6A increases, the amount of water dewatered from the sub-dehydration chamber 3 increases as the granulated slag accumulation layer 6A increases.
It increases as the level of A increases. Moreover, the sub-dehydration chamber opening 3a is always opened over substantially the entire area in the vertical direction of the granulated slag accumulation layer 6A, regardless of the level fluctuation of the granulated slag accumulation layer 6A. The flow of slurry water 6b to the sub-dehydration chamber 3 causes the granulated slag accumulation layer 6
Since the process is carried out over almost the entire area in the vertical direction of A, fine solid substances such as slag wool are not concentrated in one place in the vertical direction, and a high-density layer 6B is formed that blocks the flow path of the slurry water 6b. There is no such thing as forming. Even if a high-density layer 6B is formed due to the concentration of fine solid materials, it is caused by the approximately horizontal flow of slurry water toward the vertically extending sub-dehydration chamber opening 3a. (see FIG. 1), there is no possibility that the formation of the high-density layer 6B will impede the flow of the slurry water 6b, and no choking phenomenon will occur. Therefore, the amount of water removed does not decrease over time, and the efficiency of water removal is greatly improved. Further, since the portion of the sub-dehydration chamber opening 3a that is higher than the level of the granulated slag accumulation layer 6A is closed by the shutter member 4, the slurry water 6 that remains on the granulated slag accumulation layer 6a is closed.
b will not enter the sub-dehydration chamber 3. Therefore, only clean water from which most of the solid substances have been removed through the sand filter action of the granulated slag accumulation layer 6A is discharged from the drainage channels 8 and 10 to the hot water tank.
The water discharged from the dehydration tank 1 can be reused without any problem.

The dehydration treatment apparatus according to the present invention is not limited to the above-mentioned embodiments, but can be modified and modified as appropriate without departing from the basic principles of the present invention. For example, as shown in FIG. 4, a bubbling pipe 16 for blowing out air or steam 16a may be provided at the lower part of the dehydration tank 1 to agitate the granulated slag deposit layer 6A by bubbling. In this way, the high density layer 6B
It is expected to have the effect of preventing the formation of slag or destroying the generated high-density layer 6B, reducing the passage resistance of the slurry water 6b through the granulated slag accumulation layer 6A, and further improving the dewatering efficiency. can be achieved. Further, the number of sub-dehydration chambers 3 to be installed can be determined arbitrarily depending on the size of the dehydration tank 1 and the like. Further, the shutter operating mechanism 5 may be one that manually controls the shutter member 4 to move up and down depending on the upper surface level of the granulated slag accumulation layer 6A.

[0009]

Effects of the Invention As can be easily understood from the above explanation, according to the present invention, water can be dehydrated from substantially the entire vertical direction of the granulated slag accumulation layer, regardless of the level of the granulated slag accumulation layer. Therefore, the dewatering efficiency can be greatly improved without causing the choking phenomenon. Moreover, only the clean water that has been subjected to the sand filter action by the granulated slag deposited layer is discharged from the dewatering tank, so that it can be reused without any problem.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view showing an embodiment of a dehydration treatment apparatus according to the present invention.

FIG. 2 is a cross-sectional plan view of essential parts taken along line II-II in FIG. 1;

FIG. 3 is a cross-sectional plan view of main parts taken along line III-III in FIG. 1;

FIG. 4 is a longitudinal side view showing another embodiment.

FIG. 5 is a longitudinal side view showing a conventional device.

[Explanation of symbols]

1 Dehydration tank 2 Dehydration room 2a Opening of dehydration chamber 3. Secondary dehydration room 3a Opening of sub-dehydration chamber 4 Shutter member 5 Shutter operation mechanism 6. Granulated slag slurry 6A Granulated slag sediment layer 6a Granulated slag 6b Slurry water 7 Water permeable screen 8 Drainage channel 9 Water permeable screen 10 Drainage channel

Claims (1)

[Claims] Claim 1: A dehydration chamber is provided in the lower part of the dehydration tank and has a water-permeable screen stretched over the opening of the dehydration tank, and the water is removed from the granulated slag deposited layer that settles and forms in the dehydration tank. In a dehydration treatment device configured to ooze slurry water into a chamber, an opening that is connected to a drainage channel, is disposed approximately in the center of the dehydration tank, and extends upward from near the opening position of the dehydration chamber. and a sub-dehydration chamber with a water-permeable screen stretched over its opening, which is movable up and down to open and close the opening of the sub-dehydration chamber, and by raising and lowering, the open area of the opening is referenced to its lower end. A shutter member that can be increased and decreased in the vertical direction, and a portion below the upper surface level of the granulated slag accumulation layer at the opening of the sub-dehydration chamber by raising and lowering the shutter member based on the upper surface level of the granulated slag accumulation layer. A dewatering treatment device for granulated slag slurry, comprising: a shutter operation mechanism for opening only the shutter;