JPS62288103A - Apparatus for dissolving slaked lime - Google Patents

Abstract

PURPOSE:To prevent the growth of scale in an overflow pipe, by attaching a 1st on-off valve to the attaching base of an overflow pipe laterally attached to the top of a dissolution tank and branching a water-injection pipe furnished with a 2nd on-off valve and directing toward the 1st on-off valve. CONSTITUTION:City water is supplied to a dissolution tank 1 through a water-feed pipe 2 attached to the bottom of the tank 1, slaked lime is charged into the tank 1 through a hatch 12 of a lid 3 and the water containing slaked lime is stirred with a stirring blade 5 and discharged to a well through an overflow pipe 8 laterally attached to the top of the tank 1. A 1st on-off valve 9 is attached to the attaching base of the overflow pipe 8 which is branched with a water-injection pipe 11 having a 2nd on-off valve 10 and directing toward the 1st on-off valve 9. The distance (S) between the injection pipe 11 and the 1st on-off valve 9 is <=2 times the inner diameter (d) of the overflow pipe 8. When the deposition of scale in the overflow pipe 8 reaches a prescribed level, the 1st on-off valve 9 is closed, the 2nd on-off valve 10 is opened and a large amount of water is introduced through the injection pipe 11 into the overflow pipe 8. The injected water dashes against the 1st on-off valve to wash off the scale by the flow energy and vigorously rushes toward the well to wash off the scale on the inner wall of the pipe.

Description

[Detailed description of the invention] 3. Detailed description of the invention (industrial application field) This invention is used in the technical field of pH adjustment of tap water using slaked lime, and in particular, it is used to prevent scaling of overflow pipes. This invention relates to a slaked lime dissolving device.

(Prior Art and Problems) It is known that it is effective to inject an appropriate amount of an aqueous solution of slaked lime in order to improve the water quality by increasing the PL+ value of tap water. In addition, the slaked lime is present in water pipes and reacts with carbon dioxide gas in the water to form a calcium carbonate film on the inner wall of the pipes, which prevents corrosion of the pipes, eliminates the generation of red water, and extends the life of the pipes. It is also known to have the effect of

The aqueous solution of slaked lime is produced in a slaked lime dissolution tank. The dissolution tank has a stirrer, a water supply pipe is attached to the lower part from the outside, and an overflow pipe extending laterally is attached to the upper part. Then, a predetermined amount of slaked lime is introduced from the upper opening of the dissolution tank and is stirred by the water in the tank. Undissolved dissolved lime remains in the lower part of the tank, but the upper part is completely occupied by the slaked lime aqueous solution, and the slaked lime aqueous solution overflows from the overflow pipe due to continuous water supply from the water supply incense. You will be guided to the landing well.

Slaked lime reacts with carbon dioxide gas in water as described above, and also reacts with carbon dioxide gas in the air to produce calcium carbonate. This then scales on the inner wall surface of the tube. This lucium carbonate does not easily dissolve in water, and furthermore, scaling progresses rapidly in the overflow pipe, causing blockage of the pipe and making it difficult or impossible to transport the slaked lime aqueous solution. There is also.

Conventionally, there has been no good solution to the above-mentioned problems, and the development of a solution has been required.

(Means and effects for solving the problems) The present invention was developed in response to the above-mentioned requirements, and provides a slaked lime dissolving device that does not cause blockages by periodically washing with water before scaling grows. Its purpose is to Furthermore, it is another object of the present invention to provide a device that can suppress the growth of scaling itself.

To achieve the above object, the present invention provides a water supply pipe at the lower part of a dissolution tank incorporating a stirrer, and an overflow pipe extending laterally at the upper part, and the overflow pipe includes a mounting base of the overflow pipe. The first on-off valve is provided with a first on-off valve, and the water injection pipe of the first on-off valve 9, which is directed in the direction of the first on-off valve, is branched and attached at a position close to the first on-off valve.

In the above device, when the scaling reaches a certain value, the first on-off valve is closed and the second on-off valve is opened to send a large amount of water from the water injection pipe into the overflow pipe. Since the water injection pipe is located close to the first on-off valve and is oriented toward the first on-off valve, the water sent through the water injection pipe has an impact on the first on-off valve, which is the end of the overflow pipe. After that, the water flows vigorously through the overflow pipe in the direction of the receiving well, washing away the scaling from the pipe wall.

In order to ensure sufficient cleaning by the flow rate of water hitting the first on-off valve, the installation position of the water injection pipe to the overflow pipe must be such that the distance between the installation position and the first on-off valve is close to that of the overflow pipe. It is desirable that the diameter be within twice the inner diameter.

Furthermore, in order to suppress the growth of scaling, the apparatus of the present invention having the above structure divides the space above the water surface into a small space on the overflow pipe installation side and a large space in the remaining part. It is desirable to have a partition wall with a small opening that communicates with the large space.

In such a case, the inflow of air into the overflow pipe is restricted by the partition wall in the tank, the reaction with air in the overflow pipe is reduced, and the growth of scaling is suppressed.

(Example) An example of the present invention will be described below based on the accompanying drawings.

In FIG. 1, 1 is a vertical cylindrical dissolving tank.

A water supply pipe 2 is connected to the lower part of the dissolution tank 1 to supply water into the tank. At approximately the center of the lid plate 3 of the dissolution tank 1, the rotating shaft 4
extends downward through the rotary shaft 4, and a stirring blade 5 is attached to the lower end of the rotary shaft 4, forming a stirrer. Also, cover plate 3
A hatch 12 is provided on the left side of the hatch 12, from which slaked lime is introduced. In addition, a hatch 6 is provided on the right side of the lid plate 3,
.

From there, an overflow riser pipe 7 extends below the overflow liquid level in the tank. A booth lower A communicating with the surrounding space is provided at the upper part of the overflow screen riser pipe 7.

A laterally extending overflow pipe 8 is attached to an intermediate portion of the overflow riser pipe 7 and extends through the side wall of the dissolution tank 1. The overflow pipe 8 extends to the right and reaches a landing well (not shown).

At the base of the overflow pipe 8 is a first on-off valve 9 that can be opened and closed outside the tank.
is attached. Furthermore, an injection pipe 1) having a second on-off valve lO in the vicinity of the first on-off valve 9 is branched from the overflow pipe.

The injection pipe 1) is mounted so as to face the first on-off valve 9, and its mounting position is such that the distance S from the first on-off valve 9 is less than about twice the inner diameter d of the overflow pipe 8. It is desirable that the range be small.

In the apparatus of this embodiment, normally, slaked lime introduced from the hatch 12 is stirred and mixed with water supplied from the water supply pipe 2 by the stirrer.

A sufficient slaked lime aqueous solution is then completed. A dissolved solution containing undissolved dissolved lime remains in the lower part of the tank, and only the complete aqueous solution flows out from the attachment port of the overflow pipe 8 through the first on-off valve 9, which is in an open state, and is brought to the landing well. At this time, the second on-off valve 10
is in a closed state.

When the aqueous solution flows into the overflow pipe 8, the space leading to the overflow pipe is small due to the presence of the overflow riser pipe 7 as a partition wall, so that the aqueous solution flows into the overflow pipe 8. There is little air. Therefore, scaling due to reaction with air within the overflow pipe 8 is suppressed. In this embodiment, the overflow riser pipe 7 is used as a partition wall, but a flat plate or the like may be separately provided, for example, hanging from the cover plate 3. The air in the overflow riser pipe 7 is gradually replenished from the surrounding large space through the lower booth 8.

Next, in order to prevent blockage by washing with water at a constant Q before scaling grows, the water supply through the water supply pipe 2 is stopped, the first on-off valve 9 is closed, and the second on-off valve 10 is closed. open. Then, the cleaning water violently hits the first on-off valve 9 and removes the scaling, then changes its direction and flows forcefully through the overflow pipe 8 toward the landing well, causing the inner wall surface of the overflow pipe 8 to be damaged by the flow velocity. It washes away the scaling. In this way, the scaling of the overflow pipe 8 can be removed by the water flow, so that even if the pipe is bent, it will not be affected by it.

(Effect of the invention) The present invention is provided with a water injection pipe that jets water toward the first on-off valve of the overflow pipe, so that the end of the overflow pipe that reaches the first on-off valve is This has the effect of completely preventing scaling and extending the life of the pipe. In addition, if a partition wall is provided in the dissolution tank, the growth of scaling in the overflow pipe can be suppressed, and the interval until the next maintenance period for the overflow pipe can be lengthened.
Furthermore, it has the effect of making maintenance easier.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional view showing an apparatus according to an embodiment of the present invention.

Claims (3)

[Claims] (1) A water supply pipe is provided at the bottom of the dissolution tank containing a built-in stirrer, and an overflow pipe extending laterally is provided at the top, and a first on-off valve is provided at the mounting base of the overflow pipe. A slaked lime dissolving device further comprising a branched water injection pipe with a second on-off valve oriented toward the first on-off valve and installed in a position close to the first on-off valve. (2) The mounting position of the water injection pipe to the overflow pipe is characterized in that the distance between the mounting position and the first on-off valve is within twice the inner diameter of the overflow pipe. The slaked lime dissolving device described in ). (3) The dissolution tank is equipped with a partition wall that divides the space above the water surface into a small space on the overflow pipe attachment side and a large remaining space, and has a small opening that communicates the small space with the large space. A slaked lime dissolving device according to claim (1).