JPH0315518B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) This invention is used in the technical field of adjusting the pH of tap water using slaked lime, and particularly relates to a slaked lime solution injection device used in water supply equipment having an elevated tank. .

(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 pH value of tap water. In addition, the above-mentioned slaked lime reacts with carbon dioxide gas in the water when it is in a pipe or tank, forming a calcium carbonate film on the inner wall surface of the pipe or tank, preventing corrosion, eliminating the generation of red water, and extending the life of the pipe or tank. It is also known that there is a second effect called prolongation.

Therefore, in recent years, there has been a trend in the water supply systems of high-rise buildings as well, in which an aqueous solution of slaked lime is injected into city water and then pumped up to an elevated tank that serves as a water supply source. In such water supply systems, installing a set of slaked lime dissolving equipment on the upper floors of high-rise buildings where the elevated tank is installed is often subject to restrictions due to the strength and/or structure of the building, and generally, slaked lime dissolving equipment is After the slaked lime aqueous solution produced in the tank is injected into the water receiving tank, the water is pumped from there to the elevated tank. However, the amount of water stored in the elevated tank fluctuates depending on how water is used on the lower floors, so the water pumps are designed to stop when the tank is full. In such case,
Since the flow of city water into the water tank that receives city water stops almost simultaneously, only the slaked lime aqueous solution is continuously injected into the water tank at a fixed rate, causing the slaked lime content in the water tank to become excessive. There was a problem that occurred.

(Means and effects for solving the problems) The present invention solves the above problems and provides a slaked lime solution injection device for an elevated tank in which the slaked lime content does not vary depending on the amount of water used. Its purpose is to

In order to achieve the above object, the present invention installs a slaked lime dissolving tank having a city water supply pipe at the bottom and a slaked lime aqueous solution intake pipe at the top, and leads the slaked lime aqueous solution intake pipe to a water receiving tank that receives city water. The water receiving tank is connected to an elevated tank installed at a high place via a water pump, and has a water intake stop means for stopping water intake of the slaked lime aqueous solution when the water pump is stopped. It is composed of

In the present invention, city water is once received in a water receiving tank and then stored in an elevated tank by a water pump. At that time, the slaked lime aqueous solution from the dissolution tank is injected into the water receiving tank, improving the pH value of city water. When the elevated tank is full of water, the water pump is stopped, but upon receiving this signal, the water intake stopping means stops the water intake of the slaked lime aqueous solution. As a result, the slaked lime aqueous solution is not injected into the water tank, and the inflow of city water into the water tank also stops almost at the same time, so the optimal PH value is kept almost constant in the water tank. Then, when the water pump operates again, the slaked lime aqueous solution is injected into the water tank, and the pH value remains constant.

When the slaked lime water intake pipe is an overflow pipe, the water intake stopping means is an on-off valve of the city water supply pipe of the slaked lime dissolving tank, and this may be closed when the water pump is stopped. Further, when the slaked lime aqueous solution intake pipe is equipped with a water intake pump, the water intake pump is stopped at the same time as the water pump is stopped, and the on-off valve is also closed.

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

In Fig. 1, 1 is a slaked lime dissolving tank, which has a built-in stirrer 1A, a city water supply pipe 1B with an on-off valve 3 at the bottom, and an overflowing water supply pipe 1B for the slaked lime aqueous solution extending laterally at the top. A flow tube 1C is provided. Furthermore, a hatch 1D for replenishing slaked lime is provided on the lid of the dissolution tank 1, and a pipe 1E for drawing undissolved lime to the undissolved matter tank 2 is also provided at the bottom.

The overflow pipe 1C is led to the water receiving tank 4.
A city water pipe 5 equipped with a liquid level control valve to prevent overflow is connected to the water receiving tank 4 to receive city water, but a part of it passes through a branched pipe to the above-mentioned dissolved water. The water is sent to the city water supply pipe 1B of tank 1. The overflow pipe 1 receives water from the water supply pipe 1B.
The aqueous solution will overflow from C. Therefore, the on-off valve 3 of the water supply pipe 1B functions as a water intake stop means that controls the water intake of the slaked lime aqueous solution.

The water receiving tank 4 is connected at its outflow side via a pump 7 to an elevated tank 8 installed at a high place.

In the apparatus of this embodiment as described above, first, a portion of the city water is sent to the slaked lime dissolving tank 1 from the water supply pipe 1B via the on-off valve 3 which is in an open state. In the slaked lime dissolving tank 1, slaked lime supplied from the hatch 1D is stirred with water from the water supply pipe 1B by the stirrer 1A. As a result, although undissolved lime remains in the lower part of the tank, the upper part becomes occupied by a completely saturated slaked lime aqueous solution, which overflows from the overflow pipe 1C and reaches the water receiving tank 4.

City water from the city water pipe 5 is stored in the water tank 4, and the slaked lime aqueous solution is injected into this tank to improve the pH value of the city water. The improved city water, which has thus reached a predetermined pH value, is pumped by the pump 7 until the elevated tank 8 is filled with water. When water is consumed on the lower floors and the amount of water in the elevated tank 8 decreases, the elevated tank 8 is filled with water by the water pump 7, but once it is full, the water pump 7 stops and the water volume in the elevated tank 8 decreases. The inflow of city water into the water tank 4 is also stopped at almost the same time as the liquid level control valve 6 is operated due to the rise in the liquid level in the tank. When the water pump 7 stops, the on-off valve 3 serving as water intake stopping means closes in response to the signal. By closing the on-off valve 3, the supply of city water is stopped, and the overflow from the slaked lime aqueous solution overflow pipe 1C of the dissolution tank 1 is stopped. In this way, the injection of the slaked lime aqueous solution into the water tank 4 is stopped, and the PH value of the city water in the water tank 4 is maintained at an optimal value.

In addition, if the water receiving tank 4 is installed at a higher position than the dissolving tank 1, the aqueous solution from the dissolving tank can be taken from the water intake pipe 1F as shown in Fig. 2 instead of using the overflow pipe.
This is done by the water intake pump 9. In such a case, the intake pump 9 is of course stopped based on the stoppage of the water pump 7, but the water supply pipe on-off valve 3 is also closed in order to keep the water level in the dissolution tank constant. . In this way, the PH value in the water tank is maintained at a constant value even when the injection of the aqueous solution into the water tank 4 is stopped and the water pump is stopped.

(Effects of the Invention) As described above, in the present invention, when the pumping of water to the elevated tank is stopped, the injection of slaked lime aqueous solution into the water receiving tank is also stopped, so that the city water in the water receiving tank always has a constant pH.
This has the effect of ensuring stable water quality.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an apparatus according to an embodiment of the present invention;
FIG. 2 is a schematic configuration diagram of an embodiment of the apparatus in a case where the water receiving tank is located at a high place in FIG. 1. 1... Slaked lime dissolution tank, 1B... City water supply pipe, 1
C, 1F... slaked lime aqueous solution intake pipe, 3, 9... water intake stop means (3... on/off valve, 9... slaked lime aqueous solution intake pump), 4... water receiving tank, 6... liquid level control valve,
7... Lifting pump, 8... Elevated tank.

Claims (1)

[Scope of Claims] 1. A slaked lime dissolving tank having a city water supply pipe at the bottom and a slaked lime aqueous solution intake pipe at the top is installed, and the slaked lime aqueous solution intake pipe is led to a water receiving tank that receives city water; The water tank is connected to an elevated tank installed at a high place via a lifting pump, and has a water intake stop means for stopping the intake of the slaked lime aqueous solution when the lifting pump is stopped. Solution injection device. 2. Claim 1, characterized in that the slaked lime aqueous solution intake pipe is an overflow pipe extending laterally, and the water intake stop means is an on-off valve provided in the water supply pipe, which is closed when the water pump is stopped. A slaked lime solution injection device for an elevated tank as described in 2. 3. The slaked lime aqueous solution intake pipe is provided with a water intake pump, and the water intake stopping means is an on-off valve that closes when the pump stops, and a water intake pump stopping means that stops the water intake of the slaked lime aqueous solution at the same time. A slaked lime solution injection device for an elevated tank according to item 1.