JPH11128957A - Improvement of quality of city water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To downsize an apparatus having at least a specified number of water receiving tanks by producing a nearly saturated hydrated lime aqueous solution in a hydrated lime dissolving tank and a carbonic acid aqueous solution having a prescribed free carbonic acid concentration by a free carbonic acid concentration adjustment device and supplying these solutions to the tanks. SOLUTION: A nearly saturated hydrated lime aqueous solution W2 is produced in a hydrated lime dissolving tank 1 and supplied to two water receiving tanks 7a, 7b through an aqueous solution supply pipe 6. A carbonic acid aqueous solution W4 having a prescribed free carbonic acid concentration is produced by a free carbonic acid concentration adjustment device 11 and supplied to the tanks 7a, 7b through a carbonic acid aqueous solution supply pipe 18. Quality-improved water W6 is produced from the solutions w2 , w4 and city water W as raw water in the tanks 7a, 7b. In this process, since quality- improved water W6 can be produced by the use of one hydrated lime dissolving tank 1 and one free carbonic acid concentration adjustment device 11 and two water receiving tanks 7a, 7b, an apparatus can be downsized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tap water reforming apparatus, and more particularly to a tap water reforming apparatus in which a substantially saturated aqueous solution of slaked lime is injected into tap water to reform the tap water. .

[0002]

2. Description of the Related Art Conventionally, in existing buildings and high-rise houses, the inside of water supply pipes is corroded and red water is generated, which is often a problem. An injection method, a lining method, a slaked lime injection method, and the like are known. This method of slaked lime injection not only prevents red water, but also has a great power to improve the Langeria index (index for determining the corrosiveness of water) and that calcium as the main component is said to be good for health. Many have been implemented recently. In this slaked lime injection method, slaked lime is charged into a slaked lime dissolving tank having a stirrer and a part of tap water is supplied and stirred, slaked lime is dissolved in the tap water to produce a slaked lime substantially saturated aqueous solution. For the free carbon dioxide concentration controller,
Another part of tap water and carbon dioxide gas are injected to form carbonated water having a predetermined free carbonic acid concentration, and the carbonated water, the above-described substantially slaked lime aqueous solution, and tap water as raw water are received at a predetermined ratio. The water is supplied to a water tank to improve the quality of the tap water. That is, the tap water is reformed to improve the Langeria index and slaked lime reacts with carbon dioxide in the tap water, specifically, free carbon dioxide to generate calcium carbonate, thereby increasing the calcium content in the tap water. At the same time, the calcium carbonate adheres to the inner wall of the water pipe to form a film, and this film prevents the generation of red water. In this slaked lime injection method, a substantially saturated aqueous solution of slaked lime is injected into tap water, which is raw water, and a predetermined P
In order to reform tap water whose H value is less than or equal to the PH value (8.6 or less according to the regulations of the Waterworks Bureau) and the Langeria index is close to zero,
It is important to control the concentration of free carbonic acid contained in tap water. Therefore, it is known that the concentration of free carbonic acid in tap water as raw water is measured, the amount of carbonic acid gas injected is controlled, the free carbonic acid concentration in tap water is set to a predetermined value, and then supplied to a receiving tank ( For example, JP-A-2-194893). Then, an approximately saturated aqueous solution of slaked lime corresponding to the supply amount of tap water supplied to the water receiving tank is supplied into the water receiving tank. The tap water that has been improved (reformed) in the water receiving tank in this way is supplied to a place of use, for example, an apartment house by a water pump.

[0003]

By the way, conventionally, in a conventional existing apartment house, tap water is temporarily stored in a receiving tank and then sent to an elevated water tank or each house by a water pump. A plurality of (usually two) water receiving tanks are provided to prevent water interruption during cleaning. In order to adopt the above-described tap water reforming apparatus in an apartment house having a plurality of water receiving tanks, it is necessary to provide a slaked lime dissolving tank and a free carbon dioxide concentration adjusting apparatus for each of the water receiving tanks. Therefore, there is a problem that not only the entire device becomes large and a large installation area is required, but also the production cost is increased and the operation management cost is also increased.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and comprises mixing a part of tap water and slaked lime to form a substantially saturated slaked lime aqueous solution. A slaked lime dissolving tank to be manufactured, a free carbon dioxide concentration adjusting device for injecting carbon dioxide gas into a part of tap water to form a carbonated water having a predetermined free carbon dioxide concentration, and the slaked lime substantially saturated aqueous solution, the carbonated water and raw water. It is composed of at least two or more water receiving tanks that are mixed with tap water to form reformed water, and the slaked lime dissolving tank and each of the water receiving tanks are connected by different aqueous solution supply pipes each having an aqueous solution injection device, A tap water reformer in which a different carbonated water supply pipe having a control valve is connected to each of the free carbon dioxide concentration adjusting device and each of the water receiving tanks, and a tap water supply pipe as raw water is connected to each of the water receiving tanks. Quality equipment Is shall. According to the tap water reforming apparatus having such a configuration, one slaked lime dissolving tank and a free carbon dioxide concentration adjusting device are used. It can be supplied to the water receiving tank, and the size of the device can be reduced. Preferably, a liquid level gauge is provided in each of the water receiving tanks, and the supply amounts of tap water, which is raw water supplied into each of the water receiving tanks in accordance with a signal from the liquid level gauge, and a substantially saturated aqueous solution of slaked lime and carbonated water are specified. Is controlled to be the ratio of More specifically, each receiving tank is provided with an upper level gauge and a lower level gauge, respectively, and when the reformed water produced in each of the receiving tanks is sent to the place of use, the level of the liquid drops. Come.
When the liquid level reaches the lower liquid level, a signal is issued from the lower liquid level gauge, and a valve element provided in the supply pipe of tap water as raw water, an aqueous solution injection device arranged in the aqueous solution supply pipe, a carbonated water supply pipe. By operating a control valve disposed in the water supply tank, a substantially saturated aqueous solution of slaked lime, carbonated water, and tap water as raw water are supplied at a predetermined ratio into the water receiving tank, and reformed water is produced here. Then, when the liquid level in the water receiving tank rises and reaches the upper liquid level, the signal from the upper liquid level meter stops the aqueous solution injector and closes the control valve and the valve body.
When each water tank is arranged at a relatively short distance, one end of a unit water pipe is connected to each water tank, and the other end of the unit water pipe is connected to a main water pipe having a water feeding device. You. The main water supply pipe and the upstream side of the water supply device and the water receiving tank are connected by a return pipe of the reformed water having a pump and a PH detector. By operating the pump, the reformed water in the main water supply pipe is operated. PH is detected. The signal of the PH detector is collected as operation data.
When the value is out of the predetermined range, the supply of the approximately saturated aqueous solution of slaked lime and the carbonated water is stopped. Of course, when the pH of the reformed water is out of the predetermined range, the control valve provided in the carbonated water supply pipe is controlled instead of the method of stopping the supply of the substantially slaked lime and the carbonated water as described above. Is preferred. That is, in such a tap water reforming apparatus, slaked lime and free carbonic acid contained in carbonated water undergo a neutralization reaction to generate calcium hydrogen carbonate, and the tap water is reformed. When the amount of free carbonic acid is small relative to the supplied amount, the neutralization reaction is completed early, and the PH increases without sufficient improvement of the Langeria index. On the other hand, if the amount of free carbonic acid is too large, corrosive carbonic acid remains in the reformed water, which is not preferable. Therefore, the signal (on / off signal) from the liquid level gauge is set so that the supplied amount of carbonated water containing free carbonic acid is slightly smaller than the required supply amount, and reformed in the receiving tank. The PH of the reformed water is measured by a PH detector, and a control valve provided in the carbonated water supply pipe is controlled by the signal to adjust the supply amount of the carbonated water. A prescribed range (PH5.
8 to 8.6). According to such a configuration, the reforming water in each of the water receiving tanks is simultaneously operated via the unit water supply pipe by the water supply device arranged in the main water supply pipe, or the manual open / close valve provided in the unit water supply pipe is operated as necessary. By doing so, only the reformed water in one of the water receiving tanks is sent to the place of use. Therefore, the size and the size of the apparatus can be reduced as compared with the case where a water supply apparatus and a water supply pipe having a PH detector are provided in each of the water receiving tanks. And when this water receiving tank is arranged at a relatively large distance (for example, 200 m or more), the slaked lime substantially saturated aqueous solution produced in the slaked lime dissolving tank is supplied to the intermediate tank by another liquid feeding device,
Here, it is preferable to be configured so as to be temporarily stored and then supplied to a water receiving tank via an aqueous solution injection device. In this case, a main water supply pipe having a water supply device is connected to each of the water receiving tanks, and a return pipe for reforming water having a pump and a PH detector is provided in each of the water receiving tanks.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a tap water reforming apparatus according to the present invention will be described below with reference to FIGS. In FIG. 1, reference numeral 1 denotes a slaked lime dissolving tank in which a stirrer 2 is installed. Slaked lime a is charged into the slaked lime dissolving tank 1 and a part of tap water W is supplied from a first water supply pipe 4 having a water supply valve 3. ₁ is supplied,
Here slaked substantially saturated aqueous solution W ₂ is produced. Water valve 3
Is operated by a signal from a liquid level gauge (not shown) provided in the slaked lime dissolving tank 1. 5 is the melting residue d
It is a discharge pipe for discharging. The slaked lime dissolving vessel slaked lime substantially saturated aqueous solution W ₂ produced by 1, two water tank 7a through the solution feed pipe 6, are supplied to 7b. That is, the aqueous solution supply pipe 6 includes a main pipe 6a and a branch pipe 6b, and the main pipe 6a and the branch pipe 6b are provided with injection pumps 8a and 8b as an aqueous solution injection apparatus, respectively. The infusion pump 8a, 8b is metered is selected in order to simplify the control may be a variable displacement type, the control device 10a, configured to be operated by the control signal V ₁ ~V ₄ from 10b. More specifically, the water receiving tanks 7a and 7b
V5, V5 from lower level gauges 9c, 9d provided in
6 the control unit 10a, is input to the 10b where control signal _V 1, _{V 2} is created, slaked lime substantially saturated aqueous solution _{W 2} by operating the infusion pump 8a, 8b by the control signal _V 1, _{V 2} Is supplied to the water receiving tanks 7a and 7b. The upper level gauge 9 when the liquid surface WL reaches the upper liquid surface WL ₂
a, signal _V 7, _{V 8} from 9b the control device 10a, 10
b, the control signals V ₃ and V ₄ are output, and the infusion pumps 8a and 8b are stopped. In this embodiment, different aqueous solution supply pipes having injection pumps 8a and 8b as an aqueous solution injection device are constituted by the main pipe 6a and the branch pipe 6b, but these may be arranged in parallel as required. . On the other hand, 11 is a free carbon dioxide concentration adjusting device,
The free carbonic acid concentration adjusting device 11 includes a free carbonic acid
And a gas pipe 16 having a control tank 15 and a second supply pipe 17. And the amount of free carbonic acid in which a part of the tap water W ₃ included in the mixing tank when 14 is supplied into the tap water W ₃ of the portion from the second supply pipe 17 is measured by the free carbon dioxide concentration meter 12, the signal V ₉ is guided to the control valve 15, the control valve 1
5 is operated to inject the carbon dioxide gas C in the carbon dioxide gas cylinder 13 into the tap water W ₃ in the mixing tank 14 via the gas pipe 16 so that the carbonated water W ₄ having a predetermined free carbon dioxide concentration is produced. Has become. Although in this free carbon dioxide concentration adjusting device 11 has to be mixed with tap water W ₃ carbon dioxide C in the mixing tank 14 may be mixed using a line mixer instead. Thus carbonated water W ₄ that is manufactured, the water tank 7a through carbonated water supply pipe 18,
7b. Specifically, the carbonated water supply pipe 18 includes a main pipe 18a and a branch pipe 18b.
8a and the branch pipe 18b and the respective control valves 19a, 19b are provided, the control valve 19a, 19b, the control signal _{V 1} of the from the controller 10 the infusion pump 8a, like the 8b
It is controlled by ~V _4. Also in this case, the different carbonated water supply pipes 18 having the control valves 19a and 19b are constituted by the main pipe 18a and the branch pipe 18b, but the main pipes 18a may be arranged in parallel instead.
In this way slaked substantially saturated aqueous solution W ₂ and receiving tank 7a where the carbonated water W ₄ is supplied, the 7b such as FM valve the valve body 2
The third water supply pipes 21a and 21b each having the first and second valve bodies 20a and 20b are connected to the control devices 10a and 1b.
And it is controlled by a control signal _V 1 ~V ₄ from 0b. The valve body 20a, by opening 20b the third water supply pipe 21a, the tap water _{W 5} which is a raw water from 21b are supplied to the receiving tank 7a, a 7b. Thus, slaked lime almost saturated aqueous solution W ₂
Reforming water W by the tap water W _5, which is a carbonated water W ₄ and the raw water and
₆ is manufactured. Reference numerals 22a and 22b denote unit water pipes having manually opened and closed valves 23a and 23b, respectively. One ends of the unit water pipes 22a and 22b are respectively connected to water tanks 7a and 7b.
The other end is a water pump 2 as a water supply device
5 is connected to a main water supply pipe 26 having the same. 28 is a return tube of the reforming water W _6, together with the return pipe 28 has one end connected to the upstream side of a by and water pump 25 primarily water pipe 26 and the other end connected to a water tank 7a Have been. The return pipe 28 is provided with a pump 29 and a PH detector 30. Reference numeral 31 denotes an apartment house where the reformed water W6 is used. Receiving tank 7a, but returned to the water tank 7a through the return pipe 28 from the main water supply pipe within 26 by the pump 29 is part of the reforming water W ₆ produced within 7b signal V from PH detector 30 at this time ₁₀ is the control device 10
a, it is inputted to 10b, where it is compared with the PH value of the predetermined range which is previously input to the storage device while being collected as operational data, PH value of the reforming water W ₆ is out of a predetermined PH value In this case, an alarm is issued if necessary, and signals V ₂ and V ₄ are output and at least the infusion pump 8
a, 8b and the control valve 19a, by manipulating the 19b to stop supplying the water receiving tank slaked substantially saturated aqueous solution _{W 2} and carbonated water _{W 4.} And preferably, the signal V of the PH detector 30
_The control signal 10 is input to the control devices 10a and 10b to obtain a supply amount of carbonated water for obtaining a predetermined PH, a control signal as a proportional signal is separately created, and the control valves 19a and 19b are controlled by the control signals V ₁₁ , V and ₁₂ . by controlling the 19b, it is possible to produce _a suitable reforming water W ₆ consecutively. The reforming water W ₆ being capable of water in collective housing 31 is a point of use through the unit water lines 22a, 22b and the main water pipe 26 by operating the water pump 25. Thus water receiving tank 7a, when the reforming water W ₆ in 7b to water to collective housing 31 the liquid level WL is lowered. When this liquid surface WL reaches the lower liquid level WL ₁ lower level gauge 9c, signal _V 5, _{V 6} from 9d is emitted, the signal V as described above
₅ and control signals V ₁ and V ₂ based on V ₆ , the injection pumps 8 a and 8 b provided on the main pipe 6 a as the aqueous solution supply pipe 6 and the branch pipe 6 b, and the main pipe 17 as the carbonated water supply pipe 17.
a, control valves 18a, 18b provided in branch pipe 17b
Receiving but has furthermore a third water supply pipe 21a, the valve element 20a provided in 21b, 20b is operated slaked substantially saturated aqueous solution _{W 2,} the tap water _{W 5} which is a carbonated water _{W 4} and the raw water at a predetermined ratio aquarium 7a, is supplied into 7b produces a reformed water _{W 6.} The water tank 7a, the liquid level WL of 7b reaches the upper liquid surface WL ₂ Top Level gauge 9a, signal _V 7, _{V 8} is emitted from 9b, infusion pumps 8a, stops the 8b control valve 19a, 19b and valve bodies 20a, 20
b is closed. Of course in this case, to create a control signal _V 1 ~V ₄ the signal _{V 10} from PH detector 30, the control signal _V 1 ~V ₄ a proportional signal and without lime substantially saturated aqueous solution W
It is conceivable to control the supply amounts of ₂ , carbonated water W ₄ , and tap water W _5. However, since the control system becomes complicated, this signal V
₁ ~V ₄ on-off signals and without injection based on the feed rate per hour of the pre-set tap water W ₅ pumps 8a, 8b
Aqueous lime substantially due to saturation _{W 2} and the control valve 19a, 19
good idea to set the supply amount of carbonated water W ₄ by b. The supply amount of this carbonated water W ₄ is better to previously set to be slightly smaller supply amount than the predetermined feed amount determined by experiments. The PH of the reforming water W ₆ is to exceed the predetermined value when the contingency, for example, the supply amount of tap water W ₅ supply amount is small, or hydrated lime substantially saturated aqueous solution of was increased. Only the control signal V when the or necessary to stop the supply of slaked lime substantially saturated aqueous solution and carbonated water as described above such case PH of the reforming water W ₆ exceeds Tokoro stationary
_11, to create a _{V 12,} the control signal _{V 11, V 12} a control valve 19a as a proportional signal, receiving tank 7a more carbonated water _{W 4} by controlling the 19b, is supplied to 7b reforming water W
_It lowers the PH value of ₆ . In addition, each water receiving tank 7
a or 7b, the on-off valve 23a
Or 23b closed by manually operating the so that the stop water supply of the reforming water W ₆ of the water receiving tank 7a or in 7b to clean. In this embodiment, the case where two control devices 10a and 10b are provided is shown, but of course, the control devices 10a and 10b
10b may be one group. FIG. 2 is a system diagram showing another embodiment of the tap water reforming apparatus according to the present invention, and the same reference numerals as those in FIG. 1 denote the same names. This embodiment is suitable when the distance L between the water receiving tank 7a and the water receiving tank 7b is relatively long (for example, 200 m or more), and the slaked lime dissolving tank 1 and the free carbon dioxide concentration adjusting device 11 are connected to one of the receiving tanks. Water tank 7a
It is arranged near. The water tank 7a particular slaked substantially saturated aqueous solution W ₂ produced by slaked lime dissolving vessel 1, through the main pipe 6a constituting the aqueous solution feed pipe 6 by means of an infusion pump 8a
In addition, the centrifugal pump 32 which is a liquid feeding device is operated, and another water receiving tank 7b is formed by the branch pipe 6b constituting the aqueous solution supply pipe 6.
Is supplied to an intermediate tank 33 arranged near the tank, and once stored therein, is supplied to the water receiving tank 7b by an injection pump 8b. The centrifugal pump 32 is configured to be operated by a signal from, for example, a ball tap type liquid level meter provided in the intermediate tank 33. In this case, return pipes 28a, 28 having PH detectors 30a, 30b and pumps 29a, 29b are respectively provided in the water receiving tanks 7a, 7b.
b connected, each receiving tank 7a, P of the reforming water _{W 6} in 7b
H is detected. By operating the water pumps 25a and 25b, each of the water receiving tanks 7 is operated.
a, Housing 31a reforming water _{W 6} in 7b, so that the can be supplied to 31b. Carbonated water W ₄ produced by free carbon dioxide concentration adjusting device 11 in this embodiment also an intermediate tank is provided in water receiving tank 7b vicinity may be supplied from the intermediate tank receiving tank within 7b but, naturally carbonated water W ₄ Has the same pressure as ordinary tap water, and does not particularly require an intermediate tank. In the above embodiment, the valve bodies 20a, 20
b is the upper level gauge 9a provided in each of the water receiving tanks 7a, 7b,
9b and the lower level gauge 9c, was to be controlled by the signal _V 1 ~V ₄ based on the signal _V 5 ~V ₈ from 9d, the valve body 20a, if the 20b and FM valve, the signal _{V 1}
Control by ~V ₄ it is clear that not required.

[0006]

As is apparent from the above description, according to the tap water reforming apparatus according to the present invention, one slaked lime dissolving tank and a free carbon dioxide concentration adjusting device are used to mix a substantially saturated aqueous slaked lime aqueous solution with a carbonate having a predetermined free carbon dioxide concentration. Since water is produced and the substantially saturated aqueous solution of slaked lime and carbonated water are supplied to two or more water receiving tanks to reform tap water, especially in existing apartment houses having a plurality of water receiving tanks, etc. The predetermined water quality can be improved with a small device. As a result, there is a great advantage that the installation area of the apparatus can be reduced and the manufacturing cost and operation cost of the apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an embodiment of a tap water reforming apparatus according to the present invention.

FIG. 2 is a system diagram showing another embodiment of the tap water reforming apparatus according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Slaked lime dissolution tank 4 First water supply pipe 2 Stirrer 5 Discharge pipe 3 Water supply valve 6 Aqueous solution supply pipe 7a, 7b Water receiving tank 18 Carbonated water supply pipe 8a, 8b Injection pump 20a, 20b
Valve body 9a, 9b Upper level gauge 21a, 21b
Third water pipe 9c, 9d Lower level gauge 22a, 22b
Unit water pipe 10 Control device 23a, 23b
Open / close valve 11 Free carbon dioxide concentration controller 25 Water pump 12 Free carbon dioxide meter 26 Main water pipe 13 Carbon dioxide gas cylinder 28 Return pipe 14 Mixing tank 29 Pump Reference Signs List 16 gas pipe 32 centrifugal pump 17 second water supply pipe 33 intermediate tank

Claims (5)

[Claims] 1. A slaked lime dissolving tank for producing an almost saturated aqueous solution of slaked lime by mixing a part of tap water and slaked lime, and a carbonated water having a predetermined free carbonic acid concentration by injecting carbon dioxide into a part of the tap water A free carbonic acid concentration adjusting device, and at least two or more water receiving tanks for mixing the carbonated water and tap water as raw water to form a reformed water by mixing the slaked lime substantially saturated aqueous solution with the tap water as raw water. Each of the receiving tanks is connected with a different aqueous solution supply pipe having an aqueous solution injection device, and
A tap water reforming device, wherein the free carbon dioxide concentration adjusting device and each of the receiving tanks are connected by different carbonated water supply pipes each having a control valve, and a tap water supply pipe as raw water is connected to each of the receiving tanks. Quality equipment. 2. A water level gauge is provided in each water receiving tank, and tap water which is raw water supplied to each water receiving tank by a signal of the liquid level gauge;
2. The tap water reforming apparatus according to claim 1, wherein a supply amount of the substantially saturated aqueous solution of slaked lime and the carbonated water is controlled. 3. The water supply according to claim 1, wherein one end of each unit water pipe is connected to each water receiving tank, and the other end of each unit water pipe is connected to a main water pipe having a water supply device. Water reformer. 4. The tap water reforming apparatus according to claim 1, wherein a main water supply pipe having a water supply device is connected to each of the water receiving tanks. 5. One end of a return pipe for reforming water having a pump and a PH detector is connected to the main water supply pipe and upstream of the water supply device, and the other end of the return pipe is connected to a water receiving tank. 4. The tap water reforming apparatus according to claim 3, wherein