JP2556399Y2 - Corrosion prevention device for hot water supply piping - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a corrosion preventing device for a hot water supply pipe.

[0002]

2. Description of the Related Art The generation of red water in a hot water supply pipe is caused by red rust caused by corrosion of a piping system, and various chemical or physical methods have been implemented as red water prevention measures. For example, there is a method of adding a rust inhibitor to the water supply, but this method requires less construction cost to provide a rust inhibitor addition device, and the construction period is short, but running costs are high, Since it is used as domestic water, special consideration must be given to the rust inhibitor component in terms of safety.
In addition, as the pipe rehabilitation method, slaked lime injection method,
There are various methods such as the ozone method, but they require a lot of cost and a long construction period, and if rehabilitation is incomplete, there is a risk of red water re-generation.

[0003] Therefore, in recent years, a pipe corrosion prevention apparatus using a membrane type deaerator which is high in safety and low in cost has been adopted. For example, a piping configuration as shown in FIGS. 5 and 6 is adopted. In both figures, the basic configuration includes a makeup water tank 2, a hot water boiler 5, a hot water storage tank 6, a water supply pump 7, and a water supply pump. Line 8, hot water storage line 9,
It comprises a makeup water line 10, a load 11, a hot water supply pump 12, a hot water supply line 13, a return line 14, a relief line 15, and a membrane type deaerator 20. Thus, FIG.
In the piping configuration shown in FIG. 1, a membrane type deaerator 20 is provided at an upstream position of the makeup water tank 2, a water level detection sensor 30 is provided in the makeup water tank 2, and a signal from the water level detection sensor 30 is used to supply makeup water. The supply of water to the tank 2 and the operation of the membrane deaerator 20 are controlled. 6, the makeup water circulation line 31 is connected to the makeup water tank 2, and the membrane deaerator 20 is inserted into the makeup water circulation line 31. The operation of the membrane deaerator 20 is controlled according to the deaeration state.

[0004]

However, the above-mentioned two piping configurations have the following problems. In the piping configuration shown in FIG. 5, if the membrane of the membrane type deaerator 20 is clogged, there is a risk of water cutoff, and it is necessary to provide an automatic emergency bypass mechanism 32 in consideration of safety.
In addition, there is a problem that the installation location of the membrane type deaerator 20 is limited to the rooftop, and it takes much time to perform the construction. Further, a large-sized membrane deaerator 20 having a certain capacity is required so that the maximum flow rate of the makeup water can be processed. In addition, even in the piping configuration shown in FIG. 6, the installation location of the membrane deaerator 20 is limited to the roof, and the construction takes time. In addition, the make-up water tank 2 stores deaerated water, and it is necessary to continuously supply deaerated water to a sufficiently low level when the maximum amount of water is used. .

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and can be easily constructed at a low cost. It is an object of the present invention to provide a corrosion prevention device capable of responding. Specifically, a hot water boiler and a hot water storage tank are connected by a hot water storage line and a water supply line, and an upstream position of a water supply pump in the water supply line and makeup water are connected. In a hot water supply pipe configuration, a tank and a makeup water line are connected, the hot water storage tank and the load are connected by a return line and a hot water supply line, and the hot water storage tank and the makeup water tank are connected by a relief line,
A water storage tank is inserted into the makeup water line, a circulation line is connected to the water storage tank, and a circulation pump and a membrane deaerator are inserted into the circulation line.

[0006]

According to this invention, water (degassed water) from which dissolved gas (dissolved oxygen) has been removed by a membrane deaerator is stored in a water storage tank, and the degassed water (degassed water) is removed according to the use of hot water. Oxygen water) to the hot water boiler, water storage tank, and piping connected to these. This allows the degassed water to flow through the hot water supply piping system,
Corrosion in hot water supply piping is reliably and continuously prevented.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. In FIG. 1, a makeup water tank 2
Are arranged as an expansion tank (cistern tank) or an elevated water tank installed on the roof of a building or the like. The hot water boiler 5 and the hot water storage tank 6 are connected by a hot water storage line 9 and a water supply line 8 into which a water supply pump 7 is inserted.
It forms a circulation path. An upstream position of the water supply pump 7 in the water supply line 8 and the makeup water tank 2 are connected by a makeup water line 10. A load 11 using hot water such as a shower or a curan and the hot water storage tank 6 are connected to a return line 14 and a hot water supply line 1 into which a hot water supply pump 12 is inserted.
3 and form a circulation path. The hot water storage tank 6 and the makeup water tank 2 are connected by a relief line 15.

A water storage tank (buffer tank) 1 for storing deaerated water (deoxygenated water) is inserted into the make-up water line 10. The raw water from the make-up water tank 2 is supplied to the water storage tank 1. A circulation line 3 as a line for degassing is connected. In the circulation line 3, a membrane type deaerator 20 and a circulation pump 4 are inserted. The membrane type deaerator 20 includes a deaeration module 21 and a vacuum pump 22 for vacuum-suctioning a dissolved gas (dissolved oxygen) in raw water through the deaeration module 21.

FIG. 2 shows a detailed example of the membrane deaerator 20. In FIG. 2, a deaeration module 21 using a hollow fiber gas permeable membrane or the like has a water-sealed vacuum pump on the outer periphery of the gas permeable membrane. A vacuum is established at 22 so that the dissolved gas of the raw water flowing through the gas permeable membrane is removed through the gas permeable membrane. Then, the membrane deaerator 20 in this embodiment is used.
Are a pressure reducing valve 23, a constant flow valve 24, and solenoid valves 25 and 26.
And a flow switch 27 is further provided. This flow switch 27 is controlled by the output signal.
It works to control the operation of the vacuum pump 22 and the opening and closing of the solenoid valves 25 and 26. That is, when raw water flows in the degassing module 21, the flow switch 27 is operated to turn on the vacuum pump 22 and open the two solenoid valves 25 and 26.

In the above configuration, when hot water is used at the load 11, degassed (deoxygenated) water is supplied from the water storage tank 1 to the hot water boiler 5 by the amount used, and the water is supplied accordingly. Raw water flows into the water storage tank 1 from the water tank 2. Then, the circulation line 3 connected to the water storage tank 1
The inside circulation pump 4 operates to circulate the water in the water storage tank 1 to the inside of the membrane deaerator 20 to remove dissolved gas in the water. As a specific operation control method of the circulation pump 4 and the membrane deaerator 20, a method of operating the circulation pump 4 and the membrane deaerator 20 by timer control in conjunction with the supply of water to the water storage tank 1. Alternatively, there is a method of detecting the dissolved oxygen concentration of water in the water storage tank 1 and operating the circulation pump 4 and the membrane deaerator 20 so that the value becomes equal to or less than a set value.

The performance curve of a general membrane deaerator is shown in FIG.
When the amount of treatment increases, the dissolved oxygen concentration in the treated water also increases, and it becomes impossible to sufficiently remove dissolved oxygen in the raw water. Therefore, usually, when selecting the capacity of the membrane deaerator, taking into account the maximum water usage,
A large membrane deaerator with a certain capacity is selected. In this invention, however, the water storage tank 1 is provided. Can be fully supported. That is, as shown in the graph of FIG. 4, even if the amount of used water suddenly increases, the amount can be covered by the deaerated water stored in the water storage tank 1 (shaded portion in FIG. 4). Even if a relatively small-capacity membrane deaerator is used, water with a sufficiently low level of dissolved oxygen can be continuously supplied.

Further, in the present invention, the hot water is returned from the release line 15 to the make-up water tank 2 and may flow into the water storage tank 1, so that the temperature sensor 28 is provided in the water storage tank 1. This temperature sensor 28
When the water temperature in the water storage tank 1 becomes equal to or higher than the set temperature, a signal for stopping the supply of water to the membrane deaerator 20 is output. Therefore, damage of the degassing module 21 due to high heat can be prevented, and an inexpensive degassing module with low heat resistance can be used.

[0013]

As described above, according to the present invention, according to the use of hot water, water from which dissolved gas (dissolved oxygen) has been removed by a membrane deaerator is connected to a hot water boiler, a hot water storage tank, and the like. It can be sent to the piping system, and the corrosion in the hot water supply piping can be reliably and continuously prevented. Also,
There is no need to install on the roof of a building or the like where construction is complicated, and it can be easily installed near the ground with low construction cost.
Furthermore, by providing a storage tank for storing deaerated water in the make-up water line, the deaerator with a relatively small capacity (low processing capacity) can sufficiently cope with the maximum amount of water used. Moreover, implementation with a low-cost device is possible.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an embodiment of a corrosion prevention device according to the present invention.

FIG. 2 is a system diagram showing a detailed example of a membrane deaerator in the present invention.

FIG. 3 is a graph showing the performance of a general membrane deaerator.

FIG. 4 is a graph showing an example of a change in hot water supply amount.

FIG. 5 is a system diagram showing an example of a conventional corrosion prevention device.

FIG. 6 is a system diagram showing another example of a conventional corrosion prevention device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 water storage tank 2 makeup water tank 3 circulation line 4 circulation pump 5 hot water boiler 6 hot water storage tank 7 water supply pump 8 water supply line 9 hot water storage line 10 makeup water line 11 load 12 hot water supply pump 13 hot water supply line 14 return line 15 relief line 20 membrane type dewatering Pneumatic device 21 Deaeration module 22 Vacuum pump 28 Temperature sensor

Claims (1)

(57) [Scope of request for utility model registration] 1. A hot water storage boiler 5 and a hot water storage tank 6
In 9 and the water supply line 8
Between the upstream position of the water supply pump 7 and the makeup water tank 2
The hot water storage tank 6 and the load 11 are connected by a water supply line 10.
Are connected by the return line 14 and the hot water supply line 13 and
Release line for hot water storage tank 6 and make-up water tank 2
In the hot water supply piping configuration connected at 15, the makeup water line
The water storage tank 1 is inserted into the
1 is connected to a circulation line 3 and the circulation line 3 is connected to a circulation port.
A corrosion prevention device for a hot water supply pipe, wherein a pump 4 and a membrane deaerator 20 are inserted .