JP3704744B2 - Membrane deaerator - Google Patents

Description

[0001]
[Industrial application fields]
The present invention accommodates a membrane module in a pressure-resistant vessel, the inside of the vessel is divided into a water supply unit and a decompression unit by the membrane module, a water-sealed vacuum pump in the decompression unit, and city water and industrial water at the inlet of the water supply unit The present invention relates to a membrane deaeration device in which a drain pipe for deaerated water is connected to an outlet of a raw water supply pipe and a water supply unit.
[0002]
[Prior art]
In order to know the deaeration performance of the membrane deaerator, that is, the deaeration rate, measure the dissolved oxygen (DO) concentration of raw water supplied to the membrane module and the DO concentration of deaerated water drained from the membrane module,
Deaeration rate = (Raw water DO concentration−Deaerated water DO concentration) / Raw water DO concentration must be compared or checked to see if it satisfies the standard value. For this reason, conventionally, a dissolved oxygen concentration meter is connected to each of the raw water supply pipe and the deaerated water discharge pipe.
[0003]
[Problems to be solved by the invention]
As described above, the conventional membrane deaerator requires two dissolved oxygen meters.
[0004]
[Means for Solving the Problems]
Therefore, the present invention provides a membrane deaerator comprising a membrane module having an interior divided into a water supply unit and a decompression unit by a deaeration membrane, and a vacuum pump that decompresses the decompression unit in the membrane module. A raw water supply pipe and a deaerated water drain pipe are connected to the membrane module, a branch pipe having an open / close valve is connected to each of the water feed pipe and the drain pipe, and both branch pipes are used as a supply pipe to the dissolved oxygen concentration meter. Connected, and provided a storage tank on the outlet side of the dissolved oxygen concentration meter, connected to the storage line of the seal water of the vacuum pump to the storage tank, the raw water in the water supply pipe and the circulation line in the circulation line A heat exchanger that performs heat exchange with the sealing water is provided .
[0005]
【Example】
In the illustrated embodiment, 1 is a pressure vessel, 2 is a membrane module having a deaeration membrane that is housed in a pressure vessel and divides the inside of the vessel into a water supply part 1a and a pressure reduction part 1b, and 3 is a pipe 4. A water-sealed vacuum pump connected to the pressure reducing part 1b of the pressure vessel, 5 is a water supply pipe including a water supply pump 6 for supplying raw water from the makeup water tank to the inlet of the water supply part of the pressure vessel, and 7 is the water supply part 1a. The drain pipe for taking out deaerated water from an outlet is shown.
[0006]
The pressure vessel is composed of two parts, a front stage 1-I and a rear stage 1-II, in which the outlet of the water supply unit and the inlet of the water supply unit are connected in series by the connecting pipe 8, and the vacuum pump 3 is connected to the decompression unit of each pressure vessel. The water supply pipe 5 is connected to the inlet of the water supply section of the front pressure vessel 1-I, and the drain pipe 7 is connected to the outlet of the water supply section of the rear pressure container 1-II.
[0007]
A sealing water circulation line 9 is connected to the vacuum pump 3 in order to circulate and use the sealing water. A small storage tank 10 and a heat exchanger 11 are provided in the middle of the circulation line.
The middle of the water supply pipe 5 from the water supply pump 6 is connected to the inlet end of the cooling pipe 12 piped in the heat exchanger, and the remainder of the water supply pipe 5 toward the water supply part of the pressure vessel at the previous stage is the cooling pipe. 12 outlet ends are connected.
[0008]
Thus, the pumps 3 and 6 are operated, the vacuum pump 3 generates a negative pressure in the pressure vessel, and the gas containing the water vapor gas in the raw water supplied to the water supply portion of the pressure vessel passes through the membrane module to reduce the pressure. Then, it can be sucked into a vacuum pump, thus treating the raw water into degassed water, and supplying the degassed water from the drain pipe 7 to a necessary place such as a boiler.
[0009]
During the operation of the vacuum pump, the seal water circulates through the circulation line 9 through the storage tank 10 and the heat exchanger 11, and is cooled by the raw water flowing through the cooling pipe 12 when passing through the heat exchanger 11. Further, the vacuum pump sucks into the decompression section, and the bubbles mixed with the seal water are exhausted from the storage tank 10.
[0010]
A first branch pipe 13 having an on-off valve V1 is connected to the water supply pipe 5. The drain pipe 7 is connected to a second branch pipe 14 having an on-off valve V2. Both branch pipes 13 and 14 are connected to a supply pipe 16 leading to the dissolved oxygen concentration meter 15, and the water that has passed through the dissolved oxygen meter 15 flows out into the seal water storage tank 10 through the pipe 17.
[0011]
Therefore, when the on-off valve V1 is opened during the operation of the above-described membrane deaerator (the on-off valve V2 is kept closed), a part of the raw water flowing through the water supply pipe 5 is supplied to the first branch pipe 13. The dissolved oxygen concentration meter 15 is supplied to the dissolved oxygen concentration meter 15 through the pipe 16 and flows out into the storage tank 10 to measure the dissolved oxygen concentration in the raw water. When the on-off valve V2 is opened (the on-off valve V1 is kept closed), a part of the deaerated water flowing through the drain pipe 7 passes through the second branch pipe 14 and the supply pipe 16 and the dissolved oxygen concentration meter 15. The dissolved oxygen concentration in the deaerated water is measured by flowing out into the storage tank 10.
[0012]
【The invention's effect】
As is apparent from the above, according to the present invention, a single dissolved oxygen concentration meter 15 is used to measure the DO concentration of raw water and the DO concentration of degassed water by switching the open / close valves V1 and V2. The deaeration performance of the apparatus can be obtained.
[Brief description of the drawings]
FIG. 1 is a system diagram of an embodiment of a membrane degassing apparatus of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Pressure-resistant container 1a Water supply part 1b Pressure reducing part 2 Membrane module 3 Sealed vacuum pump 5 Raw water supply pipe 6 Water supply pump 7 Deaerated water drain pipe 13 First branch pipe 14 Second branch pipe 15 Dissolved oxygen concentration meter 16 Dissolved Supply pipe to oxygen concentration meter V1 First on-off valve V2 Second on-off valve

Claims (1)

In a membrane deaerator comprising a membrane module whose interior is divided into a water supply unit and a decompression unit by a deaeration membrane, and a vacuum pump for decompressing the decompression unit in the membrane module ,
A raw water supply pipe and a deaerated water drain pipe are connected to the membrane module, a branch pipe having an open / close valve is connected to the water feed pipe and the drain pipe, and both branch pipes are supplied to a dissolved oxygen concentration meter. A storage tank is provided at the outlet side of the dissolved oxygen concentration meter, a circulation line for sealing water of the vacuum pump is connected to the storage tank, and the raw water in the water supply pipe and the circulation line are in the middle of the circulation line A membrane deaerator having a heat exchanger for exchanging heat with the sealing water .

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