JP2979891B2 - Dissolved oxygen concentration reduction system in deaerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for reducing the concentration of dissolved oxygen in a deaerator applied to a water supply line to a boiler or other thermal equipment, a building, an apartment, or the like.

[0002]

2. Description of the Related Art As is well known, a deaerator for preventing internal corrosion of cooling and heating equipment such as a boiler, a water heater or a cooler is incorporated in a water supply line for such equipment. In recent years, a deaerator has been used as a measure for preventing red water in a water supply / distribution pipe in a building such as a building or an apartment. In this deaerator, as shown in FIG. 3, a membrane type deaeration module 22 is connected in a water supply line 21 to equipment used, and raw water (tap water, well water, other industrial water, etc.) is provided in the deaeration module 22. In this process, the inside of the degassing module is evacuated by a water-sealed vacuum pump 23 to degas and remove dissolved gases in the raw water. In the figure, reference numeral 24 denotes a deaerated water tank.

As shown in FIG. 2, in the deaerator, if the amount of treated water is constant, the lower the temperature of the supplied raw water, the higher the dissolved oxygen concentration of the treated water. On the other hand, if the raw water temperature is constant, the dissolved oxygen concentration decreases as the amount of treated water decreases. Therefore, the dissolved oxygen concentration is low in summer when the water temperature is high, and the dissolved oxygen concentration is high in winter when the water temperature is low.Therefore, even in the degassed water treated by the deaerator, the dissolved oxygen concentration varies depending on the raw water temperature. This is a problem, and in cold climates, etc., the deaerator must be increased in size.

[0004]

DISCLOSURE OF THE INVENTION In view of the above problems, the present invention adjusts the supply amount of raw water by adjusting the load state of the degassed water supply destination (the amount of degassed water used) and adjusts the concentration of dissolved oxygen in the degassed water. It is an object of the present invention to provide a system for reducing the pressure.

[0005]

That is, the present invention relates to a deaeration apparatus having a deaeration module connected to a water supply line between a raw water supply section and a deaeration water tank. Inside, a plurality of water level responding means that operates stepwise according to the water level is provided, and the flow rate of the supply water passing through the deaeration module is adjusted for each operation range of each means, and the deaerated water is supplied to the deaerated water tank. It is characterized in that it is supplied continuously.

[0006]

According to the present invention, the plurality of water level response means provided in the degassed water tank are operated stepwise according to the outflow amount (used amount) of the degassed water, and are preset for each operation range. Since a small amount of degassed water is supplied, when the amount of outflow is small, degassed water having a low dissolved oxygen concentration can be supplied.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an arrangement of each device in a water supply line 6 of a deaeration device embodying the present invention, and a deaeration water tank 2.
A plurality of water level responding means provided in, for example, ball tap 3,
It is explanatory drawing which shows the relationship of 4,5. A pressure reducing valve 7 and a deaeration module 8 are inserted between the raw water supply section 1 and the deaeration water tank 2 of the water supply line 6, and the deaeration module 8 is provided with a water seal type through a vacuum deaeration line 10. The vacuum pump 9 is connected. The water sealed by the water-sealed vacuum pump 9 is supplied via a sealed water supply line 11 branched from a predetermined location on the upstream side of the pressure reducing valve 7 provided in the water supply line 6. Discharged via line 12.

The degassing module 8 includes, for example, a large number of hollow fiber membranes. In a process in which raw water is passed through the inside of the hollow fiber membrane and a vacuum is drawn outside the hollow fiber membrane, water passes through the hollow fiber membrane. A hollow fiber membrane degassing module for removing dissolved oxygen in raw water, wherein the pressure reducing valve 7 prevents the supply water pressure above a certain level from being applied to the degassing module 8 and prevents the degassing module 8 from being damaged. Is being planned. In the figure, reference numeral 13 denotes a constant flow valve provided in the sealed water supply line 11, and reference numeral 14 denotes an electromagnetic valve. Reference numeral 15 denotes a solenoid valve provided in the vacuum degassing line 10.

As shown in FIG. 1, the system for reducing the concentration of dissolved oxygen in degassed water according to the present invention is provided at one end in the degassed water tank 2 at predetermined intervals in the vertical direction from the lower side. , A first ball tap 3, a second ball tap 4, and a third ball tap 5 are inserted and the ends of the ball taps are connected to the water supply line 6. In the figure, reference numeral 16 denotes a deaerated water supply line. Then, the rated treated water amount of the degassing module 8 is, for example,
Assuming that the treated water volume of 25 ° C. is 1000 l / hr (see FIG. 2) for treating deaerated water having a dissolved oxygen concentration of 0.5 PPM, when the valve is opened through the first, second, and third ball taps, The amount of water is defined as the rated treated water amount (100%), and the amount of water passing through each ball tap is set to approximately 35% of the rated treated water amount. In the figure, reference numeral 17 denotes the upper limit position of the third ball tap 5.

Next, the operation of the dissolved oxygen concentration lowering system will be described. Incidentally, for example, also in a boiler or a building water supply system for supplying degassed water, the amount of degassed water used varies depending on the time zone and the load is not constant. Therefore, in the dissolved oxygen concentration lowering system of the present invention, raw water is supplied according to the outflow amount of degassed water, and degassed water having a lower dissolved oxygen concentration is supplied. That is, after storing deaerated water to a predetermined water level of the deaerated water tank 2 (when the third ball tap 5 is closed), the water ring vacuum pump is stopped. Thereafter, a load is generated at the supply destination, the deaerated water flows out through the deaerated water supply line 16, and the water level in the deaerated water tank 2 decreases, and the third
At the same time that the ball tap 5 is opened, the water-sealed vacuum pump 9 is driven via a line (not shown) to supply deaerated water into the deaerated water tank 2 via the deaeration module 8. However, the amount of flowing water when the third ball tap 5 is opened is about 3 times the rated treated water amount of the degassing module 8.
Since it is set to 5%, as shown in FIG. 2, the dissolved oxygen concentration in the degassed water is significantly lower than the predetermined concentration (0.5 PPM).

When the supply amount of the degassed water increases and the water level in the degassed water tank 2 decreases to open the second ball tap 4, the supply of the degassed water from the degassing module 8 is performed. The amount increases to about 70% of the rated treated water amount, and the dissolved oxygen concentration increases by the increase. Then, when the supply amount of the degassed water further increases and the first ball tap 3 is opened, the degassing module 8 supplies the degassed water with the 100% rated treated water amount to the degassed water tank 2. As described above, the first, second,
Since the third ball taps open in accordance with the supply amount of deaerated water, the deaerated water having a low dissolved oxygen concentration is supplied when the load is small, and the deaerated water stored in the deaerated water tank 2 is supplied. Can be reduced as a whole.
When the load decreases and the water level in the deaerated water tank 2 rises, each of the ball taps sequentially closes to store deaerated water having a low dissolved oxygen concentration in the deaerated water tank 2.

[0012]

As described above, according to the present invention, a plurality of water level responding means are provided in the degassing water tank, which operate stepwise according to the water level, and are set in advance for each operating range of each means. Since the amount of degassed water is supplied to the degassed water tank, degassed water having a low dissolved oxygen concentration corresponding to the load can be supplied. Therefore, when the load is small, supply degassed water with low dissolved oxygen concentration to reduce the dissolved oxygen concentration of the entire degassed water stored in the degassed water tank, and keep the rated dissolved Deaerated water having an oxygen concentration or less can be supplied to the load. In addition, even in a place where the temperature of raw water is low, such as in a cold region, if this dissolved oxygen concentration reduction system is adopted, it is economical without having to increase the size of the deaerator.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an arrangement of each device of a deaerator and a dissolved oxygen concentration reduction system embodying the present invention.

FIG. 2 is a diagram showing the relationship between the temperature of raw water, the concentration of dissolved oxygen in treated water, and the amount of treated water in the deaerator of FIG.

FIG. 3 is an explanatory diagram showing an arrangement of each device of a conventional deaerator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Raw water supply part 2 ... Deaerated water tank 3 ... 1st ball tap 4 ... 2nd ball tap 5 ... 3rd ball tap 6 ... Water supply line 8 ... Deaeration module 9 ... Water ring vacuum pump

Claims (1)

(57) [Claims] 1. A deaerator having a configuration in which a deaeration module 8 is connected to a water supply line 6 between a raw water supply unit 1 and a deaeration water tank 2. A plurality of water level response means 3, 4 and 5 which operate stepwise in accordance with each other are provided, and the flow rate of the supply water passing through the deaeration module 8 is adjusted for each operation range of each means so that the deaeration water A system for reducing the concentration of dissolved oxygen in a deaerator, wherein the system is continuously supplied to a tank 2.