JP2014094350A - Vacuum deaeration apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum deaeration apparatus allowing reduction of installation and apparatus costs in installing a vacuum deaeration apparatus.SOLUTION: A vacuum deaeration apparatus utilizing a water head pressure includes a deaeration tower body which is provided with a packed layer of a gas-liquid contact material in its gas-tight inside, supplies to-be-treated water from above the packed layer and discharges treated water from a treated water discharge outlet under the packed layer and also discharges the inside gas by evacuating means, a connection pipe discharging the treated water from the treated water discharge outlet and a treated water tank having a water level of stored water lower than the lower part of the packed layer by a height H corresponding to the height or higher at which the vacuum of the deaeration tower body is kept with respect to the atmospheric pressure, with the water level set constant above the lower end of the connection pipe.

Description

  The present invention relates to a vacuum deaeration device using water head pressure, and more particularly to a space-saving, low-cost vacuum deaeration device using water head pressure that reduces the occupied volume and weight.

  Conventionally, highly pure water has been used in the semiconductor manufacturing field, the pharmaceutical manufacturing field, and the like. As equipment for producing such pure water, pretreatment equipment that removes suspended solids from raw water to prepare pretreated water, and ions, organic substances, dissolved gases, etc. are removed from pretreated water to obtain primary pure water. A pure water production facility including a primary pure water facility and a secondary pure water facility for further purifying the primary pure water is used. In this deionized water production facility, the produced deionized water is supplied to the use point, and the remaining portion not used at the use point is circulated to the primary deionized water tank installed at the rear stage of the primary deionized water facility via the return pipe. It is configured.

  In the primary pure water equipment of such pure water production equipment, a vacuum deaerator is used to remove dissolved gas in the water.

  FIG. 6 is a schematic view showing an example of a conventional vacuum degassing apparatus. As shown in the figure, this vacuum degassing apparatus has a structure in which an upright cylindrical deaeration tower body 1 is installed on a base provided on the ground, Is provided with a packed bed 2 filled with a gas-liquid contact material, and a treated water reservoir 3 is disposed therebelow. The water to be treated is supplied through a water supply pipe 5 provided with an automatic valve 41.

  The deaeration process is performed as follows. That is, the internal gas is sucked from above by the vacuum pump 6 to be in a reduced pressure state, and the water to be treated is poured from the nozzle 7 connected to the water supply pipe 5 and dissolved gas in the process of flowing down the packed bed 2. Is removed and stored in the treated water storage unit 3. The treated water is discharged from the treated water storage unit 3 by the transfer pump 8. A water level sensor 9 that constantly detects the water level is installed in the treated water storage unit 3, and a water level control valve 42 installed downstream of the transfer pump 8 is controlled by the control device 10 according to the output of the water level sensor 9, and treated. The water level of the water reservoir 3 is maintained at a predetermined water level.

  In addition to the water level sensor 9 and the control device 10, in order to maintain the water level of the treated water storage unit 3 in the vicinity of the deaeration tower body 1, peripheral devices such as various instruments that output detection signals of the water level sensor 9 Kind is installed.

  In this vacuum degassing apparatus, since the upper volume of the treated water reservoir 3 is reduced, if the water level of the treated water reservoir 3 is low and an effective suction head is not secured, treated water is removed from the treated water reservoir 3. When discharging with the transfer pump 8, there is a risk that cavitation due to vacuum negative pressure may occur at the suction port of the transfer pump. In addition to the above reasons, in practice, a safety margin for controlling the water level of the treated water is considered, and the water level of the treated water reservoir 3 is usually about 6 m or more.

  Such a conventional vacuum degassing apparatus is given a strength for holding a large amount of treated water in addition to the strength of the vacuum degassing apparatus itself, so that the weight is increased and the weight of the treated water is also added. Therefore, when installing this, it is necessary to reinforce the floor of the building and the structure (base, etc.), and there is a problem that the construction cost increases. Furthermore, in order to ensure the height of the vacuum degassing device, a part of the floor on the second floor may be penetrated, and there is a problem that the installation location of the vacuum degassing device is remarkably limited.

  For such problems, the treated water discharge port of the deaeration tower body and the suction port of the transfer pump are connected by a connecting pipe, the suction water surface during operation is set to be located in the connecting pipe, and the inside of the connecting pipe A vacuum deaeration device is known in which the height between the water surface and the shaft center of the transfer pump is larger than the effective suction lift of the pump (see Patent Document 1).

Japanese Patent No. 4119022

However, in recent years, as the demand for pure water quality becomes severe, the number and types of water treatment devices installed in the pure water production facility have increased, and the construction cost of the pure water production facility as a whole has increased. For this reason, in a pure water production facility equipped with a vacuum deaeration device or a vacuum deaeration device, it is required to further reduce the space and to reduce construction costs and facility costs.
Furthermore, since the deionized water production facility is installed in various regions, depending on the surrounding environment, there is a risk that peripheral devices may break down due to, for example, freezing. In particular, a countermeasure is required for a trouble that the automatic valve 41, the water level sensor 9, and the water level control valve 42 for controlling the water level of the treated water storage unit 3 break down.

  The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a vacuum deaeration device capable of reducing construction costs and equipment costs when installing the vacuum deaeration device.

  It is another object of the present invention to provide a space-saving vacuum degassing device that reduces the occupied volume of the vacuum degassing device and significantly increases the degree of freedom of installation location.

  It is another object of the present invention to provide a low-cost vacuum degassing device that omits the peripheral devices of the connecting pipe, enables safer operation, and facilitates operation management.

The vacuum deaeration device using the water head pressure of the present invention includes a gas-liquid contact material packed layer in an airtight interior, supplies water to be treated from above the packed layer, and is disposed below the packed layer. A degassing tower main body that discharges treated water from the treated water discharge port and discharges internal gas using vacuum means, a connecting pipe that discharges the treated water from the treated water discharge port, and a packed bed The lower part of the connecting pipe has a water level below the height H that is equal to or higher than the height at which the vacuum in the deaeration tower main body is maintained with respect to atmospheric pressure from the bottom, and the water level is set above the lower end of the connecting pipe. A treated water tank.
In the vacuum degassing apparatus of the present invention, if the height H can be secured, the horizontal positional relationship between the deaeration tower body and the treatment water tank is not required, and peripheral devices for the connecting pipe are also required regardless of the piping path of the connecting pipe. Therefore, it is possible to reduce the installation volume and increase the degree of freedom of the installation location and installation form.

  In this invention, it is preferable that the said connection pipe is comprised so that the said treated water may flow down naturally continuously. In this case, peripheral devices for the connecting pipe are unnecessary, and safer operation is possible and operation management can be facilitated.

  Moreover, in this invention, it is preferable that the treated water storage part is not provided substantially in the said deaeration tower main body lower part. In this case, since the weight of the vacuum deaerator can be further reduced, the construction cost can be reduced.

  Furthermore, in this invention, it is preferable that the said deaeration tower main body and the said treated water tank are installed in the upper floor and lower floor of a building. In this case, the installation location of the vacuum deaerator can be made more free.

As described above, according to the vacuum degassing apparatus of the present invention, the installation volume can be reduced and the degree of freedom of the installation location can be increased. Therefore, the vacuum degassing apparatus can be easily applied to a large-scale pure water production facility.
The vacuum degassing apparatus of the present invention does not require a large-scale construction for reinforcing the floor even when applied to a large-scale pure water production facility, and can reduce the peripheral equipment of the connecting pipe, thereby reducing the cost. be able to.

According to the vacuum degassing apparatus of the present invention, it is possible to reduce the installation volume of the vacuum degassing apparatus and increase the degree of freedom of the installation location.
Furthermore, according to the vacuum degassing apparatus of the present invention, the construction cost can be reduced by reducing the weight of the degassing tower body.
Furthermore, according to the vacuum degassing apparatus of the present invention, since the treated water reservoir is not substantially provided, peripheral devices for controlling the water level can be reduced.

It is a figure showing roughly the vacuum deaeration device of the embodiment by the present invention. It is a block diagram showing roughly pure water manufacturing equipment of an embodiment by the present invention. It is the schematic which shows an example of the pure water manufacturing equipment of embodiment. It is the schematic which shows an example of the pure water manufacturing equipment of an Example. It is the schematic which shows an example of the pure water manufacturing equipment of an Example. It is a figure which shows schematically the structure of the conventional vacuum deaeration apparatus. It is the schematic which shows an example of the pure water manufacturing equipment of a comparative example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments. In addition, in each figure, the same code | symbol is attached | subjected to the part which has the same function, and description is abbreviate | omitted.

(First embodiment)
FIG. 1 is a diagram schematically showing a configuration of a first embodiment according to the present invention.
In the degassing tower body 12 of the vacuum degassing apparatus 11 shown in FIG. 1, a packed bed 13 filled with a large number of gas-liquid contact materials having a large porosity is disposed. The lower part of the packed bed 13 is the volume of the end plate constituting the bottom of the deaeration tower body 12, and the treated water drain port 14 is opened at the center of the end plate. Thus, the treated water reservoir as provided in the conventional vacuum degassing apparatus is not substantially provided below the packed bed 13.

  Reference numeral 15 denotes a water supply pipe, and the water to be treated is supplied from the water supply pipe 15 and is poured into the packed bed 13 from a shower head (not shown) installed on the packed bed 13. In order to further reduce the dissolved gas concentration in the treated water, a plurality of sets of the shower head and the packed bed may be provided.

  Reference numeral 16 is a deaeration pipe for evacuation, and the vacuum pump 17 sucks and degass the gas in the deaeration tower body 12. The inside of the deaeration tower body 12 is evacuated by a vacuum pump 17 to a pressure higher than the pressure at which the water to be treated does not boil, for example, about 3.1 to 26.7 kPa (23 to 200 Torr).

The deaeration tower main body 12 is installed and fixed on a floor 18 of a building, and a treated water tank 20 is installed on a floor 19 below the floor 18. A connecting pipe 22 connected to the treated water drain port 14 of the deaeration tower body 12 is inserted into the treated water tank 20 through the water inlet 21 of the treated water tank 20.
At this time, the deaeration tower body 12 and the treated water tank 20 can be respectively installed on the upper floor and the lower floor of the same building or an adjacent building. Moreover, the deaeration tower main body 12 can also be installed on a structure such as a base installed outside the building.

  A pump 23 for sending treated water downstream is disposed at the outlet of the treated water tank 20.

  The height H from the water surface of the treated water tank 20 to the lower part of the packed bed 13 is set to be higher than the height at which the vacuum in the deaeration tower body 12 is maintained with respect to the atmospheric pressure applied to the water surface of the treated water tank 20. The upper limit of the height H is not limited as long as the deaeration tower body 12 can be installed. With this configuration, the water level in the connecting pipe 22 is maintained at a predetermined height h corresponding to the degree of vacuum in the deaeration tower body 12.

  The inner diameter of the connection pipe 22 can be appropriately designed according to the degree of vacuum and the height H in the deaeration tower body 12 so that the water level of the treated water is maintained in the connection pipe 22. The inner diameter of the connecting pipe 22 is set so that the linear flux of the treated water in the connecting pipe 22 is preferably 10 m / s or less, more preferably 5 m / s or less. In this way, it is preferable that the treated water continuously flows down in the connecting pipe 22. Therefore, the degree of vacuum in the deaeration tower body 12 can be stably maintained, and the water level of the treated water can be maintained within a predetermined upper and lower range in the connection pipe 22. Further, if a check valve or the like is provided above the water level in the connecting pipe 22, the treated water in the treated water tank 20 can be treated even if there is a problem that the water level is lower than the lower end 22 a of the connecting pipe 22. In addition, the backflow of an inert gas or the like that seals the treatment water tank can be prevented, and the vacuum degassing apparatus can be operated safely.

  A level sensor 24 is attached to the wall surface of the treated water tank 20. Then, a control device (not shown) controls the discharge amount of the pump 23 or on / off so that the water level of the treated water tank 20 detected by the level sensor 24 maintains a predetermined constant height above the lower end 22a of the connecting pipe 22. Is to control.

Further, the upper portion of the treated water tank 20 is sealed with an inert gas such as nitrogen gas in order to suppress the contamination of the treated water. Therefore, for example, an inert gas cylinder 26 may be installed in the vicinity of the treatment water tank 20 and the inert gas may be supplied to the treatment water tank 20 via the gas supply pipe 27.
At this time, the pressure of the inert gas in the treated water tank 20 may be a positive pressure so that the height H fluctuates and becomes large, and the water level of the treated water tank 20 does not become lower than the lower end 22a of the connecting pipe 22. More preferably, it is 0.1-1.0 kPa.

  The capacity | capacitance of the treated water tank 20 is not specifically limited, The capacity | capacitance comparable as the conventional treated water storage part may be sufficient.

  Since the deaeration tower main body 12 of this embodiment is installed above the treatment water tank 20 at the above-described height H, the pump 23 depends on the treatment flow rate regardless of the degree of vacuum of the deaeration tower main body 12. The head and discharge amount can be selected and used. Furthermore, there is no risk of cavitation on the suction side of the pump 23.

In this embodiment, since the weight of the vacuum degassing device increases as the flow rate of the water to be treated increases, for example, a more remarkable effect is obtained when the treatment flow rate is 50 m ³ / h or more. Furthermore, since the occupied volume can be significantly reduced in this embodiment, the vacuum deaeration device can be installed at an appropriate position with respect to other water treatment devices provided in the pure water production facility.

  In this embodiment, to-be-processed water is not specifically limited, City water, well water, industrial water, etc. can be deaerated. In addition, the treated water of each water treatment apparatus incorporated in the water treatment facility or the pure water production facility can be deaerated.

  Thus, in this embodiment, as long as the height H can be ensured, there is no need for a special device for monitoring or controlling the water level in the connecting pipe 22. Therefore, the connecting pipe 22 does not need to be a straight pipe and may be any route. Furthermore, since it does not ask | require horizontal positional relationship with the water treatment apparatus arrange | positioned forward and backward, the freedom degree, such as an installation place of a vacuum deaeration apparatus and a piping path | route, increases significantly. Furthermore, since the vacuum deaeration apparatus of this embodiment does not have a treated water storage part in the deaeration tower body 12, the base for installing the deaeration tower body 12 while reducing the weight of the vacuum deaeration apparatus itself. Since construction of foundations and reinforcement work for buildings can be reduced, construction costs for this can be reduced.

(Second Embodiment)
Next, an embodiment of a pure water production facility provided with the vacuum degassing apparatus of the first embodiment will be described below.

FIG. 2 is a block diagram showing a second embodiment according to the present invention.
A pure water production facility 30 shown in FIG. 2 is arranged at the rear stage of the pretreatment facility 31 and the pretreatment facility 31, and the tank T1 for storing the pretreatment water, the primary pure water facility 32 at the rear stage of the tank T1, and the primary pure water. Are stored in the tank T3 and the secondary pure water equipment 33 downstream of the tank T3.

  The primary deionized water equipment includes activated carbon device (AC) 321, cation exchange device (SC) 322, degassing device (DG) 323, anion exchange device (SA) 324, tank T2, pump P, reverse osmosis membrane device ( RO) 325, an ultraviolet oxidizer (TOC-UV) 326, a mixed bed ion exchanger (MB) 327, and a membrane degasser (MDG) 328 are provided in this order. The secondary pure water equipment 33 includes a heat exchanger (HEX) 331, an ultraviolet oxidizer (TOC-UV) 332, a polisher 333, a membrane deaerator (MDG) 334, a limiter, via a pump P at the rear stage of the tank T3. An outer filtration membrane device (UF) 335 is provided in this order.

In this pure water production facility, pure water is supplied to the use point (POU) at about 50 to 500 m ³ / h. For example, instead of the membrane deaerator 328, the vacuum deaerator of the first embodiment is used. Can be used. According to the first embodiment, as long as the height H can be ensured as described above, the installation position and the piping path are not limited, and it is not necessary to install peripheral devices on the connecting pipe. Therefore, it can be easily applied to a pure water production facility. Furthermore, the size of the deaeration tower body 12 can be easily changed according to the processing flow rate.

  Moreover, in this case, the water to be treated is treated by the water treatment facility in the previous stage, the dissolved carbonic acid concentration is 1 mg / L or less, and the specific resistance is 18.0 MΩ · cm or more. By depressurizing the inside of the deaeration tower body 12 to 3.1 to 20.0 kPa (23 to 150 Torr) and supplying the water to be treated, the dissolved oxygen concentration in the treated water can be 1 μg / L or less. . If a gas supply pipe is installed in the lower part of the degassing tower main body 12 and an inert gas such as nitrogen gas is injected into the degassing tower main body in a small amount, the oxygen removal efficiency can be improved, for example, the dissolved oxygen concentration in the treated water Can be 0.5 μg / L or less.

FIG. 3 is a schematic view when the vacuum degassing apparatus according to the first embodiment is installed as the degassing apparatus 323. In the deionized water production facility as shown in FIG. 2, a normal pressure or pressurized decarbonation tower that deaerates by air aeration is installed outdoors as the deaerator 323.
On the other hand, according to the vacuum deaeration apparatus of 1st Embodiment, the deaeration tower main body 12 and the connecting pipe 22 which comprise a vacuum deaeration apparatus in a building are set according to the installation place of another water treatment apparatus. It can be installed in a suitable position, and even if a vacuum degassing device is provided instead of the conventional decarboxylation tower, there is no need to reinforce the building.

  In the pure water production facility 30, when the vacuum degassing apparatus of the first embodiment is used as the degassing apparatus 323, an H-type strongly acidic ion exchange resin is used as the resin charged in the cation exchange apparatus in the previous stage. The feed water that has been treated with this cation exchange device and has become acidic with a liquidity of about pH 4 to 5 is poured into the deaeration tower body 12. At the same time, the inside of the deaeration tower body 12 is depressurized to 3.1 to 20.0 kPa (23 to 150 Torr) by the vacuum pump 17. Moreover, you may reduce dissolved carbonic acid density | concentration by inject | pouring inert gas, such as 0.5-5% of nitrogen gas with respect to the flow volume of supply water. Thus, the dissolved carbonic acid concentration can be made 10 mg / L or less by using the vacuum deaerator of this embodiment.

  Thus, the primary pure water manufactured by the primary pure water facility can be used as it is as medical water, pharmaceutical manufacturing water, cooling water for semiconductor manufacturing equipment, and the like. If the primary pure water is further processed by the secondary pure water facility 33 to obtain high-purity pure water having a specific resistance of 18.2 MΩ · cm or more and a dissolved oxygen concentration of 1 μg / L or less, it can be used as wafer cleaning water in the semiconductor manufacturing process. It can be preferably used.

  As described above, when the pure water production facility is configured using the vacuum degassing apparatus according to the first embodiment, the peripheral equipment required for the conventional vacuum degassing apparatus is reduced while reducing the installation volume and the construction cost. Since no kind is required, the degree of freedom of installation and design can be increased and the cost can be reduced.

  The vacuum degassing apparatus of the present invention is not limited to the above-described embodiment, and can be applied to various types of pure water production equipment and water treatment equipment as long as the effects of the present invention are not impaired.

Next, examples of the present invention will be described.
Example 1
In the pure water production facility of FIG. 2, the mixed bed type ion exchange device 327 to the heat exchanger 331 are installed in the same building 100 using the vacuum deaeration device 328a of the first embodiment. FIG. 4 shows a schematic configuration diagram of a part of the pure water production facility according to the first embodiment.
The building is a two-story building with a first basement floor, the deaeration tower body 12 of the vacuum deaeration device 328a of the first embodiment is installed on the second floor part (reference numeral 18), and the underground tank T3 is treated as a treated water tank. 20 is used.
In the vacuum degassing apparatus 328a, the height of the degassing tower body 12 is 4.5 m, the capacity of the tank T3 is 200 meters ^3.

  In Example 1, since the deaeration tower main body 12 can be installed in a building, in this case, the volume is approximately 30 to 50% compared with the case where a conventional vacuum deaeration device is used before and after the vacuum deaeration device. Can be reduced. Further, there is no need to install peripheral devices in the connecting pipe 22.

(Example 2)
In the first embodiment, the vacuum deaerator 328 a is installed on the roof 101 of the building 100. FIG. 5 shows a schematic configuration diagram of a part of the pure water production facility according to the second embodiment.
As in Example 2, the vacuum degassing apparatus according to the embodiment can not only reduce the weight as compared with the conventional vacuum degassing apparatus, but also does not need to install peripheral devices in the connecting pipe 22, and thus the degassing tower. The main body 12 can be installed on the roof of a building.

(Comparative Example 1)
In Example 1, a conventional vacuum deaerator 328b having a total height of 10.5 m as shown in FIG. 6 is installed outside the building. A schematic configuration diagram of a part of the pure water production facility of Comparative Example 1 is shown in FIG.
In Comparative Example 1, since the deaeration tower main body 1 is installed on the base placed outside the building, the base must be reinforced. Further, the outlet of the preceding water treatment apparatus installed in the building and the water supply pipe 5 of the deaeration tower body 1 are connected by piping, and the water in the latter stage in which the treated water reservoir 3 is installed in the building. It connects to the water inlet of a processing apparatus by piping via the treated water transfer pump 8. FIG. Therefore, depending on the position in the building of the water treatment device arranged immediately before and after the vacuum degassing device, the piping path becomes complicated. Moreover, since it arrange | positions outdoors, the countermeasure against the failure of peripheral equipment for the water level control of the deaeration tower main body 1 is desired depending on an environment.

DESCRIPTION OF SYMBOLS 11 ... Vacuum deaeration apparatus, 12 ... Deaeration tower main body, 13 ... Packing bed, 14 ... Treated water drain, 15 ... Supply pipe, 16 ... Deaeration pipe, 17 ... Vacuum pump, 18 ... Floor, 19 ... Floor, 20 A treatment water tank, 21 a water inlet, 22 a connecting pipe, 23 a pump, 24 a level sensor, 25 a gas supply pipe, 26 an inert gas cylinder.

Claims (4)

A gas-liquid contact material filling layer is provided in an airtight interior, water to be treated is supplied from above the filling layer, treated water is discharged from a treated water discharge port below the filling layer, and vacuum means A degassing tower main body adapted to discharge the internal gas,
A connecting pipe for discharging the treated water from the treated water discharge port;
The lower part of the packed bed has a water level below the height H that is equal to or higher than the height at which the vacuum in the deaeration tower body is maintained with respect to atmospheric pressure, and is constant above the lower end of the connecting pipe. A treated water tank in which the water level is set;
A vacuum deaerator using water head pressure characterized by comprising:   The vacuum degassing apparatus according to claim 1, wherein the connection pipe is configured such that the treated water continuously flows down naturally.   The vacuum degassing apparatus according to claim 1 or 2, wherein a treated water reservoir is substantially not provided at a lower portion of the degassing tower main body.   The vacuum degassing apparatus according to any one of claims 1 to 3, wherein the deaeration tower body and the treatment water tank are installed on an upper floor and a lower floor of a building.

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