JP3240932B2 - Ultrapure water transmission equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the Ri ultrapure water water set Bei engagement <br/>, in particular, a branch pipe for supplying the ultrapure water used location through the main water feed pipe from the ultrapure water production system It relates Bei ultrapure water water set with a sterilizing apparatus for sterilizing.

[0002]

2. Description of the Related Art As shown in FIG. 2, ultrapure water conventionally used as semiconductor cleaning water, etc.
Raw water (industrial water, city water, well water, etc.) using an ultrapure water production system composed of the primary pure water production system 2 and the subsystem 3
The ultrapure water produced by processing
Branch pipe 5 branched from feed pipe 4A of main water feed pipe 4
(5A, 5B ... 5N) and each use place 6 (6A, 6B
.. 6N). Excess ultrapure water is returned to the subsystem 3 from the return pipe 4B of the main water supply pipe 4, and is reused after processing.

In such an ultrapure water supply system, it is necessary to periodically sterilize the main water supply pipe and the branch pipe.
In particular, since the branch pipe has a problem of reverse contamination from a valve at a place of use, it is important to periodically sterilize and maintain an aseptic state.

Conventionally, H ₂ O ₂ sterilization, medium-temperature H ₂ O ₂ sterilization, or heat sterilization has been performed for sterilization of a water supply system of an ultrapure water supply system. Although not generalized, an ozone sterilization method is also known.

[0005]

Conventional sterilization methods [SUMMARY OF THE INVENTION] are both, including subsystems ultrapure water water equipment, mainly H ₂ O ₂ water main water supply pipe, 40 ° C. of about H ₂ O ₂ Water The operation is performed by circulating hot water or ozone water of about 50 to 300 ppb. Therefore, it is necessary to stop the operation of the ultrapure water supply equipment.

[0006] Each sterilization method has the following problems. H ₂ O ₂ sterilization or medium temperature H ₂ O ₂ sterilization needs to be performed using 1 to 5% H ₂ O ₂ water for several hours, and the sterilization time is long. Heat sterilization is 80-9
In order to pass hot water of 0 ° C., it is necessary to use heat-resistant pipes and members, and the material is restricted, which increases the cost.
Ozone sterilization can be sterilized with ozone water of a relatively low concentration in a short period of time, but it is necessary to provide an ozone generating facility, and the cost increases if the amount of ozone water used for sterilization is large. In addition, if the pipe to be sterilized is long, the natural decomposition of ozone will occur on the way, and ozone water having a concentration twice or more than the usual concentration will be required for reliable sterilization. In addition, it is necessary to use an ozone-resistant PVDF (polyvinylidene fluoride) pipe, and the material is restricted.

[0007] The present invention solves the above-mentioned conventional problems, and branches the supply of ultrapure water from the ultrapure water production apparatus to the place of use via the main water supply pipe without stopping the operation of the ultrapure water supply equipment. ultrapure water water equipment which can be sterilized piping efficiently
The purpose is to provide.

[0008]

An ultrapure water supply system according to the present invention comprises a feed pipe 4A and a return pipe 4B from an ultrapure water producing apparatus.
An ultrapure water supply system for supplying ultrapure water to a place of use via a main water supply pipe 4 and a branch pipe 5, wherein the branch pipe 5 is provided with ultrapure water branched from the feed pipe 4A. A feed pipe 5a that flows in, a water supply pipe 5b that supplies ultrapure water that has flowed into the feed pipe 5a to a place of use, and a return pipe 5c that returns excess ultrapure water from the feed pipe 5a to the return pipe 4B. A valve V is provided for each of the feed pipe 5a, the water supply pipe 5b, and the return pipe 5c.
_1, V _2, V ₃ are provided, and the downstream side of the valve V ₁ of the said transmission Ri pipe 5a, the return pipe 5c outflow and inflow capable port of each water on the upstream side of the valve V ₃ of 7
a and 7c are provided, and the ports 7a and 7c are respectively provided.
The water disinfection device 10 having a water outlet 22a and a water inlet 21a that can be connected to the c is provided .

In the present invention, the inlet and outlet of the sterilizer are connected to the ports provided in the branch pipe, and only the water supply from the main water supply pipe to the branch pipe is stopped. By circulating the sterilizing water in the above, the branch pipe can be easily sterilized without stopping the operation of the ultrapure water supply equipment. Since the sterilizer is movable, it is possible to sterilize each branch pipe sequentially to sterilize all the branch pipes.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings.

[0011] Figure 1 is an ultra-pure water water equipment of the present invention, FIG. 2
The branch pipe 5 (5A-
It is a system diagram which shows the example applied to the sterilization of 5N).

The ultrapure water sent from the ultrapure water production apparatus consisting of the pretreatment system, the primary pure water system, and the sub-system via the feed pipe 4A of the main water feed pipe 4 is supplied to the feed pipe 5a of the branch pipe 5 and the place of use. From the water supply pipe 5b to the place of use 6
Supplied to Excess ultrapure water is circulated from the return pipe 5c to the subsystem of the ultrapure water production device via the return pipe 4B of the main water supply pipe 4. V ₁ , V ₂ , and V ₃ are valves provided at each part of the branch pipe 5.

[0013] branch pipe 5 of the feed pipe 5a of the valve V ₁ of the downstream and the return pipe 5c of the respective inflow and outflow of water on the upstream side of the valve V ₃ is available ports 7a, 7c are provided. The ports 7a and 7c are normally closed, and are opened when a receiving port 21a and a sending port 22a of the mobile sterilizer 10 described later are connected.

The mobile sterilizer 10 includes a UV irradiator 1
1, a tank 12, an ozone generator 13 for injecting ozone into the tank 12, a pump 14, an ozone meter 15 for measuring ozone concentration, and a filter 16. Tank 1
No. 2 is configured so that the undissolved ozone gas sent out by introducing nitrogen is decomposed by the activated carbon filter 17 and discharged out of the system. Also, this mobile sterilizer 1
0, receiving pipe 21 of the water with the valve _{V 4} and the valve V
₅ is provided with a water delivery pipe 22 provided with
One receiving port 21a is detachably connected to the port 7c of the return pipe 5c, and the sending port 22a of the sending pipe 22 is detachably connected to the port 7a of the sending pipe 5a. Drain pipe 23 provided with a valve V ₆ is branched to the delivery pipe 22.

The UV irradiator 11 is for decomposing and removing excess ozone, and preferably emits UV mainly having a wavelength of 254 nm. The UV irradiation device 1
1 is preferably turned off during sterilization and turned on when removing residual ozone after sterilization.

The structure of the tank 12 is not particularly limited.
In order to ensure ozone resistance, a material made of a SUS or PVDF coating material is preferable.

The ozone generator 13 is not particularly limited, but generally, an ozone generator that electrolyzes ultrapure water to generate ozone is preferable.

The ozone meter 15 preferably has a measurement lower limit of 5 ppb or less. The ozone concentration can be measured using an ORP meter instead of the ozone meter.

The filter 16 is preferably a filter having a pore size of 0.45 μm or less.

In order to sterilize the branch pipe 5 with the mobile sterilizer 10, the mobile sterilizer 10 must be connected to the branch pipe 5.
And the receiving port 21a of the receiving pipe 21 is connected to the port 7c of the return pipe 5c.
Are connected to the ports 7a of the feed pipes 5a, respectively, to obtain the state of FIG. 1, and sterilization is performed in the following procedure.

(I) The valves V ₁ and V _{4 are} opened, and the valves V ₅ and V
V ₆ Close the valve _V 2, _{V 3} in the closed state, the feed pipe 4
A, Ultrapure water is stored in the tank 12 through the port 7c of the return pipe 5c of the branch pipe 5 and the receiving pipe 21.

[0022] (ii) thereafter, closing the valve V _1, actuates the pump 14 by opening the valve V _5, by operating the ozone generator 13, to inject ozone sterilizer ozone water having a predetermined concentration 10 And a branch pipe 5 (a pipe between the port 7a and the port 7c). At this time, the UV irradiation device 11 is stopped. This ozone sterilization is preferably performed by circulating ozone water having an ozone concentration of 20 to 300 ppb at a flow rate of 0.05 to 1.0 m / sec for 30 to 120 minutes.

(Iii) After the end of the ozone sterilization, the ozone generator 13 is stopped, the UV irradiation device 11 is operated, and UV irradiation is performed while water circulation is continued to decompose and remove ozone in the system. Ozone gas phase in the tank 12 is extruded by blowing N _2, was removed through activated carbon filter 17, and discharges the process gas out of the system. This ozone removal
Usually, it is carried out for 15 to 30 minutes until the ozone concentration in the system becomes 5 ppb or less.

[0024] (iv) after the ozone removal, the pump 14 is stopped to close the valve V _5, by opening the valve V _1, V _6, the branch pipe ultrapure water from the main water supply pipe 4 of the feed pipe 4A The water in the system is discharged from the discharge pipe 23 through the port 7c of port 5 to the sterilizer 10, and washed. This draining and washing is preferably performed for 15 minutes or more, for example, for about 30 to 60 minutes.

[0025] (v) system in After cleaning, closing the valve _{V 4,}
While removing the mobile sterilizer 10 from the branch pipe 5,
The valves V ₃ and V ₂ are opened, and the use of the ultrapure water at the use location 6 is restarted.

In the case of a mobile sterilizer having such an ozone generating means and an ozone removing means and having a water inlet and a water outlet which can be attached to and detached from the branch pipe, the apparatus is provided on the branch pipe by the above procedure. After ozone water is circulated in the pipeline between the two ports, ozone is removed, and thereafter, the branch pipe can be easily sterilized by washing with water.

The number of ports provided in the branch pipe is not necessarily two, but may be three or more. In this case, a desired section of the branch pipe can be sterilized by selecting a port for connecting the mobile sterilizer. Generally, as shown in FIG.
One port 7a, 7c is provided for each of the feed pipe 5a on the upstream side of b and the return pipe 5c on the downstream side.
Sterilize the inside of the pipe between c.

In FIG. 1, a UV irradiation device is used as a means for removing ozone, but an activated carbon filter may be used for removing ozone. When an activated carbon filter is used, a fibrous activated carbon filter is installed in the line of the sterilizer, and when circulating ozone water, the activated carbon filter is bypassed, and a channel is passed so that water is passed through the activated carbon filter only when ozone is removed. Switch.

Ozone sterilization and UV irradiation will be described below with reference to experimental examples.
The effect of ozonolysis by irradiation is shown.

EXPERIMENTAL EXAMPLE 1 Ultrapure water from an ultrapure water production facility was received in a storage tank, and the ultrapure water in the storage tank (200 L capacity) was pumped out by a 20-A clean PVC pipe and then returned again to a length of 20 m. A circulation pipe was installed. In addition, a UV irradiation device (UV wavelength: 254 nm) and an ozone meter were attached in the middle of the pipe.

10 mL of Pseudomonas spp.
When added and circulated for 3 days, the number of viable bacteria in the system is 20-
It became 30 pieces / 100 mL.

Therefore, a Teflon balloon is put in this storage tank, and an ozone generator (Sakura Kikai Seisakusho Co., Ltd. “OM”) is used.
-2 type ") is diffused so that the measured value of the ozone meter becomes 50 to 100 ppb, and 0.5 m ³ /
Water was circulated at hr.

Table 1 shows the number of viable bacteria in the system with respect to the circulation time of the ozone water.

[0034]

[Table 1]

After the ozone water was circulated for 45 minutes, the diffusion of ozone was stopped, and the UV irradiator was operated to turn it on at 0.2 KW / m.
^{When the} UV irradiation device was operated at ³ and the system was circulated for another 30 minutes with UV irradiation at 0.2 KW / m ³ , the ozone concentration in the system became 5 ppb or less.

From these results, it can be seen that sterilization can be efficiently performed by injecting ozone, and after sterilization, ozone can be easily decomposed and removed by UV irradiation.

[0037]

As described above in detail, according ultrapure water water <br/> set Bei of the present invention, without stopping the operation of the ultrapure water water equipment, the main water feed pipe from the ultrapure water production system The branch pipe that supplies ultrapure water to the place of use via the tub can be efficiently sterilized.

The ultra-pure water water equipment of the present invention, the branch pipes only sterilization is most needed, because it is intended to sterilize separately, in a short period of time without stopping the operation of the ultrapure water water facilities Can be sterilized. In addition, even when ozone sterilization is performed, it is not necessary to use high-concentration ozone water to sterilize a relatively short branch pipe, so that there is no restriction on the material of the pipe.

[Brief description of the drawings]

1 is a system diagram showing an embodiment of the ultra-pure water water equipment of the present invention.

FIG. 2 is a system diagram showing an overall configuration of an ultrapure water supply system.

[Explanation of symbols]

 Reference Signs List 1 Pretreatment system 2 Primary pure water system 3 Subsystem 4 Main water supply pipe 4A Send pipe 4B Return pipe 5,5A, 5B, 5N Branch pipe 6,6A, 6B, 6N Use place 7a, 7c Port 10 Mobile sterilization Device 11 UV irradiation device 12 Tank 13 Ozone generator 15 Ozone meter

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ identification code FI C23G 3/04 C23G 3/04 (58) Investigated field (Int.Cl. ⁷ , DB name) C02F 1/50 C23G 3/04 B08B 9/00

Claims (1)

(57) [Claims] An ultrapure water supply system for supplying ultrapure water to a place of use from an ultrapure water production device via a main water supply pipe 4 including a feed pipe 4A and a return pipe 4B and a branch pipe 5, The branch pipe 5 includes a feed pipe 5a into which ultrapure water branches and flows in from the feed pipe 4A, a water supply pipe 5b for supplying ultrapure water flowing into the feed pipe 5a to a place of use, and a feed pipe 5a. and a return pipe 5c back to said return Ri pipe 4B excess ultrapure water from said transmission Ri pipe 5a, is provided with a valve _{V 1,} V 2, _{V 3} to each of the water supply pipe 5b and return pipe 5c, and a downstream side of the valve _{V 1} of the said transmission Ri pipe 5a, the return pipe 5c
The outflow of the respective water on the upstream side of the valve V ₃ and the inlet capable ports 7a, 7c are provided, each said port 7a, the connectable water 7c outlet 2
Ultrapure water supply equipment comprising a movable water sterilizer 10 having a 2a and a receiving port 21a.