- Patent Number:
5,670,094
- Appl. No:
08/590,361
- Application Filed:
January 25, 1996
- نبذة مختصرة :
In an ozonized water producing apparatus in which a pressurized ozone gas generated by an electric discharge type ozonizer is dissolved in water to be treated through a porous hollow-fiber membrane, an infinite variable-speed control type pump is provided upstream of the hollow-fiber membrane to maintain the water pressure inside the hollow fibers higher than the ozone gas pressure and to control the water pressure and flow rate, and a control mechanism is provided to control the ozone concentration in the treated water on the basis of the ozone gas concentration. Thereby treated water containing neither tiny bubbles nor impurities is obtained, and the concentration, flow rate and pressure of the treated water are controlled at constant levels.
- Inventors:
Sasaki, Kenichi (Kanagawa-ken, JPX); Saito, Takayuki (Kanagawa-ken, JPX); Nakajima, Ken (Kanagawa-ken, JPX); Imai, Mitsuru (Kanagawa-ken, JPX)
- Assignees:
Ebara Corporation (Tokyo, JPX)
- Claim:
What is claimed is
- Claim:
1. An ozonized water producing method in which a pressurized ozone gas generated by an electric discharge type ozonizer is dissolved in water to be treated through a hollow-fiber membrane, characterized in that a water pressure inside the hollow-fiber membrane is maintained higher than the pressure of the ozone gas supplied to the outside of the hollow-fiber membrane to prevent tiny bubbles and impurities from getting mixed in the water being treated, and an ozone concentration in treated water is controlled on the basis of the concentration of the ozone gas.
- Claim:
2. An ozonized water producing method according to claim 1, wherein said water pressure is higher than the ozone gas pressure by 0.1 kg.multidot.f/cm.sup.2 or more.
- Claim:
3. An ozonized water producing method according to claim 1, wherein said water pressure inside the hollow-fiber membrane is controlled by controlling a rotational speed of an infinite variable-speed control type pump provided for supplying a water to said hollow-fiber membrane.
- Claim:
4. An ozonized water producing method according to claim 3, wherein the rotational speed of said infinite variable-speed control type pump is controlled based on flow rate and pressure of a water supplied to said hollow-fiber membrane by said pump.
- Claim:
5. An ozonized water producing method according to claim 4, wherein said rotational speed of said pump is so controlled that flow rate and pressure of a water at an outlet of said apparatus is maintained at a constant level.
- Claim:
6. An ozonized water producing method according to claim 1, wherein said ozone gas concentration is controlled by varying a discharge voltage of said electric discharge type ozonizer.
- Claim:
7. An ozonized water producing method according to any one of claims 1 to 6, wherein, when no ozonized water is produced, a gas piping which extends from an inlet of said ozonizer to an outlet of said hollow-fiber membrane is purged with a dry gas.
- Claim:
8. An ozonized water producing method according to claim 7, wherein said dry gas is an oxygen gas and/or nitrogen gas which is (are) supplied to said ozonizer when ozonized water is produced.
- Claim:
9. An ozonized water producing apparatus in which a pressurized ozone gas generated by an electric discharge type ozonizer is dissolved in water to be treated through a hollow-fiber membrane, characterized by comprising: an infinite variable-speed control type pump which is provided upstream of said hollow-fiber membrane to maintain a water pressure inside hollow fibers higher than a pressure of said ozone gas supplied to outside of said hollow-fiber membrane and to control the water pressure and flow rate; and a control mechanism for controlling an ozone concentration in treated water on the basis of the concentration of the ozone gas.
- Claim:
10. An ozonized water producing apparatus according to claim 9, wherein a flowmeter and a pressure gauge are provided upstream of said hollow-fiber membrane, and said apparatus includes a control mechanism for processing signal values output from said flowmeter and pressure gauge in an arithmetic circuit to control said infinite variable-speed control type pump.
- Claim:
11. An ozonized water producing apparatus according to claim 9, wherein said ozone concentration control mechanism includes: an ozonized water concentration meter provided downstream of the hollow-fiber membrane; an arithmetic circuit for processing a value measured by said concentration meter; and a voltage varying device for varying a discharge voltage of said electric discharge type ozonizer on the basis of the processed value.
- Claim:
12. An ozonized water producing apparatus according to any one of claims 9 to 11, wherein said hollow-fiber membrane is a polytetrafluoroethylene porous hydrophobic membrane which is permeable to gases, e.g. oxygen, nitrogen, etc., but impermeable to water, said membrane having a pore diameter distribution centered in a range of from 0.01 .mu.m to 1 .mu.m.
- Claim:
13. An ozonized water producing apparatus according to any one of claims 9 to 11, further comprising means for purging a gas piping which extends from an inlet of said ozonizer to an outlet of said hollow-fiber membrane with a dry gas when no ozonized water is produced.
- Current U.S. Class:
261/27; 2611/221; 261DIG42
- Current International Class:
B01F 304
- Patent References Cited:
2812861 November 1957 Bickford
4355636 October 1982 Oetjen et al.
4555335 November 1985 Burris
4836929 June 1989 Baumann et al.
4897359 January 1990 Oakley et al.
4992216 February 1991 Saita et al.
5037610 August 1991 Fukasawa et al.
5073268 December 1991 Saito et al.
- Primary Examiner:
Miles, Tim R.
- Attorney, Agent or Firm:
Armstrong, Westerman, Hattori, McLeland & Naughton
- الرقم المعرف:
edspgr.05670094
Processing Request
No Comments.