Claims
- 1. A method of absorbing and removing suspended impurities present in trace amounts in condensate water resulting from steam powder generating facilities and which consist substantially of metal oxides, which method comprises:
- (A) mixing a cation exchange resin (H form) with an anion exchange resin (OH form) at a volume ratio in the range of 0.5-2.0 of the cation exchange resin and the anion exchange resin, respectively, to form a mixed bed ion exchange resin layer,
- said cation exchange resin;
- (a) having a dual structure with a skin layer being present to a depth of at least 0.1-10 .mu.m from the surface;
- (b) comprising particles in a true spherical form having a diameter of 0.2-1.2 mm and an effective specific surface area of 0.02-0.20 m.sup.2 per gram of dry resin, with the effective specific surface area being measured on the basis of the amount of absorption of krypton,
- (c) having such a surface layer structure that unit granules having a size of 0.1-1.0 .mu.m are seen to bind with one another when examined under a scanning electron microscope in a field of view ranging from a magnification of 50 to 200,000,
- (d) having a honeycomb and/or scaly surface structure with grooves in the surface, unit honeycombs and/or scales each having a unit surface area of 1-50 .mu.m.sup.2 and agglomerated together to form an irregular surface structure and morphology, with the surface being such that the individual unit honeycombs and/or scales are adjacent to one another via grooves having a width of 0.1-5.0 .mu.m, said grooves having an overall length of 100-1,000 mm per mm.sup.2 ;
- (e) having a crosslinking degree of from 3% to 8%;
- (f) having a surface pH (the concentration of hydrogen ions at the solid surface) of 1.50-1.90 in a wet state; and
- (g) having an interfacial electrokinetic potential (zeta potential) of -20 to -40 mV in a powder state in the range of about 50-100 .mu.m (about 150-300 mesh) obtained by pulverizing said resin;
- said anion exchange resin;
- (a') comprising particles in a true spherical form having a diameter 0.2-1.2 mm and an effective specific surface area of 0.02-0.10 m.sup.2 per gram of dry resin, with the effective specific surface area being measured on the basis of the absorption of krypton;
- (b') having a crosslinking degree of from 3% to 8%;
- (c') having a surface pH (the concentration of hydrogen ions at the solid surface) of 11.50-13.80 in a wet state; and
- (d') having an electrokinetic potential (zeta potential) of +20 to +45 mV in a powder state in the range of about 50-100 .mu.m (about 150-300 mesh) obtained by pulverizing said resin; and
- (B) causing the condensate water to pass through said mixed bed ion exchange resin layer at a linear velocity of 60-130 m/h, to attain contact between said condensate water and said resin layer.
- 2. A method according to claim 1 wherein said linear velocity is 80-120 m/h.
- 3. A method according to claim 1 wherein said linear velocity is 100-115 m/h.
- 4. A method of absorbing and removing suspended impurities present in trace amounts in condensate water resulting from steam powder generating facilities and which consist substantially of metal oxides, which comprises:
- (A) finely pulverizing a cation exchange resin (H form) and an anion exchange resin (OH form), each present in true spherical form having a diameter of 0.2-1.2 mm, to obtain a powdered cation exchange resin of a size in the range of about 60-400 mesh and a powdered anion exchange resin of a size range in the range of about 60-400 mesh;
- (B) mixing the powdered cation exchange resin with the powdered anion exchange resin at a weight ratio in the range of 0.5-6.0, on a dry basis;
- (C) suspending and dispersing the mixture in water to form a slurry in solution;
- (D) precoating filter septa with the water-resin slurry in solution to form a precoat that serves as a filtrating/demineralizing layer, with the amount of precoating being 0.5-2.0 kg (dry basis) of mixed resin per m.sup.2 of filter area; and
- (E) causing the condensate water to pass through the precoated filtrating/demineralizing layer at a linear velocity of 1.0-13.0 m/h, to attain contact between said condensate water and said precoat;
- said cation exchange resin
- (a) having a dual structure with a skin layer being present to a depth of at least 0.1-10 .mu.m from the surface;
- (b) comprising particles in a true spherical form having a diameter of 0.2-1.2 mm and an effective specific surface area of 0.02-0.20 m.sup.2 per gram of dry resin, with the effective specific surface area being measured on the basis of the amount of absorption of krypton;
- (c) having such a surface layer structure that unit granules having a size of 0.1-1.0 .mu.m are seen to bind with one another when examined under a scanning electron microscope in a field of view ranging from a magnification of 50 to 200,00;
- (d) having a honeycomb and/or scaly surface structure with grooves in the surface, unit honeycombs and/or scales each having a unit surface area of 1-50 .mu.m.sup.2 and agglomerated together to form an irregular surface structure and morphology, with the surface being such that the individual unit honeycombs and/or scales are adjacent to one another via grooves having a width of 0.1-5.0 .mu.m, said grooves having an overall length of 100-1,000 mm per mm.sup.2 ;
- (e) having a crosslinking degree of from 3% to 8%;
- (f) having a surface pH (the concentration of hydrogen ions at the solid surface) of 1.50-1.90 in a wet state; and
- (g) having an interfacial electrokinetic potential (zeta potential) of -20 to -40 mV in a powder state in the range of about 50-100 .mu.m (about 150-300 mesh) obtained by pulverizing said resin; and wherein
- said anion exchange resin
- (a') comprises particles in a true spherical form having a diameter of 0.2-1.2 mm and an effective specific surface area of 0.02-0.10 m.sup.2 per gram of dry resin, with the effective specific surface area being measured on the basis of the absorption of krypton;
- (b') have a crosslinking degree of from 3% to 8%;
- (c') have a surface pH (the concentration of hydrogen ions at the solid surface) of 11.50-13.80 in a wet state; and
- (d') have an electrokinetic potential (zeta potential) of +20 to +45 mV in a powder state in the range of about 50-100 .mu.m (about 150-300 mesh) obtained by pulverizing said resin.
- 5. A method according to claim 4 wherein the weight ratio of powdered cation exchange resin to said powdered anion exchange resin is in the range of 2.0-3.0.
- 6. A method according to claim 4 wherein said linear velocity is 5-8 m/h.
Priority Claims (1)
Number |
Date |
Country |
Kind |
1-271466 |
Oct 1989 |
JPX |
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Parent Case Info
This application is a continuation of application Ser. No. 07/899,616, filed May 28, 1992, which in turn is a continuation-in-part of application Ser. No. 07/866,080, filed Apr. 3, 1992, which is a continuation of Ser. No. 07/759,002, filed Sep. 11, 1991, all now abandoned, which in turn is a divisional of U.S. application Ser. No. 07/600,809, filed Oct. 22, 1990, now abandoned.
US Referenced Citations (4)
Foreign Referenced Citations (2)
Number |
Date |
Country |
59-18705 |
Jan 1984 |
JPX |
59-98117 |
Jun 1984 |
JPX |
Non-Patent Literature Citations (1)
Entry |
Izumi et al., "Crud Removal Characteristics of Newly Developed Ion Exchange Resins (Second Report)", 52nd Annual Mtg of Int'l. Water Conf. Pittsburgh, Pa. Oct. 21-23, 1991. |
Divisions (1)
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Number |
Date |
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Parent |
600809 |
Oct 1990 |
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Continuations (2)
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Number |
Date |
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Parent |
889616 |
May 1992 |
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Parent |
759002 |
Sep 1991 |
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Continuation in Parts (1)
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Number |
Date |
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Parent |
866080 |
Apr 1992 |
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