The present invention relates to an exhaust oxygen recycling apparatus, and, more particularly, to an exhaust oxygen recycling apparatus for ozone treatment equipment, which is used to refine the exhaust oxygen discharged to the air after the reaction in the ozone treatment equipment used to disinfect, remove tastes, smells and colors, reduce organic compounds and perform oxidation of metals such as iron, manganese and the like and to recycle the refined oxygen to generate ozone. Further, the present invention relates to an ozone-using system including the exhaust oxygen recycling apparatus for ozone treatment equipment.
Ozone treatment equipment is used in many fields, such as water treatment, digestion tanks, bleaching, sterilization, disinfection, semiconductor equipment systems and the like, for the purpose of removing smells and colors, improving coagulation efficiency, reducing the production of organic chlorine compounds and improving cleanliness and the like.
Meanwhile, organic sludge, such as sewage sludge, excretion sludge or the like, increases every year. However, sludge treatment facilities for incineration or burying sludge are not installed due to local NIMBY phenomena or the like. Further, since discarding sludge into the sea is internationally prohibited, there is no method of suitably disposing of sludge.
Currently, as a method for reducing sludge, anaerobic sludge treatment is generally used. That is, in large-scale sewage disposal plants, sludge is reduced using an anaerobic digestion tank.
The primary sludge is introduced into an anaerobic digestion tank 170 through a movement line 135 via a concentration tank 130, and the secondary sludge is introduced into the anaerobic digestion tank 170 through a movement line 145 via a centrifugal concentrator 140 and is then mixed with the primary sludge.
The anaerobic digestion tank 170 is provided with a circulation line 160, one end of which is connected to the lower side of the anaerobic digestion tank 170 and the other end of which is connected to the upper side of the anaerobic digestion tank 170, and the mixed sludge in the anaerobic digestion tank 170 is circulated through the circulation line 160. A steam line 155 is connected to the upper side of the anaerobic digestion tank 170 such that high-temperature steam generated from a boiler 150 is supplied into the anaerobic digestion tank 170 through the steam line 155.
However, the apparatus for reducing sludge is problematic in that it cannot sufficiently reduce sludge because the mixed sludge including the primary and secondary sludge is digested in the anaerobic digestion tank 170 only by an anaerobic digestion process.
Therefore, conventionally, in order to increase the efficiency of reduction of sludge, various methods for easily decomposing sludge in an anaerobic tank by solubilizing organic matter included in the anaerobic tank, such as ultrasonic treatment, ozone treatment, heat treatment and the like, have been used.
As shown in
In a general ozone generator, when oxygen having a high purity of 90˜95% or more is supplied, ozone is produced in several steps. In this case, the amount of ozone that is produced is about 10% with respect to the amount of the supplied oxygen. Therefore, ozone discharged from the ozone generator includes oxygen having a purity of 80˜85% or more, so that ozone and oxygen are supplied together to the solubilization unit 220. Meanwhile, ozone supplied to the solubilization unit 220 solubilizes the sludge discharged from the anaerobic digestion tank 210, and is then discharged to the air via an ozone discharge unit. In this case, the exhaust gas discharged to the air includes oxygen (O2) having a purity of 80˜85% or more as well as CO2, CH4, H2S and the like. That is, conventionally, oxygen (O2) having a purity of 80˜85% or more is directly discharged to the air.
Meanwhile, even in the fields of water treatment, bleaching, sterilization, disinfection, semiconductor equipment systems and the like, after the sterilization by ozone, oxygen (O2) having a purity of 80˜85% or more is refined and then discharged to the air together with impurities (impurity gases).
However, the price of the oxygen (O2) having a purity of about 99.9%, which is commercially available from oxygen manufacturing companies, is about KRW170˜KRW200 (about US$0.17˜US$0.20) per 1 Kg, and, as shown in
As described above, conventionally, oxygen purchased or produced at high cost has been mostly discharged to the air, that is, resources have not been sufficiently recycled.
Accordingly, the present invention has been devised to solve the above-mentioned problems, and an object of the present invention is to provide an exhaust oxygen recycling apparatus for ozone treatment equipment, in which an exhaust oxygenic gas being discharged to the air after reaction in the ozone treatment equipment is refined, and then a refined exhaust gas is recycled to generate ozone.
Another object of the present invention is to provide an ozone-using system, in which ozone is generated using the oxygen provided by an exhaust oxygen recycling apparatus for ozone treatment equipment used in the fields of water treatment, digestion tanks, bleaching, sterilization, disinfection, semiconductor equipment systems and the like, and the generated oxygen is self-recycled.
In order to accomplish the above objects, an aspect of the present invention provides an exhaust oxygen recycling apparatus for ozone treatment equipment, which is used to refine an exhaust oxygenic gas, the exhaust oxygenic gas being discharged to the air after reaction in the ozone treatment equipment, and to recycle a refined oxygenic gas to generate ozone, comprising: an impurity removing unit for removing impurities from components included in an exhaust gas, the impurities being apt to be recognized as impurities in an ozone generator; and a compressor for compressing the exhaust gas and/or a refined gas to a pressure at which the exhaust gas and/or the refined gas can be supplied to the ozone generator, the refined gas being obtained by removing the impurities from the exhaust gas using the impurity removing unit
In the exhaust oxygen recycling apparatus, the impurity removing unit may remove water, CO2, CH4 and N2 which are apt to be recognized as impurities in the ozone generator. That is, the impurity removing unit may include: a water removing unit for removing water from the exhaust gas by adsorbing water using active alumina and zeolite; a CO2 and CH4 removing unit for removing CO2 and CH4 from the exhaust gas by adsorbing CO2 and CH4 using active carbon; and an N2 removing unit for removing N2 from the exhaust gas by adsorbing N2 using zeolite.
Further, the impurity removing unit may include at least one column-shaped adsorption tower; and the column-shaped adsorption tower may be sequentially charged with active alumina and zeolite used in the water removing unit, active carbon used in the CO2 and CH4 removing unit and zeolite used in the N2 removing unit from a bottom thereof to a top thereof.
Further, the impurity removing unit may further include a H2S removing unit 410 for removing H2S from the exhaust gas by injecting water.
Another aspect of the present invention provides an ozone-using system, which is provided with ozone treatment equipment to achieve a predetermined purpose, including the exhaust oxygen recycling apparatus for removing impurities from components included in an exhaust gas being discharged to the air after reaction in the ozone treatment equipment, the impurities being apt to be recognized as impurities in an ozone generator, and then supplying a refined exhaust gas to the ozone generator at a desired pressure.
The ozone-using system may be a water treatment system, a digestion system, a bleaching system, a disinfection system, a sterilization system or a semiconductor equipment system.
Meanwhile, the ozone treatment equipment may include an ozone contactor for bringing raw water into contact with ozone supplied from the ozone generator or may include a solubilization unit for solubilizing sludge discharged from an anaerobic digestion tank using ozone supplied from the ozone generator and then circulating the solubilized sludge into the anaerobic digestion tank.
The exhaust oxygen recycling apparatus for ozone treatment equipment according to the present invention is advantageous in that an exhaust oxygenic gas being discharged to the air after reaction in the ozone treatment equipment is refined, and then a refined exhaust gas is recycled to generate ozone.
The ozone-using system according to the present invention is advantageous in that ozone is generated using the oxygen provided by an exhaust oxygen recycling apparatus for ozone treatment equipment used in the fields of water treatment, digestion tanks, bleaching, sterilization, disinfection, semiconductor equipment systems and the like, and the generated oxygen is self-recycled. That is, when the ozone-using system is applied to a digestion system, it serves to improve the efficiency of reduction of sludge, when it is applied to a water treatment system, it serves to improve the taste of water, and when it is applied to a semiconductor equipment system, it serves to improve the cleanliness of the semiconductor.
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
Here, the components included in the exhaust gas change depending on the application field (for example, a water treatment system, a digestion system or the like) in which the ozone treatment equipment is used. For example, when ozone treatment equipment is applied to a digestion system, the exhaust gas includes O2, O2, N2, CO2, CH4, H2S and the like.
The impurity removing unit serves to remove water, N2, CO2, CH4, H2S and the like excluding O3 and O2 which are not apt to be recognized as impurities in an ozone generator. In the impurity removing unit, H2S is removed by injecting water, water is removed by adsorbing it using active alumina, zeolite or the like, N2 is removed by adsorbing it using zeolite or the like, and CO2 and CH4 are removed by adsorbing them using active carbon or the like.
Therefore, the impurity removing unit includes: a H2S removing unit 410 for removing H2S from exhaust gas by injecting water; a water removing unit 430 for removing water from exhaust gas by adsorbing water using active alumina and zeolite; a CO2 and CH4 removing unit 440 for removing CO2 and CH4 from exhaust gas by adsorbing CO2 and CH4 using active carbon; and an N2 removing unit 450 for removing N2 from exhaust gas by adsorbing N2 using zeolite.
The exhaust oxygen recycling apparatus 400 for ozone treatment equipment according to this embodiment, the constituents of which carry out the above-mentioned functions, respectively, is configured such that an H2S removing unit 410, the compressor 420, the water removing unit 430, the CO2 and CH4 removing unit 440 and the N2 removing unit 450 are sequentially provided from upstream to downstream. Meanwhile, the water removing unit 430, the CO2 and CH4 removing unit 440 and the N2 removing unit 450 may be provided in one column to conduct their respective functions. Here, the reason why the compressor 420 is provided upstream of the CO2 and CH4 removing unit 440 and the N2 removing unit 450 is because CO2, CH4 and N2 can be removed more efficiently when they are compressed.
Meanwhile, when ozone treatment equipment is applied to a water treatment system, exhaust gas may include N2, CO2, CH4, chloride components and the like which are apt to be recognized as impurities in an ozone generator as well as O3 and O2 which are not apt to be recognized as impurities. Therefore, the impurity removing unit may be configured such that N2, CO2, CH4, chloride components and the like can be removed. That is, the impurity removing unit according to this embodiment may be configured such that all of the impurities included in the exhaust gas can be removed in accordance with the application field of ozone treatment equipment.
The water removing unit 430 serves to remove the water injected to remove H2S or the water self-included in the exhaust gas in accordance with the application field of ozone treatment equipment, and the compressor 420 is used to compress the exhaust gas to a pressure at which the exhaust gas can be supplied to an ozone generator. A general ozone generator generates ozone using oxygen compressed to a pressure of 2.5˜3 bar. The compressor 420 of this embodiment may compress the exhaust gas to a pressure of 3.5˜4 bar in consideration of the pressure loss in the removing units 430, 440 and 450 upstream of the ozone generator such that the refined exhaust gas is supplied to the ozone generator while being compressed to a pressure of 2.5˜3 bar. However, the compressor 420 may also compress the exhaust gas to a pressure of less than 2.5 bar or more than 3 bar in accordance with the specifications of the ozone generator.
Each of the impurity removing units 520 according to this embodiment includes a column-shaped adsorption tower 521 and a plurality of control valves. The adsorption tower 521 is filled with adsorbents for adsorbing and removing CO2, CH4 N2 and the like. For example, alumina and zeolite 4A for adsorbing and removing water, active carbon for adsorbing and removing CO2 and CH4, and zeolite 13X for adsorbing and removing N2 may be sequentially charged in the adsorption tower 521 from the bottom thereof to the top thereof. Here, the amount of each of the adsorbents charged in the adsorption tower 521 may be determined depending on the components of the exhaust gas discharged after the reaction that takes place in the ozone treatment equipment. Further, the kinds of the adsorbents charged in the adsorption tower 521 may also be determined depending on the components of the exhaust gas discharged after the reaction in the ozone treatment equipment. That is, the kinds and amounts of the adsorbents charged in the adsorption tower 521 may be varied depending on the ozone-using system provided with the ozone treatment equipment.
When impurities are adsorbed and removed using the exhaust oxygen recycling apparatus 500, as shown in
As described above, preferred embodiments of the present invention are set forth to illustrate the present invention, and the scope of the present invention is not limited thereto.
Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
When the exhaust oxygen recycling apparatus for ozone treatment equipment according to the present invention is used in the fields of water treatment, digestion tanks, bleaching, sterilization, disinfection, semiconductor equipment systems and the like, ozone is generated using the oxygen provided by the exhaust oxygen recycling apparatus, and the generated oxygen can be self-recycled.
Number | Date | Country | Kind |
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10-2009-0116916 | Nov 2009 | KR | national |
10-2010-0120400 | Nov 2010 | KR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/KR2010/008535 | 11/30/2010 | WO | 00 | 8/20/2012 |