Field of the invention

The present invention relates to an apparatus for treatment of water, the apparatus comprising an inlet tube for entry of water to be treated, an outlet tube for discharging treated water, the inlet tube and the outlet tube being interconnected be means of a connecting pipeline, and further a blending device arranged within the connecting pipeline between the inlet tube and the outlet tube, and an O3 generator having its outlet opened into the blending device.

Background of the invention

Apparatuses for producing ozonated water, which are known in the art, comprise a water receptacle provided with an inlet opening for connecting a supply line leading from an active oxygen generator (O3) fed by an air drier. A particular disadvantage of the aforesaid technical solution consists in that it does not enable any efficient elimination of other impurities, such as pesticides, hormones or the like, to be accomplished.

Furthermore, the document US 6391191 discloses an apparatus for treatment of water, comprising a water collecting receptacle having an inlet opening into which an outlet pipeline of an activated oxygen generator opens. The latter receptacle is connected with a glass for collecting treated water, the connection being realized through a pump and a carbon filter. The drawbacks of the letter apparatus consist in the necessity of using a pair of receptacles, impossibility of establishing an automatic recirculation of treated water through the apparatus, a limited degree of water purification and a generally low functional variability.

Summary of the invention

The above drawbacks of the prior art are largely eliminated by the apparatus for treatment of water for treatment of water, comprising an inlet tube for entry of water to be treated, an outlet tube for discharging treated water, the inlet tube and the outlet tube being interconnected be means of a connecting pipeline, a blending device arranged within the connecting pipeline between the inlet tube and the outlet tube, and an O3 generator having its outlet opened into the blending device. According to the invention, the apparatus further comprises a filter arranged within the connecting pipeline and containing activated charcoal and/or a catalyst for inducing formation of OH radicals, and an alkalizer for raising the pH value of treated water, said alkalizer being arranged within the connecting pipeline and/or within the filter.

According to a preferred embodiment the apparatus further comprises a bypass pipeline for bypassing the filter, and a valve for selectively leading treated water through the filter and/or through the bypass pipeline.

Preferably, the apparatus further comprises a receptacle, into the inner space of which the inlet opening of the inlet tube and the outlet opening of the outlet tube are introduced. It is also advantageous, when the apparatus further comprises a lid for closing the receptacle, the lid being preferably supplemented with an O3 destructor and with a blow-off pipeline, which has its inlet connected to the upper portion of the interior space of the receptacle and its outlet connected to the O3 destructor.

Apparatus according to the invention preferably further comprises a source of dry gas, which contains oxygen, the outlet of said source being connected to the inlet of the O3 generator. The source of dry gas is preferably selected from the group consisting of a passage capsule containing a desiccant, a passage capsule containing a molecular screen, a passage capsule containing a desiccant and a molecular screen arranged in the outlet portion of the capsule, a pressure vessel containing dry air and a pressure vessel containing oxygen.

The apparatus further comprises a circulation pump arranged within the connecting pipeline between the inlet tube and the outlet tube.

The apparatus may further comprise a static mixer arranged within the connecting pipeline between the blending device and the outlet tube.

The apparatus preferably further comprises a safety device for detecting presence of water to be treated.

Considering possible variability of treatment of water it may be advantageous, when the apparatus further comprises a source of CO2 for blasting CO2 into the connecting pipeline between the inlet tube and the outlet tube, or into the outlet tube, or into the receptacle. The catalyst for inducing the formation of OH radicals, a layer of activated charcoal and the alkalizer are successively arranged within the filter preferably in the above order in the flow direction of the liquid.

The alkalizer is preferably arranged downstream of the catalyst for inducing the formation of OH radicals and/or downstream of the activated charcoal with respect to the flow direction of treated water.

An advantageous embodiment of the apparatus further comprises a cation exchange device arranged within the bypass pipeline. Brief description of drawings

For more detail, the present invention will be further described with reference to the accompanying drawings showing exemplifying embodiments, wherein Fig. 1 a shows the first exemplifying embodiment of the apparatus for treatment of water, Fig. 1 b shows the second exemplifying embodiment, Figs. 2A and 2b show selected portions of further exemplifying embodiments and Figs. 3a, 3b, 3c schematically show preferred embodiments of the filter.

Exemplifying embodiments of the invention

The exemplifying embodiment of the invention, which is shown in Fig. 1 a, comprises a receptacle 1 for collecting water to be treated / purified. The receptacle 1 is closed by means of a lid 12. An inlet tube 2 extends into the interior space of the receptacle 1 to draw water to be purified.

The inlet tube 2 is connected both to a filter 3 containing a catalyst 16 for inducing formation of OH radicals and an alkalizer 18 and to a bypass pipeline 13 for bypassing the filter 3. The bypass pipeline 13 and the filter 3 are fluidly

interconnectable with a blending device 7 via a valve 4 (preferably in the form of an electric valve), wherein an outlet of a generator 6 for producing O3 (activated oxygen, i.e. ozone) vents into the blending device.

The inlet of the generator 6 for producing O3 is interconnected with an outlet of a source 5 of dry gas containing oxygen.

The outlet of the blending device 7 is connected to a static mixer 9 for increasing solubility of gases in water, the connection being provided via a circulation pump 8. The outlet of the mixer 9 opens into an outlet tube 10 for returning treated water into the receptacle 1.

An inlet of a blow-off pipeline extends into the upper portion of the interior space of the receptacle 1 , the outlet of blow-off pipeline opening into a destructor 11 for eliminating residual O3 contained in the gas to be exhausted. The destructor 11 for eliminating residual O3 contains, for example, activated charcoal or another substance that is usable for destroying O3 contained in gases.

The apparatus shown in Fig. 1a works in the following manner:

The receptacle 1 is filled with water to be purified. Subsequently, the receptacle 1 is closed by means of the lid 12. The valve 4 will assume a position for closing the connection between the filter 3 and the blending device 7 and for connecting the bypass pipeline 13 with the blending device 7. The circulation pump 8 is actuated, so that water is aspirated via the inlet tube 2, the bypass pipeline 13, valve 4 into the blending device 7. Simultaneously, the generator 6 for producing O3 is actuated, so that O3 is fed into the blending device 7. Subsequently, water enriched with O3 is led through the circulation pump 8, which causes a further intensive blending and an additional increase in pressure, and further into the static mixer 9 where a still further intensive blending process takes place. Pressurized water enriched with dissolved O3 is led through the outlet tube 10 from the static mixer 9 into the receptacle 1. Thereby, water contained in the receptacle 1 is mixed with treated water being introduced.

Advantageously, the lid 12 is attached to the receptacle 1 in an airtight manner. Due to this, that portion of O3, which has not been dissolved in water and hence reaches the water surface, can be led through the blow-off pipeline into the destructor 11 for eliminating residual O3. The gas / air leaving the destructor will be free from O3.

Neither the lid 12 nor the destructor 11 for eliminating residual O3 is essential for the basic function of the apparatus according to the invention. Advantageously, the receptacle 1 is removable.

Ozonated water is prepared by the above process and such water is usable, for example, for surface disinfection, washing fruits and vegetables or the like.

In order to increase the efficiency of water purification or to remove another type of impurities, the above process can be continued in that the position of the valve 4 is changed, so that the outlet tube 2 is connected via the filter 3 to the blending device 7 and no water flows through the bypass pipeline 13. Thus, the inlet tube 2 leads water enriched with activated oxygen from the receptacle 1 into the filter 3 where the formation of OH radicals takes place. This means that water is purified in a so-called advanced oxidation process (known as AOP). Owing to the fact that water already contains a high proportion of O3, the filter is particularly efficient during the formation of OH radicals. Furthermore, the filter 3 increases the pH value by means of the alkalizer 18. Water leaving the filter 3 is led into the blending device 7 where it is additionally enriched with O3. Subsequently, water flows through the circulation pump 8 and the static mixer 9 and via the outlet tube 10 into the

receptacle 1. Again, water is aspirated via the inlet tube 2 out of the receptacle.

Owing to the raising pH value, the efficiency of the transformation of O3 into OH radicals is improved.

Alternatively, the valve 4 can assume a position causing the entire quantity of water to flow through the filter 3 immediately at the beginning of the purification process (i.e., to suppress the initial circulation through the bypass pipeline 13). In the latter case, the initial efficiency of the filter 3 has a low or zero level in terms of the formation of OH radicals. Nevertheless, water enriched with activated oxygen and having an increased pH value will reach the receptacle 1 in a short time causing a rapid improvement of the efficiency of the filter 3 in terms of the formation of OH radicals during the subsequent stage of the process.

If the bypass pipeline 13 (and the valve 4) is not used at all, the entire quantity of treated water will always flow through the filter 3.

In case that the apparatus serves as a purification device for preparing drinking water, it is advisable to switch off the O3 generator 6 or to shut down the supply of O3 into the blending device 7 in the final stage of the purification process. Thereby, water aspirated from the receptacle will flow through the filter 3 wherein O3 is used for inducing the formation of OH radicals. Shortly afterwards, water contained in the receptacle 1 will become completely free of O3 and, in addition, pesticides, hormones and other impurities will be eliminated from it.

Advantageously, the filter 3 contains activated charcoal 17. According to another advantageous embodiment, the filter may also contain a heterogeneous catalyst 16, preferably in the form of a layer consisting of various metal oxides. The catalytic efficiency of metals depends on the physical and chemical properties of the same. The physical properties include the surface area and the size of the pores, as well as the surface charge. The principal chemical properties include the chemical stability and the active surface area. Heterogeneous catalysts include, for example, AI2O3, MnOa, TiOa, ZnO and FeOOH.

According to the aforesaid preferred embodiment, the filter 3 contains the alkalizer 18 for raising the pH value of treated water. Alternatively, the alkalizer 18 can be arranged within the water circuit, thus constituting a separate unit located outside the filter 3, e.g. a separate alkalising unit. Advantageously, the alkalizer 18 may contain calcium, magnesium, sodium and/or potassium ions and assume, for example, the form of pellets / globules.

According to a particularly advantageous embodiment, the pH value of treated water is raised to a value in the range of 8 - 10. A pH level falling into that range enables the highest rate and efficiency of the transformation of ozone into OH radicals to be achieved and, besides that, water having such pH level is considered to be most suitable for drinking.

Some types of activated charcoal are able to induce the formation of OH radicals and thus can be considered to constitute a catalyst 16. Therefore, the filter 3 may contain either a single type of activated charcoal or another particular type of the catalyst 16 (Fig. 3a). In the latter case, the alkalizer 18 is arranged within the connecting pipeline but outside the filter 3. According to a more advantageous embodiment, the filter 3 contains a number of homogeneous layers, such as a layer consisting of activated charcoal 17 (with a low or no catalytic effect but with distinct sorption properties), a catalytic layer 16 for inducing the formation of OH radicals and, finally, an alkalising layer 18. Thereby, water is brought in contact with the catalyst 16, with the layer composed of activated charcoal 17 and with the layer composed of the alkalizer 18 in the given order (Fig. 3b). According to the most advantageous embodiment (as shown in Fig. 3c), the filter 3 the filter is also constituted by a number layers, wherein the first layer comprises a mixture of several catalysts 16, the following layer contains activated charcoal 17 and the last layer contains the alkalizer 18. Thereby, an optimal utilization of the dissolved ozone in advanced oxidation processes can be achieved.

As shown in Fig. 1 b, both the inlet tube 2 and the outlet tube 10 can also be introduced into the receptacle 1 from below or in a lateral direction.

The valve 4 is advantageously formed by a three-way electric valve but it can be also replaced with a pair of valves. It is obvious that the location of the valve can be altered, provided that its function will not be affected. The latter function consists in preventing aspirated water from flowing through the filter 3. This means that the valve 4 can be located, for example, in a point where the inlet tube is branched into the pipeline leading to the filter 3 and the bypass pipeline 13. Alternatively, the valve 4 can be arranged within a pipeline opening into the filter 3 or leading out of the filter 3.

According to another alternative embodiment, the valve 4 can be arranged within the bypass pipeline 13. In the latter case, a certain proportion of water flows through the filter 3 even when the valve 4 is in the open position. However, the flow rate of water led through the bypass pipeline 13 is significantly higher which is due to the fact that the filter 3 presents a significantly higher resistance in comparison with the bypass pipeline 13.

In general, it may be useful to ensure that a certain proportion of water flows through the filter 3 even in a case where merely the ozonation of water is required, i.e. where the filtration or the formation of OH radicals would be superfluous.

Thereby, the functionality of the filter 3 is ensured even in the case that the apparatus according to the invention is used merely for the preparation of ozonated water in a long term.

It is a generally known fact that the efficiency of the generator 6 for producing O3 increases with decreasing humidity of the gas / air fed into the apparatus.

Advantageously, the source 5 of the dry gas containing oxygen can be constituted by a pressure vessel for collecting pressurized dry air or oxygen or by an air drier. The air drier can be selected from the group comprising a passage capsule containing a desiccant, such as silica gel, a passage capsule containing a molecular screen or a passage capsule containing a desiccant supplemented with a molecular screen arranged in the outlet portion of the capsule.

Such an air drier can be advantageously realized in the form of

interchangeable capsules. Permanent, regenerative air driers having an automatic control function are also usable.

Advantageously, the air drier has a sealable inlet.

The efficiency of the air drier, or the necessity of regenerating or changing the capsule, can be monitored by means of an electric sensor. Alternative monitoring methods may include visual inspections (e.g. those based on the change in the colour of silica gel) or measuring the time of operation of the air drier or O3 generator 6 elapsed since the last change or regeneration of the respective capsule.

The presence of the source 5 for supplying a dry gas is not essential for the functionality of the apparatus according to the invention. Nevertheless, it is

considered to be advantageous.

It is obvious that the circulation pump 8 can be alternatively arranged in virtually any location within the given circuit, i.e. upstream of the blending device 7, or immediately at the outlet end of the inlet tube 2, or at the inlet end of the outlet tube 10, or the like.

Another possible embodiment consists in that the blending device 7 is arranged, along with the O3 generator 6 attached thereto, immediately downstream of the inlet tube 2.

The static mixer 9 can be constituted, e.g., by a tubular member comprising an array of partitions, by perforated plates etc. Nevertheless, the presence of the static mixer 9 is not essential for the functionality of the apparatus according to the invention.

According to a particularly advantageous embodiment, the apparatus according to the invention comprises a safety device (not shown) for detecting absence of water in the receptacle 1 before the beginning of the purification process or, as the case may be, during the process. The detection of the empty state of the receptacle causes that the purification process is prevented from being started or is suspended. The safety device may comprise a pair of electrodes for determining the electric conductivity of the environment therebetween, the conductivity being significantly higher in a receptacle containing water when compared to that containing air. Such electrodes can be arranged inside the receptacle 1 during the operation of the apparatus. For example, one electrode can constitute a part of the inlet tube 2 and the other one can constitute a part of the outlet tube 10. Alternatively, the safety device can monitor the presence of water within the circuit, i.e. in any point of the connecting pipeline between the inlet tube 2 and the outlet tube 10. For example, such a safety device can be constituted by a pair of electrodes arranged within the given circuit (preferably upstream of the valve 4).

In yet another preferred embodiment, the apparatus according to invention comprises the source 14 of CO2, preferably in the form of a small pressure vessel, said source opening into the circuit in a manner enabling CO2 to be introduced into the liquid contained in the receptacle. In such case, the operation of the apparatus according to the invention will have two stages: first, water contained in the receptacle will be purified by the apparatus in order to achieve the drinking water quality; subsequently, CO2 supplied by the source 14 will be introduced into the receptacle. The above apparatus can also be used for preparing carbonated water directly from drinking water, i.e. without any prior purification.

The source 14 CO2 can advantageously open into the pipeline interconnecting the source 5 of the dry gas with the O3 generator 6, said interconnection being preferably realized by means of an electric valve (Fig. 2a). Alternatively, a separate valve can be assigned to each of the aforesaid sources 5, 14.

Advantageously, the source 14 of CO2 can open (through an outlet valve) into the pipeline interconnecting the O3 generator 6 with the blending device 7 (Fig. 2b).

According to yet another embodiment, the source 14 of CO2 can open into the static mixer 9 or into a point upstream of the latter. Alternatively, the source 14 of CO2 can open into the receptacle via a separate interconnecting pipeline (not shown).

According to a further advantageous embodiment, a unit comprising a cation exchanger (catex) can be arranged within the water treatment circuit, preferably within the bypass pipeline 13 for bypassing the filter 3 or within a still another, separate bypass pipeline, the latter enabling water to be delivered from the inlet tube 2 into the blending device 7 through the cation exchanger but not through the filter 3 or, at least, not through the alkalizer 18. The passage of treated water through the cation exchanger causes the pH value of the same to drop, thereby prolonging the period of efficiency / decomposition of O3 in water. Thus, the apparatus can be used for producing ozonated water having a relatively high ozone content over a longer period of time. Depending on the pH value, which is required to be achieved, a moderately or strongly acidic cation exchanger can be selected.

In case that the cation exchanger is arranged within the bypass pipeline 13, it is preferable to have the alkalizer 18 inside the filter 3 or within the respective pipeline upstream or downstream of the filter. When the objective of the treatment process is to provide drinking water, the respective flow is directed through the bypass pipeline 13 into the blending device 7 and, subsequently, through the pump 8, the static mixer 9 and the outlet tube 10 into the receptacle 1 , thereby causing the pH value of treated water to drop and ozonation of the same is provided. Afterwards, the valve 4 is switched over, thereby causing treated (ozonated and acidized) water to be delivered 1 through the filter 3 containing, among others, the alkalizer 18 for raising the pH value of water, and further through the blending device 7, the pump 8 and the static mixer 9 into the outlet tube 0 opening into the receptacle. In this manner, the pH value of treated water is gradually raised which means that the water treatment process based on the formation of OH radicals takes place under conditions of a gradually raising pH value. Owing to the fact that the water treatment process takes place at various / varying pH values, optimal conditions for water treatment eliminating a wide range of various contaminants can be established.

In an advantageous embodiment, the apparatus according to the invention comprises a control unit (not shown) that controls the operation of the valve 4, the O3 generator 6 and the pump 8 and monitors the efficiency of the drier along with the operations of the safety device, the outlet valve of the source 14 for delivering CO2 or other possible components. Advantageously, the control unit is interconnected with a display and with an input interface for entering the required parameters of treated water.