RU2636505C2 - Diaphragm electrolyser for purifying and disinfecting water - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: electrolyser for purifying and disinfecting water contains cylindrical electrodes vertically mounted in the dielectric sleeves, coaxially located relative to each other and coaxially located between the electrodes two microporous diaphragms forming an outer electrode chamber, an inner electrode chamber, and an average interdiaphragm chamber at the interelectrode space. Water is supplied through an inlet located in the lower end sleeve, simultaneously into all three chambers of the electrolyser. Water is drained through the outlets in the upper bushing. Clean water is drained through the outlet connected to the interdiaphragm chamber, and the flows flowing in the electrode chambers - through the outlets connected to them.

EFFECT: device provides the opportunity to simultaneously receive disinfected water purified from anions and cations, suitable for consumption without additional treatment and water with the anions and cations accumulated in it.

4 dwg

Description

The invention relates to installations for the electrochemical treatment of water and / or aqueous solutions and can be used in various fields of human activity for the purification and regulation of the properties of water and aqueous solutions.

Known installations of various designs for the treatment and purification of water with a single or multiple passage of water through a flowing electrolyzer (RU 2096337, publ. 11/20/97 [1]; RU 2038322, publ. 06/27/95 [2]; RU 2076847, publ. 10.04. 97 [3]; RU 2084408, publ. 07.20.97 [4]; RU 2091320, publ. 09/27/97 [5]; US 5427667, publ. 06/27/95 [6]; EP 0286233, publ. 12.10.88 [ 7]).

The disadvantages of the known devices are the use of two-chamber flow-through electrolyzers and, as a result, the relatively low degree of purification from heavy metal ions and anodic oxidation products, as well as the complexity of the design due to the need to use additional devices to remove active chlorine from the resulting water and remove the resulting hydroxides. In flowing two-chamber diaphragm electrolyzers, the aqueous solution being treated provides two flows: one to the anode, the other to the cathode. The separating microporous diaphragm interferes with the convection (and diffuse) exchange of electrically neutral molecules. At the same time, it is transparent for charged ions migrating in the electric field of the electrolyzer. Under the action of a voltage applied to the cathode and anode, the ions migrate to the corresponding electrodes. The diaphragm prevents the mixing of near-electrode solutions, leading to the fact that in the separated electrode spaces there is a dynamic accumulation of ions of different signs. A necessary condition for the operation of any flow diaphragm electrolyzer is the filling of its electrode chambers with electrolyte solutions. In this case, the supply of aqueous solutions to the two-chamber flowing electrolyzer for their processing can be carried out in parallel or in series. In a parallel processing scheme, when water is supplied directly to the input of the anode and cathode chambers, two products are obtained at the output: anolyte and catholyte, which is used for special needs. A sequential treatment scheme, when water sequentially flows through one, then through another electrode chambers, is used to purify and disinfect drinking water.

,

и другие (Сан. Пин. 2.1.4.1074-01 «Питьевая вода»). Содержание этих ионов колеблется в зависимости от источника воды, но общее их количество в питьевой воде достаточно для того, чтобы можно было проводить электрохимическую обработку с целью обеззараживания и очистки воды от органических загрязнителей, а также ионов тяжелых металлов путем катодного осаждения. В обрабатываемой воде при прохождении через электрическое поле межэлектродного пространства образуются сильнодействующие оксиданты, такие как

и

и другие, способствующие уничтожению (окислению, в том числе глубокому деструктивному окислению) многих молекул сложных органических веществ, в том числе циклического и гетероциклического строения с переводом их в более простые соединения.Water (potable or industrial) is subjected to electrochemical treatment, containing one or another amount of dissolved salts, and contains ions: Na ⁺ , K ⁺ , Ca ²⁺ , Mg ²⁺ , Fe ²⁺ ,

,

and others (San. Pin. 2.1.4.1074-01 "Drinking water"). The content of these ions varies depending on the source of water, but their total amount in drinking water is sufficient to allow electrochemical treatment to disinfect and purify water from organic pollutants, as well as heavy metal ions by cathodic deposition. In the treated water, strong oxidizing agents, such as

and

and others that contribute to the destruction (oxidation, including deep destructive oxidation) of many molecules of complex organic substances, including cyclic and heterocyclic structures with their translation into simpler compounds.

When using a two-chamber flowing electrolyzer for cleaning and disinfecting drinking water, the treated water is always treated in the anode chamber of this electrolyzer, comes into contact with the anode and accumulates the products of anode decomposition. Subsequently, with successive passage of water through the cathode chamber, the formation of hydroxides occurs, which also remain in the general stream. After this treatment, the water is disinfected, but untreated, because due to flow continuity, it contains anode and cathode treatment products. Such water is not ready for use, so subsequently it is necessary to introduce additional devices for its purification and filtration, which greatly complicates the equipment.

Closest to the claimed invention is a diaphragm electrolyzer, known from (RU 2038323, publ. 06/27/1995) [8]. The electrolyzer contains an external cylindrical anode coaxially mounted with respect to each other, an internal rod cathode, and a tubular microporous ceramic diaphragm located between the electrodes, separating the interelectrode space into the anode and cathode chambers. Each chamber has a separate entrance at the bottom of the cell and a separate exit at the top of the cell, communicating with the inlet and outlet hydraulic lines for the flow of water. The electrodes and the diaphragm are rigidly and hermetically fixed by means of sealing rings and end sleeves made of dielectric material. This electrolyzer is used as part of a plant for cleaning and disinfecting water, in which the treated water is supplied from a pressure source to the anode chamber of the electrolyzer. During the flow through the anode chamber, active chlorine is formed, destroying all microorganisms and oxidizing organic impurities. After exiting the anode chamber, water passes through a container with a catalyst, on which active chlorine is destroyed. Then water enters the cathode chamber of the electrolyzer, in which the organic impurities are reduced. Subsequently, water is supplied to the consumer. The disadvantage of this device is the low degree of purification from heavy metal ions, hydroxides and anodic oxidation products. Since the flow is continuous, from the point of view of material balance, the entire ionic composition of the water should be preserved, of course, with the exception of the part of the ions deposited on the cathode. Thus, chlorine passing through the catalytic reactor will lose its activity, but will remain in water. This significantly reduces its organoleptic properties. The disadvantage of the prototype lies in the fact that the process of water treatment in such devices is associated with the need for frequent stops due to overgrowth of the diaphragm and the surface of the cathode with hardness salts, which requires relatively frequent acid leaching of internal communications of electrochemical cells. Lengthening the operating time of such devices without acid washes leads to a decrease in the efficiency of their functioning.

The objective of the present invention is to simplify the design of a device for cleaning and disinfecting water, increasing the degree of water purification, increasing the biological value of drinking water resulting from the purification process,

For this purpose, a diaphragm electrolyzer for purifying and disinfecting water is proposed, which, like the known electrolyzer, contains vertically mounted in the dielectric bushings by means of sealing rings an outer cylindrical electrode, an inner cylindrical electrode, one of which is an anode, coaxially located and the other is a cathode, and a microporous diaphragm between them, through which the interelectrode space is divided into two electrode chambers - the outer and the inner.

The claimed electrolyzer is characterized in that it contains an additional microporous diaphragm, coaxially located between the electrodes, vertically mounted in dielectric bushings by means of sealing rings, forming an additional middle inter-diaphragm chamber between the electrode chambers, while in the lower end sleeve there is an inlet for the treated water, which supplies water simultaneously to all three chambers of the electrolyzer, and in the upper end sleeve there is an outlet for clean water connected to with a diaphragm chamber, as well as a water outlet connected to electrode chambers.

In the claimed three-chamber electrolyzer, part of the water coming from the water supply enters its middle chamber, and the other part of the water enters the anode and cathode chambers. Under the influence of electric current in all three chambers, the electrolysis process simultaneously begins. Active chlorine and its compounds are formed from salts, which make up the natural mineralization of any drinking water. The resulting oxidants disinfect, oxidize organochlorine and have a bactericidal effect on water. At the same time, under the action of a voltage applied to the cathode and anode, from the middle chamber through the diaphragms, the ions begin to migrate to the corresponding electrodes. Thus, excess metal ions and chlorine are removed from the water in the middle chamber. The process is regulated by the magnitude of the voltage supplied to the electrodes, and the speed of the water flow. In the anode chamber, a concentration of chlorine ions occurs, in the cathode chamber - ions of heavy metals. The water from the middle chamber is purified, disinfected, suitable for consumption without additional treatment and has good organoleptic properties, tastes good in the absence of chlorine odor. Thus, the three-chamber electrolyzer allows you to get suitable for consumption water without additional treatment.

To obtain additional properties of the treated water, the claimed electrolyzer can be used as part of installations for cleaning and disinfecting water, as well as giving it special properties. For this, the installation uses at least one additional two-chamber reactor. The hydraulic circuit is organized as follows. After leaving the middle chamber, water can pass through the cathode chamber of an additional two-chamber electrolyzer, and flows from the electrode chambers are directed to the anode chamber of the two-chamber electrolyzer. In the cathode chamber of an additional two-chamber electrolyzer, the redox potential (ORP) is shifted to a level corresponding to the internal environment of the human body. As a result, the biological value of water increases, its ability to penetrate the biological membranes of cells and participate in metabolic processes.

The use of a three-chamber electrolyzer with an average water purification chamber independent of the location of the electrodes allows the use of a reverse mode, with a change in the polarity of the electrodes after certain periods of time. In this case, the electrode chambers are interchanged. This ensures self-cleaning of the diaphragms from particles clogging them, increases the removal of deposited salts. Those. You can not use dangerous acidic methods of cleaning salts of hardness, which are mandatory for all other plants.

A new technical result achieved by the claimed three-chamber electrolyzer is to simultaneously obtain purified water from anions and cations and disinfected water suitable for consumption without further treatment, and water with anions and cations accumulated in it as a target product.

The invention is illustrated by drawings, where in FIG. 1 shows the design of the claimed diaphragm three-chamber electrolyzer; in FIG. 2 is the same, in section, in FIG. 3 - the same in the form of a diagram; in FIG. 4 is a diagram of the use of the claimed three-chamber electrolyzer in combination with a two-chamber electrolyzer.

The electrolyzer contains an external cylindrical electrode 1 (cathode or anode) coaxially mounted with respect to each other, an internal cylindrical electrode 2 (anode or cathode), between which two tubular microporous ceramic diaphragms 3 and 4 are installed coaxially with respect to the electrodes. and the diaphragms form the electrode chambers: the outer electrode chamber 5 and the inner electrode chamber 6. The diaphragms form a middle - inter-diaphragm chamber 7 located between them.

Structurally, the electrodes and diaphragms are mutually fixed in the end bushings made of dielectric material, the upper sleeve 8 and the lower sleeve 9 using the sealing rings 10 and 11, as well as nuts 12, screwed onto the threaded ends of the inner electrode. In the lower sleeve 9 there is an inlet 13 for the treated water, which distributes the water into the chambers 5, 6 and 7 through the openings 14, 15, 16. In the upper sleeve 8 there is a clear water outlet 17 connected through the hole 18 to the inter-diaphragm chamber 7, and water outlet 19 connected to chambers 5 and 6 through openings 20, 21.

The electrodes of the electrolyzer can be made of titanium, coated titanium, graphite, stainless steel and others, depending on the operating conditions, which are determined by the purpose of the electrolyzer. The diaphragms of the electrolyzer are made of ceramic and are ultrafiltrational, which ensures that at equal pressures in the chambers there is no filtration flow in the presence of ion exchange.

Three-chamber cell operates as follows. The treated water is supplied from a pressure source immediately to all three chambers of the electrolyzer. After applying voltage to the electrodes, during the flow of water through the chambers, the electrolysis process begins. In the electrode chambers, depending on the potential of the electrode, ions accumulate: in the anode chamber — anions (chlorine, oxygen, etc.) in the cathode chamber — cations (alkali ions, heavy metals, etc.) Functionality of the electrode chambers is determined by the sign of the voltage potential supplied to the electrode and may change during operation. Accordingly, in the middle chamber, which is essentially bipolar, both the cathodic and anodic processes simultaneously occur. Active chlorine is formed, destroying all microorganisms and oxidizing organic impurities. At the same time, to ensure electrical conductivity, there must be an electromigration movement of ions. When a negative potential is applied to the internal electrode and a positive potential to the external electrode, they can be respectively defined as the cathode and anode. In this case, cations, including heavy metal ions, from the middle chamber migrate to the cathode chamber 6 through the diaphragm 3, and anions, including chlorine, pass into the anode chamber 5 through the diaphragm 4. Moreover, if the polarity of the electrodes is vary, the process will be essentially the same: cations - to the cathode, anions to - the anode. The main thing is that in the process of electrolysis, active chlorine is formed, which oxidizes the organic matter and has a bactericidal effect. At the same time, electromigration leads the ions to the electrode chambers from the middle chamber through microporous ceramic diaphragms, which do not allow mixing of the flows. Thus, the flow of water flowing in the inter-diaphragm chamber is disinfected and purified from chlorine and heavy metal ions. Streams flowing in the electrode chambers 5 and 6 accumulate: anodic - chlorine, cathodic - heavy metal ions. After leaving the electrode chambers 5, 6, the solutions are used for household needs or are removed to the drainage. Water from the middle chamber, purified and disinfected, is supplied to the consumer.

The claimed electrolyzer can also be used as part of water treatment plants, for example, in a plant where the water flow is sequentially processed in a three-chamber electrolyzer and then in a two-chamber electrolyzer.

In such an installation, the water after treatment from the anode and cathode chambers of the three-chamber electrolyzer through the mixer enters the anode chamber of the two-chamber electrolyzer, and water from the middle chamber of the three-chamber electrolyzer goes into the cathode chamber of the additional two-chamber electrolyzer. In the cathode chamber of an additional two-chamber electrolyzer, direct electrochemical reduction of the remaining organic impurities, removal of anions and remaining heavy metal ions can occur. And most importantly, there is a shift in the redox potential of water to a level corresponding to the internal environment of the human body. As a result, the biological value of water increases, its ability to penetrate the biological membranes of cells and participate in metabolic processes. Subsequently, the products of the anode treatment go into drainage or are used as liquid for household needs, and the products of the cathode treatment are delivered to the consumer.

Thus, the claimed invention allows to simplify the design of the device for cleaning and disinfecting water, to increase the degree of purification, as well as the biological value of the resulting drinking water.

Claims (1)

A diaphragm electrolyzer for cleaning and disinfecting water, containing vertically mounted in dielectric bushings with sealing rings, an outer cylindrical electrode, an inner cylindrical electrode, one of which is an anode and the other is a cathode, and a microporous diaphragm between them, coaxially arranged whereby the interelectrode space is divided into two electrode chambers - the outer and the inner, characterized in that the electrolyzer contains vertically additional microporous diaphragm coaxially located between the electrodes installed in the dielectric bushings by means of o-rings, which forms an additional middle inter-diaphragm chamber between the electrode chambers, while in the lower end bushing there is an inlet for the water to be treated, which supplies water to all three chambers of the electrolyzer at the same time, and in the upper the end sleeve has an outlet for clean water connected to the inter-diaphragm chamber, as well as a water outlet connected to the electrode E cameras.

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