WO2009070056A1 - Device for electrochemically treating water or aqueous solutions - Google Patents

Abstract

The invention relates to electrochemically treating water and/or salt aqueous solutions with the view to modifying oxidising and reducing properties thereof. The inventive device comprises an inner electrode (1) with blind axial holes (2), which are provided with an inside thread, and an external electrode (3) coaxial to said inner electrode. A semipermeable diaphragm (4) which divides an annular cavity into internal (5) and external (6) chambers is placed between the electrodes. The external chamber (6) is provided with input and output pipe sockets (7', 7'') which communicate with the chamber (6) via a hole in this electrode. The internal chamber (5) has axial input and output pipe sockets (8' 8'') with internal axial blind holes (9', 9''). A cylindrical projection (10) with an external thread for interacting with the threaded hole (2) on the end face of the inner electrode (1) is made on the closed end face of the pipe socket (8' 8'') oriented inside the device. The device has identical end lids each of which consists of two parts (11, 12). The outwardly oriented part (12) of the combined lid is pressed by the projection on the pipe socket (8' 8'') together with a washer (13). A current conductive electrode (14) is clamped between the washer (13) and the outer surface of the lid. A second current conductive electrode (15) is secured on the external electrode (3). The inwardly oriented part (11) of the lid is in the form of a dielectric bush and has channels (16), by means of which the axial holes in the pipe sockets (8' 8'') communicate with the internal cavity (5) via holes (17) provided in the side walls of said pipe sockets. The channels (16) are positioned in radial planes and, preferably, are oriented at an angle to the device axis.

Description

 DEVICE FOR ELECTROCHEMICAL PROCESSING OF WATER OR AQUEOUS SOLUTIONS FIELD OF THE INVENTION The invention relates to the field of electrochemical treatment of water and / or aqueous solutions of salts in order to change their oxidizing, reducing and structural properties. The invention can be used for purification, disinfection, structuring and conditioning of water, cathodic softening of water, as well as for disinfecting, washing, sterilizing, preserving, bleaching, prophylactic solutions and solutions that eliminate odors.

BACKGROUND OF THE INVENTION A device for electrochemical water treatment is known [RF Patent 2297981, publ. 10.21.2005, FIG. 3], which incorporates an outer electrode in the form of a hollow cylinder and an inner rod composite electrode coaxial to it. The annular cavity between the electrodes is divided by a coaxial partition into external and internal chambers equipped with inlet and outlet nozzles. The design has a lower base and an upper end cover. The connection of the base with the electrodes is carried out using bolts. The upper end cover is connected to the inner electrode by means of a hollow bolt, which at the same time is the outlet pipe for the inner chamber, to which it is connected by channels radially passing through the inner electrode. The main drawback of the design is the lack of unification of the end elements, which complicates its manufacture. The device is deprived of this drawback - a flowing electrochemical modular element for processing liquid [RF patent 2145940, publ. 02.27.2000], which incorporates, as in the analogue described above, an inner rod electrode, an outer electrode, a partition dividing the cavity into an inner and outer chamber, each of which has an inlet and outlet nozzles that are mounted on the end dielectric bushings , the same design for both ends. The assembly of the structure was carried out using bolts screwed into the ends of the internal electrode. Despite the relative unification, the main drawback remains the relative complexity of the design, since the nodes for input / output of fluid into the inner chamber and into the outer chamber are different from each other, and the design provides for additional end fastening elements. Another disadvantage is that the supply and removal of the processed fluid is carried out by radial lateral pipes, which necessitates additional supply using bent pipes (elbows) for installation in a linear highway.

As a prototype, a device for electrolytic water treatment was selected [RF Patent 2132821, publ. 07/10/1999]. The vertical flow-through electrolyzer incorporates an inner hollow electrode, an outer electrode and a baffle separating the annular cavity into the inner and outer chamber. At both ends of the device there is a dielectric sleeve, which is closed by a dielectric block, made similar to a union nut. The supply and removal of the processed fluid to the inner chamber is carried out by radial end pipes - fittings that are screwed onto the ends of the inner electrode. At the same time, these fittings are fixing elements. The design of the prototype allows you to mount a flowing electrolyzer in the line of the processed fluid without the use of elbow bends. The main drawback of the design is the fragility of the internal electrode. This is because there are through holes in the wall of the inner electrode through which the cavity of the electrode communicates with the inner electrolysis chamber. In electrolyzers, two types of electrodes are usually used: metal with a coating of metals of the platinum-iridium group, or graphite. When an electrode is made of metal, the presence of holes violates the integrity of the protective coating on the inner electrode, which leads to electrochemical corrosion of the electrode body when it comes in contact with an aggressive environment. When the internal electrode is made of graphite, the presence of holes in the tubular structure increases the fragility of the electrode. In both cases, the service life of the internal electrode is significantly reduced compared to integral electrodes (without holes in the side walls)

Thus, there is a technical contradiction: some devices are reliable, but have an excessive number of structural elements - separately for supplying / discharging fluid and, separately, fasteners, for example, end bolts; other devices, for example, a prototype, are relatively simpler because they have elements combining the functions of fasteners and fluid inlet / outlet, but such devices have a limited service life and require frequent replacement of internal electrodes. Disclosure of invention

The basis of the invention is the task to solve the contradiction, and to create a new device for the electrochemical treatment of water or aqueous solutions. Achievable technical result - increased reliability

(long-term operation of the device without replacing the internal electrode) while maintaining the possibility of coaxial connection to the processed fluid line without using elbow bends (direct connection).

The problem is solved in that the device for the electrochemical treatment of water or aqueous solutions includes end caps, an external tubular electrode, inside of which an internal electrode is coaxially located. The annular cavity between the electrodes is divided by a coaxial semipermeable diaphragm into an inner chamber and an outer chamber. Each chamber is equipped with an inlet and outlet pipe, while the inlet and outlet pipe of the inner chamber are made axial. These nozzles are connected to the internal electrode by a threaded connection and fix the position of the end caps. The device differs from the prototype in that openings are made in the side walls of the axial nozzles, which communicate with the inner chamber through channels. These channels are made in the end caps and are oriented in radial planes. It is preferable that the inner electrode be formed with a rod electrode with blind threaded holes at the end to form a screw pair with an axial nozzle, which in turn is provided with a threaded portion on the outer surface.

More technological is the execution of end caps prefabricated, consisting of two parts and the implementation of the channels in the parts facing inward.

Channels oriented in radial planes can be perpendicular to the axis of the device, and can be oriented to it at an angle. An embodiment of the invention

In more detail, the invention is illustrated by the implementation example described below and is illustrated by the Figure, which shows a longitudinal section of the device. The device comprises an internal electrode 1, for example, in the form of a rod of cylindrical shape with end blind axial holes 2 with internal thread. A hollow cylindrical (tubular) outer electrode 3 is installed coaxially with the inner electrode 1. A semipermeable diaphragm 4 is installed coaxially between the electrodes, separating the annular cavity into the inner chamber 5 and the outer chamber 6. The outer chamber 6 has an inlet and an outlet pipe T and 7 ", respectively, which are radially mounted on the outer electrode 3 and communicate with the chamber 6 through the holes in this electrode. The inner chamber 5 has axial inlet and outlet nozzles (fittings) 8 'and 8 "with internal axial through holes 9 'and 9 ", respectively. On the closed end of the pipe 8', facing the inside of the device, there is a cylindrical protrusion 10 with an external thread for interaction with the threaded hole 2 on the end of the inner electrode 1. A similar protrusion is on the closed end of the pipe 8".

The device has end caps identical to each other at both ends. More technologically advanced is the design in which each end cover consists of two parts 1 1, 12. The outward facing part 12 of the assembly cover is pressed by a protrusion (expanding part, flange) on the pipe 8 '(8 "), which acts as a bolt head, and a washer 13. Between the washer 13 and the outer surface of the lid, a current-conducting electrode is clamped 14. A second current-conducting electrode 15 is fixed to the outer electrode 3.

The inward portion of the lid 11 is the dielectric sleeve and has channels 16, through which axial holes in the nozzles 8 '(8 ") through the holes 17 in the side walls of the nozzles communicate with the internal cavity 5. The channels 16 are located in radial planes and, preferably, are oriented at an angle to the axis of the device, and therefore, to the axis of the internal cavity and to the axis of the hole 9 '(9 ") of the nozzle, which reduces hydraulic losses. To prevent direct flow of liquids between chambers 5 and 6, o-rings 18 are installed at the ends of the diaphragm 4. The tightness of the device as a whole is achieved by means of o-rings 19 installed between the covers and in contact with the outer surface of the nozzles 8 '(8 ") and on the other sides with the inner surface of the outer electrode

3.

The operation of the device is illustrated by the following examples, in which the current supply is implemented in such a way that the inner electrode is the anode and the outer electrode is the cathode.

The processed fluid is supplied to the pipe 8 ', and the treated liquid (anolyte) is discharged from the 8 "pipe. Depending on what properties the solution is to be obtained, water and / or various saline solutions are supplied to the device. The pipe T is designed to supply the processing liquid, for example, saline, pipe 7 "- for the removal of saline (catholyte). T and 7 "nozzles can be combined into a single external closed loop (with replenishment of the active substance). Example 1.

To obtain anolyte and catholyte in the pipe 8 'serves 1% solution of sodium chloride. Through holes 17 and channels 16, the solution enters the inner electrode chamber 5. A voltage is applied to the electrodes. Under pressure, the solution through a semipermeable diaphragm 4 enters the external electrode chamber 6. During operation of the device, two oppositely charged ion flows form on the external and internal surfaces of the diaphragm 4, a potential difference arises between the flows, which leads to an increase in the electric field strength in the diaphragm, as a result the mobility of ions in the pores of the diaphragm increases and the electrical resistance of the device decreases. As a result, an electroactivated solution is formed - anolyte, which is discharged through the channels in the lid and the 8 "pipe. A 1% sodium chloride solution can also be supplied through the pipe 7 '.

Example 2

To obtain a disinfectant solution, water is supplied through the pipe 8 ', which enters the internal electrode chamber 5, as described above. At the same time, 30% sodium chloride solution is supplied through the pipe T, which circulates in an external closed circuit passing through the external electrode chamber 6. Water , entering the internal (anode) electrode chamber, under the influence of redox processes occurring in both chambers, it is saturated with hypochlorous acid ions, short-lived oxygen radicals, small PWM amount of ozone and chlorine dioxide due to the migration of ions from the outside (cathode) of the electrode chamber and discharged through a branch pipe 8 "in the form of a disinfecting solution.

Example 3

To obtain a disinfectant solution, 1-20% sodium chloride solution is supplied through the T pipe, which enters the external cathode chamber, then the solution exits the 7 "pipe and through the pipe 8 'enters the inner electrode chamber. The solution entering the internal (anode) electrode chamber under the influence of redox processes occurring in both chambers is saturated with hypochlorous acid ions, short-lived oxygen radicals, a small amount of ozone and chlorine dioxide due to migration of ions from the external (anode) electrode chamber and is discharged through an 8 "nozzle as a disinfectant solution. Example 4

To process drinking water, water is supplied through the pipe T from the water supply pipe, which enters the external cathode chamber, then the water exits the pipe 7 "and through the pipe 8 'enters the internal electrode chamber. Water entering the internal (anode) electrode chamber under the influence of oxidation the reduction processes occurring in both chambers are disinfected, changes the redox potential and is discharged through the 8 "pipe in the form of clean drinking water.

The examples given do not exhaust the scope of the claimed device, since, depending on the solutions used and the polarity of the electrodes, anolyte and catholyte with other desired properties can be obtained. The device can also be used for disinfecting water, changing the redox potential of water, cathodic softening of water and other purposes.

A device made according to the invention has been tested by known methods. The table shows the performance of his work. Table

As can be seen from the drawing and the above description, the device has axial nozzles for supplying / discharging the processed fluid, which allows it to be connected directly to the line without the use of additional adapters - elbow bends. The same axial nozzles are simultaneously fasteners, since as 0 bolts are screwed into the end holes of the internal electrodes, clamping the electrodes between the end caps. The covers are made identical at both ends. Each can be made by the national team and consist of two parts - one part facing outward and the second part - inner sleeve. Unlike the prototype, the channels for supplying / discharging the processed fluid are made not in the internal electrode, but in the dielectric sleeve 11 (or in the lid itself, if it is not prefabricated). This increases the overhaul periods for replacing the internal electrode, as it remains solid and

- a special coating protected from electro-corrosion, if it is made of metal,

- has no embrittling holes in it if their graphite is made. With this design and when the channels are run at an angle to the axis of the device, stagnation zones and turbulent turbulence at the input / output of the inner chamber

Claims

CLAIM 1. A device for the electrochemical treatment of water or aqueous solutions, comprising end caps, an outer tube electrode, inside of which an inner electrode is coaxially located, the annular cavity between them is divided by a coaxial semipermeable diaphragm into an inner chamber and an outer chamber, each of which is provided with an input and outlet pipe, while the input and output pipe of the inner chamber are made axial, connected to the inner electrode by means of a threaded connection and fix f end caps, characterized in that the side walls of the axial nozzle openings communicating with the internal chamber through the channels formed in the end covers, and oriented in radial planes. 2. The device according to p. 1, characterized in that the inner electrode is made of a rod, has a blind threaded hole at each end to form a screw pair with an axial pipe provided with a threaded section on the outer surface 3. The device according to p. 1, characterized in that the end caps are prefabricated, consisting of two parts, while the channels are made in those parts of the cover that are facing inward. 4. The device according to p. 2, characterized in that the end caps are prefabricated, consisting of two parts, while the channels are made in those parts of the cover that are facing inward. 5. The device according to any one of paragraphs. 1 to 4, characterized in that the channels in the end caps are oriented at an angle to the axis of the device.