CZ278843B6 - Apparatus for separating substances from a solution by migration of ions - Google Patents

Abstract

This device is created based on the vessel (1), in the internal space of which are minimum two electrodes (2) located, and between them, there are built ionic selective and waterproof membranes (3). In the vessel, there are located two couples of membranes (3) at least, with an opposite ionic affinity and each of them is creating one work unit (4) which consists of the middle separating space (41) and the marginal scavenging spaces (42), where the separating spaces (41) closed to the separation units (4) are connected with the connecting channels (5) in series. In the scavenging spaces (42) closed to one work unit (4), at least, there are located the sets related to the porous transversals (6)

Description

The invention relates to a device for the electromigration separation of substances from solution, both ionically dissociable organic and inorganic substances, for example for the desalination of sea water.

BACKGROUND OF THE INVENTION

Membrane electrodialisers of various designs are used for separation of ionically dissociable substances from solution, whose efficiency depends on the quality and precision of production of very thin membranes, guaranteeing their very low ohmic resistance. A disadvantage of these devices is that the very narrow space between the membranes makes it difficult to distribute the working solution over their entire area, thereby reducing the efficiency of the dissociation process and increasing losses by internal heating. Another disadvantage is the possibility of monitoring the degree of separation of substances only outside the plant. The working area of effective use of electrodialysers is at higher concentrations of substances in solution, at concentrations lower than 5g / liter they are used only rarely due to their low efficiency.

For solutions with a low concentration of dissociable substances not exceeding 0.5 g / liter, devices operating on the principle of reserve osmosis are used. The disadvantages of these devices are, on the one hand, the need for an additional device for generating pressure in the working solution required for the operation of the reserve process and, on the other hand, a large amount of waste water per unit of treated solution, for example desalinated water.

Also known is a device for the free electromigration separation of substances in solution, the base unit of which comprises a vessel made of an electrically non-conductive material and provided with a series of outlets. Two electrodes are attached between the opposing walls of the vessel, between which a set of electrically non-conductive porous baffles is placed, between which ion-selective membranes are embedded in a watertight and symmetrical manner relative to the electrodes. having a water-soluble substance of less than 300mg / liter higher than membrane electrodialysers is not suitable for use in the separation of substances over a range of concentrations. At low solubles concentrations, separation is lengthy as the baffles in the central part of the base unit slow down its process. The device is not suitable for a high concentration of substances because the baffles create resistance to the migration of ions and thus greatly increase the power consumption.

SUMMARY OF THE INVENTION

These disadvantages are largely eliminated by the invention, which is a device for the electromigration separation of substances from a solution, consisting of a vessel inside which at least two electrodes are placed, between which ion-selective membranes are waterproof. It is an object of the invention that at least two pairs of membranes of opposite ionic affinity are located in the vessel, each forming one working poison.

-1i note, which consists of a central separation space and extreme flushing spaces, where the separation spaces of the individual working units are connected in series by interconnecting channels.

Preferably, sets of porous baffles are located in the flushing spaces of the at least one working unit.

The device according to the invention can be adapted adaptively for the separation of various kinds of solutions with low and high concentration of dissociable ions, while being relatively simple in construction, easy to use and can be easily supplemented by an automation for monitoring and controlling the separation process. The resulting desired concentration of substances is then achieved without the need for recirculation of the working solution in the apparatus.

Overview of the drawings

Examples of the apparatus are schematically shown in the attached drawing, in which Fig. 1 is a device for separating a high inlet concentration solution consisting of two working units; 3 is an alternative embodiment of a four-unit device for solutions with a high inlet concentration of dissociable substances.

DETAILED DESCRIPTION OF THE INVENTION

The device according to FIG. 1 consists of a container 1, preferably in the form of a cuboid, made of an electrically non-conductive material, inside which three electrodes 2 are arranged, the values of currents and voltages inserted between them being different. Between the electrodes 2 there are watertightly embedded pairs of ion selective membranes of opposite ionic affinity, each pair forming one working unit 4 consisting of a central separation space 41 and an outer flushing spaces 42. The individual separation spaces 41 are connected in series by internal interconnecting channels 5 and the flushing spaces 42 may be connected by a channel system (not shown). In the outlet working unit 4, sets of porous baffles 6 are then placed in the flushing spaces 42 for efficient separation of the solution to very low concentrations.

The device according to FIG. 2 for the separation of a solution with a low inlet concentration of dissociable substances consists of four working units 4, which are connected in series by interconnecting channels

5. sets of porous baffles are located in the flushing spaces 42 of all four work units to slow down the process

6, wherein the negative electrode 2 is located between the third and fourth working units 4.

In an alternative embodiment of the device of FIG. 2 for separating the high inlet dissociable solution solutions shown in FIG. 3, the baffles 6 are located only in the last outlet working unit 4.

During separation, the working solution is fed into the vessel 1 from which it begins to travel under the influence of direct current

The individual ions across the working unit 4 towards the respective electrodes 2, thereby separating them. The working solution is transferred via interconnecting channels 5 to other working units 6, in which the degree of separation is evaluated by means of control and regulating sensors (not shown) and subsequently the set current and voltage values on the electrodes 2 or the flow rate of the working solution through the vessel 1 are changed. it is taken regularly for use and the flushing areas are washed with waste water.

The described embodiments are not the only possible solutions according to the invention, but the number in the series of interconnected working units 6 and the number and location of the porous baffles 6 can be varied depending on the desired volume of separation process, degree of concentration of dissociated substances in solution and desired equipment efficiency.

Industrial applicability

The device according to the invention can be used in various industries, in particular for the preparation and production of drinking water from seawater, or for reducing the content of harmful inorganic salts such as nitrogen, for the purification of drinking water, or for producing deionized water of high purity.

Claims (2)

Device for electromigration separation of substances from solution, consisting of a vessel, inside which at least two electrodes are placed, between which ion-selective membranes are watertightly installed, characterized in that at least two pairs of membranes (3) opposite are placed in the vessel (1) ionic affinities, each constituting one working unit (4), which consists of a central separation space (41) and extreme flushing spaces (42), wherein the separation spaces (41) of the working units (4) are connected in series by interconnecting channels (5). Device for electromigration separation of substances from solution according to claim 1, characterized in that sets of porous partitions (6) are located in the flushing spaces (42) of the at least one working unit (4).