Classifications

• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
  • E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
  • E04B1/62—Insulation or other protection; Elements or use of specified material therefor
  • E04B1/70—Drying or keeping dry, e.g. by air vents
  • E04B1/7007—Drying or keeping dry, e.g. by air vents by using electricity, e.g. electro-osmosis

Definitions

• the invention relates to a device for electrokinetic desalination of masonry consisting of at least one positive, salt-collecting electrode arranged on or in the masonry, which is in contact with a porous, water-containing buffer material, and at least one negative electrode, against which a DC voltage is applied, and an anode assembly for use in such a device.
• the principle of electrokinetic charge separation and migration of the ions in the electric field by applying a DC voltage is used on an industrial scale e.g. used for seawater desalination.
• the most common building-damaging salts are sulfates, chlorides and nitrates.
• the origin of the salts is varied, e.g.
• Wall salts are mostly hygroscopic and therefore absorb water from the air depending on the air humidity. This increase in volume of the salt crystals causes high hydration pressures, which in turn destroy the porous building material.
• Electrophysical drying processes based on the principle of electroosmosis in porous masonry can only work if sufficient zeta potential can develop between the pore wall and the electrolyte. Excessive concentrations of soluble salts hinder the formation of this zeta potential and drainage by electroosmosis becomes impossible. For this reason, the walls must be largely desalinated before using electroosmosis.
• the principle of salt removal from the masonry is based on the use of electrokinetic charge separation.
• the charge carriers (ions) move in an electric field to the corresponding electrodes and concentrate on or around these electrodes (negative ions, anions migrate to the anode, positive ions, cations migrate to the cathode) .
• negative ions, anions migrate to the anode, positive ions, cations migrate to the cathode
• the migration rates depend on the type of ion, its size, and on the external conditions such as pressure, temperature, solvent and concentration and are for
• Ion transport in masonry is considerably slower, but is still sufficient to desalinate masonry in an acceptable period of time.
• the known methods for electrokinetic desalination of masonry mostly use metal anodes, which are broken down corrosively and whose liquid corrosion products are removed from the masonry by a plastic channel.
• the object of the invention is to provide a device for the electrokinetic desalination of masonry during its operation the disadvantages inherent in the known desalination processes are eliminated.
• the handling and installation of such a device should be simple and inexpensive, and in particular prefabricated electrodes or electrode arrangements should also be able to be used.
• the device according to the invention is now characterized in that, apart from the connection ends, the positive electrode is completely surrounded by a layer of the buffer material and that a separator layer is applied to the buffer material layer.
• the main advantage of this design is that the electrode is optimally protected against excessive corrosion by the buffer material layer, as far as possible, and the arrangement of the separator layer also creates a barrier against the diffusion of the reaction products back into the masonry.
• the separator layer should lie against the immobilizing buffer material layer at least wherever the masonry is directly adjacent.
• the invention further relates to an anode arrangement with an electrode in contact with a buffer material for use in such a device for electrokinetic desalination of masonry, the anode arrangement being characterized in that, apart from the connection ends, the electrode is completely surrounded by a layer of the buffer material and in that there is a separator layer on the buffer material layer.
• FIG. 1 shows a schematic representation of a device according to the invention for electrokinetic desalination of masonry
• FIG. 2 shows another embodiment of the device according to the invention
• FIGS. 3 to 5 different embodiments of a device according to the invention in a desalination device show usable anode arrangement.
• FIG. 1 shows a desalination device with a plurality of anodes 2 which are laid in boreholes in the wall 1 and which are wired to one another.
• the anodes 2 are each completely surrounded by an ion-immobilizing buffer material layer except for their connection ends; this is in turn enclosed by a separator layer, which is directly adjacent to the borehole walls.
• a DC voltage is applied across a current source 3 to a cathode, in this case a dead rod 4.
• FIG. 2 shows schematically a desalination device in which flat anodes 5 are arranged on the wall 1.
• the anodes which are completely embedded in ion-immobilizing buffer material except for their terminal ends, are again wired together and connected to a current source 3, a direct voltage being applied to an earth rod 4.
• the separator layer lying against the buffer material layer is arranged only on the surface facing the wall.
• FIG. 3 shows a cartridge-shaped anode arrangement 6 which is particularly suitable for laying in drilled holes in the masonry to be desalinated.
• the core of the anode arrangement is formed by a metal, preferably copper, conductor 7, which is coated with conductive plastic 8.
• a layer 9 of a buffer material is arranged around this core, which chemically and physically binds the reaction products.
• the buffer material essentially comprises water, Ca (OH) 2 , CaCO 3 and / or CaO or mixtures thereof, an addition of a gelling agent being advantageous. This has an immobilizing effect and is moisture-retaining, so that there is no risk of the area around the anode drying out.
• the layer of the buffer material is completely enclosed by a separator layer 10 formed from a microporous membrane, which in the installed state of the anode arrangement adjoins the wall of the borehole in a borehole in the masonry.
• the anode arrangement 11 is rod-shaped. This arrangement is particularly suitable for laying in wall slots.
• the electrode 12, which in turn consists of a metal conductor encased in conductive plastic, is surrounded all the way up to its two connection ends by the buffer material layer 13, which is encased on the outside by the separator layer 14. This then adjoins the walls of the anode arrangement in a wall slot in the assembled state.
• FIG. 5 shows an anode arrangement 16 arranged flat on a wall 15.
• the electrode 17 formed from a metal conductor sheathed with conductive plastic is embedded in the buffer material layer 18 in the form of serpentine windings which extend over the entire surface of the anode arrangement.
• the separator layer 19 is arranged on the side of the buffer material layer facing the wall.
• the anodes can be designed as rod, strip or surface electrodes and consist of metal, graphite, conductive plastic or of metal conductors or graphite fiber conductors coated with such an electrode.
• the buffer material essentially comprises Water, Ca (OH) 2 , CaCO 3 and / or CaO or mixtures thereof, an addition of a gelling agent being advantageous. This has an immobilizing effect and is moisture-retaining, so that there is no risk of the area around the anode drying out.
• all commercially available, but preferably agar-agar or carboxymethyl cellulose can be used as the gelling agent.
• the separator layer immediately adjacent to the masonry when installed serves as a barrier against the diffusion of the reaction products back into the masonry.
• Such separators are known per se from battery technology. They are microporous membranes which, due to their pore distribution, allow certain ions to pass through, but prevent larger agglomerates from passing through. Ion-selective membranes are also suitable.
• These membranes consist of: PTFE, asbestos, PVC, PE, PP, plastic-bound and / or glass fiber reinforced cellulose, regenerated cellulose, cellophane or stretched plastic films.
• the applied DC voltages should be as high as possible to ensure a sufficiently fast ion transport (10 to 50V).
• stick electrodes were made of copper wires coated with conductive plastic, which were embedded in a mixture of 4% by weight carboxymethyl cellulose and 96% by weight CaCO 3 .
• These stick electrodes were inserted into the drill holes in the masonry. The holes were drilled in the evaporation zone one meter above the foundation. An iron pipe hammered into the ground served as the counter electrode.
• the system was operated with a DC voltage of 36 V.
• the cou Lombard efficiency of the anion (wall salt) conversion at the anode was between 40 and 50%, depending on the degree of salinity and

Landscapes

• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Water Supply & Treatment (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Prevention Of Electric Corrosion (AREA)
• Separation Using Semi-Permeable Membranes (AREA)
• Processing Of Solid Wastes (AREA)
• Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
• Filtration Of Liquid (AREA)
• Water Treatment By Electricity Or Magnetism (AREA)
• Nitrogen And Oxygen Or Sulfur-Condensed Heterocyclic Ring Systems (AREA)
• Treating Waste Gases (AREA)
• Fire-Extinguishing Compositions (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)
• Processing Of Stones Or Stones Resemblance Materials (AREA)
• Electrolytic Production Of Metals (AREA)
• Manufacture Of Alloys Or Alloy Compounds (AREA)
• Silicates, Zeolites, And Molecular Sieves (AREA)
• Battery Electrode And Active Subsutance (AREA)
• Insulators (AREA)
• Other Surface Treatments For Metallic Materials (AREA)
• Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=3511056

Family Applications (1)

Country Status (19)

Cited By (4)

Families Citing this family (2)

Citations (4)

• 1989
  • 1989-05-30 AT AT0130789A patent/AT394409B/de not_active IP Right Cessation
• 1990
  • 1990-05-29 CZ CS902643A patent/CZ285180B6/cs not_active IP Right Cessation
  • 1990-05-29 SK SK2643-90A patent/SK280162B6/sk unknown
  • 1990-05-30 SI SI9011062A patent/SI9011062A/sl unknown
  • 1990-05-30 WO PCT/AT1990/000051 patent/WO1990015203A1/de active IP Right Grant
  • 1990-05-30 CA CA002033167A patent/CA2033167A1/en not_active Abandoned
  • 1990-05-30 HU HU905208A patent/HU209897B/hu not_active IP Right Cessation
  • 1990-05-30 DD DD90341133A patent/DD294750A5/de not_active IP Right Cessation
  • 1990-05-30 EP EP90908410A patent/EP0427840B1/de not_active Expired - Lifetime
  • 1990-05-30 ES ES90908410T patent/ES2044595T3/es not_active Expired - Lifetime
  • 1990-05-30 DE DE9090908410T patent/DE59002386D1/de not_active Expired - Fee Related
  • 1990-05-30 UA UA4894405A patent/UA13472A/uk unknown
  • 1990-05-30 AT AT90908410T patent/ATE93291T1/de not_active IP Right Cessation
  • 1990-05-30 YU YU106290A patent/YU106290A/sh unknown
  • 1990-05-30 PL PL90285402A patent/PL163847B1/pl unknown
  • 1990-05-30 DK DK90908410.5T patent/DK0427840T3/da active
• 1991
  • 1991-01-29 RU SU914894405A patent/RU1834960C/ru active
• 1992
  • 1992-11-11 HR HRP-1062/90A patent/HRP921231B1/xx not_active IP Right Cessation
• 1993
  • 1993-04-08 LV LV930235A patent/LV5314A3/xx unknown
  • 1993-05-06 LT LTIP513A patent/LT3290B/lt not_active IP Right Cessation

Patent Citations (4)

Non-Patent Citations (2)

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