EP1470299B1 - Method and system for drying a wall - Google Patents

Abstract

The invention relates to a method for drying a wall, especially brickwork (2). According to the inventive method, at least two wall electrodes (7, 8, 9) are installed in the wall (2) vertically spaced apart from one another, and at least one floor electrode (13, 14) is installed in a floor area (4) below said wall (2). A direct voltage is applied between the wall electrodes (7, 8, 9) and the floor electrode (13, 14) in such a manner that the wall electrodes (7, 8, 9) are linked with a negative pole (28) of a direct voltage source (1) and the floor electrode (13, 14) is linked with a positive pole (25, 26) of the direct voltage source, and reverse polarity pulse voltage is temporally superimposed on the direct voltage.

Description

The invention relates to a method and an arrangement for dehumidifying a wall, in particular a masonry of buildings.

For dehumidifying masonry methods are known in which suitable electric fields or electromagnetic radiation generated and directed to the masonry. These methods exploit the fact that electrical or electromagnetic fields have an effect on the moisture in the masonry and can be used for dehumidifying the masonry when suitably used. For this purpose, in particular electroosmotic methods are known in which an electric field is applied between mounted in the masonry masonry electrodes and embedded in the ground or in the ground area bottom electrodes. The electric field causes ions dissolved in the moisture to be drawn to the respective electrodes, the water molecules following the concentration gradient of the ions and thus being able to accumulate in the area of the bottom electrodes.

However, a disadvantage of conventional electro-osmosis processes is that, as a rule, residual moisture in the masonry, in particular in a lower base region, can not be removed. Extensive dehumidification of masonry is very time consuming, usually a high number of electrodes in the walls and the floor area must be provided, which leads to some significant structural interference in the masonry. Furthermore, the concentration accumulations of ions usually to efflorescence in the brickwork, which leads to aesthetic and qualitative impairments.

To avoid such disadvantages, therefore, some methods are used in which an electromagnetic radiation is irradiated without direct galvanic coupling to the masonry. The EP 0 395 085 B1 shows such a method, in which the electromagnetic radiation generated by an electromagnetic resonator and emitted by an emitting device is directed onto the masonry, wherein the resonator for generating the electromagnetic radiation is excited with periodic electrical pulses of a pulse train frequency which is smaller than the natural vibration Frequency of the resonator is. The frequency of the radiated electromagnetic radiation is in the range around 150 kHz. However, such a method requires a relatively high expenditure on equipment for generating the electromagnetic radiation, usually allows only relatively low power and can lead to electrical conductors in masonry - especially electrical cables, steel reinforcements and pipes - to induce unwanted and possibly harmful currents; Furthermore, in some such procedures a radio interference suppression must be ensured.

The US 6,117,295 shows a method and an arrangement for dehumidifying a porous material using electroosmosis. Here, among other things, electrodes are mounted in the walls and in the floor of a building and connected together to the positive pole of a DC voltage source. Furthermore, an electrode is laid in the ground outside the building and connected to the negative pole of the DC voltage source. A voltage pattern is input in which the DC voltage or positive DC voltage pulses of alternating magnitude negative voltage pulses and neutral voltage pulses is alternately interrupted.

The invention has for its object to provide a method and an arrangement for dehumidifying a wall, in particular masonry, which ensure a relatively fast and high dehumidification of the wall with relatively little effort. Here, advantageously, a cost-effective application in a small portion of the wall already allow a quick and safe dehumidification.

This object is achieved by a method according to claim 1 and an arrangement according to claim 11. The subclaims describe preferred developments.

The wall may in particular a masonry of a building, for. B. masonry, concrete or similar material. Furthermore, the wall can in principle also be made of z. Wood or a wood product. The wall may include both vertical wall areas as well as ceiling and floor areas.

According to the invention, a DC voltage is thus superimposed with a temporarily applied pulse voltage. Due to the DC voltage, according to the known principle of electroosmosis, a spatial concentration of the ions dissolved in the moisture, which entrain the moisture, is made possible. By reversely poled pulse voltage according to the invention a depletion of enriched with ions or conductive minerals and acids water molecules is temporarily achieved, which largely prevents the disadvantages of conventional electro-osmosis process described above. The moisture transport due to the ion concentration is not affected by the short-term voltage pulses, so that a fast and safe dehumidification is possible.

Since only momentarily a pulse voltage is applied to the electrodes, but not permanently applied an AC voltage, do not create permanent electromagnetic fields that affect metallic objects in the wall or the environment of the wall. Thus, no additional corrosion of such metal parts is caused. Furthermore, can be prevented by the smooth movement of the water with the short-term depletion of ions excessive, superficial efflorescence in the masonry or at least kept low

By superimposing the DC voltage with the pulse voltage, an influencing of the flow potential or zeta potential in favor of the dehumidification process is achieved. In a particularly preferred manner, at least in the bottom region or the earth, ie generally below the lower edge of the cellar or the floor slab of a building, at least two bottom electrodes are provided, which are connected in alternation with the pole of the voltage source, which can be achieved for example via a suitable relay in a control device. In this case, the alternating connection can be effected both with the total voltage composed of DC voltage and pulse voltage, and only with the DC voltage or the pulse voltage. The alternate connection allows a more even accumulation of moisture in a larger section of the floor area. The bottom electrodes may in particular have different lengths and / or be inserted or attached to different depths.

The electrodes may advantageously be designed as rods or rods insulated in a shaft region, the electrode end of which is exposed within the masonry or the bottom region. As a result, a uniform formation of the electric field within the masonry and the bottom area is achieved, so that the formation of currents along the surface, which leads to a lower moisture removal in the masonry and to a greater blooming on the surface, is kept low. However, in principle, it is also possible to introduce at least some of the electrodes as uninsulated rods or rods in order, for example, to temporarily remove moisture from a surface area at higher intervals. The electrodes can z. As a metal such as aluminum or stainless steel or advantageously a conductive plastic, for. As a plastic material with Graphiteinlagerungen be prepared to prevent corrosion and self-consumption of the electrodes.

The wall electrodes are advantageously arranged vertically one above the other in a line, whereby a rapid dehumidification in the vertical direction is made possible. Here, for example, a wall electrode with a negative pole connection can be arranged vertically below the vertical wall region, whereby the vertical transport of moisture from the masonry can be improved.

• Figur 1 einen Querschnitt durch ein Mauerwerk einer ersten Ausführungsform mit einer erfindungsgemäßen Anordnung;
• Figur 2 einen Querschnitt durch ein Mauerwerk einer weiteren Ausführungsform mit einer erfindungsgemäßen Anordnung;
• Figur 3 ein Blockschaltbild einer Ausführungsform einer erfindungsgemäßen Steuereinrichtung.

The invention will be explained in more detail below with reference to the accompanying drawings of an embodiment. Show it:

• Figure 1 shows a cross section through a masonry of a first embodiment with an inventive arrangement;
• Figure 2 shows a cross section through a masonry of another embodiment with an inventive arrangement;
• 3 shows a block diagram of an embodiment of a control device according to the invention.

A control device 1 is mounted on a masonry 2, which is formed above a bottom portion 4 or Erdbereich. The floor area 4 is bounded above by a lower edge 5 of the building, for example the lower edge of the basement or a floor slab. In the masonry moisture is contained, in particular moisture due to a new building, a repainting or by rising groundwater, backwater or leachate.

In the masonry 2 holes are formed in a vertical line one above the other, extending from the surface of the masonry in the horizontal direction and vertical to the surface. In the holes serving as wall electrodes according to the invention, 15 cm long masonry electrodes 7, 8 and 9 are introduced. Each masonry electrode is made of a conductive material, for example a metal such as aluminum or stainless steel or advantageously a conductive plastic, and surrounded in a shank region with an insulation 16, for example a shrink tube, so that only one electrode end 18 is exposed in the masonry 2. Another masonry electrode 12 constructed in the same way is inserted vertically below the other masonry electrodes 7, 8, 9 at the lower end of the masonry 2 at an oblique angle into the base region 4.

In the bottom area 4 below and laterally next to the masonry 2 are vertically from above bottom electrodes 13, 14 at different distances introduced to the masonry 2. The two bottom electrodes 13, 14 are constructed according to the masonry electrodes 7, 8, 9, 12 described above and have a different length or shaft length, so that their electrode ends 18 are exposed at different depths below the lower edge 5.

The masonry electrodes 7, 8, 9, 12 are connected via lines 20 to a negative pole 28 and a cathode of a DC voltage source of 20 volts of the control device 1. The bottom electrodes 13, 14 are connected via separate lines 21, each having a positive pole 25 and 26 of the DC voltage source of the control device 1, wherein alternatively the pole 25 or the pole 26 can be connected via a relay 23 to an anode of the DC voltage source of the control device 1. Further, in the control device 1, a pulse voltage source is connected in parallel to the DC voltage source, which is reversed polarity with respect to the DC voltage source and thus the DC voltage source with inverse pulses with peak voltages of 1.5 to 3 V and Generated current pulses with a pulse duration of 0.2 to 2 s at a duty cycle DUTY of, for example, 25% to 80%. Thus, in each case a total voltage is applied between each of a bottom electrode 13, 14 and the masonry electrodes 7, 8, 9, 12 connected in parallel, resulting in a superimposition of the DC voltage and the reverse polarity of the pulse voltage.

The control of the switching of the relay 23 and the pulse voltage source can be done on the one hand according to a predetermined program of the control device 1. This can be done for example after measuring an initial moisture content of the masonry and depending on the size of the masonry or the total moisture contained in the masonry 2.

The controller 1 can be operated with standard mains voltage of 220 to 230 volts AC. A maximum output current of approx. 300 mA can be selected.

In the further embodiment shown in Figure 2, in addition to the first embodiment in the masonry 2, a plurality of moisture sensors 29 are provided at different positions of the masonry 2, which measure the moisture of the masonry 2 at their respective positions and moisture signals S1 via lines 30 to the control device first transfer; In principle, only one sensor 29 can be provided. The control of the level of the DC voltage and / or the relay 23 and / or the pulse voltage source takes place as a function of the output from the sensors 29 moisture signals. The control device 1 compares the humidity signals S1 with predetermined values and decides whether to stop a drying process. In this case, the inventive method can be completely stopped or advantageously a part of the electrodes, for. B. the bottom electrode 14 and optionally one or more wall electrodes are connected as a limiting electrode with a relation to the drying mode lower limiting current to maintain the dried state.

The structure of the control device 1 can in the embodiment of Fig. 2 z. B. according to FIG. 3. Here, the moisture signals S1 are received by an interface 32 and moisture signals S2 to a computing device 37 -. As a microprocessor or microcomputer - issued. Alternatively, the humidity signals S1 can also be output directly to the calculation device 37. The calculation device 37 furthermore receives a time signal S5 from a clock 38 and a memory signal S4 from a data memory 40; the calculation device 37 preferably also stores memory signals S4 in this memory. A power converter 36 receives an AC current through input terminals 33 from an external power supply and outputs the above-mentioned DC and pulse voltage. The calculation device 37 continues to exist Switching signals S6 to a relay 34 for selectively outputting the voltages to the positive poles 25, 26 and preferably also a current control signal to the current transformer 36 for setting the drying mode with higher current or a limiting mode with a lower limiting current to keep dry an already dried wall, possibly also for switching off the current transformer 36.

Claims (24)

1. Method for dehumidifying a wall, in particular masonry (2), in which
   at least two wall electrodes (7, 8, 9) are mounted in a vertically spaced manner in the wall (2),
   at least one further electrode (13, 14) is mounted outside of the wall (2), and
   a d.c. voltage is applied between the wall electrodes (7, 8, 9) and the further electrode (13, 14),
   wherein a transient pulse voltage of opposite polarity is intermittently superimposed on the d.c. voltage,
   characterised in that
   the further electrode is a ground electrode (13, 14) which is mounted in a ground area (4) disposed below the wall (2),
   the d.c. voltage is applied to the wall electrodes and the at least one ground electrode such that the wall electrodes (7, 8, 9) are connected to a negative pole (28) of a d.c. voltage source (1) and the ground electrode (13, 14) is connected, to a positive pole (25, 26) of the d.c. voltage source, and
   a peak voltage of the pulse voltage is of a lower value than the d.c. voltage.
2. Method according to Claim 1, characterised in that the wall electrodes (7, 8, 9) are disposed in a vertical line one above the other in the wall (2).
3. Method according to either of the preceding Claims, characterised in that a wall electrode (12) connected to the negative pole (28) of the d.c. voltage source (1) is disposed in the ground area (4) vertically below the wall electrodes (7, 8, 9) provided in the wall (2).
4. Method according to any one of the preceding Claims, characterised in that at least two ground electrodes (13, 14) are disposed in the ground area (4), preferably at different depths, and the d.c. voltage and/or the pulse voltage are/is alternately applied to one of the ground electrodes (13, 14).
5. Method according to any one of the preceding Claims, characterised in that the d.c. voltage lies in the range from 10 to 30 volts, preferably at approximately 20 volts.
6. Method according to any one of the preceding Claims, characterised in that a peak voltage of the pulse voltage lies in the range from 0.5 to 10 volts, preferably from 1.5 to 3 volts.
7. Method according to any one of the preceding Claims, characterised in that the pulse duration of the voltage pulses lies between 0.1 and 4 s, preferably 0.2 and 2 s.
8. Method according to any one of the preceding Claims, characterised in that a current which flows between the electrodes is limited to a current intensity range between 100 and 500 mA, preferably approximately 300 mA.
9. Method according to any one of the preceding Claims, characterised in that a duty factor of the pulsed current lies between 20 and 90%, preferably between 25 and 80%.
10. Method according to any one of the preceding Claims, characterised in that a degree of moisture of the wall (2) is measured at least at one location, preferably a plurality of locations, and the d.c. voltage and/or pulse voltage are/is adjusted in accordance with the measured degree of moisture.
11. Arrangement for dehumidifying a wall (2), with
    at least two wall electrodes (7, 8, 9) disposed in a spaced manner in the vertical direction in the wall (2),
    at least one further electrode,
    a control device (1) with a d.c. voltage source and a pulse voltage source,
    the wall electrodes (7, 8, 9) and the at least one further electrode (13, 14) are connected to the different poles (25, 26) of the d.c. voltage source, and a transient pulse voltage generated by the pulse voltage source is intermittently superimposed on the d.c. voltage of the d.c. voltage source, wherein the pulse voltage is of opposite polarity to the d.c. voltage,
    characterised in that
    the at least one further electrode is a ground electrode (13, 14) which is mounted in a ground area (4) below the wall (2),
    the wall electrodes (7, 8, 9) are connected to a negative pole (28) and the at least one ground electrode (13, 14) is connected to a positive pole (25, 26) of the d.c. voltage source, and
    a peak voltage of the pulse voltage is of a lower value than the d.c. voltage.
12. Arrangement according to Claim 11, characterised in that the wall electrodes (7, 8, 9) are disposed in a vertical line one above the other in the wall (2).
13. Arrangement according to Claim 11 or 12, characterised in that a wall electrode (12) connected to the negative pole (28) of the d.c. voltage source (1) is disposed in the ground area (4) vertically below the wall electrodes (7, 8, 9) provided in the wall (2).
14. Arrangement according to any one of Claims 11 to 13, characterised in that the at least one ground
    electrode (13, 14) is disposed below a lower edge (5) of a foundation slab or a cellar of the wall.
15. Arrangement according to any one of Claims 11 to 14, characterised in that at least two ground electrodes (13, 14) are disposed in the ground area (4), preferably at different depths, and are alternately connected to the d.c. voltage source and/or the pulse voltage source.
16. Arrangement according to any one of Claims 11 to 15, characterised in that the wall electrodes (7, 8, 9, 12) and/or ground electrodes (13, 14) are formed in the shape of rods and, in an outer portion extending from the edge
    of the wall (2) or of the ground area (4), comprise insulation (16), preferably a shrink-on tube, which leaves free an electrode end (18) inside the wall (2) or the ground area (4).
17. Arrangement according to any one of Claims 11 to 16, characterised in that the d.c. voltage is 10 to 30 volts, preferably approximately 20 volts.
18. Arrangement according to any one of Claims 11 to 17, characterised in that a current which flows between the electrodes is limited to a current intensity range between 100 and 500 mA, preferably approximately 300 mA.
19. Arrangement according to any one of Claims 11 to 18, characterised in that the peak voltage of the pulse lies between 0.5 and 10 volts, preferably 1.5 and 3 volts.
20. Arrangement according to any one of Claims 11 to 19, characterised in that a duty factor of the pulsed current lies between 20 and 90%, preferably between 25 and 80%.
21. Arrangement according to any one of Claims 11 to 20, characterised in that the pulse duration of the pulse voltage lies between 0.1 and 4 s, preferably 0.2 and 2 s.
22. Arrangement according to any one of Claims 11 to 21, characterised in that sensors are provided for measuring the wall (2), which sensors deliver at least one measuring signal to the control device (1), and the control device applies the d.c. voltage and/or pulse voltage in accordance with the measuring signal.
23. Arrangement according to any one of Claims 11 to 22, characterised in that at least one, preferably a plurality of moisture sensor(s) (29) is/are provided in the wall (2), which sensors in each case output a moisture signal (81) to the control device (1).
24. Arrangement according to Claim 23, characterised in that the control device (1) comprises a current transformer (36) for outputting the d.c. voltage and the pulse voltage, a relay (34) for connecting one or a plurality of positive pole(s) (25, 26) to the current transformer (36), a calculation device (37) for establishing a degree of moisture from the moisture signals and comparison with predetermined values and for controlling the relay (34) and preferably the current transformer (36), and a memory (40) for storing adjustment data and outputting adjustment signals (S4) to the calculation device (37).

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