WO2003062546A1

WO2003062546A1 - Method and system for drying a wall

Info

Publication number: WO2003062546A1
Application number: PCT/DE2003/000207
Authority: WO
Inventors: Manfred Arnold; Martin Fischer
Original assignee: Manfred Arnold; Martin Fischer
Priority date: 2002-01-25
Filing date: 2003-01-27
Publication date: 2003-07-31
Also published as: EP1470299B1; DE10202764A1; DE50307810D1; ATE368777T1; EP1470299A1

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

Method and arrangement for dehumidifying a wall

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

Methods are known for dehumidifying masonry in which suitable electric fields or electromagnetic radiation are generated and directed onto the masonry. These methods take advantage of the fact that electrical or electromagnetic fields have an influence on the moisture in the masonry and can be used to dehumidify the masonry if used appropriately. For this purpose, electroosmotic methods are known in particular, in which an electric field is applied between masonry electrodes installed in the masonry and floor electrodes embedded in the earth or in the floor area. Ions dissolved in the moisture are drawn to the respective electrodes by the electric field, the water molecules following the concentration gradient of the ions and thus being able to be accumulated in the area of the bottom electrodes.

A disadvantage of conventional electro-osmosis processes, however, is that, as a rule, residual moisture in the masonry, in particular in a lower base area, cannot be removed. Extensive dehumidification of the masonry is very time-consuming, as a rule a large number of electrodes must be provided in the walls and the floor area, which in some cases leads to considerable structural interventions in the masonry. Furthermore, the concentration accumulations of lo- usually lead to efflorescence in the masonry, which leads to aesthetic and qualitative impairments.

In order to avoid such disadvantages, methods are sometimes used in which electromagnetic radiation is radiated onto the masonry without direct galvanic coupling. EP 0 395 085 B1 shows a method of this type in which electromagnetic radiation generated by an electromagnetic resonator and emitted by a radiation device is directed onto the masonry, the resonator being excited to generate the electromagnetic radiation with periodic electrical pulses of a pulse train frequency, which is less than the natural oscillation frequency of the resonator. The frequency of the emitted electromagnetic radiation is in the range around 150 kHz. However, such a method requires a relatively high outlay in terms of equipment for generating the electromagnetic radiation, generally only enables relatively low powers and can lead to the induction of unwanted and possibly harmful currents in the case of electrical conductors in masonry, in particular electrical lines, steel reinforcements and pipes ; furthermore, in some cases such processes interference suppression can be guaranteed.

The invention has for its object to provide a method and an arrangement for dehumidifying a wall, in particular masonry, which ensure a relatively quick and high dehumidification of the wall with relatively little effort. In this case, an inexpensive application in a small part of the wall should advantageously enable rapid and safe dehumidification.

This object is achieved by a method according to claim 1 and an arrangement according to claim 13. The subclaims describe preferred further developments. The wall can in particular be a masonry of a building, e.g. B. from masonry, concrete or similar material. Furthermore, the wall can in principle also from z. B. wood or a wood product. The wall can include vertical wall areas as well as ceiling and floor areas.

According to the invention, a DC voltage is therefore superimposed with an at least temporarily applied pulse voltage. The direct voltage enables a spatial concentration of the ions dissolved in the moisture, which draw the moisture with them, in accordance with the principle of electroosmosis known per se. Due to the reverse polarity of the pulse voltage, a depletion of the water molecules enriched with ions or conductive minerals and acids is achieved according to the invention, which largely prevents the above-described disadvantages of conventional electroosmosis processes. The moisture transport due to the ion concentration is not impaired by the brief voltage impulses, so that a quick and safe dehumidification is possible.

Since a pulse voltage is only temporarily input to the electrodes, but an AC voltage is not permanently applied, there are no permanent electromagnetic fields that affect metallic objects in the wall or in the vicinity of the wall. Thus, no additional corrosion of such metal parts is caused. Furthermore, the uniform movement of the water with the short-term depletion of ions can prevent or at least minimize excessive surface efflorescence in the masonry.

By superimposing the DC voltage on the impulse voltage, the flow potential or zeta potential is influenced in favor of the dehumidification process. In a particularly preferred manner, at least in the floor area or the ground - ie generally below the lower edge of the basement or the floor slab of a building two bottom electrodes are provided, which are alternately connected to the pole of the voltage source, which can be achieved, for example, by means of a suitable relay in a control device. In this case, the alternating connection can be made both with the total voltage composed of DC voltage and pulse voltage and only with the DC voltage or the pulse voltage. The alternating connection enables a more even accumulation of moisture in a larger section of the floor area. The bottom electrodes can in particular have different lengths and / or can be inserted or attached at different depths.

The electrodes can advantageously be designed as rods or rods insulated in a shaft area, the electrode ends of which are exposed within the masonry or the floor area. This achieves a uniform formation of the electric field within the masonry and the floor area, so that the formation of currents along the surface, which leads to less moisture removal in the masonry and to a greater blooming on the surface, is kept low. However, it is fundamentally also possible to introduce at least some of the electrodes as uninsulated rods or rods, for example in order to temporarily remove more moisture from a surface area, for example. The electrodes can e.g. B. a metal such as aluminum or stainless steel or advantageously a conductive plastic, e.g. B. a plastic material with graphite inclusions, to avoid corrosion and self-consumption of the electrodes.

The wall electrodes are advantageously arranged vertically one above the other in a line, which enables rapid removal of moisture in the vertical direction. Here, for example, a wall electrode with a negative pole connection can also be arranged vertically below the vertical wall area, as a result of which the vertical transport of moisture from the masonry can be improved. The invention is explained below with reference to the accompanying drawing of an embodiment. Show it:

1 shows a cross section through a masonry of a first embodiment with an arrangement according to the invention;

Figure 2 shows a cross section through a masonry of a further embodiment with an arrangement according to the invention;

Figure 3 is a block diagram of an embodiment of a control device according to the invention.

A control device 1 is attached to a masonry 2, which is formed above a floor area 4 or earth area. The floor area 4 is delimited at the top by a lower edge 5 of the building, for example the lower edge of the basement or a floor slab. Moisture is contained in the masonry, in particular moisture due to a new building, new plastering or also due to rising groundwater, backwater or leachate.

In the masonry 2, holes are formed in a vertical line one above the other, which extend from the surface of the masonry in a horizontal direction and vertically to the surface. Serving as wall electrodes according to the invention, 15 cm long masonry electrodes 7, 8 and 9 are introduced into the holes. 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 is surrounded in a shaft area with 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 under the other masonry electrodes 7, 8, 9 at the lower end of the masonry 2 at an oblique angle into the floor area 4.

In the bottom area 4 below and to the side of the masonry 2 are bottom electrodes 13, 14 vertically from above at different distances brought to masonry 2. The two bottom electrodes 13, 14 are constructed in accordance with the masonry electrodes 7, 8, 9, 12 described above and have a different length or different shaft length, so that their electrode ends 18 are exposed to a different depth under the lower edge 5.

The masonry electrodes 7, 8, 9, 12 are connected via lines 20 to a negative pole 28 or 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 to a positive pole 25 and 26 of the DC voltage source of the control device 1, 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. The switching of the relay 23 is carried out by appropriate programming of the control device 1. Furthermore, a pulse voltage source is connected in parallel to the DC voltage source in the control device 1, which is polarized in reverse to the DC voltage source and thus the DC voltage source with inverse pulses with peak voltages of 1.5 to 3 V and Current pulses with a pulse duration of 0.2 to 2 s with a pause ratio DUTY of, for example, 25% to 80% are generated. Thus, a total voltage is applied between a bottom electrode 13, 14 and the masonry electrodes 7, 8, 9, 12 connected in parallel, which results as a superimposition of the DC voltage and the reverse-polarized pulse voltage.

The switching of the relay 23 and the pulse voltage source can be controlled on the one hand according to a predetermined program of the control device 1. This can take place, 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 control device 1 can be operated with the usual 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 FIG. 2, in addition to the first embodiment, a plurality of moisture sensors 29 are provided in the masonry 2 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 1 transfer; in principle, only one sensor 29 can also 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 moisture signals output by the sensors 29. The control device 1 compares the moisture signals S1 with predetermined values and decides whether a drying process is to be ended. In this case, the method according to the invention can be terminated completely or advantageously a part of the electrodes, e.g. B. the bottom electrode 14 and possibly one or more wall electrodes can be switched as a limiting electrode with a lower limiting current compared to the drying mode, in order to keep the dried state.

The structure of the control device 1 in the embodiment of FIG. 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 - e.g. B. a microprocessor or microcomputer - output. Alternatively, the moisture signals S1 can also be output directly to the calculation device 37. The calculation device 37 also receives a time signal S5 from a clock 38 and a memory signal S4 from a data memory 40, preferably the calculation device 37 also stores memory signals S4 therein. A current converter 36 receives an alternating current AC from an external power supply via input connections 33 and outputs the above-mentioned direct and pulse voltage. The calculation device 37 also outputs then switching signals S6 to a relay 34 for optionally 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 a higher current or a limiting mode with a lower limiting current to keep an already dried wall dry, if necessary also for switching off the current transformer 36.

Claims

Patent claims

1. Method for dehumidifying a wall, in particular a masonry (2), in which at least two wall electrodes (7, 8, 9) are vertically spaced in the

Wall (2) are attached, at least one bottom electrode (13, 14) is attached in a bottom area (4) arranged below the wall (2), and between the wall electrodes (7, 8, 9) and the bottom electrode (13, 14) a direct voltage is applied such that the wall electrodes (7, 8, 9) are connected to a negative pole (28) of a direct voltage source (1) and the bottom electrode (13, 14) is connected to a positive pole (25, 26) of the direct voltage source is, the DC voltage is sometimes superimposed on a reverse-polarized pulse voltage.

2. The method according to claim 1, characterized in that a peak voltage of the pulse voltage has a smaller amount than the DC voltage.

3. The method according to claim 1 or 2, characterized in that the wall electrodes (7, 8, 9) are arranged in a vertical line one above the other in the wall (2).

4. The method according to any one of the preceding claims, characterized in that a wall electrode (12) connected to the negative pole (28) of the direct voltage source (1) in the bottom region (4) vertically below the wall electrodes (7) provided in the wall (2). 8, 9) is arranged.

Method according to one of the preceding claims, characterized in that at least two bottom electrodes (13, 14)), preferably at different depths, are arranged in the bottom region (4) and the DC voltage and / or the pulse voltage are alternately applied to one of the bottom electrodes (13, 14).

6. The method according to any one of the preceding claims, characterized in that the DC voltage is in the range of 10 to 30 volts, preferably about 20 volts.

7. The method according to any one of the preceding claims, characterized in that a peak voltage of the pulse voltage is in the range from 0.5 to 10 volts, preferably from 1.5 to 3 volts.

8. The method according to any one of the preceding claims, characterized in that the pulse duration of the voltage pulses is between 0.1 and 4 s, preferably 0.2 and 2 s.

9. The method according to any one of the preceding claims, characterized in that a current flowing between the electrodes is limited to a current range between 100 and 500 mA, preferably about 300 mA.

10. The method according to any one of the preceding claims, characterized in that a pause ratio of the pulse current is between 20 and 90%, preferably between 25 and 80%.

11. The method according to any one of the preceding claims, characterized in that a degree of moisture in the wall (2) is measured at at least one point, preferably several points, and the DC voltage and / or pulse voltage is set as a function of the measured degree of moisture.

12. The method according to any one of the preceding claims, characterized in that the at least one bottom electrode (13, 14) is arranged below the wall electrodes (7, 8, 9).

13. Arrangement for dehumidifying a wall (2), with a control device (1) with a DC voltage source and a pulse voltage voltage source, at least two wall electrodes (7, 8, 9) arranged at a distance from each other in the vertical direction, at least one in a bottom region (4) below the wall (2), bottom electrode (13, 14), the wall electrodes (7, 8, 9) with a negative pole (28) and the at least one bottom electrode (13, 14) with a positive pole

(25, 26) of the DC voltage source, and a pulse voltage generated by the pulse voltage source is temporarily superimposed on the DC voltage of the DC voltage source, the pulse voltage having an inverse polarity with respect to the DC voltage.

14. Arrangement according to claim 13, characterized in that a peak voltage of the pulse voltage has a smaller amount than the DC voltage.

15. Arrangement according to claim 13 or 14, characterized in that the wall electrodes (7, 8, 9) are arranged in a vertical line one above the other in the wall (2).

16. Arrangement according to one of claims 13 to 15, characterized in that a wall electrode (12) connected to the negative pole (28) of the DC voltage source (1) in the bottom region (4) vertically below the wall electrodes (2) provided in the wall (2). 7, 8, 9) is arranged.

17. Arrangement according to one of claims 13 to 16, characterized in that the at least one bottom electrode (13, 14) below a lower edge (5) of a base plate or a basement of the wall is arranged.

18. Arrangement according to one of claims 13 to 17, characterized in that in the bottom region (4) at least two bottom electrodes

(13, 14), preferably at different depths, and are alternately connected to the DC voltage source and / or the pulse voltage source.

19. Arrangement according to one of claims 13 to 18, characterized in that the wall electrodes (7, 8, 9, 12) and / or bottom electrodes (13, 14) are rod-shaped and in an outer, from the edge of the wall ( 2) or the bottom region (4) from the extending section, an insulation (16), preferably a shrink tube, which leaves an electrode end (18) inside the wall (2) or the bottom region (4).

20. Arrangement according to one of claims 13 to 19, characterized in that the DC voltage is 10 to 30 volts, preferably about 20 volts.

21. Arrangement according to one of claims 13 to 20, characterized in that a current flowing between the electrodes is limited to a current range between 100 and 500 mA, preferably about 300 mA.

22. Arrangement according to one of claims 13 to 21, characterized in that the peak voltage of the pulse is between 0.5 and 10 volts, preferably 1, 5 and 3 volts.

23. Arrangement according to one of claims 13 to 22, characterized in that a pause ratio of the pulse current is between 20 and 90%, preferably between 25 and 80%.

24. Arrangement according to one of claims 13 to 23, characterized in that the pulse duration of the pulse voltage is between 0.1 and 4 s, preferably 0.2 and 2 s.

25. Arrangement according to one of claims 13 to 24, characterized in that sensors for measuring the wall (2) are provided, which emit at least one measurement signal to the control device (1), and the control device in the DC voltage and / or pulse voltage Depends on the measurement signal.

26. Arrangement according to one of claims 13 to 25, characterized in that the at least one bottom electrode (13, 14) is arranged below the wall electrodes (7, 8, 9).

26. Arrangement according to one of claims 13 to 26, characterized in that in the wall (2) at least one, preferably a plurality of moisture sensors (29) are provided, each of which outputs a moisture signal (S1) to the control device (1).

26. The arrangement according to claim 26, characterized in that the control device (1) has a current transformer (36) for outputting the DC voltage and the pulse voltage, a relay (34) for connecting one or more positive poles (25, 26) to the current - Converter (36), a calculation device (37) for determining a

Degree of humidity 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 setting data and outputting setting signals (S4) to the calculation device (37) ,