Patent ID: 6126802
Filing Date: 2000-10-03
Classification: E04B

Abstract:
A method for regulating and optimizing transport of liquid in a porous structure by means of electroosmosis, wherein there are employed one or more electrode pairs, wherein each electrode pair constitutes an electrical circuit comprising an anode in the porous structure and a cathode in earth, wherein the anode and the cathode are connected to respective outputs on a power source which supplies a pulse voltage to the electrode pair in the form of a sequence of pulse patterns, and wherein each pulse pattern comprises a first positive pulse with a given amplitude V.sub.s and a duration t.sub.2, a negative pulse with the same amplitude V.sub.5, but substantially shorter duration t.sub.1 than the positive pulse, and subsequently a neutral pulse whose duration t.sub.3 is initially much less than the duration of the negative pulse and constitutes only a small fraction of the pulse pattern's duration T.sub.p,characterized by detecting any potential difference .increment.V.sub.p over the anode and the cathode in at least one electrode pair during the duration t.sub.3 of the neutral pulse in the pulse pattern which falls in the first measuring cycle, and, if ##EQU3## depending on the ratio ##EQU4## regulating a) the duration t.sub.3 of the neutral pulse, orb) the duration of pulse T.sub.p of the pulse pattern, orc) both the duration t.sub.3 of the neutral pulse and the duration T.sub.p of the pulse pattern,whereupon the measuring cycle is repeated with a predetermined repetition frequency, since the duration t.sub.3 of the neutral pulse or the duration T.sub.p of the pulse pattern or both increase if the detected potential difference .increment.V.sub.p increases from one measuring cycle to another, and is otherwise kept constant, with the result that the duration t.sub.3 of the neutral pulse at a maximum will amount to approximately twice the initial duration t.sub.2 of the negative pulse, and the duration T.sub.p of the pulse pattern at the most 5-10 times the initial duration T.sub.p of the pulse pattern, whereupon these final values for the duration t.sub.3 of the neutral pulse and the duration T.sub.p of the pulse pattern are used in a maintenance phase after the liquid transport has ceased.