FAQ - pro aqua Diamantelektroden Produktion GmbH

Because every water drop counts.

How are BDD Cells to be operated?

BDD Cells are to be operated with DC voltage. The current-voltage requirement depends on the size of the cell and the conductivity of the medium to be treated. Constant current operation (variable voltage) is recommended. This type of operation ensures that the current density and thus the performance of the BDD Cell is constant.

How are BDD Cells to be cleaned?

Scaling reduces the performance of BDD Cells. Severe scaling can destroy the boron-doped diamond electrodes. The cell can be cleaned with any commercially available descaler. Diluted hydrochloric acid or acetic acid is recommended for industrial applications.

When does the BDD Cell need to be cleaned?

The current and voltage consumption of BDD Cells also indicate scaling. If the cell is operated at constant current, the voltage will increase with increased scaling. If the cell is operated at a constant voltage, the current will decrease as the scaling increases. Important: Monitor current and voltage.

Can BDD Cells be destroyed?

Severe scaling leads to a strong reduction of the electrochemically active electrode area. Current density hot spots develop, which can destroy the electrodes, especially the contact electrodes. How can this be avoided? Regularly reverse polarity and/or clean (descale); descale medium (electrolyte) before electrochemical treatment.
If the BDD Cell is energised and filled with the medium to be treated (electrolyte), but there is no flow, then the medium becomes increasingly hot (starts to boil). If this effect lasts longer, the plastic housing of the cell can be deformed, especially at high current densities, and the cell becomes leaky. How can this be avoided? Monitor flow and/or temperature.
Solids, e.g. stones, gravel, sand, in the medium (electrolyte) can clog BDD Cells. This leads to the same effects as scaling. However, solids can also lead to abrasive effects at the electrode surfaces and destroy the electrodes. How can this be avoided? Filtration.

What does reverse polarity mean?

Scaling on the surfaces of the electrodes is caused by lime (main cause) but also by other substances in the medium to be treated (electrolyte). What these substances are ultimately depends on the composition of the electrolyte. The BDD Cell or the electrodes installed in it are operated with direct voltage (positive and negative pole). If the polarity is reversed at regular intervals, i.e. the positive pole becomes the negative pole and the negative pole the positive pole, the scaling falls off the electrode surfaces. The reversing of the polarity can be carried out automatically by a polarity reversal unit. Caution: If the scaling is too strong, reversing polarity is no longer sufficient and the cell must be cleaned (descaled).