Our tests and tests have clearly demonstrated that the most effective method of clearing blocked DPF / FAP / KAT filter channels is cleaning with a high-pressure water jet with a well-chosen detergent.
On the other hand, chemical cleaning turned out to be the worst and most invasive method.
Hydrodynamic cleaning alone was the only chance to get rid of all kinds of solid particles from the inlet channels of the filter cartridge.
The spray liquid stream in the machine is directed from the outlet side of the filter, the open outlet channels, then water with detergent passes through the micropores in the walls dividing the channels into the blocked intake channels.
The filter is fastened in the machine vertically, with the outlet side from the top (where the water jet is applied).
This arrangement of the filter allows cleaning of the inlet channels of the filter, which in this position have open channels at the bottom, where contaminated water together with all deposits can easily escape outside the filter.
Other methods did not guarantee such effectiveness, while maintaining safety for the filter cartridge.
Thermal treatment in an induction furnace allows to burn soot in the filter channels to form ash, unlike in the environment of the exhaust system, where the soot particles react with nitrogen dioxide from the exhaust gas, from which carbon monoxide and nitric oxide are formed. These, on the other hand, combine with oxygen form carbon dioxides and nitrogen oxides escaping through the outlet channels from the system.
Simply put, soot oxidizes there to a gas form, which is much easier to get out of the filter than ash.
In addition, the effectiveness of this method depends a little on luck.
Too short processing time means that the heavily compressed soot located inside the filter core will not be burnt and the filter will not regain full efficiency. On the other hand, too long heating time leads to degradation of the filter core. After heat treatment, the filter cartridge channels are blocked with ash, which, depending on the previous soot combustion process, is more or less suitable for blowing with compressed air.
Ultrasonic cleaning only deals with slightly or moderately soiled filters.
Unfortunately, most of the filters come in a bad condition.
In such filters, water with ultrasounds does not go through all the channels, leaving some of them untouched. In this method, a final blow with compressed air is also needed, which removes dissolved deposits from the filter cartridge channels more or less successfully.
Pneumatic treatment is not good at cleaning filters contaminated with oil and with seared carbon deposits.
This is not a rare case. Turbocharger failure, injections often lead to DPF oil flooding.
In addition, in this method it is necessary to cut the filter, remove the filter core, and then weld.
Regeneration in service mode only makes sense in cars with a really low mileage, where in blocked channels soot is the major part. Such soot is easy to burn into a gas form.
In cars with over 100,000 km, such a procedure very rarely turns out to be effective.
The burned soot releases only a small part of the filter channels, the remaining part is still blocked with ash.
Cleaning with chemical preparations is a real torture for the filter cartridge.
In most cases, the chemical dissolves and blends with the filter's solid particles, blocking it to a greater extent. In many cases, the filter cartridge is mechanically damaged.
Thanks to the experience gained, we chose the hydrodynamic cleaning method.
As the first step, we focused on eliminating potential disadvantages, i.e. poorly selected detergent, or too much compressed air in the liquid working stream.
To meet the challenge, we have developed our own detergent and cleaning machines.
As a result of our actions, our own technology was created.