Cleaning methods for diesel particulate filters, Part 1 Chemical DPF cleaning

Chemische Reinigunsmittel & Additive für Dieselpartikelfilter

(Machine Translation, read the original version here)

Today they exist in masses, cleaning companies for diesel particulate filters [DPF]. While in 2011 there were still 3-4 companies that developed effective cleaning techniques for diesel particulate filters in close cooperation with the manufacturers and offered them on the market, the market looks completely different today.

Many suppliers are active on the market today with different methods, which are not always covered by the term “cleaning technology”. A veritable price dumping has developed in this sector in recent years. In this series of articles we will show you why cheap is not always the same as good. In this series of articles we compare different DPF cleaning methods.

How effective are these, what are the advantages and disadvantages, and what are the potential dangers of each?

Chemical DPF cleaning

….this is a chemical cleaning fluid with which a cost-saving cleaning of car diesel particle filters in the installed condition should be possible. Not to be confused with additives that are added to the fuel (also shown on the cover picture), which is another matter.

Application

Using a probe and a pressure gun, the cleaning liquid must be applied to the surface of the filter elements inside the filter at a pressure of 6 – 8 bar.

Cleaning a particle filter with chemical cleaning fluid.

This requires appropriate access to the inside of the filter, which is usually achieved by unscrewing the temperature or pressure sensor of the diesel particulate filter.

The probe is inserted through this opening and the cleaning liquid is injected with several pressure surges at intervals of approx. 10 seconds. In order to reach the entire surface of the filter, the probe should be moved back and forth several times during injection. After injecting the cleaning liquid (approx. 1 L), the filter must be rinsed with a special rinsing liquid using the same method.

The cleaning liquid should dissolve the deposited soot and can be burned during normal regeneration. Accordingly, a “normal regeneration” according to the manufacturer’s instructions is necessary after the flushing process. (Replace the sensors before)

Advantage
  • No need to remove the filter
  • Short service life of the vehicle due to low cleaning time
Disadvantages
  • The cleaning liquid is injected uncontrolled (blind) into the DPF, no guarantee that the cleaning liquid reaches all chambers of the filter. Often only the first centimetres of a channel are exposed to the liquid.
  • Damage to the engine due to misfiring when cleaning fluid enters the engine combustion chamber.
  • Should only be carried out by specialist workshops,
  • Special tools required, pressure gun with adjustable pressure value, min. 6-8 bar
  • Risk of sooting of the filter and the filter surfaces
  • During the subsequent regeneration the soot is burnt to ashes, which continue to remain in the filter and inevitably lead to an overload/clogging of the filter at some point. If the filter is filled with ashes, then cleaning with a chemical cleaning fluid will not help.
  • The cleaning fluid is highly toxic and corrosive, harmful to the environment, as pollutants can be released uncontrolled into the environment during combustion.
  • Experience shows that after approx. 10.000 km the filter is clogged again.
Conclusion

The use of chemical cleaning fluid can be used to support regeneration, in which the soot is burnt to ashes.

But… the ash produced by the combustion (during regeneration) remains in the filter and eventually leads to an overload/clogging.

Further descriptions of cleaning methods will follow in the next few weeks, here is an outlook on the next topics:

(PART 1, this article) CLEANING WITH CHEMICALS

(PART 2) CLEANING WITH COMPRESSD AIR

(PART 3, upcoming) CLEANING WITH LIQUID

(PART 4, upcoming) CLEANING WITH OVENS

(PART 5, upcoming) THERMODYNAMIC CLEANING IN COMBINATION WITH WET CLEANING…