New method enables filter cleaning without separation of the supply or extraction pipes

Bielefeld, 07.05.2015. The soot particle filter in diesel vehicles is full of soot and ash. Does a new one have to be installed? The automobile manufacturers say so, and it can be an expensive issue, which can cost 1000 to 4000 Euros and more, depending on the brand and type of vehicle. It is much cheaper for diesel drivers to simply arrange for the particle filter to be cleaned. Together with support from the affiliated company mycon GmbH and Kipp Umwelttechnik GmbH has developed a process with which the soot particle filter can be cleaned without any separation. Cleaning automobile exhaust gas particle filters is already common practice with a variety of systems, such as a CO2 filter cleaning system from mycon GmbH. In addition however, the filter surfaces must be exposed, so supply and extraction lines often need to be dismantled and separated. This means that thermal cleaning requires a lot of time. The car filters also need to be separated beforehand and then cauterized several times, which can take several days when blowing out with compressed air and checking the differential pressure. After cleaning, the separating cuts also need to be welded together again. This method is therefore costly and takes time and can also lead to weakening of the exhaust gas system.

Fully automatic cleaning minimizes the sources of errorsBased on a method developed by Kipp Umwelttechnik 18 months ago as part of a sponsorship project on soot particle filter cleaning without separation work, the method has been developed further with the support from mycon. It works with compressed air and a substance, which is introduced into the filter. This substance is non-toxic and can even be drunk, if you can put up with the unpleasant taste. However, the cleaning results of the sponsorship project at the time only reached max. 85%, which made optimization with an additional process step necessary. Kipp Umwelttechnik GmbH incorporated experiences from previous work and plenty of know-how from the practical application of radiation technology in further development of the method. mycon contributed theoretical knowledge in the area of fluid physics and mechanical engineering. An existing prototype system was adapted and put into test operation. The comprehensive expertise brought about the turnaround for optimization of the method surprisingly quickly. The first filters were able to be cleaned thoroughly without separation. The differential pressure test results showed levels similar to those of a new filter. The weight difference between the soiled and cleaned filter also fitted in over the years. Furthermore, the active cleaning time per filter is less than 10 minutes and cleaning is also fully automatic. Kipp Umwelttechnik already arranged for the Faculty of Chemistry at Paderborn University to carry out tests on the method in order to establish the parameters that best protect the materials. The analysis showed that the new method from the company displays very good cleaning results, just like the CO2 method used by mycon. The determined results are at least on a par with the established thermal method. With both methods – both the new development and the CO2 method – a function method that protects the catalyst surfaces of the filter channels could be established. The new method also differs from attempts to clean the filter with water and additives until a cleaning result is achieved. The respective benefits extend to several areas:

  1. Unsoiled and gentle cleaning maintains the catalytic qualities of the filter
  2. Cleaning without separating and welding work retains the quality of the filter housing
  3. Risks of damage, such as caused by fusion during the burning process at temperatures of 550°and more are avoided, since the filters are only treated with a temperature of 350° after the cleaning process
  4. Quick cleaning times reduce vehicle downtime
  5. The costs for filter cleaning are reduced

Kipp Umwelttechnik and the affiliated company mycon will analyze the experience gained with the prototype system over the next weeks and will start building the first serial systems. The method will be marketed internationally from November of this year. There is already high demand in this rapidly growing market for the new, environmentally-friendly, quick and affordable cleaning method for soot particle filters.