Comparative measurements in the laboratory with the test rig and at an engine test rig with welas ^® particle measurement technology resulted in a large compliance of the respective results.

Donaldson is one of the leading providers of filtration systems worldwide. One field of activity is the development of closed crankcase ventilation systems. In reciprocating piston engines, these contribute to the protection of the engine and environment: with the combustion process, so-called blow-by gases reach the crankcase bypassing the piston rings. The gases are contaminated by oil, fuel, and soot particles and can create an unwanted overpressure in the piston chamber. The blow-by gases are diverted over crankcase ventilation. For reasons of environmental protection, the ventilation may not happen outwards. Instead, the gases are led through a closed circuit again into the intake area of the engine. To preserve the engine components, the oil portion in the blow-by gas must be reduced as far as possible by using an oil separator. This is done with the help of a blow-by gas filter.

Testing of oil separators

Testing of oil separators in laboratory and practice Particle measurement technology of Palas^® was used at a parallel test of oil separators and filters under practice and laboratory conditions. On the one hand, the Donaldson developers accomplished laboratory measurements with the welas® digital 2000 with heatable cuvette and the dilution system KHG 2010, both being integrated into the HMT 1000 test rig. On the other hand, measurements were carried out with the in-situ particle measurement technology welas ^® 1000 and KHG 2010 directly at an engine test rig of a truck manufacturer.

The high compliance rate of in-situ and laboratory measurements

After the mass flow of the gas, the temperature of the gas and filter, as well as the particle concentration and particle number distribution in the blow-by gas, had been characterized, the particle size distribution and concentration and the separation efficiency were measured with the test system in the laboratory as well as at the test rig of the truck manufacturer, at different positions of the engine. The result of the measurements: the oil separators show high efficiency. The measuring data showed a high compliance rate regarding the particle size distribution of the oil droplets and the separation feature.