EFC hydraulic oil filters in the wood industry FRIESS electrostatic oil cleaning system
In a large wood processing company, various hydraulic systems are used to convey and clamp the wooden parts to be processed. Due to the very high dust load throughout the plant, the hydraulic oil used becomes contaminated fairly quickly.
Problem
The head of the maintenance department was not satisfied with the cleaning performance of the hydraulic filters previously used. In order to improve the oil cleanliness and extend the service life of the hydraulic oil, an off-line filter unit with a pore size of 5 µm was used. This off-line filter unit was regularly connected to the various hydraulic systems.
Despite the relatively high consumption of filter elements, the overall cleaning performance was not satisfactory. Due to the level fluctuation that occurred during operation, the air filters on the individual hydraulic tanks constantly sucked dust-laden air into the tank and pushed it out again. As a result, the actual dirt ingress was higher than the cleaning performance of the bypass filter unit.
Solution: EFR hydraulic oil filter (electrostatic oil cleaning system)
An alternative solution was sought in order to improve the oil condition so that the hydraulic systems used could be operated as trouble-free as possible. After contacting the factory representative of FRIESS GmbH, the maintenance department decided to use an electrostatic oil cleaning system (EFC hydraulic oil filter) model D8. Oil samples were regularly taken from the hydraulic tank of a press and analysed before the EFC hydraulic oil filter was used.
Status before using the EFC hydraulic oil filter:
The particle counts in December 2013 and October 2014 revealed an extremely high level of contamination. The cleanliness code according to ISO 4406 was 23/22/19 and was therefore significantly higher than permitted for a modern hydraulic system.
In addition, the silicon content was clearly quite elevated at 21 mg/kg and 39 mg/kg respectively. All other values such as viscosity and additive content were completely acceptable.
Result of the EFC hydraulic oil filtration
After a few weeks of cleaning with the FRIESS EFC hydraulic oil filter system, another oil sample was taken from the tank on March 5, 2015. An oil analysis of the fresh oil was carried out at the same time. While the new oil from the drum resulted in a cleanliness code of 19/17/13 according to ISO 4406, the oil in the press that had been cleaned with the EFC system was significantly cleaner. The particle count showed a code of 16/14/11. The contamination in the tank was reduced by well over 90 % compared to the period before electrostatic cleaning was used. Even compared to new oil, the electrostatically cleaned used oil is significantly cleaner. The silicon content was reduced from 21 mg/kg to less than 6 mg/kg. The additive balance was completely in order after cleaning, as were all other values. The cleaned oil can continue to be used without any problems.
Summary:
- Even compared to new oil, the electrostatically cleaned used oil is significantly cleaner.
- Contamination in the tank was reduced by well over 90 % compared to the period before electrostatic hydraulic oil filtration was used.
- The content of silicon particles was reduced from 21 mg/kg to less than 6 mg/kg.
- The additive balance was completely in order after cleaning, as were all other values.
- The cleaned oil can continue to be used without any problems.