Eugene/Springfield Water Pollution Control Facility 1984-1991

New Search

Page 50 Section F: EQUIPMENT MAINTENANCE factory bearings, but in one week, the motor failed again. Staff replaced the two bearings with a large thrust bearing capable of withstanding 68,000 pounds of thrust; but another failure occurred within six months. Finally, the bearing was re- placed with a spherical thrust bearing, and the grease lubrication system was replaced with an oil lubrication system. The change was successful, and the other W2 pumps were subsequently modified as well. In August 1989, the first W2 pump to receive the modified spherical thrust bearing and oil Tube systemwas pulled to replace the oil seal and was checked for bearing wear. The bearing showed little wear after two years of operation. In October 1988, one of the W2 strainers was disassembled for inspection and was found to be rusted and etched. Staff coated the affected areas with a fiber resin to protect it from future corro- sion. WASTE GAS BURNER The instrumentation work group researched, de- signed, and installed new waste gas burner con- trols. ENGINATOR REBUILD The wastewater treatmentplanthas two electrical generators rated to produce 420 kw that are pow- ered by diesel engines and are modified to run on methane gas. Methane is a waste gas that is pro- duced as a byproduct of the process of digesting sewage sludge. By using the waste gas to run the enginators, the plant can generate about 25 per- cent of the electricity needed to operate the plant. In the fall of 1990, the plant began experiencing drops in the generator output. After checking the engine timing firing and fuel source, plant me- chanics took compression readings for each of the eight cylinders on both engines. They found that cylinders on both engines had compression read- ings of 150 pounds per square inch (psi) -normal compression isbetween225 and250psi. Cummings Northwest confirmed the test results and recom- mend rebuilding the top ends of the engines. The rebuilt on Enginator 1 consisted of installing new pistons, putting sleeves in the cylinder walls, re- placingvalves, grinding valve seats, and replacing lifters rocker assembly and other parts as needed. The rebuild took from January to April 1991 and cost more than $57,000. The engine again is ca- pable of producing over 400 kw. PLANT COMPUTER SYSTEM After analyzing the plant's process computer sys- tems, the instnuentation work group found so many problems, group members recommended that anew distributed process control computer system be installed. The group assisted in writing the specifications for the new system. WILLAKENZIE PUMP STATION By repairing in-house six invertors at the Willakenzie lift station, the plant saved approxi- mately $100,000. Contractor estimates to repair the inverters were about $20,000 apiece, but plant electricians were able to complete the repairs for $2,000 each - nearly a $100,000 savings. JUDKINS POINT PUMP STATION When the Judkins Point discharge pressure line broke, maintenance staff worked quickly to repair the line. A new elbow was fabricated by the staff, and with assistance from the Facility Maintenance section and from Public Works Maintenance staff, the repair was completed with minimal sewage bypassing the station. The W2 pumping system was improved with bearing and lubrication modifications.