Pathfinder Systems was approached about an application for a blower at 7600 feet above sea level. These applications typically require additional blower cooling, such as heat exchangers or oil coolers.
After reviewing and sizing the blower for this application, our options included the Tuthill 6015 QX and the Tuthill 5511 PD Plus. The Tuthill 6015 QX is a tri-lobe blower.
For the Tuthill 6015QX, although the outlet temperature was 311F running / 372F relief, it was only 80% of the blowers maximum temperature limit. The blower was operating at 79% of maximum speed. We considered other brands of blowers, but without an oil cooler, the QX blower is the only blower applicable for this application. The efficiency of the QX combined with its more rugged construction, allowed the QX to operate without any additional cooling equipment.
At 311F / 372F, there is no oil that can sustain its integrity for any significant amount of time. Oil changes at that temperature are going to be extremely frequent. By switching to a 5511 PD Plus, the outlet temperature rose to 348F/428F. Although the temperature was higher, the PD Plus offers a cooling coil within the oil sump. This will allow the blower to continuously run at 348F (estimated un-cooled oil temperature of 278F).
For an oil temperature of 278, oil changes needed to take place every 94 hours. With the addition of the cooling coil, the oil temperature was lowered to 175F. Oil changes are now every 6000 hours with Pathfinder's Synthetic Blower Oil.
For applications utilizing Food-Grade oils, oil changes are 3-4 times more often because the oil does not have the durability of industrial synthetic oils.
Cooling coils can make the difference between weekly oil changes and quarterly oil changes.