Frequently Asked Questions
What is the difference between a hydraulic and a gearbox backdrive?
How much polymer should I use?
How do I know what differential speed to run?
What is a normal pressure reading?
What does leading or lagging mean?
How fast should I run my machine?
How often do I need to change oil and filter?
My filter keeps showing “RED” what can cause this?
My oil looks milky, what can cause this?
How often do I need to rebuild it?
What is the difference between a rebuilt, a repair and a bearing change?
Do you sell parts for other centrifuge brands?
Do you repair other centrifuge brands?
How long can I store a machine without running it?
Q: How does a centrifuge work?
Centrifuges are custom designed based on Material of Construction constraints imposed by design and operating conditions (typically pressure and temperature) of the process. Further, such equipment is customized to conform to the area classification of the process environment.
Q: What is the difference between a hydraulic and a gearbox backdrive?
The hydraulic has more torque, is more efficient and allows full torque and differential speed even at standstill. It is the most advanced backdrive and also works completely independent of bowl speed and direction.
Q: How much polymer should I use?
Use bench tests to determine the proper polymer. Then start at a high dose and when the process works well, gradually reduce the dosage until the centrate turns slightly gray. Then increase the dose slightly. This is your most economical setting.
Q: What is differential speed?
The difference in speed between bowl and scroll. Higher differential allows for cleaner centrate and more GPMs. Lower differential gets drier cake.
Q: How do I know what differential speed to run?
This depends on the product. After the unit is set up initially, start with a higher differential and then gradually reduce it until the centrate shows some particles in it. Then slightly increase the diff speed.
Q: What is a normal pressure reading?
On high torque hydraulics (4 digit Rotodiff models) operating range is 50 bar to 200 bar continuous.
Q: What does leading or lagging mean?
A leading scroll is faster than the bowl, a lagging scroll is slower than the bowl. To change it, reverse the direction of the bowl (main drive). This is not possible with gearbox back drives.
Q: How fast should I run my machine?
Depends on the product settling speed. Start with 90% speed for wastewater sludge for example. Once all parameters are set and the process works well, go to max speed. Then without changing other parameters, take a sample, then reduce speed 100 rpm at a time and wait 10 minutes before taking next sample. The preferred speed is the lowest speed at which acceptable process can be maintained. Higher speeds will cause more stress on the machine.
Q: How often do I need to change oil and filter?
Every 4000 hours or twice a year whichever occurs first.
Q: My filter keeps showing “RED” what can cause this?
Water (condensation) in the oil will cause this. Sample the oil frequently to check for evidence of water. Contamination decreases hydraulic system life.
Q: My oil looks milky, what can cause this?
See previous answer
Q: How often do I need to rebuild it?
Recommended inspections are at 10,000.00 hours or every 2-3 years. Rebuilds at 15,000 hrs.
Q: What is the difference between a rebuilt, a repair and a bearing change?
Bearing change is a preventative maintenance only, it does not repair anything. A repair includes complete inspection, balancing, new bearings and seals and normal wear repair. A rebuilt will include all the above and also bringing the unit up to original spec and condition.
Q: Do you sell parts for other centrifuge brands?
We stock a large amount of competition parts that either meet or exceed OEM quality.
Q: Do you repair other centrifuge brands?
We repair all brands of decanter centrifuges.
Q: How long can I store a machine without running it?
See storage procedures under “installation information”