The oil flows directly between the control walls at high speed, reaches the suction side of the right tank, and then flows directly into the suction port.

A cross section of the oil flow in the center of the tank. Other cross-sections facing the side of the tank will show more blue areas, indicating lower oil flow speeds. These results indicate that the oil circulation efficiency in conventional tanks is poor. Since not all the oil is flowing, the actual retention time is 5 to 10 minutes instead of the assumed 30 minutes.

Water in oil

Many water problems in paper machines are caused by the formation of condensate in the return line or leaks from the cylinder steam connections. The bearing manufacturer recommends a water content of 200 ppm (0.02%). However, in practice, this percentage is usually several times this percentage, and may be high in some cases.

Modern high-speed machines are prone to water problems due to large temperature changes in the return line and dry thin oil lubrication of wire oil.

Water, whether it is tiny droplets or water mixed with oil, will reduce the efficiency of dry thin oil lubrication by destroying the lubricant film that separates and protects the rolling elements of the bearing. The higher the bearing load, the more destructive it is.

Water also shortens the life of the oil by altering the chemical properties of the constituent materials, such as its corrosion resistance and extreme pressure additives-a problem exacerbated by high temperatures.

The effect of moisture in the lubricating oil is derived from the test results on a Finnish paper machine.