Taking synchronous operatiion of both oil-applying equipment and oil-purifying equipment as example
the principle and method of design and calculation for oil-purifying equipment have been described
and practical example of calculatiion being given. It is obtained from theoritical analysis that the methods which can be used to ensure the quality of oil are as follows: (1) increasing the volume of oil tank; (2) decreasing the impurities mixed-in oil; (3) selecting and using highly effective oil-purifying equipment; (4) selecting and using oil-purifying equipment with large flow quantity.