The main performance parameters of the filter

The main performance parameters of the filter

1 filter accuracy

Filtration accuracy, indicating that the filters on a variety of different sizes of particles filter capacity, by the absolute filter accuracy, filtration ratio, filtration efficiency and other parameters.

① Absolute filter accuracy, refers to the size of the largest hard spherical particles through the filter (μm). Measured by the test method, reflecting the maximum pore size of the filter material.

② filter ratio β, refers to the same size of the particles in the upstream of the filter unit volume of oil, and the downstream unit volume of oil in the ratio of the number. It can accurately reflect the filters on different sizes of particles of filtration capacity, has been adopted by the International Organization for Standardization to assess the accuracy of the filter filter performance indicators.

For a particle of size X, the expression of the filter ratio βx is:

Βx = Nu / Nd

Where Nu is the concentration of particles in the upstream oil x

Nd is the concentration of particles in size x in the downstream oil.

It can be seen that the larger the βx, the higher the filtering accuracy. When the filter ratio βx reaches 75, it is regarded as the absolute filter accuracy of the filter for a certain size X particle.

③ filtration efficiency Ec, Ec can be obtained by the following formula:

Ec = (Nu-Nd) / Nu = 1-1 /β X

2 filter pressure drop characteristics

The filter has resistance. The system of oil, flowing through the filter must be pressure drop.

Filter and flow must be, the filter filter the higher the accuracy, the greater the pressure drop; flow must be, filter the larger the filter area, the pressure drop is smaller; the greater the viscosity of the oil, the greater the pressure drop.

The pressure drop allowed by the filter element is the maximum pressure drop that the filter element can not withstand structural damage. In the high-pressure system in the stable work, the filter is only where the pressure drop of oil, rather than pressure.

The pressure drop of the oil flowing through the filter is largely determined by the test and empirical formula.

3 filter capacity of the filter

The amount of particles that can be filtered and accommodated before the pressure drop of the filter reaches the specified value. This is an important indicator of the actual time that the filter can be used continuously. The larger the capacity, the longer the replacement or cleaning interval. In general, the filter size, that is, large filter area, the scale capacity is proportional to increase. This indicator can be determined by multiple performance tests.