Characteristics of several parameters of high efficiency filtration equipment

I. Specification classification of equipment

1. Common specifications in China: coarse efficiency, medium efficiency, high efficiency, high efficiency, and sub-efficiency.

2. European common specifications: G-F-H-U four levels.

II. The filtration efficiency of the equipment

It can be simply explained by a formula: filtration efficiency = amount of dust captured by the filter ÷ amount of dust in the upstream air = (amount of dust in the upstream air - amount of dust in the downstream air) ÷ amount of dust in the upstream air. The definition of this efficiency method seems to be very simple, but the meaning and value it is closely related to the test method, and the efficiency values obtained by different test methods cannot be compared directly, so when we talk about efficiency we have to explain what test method is used for testing.

III. The rated airflow of the equipment

The so-called rated air volume refers to a certain volume of airflow through the filter in a unit of time, the domestic general use of m3/h as this unit of air volume, while foreign countries are using the imperial unit of air volume cfm (cubic foot per minute) to express, that is, ft3/mim cubic feet per minute, the two are converted to 1cfm ≈ 1.7m3/h. And in the same In the case of the same windward cross-section, the larger the air volume that can be passed through the equipment, the better, which means that it has a large filtration capacity.

IV. Surface speed and filtration speed of the equipment

1. The so-called surface speed refers to the speed of the airflow through the windward section, expressed in m/s; surface speed = air volume ÷ windward cross-sectional area.

2. The filtration speed refers to the speed of airflow through the filter material, expressed in cm/s; filtration speed = air volume ÷ filter area.

3. The filter area in the above formula refers to the area of the filter material used. Only when the filter material is flat and perpendicular to the direction of airflow, the cross-sectional area and filter area of the filter are the same.