Mitsubishi Electric Lossnay LGH-100RX3-CAN Technical Manual page 93

CHAPTER 8 Filtering for Freshness
Gravitational method
This method is used for air filters which remove coarse dust (10 µm or more). The measurement method is determined by the
gravitational ratio of the dust amount on the in-flow side and out-flow sides.
Dust collection ratio =
Specimen
Passed dust
collection filter
Colorimetric method
The in-flow side air and out-flow side air are sampled with a suction pump and passed though filtering paper. The sampled air
is adjusted so that the degree of contamination on both filter papers is the same, and the results are determined by the
sampled air volume ratios on both sides.
Dust collection ratio =
Air-feed fan
Coupling pipe
90
In-flow side dust amount – Out-flow side dust amount
In-flow side dust amount
Orifice
Window
Performance test device
Out-flow side sampling amount – In-flow side sampling amount
Out-flow side sampling amount
Coupling
pipe
Orifice
Rectifying grid
Round duct
3D 2D 3.5D
Throttle device
Dust supply
device
Manometer
Motor
Rectifying grid
Air volume
adjustment plate
Air-feed fan
Example of dust supply device
Rectifying grid
Square duct
Baffle plate
Pressure loss concentration
Coupling pipe
measurement position
Specimen
2L 2L
× 100 (%)
Dust container
Mixing blades
Dust supply outlet
× 100 (%)
Venturi pipe
Dust chamber
Air filter
7° or
less
Unit (mm)