Dear Shin Ho Kwon,

SLR is defined as material mass flow divided by air mass flow.

As 50 micron cement has a higher suspension velocity than 15 micron cement, the required air velocity is higher for the 50 micron cement than for the 15 micron cement.

Assuming the same material mass flow for the 50 micron and the 15 micron cement, then:

50 micron cement:

SLR(50) = material mass flow / air mass flow(50)

15 micron cement:

SLR(15) = material mass flow / air mass flow(15)

As air mass flow(50) > air mass flow(15), then SLR(50) < SLR(15)

The maximum achievable SLR is a (partly) result of the solid loss factor (SLF), which determines the energy losses of a defined material and thereby the pressure drop for a given installation and air mass flow.

There is no basis to consider a “better” or “worse” SLR.

In general, the higher the SLF, the lower the SLR at the same conveying conditions s.a. the ratio air velocity/suspension velocity.

In terms of pneumatic conveying, 50 micron cement is considered a different material than 15 micron cement, as alumina is also a different material.

Comparing conveying parameters in pneumatic conveying is always complicated, because of the great number of variables, influencing each other.

Comparing one parameter, requires all the other parameters to be equal, which is very difficult to achieve.

I am afraid that it is not only your chaos.

The number of articles, where multiple theories and approaches are presented, are numerous but not really leading to a common and consisting understanding let be an user friendly calculation method.

Success

Teus ■