I would like to ask how to deal with part (c)? An air classifier is used to sepa
ID: 1445650 • Letter: I
Question
I would like to ask how to deal with part (c)?
An air classifier is used to separate cardboard pieces from other denser materials. It is known that: density of cardboard = 1.5 kg/L. mean diameter of the cardboard is 5 cm. air is at 50degreeC and 1 atm. Determine the density of the air. Determine the critical velocity of the air required to suspend the piece of cardboard. Other floating pieces inside the classifier take up 40% of the space in the unit. Estimate the necessary air velocity to suspend this cardboard. Qualitatively explain why the second critical air velocity is larger/smaller than the first velocity based on single particle.Explanation / Answer
a) density = pressure/(specific gas contant for air * temperature)
pressure = 1atm = 101325 N/m^2
R_air = 286.9 J kg^-1 K^-1
T = 273 + 50 K = 323 K
density = 1.1 kg/m^3