In a 1 m3 deposition chamber, the aerosol flux though the air was 15 mg/(m2 s) a

Question

In a 1 m3 deposition chamber, the aerosol flux though the air was 15 mg/(m2 s) and the mass concentration measured at the surface of the chamber was 0.9 kg/m3. What is the average particle size? You will have to find a reasonable value of the viscosity of air, and assume the particle has a density of 1 g/mL (typical assumption without further information). In a 1 m3 deposition chamber, the aerosol flux though the air was 15 mg/(m2 s) and the mass concentration measured at the surface of the chamber was 0.9 kg/m3. What is the average particle size? You will have to find a reasonable value of the viscosity of air, and assume the particle has a density of 1 g/mL (typical assumption without further information). In a 1 m3 deposition chamber, the aerosol flux though the air was 15 mg/(m2 s) and the mass concentration measured at the surface of the chamber was 0.9 kg/m3. What is the average particle size? You will have to find a reasonable value of the viscosity of air, and assume the particle has a density of 1 g/mL (typical assumption without further information).

Explanation / Answer

From the aerosol distribution we know that the particle size is based on thermophoretic or overall deposition velocity

We can consider the same from diffusion velocity

now deposition velocity V= particle flux/upstream particle concentration

now particle flux= 15mg/m^2.s = 15*10^-6Kg/m^2.s =.000015kg/m^2.s

particle concentration in the chamber= .9kg/m^3

using values the deposition velocity =.000015/.9 = 1.67*10^-5m/s

From Opiola et al(1990) wwe know that when particle diameter>1micrometer then deposition velocity is lower than standard value.

using particle density and mass concentration we get the number of particles in the chamber of 1m^3

number of particles= 1000/.9= 1111 [1g/ml=1000kg/m^3]

that means 1111 particles per m^3

Now for 3500particle/m^3 means particle radius in .3 to.8 micrometer

The concentration defines that average particle sixe is .1 to.3 micrometer

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.