A pollution-control device installed in the smokestack of equipment used to run

Question

A pollution-control device installed in the smokestack of equipment used to run an industrial process measures the root-mean-square speed of pollutant particles given off by the process. If vrms exceeds a given limit, the process is shut down to prevent the release of pollutants into the air. (Consider the particles to be ideal and monatomic.) The safety operator knows that the average mass density of the particles involved in this process is 5600 kg/m3 .

Part A

Part complete

At what threshold should he set the device if the process is running at 876 ?C and the particle diameter is 10 nm ?

Part B

Part complete

As the particles rise and exit the smokestack, the 10-nm particles coalesce to an average diameter of 1.0 ?m and cool to 190?C . What is the root-mean-square speed of the particles as they exit the smokestack? (Ignore viscosity and drag.)

Explanation / Answer

a)

Mass of particle

M=pV =5600*(4/3)*pi*(10*10-9/2)3=2.932*10-21 Kg

Rms Speed is given by

Vrms=sqrt[3KBT/M]=sqrt[3*(1.38*10-23)*(876+273.2)/(2.932*10-21)]

Vrms=4.028 m/s

b)

Mass of particle

M=(5600)(4/3)*pi*(1*10-6/2)2 =5.8643*10-9 Kg/m3

M=2.932*10-15 Kg

Vrms=sqrt[3*(1.38*10-23)*(190+273.2)/(2.932*10-15)]

Vrms=2.557*10-3 m/s

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

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