Members from BHP Billiton LTD, have approached filtration consulting, to design a cyclone separator system for a process involved in the production of zinc oxide particles. The clients has also asked for advice on the use of bag filters as a standalone system, or in conjunction with a cyclone separator system. The filtration system must have a collection efficiency of 95% of the zinc oxide particle from a gas flow at 1000°C and with a flow rate of 3820 (Nm^3)/hr.
One of the most common particle filtration devices used amongst many industries is a cyclone separator. These simple devices use centrifugal force to separate larger particles from a gas flow. Due to the low complexity of a cyclone separator, and the fact that no moving parts required for the operation of the cyclone senators, they are relatively cost efficient. For the smaller sized particles, a popular filtration device used in industry is bag filters or baghouses, as they have a collection efficiency of approximately 99%. Due to the operational manner of the baghouses, they are relativity expensive to install, as each bag costs approximately $45, if not more.
The design of cyclone separators is made on the basis Stairmands empirical data from 1951. …show more content…
Stairmands data is based on a cyclone separator with a characteristic diameter of 203mm and a height of 812mm. The flow rate is used to determine this characteristic diameter, which then along with the flow rate, change in density and dynamic viscosity is used to determine the scaling factor. The scaling factor is then applied to the particle size distribution, and hence the collection efficiency is determined. To ensure correct flow through the cyclone, the pressure drop is calculated, and is required to be no more the one kilopascal. Reynolds and Stokes numbers are used to determine the particle behaviour in the new design of the cyclone compared to Stairmands
One of the most common particle filtration devices used amongst many industries is a cyclone separator. These simple devices use centrifugal force to separate larger particles from a gas flow. Due to the low complexity of a cyclone separator, and the fact that no moving parts required for the operation of the cyclone senators, they are relatively cost efficient. For the smaller sized particles, a popular filtration device used in industry is bag filters or baghouses, as they have a collection efficiency of approximately 99%. Due to the operational manner of the baghouses, they are relativity expensive to install, as each bag costs approximately $45, if not more.
The design of cyclone separators is made on the basis Stairmands empirical data from 1951. …show more content…
Stairmands data is based on a cyclone separator with a characteristic diameter of 203mm and a height of 812mm. The flow rate is used to determine this characteristic diameter, which then along with the flow rate, change in density and dynamic viscosity is used to determine the scaling factor. The scaling factor is then applied to the particle size distribution, and hence the collection efficiency is determined. To ensure correct flow through the cyclone, the pressure drop is calculated, and is required to be no more the one kilopascal. Reynolds and Stokes numbers are used to determine the particle behaviour in the new design of the cyclone compared to Stairmands