Glossary
HRSG and gas path
Multi-cyclone
Also known as multiclone, multicyclone, cyclone bank.
A multi-cyclone (or multiclone) is a parallel array of many small cyclone separators housed in a single enclosure. The arrangement gives higher collection efficiency than a single large cyclone of the same gas-handling capacity, because efficiency improves as cyclone diameter decreases. Multi-cyclones are common as pre-cleaners ahead of ESPs and baghouses on coal-fired and biomass plants.
Operational issues
- Tube-to-tube flow imbalance — uneven gas distribution leaves some cyclones overloaded and under-performing
- Individual cyclone pluggage — a single fouled cyclone bypasses gas to its neighbours and reduces overall collection
- Common hopper bridging below the array — see hopper
- Vortex finder fouling in individual tubes
Cleaning
Sonic horns installed on the common housing project sound across the cyclone array. They keep individual cyclone walls free of build-up and prevent the common hopper from bridging.
Related terms
Related terms
- Cyclone separatorA cyclone separator removes particulate from a gas stream by centrifugal force. Wall build-up and re-entrainment from the dipleg are the dominant operational issues.
- Cyclone diplegThe cyclone dipleg is the vertical pipe at the bottom of a cyclone separator that carries separated solids back to a hopper or recirculation circuit. Pluggage is a chronic operational issue.