Dust collectors that use liquid are commonly known as wet scrubbers dust collectors. In these systems, the scrubbing liquid usually water comes into contact with a gas stream containing dust particles. The greater the contact of the gas and liquid streams, the higher the dust removal efficiency. There is a large variety of wet scrubbers dust collectors however, all have of three basic operations, gas-humidification, gas-liquid contact and gas-liquid separation. The cleaned gases are normally passed through a mist eliminator to remove water droplets from the gas stream. The dirty water from the scrubber system is either cleaned and discharged or recycled to the scrubber. Dust is removed from the scrubber in a clarification unit or a drag chain tank. In both systems solid material settles on the bottom of the tank. A drag chain system removes the sludge and deposits in into a dumpster or stockpile.