AUTOMATIC WATER COOLING FOR TEMPERATURE EXCURSIONS IN MULTIPLEHEARTH INCINERATORS

摘要

The control of slag formation and temperature excursions in multiple-hearthrnincinerators are well known operational problems within the industry. Autogenousrnsludge combustion in multiple hearth incinerators can have high hearth temperaturernexcursions. Slag formation has been shown to be a function of temperature. In orderrnto control peak excursion temperatures without having to use massive amounts ofrncooling air, an innovative, low cost, automatic water spray cooling system for multiplehearthrnincinerators was developed at the Seneca Wastewater Treatment Plant.rnFor cooling, the use of supplemental water requires about four times less mass thanrnair. Also, any water injected into the incinerator for cooling temperature excursionsrnwill condense in the wet scrubber; thus, the ID fan and motor does not have anyrnincrease in mass loading. The sprays are designed for 2 to 8 gpm water flow. Thernwater spray system has been in successful operation since January 1998. Thernequipment and installation cost for the full-scale, pilot study water spray system wasrnabout $35,000, which will be lower for future spray systems. The use of supplementalrnwater spray cooling, with air atomization to reduce peak excursion temperatures,rnincinerator scrubber bypasses and hard slag formation was the focus of this processrnstudy.