Facility fire handled safely, plant running normally

As was reported in the media yesterday, there was a minor fire at CRRA’s Mid-Connecticut Project trash-to-energy plant in Hartford.

Here is a full report on the incident:

At about 4:15 a.m. on July 30 a fire broke out in the scrubber atomizer housing associated with Boiler 13. The boiler is one of three located in the plant’s power-generation building (the other building is the waste processing facility, where trash is turned into the fuel used to generate electricity). Each boiler is serviced by a scrubber which cleans pollutants from the boiler’s emissions before they go to the smoke stack. As a result of our control systems, emissions from all of our trash-to-energy plants consistently are cleaner than state air-quality standards require.

The scrubber atomizer is used to spray a lime slurry into the flue gas stream to neutralize the acid gases generated during the trash-to-energy process. Wednesday’s fire occurred in a housing above the scrubber unit. The fire did not occur within the pollution control treatment train and did not enter the flue gas stream or the smoke stack.

Employees of Covanta Energy, which operates the plant for CRRA, called the Hartford Fire Department because of the smoke caused by the smoldering fire. The fire was out within two ours, and firefighters left the site at about 10:45 a.m. Covanta's safety procedures worked perfectly, no employees were injured and there was no need to evacuate the building.

The fire was caused by lubricating oil that had leaked into insulation in the housing above the scrubber atomizer unit. The atomizer has associated with it an ancillary piece of equipment – a gearbox – that operates the atomizer. The gearbox is located in a plenum above the scrubber unit. The gearbox is lubricated with oil, some of which leaked from the gearbox and migrated into the insulation. The oil eventually ignited as surfaces in the housing directly above the scrubber atomizer unit reach temperatures of 300 to 400 degrees Fahrenheit.

This incident did not interrupt facility operations. The trash kept moving, and the other two boilers continued to generate electricity. Boiler 13 was returned to service at 9:45 p.m. Wednesday, meaning it was out of service for less than 18 hours.