| OCR Text |
Show the start-up of the pellet calibration burn, after adjusting the feeder rate gate to 50 percent open (giving 115-125 amps on the pulverizer), the airflow controls were still in the same position as used for oil. With a furnace forced draft pressure of approximate three inches water column, and the burner registers eighty percent open, the fire box was full of flame and small sparklers were observed striking the furnace screen wall tubes similar to that experienced on an oil burner with poor atomization. The best wood fires were observed as the forced-draft pressure was reduced to 0.5 inch water column and the burner registers were closed which gave us a flame length of approximately 8 feet with a clean fire. The flame appearance was bright orange and the flame tips were somewhat lazy. This firing condition eliminated the sparklers and the appropriate grey haze in the fire box was observed, indicating that the maximum amount of carbon was being burned and fly ash was present. The maximum steam rate that could be obtained, operating with maximum pulverizer current, was twenty-eight thousand pounds per hour steam flow. The mill fuel flow rate for the wood pellets was determined to be 3675 pounds per hour over the duration of the calibration burn of 116 minutes. The results of the calibration burn indicated that: 1. The refined wood pellets were easily burned in the existing installation. 2. The maximum sustained boiler capacity was approximately 28,000 pounds per hour, the limiting factor being the coal pulverizer design. 3. The wood fires were clean and stable with low visible stack emissions, had small excess air requirements, and reduced secondary velocities. 26-15 |
