cyclones and ending just ahead of the bagging storage silos. To avoid false alarms, the sensors are insensitive to daylight. Yet to make sure all potential risks are managed, the infrared sensors pick up both “dark” embers (those between 250 and 700 degrees Celsius that can still ignite the dry meal) and what we more traditionally think of as sparks (above 400 degrees Celsius). If an incident occurs, the system uses a full-cone spray that is able to handle the high-volume flows typical of pellet mill conveying systems. Fibre is sent from the cyclones to the second hammer mill, another Andritz Sprout model with 1/4" or less screens. From this point the meal goes either to a bag house to feed the pellet mills or to the burner to heat the dryer. For start up, the plant brought in some animal bedding to fuel the burner, an exercise that gave Curran Renewable Energy other ideas. “We’ve left a spot for a shaving line just out- Energy Unlimited’s original role was to install the burner and triple-pass rotary dryer, but the company ended up managing the design, mechanical, and start up for the whole project. Seaway Timber’s fleet of Morbark and Peterson flail debarker/chippers turn the region’s mixed wood diet into pulp chips. “The chips coming here are identical to those we make for the pulp market, so it’s very flexible. We can send the chips to either depending on markets.” Chips are moved to either Seaway Timber’s reload yard in Chateauguay, New York, for shipment to Windsor in Manac trailers loaded for heavier Canadian weights, or to the pellet mill. Bark goes to Seaway’s garage and office site in Mas- sena, where a Peterson 4710B with colouring system makes landscape mulch. Once the chips hit the pellet mill yard, the incoming vans are weighed on scales re- purposed from a company gravel pit and then go to a Columbia tipper. From here a Cat wheel loader feeds a hopper bought used from the shuttered Domtar mill in Cornwall. “Aside from this piece of used equipment, it’s all new gear,” Curran adds. The hopper feeds the first hammer mill, an Andritz Sprout model with 5/8" screens con- tained in a stand-alone building. “We’re right in town at this location, so we’ve done what we can to try to isolate the noise,” he explains. This fibre then goes to a 13 x 16 foot Bak- er Roman triple pass rotary dryer supplied by The plant design includes three Andritz Sprout pel- let mills, with room for a fourth should it be needed. The pellets go to a MilPro (Law-Marot) cooling system, Andritz shaker screen, and then to the silos. The plant is designed to make pellets on a 24/7 basis. CanadianBIOMASS 19 Energy Unlimited along with one of the sup- plier’s own burner units. From the dryer, fibre is conveyed to cyclones, passing through the first of a series of Firefly AB spark detection sensors. Spark detection and fire mitigation has been an emphasis at the plant since day one. “One of the first things John (Lundell) asked me was ‘where do you want your fire’. So we designed to handle that possibility throughout the plant. The detection system we put in was a little more expensive than others we looked at, but we felt it covered more in the plant.” The Firefly system gives the plant full cover- age, starting with sensors between the dryer and side the dryer,” Curran says. “We wanted to have an outlet for our dry meal if our pellet in- ventories ever get too high, and animal bedding is a good market here. But we saw that the bed- ding we were buying was actually very close in quality to the meal we’ll be making pellets with, so we hope we can avoid putting a shaver in altogether.” Once inside the main building, pellets are made by three Andritz Sprout pellet mills. Room has also been left for a fourth down the road if needed. Pellets go to a MilPro cooling system from Quebec’s Law-Marot, through an Andritz Sprout shaker screen and then are sent across the yard to a solitary agricultural-style storage silo from Kramer Metal Products. Again, the designers left room for a second silo down the road if cash flow allows. Throughout the process, the plant maintains
Canadian Biomass August 2009: Page 19
