Biomass Boiler
Implementing a secure, uniform site-wide system for enhanced safety and emergency response.
Challenge
Norwich University is a private military college, established in 1819 and serves over 2,100 students. Their campus-wide energy plan included a biomass boiler. Hallam-ICS was the mechanical, electrical and plumbing engineering firm chosen for facilitate displacement of the existing oil boilers with a biomass (green wood chips) boiler plant.
Solution
We coordinated our design with the needs for material handling, including an early study of the truck unloading, fuel storage and fuel handling systems. This site was particularly challenging as we had to cut the facility into a hill, avoid an existing roadway, achieve a specific storage amount while respecting the limitations of fuel handling equipment. Also, the ash handling system we developed in conjunction with the equipment vendors included a mixture of pneumatic conveyance (for the ash in the electrostatic precipitator) and enclosed augers (for the boiler ash).
We worked closely with the various equipment vendors and control system integrators to provide a system that balanced simplicity, reliability, cost and enough automation to allow the owner to staff the plant for two shifts per day.
There are two identical boilers on this project, each producing saturated, 125 psig steam. Each boiler is rated at 400 boiler horsepower (about 13,000 pounds per hour). They share an electrostatic precipitator and chimney. One interesting component of this project included our analysis and reporting on the existing ~120ft tall masonry chimney (circa 1960) which was serving five oil-fueled boilers. We analyzed the ability of this stack to serve the biomass boilers in addition to the oil-fueled equipment and the various risks. Hallam-ICS secured a variance from the State code official to allow the mixing of solid and liquid fueled appliances (contrary to NFPA 211 rules).
Results
Our team accomplished the following:
- Designed a biomass boiler plant featuring two 400-boiler-horsepower units with shared electrostatic precipitators and a chimney, producing 125 psig saturated steam for Norwich University’s energy plan.
- Secured a state variance to integrate biomass and oil-fueled systems within an existing 120-ft masonry chimney, overcoming NFPA 211 restrictions.
- Engineered complex material and ash handling systems, balancing site constraints like hillside excavation and equipment limitations while ensuring reliable automation and cost efficiency.
