sludge2energy Process Variant Steam Boiler

With this design version „Steam Boiler“, the exhaust heat is made available for utilisation on a higher energy level in the form of power and steam.
 

 
Brief description of the technology

• Sludge acceptance and storage area for dewatered sewage sludge (1) to balance varying supply volumes
• Partial drying in a contact dryer (2) for auto-thermal incineration of the sludge
• Flexible combustion control including adjustable conveying line for controlled sludge input (3)
• Condensation of dryer vapours, introduction of vapours/air into the fluidised bed furnace (4) as combustion air
• Stationary fluidised bed furnace (4) with continuous discharge of bed material and contaminants
• Burner for plant start-up and shutdown and balancing unsteady operating states
• Waste heat boiler (5) for heat transmission from flue gas to useable vapour
• Energetic utilisation of the vapour via a counter-pressure steam turbine (12) with generator
• Utilisation of the exhaust steam for heat supply to internal consumers, such as sludge dryer
• Staged combustion air system to minimize contaminants, such as dioxins, carbon monoxide, organic pollutants and nitric oxides 
• Denitrification according to the selective non-catalytic reduction (SNCR) method as first stage of flue gas cleaning
• Fabric filter for pre-separation (6) of the phosphorus-rich flue ash from the flue gas
• Dry flue gas cleaning (7) with sorbent dosing to remove acid pollutants, dioxins and heavy metals (e.g. Hg)
• Fabric filter (8) (sorption filter) to remove reaction products and dust from the flue gas
• Recirculation of the sorption residues to improve separation efficiency and reduce sorbent consumption
• Emission measurement station in chimney (11) for the control of all legal emission limits
• Ash discharge and storage of reaction products (10) separately from phosphorus-rich bed ash, boiler ash and pre-separated ash (9)