Obiettivo Execution of a compost curing integrated plant with computerized process control.Reduction of the energy consumption of the plant and maximums income from recycled product to reduce the cost of solid waste disposal.The plant will be installed in Italy by the local authorities in Pistoia, Tuscany.The process involves composting the biodegradable organic constituents of solid municipal waste mixed with partially dewatered sludge (ratio 70:30). The mixture thus constituted has a 59 % moisture content.Daily, the plant handles 140 tonnes of solid municipal waste and 30 tonnes of sewage sludge. Once the inert substances and other recyclable constituents have been removed, the daily intake of the composting plant consists of 70 tonnes of organic material from municipal waste mixed with 30 tonnes of sludge, making a total of 100 tonnes.Composting takes place in a horizontal digester. The material is stirred periodically by a rotating and lifting mechanism and is aerated by a current of air blown or drawn in from below.The quantity of air delivered is continuously calculated by computer on the basis of the oxygen content of the mass of material, as measured by sensors distributed throughout the digester. When the oxygen content falls below 5 %, the computer instructs the ventilators to deliver more air. When the oxygen content exceeds 20 %, ventilation is reduced.The temperature at the top and bottom of the mass is measured. If there is a difference of more than 7 deg.C between the two readings the computer instructs the ventilators to reverse the air flow. Blowing air into the mass tends to dry its inner parts and to concentrate moisture in the outer layers; drawing in air tends to have the opposite effect. When no more oxygen is required and the moisture content (as deduced from the measured temperature) falls below 30%, the computer signals that the process is completed and shuts off the ventilators.The automation plant is composed of a processor which receives the signals from the local instruments and process data, driving air compressors.For each phase of the process, the exact air quantity to complete the biological stabilization of the compost will be delivered.Innovative aspects are :- A very important energy savings compared to the conventional plant, up to 40%;- Best quality of final product;- Best maintenance of the plant.The proposed plant is complementary to the actual one, studied for the treatment of the urban solid refuse.The actual plant consist of a drum for the selection of the organic substances and two lines of incenerator for what remains of refuse.The furnace are situated in the center of Pistoia and are definitively shut down because unsuitable to the environment. Programma(i) ENG-ENDEMO C - Programme (EEC) of demonstration projects and industrial pilot projects (EEC) in the energy field, 1985-1989 Argomento(i) 1.1 - COMPOST AND FERTILIZERS PRODUCTION Invito a presentare proposte Data not available Meccanismo di finanziamento DEM - Demonstration contracts Coordinatore Ecologia SpA Contributo UE Nessun dato Indirizzo Viale Isonzo 14/1 20135 Milano Italia Mostra sulla mappa Costo totale Nessun dato
