Cel To attain heat saving in a foundry which produces cast iron castings using 2 cupola furnaces connected with a gas recuperator. The energy available for recovery is that contained in the exhaust fumes from the furnaces as well as from the recuperator. The heat recovered is then redistributed by means of a suitable heat exchanger to several civil and industrial users, previously supplied by local power plants.The trial period lasted until November 1983 and included the measurement of the parameters necessary to calculate the energy and mass balances. The temperature of the fumes taken from the cupola furnaces were some 20-30 C lower than the expected 80 C. This was due to a better than expected fume suction rate in the recuperator. The average temperatures of the fumes at the entry and exit of the exchanger were respectively 650 C to 400 C. The mean gas flow at the exit of the recuperator in full production days reach approximately 9,000 Nm3 per hour, but dropped to 7,500 Nm3 for 13-hour production days. In the first case a thermal power of approximately 730,000 kcal per hour, equivalent to 200 TOE per year is available, in the second 610,000 kcal per hour, equivalent to 165 TOE per year, is available. If the heat lost in the diathermic oil circuit is subtracted, in the two cases respectively 188 TOE per year and 155 TOE per year remain available. As the paint workshop utilises the available energy for 10 hours per day during 4.5 working days and not 5 working days, the above figures are to be multiplied by 0.9 to obtain the real energy usage of the paint workshop. From the tests performed, comparing the methane consumption of the paint workshop with the heat exchanger both inserted and disconnected, a saving of 630 m3 of methane is obtained, equivalent to approximatelly 100 TOE per year. Taking into account the work cycles of the different sections of the factory, 80-90 TOE per year for 7,500 Nm3 per hour of fumes flow can be recovered from the fumes cooled downstream of the diathermic oil exchanger. The overall energy saving attained thanks to the above modifications is of the order of 200 TOE per year.The plant consists of 2 cupola furnaces with a capacity of 8 tonnes per hour of cast iron and a recuperator that preheats the air feeding the furnace blowers from its ambient temperature up to 450-500 C. The recuperator uses as fuel the CO (carbon monoxyde) produced in the cupola furnaces. The blower feeds 6,000 Nm3 of air at ambient temperature and under a H20 pressure of 1,500 mm to the recuperator in counterflow to the furnace's combustion gas produced by a methane burner and properly mixed with air. The recuperator is equipped with a water scrubber for fumes and dust damping. The maximum flow of the exhaust fumes from the recuperator is 11,000 Nm3 per hour at 800 C average temperature.The heat recovered is going to 4 users :1) the paint workshop of a wood working machine manufacturer. The energy needed is 300,000 kcal per hour at 60-70 C for the pickling tank, 480,000 kcal per hour at 18-20 C for the painting cabin, 300,000 kcal per hour at 90 C for the drying furnace.2) shower baths requiring 800,000 kcal per hour at 90 C.3) several low temperature end users.4) an air-heating system for a maintenance workshop, which previously used a 500,000 kcal/hour boiler producing 45 C warm air for mixing with ambient air to achieve 18-20 C average.The energy is recovered as follows : a diathermic oil heat exchanger is inserted on the inlet manifold of the recuperator. Its operating conditions are :- hot fumes flow 11,000 Nm3 per hour- inlet fumes temperature 670 C- outlet fumes temperature 320 C- utilisable horsepower 1,207,500 kcal per hour.Diathermic oils serve the users number 1 and 2 while the residual energy is assigned to the user number 3. The fumes leaving the diathermic oil heat exchanger at 320 C are mixed with the fumes at 80 C leaving the cupola. Thus a fumes flow of 22,000 Nm3 per hour at 200 C is available. The fumes enter a filter at a maximum 120 C temperature; the operating temperature is nearly 110 C and is reached by heat exchange between fumes and air, achieved by two blowers. The available thermal power is approximately 620,000 kcal per hour. The air flow from blowers can serve the user number 4. Program(-y) ENG-ENALT 1C - Programme (EEC) of financial support for projects to exploit alternative energy sources, 1979-1984 Temat(-y) 1.6 - INDUSTRY Zaproszenie do składania wniosków Data not available System finansowania DEM - Demonstration contracts Koordynator Consorzio Fonderie Scm SpA Wkład UE Brak danych Adres Via Emilia 71 47037 Rimini Włochy Zobacz na mapie Koszt całkowity Brak danych
