The induced draft fan (ID fan) generates a depression inside the rotary kiln, secondary combustionchamber, waste heat boiler, gas cooling tower and baghouse filter to extract the flue gas generatedby waste combustion without risk of leakage to the atmosphere, and pushes it through the last stagesof wet treatment before release to the atmosphere via the stack.The fan shall be of the centrifugal type. It shall be able to operate over the complete operation rangeof the incineration line, from minimum to maximum case, taking into account the pressure dropupstream and downstream. Induced draft power is adjusted by acting on the frequency of the fanmotor in order to maintain a slight depression (adjustable -2 to -5 mbarg) at the top of the SCC.The fan and motor shall be designed and installed to run without any undue vibration and the noiselevel shall not exceed that stated in the relevant section. The electric motor shall comply with therequirements of the specification and will be fully compatible with the VSD.The rotary speed of the ID fan shall not exceed 1500 rpm. Its overall efficiency (taking into accountelectrical and mechanical losses) shall not be lower than 70%.The fans shall incorporate all features necessary to ensure reliability in operation and ease ofmaintenance.The required differential pressure of the ID fan indicated in the datasheet is based on assumptionsfor the pressure drop in the different equipment of the flue gas treatment package. The Supplier isresponsible to adjust the actual ID fan performance based on actual pressure drop of the equipmentwithin its scope of supply.ID fan is one of the most critical elements of the incineration line, for which high performance andreliability is requested. The Supplier of the ID fan shall be a well-known brand with proven successfulreferences. The proposed Supplier of the ID fan will be subject to validation by the Employer.The performance curves of the fan will be tested in the workshop and submitted to the Owner’sapproval before delivery.