METHOD AND APPARATUS FOR REGULATING FLUID FLOWS IN PARALLEL-CONNECTED CONDUITS, E.G. IN FURNACE INSTALLATIONS HAVING AIR PRE-HEATERS AND BY-PASS CONDUITS

摘要

Method and Apparatus for Regulating Fluid Flows in Parallel-Connected Conduits (e.g. in Furnace Installations having Air Preheaters and By-pass Conduits) Fluid flow in parallel-connected conduits is regulated by sensing the pressures and/or temperatures at the junctions of the conduits, and regulating the supply of power to a fluid propelling means operable in one of the conduits in accordance with a signal with is representative of the sensed pressure drop and/or temperature drop between the junctions. In a furnace installation having an air preheater (14) in a duct (12) and a parallel-connected by-pass duct (18), the pressure difference and/or temperature difference between the junctions (19,20) of the ducts (12,18) is/are employed to generated a signal which regulates the supply of power to an induced draft fan (17) in the air preheater duct (12). The damper (21) normally provided in the by-pass duct (18) may be removed or set at its open position.