Patent ID: 7571554
Filing Date: 2009-08-11
Classification: F26B,Y02P

Abstract:
1. A ventilation system for controlling the drying conditions in at least first and second drying chambers, the system comprising: a heat exchanger for pre-heating make-up air with exhaust air from the drying chambers; a main supply conduit in fluid communication with the heat exchanger and having at least first and second branch supply conduits for supplying pre-heated make-up air from the heat exchanger to the first and second drying chambers, respectively; a main exhaust conduit in fluid communication with the heat exchanger and having at least first and second branch exhaust conduits in fluid communication with the first and second drying chambers, respectively, such that exhaust air from the first and second drying chambers can flow into the main exhaust conduit via the first and second branch exhaust conduits, respectively; a first air mover configured to induce make-up air from atmosphere to flow through the heat exchanger, the main supply conduit, the first and second branch supply conduits, and into the drying chambers; a second air mover configured to induce exhaust air from the drying chambers to flow through the first and second branch exhaust conduits, the main exhaust conduit, the heat exchanger and then to the atmosphere; and a pressure controller operatively connected to the first and second air movers and configured to automatically vary the speed of the first and second air movers to maintain substantially constant predetermined pressures of the make-up air traveling from the heat exchanger through the main supply conduit into the first and second drying chambers, and the exhaust air traveling from the first and second drying chambers through the main exhaust conduit to the heat exchanger; wherein the pressure controller comprises: a first pressure transducer that is operable to measure the pressure in the main supply conduit; and a second pressure transducer that is operable to measure the pressure in the main exhaust conduit; the pressure controller being operable to vary the speed of the first and second air movers based on the measured pressures to maintain substantially the predetermined pressures in the main supply conduit and the main exhaust conduit.