摘要 |
A draft control plate, which automatically opens or closes to provide efficient draft conditions in a furnace, is provided with both horizontal and vertical counterbalance devices which respectively permit adjustment of the initial position of the plate and the sensitivity of its movements. Initially, the plate is partially open where it remains while the furnace is operating under normal conditions. It is then capable of opening or closing in response to changes in the pressure differential across it. Preferably, the plate is horizontally mounted in an auxiliary flue channel which is adjacent to and in connection with the main flue of the furnace. |