| 摘要 |
A subsidiary stage heat exchanger 1 and a method of recovering heat in a subsidiary stage of a boiler/water heater comprises a vessel 2 to receive and reserve flue gas condensate 10 from a primary stage condensing heat exchanger, a flue gas conduit 16 having an outlet 22 disposed below a level of the condensate 10 reserved in the vessel 2 and in use communicating flue gas 14 from the primary stage heat exchanger into the condensate 10, and a heat transfer means 26 provided within the vessel 2 and arranged to transfer heat from the condensate 10 into the heat transfer means 26. Heat transfer means 26 may be disposed below the condensate level 10 and may comprise of a spiral conduit 26 with heat transfer surface communicating sanitary water, central heating water or both. Vessel 2 may comprise of a lower portion 4 for collecting the condensate 10 and an upper portion 6 provided with a vent 8 to atmosphere for the flue gas 24 passing through the condensate 10 and a separate conduit 20 that may supply the condensate 10. Drain 12 maintains the level of the condensate 10. A mesh 28 may be provided to reduce the formation of large bubbles and hence reduce noise. Advantageously, the condensate 10 may remove pollutants present in the flue gas 14 by scrubbing, reduce pluming effects witnessed. The boiler may be condensing boiler. |
