YYL（YYW）series of organic heat transfer oil boiler is packaged forced circulation oil/gas fired boiler. This series of boiler body has a compact heating surface, consisting of inner,middle and outer(or inner and outer)closely aligned round coils. Inner coils are radiation heating area and middle and outer coils serve the convection heating area with external surface of inner coil. Fuel burns and generates heat in the combustion chamber of inner coils. Most heat is absorbed by the radiation heating area and residue hot fume blows in the convection heating area for heat exchange. Finally low-temperature fume exhausts outside through the chimney via the fume outlet of boiler.
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