HOT-WATER WATER-TUBE BOILER Russian patent published in 2007 - IPC F24H1/00 

FIELD: heat-and-power engineering, particularly water heating equipment.

SUBSTANCE: boiler comprises furnace chamber and convective shaft arranged over the furnace chamber. The convective shaft is provided with heating surfaces located in upper part thereof and having cross-sections less than that of furnace chamber. The furnace chamber and convective shaft are made of gas-tight welded screens connected in accordance with four-way or two-way water circulation system. Lower part of convective chamber has normal section area equal to that of furnace chamber and has membrane heater formed of longitudinal ribbed pipes fluidly communicated with pipes of screens located in lower convective chamber part, which are formed as extensions of furnace chamber screens. Summary inner cross-section of membrane heater water pipes is 0.6-1.8 summary inner water flow sections of convective shaft screen pipes connected thereto. All convective heating surfaces are connected in counter-flow manner with descending water flow with respect to flue gas flow direction. Membrane heater located in lower part of convective shaft is connected in counter-flow or parallel flow manner.

EFFECT: increased energy efficiency.

3 cl, 7 dwg