FIELD: steam generation.
SUBSTANCE: invention relates to evaporator apparatuses. Heat exchanger apparatuses for receiving water from steam drum (1) and providing steam and heated unevaporated liquid water to the steam drum include first evaporator (EVAP-1) and second evaporator (EVAP-2). First evaporator can receive water from a steam drum via first feed conduit (9) and the second evaporator can receive water from second feed conduit (11). Both evaporators can output heated fluid to the steam drum via combined evaporator output conduit (13). Each first evaporator passageway (14) only makes a single pass through gas duct (15) having heated gas flow (7) passing therethrough, while each second evaporator passageways (24) can make one or more passes through the gas duct for transferring heat from the gas to the fluid within the evaporators. Portion of the first feed conduit can also have a pre-specified volume a pre-specified height below first inlet (10).
EFFECT: technical result is preventing a reverse flow of steam to the drum and hydraulic impact.
18 cl, 3 dwg
