摘要 |
<p>An evaporator includes two sections - a once-through section (22) and a circulation section (24), both of which include tubes (34, 44) located in the flow of hot gases. Heated water flows through the tubes (34) of the once-through section at a rate sufficient to maintain the interiors of its tubes fully wetted while enabling steam to develop in that water. The circulation section includes a drum (42) that is connected to the tubes (44) of that section such that water from the drum circulates through the tubes and then back to the drum, with the circulation being such that the water in the tubes of the circulation section keeps the tubes fully wetted while steam develops in that water. The water from the tubes of the once-through section discharges into the drum, as does the water circulating back from the tubes of the circulation section.</p> |