Steam separator to reduce carryunder

In a steam generator comprising a steam drum enclosing a plenum, means disposed within the plenum of the steam drum for separating steam from liquid water, the plenum for collecting liquid water and steam separated by the separation means, the liquid water thereby forming a water level in the plenum above which the separated steam occupies the plenum during operation of the steam generator, means for transferring heat to water to create a mixture of steam and water, means for delivering the mixture to the separation means, and means for returning the separated liquid water along a flow path from the separation means back to the heat-transfer means, the return means having an inlet opening into the plenum at a location below the water level therein, the improvement comprising:

• a bubble rake disposed within the plenum external to the separation means at a location in the flow path below the water level and near the inlet of the return means, the bubble rake having a surface that defines a channel opening generally down and in the direction of the flow path and extending longitudinally at an angle with the horizontal, the channel thereby having a high end, the buoyancy of steam entering the channel thereby causing it to be trapped in the channel and migrate to the high end of the channel, the channel forming an opening at its high end for releasing the trapped steam, whereby steam remaining in the separated water is removed therefrom and released at a higher level, the amount of steam returned to the heat-transfer means thereby being reduced.