Countercurrent heat exchanger

Recently I've been thinking about a cylindrical machine tilted at about 45 degrees which is all one piece, as described in the last post. It feeds hot water in at top center, and the water flows through and finally out at middle outside. There are two heat exchangers, both water to air, instead of one air to air. This avoids the need for high pressure piping because the high pressure air stays in deep water where its pressure equals the ambient.  Near the surface, hot low pressure air is cooled by cold water, and at the maximum depth, cold high pressure air is warmed by hot water.

Last post I asked what's the difference between the helix and a countercurrent heat exchanger? The purpose of the low pressure exchanger is to be sure the air is as cold as possible before any work is expended compressing it. If the exchanger has flexible walls, this means the air has to be at constant depth. The heat exchanger looks like a conical hat on the cylinder. With the cylinder axis at 45 degrees, the cone has a right angle at apex. The highest surface of the cone is horizontal. As the cylinder rotates about its axis, that surface will be vertical after 1/2 turn. The air stays under the horizontal part.

The cone has two parallel surfaces, top and bottom. (Really two cones). The space between is filled mostly with water, and an air pocket at minimum depth. The top surface has a spiral wall which leads the air toward the axis as the rotor turns. Since the air pocket is horizontal (45 degree cone tilted at 45 degrees), the air stays at constant pressure as it moves toward the axis.  The water flow needs to be in the opposite direction, from axis toward the outer edge.  There will be a second pair of surfaces in which the air moves away from the axis and the water moves toward the axis. 

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