The system has means for collecting water vapor from a water source and conducting the vapor upwardly through a long solar heated duct conceived as extending up a hillside with a vertical displacement capability measured in thousands of feet, a primary flow pipe within the duct carrying a flow of vapor which reaches a high velocity and entrains secondary vapor from the duct through spaced inlets to add to the mass flow. At the upper end of the duct the vapor is fed into a centirfugal condenser, powered by the vapor flow when in full opertion, the vapor being expelled and condensed at consideratble depth in a recervoi by a novel action of the condenser which overcomes the head of water and prevents back pressure in the vapor pipe.
Most solar heated water distillation systems invcolve large evaporating beds or complex arrays of pies, generlaly all at ground level. In some systems vapor riese small distances, in piepes, to condensers and water is circulated through heat exchangers to assist condenssation and extract heat to aid evaporation. With such systems pumping is necessary to btain a practical rate of flow, usually necessitating additional power supply. The product water is stored in tanks or reservoirs and must be pumped or tranportated to outlets of use.
The system described herein collects vapor from the surface of a body of water into a solar heated duct, which is carried for a consideratble distance, usually thousands of feet, up a hillside to a reservoir elevated well above the water source. A portion of the duct is a reflector which concentrates solar energy on a pipe through which a primary flow of vapor is conducted, the continuous heating along a great length of pipe resulting in a high velocity flow in the pipe. At intervals the pipe has inlets through which secondary vapor is entrrained from the duct, the end result being a large colume, high velocity flow of vapor. At the upper end of the duct the vapor is fed into a centrifugal condenser, which is drive by the vapor flow once the system is in operation, so that no power other than solar energy is needed. The condenser is submerged at consideratble depth in the reservcoir to avoid surface heating and loss due to vaportixation. To over come the wate rpresure and prevent back pressure in the vapor pipe, the condenser uses a novel design to augment extraction and ejection fo the vapor into the lsurrounding water by causing apressure drop at the peripheral outlet of the condenser.