Thermocompression-type apparatus for desalting saline water

In a thermocompression desalting apparatus for saline water comprising:

• an evaporator section including a heating chamber and a bundle of evaporator tubes crossing the chamber;
• means for circulating saline water through the tubes in the bundle, the said means including a separating chamber in which the steam produced in the evaporator section is separated from the non-evaporated saline water;
• a compressor arranged to suck steam from the separating chamber and to deliver it at an increased pressure to the heating chamber as heating fluid for the evaporator tubes;
• and means for recovering the condensate from the heating chamber;
• the improvement comprising:
• the said evaporator tubes extending vertically above the separating chamber and having their lower ends opening into the latter through a lower header plate;
• the upper ends of the evaporator tubes extending through an upper header plate into a plenum chamber overlying the latter, said plenum chamber being included in said circulating means and being arranged to provide a pool of said water submerging the upper ends of the evaporator tubes;
• each of said upper ends having means therein arranged to receive saline water from the said pool and to discharge it in the form of a falling film on the inner surface of its respective evaporator tube, the said evaporator section comprising a vertical cylindrical casing which encloses the plenum chamber and the heating chamber and is closed at its lower end by said lower header plate;
• a base section supporting the evaporator section comprising a horizontal cylindrical closed-ended vessel having a pair of inner impervious vertical partitions therein;
• the said partitions defining in the vessel a collecting chamber at one end of the vessel, a conditioning chamber at the opposite end of the vessel, and the said separating chamber extending between the partitions through a major part of the length of the vessel;
• an upwardly directed mouth in a top zone of the wall of the vessel in the region of the separating chamber;
• the casing of the evaporator section sealingly seated in the said mouth and having its bottom part protruding through the said mouth into the separating chamber;
• a downcomer tube opening at its upper end through the lower header plate into the heating chamber and at its lower end into the collecting chamber through the respective partition thereby to discharge into the collecting chamber the condensate from the upper face of the lower header plate;
• the said compressor being mounted on a top wall portion of the said vessel above the separating chamber and having its intake communicating with the latter chamber through an aperture in the said top wall portion;
• a tubular elbow connecting the delivery side of the compressor to an upper portion of the heating chamber;
• a conduit supplying saline water to be desalted opening into the conditioning chamber;
• a further conduit connecting a top portion of the conditioning chamber to the said vacuum source;
• and pump means connecting the bottom region of both the separating chamber and conditioning chamber to the plenum chamber to thereby deliver to the latter the saline water to be evaporated in the evaporator tubes.