Design Development for Enhanced Desalinate Tubing Test Apparatus

The aims of current research programme are itemised as to design a research rig simulates the desalination heat exchange process, assess the feasibility of enhanced heat transfer mechanisms in MSF plant, examining actual brine water that typifies real process conditions, study the influence of flow speeds on fouling resistance and the effect of tube diameter on its behaviour. The first apparatus designed is test-Rig (A), consists mainly of a cubic box simulating the steam condenser. Six horizontally tube are mounted, through which the coolant solution is flowing and the vapour from a boiler source is condensed outside the tubes, but inside the box. These tubes are aluminium-brass made. The test rig is instrumented in such a way that temperature at all important points in the apparatus can be monitored, as well as the flow rate of all the fluid streams. The thermocouples are inserted in the important points. Experimental results are discussed for both smooth and corrugated tube, when applying fresh and real brine water on different flow speeds. This apparatus has to be redesigned, since buckling, as well as cracks developed in the plixcy-glass box's wall due to thermal stresses, existence of mutual heat transfer between tested tubes, existence of non-uniform distribution of steam through-out the box, venting valves need to be added to water circulation loop, modification of pumping system through automation and redesign a water reservoir to keep the inlet temperature to the rig constant. The problems revealed above with using test-rig A, are given a careful consideration in assessment and assembly of test-rig (B). The modified set-up facilities included a new configured design for the steam condenser, equipped in such a way to minimize mentioned obstacles, dismantling faced problems associated with; circulated pumps, boiler, flow meters and its place of fitting, careful identifying the tested tube characteristics, a wise differentiation between properties of brine and fresh water, a creation of uniform steam temperature distribution inside the rig, preventing of two phase flow creation and simulating the actual circumstances in real desalination platform. The data collection system previously described is used in conjunction with the test rig (B). Use is made of two horizontally mounted tubes through which the coolant solution is flowing. Corrugated and smooth tubes are examined at a time to unify the tested conditions on both. A three different coolant flow velocity of 0.1, 0.1645 and 0.2398 m/s are examined. The study is carried-out for two different coolants, fresh and brine water. The effect of fouling of actual Brine water with the avoidance of using artificial fouling, as well as the effect of used corrugated tube with its chosen comprehended roughen enhancement, effect of changing tube diameters and Reynolds numbers on experimental data results are provided in the form of: overall heat transfer coefficient vs. time for both tubes, the rate of condensed water mass out of corrugated tube with respect to the rate of condensed water mass out of smooth tube. The fouling resistance vs. time, the overall enhancement ratio vs. time, the cleanliness factor vs. time and the overall fouling resistance ratio vs. time. Chosen applications are included in this paper.