Paper Title
Analysis of Prevention of Crack and Corrosion Precipitation through the Application of Ozonation Techniques on Water Spray Filling Close System Cooling Tower

Abstract
A cooling tower is a unit that is used for the disposal process in a cooling system. Thermal effectiveness is a very important variable to determine the performance of the cooling tower. The emergence of corrosion, moss, and crustal precipitation can inhibit heat transfer so that it can disrupt the level of thermal effectiveness of the cooling tower. Not only does it reduce thermal effectiveness, but it can also damage the cooling tower. This study aims to determine the effect of ozonation on these inhibiting factors. This ozonation process is expected to reduce the growth of these factors. The method used is with cooling water from the basin circulated with a new system. In the new system water from the basin will be injected with, then the water will return to the basin. Furthermore, water samples will be tested in the laboratory using the AAS, Titrimetric, Gravimetric, Spectrophotometric method to determine water quality. Data obtained from the laboratory are Ph, Electrical Conductivity, TDS, Ca, Alkalinity, Mg, Na, Cl. The data is then entered into the calculation using the Practical Ozone Scaling Index and Langelier Saturation Index method to determine circulating water quality. The results obtained from this study show that the application of ozone can improve water quality because TDS and EC in the cycle water used decrease. The amount of safe water cycle concentration is also increased from 2 cycles to 4 cycles. Keywords - Cooling Towers Closed Systems, Ozone, Corrosion, Precipitation