ABSTRACT
The precipitation of minerals onto the walls of water-handling equipment is a serious problem encountered in many industrial processes due to downtime required to clean equipment and the cost of possible loss of product purity [1-4]. These deposits are formed from salts that are dissolved in the process feed water. During the process, the process water becomes supersaturated with these salts that then precipitate out onto equipment walls. Supersaturation of process water usually arises from an increase in temperature or from an accumulation of dissolved salts in a recycling stream. These deposits, which are called scale, cause a reduction in heat transfer rates in equipments such as boilers, evaporators, heat exchangers, and distillation units [5-7]. The problem of scale formation leads to partial or even total blockage of water ow and is the cause of boiler cracking and boiler explosions. The economic loss due to scaling is one of the biggest problems in all industries dealing with heat transfer equipment. It was reported that the deleterious effects of scaling, which were energy losses due to the reduction of system performance, increased capital costs for excess surface area in heat exchangers and unscheduled maintenance due to a severely fouled condition [8]. In a recirculating cooling system, concentration of mineral ions in water continuously increases due to water evaporation, creating conditions for severe fouling.
