Heat-Treated Titanium Balls for the Mitigation of Mineral Fouling in Heat Exchangers

Abstract

The present study investigated the feasibility of a physical water treatment (PWT) concept using heat-treated titanium balls for the mitigation of mineral fouling in heat exchangers. A concentric tube heat exchanger in a counter-flow set-up served as the test section, where three different velocities (i.e., 0.3, 0.5, 0.8 m/s) were used for the fouling tests. The results showed that for the PWT cases fouling resistances were 24-30% lower than those for the untreated cases, depending on the flow velocity and the electrical conductivity of water. The SEM photographs of the fouling deposits in the PWT cases revealed a soft form of scale that could easily be removed by the shear forces produced by the flow in the heat exchanger. Furthermore, the PWT case produced more particles in bulk water by approximately 35% than the untreated case, supporting the bulk precipitation hypothesis for the PWT.

Physical water treatment using RF electric fields for the mitigation of CaCO3 fouling in cooling water

“…Aragonite has a specific gravity of 2.95 while calcite has 2.71. The orthorhombicshaped and denser aragonite tends to be more adherent to heat transfer surfaces than the hexagonal-shaped calcite [6,16]. The chemical reaction for the precipitation of CaCO 3 is found in the literature [3,4,16].…”

“…Numerous studies have been reported for the effectiveness of the use of permanent magnets [3,4,8,11,[17][18][19][20], solenoid coils [3,4,8,[21][22][23][24], catalytic materials like copper, zinc [25,26], and titanium [16], and ultrasounds [10]. In this paper, RF (radio frequency) electric fields generated between two graphite electrode plates directly in water were used to mitigate mineral fouling in a doublepipe heat exchanger.…”

Effect of Magnesium Ion Concentration on the Scale Inhibition of Heat Exchanger in Circulating Cooling Water under Alternating Electric Field

“…The problems on production safety and equipment maintenance caused by calcium carbonate scale have becoming increasingly serious. Calcium carbonate is an inversely soluble salt [1], that is, its solubility decreases with increasing temperature. Calcium and carbonate ions in the circulating cooling water combine to form calcium carbonate scale and are deposited on the surface of heat exchangers.…”

“…Scale inhibition methods are mainly classified into chemical and physical techniques. The former generally has disadvantages, such as high cost and secondary pollution to the environment [2,6], whereas the latter is economic and environmentally friendly [1,2,6,[8][9][10][11]. Hence, physical water treatments may replace chemical methods.…”

Experimental Study on Magnetic Induction Properties of PVC Pipe in Electronic Anti-Fouling Technology

“…Traditional physical descaling methods such as scraping, sand blasting, and metal or nylon brushing incur downtime and repair costs [9]. For these reasons, new physical methods such as electronic anti-fouling technology, catalytic material, and sudden pressure change have recently been developed [5][6][7].…”