Chemical Cleaning of Magnetite Deposits on the Flow Mini-Channels of a Printed Circuit Heat Exchanger in an EDTA-Based Solution

Abstract

The dissolution behavior of magnetite deposited on flow mini-channel surfaces within a printed circuit heat exchanger (PCHE) and the corrosion behavior of a STS 316L PCHE material were investigated in an ethylendiaminetetraacetic acid (EDTA)-based chemical cleaning solution at 93 °C. The fouling in the PCHE was simulated using a water-steam circulation loop system. Most of the magnetite deposits were rapidly dissolved in the early stage of the circulation chemical cleaning. An empirical equation for estimating the dissolution percentage was derived as a function of cleaning time. The PCHE material showed excellent corrosion resistance during the chemical cleaning tests. These results indicate the fouling layers in the PCHEs can be removed efficiently by the chemical cleaning process without concern about base metal corrosion.

Magnetite Deposition Behavior on Alloy 600 and Alloy 690 Tubes in Simulated PWR Secondary Water

“…Lee and Sung [30] showed that the corrosion rate of Alloy 600 was extremely low (maximum 2.3 mils) and was within the EPRI recommendation (<10 mils). Han et al [31] found that the corrosion rate of stainless steel 316L was very low in a 20% EDTA-based cleaning solution. In this work, except for Fe, the Cr and Ni elements were not detected in the ICP-OES results.…”

Mass/Heat Transfer Analogy Method in the Research on Convective Fluid Flow through a System of Long Square Mini-Channels

“…The condition of the inner surface of the mini-channel is important. Factors influencing the surface condition are roughness [8] and fouling [9]. Another issue is the type of heat transfer fluid: gas or liquid, single-phase or two-phase fluid flow [10][11][12][13][14].…”