(194c) The Cost of Incomplete Cleaning

The fouling of heat exchangers has a well understood impact on operating efficiency as it can increase energy consumption, emissions, maintenance costs, and above all may limit throughput or product quality. Operators expend significant effort and cost to address fouling through maintenance and turnaround cleaning. In a program of trials, it has been demonstrated that the traditional methods commonly employed often fail to clean heat exchangers back to “clean performance” levels. What is the cost of the fouling that is left behind by incomplete cleaning? The benefits of a thorough cleaning and how different cleaning techniques affect these benefits will be discussed in this presentation, along with a system for accounting for all cleaning and fouling costs.

It is often impossible to assess, on the washpad, whether a heat exchanger is completely clean, and because different cleaning techniques have varying degrees of effectiveness and cost, we frequently inadvertently settle for a partial cleaning. Before choosing a cleaning technique, it is important to take into consideration all cleaning-related expenses as well as the impact of incomplete cleaning. We will examine the economics of chemical cleaning, hydroblasting, and ultrasonic cleaning as they apply to the case of a crude preheat exchanger where fouling results in all the effects mentioned. We will also give a brief overview of the various cleaning methods, including how they are applied, how expenses are affected, and when they should be done.