Effectively and Efficiently Cleaning Heat Exchangers — Part 3

Introduction

Heat exchangers operating in refineries or petrochemical plants must be thoroughly cleaned and inspected throughout their operational lifetime to ensure safe and efficient operations. These routine procedures are necessary because the equipment comes into contact with various feedstocks, process chemicals, and cooling water that will develop exchanger foulants over time.

These foulants can adhere to the walls of the equipment’s tubes and pipes, as well as inside various valves and flanges, thus causing the exchanger to reduce heat transfer. Over time, these foulants will be compounded, which dramatically changes the flow rates of fluid through the exchanger and causes a loss of efficiency, and increases the risk of unsafe operations. Moreover, deposits from fouling can cause hot-spots and corrosion conditions that lead to premature equipment failure.

To avoid such results, operators must periodically remove the buildup of foulants that coat the tubes before they reduce and limit operational efficiencies. This procedure must be done carefully to avoid damage to equipment components, and more importantly, to prevent injury to cleaning personnel.

This article is Part III of a three-part series that explores the various methods, benefits, challenges, solutions and safety methods to safely, efficiently, and effectively clean heat exchangers, both on and offsite.

In Part I, published in the January/February 2015 issue of Inspectioneering Journal, we discussed the importance and various benefits of optimal cleaning, and whether heat exchangers should be cleaned on or offsite. In Part II, published in the September/October 2015 issue, we discussed several different methods of cleaning heat exchangers. Now, in Part III, we will address specific safety issues related to proper heat exchanger cleaning.

Hands-Free Automated Equipment

Third-party service providers can use automated equipment for both on and offsite cleaning to reduce the safety and environmental risks associated with high-pressure cleaning. Manual cleaning methods dramatically increase the likelihood of high-pressure injuries and chemical exposures, particularly for the operator. Participating personnel become vulnerable to high-cut hazards, operator fatigue due to the added discomfort of wearing PPE (Personal Protective Equipment), and the risks that come with holding high-pressure handheld equipment for extended periods of time.