How to Effectively and Efficiently Clean Heat Exchangers

Introduction

Whether onsite or offsite, the methods for cleaning shell and tube heat exchangers can vary. Refining and petrochemical operators will agree that high standards must be employed with each method. Choosing the right method can make the difference between smooth operations and unforeseen equipment shutdowns.

This three-part series explores the various methods, benefits, challenges and solutions to efficiently and effectively cleaning heat exchangers, both onsite and offsite. In Part I, we will discuss the importance and key benefits of optimal cleaning and whether heat exchangers should be cleaned onsite or offsite.

Importance of Cleaning

Over the operational lifespan of most heat-exchange equipment, various chemicals or solids (known as foulants) will “fall out” or be extracted from feedstock solutions due to changes in temperature. These solids can adhere to the walls of the equipment’s tubes, pipes, and inside valves and flanges, causing the equipment to foul. Over time these foulants will compound, dramatically changing the flow-rates of fluid through the exchanger, causing a loss of efficiency and functionality, affecting throughput and heat transfer, and increasing the risk of unsafe operations.

To avoid such results, operators must periodically remove or “purge” the buildup of chemicals and residue that coat the tubes before the contaminants reduce or stop heat transfer from coils to water. Most methods are referred to as “descaling” the tubes, because the expelled sediment or contaminants appear as little flakes resembling fish scales.