Introduction
Capacity losses in plant-related equipment, such as heat exchangers, tanks and pipes, are usually caused by fouling. The nature and the type of fouling depend on the manufacturing and/or cooling process in which they occur.
The advantages of chemical in-line cleaning with respect to traditional high-pressure cleaning are the time saved and its effectiveness.
In-line cleaning implies that an installation is isolated with respect to the process, after which the cleaning equipment can be connected. By circulating the right chemicals, the fouling present is dissolved and expelled as the fluid leaves the installation. After neutralisation and post-purging, the installation is handed over clean for use. The chemicals to be used to dissolve the fouling depend on the nature and type of the foulant and the material from which the equipment is made. Because, for example, the heat exchanger does not require that its bundle is removed, considerable time can be saved compared with traditional cleaning methods. The high effectiveness of in-line chemical cleaning lies in the fact that the cleaning agent circulates in places where the production agents also circulate, including therefore in the middle of a bundle which high-pressure water has difficulty reaching.
Crude fouling
For years, cleaning crude fouling in installations has been a time-consuming and expensive business. Equipment fouled with crude fouling can be cleaned using in-line circulation. Besides removing the fouling, one can also remove H2S such that the installation can be immediately handed over gas-free. The resulting quantity of wastewater is substantially less than cleaning with conventional methods and easy to separate. By using the right chemicals, one can make the thickened crude pumpable again. These chemicals are not water but oilsoluble, which means that the waste, which is produced after filtering, can be returned to the process.