Descaling methods and its importance

Descaling methods are one of the most important measures that must be done through different methods after using some equipment. In general, descaling is divided into two methods, these two methods include preventing the formation of sediment and the other is removing the formed sediment layers. There are two ways to remove sediment. You can tolerate the build-up until it becomes unbearable, then remove it once and for all. Another way is to prevent the formation of sediment. All preventive methods are more expensive than descaling, but have higher efficiency.

Deposition Removal Methods

Many methods are used to clean heat exchangers, including mechanical and chemical washing. Normally, the types of descaling methods include the following:

✔️ chemical descaling
✔️ mechanical descaling

Chemical deposition

In heat exchangers, when determining defects or reducing heat transfer, after the exchanger is out of service, necessary chemical tests based on the process conditions should be performed on the samples in the sediments. In this case, the type of sediments including sediment caused by the process fluid or due to corrosion are determined. After determining the type of deposit, heat exchangers are washed through unique equipment. Usually, these equipments are created from several tanks with special anti-corrosion coatings and are filled with chemicals according to the type of washing process and connected to each other with pipes.

To establish flow, pumps are selected that are connected with pipes compatible with the desired generator and rotate the detergent. Many materials and solutions such as alkalis, acids, corrosion inhibitors, wetting solutions and organic solvents are used in industrial chemical washing. The type of solvent is selected according to the type of metal and alloy, the solubility of the deposit and in addition to its economic cost.

Mechanical sedimentation

Mechanical methods can be mentioned among other descaling methods. The mechanical method is mostly used to clean the heat exchangers. Using high pressure water is one of the common choices in this case. Since the water jet slowly cleans the pipes; Therefore, this method is time consuming. The noteworthy point is that in this method, cleaning is done slowly and with utmost precision, because increasing the speed causes destruction of tubes or tube sheets.

In most cases, these damages are identified after the converter is serviced again. Plastic cleaners are the most important tools for mechanical descaling. These types of cleaners are more useful if the converter contains soft deposits. You can use cleaning brushes to separate soft deposits. These tools are more effective for cleaning biological sediments.