Background. One of the major factors influencing service life of vaporizing pipes of boilers is the state of their internal heating surfaces. To prevent vaporizing pipes from damage, these surfaces are periodically chemically cleaned of deposits. Now a number of new washing reagents are offered for such cleanings. At the same time, there are not enough data on the influence of the washing solution composition, temperature and duration of cleaning on technical efficiency of cleanings with these washing reagents, on the speed and completeness of deposit removal. All this makes it urgent to study the rate of cleaning of wall tubes from deposits by using different cleaning reagents under different conditions.
Materials and methods. The samples of vaporizing pipes of steam boilers were studied by the method of etching in the conditions of heating and without it. Inhibited hydrochloric acid, Antirzhavin, Deskam, Auge Pro Ac were used for chemical cleaning. The specific contamination and the chemical composition of deposits were determined according to the requirements of SO 34.37.306-2001.
Results. In the course of the laboratory study, we obtained the dependences of the rate of removing lumpy and uniform deposits, as well as the metal corrosion rate of the evaporating pipes on the type of cleaning reagent solution, cleaning temperature and duration. It has been established that the rate of cleaning of pipe samples from uniform and lumpy deposits in acid solutions of the investigated reagents is 15–30 % greater than in a solution of inhibited hydrochloric acid.
Conclusions. The obtained experimental data can be used for choosing the technology of acid cleaning to reduce its duration, at the same time ensuring the smallest residual specific contamination of the metal surface under conditions most suitable for industrial facilities.