Regular/periodic cleaning of heat exchanging equipment is the major factor for plant economic efficiency increasing and it also increases the service life of cleaned equipment.
ALVIGO Group of Companies provides services for cleaning of operating heat exchanging equipment of ammonia – methanol plants, as well as nitric acid, prussic acid and hydroxylamine sulfate from sludge. Constantly improving the technology of works performance, ALVIGO is the leader in the market of services for chemical plants equipment cleaning with the aim of metal recovery, containing platinum group metals (PGM).
The following methods are used to clean process equipment:
- Mechanical method
Depending on design features of equipment, required cleaning, ALVIGO Group of Companies can perform cleaning by mechanical method. Mechanical cleaning is successfully used in gas-tube type boilers. Cleaning of storage tanks bottoms, inner sides of gas ducts and lining is also performed using mechanical cleaning.
Such type of cleaning is performed with the help of milling cutter which is a special cleaning tool skimming off only thick layer of rust and scale, containing practically all PGM located in equipment. The material of cleaned equipment is not affected.
- Chemical method
To recover PGM, we also successfully use the method of chemical cleaning of process equipment by inhibited aqueous solutions of sulfuric acid and phosphoric acid. This cleaning method is the only one way to clean vessels in heat exchanging equipment, where nitrous gas passes to shell side. For aqueous solutions of sulfuric acid such cleaning is conducted in optimal mode considering concentrations, temperature and time, required for cleaning process.
The technology of nondestructive/destructive physical-chemical cleaning is based on the process of acid etching of cleaned surfaces. Conveniently it can be separated into 4 stages:
- Preliminary mechanical cleaning (removal of equipment cleaned and its treating by physical-mechanical methods for sludge extraction from available surface).
- Acid etching (equipment is located into sulfuric acid basin, reacting with surface layer of rust and scale, sludge is settled on the bottom of basin in the form of settlings.)
- Washing by water (sludge residues is washed by water. Performed above basin).
- Solutions neutralization and sludge collection (received sludge is dried and homogenized.)
- Hydrodynamic method
Одной из наиболее востребованных и эффективной современных технологий с точки зрения экономики и экологии является гидродинамическая очистка. Очистка происходит внутри котла-утилизатора.
One of the most popular and effective modern technologies from the standpoint of economic and ecology is the hydrodynamic cleaning. This cleaning is performed inside waste heat boiler. Such method is as follows: contaminated surfaces are treated by water under pressure 2500 bar. Washing the tube of heat exchanger is performed by water supply through flexible hose with special cap on the end. For more effectiveness different modifications caps are used, with the possibility to control the required pressure and angle of spray distribution.
Advantages of hydrodynamic cleaning:
- high effectiveness: collection of 90 – 99% of PGM deposits;
- environmental safety;
- guarantee of customer equipment protection;
- specialized complex equipment;
- loss free of PGM in the form of dust.
Usage the different cleaning methods as well as reagents of proprietary developments finally ensures high degree of cleaning and complete guarantee to preserve the residual operational life of cleaned equipment.
To conduct process equipment cleaning works ALVIGO GC designed and built the unique mobile production complexes (MPC), which no one of competitors has anything similar to.
We also perform:
Primary treatment of sludge, received during equipment cleaning, as follows: preliminary sorting from foreign bodies, drying, fine grinding, homogenizing, packing and so on.
- keeping of residual operational life of cleaned equipment. To confirm keeping, in standard, hydro tests are conducted before and after cleaning.
- keeping of boiler operation process parameters.
- it is possible, but not for sure, that some improvements of working conditions can happen. In particular, steam generation increasing and gas temperature at boiler outlet reduction.
Inquiry for vessel inspection, preliminary estimation of PGM collection and preparation of TCP for cleaning works conducting you can send us by email.
Responsible person for cooperation
Chief Specialist of Department of technological cleaning of equipment of JSC GIAP
+7 495 916 6094
+7 495 916 6810