Chemical cleaning and steam blowing

We offer comprehensive services in the field of chemical cleaning, maintenance and steam blowing of devices such as: water and steam boilers, power boilers and steam pipelines, new and modernized power installations and others. We are authorized to perform repairs with chemical methods for devices subject to technical inspection No. CH-30-50/1-14.

The scope of our services includes:

Keeping the surface of technical devices clean is the basis for their correct operation. The presence of any contamination on the internal surfaces of devices is the cause of, among others:


Pre-operational chemical cleaning

Pre-operational chemical cleaning is used for newly started devices in order to remove from their internal surfaces impurities formed during production and assembly, such as: iron oxides, alkaline salts, scale and welding slag, waste from welding pearls and electrodes, welding scale, mill scale, post-production metallurgical scale, foundry soil, oils, greases, preservatives, sand, etc.

These contaminants, not removed before commencement of operation, cause serious disturbances in the operation of devices, including: circulating water contamination, stimulation of pitting corrosion and sediment formation, uneven flow of the heating medium, clogging of the smallest diameter pipes, failure to close the valves.

The pre-operational chemical cleaning process involves the action of chemical solutions on contaminated surfaces to convert the contaminants into soluble, dispersed or emulsified compounds in water and remove them from the system. Substances that do not dissolve in the reaction solutions are removed during the washing operation.

This process is also intended to create a protective passive layer that protects the internal surfaces against corrosion during the standstill between pre-operational chemical cleaning and steam blowing.

Alkaline boil out

The process is used, as in the case of pre-operational chemical cleaning, for new installations to remove contamination from the internal surfaces of production and assembly. The standard process is used for low pressure boilers, but it is also used for high pressure boilers when little contamination of internal surfaces is found.

The alkaline boil out is intended to clean the internal surfaces of boilers, pipelines and power equipment from contaminants from the period of production, storage and assembly, such as grease, grease, preservatives, and to a lesser extent from rust and mill scale.

Some of the contaminants are dissolved by a chemical reaction and the insoluble parts are removed from the system during the desludging and rinsing steps. The parameters of the alkaline boiling process, i.e. composition, concentration of chemicals, temperature, pressure and time depend on the degree of contamination and the type of boiler.

Thorough cleaning of internal surfaces allows to minimize the possibility of failure, and also allows to significantly shorten the start-up period.

Operational chemical cleaning

Operational chemical cleaning is understood as the removal of impurities from the surfaces of devices that arise during their operation, including limescale and corrosion products. In this process, appropriately selected solutions containing chemical compounds are used, which remove deposits without damaging the sheets and welded joints of devices. The final stage of chemical cleaning is the neutralization and passivation of the cleaned surface.

Operation of devices with residual sludge, depending on its composition and thickness, may result in serious failures, shorten their service life, increase fuel consumption, etc. Impaired heat transfer, due to the build-up of deposits on internal heating surfaces, leads to overheating of the materials of the devices and, consequently, to cracking of these elements. Sub-sediment corrosion which causes local pitting is an additional risk.

The release of sediment depends on:

  • supply and circulating water quality;
  • applied design and technological solutions of devices;
  • operating conditions (temperature, flows, heat load on heating surfaces, etc.);
  • method of operation;
  • technical condition of the device.

Due to the influence of these factors, the type and rate of sediment growth in the same systems may be different, as well as different in individual elements of the same system (heat exchangers, boilers, water heaters, smoke tubes, water tubes, drum).

The thicker the deposit, the more difficult it is to remove. The operation of technical devices, after reaching the critical thickness of pollutants, causes an avalanche build-up of sediment, up to clogging even large flow cross-sections. Cleaning of such items is time consuming and costly. It may happen that the cleaning costs become unprofitable.

The optimal technology for operational chemical cleaning is developed based on the sediment analysis and laboratory tests of its dissolution. Depending on the type and degree of contamination, as well as the types of materials from which the device is built, solutions of different composition and concentration are prepared. The parameters of the process, i.e. temperature, pressure and time, also depend on the degree of contamination and the type of device.

The benefits of deposit removal include:

  • improvement of heat transfer,
  • reduction of chimney losses,
  • preventing overheating of materials and the risk of corrosion,
  • reducing the number of failures and extending the life of the device,
  • a significant reduction in fuel consumption,
  • maintaining proper operating parameters of the device.

The design of modern boilers makes chemical cleaning the only available method to remove deposits, an alternative is to replace elements or piping.

Anti-corrosion maintenance process

The process of anti-corrosion maintenance protects the surfaces of devices against the so-called standstill corrosion. It is caused by the action of oxygen in the air, and in addition, corrosive processes are accelerated by moisture. Water vapor condenses and then absorbs gases in the air, such as CO2, SO2, NH3 or HCl, which form an electrolyte with it. Then, as a result of electrolytic reactions, rust forms on the surface of the material.

The anticorrosive maintenance is usually performed if the break in operation lasts more than 30 days.

Maintenance methods:

  • wet method – consists in protecting the surface by filling the device with a preservative solution,
  • dry method – consists in drying the device and filling it with an inert gas or by introducing the so-called volatile corrosion inhibitor,
  • spray method – it is used if the construction of the device allows it. It consists in spraying the preservative on the cleaned surfaces. The preservative forms a thin film that prevents atmospheric corrosion.

Blowing with steam

Although pumps with high capacity are used in the pre-operational chemical cleaning process, it cannot be guaranteed that all contaminants will be removed. Concrete pieces, stones, welding slag etc. will not be dissolved during acid treatment and the kinetic energy of the water during rinsing may not be sufficient to remove them from the system.

To remove such impurities, steam blowing is required to clean the internal heating surfaces of scale, corrosion oxides and other mechanical impurities left after assembly. Another purpose of blowing is to create a protective magnetite layer. The blowing process is indispensable and often categorically required before starting the turbine. Currently, preference is given to blowing the so-called flow method. This method consists in creating a continuous flow of steam in the boiler, which allows any impurities to be thrown outside.