What Preparations Should Be Made Before Chemical Cleaning Of Industrial Boilers?

Industrial boilers provide steam or hot water (see hot water boilers) for industrial and mining enterprises to meet the needs of production process, power and heating. Industrial boilers have a wide range of uses, large quantities, and large fuel consumption. What preparations should be made before chemical cleaning of industrial boilers?

1 Before chemical cleaning of the boiler (industrial cleaning|chemical cleaning|boiler cleaning|heat exchanger cleaning), you should understand the structure and material of the boiler, and carefully inspect the inside and outside of the boiler to determine the cleaning method and formulate safety measures. If the boiler has defects such as leakage or blockage, effective measures should be taken to deal with it in advance.

2 The type of scale must be determined before cleaning. Representative scale samples should be taken from different parts of the boiler for analysis. For the identification methods of scale species, see Appendix 1 "Methods of Identification of Scale Species". Boilers with rated working pressure ≥ 2.5MPa need to be quantitatively analyzed for scale samples.

3 Before cleaning, a cleaning plan must be formulated by a professional technical staff based on the actual situation of the boiler and approved by the technical person in charge. The cleaning plan should include the following:

(1) The name of the boiler using unit, boiler model, registration number, operating life and last pickling time, etc.;

(2) Whether the boiler has defects;

(3) The status of boiler fouling or rust, including scale distribution, thickness (or amount of deposit), scale analysis results and equipment status;

(4) Cleaning scope and cleaning process;

(5) Determine the concentration, dosage, cleaning temperature, time and other processes of cleaning agents, corrosion inhibitors, passivators and other auxiliary agents based on the "small-scale cleaning process test", boiler structure and boiler material and scale, cleaning system, etc. premise;

(6) Diagram of chemical cleaning system;

(7) Throttle, isolation, and protection measures required for cleaning;

(8) Items that should be monitored and recorded during the cleaning process;

(9) Discharge treatment of cleaning waste liquid;

(10) Sweeping or residual dirt cleaning after cleaning, prerequisites for cleaning quality acceptance, etc. The cleaning plan should be strictly implemented during the chemical cleaning of the boiler. If the plan needs to be changed under special circumstances, the technical person in charge of the original approved plan should sign and agree.

4 Before cleaning (industrial cleaning|chemical cleaning|boiler cleaning|heat exchanger cleaning), the chemical cleaning chemicals, such as the purity of the stock solution, the corrosion inhibition efficiency of the selected corrosion inhibitor, etc., should be retested, and the requirements of technical safety measures should be followed. Good preparation of equipment, materials, laboratory equipment and reagents, safety supplies and other items needed for washing.