What preparations need to be made before chemical cleaning of industrial boilers?

1.1 Preparation before cleaning.

1.11 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, carefully check the inside and outside of the boiler, determine the cleaning method, and formulate safety measures. If the boiler has defects such as leakage or blockage, effective measures should be taken in advance to deal with it.

1.12 The type of scale must be determined before cleaning. Representative scale samples should be drawn from different parts of the boiler for analysis. For the method of identification of scale species, see Appendix 1 "Method of Identification of Scale Species". For boilers with a rated working pressure ≥ 2.5 MPa, the scale samples should be quantitatively analyzed.

1.13 Before cleaning, professional and technical personnel must formulate a cleaning plan according to the actual situation of the boiler and obtain the approval of the technical person in charge. The cleaning plan should include the following:

(1) Boiler user name, boiler model, registration number, service life and last pickling time, etc.

(2) Whether the boiler is defective;

(3) Scaling or corrosion of boilers, including scaling distribution, thickness (or deposition amount), scaling analysis results and equipment condition

(4) Cleaning scope and cleaning process;

(5) Determine the concentration and dosage of cleaning agents, corrosion inhibitors, passivators and other additives, as well as cleaning temperature and time according to the "cleaning process pilot", boiler structure, boiler material and scale amount, cleaning system;

(6) Diagram of chemical cleaning system;

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

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

(9) Discharge treatment of cleaning waste liquid;

(10) Residual scale cleaning after cleaning or cleaning, prerequisites for cleaning quality acceptance, etc. Boiler chemical cleaning should strictly implement the cleaning plan. If the plan needs to be changed under special circumstances, the person in charge of the technology who originally approved the plan shall sign and agree.

1.14 Before cleaning (industrial cleaning|chemical cleaning|boiler cleaning|heat exchanger cleaning), the purity of the stock solution, the selection of corrosion inhibitors and the efficiency of corrosion inhibitors and other chemical cleaning drugs should be rechecked, and the equipment required for cleaning should be prepared according to the requirements of technical safety measures. , Materials, laboratory equipment, reagents, safety supplies and other items.