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Boiler cleaning machine

Boiler cleaning machine

4.1 before construction
4.1.1 cleaning the preparation before
4.1.1.1 boiler chemical cleaning before a detailed understanding of the structure and materials of the boiler and boiler internal and external import and export inspection carefully to determine the cleaning mode and the formulation of safety measures. Defects such as the boiler for leaks or blockage, effective measures should be taken in advance.
4.1.1.2 cleaning must be determined before the scale category. Must be in different parts of boilers with a representative scale samples were analysed. Method of identifying the scale category see Appendix 1 scale to identify the type of approach. Rated working pressure 2/5MPA boiler needed for quantitative analysis of scale-like.
4.1.1.3 must be according to the actual situation before cleaning, cleaning solution developed by the professional and technical personnel, and approved by the technical director.
Cleansing program should include the following:
(1) name of boiler units, boiler type, registration number, length of operation and last pickling time;
(2) the boiler defects;
(3) scaling or corrosion of the boiler, including scaling the distribution, thickness (or sediment), scale analysis and condition;
(4) cleaning, cleaning process;
(5) according to the "cleaning process of the laboratory experiment", material and of the structure of the boiler and boiler scale, cleaning systems determine the cleaning agent, corrosion inhibitor, passivation and its additive concentration, dosage and washing process conditions such as temperature, time;
(6) the preschool system;
(7) clean, isolation, protection measures for cutting expenditure required;
(8) in the cleaning process, should monitor and record projects
(9) cleaning the discharge of wastewater from treatment;
(10) after cleaning the cleaning or sediment cleanup, cleaning quality acceptance criteria, and so on.
4.1.1.4 cleaning prior to chemical drugs if the liquid purity, selecting corrosion inhibitors corrosion inhibitors efficiency for re-inspection, and pressing techniques, safety requirements for equipment, materials, laboratory equipment and reagents and other cleaning supplies, safety supplies ready.
4.1.2 design of cleaning system
4.1.2.1 chemical cleaning system should be based on the structure of the boiler and cleaning methods, cleaning medium, scale, distribution, boiler room and cleaning areas specific conditions and environment design.
4.1.2.2 cyclic cleaning of the boiler, the system should meet the following requirements:
(1) cleaning must be corrosion-resistant and has good volume and intensity, ensures that the cleaning fluid flow, and can be smoothly discharged sediment;
(2) cleaning pump corrosion, pump output required for cleaning should ensure the flow and head, and ensure clean pump continuous reliable operation;
(3) clean the pump inlet or wash the tank outlet should be installed filters, filter pore size should be less than 5mm, and should have adequate flow section;
(4) cleaning fluid into the tube and the sectional area of the tube should be adequate to ensure that the cleaning fluid flow and velocity of each loop should be uniform;
(5) the boiler top box should be located at the top and closed cleaning exhaust pipes. Exhaust pipe shall be led to a safe place and should have enough flow area;
(6) shall identify the monitor tubes, sampling snacks and hanging position;
(7) the valve in the cleaning system should be flexible and tight, corrosion. Containing copper parts of valves, meters and other prior to pickling remove, replace the plug or coated with anti-corrosion coating pipe attachment. Within the superheater hydrazine fills and N2H4100-300mg/L or formaldehyde oxime 100-300mg/L,PH value 9.5-10.0 (ammonia pH value adjustment) of demineralized water for protection. All systems involved in cleaning, piping should be strict isolation;
(8) if necessary, the installation of Jet injection device, steam heating and compressed air equipment
(9) should be avoided before the dirt into the system boiler and the superheater. Should generally be divided into the furnace of the boiler system, and the three systems of steam system for cleaning.
4.1.3 requirements of cleaning medium
4.1.3.1 the choice of cleaning solvent, components of the scale should be based on, boiler equipment, materials, and cleaning effect, corrosion, chemical toxicity and environmental protection requirements, and other factors considered. General through the test selection.
4.1.3.2 General case not recycled from waste acid cleaning boilers. Special cases total recycling of iron ion in acid must not exceed 250mg/L.
4.1.3.3 cleaning must be cleansed according to medium, temperature, boiler material, such as when choosing a suitable corrosion inhibitor. Inhibitors of corrosion inhibition efficiency of more than 98x10-2, and not other local corrosion, pitting corrosion and hydrogen embrittlement, and should try to choose a small smell, non-toxic, stable performance, good water solubility and uniform controlled agents.
2.3.3.1 where the cleaning required in cleaning agents, should advance to the additive inhibition efficiency determination of inhibitor after March, in case of some additives on corrosion inhibition effect. Method see Appendix 2 corrosion inhibitors corrosion inhibitors efficiency of pickling agent and method for determination of corrosion rate.
4.1.3.4 cleaning the unit should be periodically inventories of corrosion inhibitor for corrosion rate survey shall be subject to determination of boiler cleaning corrosion test pieces in place.
4.1.3.5 acid cleanser: on different scales and materials should use proper pickling agent and solvent, usually are as follows:
(1) the carbonate salt scale, generally use the hydrochloric acid cleaning.
(2) for silicate scaling, cleaning can be added to hydrochloric acid hydrofluoric acid or fluorides.
(3) for sulfate scale or mixed with silicate sulfate scale, structural changes of the alkali treatment in advance, then wash it with hydrochloric acid or HCL to add fluoride.
(4) on iron oxide scale, fluoride can be added to hydrochloric acid or nitric acid to clean.
(5) for utility boilers, when oxygen with high copper content in iron-fouling (CUO510-2), should take measures to prevent the copper plating on the metal surface, generally using fluoride hydrochloride and thiourea and other cleaning agents.
(6) cleaning of austenitic steel, do not use hydrochloric acid cleaning agent. For cleaning chromium-containing materials of boiler parts, often use hydrofluoric acid, EDTA, citric acid or formic acid and mixed acid and other organic acids cleaning agents.
4.1.3.6 Detergent dosage: boiler cleaning, the required hydrochloric acid (nitric acid), and EDTA, citric acid, corrosion inhibitor dosage calculation method see Appendix 3 of the cleaning method for calculating drug dosage. 2.4 cleaning corrosion control
4.1.3.7 must be suitable for cleaning corrosion inhibitor, said locusts and concentration and its applicability should be based on product test results. Pickling should generally be the first group of corrosion, and circulation in the system evenly, add acid. Corrosion inhibitors and acid at the same time you want to join, in uniform should be prepared before entering the boiler.
4.1.3.8 pickling required to prevent electrochemical corrosion caused by the FE3+ concentration is too high. BACK

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