I. Chemical Cleaning Method: The most common and efficient method. Suitable for removing soluble deposits such as scale, oil, and dye residue. No disassembly of the equipment is required, making it suitable for routine maintenance.
Operating Procedure:
1. Prepare the cleaning solution: For scale, use a 5% nitric acid solution; for alkaline residues, use a diluted soda ash solution; for polyester oligomers, a NaOH solution (concentration 2%-5%) is recommended.
2. Inject the cleaning solution into the system and circulate it within the heat exchanger for 30-60 minutes using a circulation pump.
3. Control the flow rate at 0.8-1.2 m/s to enhance turbulence and promote scale dissolution.
4. After draining the waste liquid, rinse repeatedly with clean water until the pH is neutral, then dry to prevent rust.
5. Precautions: Do not use strong acids or cleaning agents with high chloride ion content that are corrosive to stainless steel to avoid damaging the plates.
II. Physical Cleaning Method: For hard, thick layers of dirt.
3. Suitable for cases with severe scaling or where chemical cleaning is insufficient. Manual cleaning after disassembly is required.
Operating Points: Remove the heat exchanger plates and gently brush the surface with a soft-bristled brush or nylon brush to avoid scratching.
Do not use carbon steel brushes to clean stainless steel parts, as this will accelerate corrosion.
After cleaning, check the plates for deformation, cracks, or blocked nozzles, and replace damaged parts promptly.
Applicable Scenarios: Deep maintenance during semi-annual or annual overhauls in conjunction with chemical cleaning.
III. Comprehensive Cleaning Method: The Best Solution for Stubborn Scale For thick and hard composite scale, it is recommended to use a combination of chemical softening and physical removal.
First, soak the scale in a low-concentration alkaline or acidic solution to loosen it; then disassemble and brush to remove residual dirt; finally, reassemble and test run with clean water to confirm there are no leaks and smooth circulation.
