How to Maintain Plate Heat Exchanger for Efficient Operation

 
Plate heat exchangers are highly efficient heat transfer devices widely used in industries such as chemical processing, pharmaceuticals, food processing, and HVAC systems. To ensure their long-term efficient and stable operation, regular maintenance and prompt troubleshooting are essential. This article provides a detailed guide on the maintenance procedures, common issues, and troubleshooting methods for plate heat exchangers.
 

Maintenance of Plate Heat Exchangers

Proper maintenance of plate heat exchangers is essential to ensure their efficient and long-lasting operation. The following steps outline crucial maintenance procedures.
 
1. Frost Protection

During seasonal shutdowns, it is crucial to drain the medium inside the heat exchanger or take other effective frost protection measures to prevent damage from freezing, especially in colder regions.
 
2. Long-term Shutdown Maintenance

If the equipment is not in use for an extended period, the tightening bolts should be loosened to the specified size. This prevents deformation of the gaskets and heat exchanger plates due to prolonged pressure. When resuming use, tighten the bolts as required.
 
3. Operational Maintenance

Regularly running equipment requires monitoring of the signal hole. If medium leakage is detected, perform a thorough analysis:
 
If the cause is loose bolts or bolt elongation due to prolonged heat exchange, retighten according to specifications, but avoid over-tightening to prevent damaging the plates.

If the gaskets are aged, they should be replaced promptly.
 

Troubleshooting Plate Heat Exchangers

 
After long-term operation, plate heat exchangers may encounter several common issues that need immediate attention.
 
1. Gradual Increase in Pressure Drop

A gradual increase in pressure drop is typically caused by unclean media or excessive particulate matter, leading to fouling on the plates or blockage of the flow channels. In this case, stop the equipment, loosen the nuts, remove the tightening rods, and move the movable plate to the column end. Remove the plates and clean them with water or soapy water. Use a brush or fiber brush to remove any adhered substances, avoiding metal brushes.
 
2. Media Mixing

If the primary and secondary side pressures increase or decrease simultaneously, the cause might be perforation of the plates due to corrosion. Conduct a light inspection of the plates or alternately pressurize each side to locate the cracked plates and replace them.
 
3. Leakage

Leakage is often due to aged gaskets, inappropriate gasket material selection, or loose nuts on the tightening bolts. When leakage occurs, first check if the nuts are loose and if the tightening size matches the equipment installation diagram. If the nuts are loose, retighten them to the correct dimensions. If leakage persists, open the equipment to inspect the gaskets. If the gaskets have slipped out of their grooves, reapply them or replace damaged gaskets. When multiple gaskets are damaged simultaneously, ensure to select suitable material for the new gaskets.
 
The efficient operation of plate heat exchangers relies on regular maintenance and inspections. Implementing frost protection, performing long-term shutdown maintenance, conducting operational checks, and promptly addressing issues like pressure drop increases, media mixing, and leakage can significantly extend the equipment's service life. Regular maintenance enhances performance, reduces failure likelihood, lowers repair costs, and improves operational efficiency.