What performance characteristics are affected by fouling in plate heat exchangers?

1. Significantly reduced core heat exchange performance: Scale increases thermal resistance and reduces the heat transfer coefficient. When the scale thickness reaches 0.5mm, the heat transfer efficiency can decrease by more than 20%, and severe fouling can even result in efficiency losses exceeding 50%, failing to meet design heat exchange requirements.

2. Deteriorated fluid flow performance: Scale blocks narrow flow channels between plates, increasing fluid flow resistance and significantly raising the system pressure drop. When the pressure drop reaches more than 1.3 times the initial pressure drop, it will affect normal flow rate, requiring increased pump power to maintain operation and increasing energy consumption.

3. Impact on equipment sealing and structural performance: Increased system pressure drop increases the load on the sealing structure and circulating pump, easily leading to seal leaks and shortened pump life. Severe blockage can also create fluid "dead zones," causing some heat exchange plates to completely lose their function, exacerbating uneven equipment operation, and eventually causing plate stress deformation.

4. Decreased Corrosion Resistance: Scale itself is corrosive and can form localized concentration cells beneath it, accelerating pitting corrosion of stainless steel plates, impairing their corrosion resistance, and in severe cases causing perforation and mixing of hot and cold media.

5. Unstable Process Control Performance: In production scenarios requiring precise temperature control, the reduced heat exchange efficiency caused by scaling can lead to inaccurate temperature control, directly affecting product quality. For example, in food sterilization processes, substandard temperatures can result in excessive microbial levels.