What are the consequences of scaling in plate heat exchangers?

1. Decreased heat transfer efficiency and significantly increased energy consumption: Scaling increases heat transfer 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 scaling can even result in efficiency losses exceeding 50%. To maintain the process temperature, the system must increase pump power or increase the medium flow rate, leading to a surge in electricity and steam consumption and a significant increase in long-term operating costs.

2. Increased system pressure drop and heavier equipment load: Scaling and blockage narrow the flow channels between plates, increasing fluid flow resistance and significantly increasing the system pressure drop. This not only increases the load on the circulating pump and shortens its service life but may also cause abnormal pipeline pressure, leading to valve leaks and seal failures. In extreme cases, local blockage can create fluid "dead zones," causing some heat exchange plates to completely lose their function and exacerbating uneven equipment operation.

3. Accelerates equipment corrosion and shortens overall lifespan: Scale deposits such as calcium carbonate and calcium sulfate are corrosive and can form localized concentration cells under the scale, accelerating pitting or crevice corrosion of stainless steel plates. Once the plates perforate, hot and cold media mix, leading to product contamination or even system shutdown for maintenance. Frequent improper cleaning can further damage the plate material, significantly shortening equipment lifespan.

4. Affects process stability and threatens product quality: In industries with high temperature control requirements, such as food, beverage, and pharmaceuticals, the reduced heat exchange efficiency caused by scaling can lead to inaccurate temperature control. For example, if the pasteurization temperature of milk is not up to standard, it can cause excessive microbial levels, resulting in the scrapping of the entire batch of products or even endangering consumer health.

5. Increased maintenance costs and risk of unplanned downtime: Scaling requires regular shutdowns for cleaning, which is not only costly in terms of manpower and resources, but also disrupts normal production. If not dealt with in time, it may also cause sudden failures and unplanned downtime. According to industry statistics, unplanned downtime caused by heat exchanger scaling will cause hundreds of millions of yuan in indirect losses to industrial enterprises every year.