Causes of blockage in plate heat exchangers

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Plate heat exchangers are a type of heat exchanger with high heat transfer efficiency. They feature high thermal conductivity, small footprint, low heat loss, flexible assembly, and ease of disassembly and cleaning. They have been widely used in various industries such as food processing, pharmaceuticals, power generation, metallurgy, heating, paper manufacturing, machinery, and chemicals. However, the flow cross-sectional area of the channels in plate heat exchangers is small, which makes scaling and blockage more likely to occur during use. This reduces the heat exchange efficiency of the plate heat exchangers, affecting the operation process and performance. Therefore, regular or proper cleaning of plate heat exchangers plays a very important role in improving heat exchange efficiency and extending their service life. Reasons for blockage in plate heat exchangers: 1. Impurities present in the heat exchange medium enter the connection pipes, causing blockage in the heat exchanger. It is usually due to leftover welding rods and slag from the pipeline welding process, or impurities such as sand and debris remaining in the pipeline during construction. 2. Scaling in the circulating water causes blockages in the heat exchangers. The main cause of scale formation is the presence in water of calcium and magnesium salts with low solubility; their solubility decreases as the water temperature rises, causing them to turn into insoluble salts. These insoluble salts can have a significant impact on the heat exchange efficiency of the heat exchanger. 3. Rust formation on the inner wall of the pipes, leading to blockages as the circulating water enters the heat exchanger. During the shutdown of the heat exchanger, the rate of rusting accelerates; therefore, it is important to clean the heat exchanger during this period. The main cleaning methods for plate heat exchangers include mechanical cleaning, chemical cleaning, and physical cleaning. Improper cleaning methods can cause damage to the heat exchange equipment itself, the plates, or the gaskets, and may even render the equipment unusable. Therefore, professional personnel are needed to maintain and clean the heat exchanger to prevent it from becoming clogged.