Heat exchanger tube blockage rate
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Due to internal pipe leakage in the heat exchanger, active pipe plugging is carried out; what percentage of plugging is required before the heat exchanger can be considered unusable?
The standard practice is 10% scrap. It actually depends on what the design margin of the heat exchanger is. Those with a large design margin can have more blocks, as long as it does not affect production.
Generally 10-15%, with the main factor being the heat exchange efficiency of the process
During the manufacture of heat exchangers, a tube blockage rate of less than 1.5% is allowed. In process design, the area of the heat exchanger is typically set at 1.1 to 1.2; in other words, under normal conditions, a tube blockage rate of 10% to 20% should be sufficient to meet the process requirements, and a decision can be made based on actual circumstances.
I work on the repair of corrosion on heat exchanger tube sheets as well as on anti-corrosion treatments; I’d like to learn some knowledge about heat exchangers.
It depends on the actual heat exchange efficiency of the heat exchanger. Simply put, after a tube gets blocked, the temperature distribution throughout the heat exchanger changes; at this point, it is only possible to determine whether the heat exchanger is working properly by observing its heat exchange performance on site. Judging based on the level of richness in the design is unreliable.
In our company, we usually replace the tube bundle when the percentage exceeds 10%; of course, there are exceptions – the tube bundle does not need to be replaced as long as it does not affect heat exchange.
I learned it! I think it’s mainly due to the design values! It’s not possible to rely solely on proportions; it is the amount of excess that determines the number of pipes that can be blocked
Check the design margin and actual operating conditions
Under design conditions, the margin for the basic heat exchange area is usually around 20%. However, as the heat transfer coefficient decreases over time, the degree of blockage in the tubes should not exceed 20%. Calculate the heat transfer coefficient yourself, determine what size of heat exchange area is required to meet the specifications, and then assess the level of tube blockage