Heat exchangers : a common source of problems
Shell and tube heat exchangers installed horizontally, with steam injected tube-side, are especially prone to water hammer.
In some plants, it is necessary to ‘modulate’ in order to adapt output temperature to a variety of products. When demand decreases, there is a pressure drop in the heat exchanger. This pressure drop creates a vacuum that retains the condensate inside the exchanger. When, at a later time, demand increases again and steam starts entering the exchanger, it gets in contact with cooled condensate. This results in water hammer which, over time, can destroy the exchanger. In many plants, heat exchangers are replaced every two years or so as a result of water hammer damage. This, however, is perfectly avoidable.
The Lalonde Systhermique heat exchanger
The Lalonde Systhermique team has designed an exclusive shell and tube heat exchanger, built in Quebec according to our specifications. This heat exchanger is specifically designed for closed systems. Its design and vertical installation allow it to work on a large spectrum of temperatures without being subject to water hammer. Consequently, instead of lasting just a few years, our heat exchangers have a normal useful lifespan (up to 40 years). In a Lalonde Systhermique SCCS®, heat exchangers work just a well in batch processes as in continuous processes.
The way we install our heat exchangers also contributes to maximize heat transfers, increase reliability and allow optimal temperature control. This allows us to guarantee an extremely precise output temperature (± 0.5 oF).