Engineers are reluctant to place compact designs in even moderate fouling services because of the risk associated with “cleanability”.
It is very common practice to find only straight-tube bundles in fouling services. These bundles are also often designed with so-called “cleaning lanes”, which are arrangements of gaps in the tubing bundle that allow a clear path for hydroblasting jets through the bundle, and wider tube spacing to help prevent the entrainment of fouling within the bundle.
Designing for cleaning in this way reduces an exchanger’s heat transfer surface area and thus its total heat transfer capacity, and increases the needed equipment footprint, network size and complexity.
The advent of cleaning methods, such as ultrasonic cleaning and thermal cleaning can relieve the design concerns by ensuring that even the most compact designs can be cleaned thoroughly on both the shell and tube sides. The elimination of cleaning constraints will afford engineers the opportunity to simply and inexpensively improve heat transfer performance by replacing standard square-pitch bundles with higher performance compact designs. The added heat transfer performance may be used to improve process performance or increase maintenance intervals.