Twisted Tape Enhancement
Twisted tape are simple enhancement devices which can be installed into new or existing tubular exchangers. They are a long-established solution with performance prediction methods available both in the public domain and in heat transfer simulation software. Cal Gavin have also collected their own data for these devices which provides additional confidence in application engineering.
Twisted tape enhancement is achieved by inducing swirl flow in the tubeside fluid and offers a modest increase in heat transfer at low additional pressure loss. The low pressure drop characteristic makes them a reasonable option for turbulent flow. Twisted tapes offer a limited benefit in laminar and transitional flows where they are not as effective as hiTRAN Thermal Systems. They should be avoided for deep laminar flow where performance appears to deteriorate noticeably.
The heat transfer and pressure drop characteristics can be varied somewhat by changing the twist pitch of the device. Typical twist pitch ratios (360o twist pitch / tape width) are between 6 and 16.
The width of the tape is specified to allow a small gap between the tape and the tube wall. Tapes are installed by either pushing or pulling them into the tubes. They are fully removeable for cleaning.