Enhanced heat transfer tubes, otherwise known as enhanced surface tubes characterized by changes in shape to effect improvements in heat transfer performance compared with orthodox heat exchanger tubes of circular cross section. In this regard, enhanced heat transfer tubes are to be distinguished from extended surface tubes, in which heat transfer performance is improved by increasing the effective surface area available for the heat transfer duty. This can be achieved by superimposing fins on the inside or outside surfaces, and by the use of additional sections inserted inside the tubes or grooves.
Tubes of both types have been known for many years. The heat transfer aspects of enhanced tube technology now appear to be sufficiently well understood for most practical requirements. The main problem with regard to manufacture of such tubing is to devise satisfactory methods for making technically acceptable tubes at commercially acceptable prices. These production problems have now been resolved with the patented Spirex tube manufacturing process.
Vaportec NZ Ltd has developed extensive knowledge over the early six years during the research and development period, concentrating on the manufacture of Spirex tube and the design, build and installation of various working uses of heat transfer equipment.
This has provided substantial "in place" (before and after) data which provides the basis of our design and application criteria. The inherent advantages of Spirex tube began with the formation of the spirals. The method increases the surface area over a shorter lineal length, and combined with the induced turbulence, culminates in an enormous increase in overall heat transfer coefficient. Improvements over plain tubing include substantial increase in collapsing strength, reduction in size of heat exchangers and increased heat transfer coefficients.
The new Vaportec helically corrugated heat transfer tubing system lies at the heart of every Vaportec tubular heat exchanger. This new technology is the result of ongoing development in heat exchanger manufacturing and these heat exchangers are available in a variety of materials such as copper, stainless steel and Titanium.
The dynamic properties encouraged by the helical form of SPIREX perforated tube offer new and effective alternatives in: