Heat exchangers are a critical part of sterilisation procedures in food and drink manufacturing, particularly in high-risk products such as dairy. HRS Heat Exchangers looks at the improved efficacy of corrugated tubes over smooth tubes in tubular heat exchangers.
UK company HRS Heat Exchangers has had an office in Australia since 2013. The Melbourne location offers sales, project and after-market services to the company’s customer base in the Asia-Pacific region.
HRS claims its tubular heat exchangers provide “unrivalled” heat exchange capacity and consistent performance, which the company credits to its use of corrugated tube technology.
Heat exchanger options
The three most common types of heat exchanger are plate heat exchangers, tubular heat exchangers and scraped surface heat exchangers.
Plate heat exchangers are suitable for use with simple viscous fluids such as water, milk, and some thin oils, while highly viscous materials or those which require thorough mixing often require scraped surface heat exchangers.
For most materials between these two extremes, tubular heat exchangers are the preferred choice.
The biggest influence on the efficiency of tubular heat exchangers is the type of tube used, and HRS has found corrugated tubes to be more efficient at transferring heat than smooth ones.
Increased efficiency
When a fluid moves through a tube, the dynamics are affected by factors such as pressure, viscosity, and the design of the tube wall.
In a smooth tube, fluids usually follow a smooth path in which the particles which make up the fluid do not interfere with each other – known as laminar flow. However, where the smooth flow is disrupted, tiny whirlpools form in the fluid creating a turbulent flow.
Due to turbulence, tubular heat exchangers are made more efficient by preventing viscous or suspended materials sticking to the wall of the tube. This can form a boundary layer, which acts as insulation and prevents efficient heat transfer.
The creation of this turbulent flow, and the resulting improved efficiency compared to a smooth tube, is the key benefit of corrugated tube heat exchangers.
Other benefits
A corrugated tube has a higher heat transfer rate, compared to a smooth tube of the same length, so they can be smaller, and cheaper to manufacture
The thermal efficiency can be up to three-times that of a smooth tube heat exchanger – which makes HRS Heat Exchangers popular for space-restricted installations.
The corrugated tube also reduces the formation of a boundary layer, reducing cleaning and maintenance time.
HRS Heat Exchangers uses exclusively corrugated tubes in its non-scraped tubular heat exchangers because of these benefits. The range can be viewed online at hrs-heatexchangers.com.
