Tubular Heat Exchangers are designed and manufactured to provide the highest level of heat transfer efficiency to the process wherein they are installed. For many processes, additional contributing factors including the size, location, duty, materials and serviceability of heat exchangers dictate the design criteria with often cumbersome results.
With near to 40 years experience in the design and manufacture of tubular heat exchangers, we understand that these factors are critical to the decision making process when it comes to purchasing a heat exchanger. That’s why Teralba’s Dimpleflo® tubular heat exchangers have been developed to provide adaptability to almost any process through the use of the dimple profile.
Currently, there are many different configurations of tubular heat exchangers in the market that include different geometries including fins, corrugations and spirals. Though many have their specific application and they are all designed to provide effective heat transfer solutions, Dimple profiled tube has some proven and unrivalled advantages over other tubular heat exchanger designs.
The dimpled tube allows the following benefits in tubular heat exchangers:
1. Disrupts Laminar Flow patterns
The profile of dimples affects the core of the fluid flow as well as the boundary layer especially with viscous and laminar flows.
2. Heat Exchanger will Completely Drain
Dimpleflo® Heat Exchangers fully drain due to a free draining path when the profile is arranged at the 6 o’clock position. Other profiles such as corrugations do not fully drain and promote particulate deposits and fouling on the reverse side of the corrugation profile.
3. Anti-Fouling
Dimples bring significant vortices to flow behaviour and generate a self-scouring effect that has proven in many applications to be anti-fouling. This means the more the heat exchanger runs the better it performs.
4. Varying Design Combinations for Specific Duties
Dimples are arranged in various depths and combinations designed to achieve a specific duty. No other profiles provide this level of flexibility for bespoke designs.
5. Fluid Mixing Intensity
Fluid mixing intensity is comparable to that achieved by inserted static mixing elements, minus the usual pressure drop increases and blockages.
6. Lower Work hardening effect on tubes
Dimples Have significantly lower work hardening affect on the tube material compared to most other tube profiles which reduces the risk of stress corrosion cracking.
7. Suitable for Pigging System
Able to be cleaned with pigging systems and projectiles for product reclaim reducing wastage.
8. CIP
Easy to clean in place (CIP) as there is a dedicated fluid flow and increased turbulence even at lower flow velocities.
In summary, the Dimple profile tube has an unrivalled advantage when it comes to product fouling as opposed to other heat exchanger tube designs such as plain, corrugated and finned tubes. The dimples bring significant vortices to flow behaviour and generate a self-scouring effect, meaning they are anti fouling. In many situations where there is evidence of fouling on plain tube connections of a Dimpleflo® there is little to no fouling on the dimpled tube walls. This is a result of the dimples working to disturb laminar flow behaviours, these turbulence enhancing deformations generate eddies and vortices that have an added benefit of minimising fouling.
The dimple tube profiles ability to disturb the core of the flow through the tubes which increases the rate of heat transfer and efficiency.
References:
Many in-depth studies have been conducted on the effectiveness of dimpled tube in heat exchangers, with affirming conclusions.
Click the below links to read these in depth studies on dimpled tubing.
Teralba Industries