CCoil_Promo CCoil_ModelB CCoil_ModelC CCoil_ModelDX CCoil_ModelEX

Our tank-heating solution

For over 30 years, we have strived to provide more efficient tank-heating designs.

Columbus'Coil is a concept that redefines our views on tank heating and cargo tank heating specifically. By utilizing the vast capabilities of modern computing means, we have finally been able to prove the concept and offer Columbus'Coil, a line of brand new, more efficient tank-heating coil designs.

Columbus'Coil features:

  • A clean and compact design that simplifies equipment transportation and installation;
  • A significantly reduced installation works and lower associated impact of the weldings on the tank and double-bottom coatings;
  • A small footprint that makes the majority of the bottom of the tank free of any tank-heating equipment, providing simplified and improved tank cleaning and maintenance; and
  • Substantially improved heating efficiency that reduces the required heating coil area significantly.

How does it work?

In a nutshell, the working principle is simply determined by the position of the heating coils within the tank.

Contrary to traditional designs, in which the heating coils are uniformly extended over the bottom of the tank, Columbus'Coils are concentrated in the narrow area in the middle of the bottom of the tank, slightly asymmetrically positioned between the tank's inner and outer walls. In addition, the coils are vertically arranged, in a multitude of heating tube levels, making it a compact and convenient heating structure.

Arranged in that way, Columbus'Coils are characterized by the following features:

  • They generate a large-scale heated fluid circulation about an axis parallel to the straight tubes' longitudinal axes;
  • They enable a nearly horizontal cross-flow of the heated fluid through a void space surrounding the heating tubes; and
  • They provide a more effective heat transfer mechanism by superimposing the large-scale circulation-driven forced convection on the buoyancy-driven natural convection.

Conventional heating coil arrangement

Arrangement by using Columbus'Coils

Simulation results


Our flagship Columbus'Coil Model B conveniently combines the most important features of a new tank-heating concept: a small form factor, simplicity, favorable thermal efficiency, and ease of installation, cleaning, and maintenance.

Columbus'Coil Model B

Columbus'Coil Model C stretches new tank-heating concept features to the limits.

Columbus'Coil Model C

When the height of the heating coil bundle is a concern, Columbus'Coil Model DX conveniently combines the favorable features of the conventional and new tank-heating designs.

Columbus'Coil Model DX

Columbus'Coil Model EX shares the benefits of the Model DX design, further extending its efficiency and the consequential saving of the required heating coil area.

Columbus'Coil Model EX

Further arrangements, all based on the basic Columbus'Coil concept, are also possible.


The Columbus'Coil patent has been granted by the Korean Intelectual Property Organization (KIPO) in 2020. Afterward, in 2021, both Japan Patent Office (JPO) and China National Intellectual Property Administration (CNIPA) granted patents, too. More information may be found in the records of the World Intellectual Property Organization (WIPO):


Selected papers

Multi-level coil bundle for efficient cargo tank heating
Journal of Marine Science and Application 20(2021), 467-476.
Circulation-enhanced tank heating using shallow profile coil bundles
Journal of Marine Science and Application 19(2020), 234-245.
Vertical arrangement of coils for efficient cargo tank heating
International Journal of Naval Architecture and Ocean Engineering 11(2019), 662-670.
Cargo tank heating using vertically arranged heating coils
23rd Symposium on Theory and Practice of Shipbuilding SORTA 2018, Split, 27-29 September 2018, University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture.
Numerical analysis of tank heating coil heat transfer process
In: Guedes Soares, et al. (Eds.), Towards Green Marine Technology and Transport, CRC Press, London 2015.
Computer aided design and analysis of tank heating
Brodogradnja 35(1987)4, 193-202. (in Croatian)

A note on the numerical results

All the numerical results provided herein are based on computational fluid dynamics (CFD) simulations performed by using the same standard set of input data, comprising:

  • A residual fuel oil with a 991 kg/m3 nominal density, 585 mm2/s (585 cSt) nominal kinematic viscosity, and 55°C temperature;
  • 50A steel heating coils fed by an 8 bar (abs.) steam; and
  • Environmental conditions comprising 2°C air temperature and 5°C sea temperature.

In addition, the provided numerical comparisons are based on the conventional heating coil arrangement depicted above.