Cappuccino effect remains still one of the most common and widely used ‘mal-practice’ in the bunkering industry to-date. Despite lot of articles and loss prevention bulletins being issued by various P&I Clubs; we are still seeing lot of vessel’s falling victim to this ill-practice. Often our expertise is called upon at the next port of call when the vessel just five days into her voyage after stemming bunkers would discover a sudden “disappearance” of 30-40 MT overnight. It is then too late for us or anyone to do anything! The short article that follows focuses only on “cappuccino bunker effect” giving the reader a better understanding and grasp of the subject matter.
What is Cappuccino Effect:
Cappuccino effect essentially may be described as frothing/bubbling effect caused by compressed air blown through the delivery hose. The aerated bunkers when sounded will give the impression that the fuel is delivered as ordered. In fact after sometime when the entrapped air in suspension settles out of the fuel oil the oil level drops and a short fall is discovered. In large bunker deliveries this could be considerable with huge financial implications.
We have often been asked why the flow meter cannot detect the air being introduced in the system and compensate accordingly. Well, most flow meters in use today are of either the wrong type or the wrong size. In other words are not technologically advanced. All the standard flow meters will only measure the volume of throughput and not the actual mass of fuel being delivered. As a result when is air introduced into the system, which is essentially ‘small air bubbles’ – the flow meter will register it as volume.
However, there are flow meters out in the market which are capable of measuring the true quantity (mass) of the fuel delivered. One such meter is the ‘Coriolis Mass Meter’ – it has been in existence for quite some time now and only getting better. Coriolis meters take direct mass flow measurements using the Coriolis Effect (a deflection of moving objects when they are viewed in a rotating reference frame –we won’t be discussing this effect as this is beyond the scope of this article). Coriolis meters are less sensitive to pressure, temperature, viscosity, and density changes, allowing them to measure liquids, slurries and gases accurately without the need for compensation. These meters having no moving parts require little maintenance however, the initial cost and line modifications is usually a deterrent for many ship operators for not installing it.