Lightfoot International successfully complete large scale marine refrigeration system flush
CLIENT INTRODUCTION
AW Ship Management Ltd is a UK based company providing ship management services for a range of vessel operators. AW appointed Lightfoot International to evaluate a failure of a managed vessel’s AC system.
PROBLEM STATEMENT
After suffering twin compressor failure due to a fractured sea water condenser, Lightfoot International Engineers were initially called in to assess the system for repair and re-commissioning. Upon removal of the compressor cylinder heads it quickly became apparent the system was severely contaminated, and emulsification had started to take place.
THE SOLUTION
Due to the size of the system and the fact that it traverses through multiple decks from the machinery space to the upper deck crew quarters, Lightfoot chose to break the system down into smaller sections. Not only did this ensure a thorough flush of the pipework and components it meant we could strategically position equipment and materials at set locations around the ship. Which ordinarily would have posed their own logistical issues and caused costly delays for the customer whilst equipment was craned around the ship. Thankfully our careful planning and execution meant we were able to avoid this.
The F30S Flushing machine was setup and controlled from the Machinery Compartment to allow 1100Kg’s of flushing refrigerant to be injected into the pipework in a liquid state rather than pulled in a vapour state. Resulting in total surface saturation of the suction line pipework and maximum removal of oil, particulates, and other contaminants that are held in suspension on a surface or in water in liquid form.
The suction and liquid lines were manually flushed throughout the course of the day, the initial sight glass inspection showed severe oil contamination with large droplets of oil clinging to the inside of the glass. At the end of the day, the sight glass was isolated and removed from the F30S for inspection and cleaning. Inspection showed a heavily soiled sight glass filter having trapped emulsified oil and particulate. Over the course of the pipework flushing approximately 20 litres of excess oil was removed from the suction and liquid pipework.
THE OUTCOME
Lightfoot International had not flushed a system of this size previously, despite this, we assessed the customers requirements and devised a plan that would achieve the customers desired outcome.
After travelling with the ship for two weeks going to and from the UK to Europe our engineers successfully cleaned the system of all contamination. The system was then successfully pressure tested and vacuum dehydrated to 1.3 torr, after which point it could be charged with refrigerant.