4. DEVELOPMENT OF THE MET90SE
4.1 Objectives of MET90SE development
Recent years have shown strong demand for large container ships, while ships and their main engines are tending to become larger. Although it is predicted that total tonnage will decrease in the future, container ship demand is currently on a rising trend and is forecast to continue upward.
The capacity of the MET90SE was expanded, while still achieving a size small enough to allow turbocharger installation on the engine and not to interfere with maintenance. This in turn allows the use of the minimum number of turbochargers for a given engine, yielding the following advantages:
1) Achievement of sufficient turbocharger overhaul space on the engine.
2) Design simplification and cost savings due to reduction in the number of air coolers, auxiliary blowers, etc.
3) Reduction in the amount of turbocharger maintenance time.
4.2 Turbocharger external dimensions
A comparison of the external dimensions of the MET90SE and the MET83SE is shown in Fig.12. Total length is greater due to the adoption of an axial flow type silencer for the MET90SE, but, despite an expansion of capacity by approximately 30%, increases in height and width have been limited to only about 8%.
4.3 Structure
Fig.12 provides a cross-sectional drawing of the MET90SE turbocharger, which is similar in design to the MET-SE II Series that has been explained above. Fig.13 presents an external photographic view.
