MARINE EXHAUST
The modern exhaust gas system of marine engines is designed in such a way that the unused gases coming out of the cylinders are further directed to turbocharger and exhaust gas boiler to recover most of the waste energy from the same. The exhaust gas piping system conveys the gas from the outlet of the turbocharger(s) to the atmosphere. For designing the exhaust piping system, following important parameters must be observed:
The Exhaust gas system of engine experiences huge temperature variations. It is not possible to construct the entire exhaust piping system in one single piece hence; multiple sections are joined to complete the system. When the engine is standstill, the temperature of the exhaust pipe may vary from 10 to 40 °C (depending upon the surrounding environment or geographical location of the ship) and when the engine is up and running, the exhaust system temperature crosses 200 °C. This major temperature variation requires need of joints to safely absorb the heat-induced expansions and contractions of pipes and tubing systems. For this purpose, bellows and expansion joints are used. They are designed accurately to make sure that they are able to withstand the stresses and avoid cracks brought about by the continuous change in the temperature of the system.
The expansion joints are to be chosen with an elasticity that limits the forces and the moments of the exhaust gas outlet flange of the turbocharger as stated for each of the turbocharger makers. The Expansion joints are placed at various places spreading it in the exhaust gas piping system of the marine engine.
Our exhaust bellows are designed with high flexibility and long life, low thickness and multi layered design helps increasing service life to operate in the presence of long term vibration exposure. They are designed to accommodate the natural frequencies during engine start up and to avoid the natural frequency signature of engines in their normal operating range. Low spring rate configuration helps to reduce the spring loads on the fixations.
