- High efficiency (generally greater than 85%) hence reduced fuel consumption.
- Flexibility of design -- important space consideration.
- Capable of high out put (i.e. high evaporation rate).
- High pressures and temperatures improve turbine plant efficiency.
- Flexible in operation to meet the fluctuating demands of the plant, - superheat control rapidly responsive to changing demands.
- Generally all surfaces are circular hence no supporting stays are required.
- Steam can he raised rapidly from cold if the occasion demands, (3 to 4 hours compared to 24 hours for a Scotch boiler) because of the positive water circulation.
Compact and relatively light (water content up to 7.5 tons compared with 30 tons for a Scotch boiler). - With double easing radiation loss can he cut to 1% or less.
1. High cost: Manganese bronze is a costly alloy, making it less economical for large propellers. 2. Low strength-to-weight ratio: Compared to other propeller materials like nickel-aluminum bronze or stainless steel, manganese bronze has a lower strength-to-weight ratio. 3. Susceptible to corrosion: Manganese bronze can corrode in seawater, especially when exposed to high velocities and turbulence. 4. Poor cavitation resistance: Manganese bronze is more prone to cavitation damage than other materials. 5. Difficult to cast and machine: Manganese bronze is challenging to cast and machine, making it less desirable for complex propeller geometries. 6. Limited weldability: Manganese bronze has poor weldability, making repairs and modifications difficult. Nickel-aluminum bronze or stainless steel are commonly used for propellers due to their: - High strength and durability - Excellent corrosion resistance - Good cavitation resistance - Ease of casting and machining - Weldability
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