MAN B&W
15.04
Page of
MAN Diesel
MAN B&W S50MC6, S50MC-C/ME-C7/8, S50ME-B8/9
198 63 96-8.0
Exhaust gas silencer
The typical octave band sound pressure levels
from the diesel engine’s exhaust gas system – at a
distance of one meter from the top of the exhaust
gas uptake – are shown in Fig.15.04.0.
The need for an exhaust gas silencer can be de-
cided based on the requirement of a maximum
permissible noise level at a specific position.
The exhaust gas noise data is valid for an exhaust
gas system without boiler and silencer, etc.
The noise level is at nominal MCR at a distance of
one metre from the exhaust gas pipe outlet edge
at an angle of 30° to the gas flow direction.
For each doubling of the distance, the noise level
will be reduced by about 6 dB (farfield law).
When the noise level at the exhaust gas outlet to
the atmosphere needs to be silenced, a silencer
can be placed in the exhaust gas piping system
after the exhaust gas boiler.
The exhaust gas silencer is usually of the absorp-
tion type and is dimensioned for a gas velocity of
approximately 35 m/s through the central tube of
the silencer.
An exhaust gas silencer can be designed based
on the required damping of noise from the ex-
haust gas given on the graph.
In the event that an exhaust gas silencer is re-
quired – this depends on the actual noise level
requirement on the bridge wing, which is normally
maximum 6070 dB(A) – a simple flow silencer of
the absorption type is recommended. Depending
on the manufacturer, this type of silencer nor-
mally has a pressure loss of around 0 mm WC at
specified MCR.
Spark arrester
To prevent sparks from the exhaust gas being
spread over deck houses, a spark arrester can be
fitted as the last component in the exhaust gas
system.
It should be noted that a spark arrester contrib-
utes with a considerable pressure drop, which is
often a disadvantage.
It is recommended that the combined pressure
loss across the silencer and/or spark arrester
should not be allowed to exceed 100 mm WC at
specified MCR. This depends, of course, on the
pressure loss in the remaining part of the system,
thus if no exhaust gas boiler is installed, 00 mm
WC might be allowed.
Fig. 15.04.02: ISO’s NR curves and typical sound pres-
sure levels from the engine’s exhaust gas system. The
noise levels at nominal MCR and a distance of 1 metre
from the edge of the exhaust gas pipe opening at an angle
of 30 degrees to the gas flow and valid for an exhaust
gas system – without boiler and silencer, etc. Data for a
specific engine and cylinder no. is available on request.
178 59 42-1.0
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Summary of Contents for B&W S50ME-B9.3-TII
Page 4: ......
Page 10: ......
Page 11: ...MAN B W MAN Diesel Engine Design 1 ...
Page 12: ......
Page 27: ...MAN B W MAN Diesel Engine Layout and Load Diagrams SFOC 2 ...
Page 28: ......
Page 53: ...MAN B W MAN Diesel Turbocharger Selection Exhaust Gas By pass 3 ...
Page 54: ......
Page 58: ......
Page 59: ...MAN B W MAN Diesel Electricity Production 4 ...
Page 60: ......
Page 92: ......
Page 93: ...MAN B W MAN Diesel Installation Aspects 5 ...
Page 94: ......
Page 124: ......
Page 133: ...MAN B W MAN Diesel List of Capacities Pumps Coolers Exhaust Gas 6 ...
Page 134: ......
Page 154: ......
Page 155: ...MAN B W MAN Diesel Fuel 7 ...
Page 156: ......
Page 170: ......
Page 171: ...MAN B W MAN Diesel Lubricating Oil 8 ...
Page 172: ......
Page 188: ......
Page 189: ...MAN B W MAN Diesel Cylinder Lubrication 9 ...
Page 190: ......
Page 199: ...MAN B W MAN Diesel Piston Rod Stuffing Box Drain Oil 10 ...
Page 200: ......
Page 202: ......
Page 203: ...MAN B W MAN Diesel Central Cooling Water System 11 ...
Page 204: ......
Page 209: ...MAN B W MAN Diesel Seawater Cooling System 12 ...
Page 210: ......
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Page 221: ...MAN B W MAN Diesel Starting and Control Air 13 ...
Page 222: ......
Page 227: ...MAN B W MAN Diesel Scavenge Air 14 ...
Page 228: ......
Page 239: ...MAN B W MAN Diesel Exhaust Gas 15 ...
Page 240: ......
Page 254: ......
Page 255: ...MAN B W MAN Diesel Engine Control System 16 ...
Page 256: ......
Page 265: ...MAN B W MAN Diesel Vibration Aspects 17 ...
Page 266: ......
Page 280: ......
Page 281: ...MAN B W MAN Diesel Monitoring Systems and Instrumentation 18 ...
Page 282: ......
Page 302: ......
Page 306: ......
Page 307: ...MAN B W MAN Diesel Dispatch Pattern Testing Spares and Tools 19 ...
Page 308: ......
Page 322: ......
Page 323: ...MAN B W MAN Diesel Project Support and Documentation 20 ...
Page 324: ......
Page 332: ......
Page 333: ...MAN B W MAN Diesel Appendix A ...
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