Types - Front Silencer

Front Silencer

In a typical 4-cylinder engine, combustion takes place between 1,500 to 6,000 times per minute. The silencer reduces the resultant sound waves to acceptable levels and ensures correct gas flow through the exhaust system.

A silencer is a combination of tuning chambers, baffle partitions and perforated and solid tubes designed to dissipate noise pulses while moving exhaust gases and vapor.

Two basic principles are used to reduce noise levels.

In the absorption principle, absorbent material—rock wool, fiber-mat, roving fiber glass (E-glass) is stuffed into the silencer cavities to eliminate unwanted exhaust sound. Friction transforms sound energy into thermal energy.

In the reflection principle, sound waves can also be reduced by by-passing obstacles such as baffles or changing the diameter of the transient tube.

Most exhaust systems use two or three silencers. The silencer is called front silencer, intermediate silencer or rear silencer depending on the silencer's location.

The front silencer may fail due to fatigue cracking which can be caused by severe vibration. The front silencer can reach a temperature of 1000°C