Filters with By-pass
Diesel particulate filters accumulate soot, which leads to increased exhaust backpressure. There always needs to be at least one strategy for cleaning out this soot, otherwise the exhaust backpressure will reach the point where it stops or damages the engine. This cleaning process can be initiated either manually or automatically and either of these approaches is satisfactory 99% of the time. However in some critical applications, such as hospital generators, 99% reliability is not good enough.
The best way to design diesel particulate filters for critical applications is to make them fail-safe, in other words to ensure that the engine keeps running even if the filter gets blocked. The answer is a filter system incorporating a by-pass with motorized valves connected to a pressure sensor. There are two versions of this system. In the first, the by-pass leg has no filter in it, whilst in the second, both legs have a filter in them.
The filters are cleaned either whilst the generator is stopped, or whilst the leg in which the filter is installed has been by-passed. Cleaning is achieved using electrically-heated air.
Blackthorn can design and supply fail-safe diesel particulate filter systems for engines of any size.