The purpose of a diesel particulate filter (DPF) is to separate diesel particulate matter from an exhaust gas stream. This is trapped in the filter media, but obviously there is a limit to how much can be trapped before the filter becomes blocked.
The simplest type of DPF is disposable, however since the quantity of diesel particulate matter produced by even a modern engine is quite high, disposable filters need replacing after a few tens of hours, which is expensive and inconvenient.
More advanced filters can be cleaned, which is known in the industry as ‘regeneration’. Regeneration involves oxidising the diesel particulate matter trapped in the filter. This is a temperature-dependent process, and cleanable filters are classified into two categories: passive and active. Passive filters rely on the heat of the exhaust gas to clean them, whilst active filters have an external heat source. Many filters are designed so that they regenerate passively most of the time, but with active regeneration as a back-up strategy. Active regeneration can be triggered either manually or automatically.
In all but the simplest cases, diesel particulate filters are not a component but rather a system, incorporating electronic controllers, sensors, and other components which ensure that they regenerate reliably.
Designing a diesel particulate filter system is a complex task, and if it is done wrong the filter will block up and stop (or damage) the engine, which is especially unwelcome in the power generation or marine sectors. Blackthorn has 20 years’ experience in this field which has given us a thorough understanding of both the technologies and the needs of our customers, enabling us to supply DPF systems which are effective and reliable.