Hybrid Silicon Carbide System

Blackthorn can supply a diesel particulate filter system incorporating a silicon carbide filter element and making use of both passive and active regeneration strategies.

Fuel-borne catalyst is dosed into the fuel feed line at a controlled rate of about one litre for every 1500 litres of fuel, and this serves to lower the combustion temperature of the DPM to about 350C. The system has an ECU which continually monitors exhaust backpressure and uses this information to adjust the dosing rate if necessary. This aspect of the system is protected by a patent owned by Innospec, the makers of Satacen 3 fuel borne catalyst, but no infringement of the patent will occur as long as only their fuel-borne catalyst is used. The active part of the system is equally innovative. Two glow plugs (the same as are used for cold starting) are installed directly in front of the filter, and during normal operation these become coated with DPM. When one of the glow plugs is switched on, this DPM starts to burn and the heat produced by this ignites the DPM residing in the filter. The reason that there are two glow plugs is that these are activated alternately, which allows more time for a layer of DPM to build up on each one. In addition to controlling the dosing pump and the glow plugs, the ECU also stores data about operating conditions and conveys information if necessary to an LED mounted in view of the driver.

The ECU is housed in a rugged IP65 plastic case and the system can be powered from either 12 or 24 volts. It has been fully approved for electromagnetic compatibility by the Vehicle Certification Agency and, unlike some other systems, is not sensitive to the sulphur content of the fuel.

Maintenance consists of topping up the fuel-borne catalyst tank and periodically removing ash from the filter. The need for this is highlighted by a signal sent to the LED in the drivers cab, although a cleaning interval of about 1000 hours is typical.

A range of fuel-borne catalyst tanks is available to suit various engine sizes and space constraints. One-off requirements are usually installed by our own engineers using a standard kit of parts which is customised on site to suit the application, but for fleet and OEM orders we can supply the system with a bespoke fitting kit, wiring harness and instructions which enable the customer’s own staff to complete the installation efficiently.

Schematic diagram of hybrid silicon carbide filter system
(Diagram: Schematic diagram of hybrid silicon carbide filter system)