Norman G Clark has introduced Nett Technologies’ diesel catalysts.
The M-series diesel oxidation catalyst yields a balance of high hydrocarbon, carbon monoxide, and particulate matter (SOF) conversion with low sulfate formation.
Nett Technologies offers several D-series catalyst coatings which are engineered for different applications.
D-series catalysts incorporating sulfate suppressants for good high temperature DPM conversion, suitable for heavy duty applications, are also available.
The exact emission performance of the catalyst depends on the catalyst size, exhaust temperature, and raw exhaust composition.
A minimum temperature of about 180°C (360°F) is required for conversion. Optimum catalyst performance occurs at temperatures above 250-300°C (480-570°F) when the conversion of carbon monoxide exceeds 90%.
Conversion of diesel particulate matter in the catalyst depends on the composition of the particulates and the sulphur content of the fuel. Achievable particulate matter reductions amount to 30-50%. Low sulphur diesel fuel is strongly recommended for optimum catalyst performance.
The M-series diesel exhaust purifiers utilises metallic monolith catalyst supports. The supports are made with a corrugated, high temperature stainless steel foil. Packages of several foil layers are fitted in stainless steel housings and secured in place by stainless steel rings.
A special herring-bone foil corrugation pattern creates a mixed flow cell structure. Exhaust gases are forced into the turbulent flow regime resulting in better contact between gas and catalyst, enhanced mass-transfer conditions, and higher conversion efficiency.
The catalyst is deposited onto the foil prior to forming the substrate. A special foil washcoating process provides good control of washcoat uniformity, adhesion, and efficient catalyst use.
Thick washcoat concentrations in cell corners which are inherent for other designs of metallic substrates completely disappear with the precoated foil technology.