Diesel Oxidation Catalysts

Nett Technologies’ Diesel Oxidation Catalysts (DOC) are catalytic converters designed specifically for diesel powered engines and equipment.

DOC’s reduce Carbon Monoxide (CO) and Hydrocarbons (HC) including the Soluble Organic Fraction (SOF) of Diesel Particulate Matter (DPM). DOC’s are simple, inexpensive, maintenance free and suitable for all types and applications of diesel engines.

M-Series – Performance

The M-Series Diesel Oxidation Catalyst (DOC) yields a balance of High Hydrocarbon, Carbon Monoxide, and Particulate Matter (SOF) conversion with low sulfate formation.

The exact emission performance depends on the catalyst size, exhaust temperature, and raw exhaust composition. A minimum temperature of about 180°C (360°F) is required for conversion. Best 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 sulfur content of the fuel. Achievable particulate matter reductions amount to 30-50%.

Catalyst Durability

The rugged construction of Nett Technologies’ exhaust purifiers, using either metallic or ceramic supports, provides excellent mechanical durability. The catalyst substrate is designed to last for the entire life-span of the engine. Good engine maintenance, however, is necessary to sustain the catalyst activity for similar period of time. The two major causes of catalyst deactivation are (1) high temperature and (2) poisoning.

The catalyst may suffer thermal degradation when exposed to temperatures above 650°C (1200°F) for prolonged periods of time. Diesel engines have intrinsically cool exhaust gases and thermal catalyst deterioration is not likely to take place under normal operating conditions. Catalyst overheating may occur only as a result of serious engine malfunction, such as leaking injectors, when unburned fuel is oxidized in the catalyst and excessive temperature rise is observed due to the exothermic reaction.

Several chemical elements have the ability to either selectively poison the catalyst or to mask the catalytic surface, thus, preventing the contact between exhaust gases and active catalyst sites. Substances to be avoided include phosphorus, zinc, heavy metals, lead, arsenic, vanadium, and silicone. Some of these elements (e.g., phosphorus) may be contained as additives in the engine lube oil. Low lube oil consumption and the use of low-phosphorus oils are guidelines for extended catalyst life. Leaks of lube oil into the exhaust system are very detrimental and can irreversibly deactivate the catalyst within a few hours or days.

M-Series – Designs and Options

M-Series DOC are available in two designs: universal fit (clamped or welded) and direct-fir replacement (of  the OEM muffler).

Direct-Fit Catalytic Mufflers

Nett Technologies has direct-fit catalytic mufflers available for thousands of models of construction equipment, forklift trucks and other diesel powered equipment. The pre-designed models are in-stock or can be built and shipped within a few days. Catalytic mufflers are available to replace the original muffler for any diesel application. The M-Series emission control catalyst is built into the muffler and is selected based on the size of the engine. Catalytic mufflers are guaranteed to be a exact-fit replacement for the original muffler. The emissions reduction performance of catalytic mufflers is also guaranteed, provided the engine is well maintained without excessive lube oil consumption.

Universal-Fit Catalytic Converters

Nett Technologies offers two universal-fit configurations for the M-Series catalytic purifiers, as shown in images below. The welded (one-piece) design is more compact and recommended for space-limited applications. The clamped design allows for easy removal of the center-body (catalyst) for inspection and cleaning, if required.

D-Series – Ceramic Diesel Oxidation Catalysts

Available in both universal and direct-fit, Nett Technologies’ D-Series (Ceramic) Diesel Oxidation Catalysts (DOC) are catalytic converters that were developed to operate within lower temperature ranges. D-Series Diesel Oxidation Catalysts (DOC) are maintenance-free, reliable and cost-effective emission control replacement solution for most original equipment (OE) mufflers

Features

• Ceramic DOC technology with Zeolites designed to extend the performance of diesel catalytic converters into the low-temperature range
• D-Series DOC is ideal for Off-road application (construction, mining, material handling, utility), On-road, Power Generation, Marine, Gantry Cranes and Locomotive industries
• Maintenance-free, reliable and cost-effective emission control solution
• Available in both universal and direct-fit designs (Nett Technologies has a database of over 10000 direct-fit muffler designs)
• Mufflers are built entirely from corrosion resistant materials: aluminized and stainless steels
• Installation time and cost are reduced to a minimum
• DOC Catalytic Mufflers match or surpass the original muffler in sound attenuation and back pressure characteristics with the addition of superior emissions performance
• Great at reducing deadly emissions, such as Carbon Monoxide (CO) and Hydrocarbons (HC)