S-Series
Passive Diesel Particulate Filter (DPF)

 

Product Photo of S-Series of Diesel Particulate Filters (DPF)

  • Recognized and listed by the U.S. Mine Safety and Health Administration (MSHA)
  • Passive Diesel Particulate Filter (DPF) system that is ideal for mining application
  • Great at reducing deadly emissions, such as Carbon Monoxide (CO), Hydrocarbons (HC) and Particulate Matter (PM). Visible smoke is completely eliminated by the filter
  • This technology is pivotal in assisting retrofit compliance with the newly adopted MSHA rules regarding diesel particulate matter (DPM) emissions in underground mines
  • Available in two options: Cordierite or Silicone Carbide
  • Compact design with thermal insulation
  • Optional computerized controller with 3 customizable alarms and data logging capabilities
  • System maintenance intervals of 2000 to 6000 hours
  • Stainless steel housing, custom fit available

S-Series - Technology

Nett® S-Series diesel filters utilize cordierite or silicon carbide wall-flow monoliths to trap the soot produced by heavy-duty diesel engines. The cylindrical filter element consists of many square parallel channels running in the axial direction, separated by thin porous walls, as shown below.

Product Photo of S-Series of Diesel Particulate Filters (DPF) Air Flow

The channels are open at one end and plugged at the other, which forces the particle laden exhaust gases to flow through the walls. Gas is able to escape through the pores in the wall material. Particulates, however, are too large to escape and are trapped in the filter walls and in the inlet channels. A proprietary noble metal catalyst is coated onto the inside surface of the filter monolith. The catalyst lowers the soot combustion temperature allowing the filter to regenerate. The accumulated soot is oxidized in the filter during regular operation of the engine. For about 25-30% of the engine operating time, the exhaust temperatures must be at least 275-300°C (530-575°F) for proper filter regeneration when ULSD (ultra-low sulfur diesel) fuel is used.

The exact temperature requirements change with engine technology, with installations on older, dirty engines requiring higher exhaust temperatures for regeneration. For example, filters installed on older off-highway engines with high DPM emissions (e.g., >= 0.30 g/bhp-hr) may require temperatures of 325-400°C (615-750°F). The regeneration also depends on other factors, such as the vehicle duty cycle, filter sizing and type of diesel fuel used. ULSD fuel (S < 15 ppm wt.) is now widely available and should be used whenever possible with any diesel particulate filter.

Nett® diesel particulate filters are available with either cordierite or silicon carbide (SiC) substrates. Cordierite substrates perform satisfactory in most heavy-duty applications with high exhaust temperatures. However, in low-temperature applications which may experience “uncontrolled regenerations”, cordierite is more susceptible for damage from high temperatures, such as melting. Silicon carbide has higher maximum operating temperature limits and better durability in high temperature applications. Disadvantages of SiC include higher weight and higher cost.

S-Series - Performance

The soot filtration efficiency of the Nett® S-Series catalytic diesel filter increases with the soot loading in the unit. Even at low soot loads the filter efficiency exceeds 90% (blue line in Figure below). The visible smoke is completely eliminated by the filter, resulting in a dramatic improvement of smoke opacity readings.

Typical exhaust gas pressure drop on a properly regenerating filter is between 5 and 10 kPa (20-40" H2O). There is a relationship between the exhaust gas temperature and the filter pressure drop. Applications with higher exhaust temperatures regenerate better, accumulate less soot in the filter, and experience lower pressure drop. The filter pressure drop is also influenced by the engine-out DPM emissions. Dirty engines with high soot emissions require that more DPM is captured and oxidized in the filter, resulting in higher average soot loading and pressure drop. For this reason, filters are likely to work at a higher pressure drop when installed on high polluting engines.

S-Series of Diesel Particulate Filters (DPF) Performance

Gas Phase Performance

Due to the presence of the oxidation catalyst, reductions in Carbon Monoxide (CO) and Hydrocarbon (HC) emissions are also observed in the filter.  The gas phase performance of the Nett® S-Series filters is similar to that of a standard diesel oxidation catalyst, as illustrated in the figure below.

S-Series of Diesel Particulate Filters (DPF) Emission Reduction Graph

S-Series - Designs and Options

Standard models of cordierite and SiC diesel particulate filters are listed in Table 1 and Table 2, respectively. Filter sizing guidelines in the table are approximate. Sizing for particular engines and applications should be consulted with our office before ordering.

 

Nett Diesel Particulate Filters: Cordierite Substrates (SF)

S-Series of Diesel Particulate Filters (DPF) Filter List

Nett Diesel Particulate Filters: Silicon Carbide (SiC) Substrates (SX)

S-Series - Verification

This technology is pivotal in assisting retrofit compliance with the newly adopted MSHA rules regarding Diesel Particulate Matter (DPM) emissions in underground mines. It is the first legislation to control miners' exposure to diesel particulates in U.S. mines.

The coal mine rule prohibits heavy duty diesel equipment to emit levels exceeding 2.5 grams per hour of DPM with a phase-in schedule beginning May 21, 2001. The metal/non-metal (i.e. non-coal) mine rule establishes stringent DPM exposure limits effective July 19, 2001. Thousands of diesel engines in underground mines will be retrofitted with diesel particulate filters to comply with these regulations.

Two Nett® particulate filter technologies; cordierite, which performs in most heavy-duty applications with high exhaust temperature, accommodating engines from 15 to 450 kW in a single exhaust configuration; SiC (silicon carbide) has higher maximum operating temperature limits, accommodating engines from 13 to 206 kW in a single exhaust configuration, comply with the new MSHA diesel regulations for coal and metal/non-metal underground mines. Nett® particulate filters have been designed for heavy-duty mining equipment such as LHD loaders and haul trucks, which are the largest contributors to the total diesel particulate emissions in underground mines. The MSHA accepted filtration efficiency of Nett® filters for reducing these emissions is 85% and 87% for the cordierite and SiC technology, respectively.

The emission of DPM, commonly known as soot, is the current air quality concern in underground mining. Due to their sub-micron particle size, diesel particulates penetrate deep into human lungs contributing to numerous respiratory problems. Carcinogenic activity is also attributed to diesel particulates.

The use of diesel particulate filters is the only solution open to mine operators to meet these stringent regulations. Nett® particulate filters utilize ceramic wall-flow monoliths to trap DPM and offer unsurpassed filtration efficiency, typically in excess of 90%. The surface of the filter is coated with a proprietary catalyst, which has the ability to lower the soot combustion temperature. In contact with the catalyst, the collected diesel particulates burn out at temperatures found in the exhaust gases during regular operation of the vehicle. Thus, a self-regeneration of the filter is facilitated. Nett® filters work virtually maintenance-free on most heavy-duty diesel engines in underground mine applications.

Nett's particulate filter and other technologies complying with the regulations are listed on the MSHA website.

 

S-Series - Technology

Nett® S-Series diesel filters utilize cordierite or silicon carbide wall-flow monoliths to trap the soot produced by heavy-duty diesel engines. The cylindrical filter element consists of many square parallel channels running in the axial direction, separated by thin porous walls, as shown below.

Product Photo of S-Series of Diesel Particulate Filters (DPF) Air Flow

The channels are open at one end and plugged at the other, which forces the particle laden exhaust gases to flow through the walls. Gas is able to escape through the pores in the wall material. Particulates, however, are too large to escape and are trapped in the filter walls and in the inlet channels. A proprietary noble metal catalyst is coated onto the inside surface of the filter monolith. The catalyst lowers the soot combustion temperature allowing the filter to regenerate. The accumulated soot is oxidized in the filter during regular operation of the engine. For about 25-30% of the engine operating time, the exhaust temperatures must be at least 275-300°C (530-575°F) for proper filter regeneration when ULSD (ultra-low sulfur diesel) fuel is used.

The exact temperature requirements change with engine technology, with installations on older, dirty engines requiring higher exhaust temperatures for regeneration. For example, filters installed on older off-highway engines with high DPM emissions (e.g., >= 0.30 g/bhp-hr) may require temperatures of 325-400°C (615-750°F). The regeneration also depends on other factors, such as the vehicle duty cycle, filter sizing and type of diesel fuel used. ULSD fuel (S < 15 ppm wt.) is now widely available and should be used whenever possible with any diesel particulate filter.

Nett® diesel particulate filters are available with either cordierite or silicon carbide (SiC) substrates. Cordierite substrates perform satisfactory in most heavy-duty applications with high exhaust temperatures. However, in low-temperature applications which may experience “uncontrolled regenerations”, cordierite is more susceptible for damage from high temperatures, such as melting. Silicon carbide has higher maximum operating temperature limits and better durability in high temperature applications. Disadvantages of SiC include higher weight and higher cost.

S-Series - Performance

The soot filtration efficiency of the Nett® S-Series catalytic diesel filter increases with the soot loading in the unit. Even at low soot loads the filter efficiency exceeds 90% (blue line in Figure below). The visible smoke is completely eliminated by the filter, resulting in a dramatic improvement of smoke opacity readings.

Typical exhaust gas pressure drop on a properly regenerating filter is between 5 and 10 kPa (20-40" H2O). There is a relationship between the exhaust gas temperature and the filter pressure drop. Applications with higher exhaust temperatures regenerate better, accumulate less soot in the filter, and experience lower pressure drop. The filter pressure drop is also influenced by the engine-out DPM emissions. Dirty engines with high soot emissions require that more DPM is captured and oxidized in the filter, resulting in higher average soot loading and pressure drop. For this reason, filters are likely to work at a higher pressure drop when installed on high polluting engines.

S-Series of Diesel Particulate Filters (DPF) Performance

Gas Phase Performance

Due to the presence of the oxidation catalyst, reductions in Carbon Monoxide (CO) and Hydrocarbon (HC) emissions are also observed in the filter.  The gas phase performance of the Nett® S-Series filters is similar to that of a standard diesel oxidation catalyst, as illustrated in the figure below.

S-Series of Diesel Particulate Filters (DPF) Emission Reduction Graph

S-Series - Designs and Options

Standard models of cordierite and SiC diesel particulate filters are listed in Table 1 and Table 2, respectively. Filter sizing guidelines in the table are approximate. Sizing for particular engines and applications should be consulted with our office before ordering.

 

Nett Diesel Particulate Filters: Cordierite Substrates (SF)

S-Series of Diesel Particulate Filters (DPF) Filter List

Nett Diesel Particulate Filters: Silicon Carbide (SiC) Substrates (SX)

S-Series - Verification

This technology is pivotal in assisting retrofit compliance with the newly adopted MSHA rules regarding Diesel Particulate Matter (DPM) emissions in underground mines. It is the first legislation to control miners' exposure to diesel particulates in U.S. mines.

The coal mine rule prohibits heavy duty diesel equipment to emit levels exceeding 2.5 grams per hour of DPM with a phase-in schedule beginning May 21, 2001. The metal/non-metal (i.e. non-coal) mine rule establishes stringent DPM exposure limits effective July 19, 2001. Thousands of diesel engines in underground mines will be retrofitted with diesel particulate filters to comply with these regulations.

Two Nett® particulate filter technologies; cordierite, which performs in most heavy-duty applications with high exhaust temperature, accommodating engines from 15 to 450 kW in a single exhaust configuration; SiC (silicon carbide) has higher maximum operating temperature limits, accommodating engines from 13 to 206 kW in a single exhaust configuration, comply with the new MSHA diesel regulations for coal and metal/non-metal underground mines. Nett® particulate filters have been designed for heavy-duty mining equipment such as LHD loaders and haul trucks, which are the largest contributors to the total diesel particulate emissions in underground mines. The MSHA accepted filtration efficiency of Nett® filters for reducing these emissions is 85% and 87% for the cordierite and SiC technology, respectively.

The emission of DPM, commonly known as soot, is the current air quality concern in underground mining. Due to their sub-micron particle size, diesel particulates penetrate deep into human lungs contributing to numerous respiratory problems. Carcinogenic activity is also attributed to diesel particulates.

The use of diesel particulate filters is the only solution open to mine operators to meet these stringent regulations. Nett® particulate filters utilize ceramic wall-flow monoliths to trap DPM and offer unsurpassed filtration efficiency, typically in excess of 90%. The surface of the filter is coated with a proprietary catalyst, which has the ability to lower the soot combustion temperature. In contact with the catalyst, the collected diesel particulates burn out at temperatures found in the exhaust gases during regular operation of the vehicle. Thus, a self-regeneration of the filter is facilitated. Nett® filters work virtually maintenance-free on most heavy-duty diesel engines in underground mine applications.

Nett's particulate filter and other technologies complying with the regulations are listed on the MSHA website.