“In few decades, US government scientists showed that underground miners exposed to high levels of diesel fumes have a threefold increased risk for contracting lung cancer compared with those exposed to low levels.”
Diesel exhaust is produced inside diesel engines. It is believed to contain toxic air contaminants and soot particles associated with negative health effects.
Diesel particulate matter (DPM) is the particulate component of diesel exhaust which includes diesel soot & aerosols.
The main particulate fraction of diesel exhaust consists of soot particles. Because of small size, inhaled particles may easily penetrate deep into the lungs. The rough surfaces of these particles make it easy for them to bind with other toxins in the environment, thus increasing the hazards of particle inhalation.
DPM is divided into three basic fractions:
i) Solids – dry carbon particles, commonly known as soot,
ii) SOF – heavy hydrocarbons absorbed and condensed on the carbon particles,
called Soluble Organic Fraction,
iii) SO4 – sulfate fraction, hydrated sulfuric acid.
The actual composition of DPM will depend on the particular engine and its load and speed conditions. “Wet” particulates can contain up to 60% of the hydrocarbon fraction (SOF), while “dry” particulates are comprised mostly of dry carbon. The amount of sulfates is directly related to the sulfur content of the diesel fuel.
The most effective filter is made of cordierite. Cordierite filters provide excellent filtration efficiency. Its cores look like catalytic converter cores that had alternate channels plugged – the plugs force the exhaust gas flow through the wall and the particulate collects on inlet face.
Micro-Soot soot filters traps and destroys the carbon particulates and soot produced by diesel engines. The filter features a proprietary coating that enables the device to burn the soot during normal operating condition, thereby regenerating it.
The Micro-Soot soot/diesel particulate filter can filter up to 95% of soot from exhaust gas. Even the tiniest of soot particles stick to the ceramic walls made of cordierite, Micro-Soot can eliminate the problem.
Three-way catalytic converters have the additional advantage of controlling the emission of nitrogen oxides (NOx) in addition of carbon monoxide (CO) & hydrocarbons (HC), in particular nitrous oxide, a greenhouse gas over three hundred times more potent than carbon dioxide, a precursor to acid rain and currently the most ozone-depleting substance.
Since 1981, "three-way" (oxidation-reduction) catalytic converters have been used in vehicle emission control systems in the United States and Canada; many other countries have also adopted stringent vehicle emission regulations that in effect require three-way converters on gasoline-powered vehicles. The reduction and oxidation catalysts are typically contained in a common housing, however in some instances they may be housed separately.
Regeneration is the process of removing the accumulated soot from the filter. In passive way, the catalytic coating on the ceramic soot filter material ensures that soot particulate are burned off even at low flue gas temperature (over 250°C)
As the best performance occurs at temperatures around 350°C-450°C, in active way, heater is recommended if the application with an average exhaust fume temperature lower than 350°C. However, the reduction of NOx will be adversely affected at the temperature over 250°C. Therefore, too high regeneration temperature is not recommended.
Installation of soot filter often raises concerns about increased exhaust back pressure. Most of the exhaust gas pressure drop over a soot filter tends to be caused by the accumulated soot, rather than the filter substrate. Problems arise if regeneration of the soot filter does not occur on a regular basis, causing its pressure drop to increase to unacceptable levels.
Our system has an self-operated bypass passage in order to let exhaust fume pass through in case of the filter blockage. The system automatically operated. No additional device or techniques required in order to solve the back pressure problem of exhaust system.
Flange connection of the system (soot filter & heater) enables easy installation. No special technique is required. And the stainless steel enclosure makes a good protection for the cordierite filters.
As the regeneration is automatically take effect, the system is maintenance free. However, for recommendation, ash build-up on filter is removed by cleaning the filter with vacuum or low-pressure compressed air.
To return the filter for a cleaning or for further details, contact Micro-Soot technical support.
541 S Glendora Ave
Suite F, Glendora, CA 91741
