A
Leader in Silencing for Industry
“THREE -WAY” NSCR for VOC, CO and NOx Reduction
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Engine Operation |
Control Technology |
Target Pollutants |
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Rich-burn |
NSCR Catalyst (Three-way) |
NOx, CO, VOC |
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NSCR Catalyst (Three-way) |
NOx, CO, VOC |
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Lean-burn |
Oxidation Catalyst (Two-way) |
CO, VOC |
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Lean-NOx Catalyst |
NOx, CO, VOC |
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SCR Catalyst |
NOx |
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Ceramic Coating |
NOx, CO, VOC |
An NSCR system reduces NOx, CO, and hydrocarbon (VOC) emissions from a rich-burn engine when the air-to-fuel ratio is near stoichiometric (14.7 to 1). When a rich-burn engine is tuned strictly for performance, oxygen is in the 1% to 3% range.
At this AFR, CO and hydrocarbon emissions are low and NOx is high, because the engine is running hot for maximum efficiency. When using an NSCR system, the engine must be operated richer so that an increase in reducing agents (CO and hydrocarbons) occurs. In addition, the NSCR must be operated at a temperature adequate to accomplish NOx reduction, typically at least 750ºF. The catalyst is designed to produce the following reactions:
NOx + CO --» N2 + CO2
NOx + CH4 --» N2 +CO2 + H2O
NOx + H2 --» N2 + H2O
If there is too much oxygen in the exhaust, the preferential reaction in the catalytic converter is the oxidation of CO or hydrocarbon rather than the reduction of NOx. Thus, with NSCR, the oxygen concentration should always be less than 1%, and preferably under 0.5%. The air-to-fuel ratio controller uses an oxygen sensor placed in the exhaust stream near the catalyst inlet as a feedback signal to keep the AFR at the optimum set point. The sensor is particularly sensitive to oxygen concentrations below 1%.
Some conditions that can reduce catalytic activity over time are thermal degradation, poisoning, or masking. Thermal degradation is caused by sintering of the wash coat, which closes the pores, thereby reducing catalyst surface area. Sintering can occur slowly over time, or quickly if the catalyst is operated at a temperature that is too high. Too much sulfur or phosphate in the engine oil or fuel can cause poisoning of the catalyst. Masking occurs when soot is deposited on the catalyst because the engine is burning oil.
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Air Toxics
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RETRO-FIT OF EXISTING 2 CYCLE ENGINES:
• COOPER-BESSEMER
• INGERSOLL RAND
• WORTHINGTON
• DRESSER
• CLARK
• FAIRBANKS MORSE
• EMD
NEW & EXISTING 4 CYCLE ENGINES:
• CATERPILLAR
• WARTSILA
• WAUKESHA
• MAN DIESEL
NOISE REDUCTION - D.I.L. (Dynamic Insertion Loss)
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Model |
Grade |
Typical Overall D.I.L. |
| 121 | Industrial | 20 dB |
| 131 |
Industrial Residential |
20-25 dB |
| 141 | Hospital | 30-35 dB |
| 144 | Critical | 45 dB |
| 154 | Super Critical | 50+ dB |
• Optimal conversion efficiencies with reduced catalyst volume.
• Heavy-duty stainless steel modules.
• Cell densities up to 700 cpsi.
• Lowest pressure drop for the most surface area.
• Individually mounted module design.
• Broad operating temperature range (350°F to 1200° F).
Typical Catalyst Engine Silencers:
• Custom designed for ease of field maintenance with
low chamber element/module access.
•Proven ability to meet noise and emission specifications
in a combined unit.
•Designed to mount on existing foundation and exhaust
center lines.
VANEC incorporates catalyst modules in various shapes and sizes
engineered by ™PCA, Inc.® and manufactured by ™EmeraChem LLC.®
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Pollution Control Associates: (For Lean Burn Engines.) |
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Made In
USA
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