VANEC installed exhaust converter silencer

for for 4-speed engine

Installled VANEC exhaust converter silencer catalyst for

high-speed 4-cycle engine

A General Description of NSCR
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 A General Description of NSCR
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.

Additonal Resources
EPA Information and Links: 
•    National Emission Standards Hazardous Air Pollutants (NESHAP)
•    Reciprocating Internal Combustion Engines 
•    RICE NESHAP Proposed Rule Summary –Spark Ignited Engines
•    FINAL NESHAP Engine Rule Overview (Courtesy: BP America Production Company)

More About Catalyst Exhaust Silencers
“THREE -WAY” NSCR  for VOC, CO and NOx Reduction

Engine Operation Control Technology Target Pollutants
Rich-burn NSCR Catalyst (Three-way) NOx, CO, VOC
Stoichiometric NSCR Catalyst (Three-way) NOx, CO, VOC
Lean-burn Oxidation Catalyst (Two-way) CO, VOC
Lean-NOx Catalyst NOx, CO, VOC
SCR Catalyst NOx
Ceramic Coating NOx, CO, VOC
Model Grade Typical Overall D.I.L.
121 Industrial 20 dB
131 Industrial 20-25 dB
141 Hospital 30-35 dB
144 Critical 45 dB
154 Super Critical 50+ dB

VANEC Catalyst Exhaust Silencers are designed for use in suppressing the exhaust noise on any internal combustion engine and can be upgraded to act as a combination catalytic converter/silencer.  This upgrade is available on models 121, 131, 141, 144, and 154. The catalyst modules VANEC incorporates are engineered in various shapes and sizes. 

VANEC Advantages:
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

Catalyst Features:
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)

VANEC has the capabilities to retro-fit existing 2-cycle engines

manufactured by:
• Cooper-Bessemer
• Ingersoll Rand
• Worthington
• Dresser
• Clark
• Fairbanks Morse

VANEC also offers products suitable for new and existing 4-cycle engines manufactured by:
• Caterpillar
• Wartsila
• Waukesha
• Man Diesel

Typical Performance
NOISE REDUCTION - D.I.L. (Dynamic Insertion Loss)

Catalyst Exhaust Silencers​