| |
Metex has been
a supplier to the automotive and small engine industries for
over 40 years supplying the first knitted wire mesh supports
for the monolithic catalyst element in an automotive converter
assembly. Metex coated exhaust catalysts continues our long standing
tradition of innovation by offering specialty catalysts and mufflers
using knitted wire mesh coated with a variety of precious Platinum
metals.
Our knitted wire mesh product delivers durability, reduced
emissions and decreased backpressure and is cost effective when
compared to other substrates. Our designs are customized in a
variety of sizes and loadings to exceed the expected performance
of your system and meet all applicable emissions and conversion
requirements.
Metex mesh substrates reduce oxides of nitrogen (NOx)
as well as carbon monoxide (CO), hydrocarbons (HC) and particulate
matter (PM).
Reduced Emission Pollutants
Emissions are unhealthy and contribute
to air pollution when not properly controlled. Strict emission
reductions are an
increased concern in small two stroke and four stroke engines
and targeted by the EPA for reduction. Small engines such as
those used in lawn and garden equipment — lawn mowers,
tractors, trimmers, edgers, leaf blowers, and chain saws, as
well as motorcycles and mopeds, are a significant source of
air pollution. These gas and diesel fuel engines emit pollutants
such as hydrocarbons (HC), nitrogen oxides (NOx) and carbon
monoxide (CO).
Metex mesh catalyst designs have successfully
worked in reducing emissions and have replaced standard ceramic
and foil substrates due to its cost effective performance and
simplicity.
Knitted Wire Mesh—The Cost-effective Alternative to Ceramic and Metallic Foil Substrates
The typical ceramic and metal foil substrates are flow-through designs with welldefined
channels parallel to the flow axis of the exhaust gas. Thus it is possible
for portions of the exhaust gas to pass through these channels and not come into
contact with the channel walls or the precious metal. In order to prevent this,
ceramic and metal foil substrate manufacturers increase the cell density (lower
the channel opening) and increase the amount of precious metal loading on the
substrate. Both of these options increase complexity and cost.
With a knitted wire mesh substrate, however, the wire is randomly dispersed
around the substrate so there are no direct passages along the axis of the flow.
This ensures that all of the exhaust gas passing through the converter will make
contact with the wire mesh substrate and the precious metal. As a result, the surface
area (and precious metal loading) of our mesh substrate can be lower than
that of a similar performing ceramic or metal foil substrate. Result: lower cost.
In small engine applications, Metex has developed coated substrates for richburn
and lean-burn applications. In particle-trap applications, the knitted wire
mesh substrate in a particulate has the advantage of being very difficult to clog
with soot due to the way a typical soot trap works. The standard ceramic trap is
almost identical to a converter substrate with the exception that the channels
are alternately closed on one end. The exhaust gas travels through one open
channel, but since it is blocked on the end, the gas must pass through the wall of
the channel and into the adjacent channel where it then travels out the opposite
end.
Since the pores in the channel walls must be very small to prohibit the large
soot particles from passing through, they clog very easily. As in the case with
converter substrates, the mesh substrate for a soot trap relies on the soot particles
impacting with the mesh and being retained by the catalyst material (precious or
rare earth materials) rather than “filtering” the soot particles through a small
pore. Although the main advantage is the anti-clogging nature of the mesh,
there are also potential savings in precious metal due to lower substrate loading.
Product Benefits
- Cost effective
- Loadings with proprietary
precious metals
- Increased mechanical
and thermal shock
resistance
- Noise reduction
- High efficiencies with
decreased backpressure
- Easy to install in existing
or new muffler
assemblies
- Customized designs to
meet your performance
and space requirements
- Experienced R&D services
to optimize catalyst
design and coating
Typical Applications
- Motorcycle
- Mopeds
- Lawn and garden
equipment
- Small engine
- Automotive
- Snowmobiles
- ATVs
- Personal watercraft
- Marine engines
Custom Designed to Enhance Performance
Our engineering staff will work with you from initial inquiry through prototype
development and production to develop the proper mesh design and loadings
that will effectively meet your compliance and cost requirements.
|
