|
CECO Filters, Inc. has been providing fiber bed mist eliminators to the
Ammonium Nitrate Industry for more than 10 years.
Ammonium nitrate solution is produced by the exothermic reaction of nitric acid
and ammonia. This solution can be used as is, blended with other chemicals such
as urea melt, or converted to a solid form (generally "prills"). During production
of the solution and the conversion of the solution to a solid form, ammonium
nitrate mist is generated that cannot be released to the atmosphere or to bodies
of water.
Steam is produced by the exothermic reaction, separated from the ammonium nitrate
solution, and vented from the reaction vessel. Steam is also produced during the
concentration of the solution, a step which is necessary for the conversion to
solid prills. Both of these streams of steam carry ammonium nitrate mist that
often must be removed before the steam can be re-used in the process or disposed of.
During the conversion of the solution to solid prill form, a large volume of air
is used as a cooling medium. This air stream can carry a significant amount of
ammonium nitrate mist that must be removed before the air is released to the
atmosphere. While scrubbers can be used to capture a large portion of the ammonium
nitrate contained in the steam and air streams, scrubbing alone will not capture
the very fine sub-micron mist. CECO Filters' Fiber Bed Mist Eliminators employ the
Brownian motion mechanism to capture the sub-micron mist by diffusion filtering.
Use of the diffusion mechanism results in collection efficiencies of 100% for
particles larger than 3 microns and 99.5% for particles smaller than 3 microns.
CECO Filters' Fiber Bed Mist Eliminators have been successfully applied to
applications in ammonium nitrate production plants in the US and abroad. Since
Fiber Bed Mist Eliminators perform by coalescing the sub-micron mist into larger
droplets that drain from the filter, the ammonium nitrate mist can be recovered
and recycled to the process.
Media selection is a critical part of the filter design process. Proper selection
yields a filter that will provide many years of service. Improper selection will
yield a filter that fails prematurely incurring unnecessary downtime and cost. In
this regard, all ammonium nitrate production plants are not equal. Operating
environments of the reactor and concentrators can vary from plant to plant so there
is no universally economic media that can be installed in every plant. CECO Filters'
has solved filter life problems by replacing commonly used polyester media with
Teflon and CECO Filters' proprietary ChemResist media.
De-bottlenecking existing filter systems can be difficult and expensive if the
filter vessel must be modified to accept taller filters or a greater number of
filters. CECO Filters' Patented TWIN-PAKŪ has been used to retrofit existing
ammonium nitrate filter vessels, increasing throughput by more than 25% and
decreasing system pressure drop, without modification of the filter vessels.
If you have an ammonium nitrate mist problem, or if you are dissatisfied with
the life of your filter media,
call CECO Filters today.
|
