Problem
A food products company that mixes various types of waxes and
other components to make the base for chewing gums was faced with
the issue of cleaning up a slightly odorous, visible emission being
exhausted from two of their process lines. The components of the
emission were hot particles of chewing gum and some volatile
organic compounds (VOC's). The particles would quickly clog a
conventional filter system or electrostatic precipitator, neither
of which could control the odor off the process line. In addition
to the emission problem, the condensation of the exhaust stream was
damaging the roof of the facility.
Action
After throrough technical evaluation, Anguil Environmental
Systems, INC. was selected and contracted to solve the visual, odor
and VOC problem.
Solution
The Anguil Self-Cleaning Ceramic Filter was recommended as the
ideal solution for processing the exhaust. In order to demonstrate
to the client that this was a viable solution, Anguil utilized
their portable self-cleaning ceramic filter test unit before any
purchase decisions were made. During the test, the process lines
were run through the ceramic filter in two modes, hot and
cold.
First, the system was run in the hot mode with a gas burner firing
continuously at 400º-500ºF heating up the process air. The once
visible plume disappeared as it passed through the ceramic filter
and catalyst module. Second, the ceramic filter was used without
heat, and again, the visible plume disappeared as it passed through
the ceramic filter and catalyst module. Twenty-four hours of
production were run across the ceramic filter without heat and the
visible emission was acceptable from a customer and environmental
regulation standpoint. However, when utilizing a cold process
stream, particulate matter accumulated on the ceramic filter which
had to be periodically cleaned by firing the burner. When the
cleaning cycle began after the two shifts, a dense white plume was
emitted for 90 seconds while the filter element was burned clean.
The customer, a food products company, felt that this emission
level was not acceptable so they decided the continuous hot running
ceramic filter would better fit their needs. It should be noted
that for certain operations with visible emissions, the pulse
cleaning mode may be acceptable. Many local authorities allow
companies to discharge up to five minutes per hour without
control.
After the customer determined that the ceramic filter would solve
their problems, Anguil proceeded to manufacture and install a 1,000
SCFM (1,577 Nm3/Hr) ceramic filter unit. The unit was used to
process the exhaust from two process lines. One of the more
significant benefits to the company was Anguil's ability to reduce
the air volume from the processes. Initially, the two gum-based
mixers each had a 3,000 SCFM (4,731 Nm3/Hr) high volume, low static
pressure fan that was exhausting to atmosphere. Tight covers on the
mixers minimized the escape of odor into the mixing room. With the
close capture hoods it was possible to reduce the air volume from
6,000 SCFM (9,462 Nm3/Hr) exhaust to 1,000 SCFM (1,577 Nm3/Hr)
exhaust from the two process lines. The net air volume reduction of
82% reduced both the capital cost and the operating cost of the
system.
In order to guarantee continuous production in the event of a
burner failure, Anguil installed a bypass equipped with
conventional roughing filters. The exhaust fan was equipped with an
inlet vane control to vary the air volume if only one process line
was being used. The control panel was outfitted with a
user-friendly PLC first out detection system. The entire ceramic
filter system was mounted in a light-weight enclosure to allow for
roof mounting without significant structural modifications to the
building. Growth capacity was accommodated in the gas burner and
the fan section, allowing for the addition of future operations.
Anguil's system engineering provided their client with a solution
to their compliance need at reduced air volume and reduced
cost.