Perma Pure Baldwin-Series 10410 - Manual (Page 5)

Section C: Principle of Operation 5
C: P
RINCIPLE OF
O
PERATION
Thank you for purchasing a Baldwin™ Model 10410 SO
3
Aerosol Removal Series
Thermo-Electric Cooler. Perma Pure’s Baldwin SO
3
Aerosol Removal Series
Thermo-Electric Coolers are specifically designed to remove SO
3
and condensate
from sample streams in high ambient temperature & high water volume applications.
Each model in our SO
3
Aerosol Removal Series feature an oversized heat sink and
high performance thermoelectric devices for high heat removal capacity. Heat sinks
used in Baldwin-Series Thermo-Electric Coolers are made out of high heat transfer
extruded aluminum with large 3/4" thick end plates. Each model also incorporates a
special controller specifically designed to run at high ambient temperatures.
Perma Pure’s SO
3
Aerosol Removal Series is specifically designed for gas sample
applications with relatively high SO
3
content (>10 ppm). The SO
3
Aerosol Removal
Series has special timing circuits that alternate freeze and thaw the precisely packed
heat exchangers. Before an active heat exchanger thaws, the alternate active heat
exchanger reaches the -7
qC set-point to ensure uninterrupted operation. This sub
zero temperature forms a thin ice layer that captures and removes SO
3
aerosol from
the sample stream.
The two heat exchangers located on the left side of the sample cooler are connected
in series. The sample stream first passes through an inactive (i.e., not cooled with
thermoelectric elements) Durinert
®
coated heat exchanger used for removing gross
amounts of water. The sample then passes to an active Durinert
®
coated heat
exchanger. The exit dew point from this heat exchanger is controlled to +4°C,
thereby reducing the moisture concentration to less than 1%. The gas sample then
flows through the gas sample pump where it first alternately passes through the
freezing Kynar
®
packed heat exchangers, located on the right side of the cooler,
then to three-way Teflon
®
solenoid control valve, and finally to the remainder gas
sampling system. Condensate is pumped from each heat exchanger by a dedicated
peristaltic drain pump head.
The process of sampling combustion product stack gas or exhaust from internal
combustion engines requires a method to remove the moisture from the sample,
without removing the gas components of interest. The Baldwin-Series Thermo-
Electric Cooler is an ideal way to decrease the dew point of combustion gases to a
repeatable, stable, constant low dewpoint. The Baldwin-Series cooler prevents
water condensation in sample pre-filters, sample pumps, and gas analyzers. For
gas analyzers where water vapor is an interferant, a stable, repeatable dewpoint
becomes a part of the gas analyzer performance specification. Baldwin coolers
provide this constant low water concentration, resulting in an accurate component
gas measurement.
All Baldwin-Series coolers use thermo-electric elements (Peltiers) to cool the sample
gas to the desired dew point temperature. A thermo-electric cooler is best illustrated