A continuous sample of gas in the
stack is extracted by a dilution
probe by means of a critical orifice
and pneumatic ejector mounted
inside the probe.br>
Very low sampling rate, avoiding any clogging problem, and immediate
dilution at the sampling point.
Connection (up to 150m) by an uncomplicated unheated line.
Zeroing and calibration carried out at stack temperature and flow
conditions, checking simultaneously all elements of the system.
Multiprobes : from 1 to 4 probes connected to a single set of analyzers
Probe flue gas temperature standard : 400°C with quartz orifice : 600°C
Materials : special INCONEL, SS316 ; pyrex orifice, quartz orifice.
Probe length : standard 2 feet or longer upon option.
Dilution rate : 15/1 to 350/1 according to the critical orifice (sample flow rate from 20 ml/mn to 500 ml/mn)
Thermo Electron Corporation:
The Model 797 Dilution System performs four critical functions to prepare the sample from the stack, so that it can be measured accurately
and precisely by the analyzer. The system uses an air driven aspirator which extracts the sample from the stack. it is then passed
conseculatively through a coarse and fine particulate filter, a preselected glass or quartz critical orifice and diluted with the air
from the aspirator. This process has now reduced the dew point of the stack sample to below that of the ambient air.
Low extractive flow rates, promotes loong filter life
No need for heated sample line in most cases
Diluted sample is transported at positive pressure
Can be used in explosion proof areas
Easy dynamic in-situ calibration at total dilution system
Can be used with any exisiting ambient air analyzer
Manual or optional automatic blow back, backflushes coarse filter
Optional probe heater
Available in several corrosion resistant materials
Model 797 - Diluting Stack Sampler
The Out of Stack Dilution System is designed for emission monitoring applications where in-stack dilution probe system is impractical.
It uses the same basic sampling technology as our popular conventional in-situ dilution probe, yet all critical parts are mounted externally
for quick access and easy maintenance.
Designed for easy access to consumable and replacement parts
Heated sampling utilizes dual 400 W heaters
Easy dynamic in-situ calibration
Low sample flow rate utilizes bypass pump for sampling protection
Corrosion resistant design, available in 316L stainless steel, Inconel 600 and Hastelloy C-22
Selectable dilution ratios
Blowback part for manual or automatic operation
Model 797.381 - Out of Stack Diluting Sampler
The PRO902C External Low Flow Dilution Probe handles the toughest environments while offering significant advantages over typical in-stack dilution
probes. The Low Flow Probe meets EPA requirements as defined in 40 CFR 75 and 40 CFR 60 for continuous emissions monitoring, using dilution
extractive technology for dry basis measurement.
Probe Barrel: Corrosion resistant material. Consult TEI for lengths over 6'
Heated Filter: 0.1 micron glass fiber element, temperature controlled at 300°F (146°C)
Sample Orifice: Quartz glass, temperature controlled at 300°F (149°C)
Dilution Eductor: Torlon, Stainless Steel, or suitable material. Sample flow rate of approximately 100 cc/min., dilution air flow rate of
approximately 5 liters/minute, heated eductor temperature 300°F +/- 2°F (149°C), eductor vacuum greater than 15" Hg
Calibration Line: (1/4)" (0.64 cm) OD Teflon
Diluted Sample Dew Point: 0°F to -35°F (-18°C to -37°C) depending on dilution ratio
Dilution Ratios: Between 20:1 and 200:1 are standard
Instrument Air Requirement: Clean, dry air at -40°F (-40°C) dew point
PRO902C Modular External Low Flow Dilution Probe
The Model 83i consists of a dilution probe, inertial filter, and a proprietary dry converter/scrubber housed in an insulated NEMA 4X
stainless steel enclosure. The probe has been specifically designed for monitoring mercury emissions from coal-fired power plants and
waste incinerators. Artifacts due to interactions with the fly ash are minimized using a high-flow, sintered-metal inertial filter to
provide a particle-free, vapor-phase sample for analysis. Automated blow-back helps to ensure trouble-free continuous operation, and
all components exposed to sample gas are glass-coated to prevent reactions with mercury.
To prevent sample condensation, all key components (inertial filter, eductor, dilution module, and venturi) are further enclosed in a
heated aluminum cabinet. The converter/scrubber converts oxidized forms of mercury to elemental mercury while removing interfering gases
from the sample stream. Weighing only 92 pounds, the probe has been designed for easier maintenance and service. Latched panels are easily
removed from three sides of the probe allowing quick access to the interior. Inside, the components are so easily accessed that they can
be serviced or removed in a matter of minutes.
Model 83i Mercury Probe / Converter
Tyco Environmental Systems:
Dry thermo catalytic method, Dilution and
Conversion done at the Stack,
Sample dilution and scrubber which
eliminates interference from matrix gases
like SO2, HCl, NOx,
No risk of losing ionic mercury as only
Elemental Mercury is transported to the
Prepared for temporary or fixed installation
of an ionic calibration HgCl2
Hg(0) NIST traceable.
Operating Principle: A flanged probe is mounted at the stack. It
is connected to the analyzer unit with a
sample line that is heated to approx. 20-40
°C. The sample gas is drawn into the
dilution unit by an ejector pump, passing a
heated (500 °C) ceramic filter. A critical
orifice stabilizes the sample flow; a sensor
continuously controls the suction vacuum.
The sample filter is cleaned automatically.
A part of the diluted sample is passed
through the heated catalyst where the
different forms of mercury of the sample
are converted into the elemental form.
Ducon-MI SM4 Mercury CEMS