Presentation on theme: "Fuquay Varina, North Carolina 27526"— Presentation transcript:
1Fuquay Varina, North Carolina 27526 An Introduction toIsokinetic Source Samplingpresented by:Apex Instruments Inc.Manufacturer of Quality Sampling Equipment“Since 1988”204 Technology Park LaneFuquay Varina, North Carolinatel: fax:web:Apex Instruments Inc.
2Apex Instruments Inc. designs, manufactures, and markets equipment used for the collection of air samples from smoke stacks, chimneys, industrial ducts, and other process air streams.Apex Instruments Inc..
3Isokinetic Sampling Emission Data can be used: Government To provide data for determining appropriate emission limits.To provide data for determining compliance.To provide data for health risk assessments.To provide data for dispersion modeling.Isokinetic Sampling
4Isokinetic Sampling Emission Data can be used: Industry (continued)Emission Data can be used:IndustryTo evaluate air pollution control equipment.To provide information for design of new process and control equipment.To provide information on process operations.Isokinetic Sampling
5Isokinetic Sampling Isokinetic Measurement of Source Emissions: Particulate emissions from a source are sampled isokinetically using a US EPA Method 5 sampling train. The collected sample is analyzed to determine the pollutant concentrations.Isokinetic Sampling
6“ISOKINETIC” Isokinetic Sampling ISO = EQUAL + KINETIC = MOTION Isokinetic Sampling is an equal or uniform sampling of particles and gases in motion within the air stream.Isokinetic Sampling
7Basic Terminology Isokinetic Sampling Pmrs = Cs Qs CONCENTRATION (Cs) Quantity of pollutant per volume of effluent gasgrams / cubic meterSTACK GAS FLOW RATE (Qs)Volume of effluent gas per length of timecubic meters / hourPOLLUTANT MASS RATE EQUATION (Pmrs)Volume of pollutant gas per length of timegrams / hourIsokinetic Sampling
8Isokinetic Sampling Isokinetic Sampling is the application of five sampling methods developed by the USEPA plus the applicable method:Method 1 - Sample and Velocity Traverses from Stationary SourcesMethod 2 - Determination of Stack Gas Velocity and Volumetric Flow RateMethod 3 - Gas Analysis for Carbon Dioxide, Oxygen, Excess Air, and Dry Molecular WeightMethod 4 - Determination of Moisture Content in Stack GasesMethod 5 - Determination of Particulate Emissions from Stationary SourcesIsokinetic Sampling
9Partial Listing of US EPA Isokinetic Sampling Methods: Method 8 Sulfuric Acid Mist & SO2Method 12 Inorganic LeadMethod 13A FluoridesMethod Particulate Emissions (in stack filter)Method 23 Dioxin / FuransMethod 26A Hydrogen ChlorideMethod 29 Multi MetalsMethod 201A Determination of PM10 ParticulateMethod Semi Volatile CompoundsIsokinetic Sampling
10Method 1 Apex Instruments Inc. Sample and Velocity Traverses from Stationary SourcesApex Instruments Inc.
11Method 1 Method 1 is used to: 1. Select an appropriate sampling location2. Determine the required number of particulate sampling points3. Calculate the location of the sampling points within the duct.Method 1
12Ideal site should be at least 8 duct diameters downstream & 2 duct diameters upstream from any flow disturbance. Minimum distances are 2 duct diameters downstream and ½ duct diameters upstream from any flow disturbance.Method 1
13The number of sample points is dependent on the distance from any flow disturbance (measured in duct diameter).The following table is used for determining the required number of sampling points.Method 1
15The cross section is divided into the desired number of equal areas. Isokinetic sampling is conducted at discrete points in the cross-section of the duct .The following table is used for determining the location of sampling points.Method 1
16Location of Traverse Points in Circular Stacks Method 1
17The probe is marked to correspond to the appropriate sampling point using the table from Method 1.
18and Volumetric Flow Rate Method 2Determinationof Stack Gas Velocityand Volumetric Flow RateApex Instruments Inc.
19Velocity Traverses are conducted by measuring the stack gas velocity pressure (Dp) and stack temperature at each of the sample points determined by the Method 1 calculations.Method 2 is used to:Conduct a pre-test velocity traverseDetermine the effluent gas velocityMethod 2
20Pressure Components in Gas Streams a) Stagnation Pressureb) Static Pressurec) Velocity Pressure, (DP)Method 2
21Method 2 Type S (Stausscheibe) Pitot Tube Most commonly used in conjunction with Method 5 because of its:Compact size - fits in small portsDurability in designPlugging resistance in heavy particulateSensitivity at low velocitiesMethod 2
22Velocity measurements are conducted simultaneously during the sample period for the setting of the isokinetic sampling rate.Volumetric flows are adjusted for temperature, pressure, and gas molecular weight.Method 2
23for Carbon Dioxide, Oxygen, Excess Air, and Dry Molecular Weight Method 3Stack Gas Analysisfor Carbon Dioxide, Oxygen, Excess Air, and Dry Molecular WeightApex Instruments Inc.
24Method 3 is applicable for determining Dry Molecular Weight and excess air correction factors from fossil fuel combustion sources.Method 3Method 3
25Orsat AnalyzerA gas sample is collected in a tedlar bag and analyzed for CO2, O2 and sometimes CO.Method 3
26Dry molecular weight (Md) is calculated from the gas analysis results Md = (0.44 % CO2) (% O2) (% CO + % N2)Method 3
27Determination of Moisture Method 4Determination of MoistureContent in Stack GasesApex Instruments Inc.
28Moisture Content Procedure The water vapor is condensed in the impingers. The net gain is measured and the percent moisture is calculated.* Approximation methods are used to estimate percent moisture for setting isokinetic sampling rates.Method 4
29Determination of Particulate Emissions from Stationary Sources Method 5Determination of ParticulateEmissions from Stationary SourcesApex Instruments Inc.
30Method 5 Method 5 Principle Particulate matter is withdrawn isokinetically from the source and collected on a glass fiber filter maintained at a temperature in the range of oC.The particulate mass is determined gravimetrically after removal of uncombined water.Method 5
31Method 5 System Method 5 Components: Probe Assembly Heated Filter Compartment (Hot Box)Condenser Unit (Cold Box)Umbilical CableMetering Console with PumpMethod 5
32To obtain a representative sample of particulate matter from an air stream the velocity at the nozzle opening should be equal to the velocity of the approaching gas stream.Isokinetic Sampling
33100% Isokinetic100% isokinetic means that the velocity at the tip of the nozzle is equal to stack velocity. The true particulate concentration will therefore be obtained.Method 5
34Method 5 Under Isokinetic When the nozzle velocity is less than the stack velocity the results will be biased high due to the inertia of the large particles.Method 5
35Method 5 Over Isokinetic When the nozzle velocity is greater than the stack velocity the results will biased low since the larger particles break through the air stream and bypass the nozzle.Method 5
36Tools available for solving isokinetic rate equations include: Slide RuleComputer ProgramCalculatorMethod 5
37PRETEST PREPARATIONS Method 5 A tared filter is placed in the filter holderA known amount of water and silica gel is placed in the impingersA preliminary velocity determination is made to select the proper size nozzleSampling train is leak checkedMethod 5
39Method 5 Particulate Train Operation A compliance test will require at least three Method 5 sample runs.Each run must be for a minimum of 1 hour and 30 scf or other specified minimum time and sample volume.Sample train placed at first point and sample pump is startedMethod 5
40Method 5 Particulate Train Operation (cont.) Sample rate is adjusted to isokinetic after moving to each new sample point and any time the velocity pressure reading changes by more than 20%.The isokinetic rate setting is determined with a calculator or nomograph and established with a flowrate meter called an orifice meter.The sampling train is only shut down to move from port to port and at the end of the sample run.Method 5
41Method 5 Post Test Operation Upon completion of testing the sampling train must pass a leak test.The sample train is removed to a cleanup area that is free of dust and wind.The filter is removed from the container and placed in a sample container.Sample is removed from the sample exposed portions of the nozzle, probe liner and filter holder with acetone and placed in a sample container.Method 5
42AnalysisFilter is desiccated for a minimum of 24 hours and then weighed to a constant weight.Acetone sample rinse and an acetone blank are evaporated to dryness and weighed to a constant weight. The sample residue is weighed to a constant weight and the residue weight of the acetone is subtracted from the evaporated sample to yield the weight of the sample.Sum of the weight of the sample on the filter and in the acetone rinse is used to calculate the particulate emissions.Method 5
43Alternative Sampling Trains for Particulates Flexible Method 5Compact Method 5Method 17Method 201AApex Instruments Inc.
44Flexible Method 5 Uses flexible line between filter unit and condenser * Heated line may be required for some methodsAlternative Sampling Trains for Particulates
45Alternative Sampling Trains for Particulates Compact Method 5Includes:Heated Stainless Steel Filter UnitStainless Steel LinerFlexible Sample Line extensionCut-back Umbilical CableAlternative Sampling Trains for Particulates
46Alternative Sampling Trains for Particulates Method 17In-stack Filter ApplicabilityIn sources where particulate matter concentration is independent of temperature.Alternative Sampling Trains for Particulates
47Schematic of the EPA Method 17 Flex Sampling Train
48Method 201A PM10 Sampling Train Constant Sampling Rate Procedure (CSR) Alternative Sampling Trains for Particulates
49The PM10 Cyclone is built to EPA specifications for Method 201A testing and is designed for in-stack measurement of particulate matter equal to or less than 10 microns. The cyclone and in-stack filter assembly adapts easily to Method 5 probe assembly.PM10 KitMethod 201A