Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.


  1. Advanced Patent Search
Publication numberUS3841145 A
Publication typeGrant
Publication dateOct 15, 1974
Filing dateAug 3, 1973
Priority dateNov 15, 1971
Publication numberUS 3841145 A, US 3841145A, US-A-3841145, US3841145 A, US3841145A
InventorsR Boubel
Original AssigneeRader Companies
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method and apparatus for measuring particulate emissions in gas flow
US 3841145 A
A stack sampler for collecting particulate samplings in gaseous emissions includes means to match the volume rate of flow through the sampler to the flow in the stack. Filter means removably disposed in the sampler are adapted to collect particulate matter from the gaseous emission during the isokinetic flow which is obtained. The high volume capacity of the sampler permits accurate samples to be obtained during short sampling periods.
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

United States Patent [191 Boube l METHOD AND APPARATUS FOR MEASURING'PARTICULATE EMISSIONS IN GAS FLOW [75] Inventor: Richard W. Boubel, Corvallis, Oreg.

[73] Assignee: Rader Companies, Inc., Portland,


[22] Filed: Aug. 3, 1973 [21] Appl. No.: 385,310

Related US. Application Data [63] Continuation of Ser. No. 198,779, Nov. 15, 1971,


[52] US. Cl 73/28, 55/270, 55/274, 55/417, 55/418, 55/467, 55/493, 55/501,

55/503, 55/DIG. 34, 73/42l.5 R, 251/305 [51] Int. Cl ..B0ld 53/30 Field of Search 55/18, 20, 21, 270, 274, 55/267, 493, 502, 503, 417, 418, 467, 501,

DIG. 34; 73/23 R, 28, 211', 21.2, 421.5 A,

[56] References Cited UNITED STATES PATENTS 310,157 1211884 Von Weisenflue 55/493 1,296,922 3/1919 Clairmont 251/305 1,775,127 9/1930 Hunt 251/305 X 2,074,481 3/1937 Macmullen et al. 55/503 X 2,285,829 6/1942 Maage, Jr. 251/305 X 2,408,661 10/1946 Lee 73/212 2,452,224 10/1948 Collett, .lr. 73/421.5 R 2,613,454 10/1952 White 55/274 X 2,722,998 11/1955 Hall 55/270 X .14 1 Oct. 15, 1974 3,672,225 6/1972 Louis 73/421.5 R

FOREIGN PATENTS OR APPLICATIONS 927,271 5/1963 Great Britain 73/42l.5 A

1,405,386 5/1965 France 73/28 158,137 6/1962 U.S.S.R 73/28 OTHER PUBLICATIONS German Printed Applicaton No. 1,126,649, Printed 3-29-62, (1 sheet drawing, 2 pages specification). Solnick R. L., Sampling Particulate Matter," The Oil And Gas Journal, Oct. 15, 1956, Pages 120-124.

Primary Examiner-Dennis E. Talbert, Jr. Attorney, Agent, or Firm-Klarquist, Sparkman, Campbell, Leigh, Hall & Whinston [5 7] ABSTRACT A stack sampler for collecting particulate samplings in gaseous emissions includes means to match the volume rate of flow through the sampler to the flow in the stack. Filter means removably disposed in the sampler are adapted to collect particulate matter from the gaseous emission during the isokinetic flow which is obtained'The high volume capacity of the sampler permits accurate samples to be obtained during short sampling periods.

'2 Claims, 4 Drawing Figures This is a continuation of application Ser. No. 198,779

filed Nov. 15, 1971 now abandoned.

BACKGROUND OF THE INVENTION With the passage of the Federal Clean Air Actof 1967, came the establishment of regions, ambient air standards and emission standards. The formation of the regions was done by the federal government. The ambient air standards were established'a't hearings during which much data from various air sampling networks was reported. I

Emission standards are now being set after applying mathematical models to find the emission levels necessary to comply with the ambient air standards already adopted. Industries, municipalities and all citizens will be expected to comply with the emission standards. This will result in a massive enforcement effortfor all pollution control agencies. In order for'this enforcement to be effective, the agencies, industries, consultants, etc. must initiate large scale'sampling program to obtain the required emission numbers.

Properly to sample just one of the emissions, i.e., particulate matter, has heretofore required at'least one man week per source test. 2 man weeks have been required when the test was conducted with'presently many different elements in series, such as-probes, cy-

clones, filters, thimbles and impingers." Each element had to be subjected to aseparate analysis which took considerable laboratory time.

Furthermore, apparatus which collect particulate .in

several different train components in series cannot be used to obtain a'particle size analysis. When using such apparatus, it has been necessary to run a separate sample for size analysis.

Presently available apparatus has also been limited to very low flow rates. Apparatus utilizing impingers and a wet test gas meter as part of the device have been limited to flows less than l cubic foot per minute. This means that the source must be sampled for a very long period of time if a large enough sample is to be obtained for accurate gravimetric analysis.

Many processes that must be sampled do not operate continuously for a long enough time to be sampledwith such a low flow rateapp ara tus. For example, an asphalt plant dryer may only operate for 10 minutes at a time and then shutdown for 2 hours. If the sample isto be valid, it must be taken during one operating cycle and in as short a time as practical;

Low flow rate samplers take such a long time to obtain a sample that they integrate the sample over a 'considerable time period. Where a boileris changing load,

time samples, the mean and standard deviation may be determined to indicate what portion of the time the.

source would be legal or illegal. Insufficient data also hampers enforcement actions'against sources having large gas flows.

Furthermore, much apparatus heretofore available is developed under laboratory conditions and are awkward to use in the field. I

It is thus the primary object of the present invention to provide a high volume sampler that can take an accurate sample in a relatively short period of time.

It is a further object of the present invention to provide such a sampler that can takeja' reliable sample from a variety of sources cheaply, quickly, and under field conditions.

ltis a still further object of the present invention to provide such a sampler that will take a sample under 'flow'conditions matched to those in'the source, i.e.,

under isokinetic conditions.

SUMMARY OF THE INVENTION The sampler of the present invention comprises a generally'cylindrical sampler tube, inlet nozzle means disposed at one end of the tube and adapted for insertion into a stack or like conduit through which a gas is flowing, and means to measure-the volume rate of gas flowing through the stack. A flow measuring orifice is disposed in the tube, and means are associated with the orifice for measuring the volume rate of gas'passing through the tube. 1

Suction pressure applying means are provided in communication with the downstream end of the tube. Control valve means are disposed in the tube between the orifice and thesuction pressure applyingmeans, the control valve means being adapted to adjust the volume rate of gas passing through the'tube to be equivalent to the velocity of gas flowing through the stack.

Filter means are removably disposed in the tube upstream of the orifice for collecting particulate matter from the gas while the volume rate of gas passing through the tube-is matched to the velocity of gas flowing through the stack, i.e., under isokinetic conditions. This matching of the gas flow through the sampler to the gas flow in the stack permits a more accurate particulate sample to be obtained.

The method of the invention comprises measuring the-velocity of gas flowing in a stack or like'conduit, in-

end of the sampler to cause the portion of gas flowing through thesample'r tobe the kinetic equivalent of the I velocity of gas flowing through the stack, and collecting particulate matter on a filter placed in thesampler for for example, a sample should be taken rapidly in order v to achieve a valid emission datapoint.

Furthermore, it is preferable statistically to take several short time samplesof a given volume than to take only one sample of the same volume. With several short a predetermined time-under the isokinetic conditions achieved. v

BRIEF DESCRIPTION'OF THE DRAWINGS FIG. 1 is a side view of a sampler in accordance with DESCRIPTION OF THEPREFERRED EMBODIMENT ent invention is made of 2-inch aluminum tubing onesixteenth inch thick having a 1% inch inner diameter and forming an inlet nozzle '12 and a main body portion 13, a filter housing 14 being disposed intermediate the ends of the body portion 13. A pitot tube 15 is removably attached to the side of the inlet nozzle12 and the upstream portion or inlet section 16 of the body portion 13, total and static pressure lines 17 and 18, respectively, being connected to a first Magnehelic pressure gauge 20 mounted on a control panel 21 on the downstream portion or control section 22 of the body portion. 3

An orifice meter 23 in the form of 1% inch diameter sharp-edged orifice 24 is disposed intermediate the control section 22, pressure connections being provided on both sides thereof for attachment to the pressure and suction posts respectively of a second Magnehelic pressure gauge 25 also mounted on the control panel 21. i

A suction blower 27 is provided separate fromthe main body portion 13, being connected to the downstream end thereof by a length of flexible hose 28. A butterfly control valve '30 is disposed in the control section 22 downstream of the orifice meter 23f0r controlling the rate of flow through'the sampler.

A temperature gauge 31 insertable in a fitting 32 in the control section 22 is also mounted on the control panel 21 for determining the temperature of the flow through the control section 22. t

The inlet nozzle 12 is elbow shaped for ready insertion in a stack or like conduit and, asmentioned hereinabove, ismade of two inch diameter aluminum tubing, one-sixteenth inch thick, having an inner diameter of 178 inches. lts downstream end 33 is attached to the upstream end 34 of the inlet section 16 by a clamp 35' and sleeve 36.

The pitot tube 15 is mounted exteriorly of the nozzle 12 and the inlet-section 16 and is provided with total and static pressure linesl7 and 18 for connection to the pressure gauge 20. The latter is mounted on the control panel 21 attached to the control section 22, Gauge 20 has a range of zero to four inches'of water.

pin 42 at theirlower ends. The upper ends.43 are closed by means of pivotal catches 44. A rubber support gasket'45 is mounted in the downstream end ofthe section and an aluminum framed screen support 47 is positioned in the downstream section 41 as shown. A

' sheet of filter.material 48 is inserted in the housing 14 on the upstream side of the screen support 47, being easily inserted and removed when the'housing is open.

The downstream end of the section 41 is connected to the control section 22 of the sampler by means of wing nuts 49, as shown. The orifice plate 23 is welded to the downstream end of the control section 22 as shown, and a final tube section 50 is provided. Pressure connections 51 and 52 consisting of taps and hose fittings are positioned on both sides of the orifice plate 23 and are connected to the pressure and suction posts,

respectively, of the second Magnehelic gauge 25 by means of rubber tubing. The gauge 25 has a range of zero to two inches of water.

The one-sixteenth inch thick aluminum circular butterfly valve 30 is mounted on a rotatable shaft 52 by means of screws 53. The shaft 52 is joumaled in the tube section 50 adjacent the downstream end thereof and .is provided with a knurled knob 54 at one end and spring-loaded friction washers 55 at the other for retaining the valve 30 in any desired position.

The suction blower 27 communicates with the sampler through the length of flexible hose 28, being sepa- OPERATION Before using, the sampler 10 is thoroughly cleaned with a suitable solvent to remove any residual particulate matter. Filter papers 48 for a test are conditioned atroom temperature in a desiccator for at least 12 hours before initial weighing.

The sampling procedure at a source comprises measuring the temperature ofthe gas flowing therethrough andthen inserting the inlet nozzle 12 and the pitot tube 15 into the effluent stream with the plug 59 in place to measure the velocity pressure. Appropriate calibration curves are used to convert. the reading on the Magnehelic gauge 20 into the gas velocity or the volume rate of flow through the stack.

With a blank piece of filter. paper in place and the plug removed 59, the blower 27 is started and a trial sample is taken at approximately isokinetic conditions to determine the average sample temperature through the filter and the orifice 24. Once the temperature on gauge 31 is determined, appropriate calibration curves can be used to calculate a reading on pressure gauge 25 to determine the necessary flow through the sampler for isokinetic conditions. The control valve 30 can thereafter be set with the blower 27 operating such that the reading on pressure gauge 25 is the calculated value.

Once the flow through the sampler has been matched to the velocity in the stack, the housing 14 is opened and a piece of filter paper 48 is placed up.- stream of the support screen 47 the catches 44 thereafter being fastened to secure the housing .14 therearound. Particulate samples are then drawn through the filter with the blower 27. operating and the control valve '30 'set such that the reading on the pressure, gauge 25 is maintained at the calculated value. The sampling period is set such that it is long enough to obtain a sufficient sample for accurate weight analysis. At 0.1 grains per standard cubic foot, 1 minute is an adequate sampling time. Afterthe particulate sample is obtained, a

- gas analysis is made with an Orsat analyzer, if required.

The filter material 48 is removed and a clean filterinserted for another sample. H

When field tests are completed, the filters are returned to a laboratory where they are brought to the same temperature and humidity conditions at which they were originally weighed. The sampler is rinsed with solvent and the washings evaporated at 200F. The

7 weight gain of the washings is divided on a time weighted basis among the filters taken. The weight gains of the filters are determined, corrected for'the blank filter weight changeand the material washed from the sampler, and then calculated on the basis of grains per cubic foot at standard conditions and total pounds per hour based on the emission velocity and area of the stack. i v

The sampler of the present invention is able to handle a greater volume of flow than was possible with heretofore existing units. As such, valid sampling is possible in shorter sampling periods. Consequently, numerous valid emission data points are obtainable which is advantageous in the case of a source changing emission.

The ability of the sampler to match the velocity in the stack, that is, to sample particulate emissions under isokinetic conditions, eliminates a variable in the testing procedure and permits a more accurate sample to be obtained. I

Use of the alternate nozzle '60 having a reduced intake area permits the sampler to match a flow four times that achievable using the standard nozzle; Such, obviously, increases the range of usefulness of the device.

Constructing the sampler entirely of aluminum achieves a light weight apparatus. Separating the suction blower 27 from the sampler, by means of the length of flexible hose 28, further lightens the assembly. Incorporating the pitot tube as an integral part of the apparatus permits simultaneous and continuous stack gas velocity measurements during sample collection. Such is also valuable in verifying the accuracy of the sampling procedure.

Positioning the butterfly valve 30 after the filter housing 14 eliminates particulate accumulations at the valve and simplifies necessary cleaning of the sampler after each test. Mounting the two pressure gauges 20 and 25 and the temperature gauge 31 on a single contion and a downstream housing section, said upstream and downstream housing sections being removably connected together at least at one edge thereof to facilitate rinsing of the sampler upstream of said downstream section, a screen support disposed between said upstream and said downstream sections, and a sheet of filter material supported on said screen support and removably disposed between said upstream and downstream sections;

a substantially unobstructed cylindrical tube disposed between said inlet nozzle and said filter means for conducting all said gas directly from said inlet nozzle to said filter means, whereby the entire flow of gas passing through said inlet nozzle impinges on said sheet of filter material;

suction pressure applying means disposed at the downstream end of said sampler for causing a flow of gas from said stack into said inlet nozzle-and through said sampler;

tubular means disposed between said filter means and said suction pressure applying means for conducting gas through said sampler responsive to suction pressure applied by said suction pressure applying means, said tubular means comprising a rigid tubular section attached to said filter means and a flexible tubular section disposed downstream of said rigid tubular section and attached to said suction pressure applying means, said flexible tubular section being of a length sufficient to' permit separation of said suction pressure applying means fromthe rest of said sampler, to lighten and facilitate use thereof;

a flow-measuring orifice disposed in said rigid tubular section;

. a control panel mounted on said rigid tubular section;

means mounted on said control panel and associated with said orifice for measuring the volume rate of gas passing through said sampler;

' means mounted on said control panel and associated with said pitot tube means for measuring the veloc ity of gas flowing through said stack; 7

temperature measuring means mounted on said control panel and adapted to measure the temperature of the gas passing through said rigid tubular section; and

control valve means disposed in said rigid tubular section downstream of said orifice for adjusting the volume rate of gas passing through saidsampler to make the same kinetically equivalent to said velocity of gas flowing through said stack.

2. A sampler as'in claim'l in which said control valve means comprises a shaft journaled in said rigid tubular section, a butterfly valve mounted on said shaft, means to rotate said valve with respect to said rigid tubular section and means to retain said valve in a desired position relative to said rigid tubular section.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US310157 *Dec 30, 1884 Filter
US1296922 *Jul 31, 1916Mar 11, 1919Adolfo De ClairmontCombined air and decarbonizing valve.
US1775127 *Sep 14, 1927Sep 9, 1930Willys Overland CoCarburetor choke control
US2074481 *Apr 28, 1934Mar 23, 1937Allan Macmullen EdwardScalp cleansing device
US2285829 *Jul 15, 1939Jun 9, 1942Maage Jr Alfred EDamper regulator
US2408661 *Nov 20, 1943Oct 1, 1946Designers For Industry IncAir-speed indicator
US2452224 *May 7, 1945Oct 26, 1948Collett Jr James DGas sampling apparatus
US2613454 *Jun 10, 1949Oct 14, 1952Hoover CoDemonstrating device for suction cleaners
US2722998 *Mar 29, 1952Nov 8, 1955Albert L ChaneyFilter apparatus
US2901626 *Apr 29, 1958Aug 25, 1959Huettenwerk Oberhausen AgApparatus for the analysis of hot, dust-laden gases
US2932966 *May 14, 1957Apr 19, 1960British Thomson Houston Co LtdApparatus for smoke detection
US2966169 *Jun 19, 1958Dec 27, 1960Clark B ReeceCombined insulation trim and damper positioning means for ducts
US3252323 *Dec 29, 1961May 24, 1966Litton Systems IncParticulate sampling device
US3395516 *Jan 31, 1964Aug 6, 1968Navy UsaAirborne aerosol collector
US3603155 *Feb 2, 1970Sep 7, 1971Chromalloy American CorpMethod and apparatus for mass emission sampling of motor vehicle exhaust gases
US3672225 *Aug 13, 1970Jun 27, 1972African Explosives & ChemGas sampling
FR1405386A * Title not available
GB927271A * Title not available
SU158137A1 * Title not available
Non-Patent Citations
1 *German Printed Applicat on No. 1,126,649, Printed 3-29-62, (1 sheet drawing, 2 pages specification).
2 *Solnick R. L., Sampling Particulate Matter, The Oil And Gas Journal, Oct. 15, 1956, Pages 120 124.
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3892549 *Jun 13, 1974Jul 1, 1975Combustion Equip AssGas dilution apparatus
US3903745 *Apr 22, 1974Sep 9, 1975Bolser Clark MGas sampler for collecting and measuring gaseous emissions from flues
US3965748 *Nov 18, 1974Jun 29, 1976Rader Companies, Inc.Apparatus for automatically measuring particulate emissions in gas flow
US3976457 *Aug 13, 1975Aug 24, 1976The United States Of America As Represented By The Administrator Of The United States Environmental Protection AgencyIn-stack filter cell
US4079622 *Sep 10, 1976Mar 21, 1978Snamprogetti S.P.A.Apparatus for determining the smoke density of flue gases of gas and fuel oil
US4140006 *Mar 9, 1978Feb 20, 1979Saphymo-StelDevice for taking samples of dust in a gas flow
US4269615 *Mar 10, 1977May 26, 1981American Hospital Supply CorporationFilter assembly
US4381681 *Dec 8, 1980May 3, 1983The United States Of America As Represented By The Administrator Of The Environmental Protection AgencyParticulate sample collector
US4382808 *Jun 26, 1981May 10, 1983Beckman Instruments, Inc.Assembly for holding a filter
US4442699 *Feb 23, 1981Apr 17, 1984Centre De Recherches Metallurgiques-Centrum Voor Research In De MetallurgieMonitoring the dust content of gaseous fluid
US4461184 *Jul 8, 1982Jul 24, 1984Her Majesty The Queen In Right Of Canada, As Represented By The Minister Of National DefenceCompressed breathing air sampling device
US4549887 *Jan 10, 1983Oct 29, 1985Joannou Constantinos JElectronic air filter
US4686848 *Nov 20, 1984Aug 18, 1987Umec CorporationHigh temperature particulate filter media test unit
US5090257 *May 9, 1990Feb 25, 1992The United States Of America As Represented By The Secretary Of The ArmyAutomatic isokinetic aerosol sampling system
US5264026 *Dec 3, 1992Nov 23, 1993Michaud, Coolev, Erickson & AssociatesCentralized laser plume evacuation system through articulating arms
US5332512 *Mar 31, 1993Jul 26, 1994Pacific Scientific CompanyIsokinetic diluter for particle measuring instrument
US5409511 *Nov 23, 1993Apr 25, 1995Michaud, Cooley, Erickson & Associates, Inc.Centralized laser plume evacuation system through articulating arms
US5511409 *Sep 19, 1994Apr 30, 1996Knaebel; Kent S.Measurement of emission levels in a gas stream
US5956946 *Mar 19, 1998Sep 28, 1999Yamada CorporationVehicle exhaust-gas purifier
US6016688 *Nov 12, 1998Jan 25, 2000Rupprecht & Patashnick Company, Inc.In-stack direct particulate mass measurement apparatus and method with pressure/flow compensation
US6021678 *May 27, 1998Feb 8, 2000Kennecott Utah Copper CorporationApparatus for transporting emissions from a stack
US6023981 *Jul 3, 1996Feb 15, 2000Phillips; Terrance D.Sampling box
US7141090 *Mar 28, 2003Nov 28, 2006Avl North America Inc.Active filter temperature control
US7387291 *May 16, 2005Jun 17, 2008Honeywell International Inc.Collapsible shaft and control assembly
US20040191130 *Mar 28, 2003Sep 30, 2004Gerald MarekActive filter temperature control
US20060255307 *May 16, 2005Nov 16, 2006Honeywell International, Inc.Collapsible shaft and control assembly
US20110232362 *Mar 23, 2010Sep 29, 2011Caterpillar Inc.Detection of exhaust filter effectiveness
US20130095744 *Oct 17, 2011Apr 18, 2013Lennox Industries Inc.Sensor mounting panel for an energy recovery ventilator unit
U.S. Classification73/863.3, 55/417, 55/493, 55/503, 96/413, 55/418, 55/501, 251/305, 73/863.25, 55/467, 73/28.4, 55/DIG.340, 96/422
International ClassificationG01N1/22, B01D46/42
Cooperative ClassificationY10S55/34, B01D46/442, B01D46/0012, G01N2001/2223, G01N2001/225, G01N1/2202
European ClassificationG01N1/22B, B01D46/44C, B01D46/00C40
Legal Events
Oct 31, 1980AS02Assignment of assignor's interest
Effective date: 19801014