Document r2kgxN3eBeJvjpx3Kjnv4b7a
The Ringelmann Chart--widely used, and abused, basis for municipal air-pollution control ordinal
N. >S
GUILTY OR NOT?
106
Municipal smoke inspectors are finding this an increasingly lough quellion to answer when it comes to proving, to ihe satisfaction o( ihe courts, theii cases against violators of anti-smoke ordinances. A key to the problem seems
to be the Ringelmatin Chart, a 70-yearold yardstick for amoke measurement published by the United States Bureau of Mines. Below we have two incidents in which courts have dismissed 'anti smoke charges for leek of evidence based on the proper use of the Ringel-
mann Chart. In a recent Chicago case, the Mu
nicipal Court convicted on industrial company of having violated the city's anti-smoke ordinance- This conviction was based on the testimony of a city smoke inspector who stated that, on two occasions, there was an emission of smoke of greater density than permitted under local ordinances based on the Jlingelmenn Chart.
The Appellate Court of Illinois set this decision aside on the ground that the following facts discredited the in spector's testimony: (1) defendant com pany had installed an electronic smoke indicator in the stack in question, and an experienced engineer had proved the device to be accurate, (2) the indicator recorded the density of the smoke on graphs on the days in question and these graphs did not show.emissions of den sity greater than permitted by ordinance specifications. . The inspector testified that he de
termined the smoke to be excessively dense by referring to the Chari, but he did rot state how long ho'd been on inspector nor his experience in that line. Nor did he state whether he'd fol lowed the standard Chart instructions.
The Appellola Court concluded: "The i
smoke abatement ordinance is necessary "
In a community like Chicago, and its i
enforcement is important. When, how- '
ever, the defendant in good faith ea.
ploys the most scientific means recast-
mended by Ihe city for detecting density
of smoke to ovoid violation of the ordi nance, and (he graphs do not show toy
record of No. 3 density for (he days is *
question, ft cannot then be said that
plaintiff sustained the burden of proviog'
defendant's guilt by the testimony of
the one smoke inspector as to the )-.
leged violation."
_]
St Louis inspectors, too, are havlog 1
their troubles in trying to pin down violators of city smoke ordinances. Re
cent charges brought against a local laundry were dismissed by a police. 1
judge. In this ease, three inspectors;*^
gathered evidence by observing the do . fendam's stacks from May through July.
Despite these efforts, the ease was .
thrown out of court on grounds thit the ;
Ringelmann Chart had not been used la ,
gathering evidence. And ao the dilemmo continues. Io
spite of its admitted inodequaciea, the .
Ringelmann Chert is used to defies -
smoke-density limits In many ordinsoees
because it is the only relatively simple
measuring method. Quite properly io
such cases, the courts refuse eontictloes
unless the Chart is used and used cor- rectly. But because of tho inconvenience -
of viewing the Chari at 50 feel, Inipe* tors often neglect to use It--or doo*
follow instructions to the letter. Power feels there ore ways out of thi*
dilemma. Watch future issues for * <
review of specifications definlni tho
Ringelmann Chart and suggestions for
making its principles easier to apply*
eNOINCUINO AND MANAGEMENT SECTION
yown
125 tOO T9
50 25
Process pressure, pitq
Condensate Velocity Fixes Pipe Size
^ To avoio too great a pressure drop In trap discharge lines Orrying a mixture of condensate and flash steam, the pipe Dost be large enough to keep velocity low. It U customary to allow maximum velocities of 1000 fpm per inch of inside Pipe diameter for dry iteam. To minimise erosion with flesh Beam carrying a high proportion of water, the velocity should be lower than this. The above chart may bo used for process pressures ranging from 25 to 150 psig, discharg ing to an exhaust pressure of 0 psig through o Schedule-40
./pipe. Example: A process kettle discharges 6470 lb per hr of
condensate at 75 psig through a trap to on 6-psig exhaust
line. What will tho velocity be? Find the flow of 6470 lb
per hr on tho lower left scale and fellow trace vertically to
intersect with the 2-ln,-pipe curve. Follow trace to right to
read velocity of 7400 fpm on the 75-psig aeale. This indicates
that pipeline is too small since velocity should be lesa than
2 X 1000 or 2000 fpm. Three-inch line gives velocity of 3300
fpm. .Still too high. So uao 3%-in. pipe. If larger pipe site
can't be used, a pump or condensate cooler must be installed
to maintain dlschargfrline oapachy, or flow will be reduced.
Succcmo or KM Holaday
Ifebiter Crovei, Mo.
i O POWER
ttCEMtER 1953
ENOINEERINO AND MANAGEMENT SECTION