United States
Environmental Protection
Agency
Environmental Sciences Research EPA-600/2-79-115
Laboratory June 1 979
Research Triangle Park NC 27711
-
Research and Development
Evaluation of
Stationary Source
Particulate
Measurement
Methods
Volume III. Gas
Temperature Control
During Method 5
Sampling
-------
Thnne
1.
2.
3.
4.
5.
6.
1.
8.
9.
RESEARCH REPORTING SERIES
and a
'elated
Environmental Health Effects Research
Environmental Protection Technology
Ecological Research
Environmental Monitoring
Socioeconomic Environmental Studies
Scientific and Technical Assessment Reports (STAR)
Interagency Energy-Environment Research and Development
"Special" Reports
Miscellaneous Reports
b-rlen assi9ned to the ENVIRONMENTAL PROTECTION TECH-
nn S- ™lsseries Ascribes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
oZ'd^th de9radation from P°int and "on-point souTces of pollu°onP ?hfs lo?k
of nonft n W °r ',mpr°Ved technol°gy req^i^d for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
-------
EPA-600/2-79-115
June 1979
EVALUATION OF STATIONARY SOURCE PARTICULATE
EVALUAiiu
Volume III. Gas Temperature Control During
Method 5 Sampling
by
Edward T. Peters and Jeffrey W. Adams
Arthur D. Little, Inc.
Cambridge, Mass. 02140
Contract No. 68-02-0632
Project Officer
Kenneth T. Knapp . .
Emissions Measurement and Characterization Division
^Environmental Sciences Research Laboratory
Research Triangle Park, N.C. 27711
ENVIRONMENTAL SCIENCES RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U S ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK, N.C. 27711
-------
DISCLAIMER
and policies of the U S nv
ment10n of trade names or commercial
commendation for use Lomrnercial
the
Agency' nor does
constitute endorsement or re-
11
-------
ABSTRACT
controlling the P™f hertin, , element For ea f™.^ anj external
tack at airaneni an
controlng e P™ .
were measured in the stack, at airaneni an intervals.
positions «l"'?.tht1s"g11nShfJ"^ ££ Served to reach
SSraSSS! ^^fjeri.nts in which typi
l
. Measure-
erved to reach a state of
s in which typi.l stat.nary
i «
s:^r M jsi n ?e so fe ro:sruedH=tu
profiles along the sampling train. The results rru predicted
^-^^^
s^Wv^S'S^^.^*'1-^
Pa 1Stma" emerature is recorde
. ?Ms1procedufeSfotrmcrnatro"ing gas temperature is recorded
as a modification to Method 5.
ill
-------
TABLE OF CONTENTS
ABSTRACT """"
i v
LIST OF FIGURES
LIST OF TABLES V
vi
ACKNOWLEDGEMENTS
I. CONCLUSIONS ]
II. INTRODUCTION 2
III. EXPERIMENTAL PROCEDURES 4
IV. RESULTS AND DISCUSSION 7
-------
FIGURES
Number
Page
Train ' "' a ''lcl-"uu ° sampling
1 Schematic Presentation of a Method 5 Sampli
4
n
as a
I W
8 Temperature Gradients Across Sampling Train as a
Function of Time - Runs lla and lie 16
9 Schematic Presentation of Average Gas and External
Temperature Distribution Alona S 1 T •
a and lie 17
GmpGPcltLIK*6 Gr*3n 1 Pirf"^ Ar*v»nc c c^r«^i •; «* — T •
c j. • >"• **%* i^ii uo ni^i Uoo oarnpiino I P3in 3c a
18
12 19
11 Schematic Presentation of Average Gas and External
Temperature Distribution Along Sampling Train . R,
12 Temperature Gradients Across Sampling Train as a
Function of Time - Run 13 2Q
13 Schematic Presentation of Average Gas and External
Temperature Distribution Along SampHng Train _ ]
21
vx
-------
TABLES
Number
1 Plan and Objectives of Experimental Runs
Page
6
2 Summary of Run Conditions and Average
Temperatures after System Equilibration
vii
-------
ACKNOWLEDGEMENTS
35
viii
-------
I. CONCLUSIONS
Based upon the measurement of gas temperatures within a Method 5 sampling
train as influenced by variations in stack gas temperature samp ing rate,
filter box temperature and reference point temperature and location for
controlling the probe heating element, the following conclusions can be
drawn:
. External reference temperatures do not necessarily represent nor
permit control of internal gas temperatures. Gradients of up to
100°F can occur under certain conditions.
. Heating and/or cooling of the gases being sampled can occur or
can be accomplished over very short distances anywhere along
the collection system.
. A gas temperature of 250°F can be maintained at the filter even
though the gas is considerably hotter (or colder) at the back
of the probe. The thermal gradient across the filter support
glass frit is generally less than 10°F.
. Flow-rate variations of 0.5 to 1.2 cfm have only a moderate
influence on existing temperature profiles within the system.
Higher flow rates tend to smooth out the profile.
. Variations in gas stream moisture content influence the tem-
perature profiles within the train but should not prohibit
desired temperatures from being attained.
. The best technique for reliably maintaining desired gas tem-
peratures is by using a proportional controller to regulate
probe heating. The reference junction should be mounted in-
ternally at the back end of the probe.
-------
II. INTRODUCTION
a nozzle, glass-lined probe, h effla'
* -
a cone or plate element A small ™
uniform distribut on Sf heat w?Jnin ?he
static temperature control!
heated with
fdded to provide a
Systems emPloy the™°-
within the sampling system
T r
control of gas temperature
(1) Federal Register 36 No. 247, 24875-24895 (December 23, 1971,.
(2) Federal Register 39 No. 177, 32852-32874 (September 11, 1974).
-------
HEATED AREA FJUER HOtDER THERMOMETER CHECK
\ /
PROBE
REVERSE-TYPE
PITOT TUBE
\ VACUUM
\ GAUGE
MAIN VALVE
DRY TEST METER AIR-TIGHT
PUMP
VACUUM
LINE
IMPINGERS ICE BATH
8Y-PASS,VALVE
PITOT MANOMETER
ORIFICE
FIGURE 1 Schematic Presentation of a Method 5 Sampling Train
-------
HI. EXPERIMENTAL PROCEDURES
All measurements were -p u-- „ • ,
train (Research AppHae ^kSSiSiS f rticu]^e sampling
ppae ki ng
samples by the Method 5 procedure Prior ff 2J JP 5™Ve2 f°r Co11ecting
several small modifications were made to tMc 5 • U?16- descn'bed herein,
raw^%5£ £ r ? VF° =-d i.
'"*"1
— ' Position
2 In stack
3 Ambient
Midway along probe liner,
4 external
Midway along probe liner,
5 internal
6 ^ac,k of Probe liner, external
7 Back of probe liner, internal
8 Front of filter, external
9 Jront of filter, internal
10 °ack of filter, external
Back of filter, internal
leak-tight seal. The iunctionnf th/h * The epoxy Provided a
the position of intere t and ^ere cenLrederTn°C?hUpPleS "T 10Cated a
out with the onros hespHtran
-------
.
encountered in the field.
and the objective of individual runs is given in Table 1.
-------
IflBLh 1
PLAN AND OBJECTIVES OF EXPERIMENTAL RUNS
RUN NO.
1
2
3
4
5
10
11
12
13
Stack Gas
Hot
Hot
Hot
Hot
Hot
Cold
Cold
Cold
Cold
Hot
Hot
Hot
Hot
CONDITIONS
Filter Box Preset Temp.
250°F
250°F
225°F
225°F
250°F
250°F
250°F
250°F
250°F
250°F
250°F
250°F
Probe Heater Control
Preset
Manual adjustment
PC from #5 ~130°F
PC from #5 ~140°F
PC from #5 ~200°F
PC from #5 ~250°F
PC from #5 -250°F
PC from #5 ~200°F
PC from #10 ~250°F
PC from #10 ~250°F
PC from #5 -240°F
PC from #10 ~250°F
PC from #6 ~250°F
OBJECTIVE
To observe temperature distribution and gradient for
preset heater values.
To measure gradients when gas temperature at back of
probe (and in filter box) is maintained at 250°F.
To see how efficiently the filter can reheat the gas
after passage through a fairly cold probe.
Similar to Run 3, but lower filter box temperature.
Similar to Run 4, but higher probe temperature set to
achieve a gas temperature of 250°F at back of probe.
To see if probe heating is sufficient to bring a cold
nSh» 9^ •*emPe!"ature UP to 250»F at the exit from the
probe and to determine temperature gradients between
the gas and external system.
Similar to Run 6, but including higher sampling rates.
mnnrp ?h" 6> but "itn a c°1d stream saturated with
moisture. The proportional control temperature was
reduced to 200°F in an attempt to achieve a probe exit
gas temperature of 250°F.
To investigate the ability to control gas temperatures
' 1n
Similar to Run 9, but utilizing a hot gas stream.
To simulate gas temperatures for a coal-fired boiler
ofS robe6 heat6r reference functl"°n external at
reference point in
Similar to Run 11, but reference point in gas stream
at back of probe,,
-------
1 v r\ c. o u L. t *J r*1 *
^=£ SS3W^=K.HT5ffl~r
can be more easily demonstrated.
the train is shown schematically in Figures.
a
being about 10°F hotter than for the lower sampling rate.
box is maintained at 250°F.
-------
TABLE 2
CO
Run No.
2
3a
3b
4a
4b
4c
5a
5b
5c
6a
6b
6c
7a
7b
7c
8a
8b
8c
9a
9b
9c
lOa
lOb
lOc
lla
lib
He
12
13
Probe
Heater
(All
Filter Box Run
Numinal Control Temp "
Sampling Rate Control
(cfm)
0.5
0,5
0.5
1.25
0.5
0.8
1.25
0.5
0.8
1.25
0.5
0.8
1,25
0.5
1.25
1.6
O.b
o.a
1.25
1.25
0.8
0.5
1.25
0.8
0.5
0.5
0,8
1.25
0.5
0,5
Point*
_ — _
130
130
140
140
140
200
200
200
250
250
250
250
250
250
200
200
200
250
250
250
250
250
250
240
240
240
250
250
*•— —
#5
#5
#5
#5
#5
#5
#5
#5
#5
#5
#5
#5
#5
#5
jfi
#5
#5
#10
#10
#10
#10
#10
#10
#5
#5
#5
#10
#6
300
250
250
250
225
225
225
225
225
225
250
250
250
250
250
250
tou
250
250
250
250
250
250
250
250
250
250
250
250
250
Time
(min)
17
20
18
16
10
12
18
8
6
8
23
25
20
16
19
25
18
8
15
29
18
35
40
33
26
17
17
17
29
12
temperatures
......v-iui. ii.il. nxniunuj nriCK ilSltN tyUi LlBKflTlON
are given in degrees Fahrenheit.)
Measured Average Temperatures at
1
410
410
410
410
415
420
415
420
425
425
95
100
100
. 75
75
75
95
90
95
90
95
95
430
425
425
345
345
340
340
340
2
105
100
100
105
105
105
105
100
100
100
100
100
100
80
80
80
100
100
100
100
95
95
105
105
105
80
80
80
85
85
3
275
255
155
215
175
195
220
240
255
260
300
280
275
295
270
260
355
340
315
235
210
195
250
230
200
320
320
325
275
240
4
315
300
250
300
255
285
300
285
310
325
250
225
215
230
205
185
275
275
275
185
180
175
290
275
250
300
305
315
265
240
5
235
210
730
160
145
150
165
200
200
200
250
240
240
245
242
230
210
200
195
200
185
180
180
180
165
245
240
250
205
195
Indicated
6
280
245
140
195
160
175
200
235
240
245
320
310
305
310
285
270
325
315
305
250
230
215
230
225
195
330
330
340
280
Position
7
265
255
240
270
205
210
215
220
220
225
265
275
275
255
260
255
260
255
255
245
255
250
245
250
250
240
250
260
235
235
s* (Round
8
275
265
230
250
205
205
220
230
235
240
280
285
285
280
280
265
275
275
275
250
255
240
245
250
245
270
290
300
255
240
ed Off)
9
265
260
250
275
210
215
220
225
220
220
275
285
285
260
255
255
265
275
265
260
265
265
10
270
270
220
260
210
210
220
230
230
235
280
285
290
270
275
265
270
265
270
260
265
265
260
270
285
240
*A description of the various position-; tw mm
-------
300 -
Run 2
Stack Temperature:
Sampling Rate:
Probe Heater:
410 F
0.5 cfm
Manual Adjustment to T (Probe
Back Internal) =250°F
250°F
10
Time — Minutes
5 10
Time — Minutes
FIGURE 2 Temperature Gradients Across Sampling Train as a Function of Time - Run 2
-------
400
Run 2
Sampling Rate: 0.5 cfm
Probe Heater: Manual Adjustment to T (Probe Back
internal) = 250°F
Filter Box: 250°F
u_
o
Q.
E
QJ
350
300
(250)
Stack
X
1
1
Probe
1 4r— A
Filter Box
A
*
Distance Along Sampling Train
10
-------
400
Run 3
Probe Heater P.C.: No.5at130°F
Filter Box: 250°F
400
350
Run 4
Probe Heater P.C.: No.j5 at 140°F
Filter Box: 225 F
Distance Along Sampling Train
Distance Along Sampling Train
FIGURE 4 Schematic Presentation of Average Gas Temperature Distribution Along Sampling
FIGURE 4 Schematic^ ^^ of Sampl1ng Rate _ Runs 3 and 4
-------
probe at
(0 .5
at the
for
of the
The
at the back of the probe fnrth Sampln9 system. Th
influence of sampling rate for Runs CaSS as °ver 100°F-
would be exPectedP, rtfUnS
The
sampling from an ESP-
heater control at Posito s 5 lo and 6§ ™ ^Ce °f 25°°F probe
box temperature of 250°F Th expeHmfntl? F+ tlVJly? a"d a filter
evaluations is presented schema ticallv ?n I- ta obtained f<>^ these
probe temperature is cont^lled exteina lv *?T S ttlrough 13' When
a very large gradient is ob erve^ ^ acros the svst^^-Jh ^ Pr°be'
tures as high as 330°F at the bark nf IL system, with gas tempera-
front of the filter as shown in P- S probe and 270°F at the
however, indicate that the athPr ;, ExarPination of Figures 9
at this reference posltfo ?esuHs ?n very9 ?araP tp Stabilit^ encountered
probe and at the front of the filter Thi, K £mperatuj.e swings in the
temperature Tn other positions of the Jmnfinn * ^ sensmvlty to the gas
function position complete!? unaccepLb'e! ° "^ thl'S
to" vHvo!
performed in whithe gas tern JeraturP Tt^ C?r\d1t1ons- Run 13 was
250°F. The results are' res en ed Tn ure Tl^^nS'n^5 T^? &t
a very uniform temperature profile with M™ and 13. These data exhibit
between internal and external Dn^t?nnc '/ Ve7 sma11 Q^die
(where the gradient is 50°F) and , ?p f 9t the back of the
temperature'alongihe lengt^'of *°™ d1stHbution 1"
12
-------
300
CO
Probe-Midway
Run 7b o
Stack Temperature: 75 F
Sampling Velocity: 1.2 cfm
Probe Heater P.C.: No.5at250F
Filter Box: 250 F
5 10 15
Time — Minutes
5 10
Time - Minutes
FIGURE 5 Temperature Gradients Across Sampling Train as a Function of Time - Run 7b
-------
Q.
E
0)
Run 7a
Stack Temperature: 75°F
Sampling Velocity: 0.5 cfm
Probe Heater P.C.: No. 5 at 250° F
Filter Box: 250°F
Distance Along Sampling Train
Run 8a
Stack Temperature: 95°F
Sampling Velocity: 0.5 cfm
Probe Heater P.C.: No. 5 at 250°F
Filter Box: 250°F
(R.H. = 100% at 95°F)
Distance Along Sampling Train
Train -
**
and 8a
Distribution Along
-------
350
300
(250)
o 200
I
„
0.5 cfm
Run 8
Stack Tern peratu re: 95° F
Probe Heater P.C.: No. 5
Filter Box: 250°F
(RH = 100%at95°F)
Probe
Filter Box
Distance Along Sampling Train
Distance Along Sampling Train
FIGURE 7 Schematic Presentation of Average Gas Temperature Distribution Along
Sampling Train as a Function of Sampling Rate - Runs 7 and 8
-------
a.
340
320 —
300
Probe-Midway
Probe-Back
340
Filter-Front
5 10 15
Time — Minutes
5 10 15
Time — Minutes
340
Filter-Back
Run 1la
Stack Temperature: 345 F
Sampling Velocity: 0.5 cfm
Probe Heater P.C.: No. 5 at 240°F
Filter Box: 250°F
10
15
20
Runllc
Stack Temperature: 340°F
Sampling Velocity: 1.2 cfm
Probe Heater P.C.: No. 5 at 250°F
Filter Box: 250°F
-(280)
5 10 15
Time — Minutes
20
_L
5 10 15
Time - Minutes
20
FIGURE 8 Temperature Gradients Across Sailing Train as a Function of Time - Runs Ha and He
-------
400
350
300
£ (250)
•H>
CO
I
E
£
H 200
150
Run 11a
Sampling Velocity: 0.5 cfm
Probe Heater P.C.: No. 5 at 250°F
Filter Box: 250°F
Stack \j
• J
Probe
Filter Box
400
350
300
(250)-
200
150
Run 11c
Sampling Velocity: 1.2 cfm
Probe Heater P.C.: No. 5 at 250° F
Filter Box: 250°F
Stack
Probe
Filter Box
Distance Along Sampling Train
Distance Along Sampling Train
FIGURE 9 Schematic Presentation of Average Gas and External Temperature
Distribution Along Sampling Train - Runs lla and lie
-------
oo
340
320
300
o 280
260
0)
E (250
CD
240
220
200
Probe-Midway
5 10 15
Time — Minutes
20
200 -
340
320
300
280
260
(250)
240
220
200
Run 12
Stack Temperature: 345°F
Sampling Velocity: 0.5 cfm
Probe Heater P.C.: No, 10 at
250° F
Filter Box: 250°F
Filter-Front
J_
Time — Minutes
5 10 15
Time - Minutes
20
FIGURE 10 Temperature Gradients Across Sampling Train as a Function of Time -
-------
400
350
300
I
1 (250)
Q.
E
0>
200
150
Run 12
Stack Temperature: 345°F
Sampling Velocity: 0.5 cfm
Probe Heater P.C.: No. 10 at 250°
Filter Box: 250°F
Stack
Probe
Filter Box
Distance Along Sampling Train
FIGURE 11
Schematic Presentation of Average Gas and External
Temperature Distribution Along Sampling Train - Run 12
19
-------
ro
o
Probe-Midway
Run 13
Stack Temperature:
Sampling Velocity:
Probe Heater P.C.:
Filter Box:
340" F
0.5 cfm
No. 6 at 250° F
250° F
10 15
Time - Minutes
10 15
Time — Minutes
FIGURE 12 Temperature Gradients Across Sampling Train as a Function of Time - Run 13
-------
350
LL
O
I
£
3
CD
Q.
0)
300
(250)
200
150
Run 13
Stack Temperature:
Sampling Velocity:
Probe Heater P.C.:
Filter Box:
340° F
0.5 cfm
No. 6 at 250°F
250° F
Stack
Probe
Filter Box
r— ^
S
<
A A
•— • — i
_ — • i
A
Distance Along Sampling Train
FIGURE 13 Schematic Presentation of Average Gas and External
Temperature Distribution Along Sampling Train - Run
13
21
-------
For the range of experimental conditions considered in the set of runs
summarized in Table 2, including variations in stack temperature, sampling
rate and reference position for controlling the probe heater, it is
evident that large thermal gradients, appreciable temperature swings
with time and unpredictable gas temperature distributions along the
train are encountered in all cases where the probe heater is controlled
on the basis of an external reference temperature or gas temperature
behind the filter. However, it has been demonstrated that very good
control of gas temperature can be achieved by proportional control of
the probe heater element from an internal reference point at the back
of the probe. To minimize loss of particulate by collection on the
internal thermocouple and incomplete recovery during the train cleanup,
it is recommended that the reference thermocouple be enclosed in a
1/16 inch stainless steel sheath that is epoxied in place at the point
of entry into the sampling system. Only a slight modification to the
glass elbow joining the probe to the filter holder is required. In
this way, a gas temperature of 250°F at the exit of the probe as
called for by Method 5 can be maintained accurately and reliably.
22
-------
. REPORT NO.
EPA-600/2-79-115
TECHNICAL REPORT DATA
(Please read Instructions on the tererse before completing)
2.
!3. RECIPIENT'S ACCESSION NO.
TITLE AND SUBTITLE EVALUATION OF STATIONARY~SOURCE~ PARTI^~
CULATE MEASUREMENT METHODS
Volume III. Gas Temperature Control During Method 5
Sampling
5. REPORT DATE
June 1979
7. AUTHOR(S)
Edward T. Peters and Jeffrey W. Adams
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NO.
I
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Arthur D. Little, Inc.
Acorn Park
:ambridge, Massachusetts 02140
12. SPONSORING AGENCY NAME AND ADDRESS
Environmental Sciences Research Laboratory - RTP, NC
)ffice of Research and Development
J.S. Environmental Protection Agency
Research Triangle Park. N.C. 27711
15. SUPPLEMENTARY NOTES
10. PROGRAM ELEMENT NO.
1AD712 BA-18 (FY-76)
11. CONTRACT/GRANT NO.
68-02-0632
13. TYPE OF REPORT AND PERIOD COVERED
Interim 10/73 - 2/77
14, SPONSORING AGENCY CODE
EPA/600/09
Volume I was issued as EPA 650/2-75-051a, June 1975.
Volume II was issued as EPA 600/2-77-026, February 1977
A study was conducted to measure changes in gas temperature along the length of a
Method 5 sampling train due to variations in stack gas temperature, sampling rate filte
box temperature, and method for controlling the probe heating element. For each run
condition, temperatures were measured in the stack, at ambient and at four internal and
external positions along the sampling train at one minute intervals. Measurements
A/ere continued until the system was observed to reach a state of thermal equilibrium.
cor several experiments in which typical stationary source conditions were tested,
.ubstantial differences between gas temperature and external temperature were observed.
'he method employed for controlling the probe heater and the gas sampling rate were
hown to have major influences on gas temperatures and temperature profiles along the
amp!ing train. The results from these experiments demonstrate that gas temperatures
annot be predicted or controlled on the basis of externally measured temperatures.
he use of an internal thermocouple, having its reference junction at the back of the
robe, to proportionally control the probe heater element is shown to provide a predict-
ble gas temperature and a flat thermal profile along the sampling train. This pro-
edure for controlling gas temperature is recommended as a modification to Method 5.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
* Air pollution
* Particles
Flue gases
Collecting methods
Evaluation
* Temperature control
Revisions
13B
21B
14B
RELEASE TO PUBLIC
19. SECURITY CLASS (This Report}'
INCLASSIFTED.
21. NO. OF PAGES
31
20. SECUR!f7'CLASS (Thispage)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDI TION i s OBSOLETE
"23
------- |