Title: This Presentation is provided to you by: WeldCanada.com Industry Standard Welding Procedures Software CSA, AWS, ASME and API Welding Codes
1This Presentation is provided to you by
WeldCanada.comIndustry Standard Welding
Procedures Software CSA, AWS, ASME and API
Welding Codes
2Welding fume Management
3Welding fume Management
- In what units is fume generation measured?
- What units apply to particulate TLVs?
- A FCAW welder produces how much fumes per year?
4Fume emission level versus shielding atmosphere
Fumes (mg/min.)
1.000
Wire ER 70S3 dia. 1,2mm
280 - 300 A
800
740
28 - 30 V
600
470
400
350
290
190
200
150
0
100
20
10
5
0
CO2
O2
0
0
5
5
8
1,5
0
80
85
90
92
98,5
Ar
5Influence of CO2 content in the shielding gas on
CO emissions
CO content (ppm)
200
160
150
130
120
100
80
Ar 3,5 O2
50
40
0
0
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7- Airborne particulates
- Typical size range
Very fine (10E-8 cm) Fine (10E-4 cm)
Coarse (1 cm )
Atmospheric dust
Welding fume and dust
Tobacco smoke
Coal dust
Cement dust
Respirable particles
8Factors affecting fume generation rate
- Type of shielding gas if applicable to the
process - Welding current
- Welding voltage
- Arc length
- Polarity
- Current density
- Humidity
- Base plate
- Electrode angle
- Electrode type
- Formulation of the electrode and wire
9Fume emission testing device
- Filters weighed before and after test
- Welding time known
- 30 seconds/1 min exhaust
- fume emission rate calculated average of five
readings - measurements in mg/minute
- Rotating table
- FCAW gun mount
- AWS F 1.2-92( Laboratory method for measuring
fume generation rates - and total fume emission for Welding and Allied
Processes) - 20mm plate, 20 inch dia, 4 inch efffective, 120
lbs .
10- Typical fume generation Rates
Process
Range g/min
SMAW
0.2 - 1.2
FCAW
0.5 - 3.5
GMAW
0.1 - 0.5
GMAW(AL)
0.1 - 1.5
11The filter is about the size of a medium PIZZA!
- Clean and used filter, after 30 seconds!
12Welding fumes composition
13Welding fumes composition
14Potential Health Effects
15- Hexavalent chromium is a known lung carcinogen
- SMAW stainless steel electrodes produce high
level of Cr VI ( 50 - 70 of total chromium) - Lithium compounds reduce Cr VI significantly
- FCAW stainless steel electrodes produce high
level of Cr VI ( 30 - 60 of total Chromium) - GMAW of stainless steel produces very little
Cr VI ( lt 10 of total Chromium) - ANSI/AWS F3.1 - 89 Guide for Welding Fume
Control
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19?
fume generation g/min
Welding amperage
20 Influence of the shielding gas and parameter set
up on fume emission level in GMAW
(Wire ER 70S3)
Fumes (mg/min)
1.000
300 A
800
600
400
350 A
200
Tension (V)
0
15
20
25
30
35
40
Ar 10 CO2
Ar 18 CO2
Ar 3 CO2 1 O2
213-D representation of fume generation for non
pulsed GMAW
- For a given wire feed speed or amperage
- Low fume generation in short circuit range
- As voltage is increased, transfer transits
through globular range causing a first maxima - Fine tuning of spray transfer gives a minima
- As voltage increased beyond the optimum, fume
generation rate increases
22Fume concentration is measured in Milligrams per
cubic meter (mg/m3)
23Some terms used in the welding fume legislation
- OSHA Occupational Health and Safety
Administration - PEL Permissible Exposure Limit (8 hours)
- TWA Time weighted average (8 hour exposure)
- NIOSH National Institute of Occupational Safety
and Health - ACGIH American Conference of Governmental
Industrial Hygienists - OEL Occupational Exposure Limits (8 hours)
- TLV Thresh hold Limit Value (8 hours)
- TWAEV Time Weighted Average Exposure Value (8
hours) - STEL Short Term Exposure Limit ( TLV-STEL 15
minutes) - C Ceiling value ( TLV-C instanteneous max
value not to be exceeded) - General ventilation must move 2,000 cu feet per
minute - Each welder should have 10,000 cu feet of
barrier free work space - Serious violation 7,000 per violation
- Repeat violation 70,000 per violation
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25Air Sampling Meter
26- Daily variation of Fume Concentration
Actual Exposure
Fume concentration mg/m3
Exposure limit Time weighted Average
0800 1200
1600
27Fume generation ratesFCAW SMAW
28GMAW valuesTypical fume generation rates at 260
amps
29MCAW valuesTypical fume generation rates at 260
amps
30FCAW valuesTypical fume generation rates at 260
amps
31Fume weight per welder per year ?
- Fume generation rate of 1g/minute
- 2000 hours/yr at 20 duty cycle 400 hours
welding time - 400 hours X 1 g/minute X 60 24,000 grams 52.8
pounds - Equal to the weight of one coil of wire per year!
32FUME GENERATION 1.6 mm FCAW 200,000 HOURS OF
ARC TIME NOTE 200,000 hours of arc time at
18 duty cycle translates to approximately 556
welders.
33FUME GENERATION 1.6 mm FCAW 200,000 HOURS OF
ARC TIME NOTE 200,000 hours of arc time at
18 duty cycle translates to approximately 556
welders.
Through choice of gas and wire fumes
reduced Annually by 4.75 MT!!
34Influence of pulsed current on fume emission level
ER 70S3 1,2mm / ARCAL14
Fumes (mg/min)
800
Arcal 14
Arcal 14 pulsed
600
400
200
0
100
170
240
300
350
Amperage (A)
35FUME EMISSION LEVEL
Metal Cored Wire
Rutile FCW for all positions
Fume emission level (g/min)
Fume emission level (g/min)
1,2
1,2
1,05
1
1
0,8
0,8
0,57
0,6
0,6
0,52
0,37
0,4
0,4
0,2
0,2
0
0
GREEN 101
SD100
SD206
SD207
ARCAL 22
ARCAL 22
ATAL 5
ATAL 5
Parameter set up I 250 A U 26 V
36Source capture
37Applications?
38Source capture?
39Fume extracting gun
40Test results of air quality
41Welding Fume management