Weld Fume Control Systems Overview. April 19, 2016 Steven Hill

Transcription

1 Weld Fume Control Systems Overview April 19, 2016 Steven Hill

2 Agenda Types of Welding Why fume extraction Where does welding fume come from Methods of control Substitution Souce Extraction Isolation Central Systems General Ventilation Personal Protective Equipment Safe Work Practices Questions

3 Types of Welding

4 Types of Welding - SAW (Submerged Arc Welding) - GTAW (Gas Tungsten Arc Welding) - GMAW (Gas Metal Arc Welding) - FCAW (Flux Cored Arc Welding) - Self Shielded - Gas Shielded - SMAW (Shielded Metal Arc Welding) - Other (Laser, Friction Stir, Autogenous )

5 Types of Welding - SAW (Submerged Arc Welding) Sub-Arc

6 Types of Welding - GTAW (Gas Tungsten Arc Welding) TIG (Tungsten Inert Gas)

7 Types of Welding - GMAW (Gas Metal Arc Welding) MIG (Metal Inert Gas) / MAG (Metal Active Gas)

8 Types of Welding - FCAW (Flux Cored Arc Welding) Innershield / Outershield

9 Types of Welding - SMAW (Shielded Metal Arc Welding) AKA Stick

10 Why Fume Extraction?

11 Why fume extraction? Enhance Employer-Employee Relations Provide a Cleaner More Professional Work Environment Improve the Business Image in Marketplace Meet AWS and OSHA Guidelines & Regulations Reduce Energy Costs

12 Where does welding fume come from?

13 Welding Fume Where Does It Come From? Welding fume potentially comes from three places: 1. Welding consumables (90-95% of fume) 2. Base metals 3. Coatings present on base material

14 Welding Fume exposure is determined by numerous factors: 1. Base metal being welded 2. Process, procedure and electrodes used 3. Coatings on the metal being welded 4. Number of welding arcs and volume of work area 5. Quantity and amount of ventilation 6. Position of the welders head with respect to the fume plume 7. Presence of contaminants in the atmosphere (adapted from Ashby 55) Welding Fume

15 Methods of Control

16 No one solution will fit all applications! Source Extraction Local Extraction General Extraction & Circulation Safe Work Practice Controls Substitution of Process/consumable Personal Protection Equipment

17 Substitution Welding Processes and Consumables

18 Substitution Welding Processes and Consumables Is it feasible and practical to substitute a welding process, consumable, gas, procedure or equipment technology that generates less fume?

19 Welding Fume Under the Microscope What is it? Percent fume produced by different welding processes (as % of pounds of consumable used) Submerged Arc (SAW) % MIG Wire (GMAW) % Cored Wire (FCAW-GS) % Stick (SMAW) % Cored Wire (FCAW-SS) % Estimates indicate SMAW and GMAW on mild steel, stainless steel, and aluminum are performed by 70% of welders

20 Substitution (Manual Electrodes) Fume Generation Rates and Elemental Fume Chemistry (Mild Steel) Product Dia. Voltage Current Melt - Off Rate Fume Gen. Rate Percent Polarity Classification (in) (amps) (lbs / hr) (g / min) Particulate Fleetweld 5P 5/ DC E DC DC Excalibur 5/ AC E AC DC DC Elemental Fume Chemistry ( % ) Fe Mn Si Na K F Al Ca Fleetweld 5P 5/ < Excalibur / <

21 Substitution Welding Procedure & Gas Selection GMAW (MIG welding) Fume generation per shielding gas (g/min, ER70S-3) Impact of gas selection, welding procedures & transfer mode Current (amps) Ar-5CO2-2O2 Ar-12CO2-2O2 Ar-20CO2-2O2 CO2 Gas Selection

22 Substitution Waveform Control Technology Unmatched control and customization leads to the development of lower fume generating weld processes STT Surface Tension Transfer Controlled heat input, spatter, and fumes Power Mode Improved arc stability at low settings Results are low heat input, virtually no spatter, and minimal fume generation Rapid Arc High travel speeds with low spatter and relatively low fume generation at elevated parameter conditions

23 Substitution Waveform Control Technology STT Major Achievements Reduced spatter with 100% CO 2 shielding gas Developed capability to use larger diameter electrodes Ability to control welding current independent of wire feed speed Reduced fume Measurements per ANSI/AWS F STT PROCESS: FUME REDUCTION ANALYSIS Electrode & Gas Combination Fume % Std. CV Short Arc STT E70S-3 & 100% CO2 1.49% 0.68% LHS & 90% He, 7.5% Ar, 2.5% CO2 0.57% 0.26%

24 Extraction Options Source Local General

25 Ventilation Overview No one solution will fit all applications! Local Extraction Source Extraction General Extraction & Circulation

26 Ventilation OSHA (c)(3)(i) Hoods. Freely movable hoods intended to be placed by the welder as near as practicable to the work being welded and provided with a rate of air-flow sufficient to maintain a velocity in the direction of the hood of 100 linear feet (30 m) per minute in the zone of welding when the hood is at its most remote distance from the point of welding. Local Ventilation Systems for Welding and Cutting Processes System Type Typical Airflow Comments Welding gun with cfm Extracts fume at the weld zone integral fume extraction ( m 3 /h) through GMAW and FCAW guns High vacuum source capture nozzle Flexible fume extraction arm Cross-draft welding table (slotted hood) Fixed exhaust hood Push-pull hood over welding robot cfm ( m 3 /h) cfm ( m 3 /h) cfm per ft 2 ( m 3 /h per m 2 ) cfm ( m 3 /h) Varies with hood height and space Captures fume through highvelocity, low-volume extraction nozzles; usually positioned by the welder Draws higher air volume and is easily positioned and repositioned by welder Excellent for controlling fume in a fixed location serving small part welding Used for overhead capture in fixed locations An engineered design to reduce exhaust air volume in a large, fixed welding zone Canopy hood Varies with hood design Uses larger air volumes to control an area where source capture is impractical Downdraft cutting table 150 cfm per ft 2 (2700 m 3 /h per m 2 ) Used in large, fixed, flat plane operations AWS F3.2M/F3:2:2001 Ventilation Guide for Weld Fume approved by American National Standards Institute June 15, 2001

27 Source Extraction

28 Source Extraction Low Vacuum (High Volume) HIGH volume of air extracted CFM Operates 6-12 from weld source Flexible Extraction Arms High Vacuum (Low Volume) LOW volume of air extracted CFM Operates 2-4 from weld source Fume Guns & Extraction Nozzles Small, Compact & Flexible Systems

29 Source Extraction Low Vacuum (High Volume) Extracts fume at source Mobile or stationary Disposable or self-cleaning filters User-friendly flexible arms Energy & Noise level considerations Other: Fixed downdraft and crossdraft tables

30 Source Extraction Low Vacuum (High Volume)

31 Source Extraction Mobiflex 100-NF, 200-M & 400 MS Mobile Systems Statiflex 100-NF, 200-M & 400-MS Wall Mounted System Low Vacuum Solutions Downflex 100-NF, 200-M & 400 MS Downdraft Tables Central Systems Statiflex 6000-MS Statiflex MDBs

32 Low Vacuum Source Extraction Arms

33

34 Source Extraction High Vacuum (Low Volume) Extracts fume at source Mobile or stationary Disposable, self-cleaning User-friendly nozzle or fume gun designs Energy & Noise level considerations Shielding gas consideration

35 Source Extraction Hi Vacuum - Fume Extraction Gun (off/on) Administrative Safe Work Practices Periodic inspection and maintenance of engineering control equipment is an important safe work practice control.

36 Source Extraction High Vacuum Solutions X-Tractor 1GC Miniflex X-Tractor 26, 36, &52 X-Tractor 3A, 5A, & 8A

37 Isolation

38 Isolation Separate, Automate & Ventilate Is it feasible and practical to: Switch from manual to automatic welding equipment and isolate the source of the fume Isolation - enclosing the source of exposure, or placing a barrier between employees and the source of exposure Risk of Creating a Confined Space... Precautions Necessary!

39 Isolation Controlled, contained local weld area or area within facility Hoods with curtains or enclosures which extract residual fumes Source extraction or PPE should be used if individuals are working within local, contained area

40 Robotic Fume Extraction Systems Multiple systems can be tied to a single filtration system MERV 11 & 16 rated filters Pressure differential switch for regulation of fan speed/air flow as the static pressure of the system changes Automatic On/Off controls Quick connect or spiral duct work Direct mounting fan to the Statiflex Filter Bank Isolation

41 General Extraction Push Pull/Circulator Systems Engineered solutions for improved indoor air quality Ideal applications: Source capture is difficult Large weldments with multiple welds In conjunction with PPE Benefits of a properly designed General Filtration System Precision controlled fans Performance with Variable frequency drive and pressure sensor technology ensures effective operation Save Up to 50% of operating electricity usage Real time performance adjustment Maintains peak performance Utility costs are lowered Conditioned air remains in the space Low maintenance Filters automatically clean at pre-set pressure differentials» Visual alarm when filters need changed

42 General Extraction: Push Pull Push Pull Advantages System can operate in Auto-mode Shifts can be set according to work schedule Units can be placed indoors/outdoors Can be integrated with the Flame Guardian System Units can be located outside of the area of coverage and ducted to extraction area Systems can be operated in areas with overhead obstructions Overhead cranes Jib cranes HVAC duct/plumbing Overhead conveyers Units can be placed on mezzanines Equipment self cleans the filters automatically at pre-set pressure differentials

43 General Extraction: Push Pull Principle: To move, extract and dilute welding smoke, motion must be created by pushing and/or pulling welding fume blanket Technique will depend on facility layout and design Note: Source extraction or PPE such as respirator should also be used

44 General Extraction: Push Pull

45 General Extraction: Circulators Circulator Advantages System can operate in Auto-mode Shifts can be set according to work schedule Can be installed by the owner System can be implemented in phases Allows for coverage in target areas units can be added when the budget allows Systems can be operated in areas with overhead obstructions Overhead cranes Jib cranes HVAC duct/plumbing Overhead conveyers Location Flexibility: Can be easily moved and added to as shop evolves Equipment self cleans the filters automatically at pre-set pressure differentials Quiet and Effective

46 General Extraction: Circulators

47 Welding Fume Extraction Systems Welding Fume Extraction systems require on-going Maintenance! Employers responsibility to monitor use of Engineering Controls! Employee training is a must and should be ongoing and repetitive!

48 Safe Work Practices

49 Safe Work Practices Operator Technique

50 Please note the following: The operation of welding fume control equipment is affected by various factors including proper use and positioning of the equipment, maintenance of the equipment and the specific welding procedure and application involved. Worker exposure level should be checked upon installation and periodically thereafter to be certain it is within applicable OSHA PEL and ACGIH TLV limits.

51 Personal Protection Equipment

52 Personal Protection Equipment Masks & Respirators OSHA only permits the use respirators to control exposure if engineering controls and safe work practice controls have been implemented and are inadequate. Use of respirators is allowed when potential exposure is 30 days or less Air Purifying Respirator Disposable half masks Filters fumes from breathing air Supplied Air Respirators Atmosphere-supplying, which provide clean, breathable air from uncontaminated source See OSHA 3079 (2002 revised)

53 Welding Safety Resources

54 Education/Training/Awareness Resources Welding Safety Resources Weld Fume Control Training Resources Regulation Awareness & Education Resources

55 Welding Safety Resource Lincoln Electric Safety Page

56 Welding Safety Reference Documents Everyone working in the welding industry is welcome to download a copy of: Lincoln Electric s E205 document, Arc Welding Safety free of charge Also available in Spanish Lincoln Electric has also created and provides free copies of the Welding Safety Interactive DVD

57 Lincoln Electric Weld Fume Control For More Information, contact: The Lincoln Electric Company Saint Clair Avenue Cleveland, Ohio USA

58 Users and employers have the sole responsibility for and control over workplace conditions, including the manner in which work is performed and the safety measures taken. Always read and follow applicable OSHA regulations as well as all information on product labeling and material safety datasheets (MSDS available at ) when using Lincoln Electric products. The operation of welding fume control equipment is affected by various factors including proper use and positioning of such equipment, maintenance of the equipment and the specific welding procedure and application involved. Users and employers should have an industrial hygienist check worker exposure levels to be certain that they are within applicable OSHA PEL and ACGIH TLV limits. Lincoln Electric does not warrant or assume any liability with respect to this information or advice. Moreover, the provision of such information or advice does not create, expand or alter any warranty on our products. Any express or implied warranty that might arise from the information or advice, including any implied warranty of merchantability or any warranty of fitness for any customers particular purpose is specifically disclaimed. This information is accurate to the best of our knowledge on the date provided.