In many occupations such as welding, workers are exposed to a combination of several hazards. One of these is the exposure to fumes, particularly those produced from welding processes involving electrical arcs. The inhalation of welding fume can cause both temporary side effects and longer term health complications. These health effects lower the productivity and quality of life of the welder which in turn costs the employer through reduced worker productivity and potential compensation. Current techniques of fume measurement determine bulk quantity of formation without regard to fume plume dissipation into the work place. While some research has been conducted into dissipation, measurements near the welding arc have proven difficult and either numerical or salt water modelling have been used. Such modelling aims to replicate the welding process but is ultimately detached from the actual welding variables involved and does not provide data on fume concentration. Since welder exposure is determined by both fume concentration and dissipation into the workplace measurement techniques which could provide both would be considered highly desirable. In the field of combustion research a number of different laser techniques are used to image soot particulates in flames. These techniques include laser scattering, laser extinction and laser induced incandescence. As yet none of these techniques have found application to the measurement or imaging of particulate matter in arc welding fume plumes. In the work presented here these techniques have been investigated for welding fume measurements of concentration and dissipation. Laser scattering was used successfully to image the fume plume close to the welding arc of actual gas metal and flux cored arc welding processes. The resulting images provided relative fume concentration maps that were quantified when combined with measurements from laser extinction. Laser induced incandescence, while successfully applied to the imaging of soot concentration in flames, was found to have limited capabilities when applied to welding fume particulates. Fume box measurements were undertaken for GMAW and FCAW to determine actual FFR in response to changes in welding variables. The results were in general agreement with those obtained from laser techniques and referenced in literature. The fume plume images collected from in-situ laser measurements were compared with those from previous modelling of plume shape, radial spread and virtual origin. Laser diagnostics demonstrated a number of capabilities not available with traditional fume measurements. The findings of this research provide unique insight into fume dissipation. Such findings can be applied to minimise the quantity of fume, the transmission to the breathing zone and ultimately worker exposure in the workplace. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1339888 / Thesis (Ph.D.) - University of Adelaide, School of Mechanical Engineering, 2008

No description available.

Welding is a widely used method to join two pieces of stainless steel. Since it produces a large amount of fume during the process, it can cause adverse health effects. The welding fume particles contain many elements. Among them Cr, Mn and Ni are of concern. These three elements can cause diseases if inhaled by humans, especially Cr(VI). In this project, welding fume particles are collected during welding of different stainless steel grades (austenitic AISI 304L and duplex LDX2101). Furthermore, different welding types (manual metal arc welding and metal active gas welding), shielding gas (MISON 2, MISON 18 and CORGON 18) and welding electrodes were varied (solid and flux cored wire). The particles were tested by scanning electron microscopy, energy dispersive X-ray spectroscopy, cyclic voltammetry and atomic absorption spectroscopy. The composition of the particles was measured and the surface chemical speciation estimated. In addition, metal release (Fe, Cr, Mn, and Ni) in phosphate buffered saline solution (pH 7.4, 37℃, 24h) from the particles was tested. Fe, Cr and Mn were found on the surface of the particles and released to different extent in the phosphate buffered saline solution (dominated by Cr).

Welding is a common industrial practice that has the potential to emit air pollutants. Emission factors are useful indicators to help in the understanding of the extent of pollution from a process and managing them to reduce or minimize health impacts. The objective of this thesis is to determine emission factors applicable to the gas metal arc welding (GMAW), under varying current and voltage conditions. The most used base metals and an electrode for the shipbuilding industry were considered. A weld fume chamber was used to achieve the project goals along with standard sampling and analytical procedures. Three test runs were performed for each sampling scenario to ensure repeatability. The EPA EF average for MS experiments with the ER70S-6 electrode is 5.2 g/kg, and for SS experiments with the ER316L-Si electrode is 3.2 g/kg, while the average results for this study were 6.81 g/kg and 3.28 g/kg respectively.

No description available.

Examensarbetet har utförts vid ABB Power Transformers i Ludvika i plåtverkstaden, där stora transformatorlådor svetsas ihop. Tillsammans med vår handledare på företaget utformades ämnet för examensarbetet att bedöma luftkvalitet och arbetsmiljö vid punktsvetsning i koppar. Det fanns misstanke om att exponeringen för koppar var hög och en utvärdering av luftkvaliteten behövde därmed göras. Ingen tidigare exponeringsmätning vid svetsning i koppar har genomförts i plåtverkstaden.   Syftet med examensarbetet var att utvärdera och komma fram till tre åtgärdsförslag för att skapa en bättre arbetsmiljö vid punktsvetsning samt att begränsa exponeringen av svetsrök som bildas vid svetsning i koppar. Tre åtgärder var företagets önskemål. En exponeringsmätning av luftföroreningar vid svetsning i koppar gjordes för att kontrollera halten av ämnen i svetsröken, i förhållande till de hygieniska nivågränsvärdena. Exponeringsmätningen gjordes personburet. Dessutom gjordes stationär mätning samt mätning med direktvisande instrument. Användning av skyddsutrustning och ventilationen granskades. I samband med exponeringsmätning genomfördes intervjuer.   Resultatet av exponeringsmätningarna har visat att det hygieniska nivågränsvärdet för koppar överstegs kraftigt vid punktsvetsning med MIGsvetsmetoden. Nivågränsvärdet för koppar är 0,2 mg/m3 och det högsta uppmätta värdet uppgick till 1,05 mg/m3, mätt utanför svetsvisiret. Utifrån observationer om användning av skyddsutrustning har det noterats att det finns tillgång till lämplig skyddsutrustning men att den inte används i den utsträckning som den borde. De tre åtgärdsförslag vi utvecklade är att; (1) införa rutiner för filterbyte med jämna mellanrum, (2) börja använda integrerade utsug i större utsträckning samt att (3) förbättra lokalens ventilation genom att installera deplacerande ventilation. De två beräknade åtgärdskostnaderna, åtgärd (1) och (2), följer företagets PayOff-princip på 3 år.   Examensarbetet ska bidra till att alla medarbetare i plåtverkstaden blir medvetna om de risker som exponering av svetsrök innebär, men även att de tänker på sin egen och andras säkerhet och hälsa i deras dagliga arbete samt vidtar åtgärder som effektivt minskar exponeringen av svetsrök. Att satsa på en bra arbetsmiljö innebär kostnader för exempelvis inköp av skyddsutrustning och utbildning om risker. Detta bör dock inte ses som en kostnad utan att det snarare är en investering på sikt, som förbättrar medarbetares hälsa och prestationsförmåga i arbetet. Avslutningsvis: Att satsa på en bra fysisk och psykosocial arbetsmiljö är en investering för att få ett väl fungerande och lönsamt företag! / This thesis has been carried out at ABB Power Transformers in Ludvika at the plate shop, where large transformer boxes are welded together. The topic of the thesis was formulated together with our supervisor at the company, to assess air quality and work environment at the spot welding of copper. Copper exposure was suspected to be high, and an evaluation of air quality was needed. No previous exposure measurements when welding in copper have been made in the plate shop.   The purpose of this study was to evaluate and come up with three proposals for actions to create a better working environment for spot welding as well as to limit exposure to welding fumes generated during welding of copper. An exposure measurement of air pollutants during welding of copper was done to evaluate copper exposure compared to threshold limit values of substances in welding fume. Exposure measurements were made with personal monitors. In addition, measurement with stationary equipment and measurement with directreading instruments. The use of protective equipment and ventilation were studied. In connection with measurements interviews were made.   The results of exposure measurements showed that the occupational exposure limit value for copper was exceeded considerably during the spot welding with the MIG welding process. The threshold limit value of copper is 0,2 mg/m3 and the highest value measured was 1,05 mg/m3, measured outside the welding shield. Based on observations on the use of personal protective equipment it has been noted that protective equipment is available but not used to desired extent. Three control actions are proposed; (1) routines to change the respiratory protective equipment filter regularly, (2) start using local exhaust integrated in the welding gun to a greater extent and (3) improve the ventilation in the plate shop by installing displacement ventilation. The calculated costs for two of the actions, action (1) and (2), fulfill the company's payoff principle of 3 years.   The thesis will contribute to making all employees in the plate shop aware of the risks that the work involves exposure to welding fumes. But even that they think of their own and others' safety and health in their daily work and adopt measures that effectively reduce exposure to welding fumes. To invest in a good working environment involves costs, such as protective and risk education. However, this should not be viewed as a cost but rather that it is an investment in the long run, that improve employee health and performance at work. In conclusion: To invest in a good physical and psychosocial work environment is an investment to get an efficient and profitable business!