Fume Extraction Research Articles

Quantifying relevant exposure determinants and conditions of use for welding emissions

Background Conditions of Use (CoU) defines the operational conditions and risk management measures that result in adequately controlled exposure. It is mandatory to provide CoUs in Exposure Scenarios for the REACH legislation. CoU assessment based on similar exposure groups is a case-specific approach and not very efficient. We demonstrate how to quantify relevant exposure determinants and find optimal CoUs for welding using probabilistic exposure modelling. Methods Single and two-compartment models were applied to calculate exposure levels under specified conditions for five welding processes with the highest emissions. Model performance was tested using independently reported emissions and two field measurement studies. Results Welding fume concentrations were predicted within the range of 0.93 to 3.4 times the measured levels for three different welding scenarios, where two scenarios were repeated with four and five different ventilation rates. CoUs were quantified for welding with five different electrodes when welding is performed without controls, with a fume extraction torch, and with local exhaust ventilation. The exposure level was adequately controlled for three electrodes when controls were applied. Exposure assessment refinement proposals were given based on the relevant exposure determinants. The maximum emission factor was calculated for total fume emissions. A proposal for emission labelling was established. Conclusions CoU quantification was successfully demonstrated for total welding fume emissions. CoU results can be applied for welding processes where emissions are less than specified for the operational conditions specified here. Only total fume emissions were considered here, which may not be the limiting factor for risk; volatile and individual metal emissions were not considered. The approach applies to point sources for which emissions are adequately characterized. CoU assessment can be used to develop emission labelling and process specific safety actions. Compared to the traditional case-specific approach, modeling using this general approach will provide a significantly improved cost-effectiveness.

Evaluation of the air quality and the thermal comfort in the kitchen fume environment under the fresh air supplement

Kitchen cooking particles can severely deteriorate indoor environment, aggravating the risk of cardiovascular and cerebrovascular diseases, as well as respiratory diseases. In view of the severe hazard of cooking particles to human health, this paper numerically studies the trajectory and deposition of the cooking particles in the kitchen environment based on a numerical model. Also, quantitative evaluations for the air quality and thermal comfort are performed, hoping to provide a useful reference for the control of kitchen air pollution. Firstly, a kitchen environment simulation model is established based on Fluent. A post-processing UDF program for evaluating the effectiveness of fume absorption is developed. The reliability of the numerical model is verified by comparing the results of the fume concentration with those by the cooking experiments. Using this numerical model, the fume extraction effectiveness of the range hood under different velocities of the fresh air is analyzed comprehensively, including particle trajectory, air age, temperature, PMV (Predicted Mean Vote), and PPD (Predicted Percentage of Dissatisfied) indicators. Results have shown that high speed of the fresh air can cause a strong blowing sensation, deteriorating indoor air quality. The PMV and PPD values around the human body show a parabolic trend. Generally, the relatively low fresh air speed can achieve satisfactory air quality and thermal comfort while saving energy consumption.

Evaluation of the effectiveness of fume extraction systems in arc welding

Evaluation of the effectiveness of fume extraction systems in arc welding

Design and Computational Fluid Dynamics Analysis of a Fume Extraction System for a Welding Company in Guyana

The arc welding operation results in harmful fumes being emitted where welders are exposed to dangerous metallic gases and fumes for 6 to 8 hours daily at INFAB welding company in Guyana. This paper presents a design of a fume extraction system, the design incorporates workspace dimensions, volume calculations, duct materials required, framework materials, airflow requirements, and fan selection, guided by a target of 6 air changes per hour (ACH). In addition, the calculated required airflow rate of 58,500 ft³/h ensures the selection of appropriate fans. The design aims to create a safe and healthy welding area for the employees by removing harmful fumes. Computational fluid dynamics (CFD) simulations were employed to analyse velocity and pressure distribution, offering valuable insights into airflow patterns and pressure variations.

Influences of home kitchen designs on indoor air quality

Kitchen indoor air quality (IAQ) has not been well-addressed amongst other IAQ problems at home, despite the fact that cooking is one of the major home activities that can generate high levels of respirable particles and gaseous air pollutants. This study aims at investigating the effects of home kitchen designs on the performance of various ventilation strategies in reducing exposure to IAQ pollutants. The degree of natural ventilation was found to be dependent largely on the relative position of window and door opening, and using mixed ventilation with natural cross-ventilation and mechanical ventilation did not necessarily provide better ventilation. Natural ventilation with the added fume extraction by the exhaust fan could not protect the occupants from high levels of cooking pollutants. Range hood on the other hand could quickly and locally remove particles and gaseous cooking pollutants from the source. The study recommends using a range hood alone during cooking or with single-side natural ventilation to maintain an acceptable IAQ in the home kitchen.

Managing Fume & Dust Filtration

Management of dust and fume extraction in the additive manufacturing (AM) industry must be considered to minimise the impact and control emissions. Joshua Evans, applications engineer and head of BOFA Academy at BOFA International, explains more

Determination of Arrhenius parameters for advanced kinetic model used in CFD modeling of the wood pellet combustion process

With the increased popularity of using wood stoves for household heating in recent years, numerous experimental research projects have been launched with the goal of generating cleaner and more efficient stove designs. This work is focused on mathematical modeling of combustion process in low-power residential heating appliance (small-scale stove) fuelled by different wood pellets (WP1-Beech (hardwood) and WP2-Pine (softwood)). Kinetic model scheme that encompasses determination of Arrhenius parameters was proposed for applied Finite rate/Eddy Dissipation approach. Types of wood pellets have been combusted on the experimental stand which is equipped with a set of temperature sensors and exhaust analyzer. A comparison of results obtained from combustion in the heating unit has been performed to find relations between established kinetics of devolatilization for various wood pellets and to determine exhaust composition, arising from oxidation reactions. Numerical modeling using computational fluid dynamics (CFD) has been performed for the char and CO oxidations to supplement the experimental results. Due to limitations on installed stove such as poor design, air supply, fume extraction, or heat exchanger can lead to excessive CO emissions or lower energy efficiency. Outcomes show that it is crucial to minimize unused stove volume and to enhance gaseous mixing for reduction of CO emissions, while maintaining sufficiently high temperatures for supporting fast oxidation reactions. Results of comparisons of conducted analyses can be useful in areas related to process optimization and improvement of combustion and devolatilization reaction conditions in the small scale heating units.

From welding point to clean air

When a Netherlands-based manufacturer wanted to safeguard its workforce from welding fumes, it turned to a specialist in filter systems for the metal processing sector. It recommended welding fume extraction using high-vacuum systems with connected extraction torches.

Evaluation of a Continuous Laser Ablation Coating Removal Device for Steel Bridges

One common method for removing deteriorated coatings from steel bridges is abrasive blast cleaning. Although effective, abrasive blast cleaning can be hazardous to operators and must be conducted using expensive containment. One innovative solution to the hazardous nature and high expense of blast cleaning is laser ablation coating removal (LACR). LACR uses a high-energy laser, rather than conventional blasting, to remove the coating and has the potential to minimize operator hazards and eliminate the need for containment. The purpose of this study was to evaluate a continuous LACR system in relation to its coating removal effectiveness, industrial hygiene (IH), and effect on the steel substrate below the underlying coating. Coating removal and IH evaluation were performed on coated steel samples, including some with lead and other toxic metal coatings. LACR was also performed on bare steel, used to perform mechanical testing, such as tension, fatigue, hardness, and microstructural analysis to evaluate the effect of LACR on a steel substrate. In comparison to the pulsed LACR system evaluated in a previous study, the continuous LACR system was 2–27 times faster at removing most coatings, but it was unable to remove white coatings like the pulsed LACR system was able to do. IH evaluation showed that the continuous LACR system was likely to generate toxic metal fumes when ablating lead coatings, but this could possibly be minimized by designing an attached fume extraction system. Mechanical testing showed that the continuous LACR had no detrimental effects to the steel substrate.

Assessment of LoRaWAN Transmission Systems Under Temperature and Humidity, Gas, and Vibration Aging Effects Within IIoT Contexts

Within the big picture of the Internet of Things (IoT), a brand new paradigm has risen since few years ago in the context of industrial scenarios: the industrial IoT (IIoT), whose aim is to transplant all of the features, characteristics, and scopes of the IoT into industrial settings. The latter ones might be subject to a wide range of environmental conditions from the point of view of both temperature and relative humidity, along with harmful gases exposure and vibration due to, for instance, machinery. Therefore, whenever their monitoring is performed by means of devoted infrastructures, such extreme working conditions must be born in mind during the pertaining design phases. Mostly, industrial monitoring is put into effect by resorting to wireless sensor networks (WSNs) enabled by low-power wide area network (LPWAN) technologies. This set of facilities includes an ample heterogeneity of standards and techniques. However, the long-range (LoRa) modulation and the LoRa wide area network (LoRaWAN) protocol extensively proved to be reliable and robust alternatives. Thus, in this article, the variations of hardware performances of a LoRaWAN sensor node, in terms of transmission capabilities, due to the changes of temperature and relative humidity, vibration, and gaseous atmospheres, such as CO, NO, and NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , which are typical of industrial processes, are investigated. In so doing, an aging process due to the aforementioned phenomena was induced. To this end, a measurement campaign within controlled environments (i.e., a climatic chamber, a fume extraction plant, and an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ad hoc</i> vibration test bench) was sorted out, whose results show a physiological performances drop that neither undermines the network reliability nor damages the sensor node electronics.

How to Reduce the Exposure of Welders to an Acceptable Level: Results of the InterWeld Study.

Workplace measurements in the past have shown that the applicable occupational exposure limits (OELs) are regularly exceeded in practice when high-emission welding processes are applied. The InterWeld pilot study was planned as part of an intervention study to show under which conditions compliance with the OEL is achievable in gas metal arc welding (GMAW) with solid wire. The investigation focussed on local exhaust ventilation, i.e. captor hoods and welding torches with integrated fume extraction. Forty tests with hand-guided GMAW were configured by experts with regard to all technical parameters and carried out by a professional welder. Effects of protective measures and process parameters on the exposure to respirable welding fumes and airborne manganese (Mn), chromium, nickel, and hexavalent chromium were investigated. Personal sampling was carried out in the welder's breathing zone outside the face shield at high flow rates (10 l min-1) in order to achieve sufficient filter loading. Particle masses and welding fume concentrations were determined by weighing the sampling filters. Metal concentrations were analysed by inductive coupled plasma mass spectrometry. In order to evaluate the effects on exposure, the measurements were performed under similar conditions. The data were analysed descriptively and with mixed linear models. For measurements below the limit of detection, the exposure level was estimated using multiple imputation. Two to five times higher exposures to respirable welding fumes and airborne metals were observed during welding of 10 mm sheets than during welding of 2- or 3-mm sheets. Welding fume and Mn exposure were reduced by 70 and 90% when on-torch extraction or a captor hood was applied. Other airborne metals were reduced to a similar extent. Modifications on welding parameters led to a reduction of exposure against respirable particles by 51 up to 54%. Although proper extraction at the point of origin and lower-emitting process variants ensure a drastic reduction in exposure, compliance with current OELs is not guaranteed. In order to ensure adequate health protection, especially at workplaces where thick sheets with long relative arc times are processed, there is a need for technical development.

Energy conservation at high power consuming holding furnace with modified coil design and electrical circuits

This paper deals with high energy consuming induction holding furnace. The improved version of coil design along with additional electrical interlocks and alarm, modified hydraulic controls, strengthening mechanical structures and energy saving proposals at holding furnace fume extraction system ensures trouble free operation of furnace and hence continuity of production at all the planned plant operational days. This project involves in purchasing of D-section copper extruded coil from Europe–Switzerland for its extended length from existing 3 meters long to 9 Meters which enables in reduction of coil joints. The performance of the holding furnace has improved in terms ofits energy consumption per ton of liquid metal. The payback period for the estimated investment will be less than 2 years.

A Critical Review on Fume Extraction System for Pipe and Plate Welding

In general, for both pipe and plate welding fixtures plays a crucial role. The current study investigates exposure among welders employed in the shop floor area. This welding fumes extractor has a exhaust ventilation setup to track sensitivity to welding fumes using glass fiber filter paper. The trick to acquiring the most effective system fitted to the closed atmosphere so that the gases do not disperse beyond the welding chamber is by learning the fundamentals of ventilation and airborne contaminant extraction. In previous tests, fixtures outside the fumigation hood were installed for both pipe and platform welding. By using a lathe chuck with 4 jaws fixed at both ends that keep the pipe up to 30 mm in diameter, a basic concept of the fixture is constructed. A horizontal rotating stand that is movable only in the y-axis can be set according to the area to be welded without any deflections. This device will be rotated with minimum speed, where the welding can be done effectively without press and dislocations. The main vision is to control the welding fumes in a closed chamber and to fabricate a lightweight fume extraction hood with pipe and plate welding fixtures. This research comes up with good social benefits to reduce blowout of fumes in industries and visibility during welding.

Direct Exposure of Welders to Welding Fumes and Effect of Fume Extraction Systems Under Controlled Conditions.

Welding fume exposure of welders occurs either directly from the welding process and sputters or from the fume background within the workshop. In this study the contribution of fume originating directly from the welding process was assessed. Exposure was quantified by measuring the time integral of fume mass concentration using a tapered element oscillating micro balance connected to a welder dummy. Direct fume exposure was highest for welding processes with low fume emission rates and lowest for processes with high fume emission rates. This finding is supposed to be due to the higher energy input of high emitting processes which stabilizes the thermic column and therefore eliminates fume particles from the welder's breathing zone. Exposure can be minimized by additionally optimizing workshop ventilation.

Optimal Design of Secondary Fume Extraction Systems in Ferroalloys Production: from Principles to Operation

In ERAMET Norway AS (ENO) as one of the world’s largest producers of different grades of high manganese alloys, sustainable operation has always been a priority. There are therefore continuous activities in different plants of ENO in order to reduce environmental footprints of our operations. One of the main areas of focus in such activities has been reducing diffuse emissions through design and implementation of efficient fume extraction systems based on a systematic approach. Optimal design of secondary fume extraction systems in ferroalloys industry has always been challenging. The main reason for this, is the diffuse nature of emissions which are generated from different metallurgical processes. Although design of fume capturing systems based on principles of diffuse emissions extraction is the key for high performance capturing of generated fumes from molten slag and metal but there are several operational details, practical aspects and external parameters which should be taken care of them while making an industrial design. These aspects may cause deviation of a design from its ideal conditions because of the need for necessary modifications of the design. In order to make optimal design for secondary fume extraction systems with, having full overview on practical and operational aspects, applying industrial competences, using process information and operational data and applying proper modelling methods to evaluate performance of the system at each st ep, from initial idea to final design, are of great importance. In this work, principles for design of efficient secondary fume extraction systems, main reasons of deviation from best design in the industry and ENO’s practice based on the systematic approach for making an optimal design considering all operational restrictions, is presented.

Erosion Damage to Impeller of Welding Fume Extraction System

Abstract Even very simple cases of component failure can represent an enrichment for this section Failure Analysis. Besides the instructive value of an easily understandable content, they allow those failure analysts becoming acquainted with the field to gradually get to know the most important material-related mechanisms governing component failure cases. A look back by the authors on the section Failure Analysis of Practical Metallography cases revealed only one single erosion failure case in the past 10 years. It won't therefore do any harm to address this interesting failure mechanism once again. The erosion failure of a fan impeller presented in this article was very easily solved However, it was rather unexpected. Who would have considered it possible that an air extraction system in a factory workshop is subject to such high erosive distress? Hence, the main message of this short article is that the experts tasked with investigating the component failures should be very thorough and propose all sorts of damage hypotheses, sometimes even those which, at first glance, appear unlikely, and may only reject them when the examination results indicate the contrary.

Hospital care in Departments defined as COVID-free: A proposal for a safe hospitalization protecting healthcare professionals and patients not affected by COVID-19.

The COVID-19 pandemic influenced the normal course of clinical practice leading to significant delays in the delivery of healthcare services for patients non affected by COVID-19. In the near future, it will be crucial to identify facilities capable of providing health care in compliance with the safety of healthcare professionals, administrative staff and patients. All the staff involved in the project of a Covid-free hospital should be subjected to a diagnostic swab for COVID-19 before the beginning of healthcare activity and then periodically in order to avoid the risk of contamination of patients during the process of care. The modifications of various activities involved in the process of care are described: outpatient care, reception of inpatients, inpatient ward and operating room. For outpatient care, modality of appointment procedure, characteristics of waiting room and personal protective equipment (PPE) for healthcare professionals and administrative staff are presented. Reception of inpatients shall be conditional on a negative swab for COVID-19 obtained with a drive-in procedure. The management of the operating room represents the most crucial step of the patient's care process. The surgical team should be restricted and monitored with periodic swabs; surgical procedures should be performed by experienced surgeons according to standard procedures; surgical training experimental treatments and research protocols should be suspended. Adequate personal protective equipment and measures to reduce aerosolization in the operating room (closed circuits, continuous cycle insufflators, fume extraction) should be adopted. Prevention of possible transmission of the virus during procedures in open, laparoscopic and endoscopic surgery is to use a multi-tactic approach, which includes correct filtration and ventilation of the operating room, the use of appropriate PPE (FFP3 plus surgical mask and protective visor for all the staff working in the operating room) and smoke evacuation devices with a suction and filter system. on behalf of the UrOP Executive Committee Giuseppe Ludovico, Angelo Cafarelli, Ottavio De Cobelli, Ferdinando De Marco,Giovanni Ferrari, Stefano Pecoraro, Angelo Porreca, Domenico Tuzzolo.

Enabling condition based maintenance in a precious metal processing plant

In precious metal processing plants, suitable maintenance systems should be deployed to provide the necessary plant operating conditions, ensure plant availability and provide critical fume extraction and filtration systems for health and safety. A key focus for this work was use of sensors to monitor and predict abnormal equipment behaviour and examining how the data obtained could be processed into information and better inform the condition monitoring systems. The requirement for this research was driven by escalating maintenance costs in an industrial case study in South Africa. Historical records on equipment failure and was used in Pareto analysis to define the critical assets and failure modes for equipment that dominated the escalating maintenance costs for the industrial case study. Vibration data from mounted sensors was then collected the identified critical assets, analysed and used to infer condition of critical assets. Statistical tools based on process capability index values for processes in control and out of control were defined for tracking system deterioration and enabling predictive maintenance. The results show that sensors and thresholds based on process capability index can be used in predictive maintenance to alert maintenance teams to attend to vacuum pumps and fans pre-failure and hence improve plant availability and operation and reduces cost.

Computational fluid dynamics (CFD) modelling on effect of fume extraction

In anodizing industries, fume hoods are essential at the workplace since long term exposure to the acid fumes released may lead to adverse health effect. The design of fume hood is always referring to the guidelines in ACGIH’s Industrial Ventilation: A Manual of Recommended Practice, yet there is no definitive validation regarding the guidelines stated in the manual. A numerical simulation using Computational Fluid Dynamics (CFD) was conducted to study the effective region of a slot fume hood. With assumption on that turbulence in the suction hood does not affect the slot velocity, the model of simulation focus only on the cross-sectional area of slot entry. From the results, it is clear that the effective region of a slot fume hood with designated exhaust air flow rate is more than half the width and height of solution tank. Meanwhile from the case studies, further increasing the slot velocity of a single slot fume hood is capable to reduce more hazardous fume form the work place, but it is not as effective as using two fume hoods. Two fume hoods can reduce the concentration of fume to a value below the permissible threshold limit with better power efficiency and cost effective.

Donaldson seals BOFA purchase

Donaldson Co Inc has completed its acquisition of an 88% stake in UK fume extraction system specialist BOFA International Ltd (see Filtration Industry Analyst, September 2018).