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Impact and Forecasting of Additive Manufacturing
Published in Manu Srivastava, Sandeep Rathee, Sachin Maheshwari, T. K. Kundra, Additive Manufacturing, 2019
Manu Srivastava, Sandeep Rathee, Sachin Maheshwari, T. K. Kundra
One point of similarity of AM and conventional manufacturing techniques is that both consume material as well as energy. Also, emission generation is common in both cases. These emissions are hazardous to a large extent to health as well as occupation, depending upon their intensity as discussed here. Traditional manufacturing techniques like casting, machining, forging, welding, etc. result in numerous kinds of water/air emissions, fluid spills, noise, wasted chips and so on which have potentional health hazards [3]. One of the prime factors is oil mist which is a resultant of metal working fluids. Long exposure to different kinds of oil mist can cause several kinds of cancer and other diseases. Noise is also a common hazard which can result in occupational hearing loss. Thus, there are several such kinds of hazards which can come from the use of conventional manufacturing techniques. These kinds of hazards can be eliminated with the use of AM techniques. AM, on the other hand, leads to newer health issues.
Accident and disease prevention in working life: Common grounds and areas for mutual learning
Published in Stein Haugen, Anne Barros, Coen van Gulijk, Trond Kongsvik, Jan Erik Vinnem, Safety and Reliability – Safe Societies in a Changing World, 2018
E. Albrechtsen, R.B. Jørgensen, T.Ø. Kongsvik, K.V.H. Svendsen
Work at height will also involve significant occupational hygiene risk. From an occupational hygiene perspective it is well known that tunnel workers are exposure to both particulate and gaseous air pollution and that tunnel workers are known to be at increased risk of long-term and short–term lung function decline and CORP (Ulvestad et al.). Different activities causes different exposures to these workers. Exposure to gases and particles from diesel emissions has been considered to be among the dominating burdens during tunnel construction due to weel-going diesel machines; also during drilling and blasting operations, workers are exposed to dust, with α-quartz as the most important agent. α-quartz in the dust from tunnels varies between <1% and more than 50% (Norwegian Tunnelling Society,Publication No.13) and α-quartz exposure may lead to COPD. Exposure to oil mist and oil vapour is another type of exposure that may also occur during drilling. Exposure to oil mist may cause occupational asthma and also pulmonary fibrosis (Robertson et al., 1988) Risk assessment hence have to be performed with focus on all these possible exposures.
Fabrication and Processing of Biodegradable Mg and Its Alloys
Published in Yufeng Zheng, Magnesium Alloys as Degradable Biomaterials, 2015
The generated heat is one of the main problems for Mg alloy machining, which may lead to ignition of the chips. Several kinds of coolants are used to reduce the surface temperature of the Mg alloy. In contact with water-based coolants, Mg tends to have chemical reactions and form hydrogen, which is extremely flammable. Oil-based lubricants introduce the danger of oil mist explosions. However, Salahshoor and Guo (2013) used dual-purpose oil, serving as both lubricant and coolant during the ball-burnishing process on Mg-0.8Ca alloy, which can effectively reduce the temperature, indicating only a 5-6°C increase in the applied pressure range. Pu et al. (2012a) compared the influence of dry and cryogenic machining (spraying the liquid nitrogen on the machined surface) using different cutting-edge radius tools on the surface integrity of AZ31B alloy, and the cryogenic machining with a large cuttingedge radius could lead to the desired surface finish.
A newly developed dilution system for optical particle size and concentration measurements in oil-injected screw compressors
Published in Aerosol Science and Technology, 2023
Johannes C. Deichmann, Christian Straube, Jobst Eisengräber-Pabst, Thomas Grein, Jörg Meyer, Achim Dittler
The two dilution systems were validated in terms of formation of secondary aerosol and their transfer functions by measuring an oil mist aerosol without and with the dilution systems installed. The setups for the validation are shown in Figure 3. A tempered oil atomizer was used as a particle generator for validation. The atomizer was tempered in water to 20 °C, while laboratory temperatures were between 14 and 20 °C. The atomizer was held manually at a constant differential pressure. The generated oil mist was mixed with particle-free compressed air controlled by a critical orifice. The critical orifice was selected to achieve a number concentration in the aerosol low enough to be measured undiluted by the Palas welas 2070 HP at low coincidence levels, yet high enough to allow reasonable time periods for diluted measurements. The goal was set to 200,000 particles/cm³. The excess part of the volume flow after mixing was filtered and discarded. The residual volume flow passed through a heating hose. The heating hose was either turned off leading to measurements at room temperature or set to 80 °C. The heating hose was either connected directly to the OPC sensor or to one of the dilution systems, which, in turn, were then connected to the OPC sensor.
An analytical investigation on energy efficiency of high-speed dry-cutting CNC hobbing machines
Published in International Journal of Sustainable Engineering, 2018
Among these types of systems, the regularity of energy consumption is quite similar; this also applies to the power equation of the dust absorption system (), the silo system (), and the freeze-drying system ().Oil mist separation system.
Machining and optimization of the external diamond burnishing operation
Published in Materials and Manufacturing Processes, 2023
The oil mist having a diameter of fewer than 2.5 μm (the particulate matter 2.5-PM 2.5) can suspend in the working environment and easily participate in the lungs as well as the bloodstream.[18] The mixture results in air pollution and damages the health of the workers. Therefore, minimization of the PM 2.5 is an urgent demand to obtain safe air.