scholarly journals Experimental investigation of operating and dynamic properties of adsorption filter prototype

2012 ◽  
Vol 10 (1) ◽  
pp. 51-62
Author(s):  
Miomir Raos ◽  
Ljiljana Zivkovic ◽  
Amelija Djordjevic ◽  
Jasmina Radosavljevic ◽  
Emina Mihajlovic
Keyword(s):  
Occupational Safety ◽  
Dynamic Properties ◽  
Ventilation System ◽  
Gas Mixture ◽  
Pressure Drops ◽  
Thermal Operating ◽  
Original Apparatus ◽  
And Performance ◽  
Ventilation Setup ◽  
Filter Prototype

The aim of the paper is an examination of flow-thermal, operating and dynamic properties (velocities of gas mixture, flows, pressure drops, temperature, humidity, chemical pollutants tests, and efficiency) and performance of the adsorption filter prototype in the filter-ventilation system. The paper presents the results of the experimental research conducted on the original apparatus in the laboratory for air quality management at the Faculty of Occupational Safety in Nis. The examination of flow-thermal, operating and dynamic parameters of the observed filter prototype was carried out on an experimental ventilation setup with a variable flow rate of gas mixture. Experimental data were registered with appropriate measuring equipment, which helped us obtain a picture of the behavior of the adsorption filter prototype compared to simulated parameters of the gas mixture. By measuring and data acquisition, we reached the assumptions for identifying the observed process, and thus the possibility of modeling and controlling process parameters.

Occupational Safety and Health of Laundry Employees in Hotel Industry

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Ankush Ambardar
Keyword(s):  
Occupational Safety ◽  
Chemical Exposure ◽  
Occupational Safety And Health ◽  
Health Issues ◽  
Employee Safety ◽  
Employee Protection ◽  
Chemical Hazards ◽  
Safety And Health ◽  
Day To Day Operations ◽  
And Performance

Employee safety and health is considered to be one of the major important human resource functions for any hotel organization. The current paper focuses on the application of occupational safety and health of laundry employees looking at the nature of the tasks performed in day to day operations. OSH is one of the significant factors responsible for employees inspiration and moreover retention in a hotel organization. Health, safety and performance of the employees are dependent on understanding and application of ergonomic practices followed during laundry operations. The paper explores laundry employee protection against various critical factors such as injuries, accidents, work postures, chemical exposure, heat, fire, noise, etc. A questionnaire was used to perpetuate perception of laundry employees in regard to protection from factors concerning safety and health issues from hotels of India. The results reveal that some of the OSH practices are been followed in hotels, while some were missing from hotels such as training, periodical audit and protection against chemical hazards. The present study suggests need for adopting OSH practices and enforcing periodical check for the same in every hotel besides of its categorization.

A Computational Analysis of Flow Field in Twin-Track Subway Tunnel to Improve Air Quality

2013 ◽  
Vol 319 ◽  
pp. 599-604
Author(s):  
Makhsuda Juraeva ◽  
Kyung Jin Ryu ◽  
Sang Hyun Jeong ◽  
Dong Joo Song
Keyword(s):  
Air Quality ◽  
Computational Model ◽  
Stokes Equations ◽  
Ventilation System ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
Navier Stokes ◽  
Subway Tunnel ◽  
Air Supply ◽  
And Performance

A computational model of existing Seoul subway tunnelwas analyzed in this research. The computational model was comprised of one natural ventilationshaft, two mechanical ventilationshafts, one mechanical airsupply, a twin-track tunnel, and a train. Understanding the flow pattern of the train-induced airflow in the tunnel was necessary to improve ventilation performance. The research objective wasto improve the air quality in the tunnel by investigating train-induced airflow in the twin-track subway tunnel numerically. The numerical analysis characterized the aerodynamic behavior and performance of the ventilation system by solving three-dimensional turbulent Reynolds-averaged Navier-Stokes equations. ANSYS CFX software was used for the computations. The ventilation and aerodynamic characteristics in the tunnel were investigated by analyzing the mass flowrateat the exits of the ventilation mechanicalshafts. As the train passed the mechanical ventilation shafts, the amount of discharged-air in the ventilationshafts decreased rapidly. The air at the exits of the ventilation shafts was gradually recovered with time, after the train passed the ventilation shafts. The developed mechanical air-supply for discharging dusty air and supplying clean airwas investigated.The computational results showed that the developed mechanical air-supplycould improve the air quality in the tunnel.

Obesity Research in Occupational Safety and Health

2016 ◽  
Vol 60 (1) ◽  
pp. 1022-1026 ◽  
Author(s):  
Mahboobeh Ghesmaty Sangachin ◽  
Lora A. Cavuoto
Keyword(s):  
Work Performance ◽  
Occupational Safety ◽  
Occupational Injury ◽  
Occupational Safety And Health ◽  
Future Research ◽  
Current State ◽  
Safety And Health ◽  
And Performance ◽  
General Studies ◽  
Future Work

Obesity is an emerging health problem among the workforce. This review examined the published literature in the last decade presented in prominent human factors and occupational safety and health journals to map out the current state of the research and direct future work. Overall, 44 studies were identified, out of which 27% focused on general effects of obesity on work performance, disability or occupational injury and 73% studied hypotheses regarding the effect of obesity on functional capacity, balance and performance of specific tasks. While over 90% of general studies suggest some significant adverse effect, only ~47% of specific studies report such results. While obesity co- occurs with chronic conditions such as diabetes or cardio-respiratory issues, laboratory based studies which exclude subjects with comorbidities may fail to fully manifest obesity effects. With only four studies identified that investigated an interaction of obesity with other personal or job-related health risks, future research in this regard is warranted.

An Experimental Procedure for Determining Both the Density and Flow Rate From Pressure Drop Measurements in a Cylindrical Pipe

2008 ◽  
Vol 130 (9) ◽  
Author(s):  
Ghislain Michaux ◽  
Olivier Vauquelin ◽  
Elsa Gauger
Keyword(s):  
Reynolds Number ◽  
Flow Rate ◽  
Pressure Change ◽  
Gas Mixture ◽  
Gas Extraction ◽  
Cylindrical Pipe ◽  
Flow Area ◽  
Number Range ◽  
Experimental Procedure ◽  
Pressure Drops

An experimental procedure was developed for determining both the density and flow rate of a gas from measurements of pressure drops caused by an abrupt flow area contraction in a cylindrical pipe. Experiments were carried out by varying the density and flow rate of a light gas mixture of air and helium, spanning a Reynolds number range from 0.2×104 to 3.4×104. From experimental results, a procedure was then proposed for evaluating the density from pressure change measurements in the scope of light gas extraction experiments.

Numerical and Mechanistic Modelling of Two-Phase Liquid-Gas Flow’s Pressure Drop Across Sharp-Edged Orifices

2019 ◽  
Author(s):  
Zurwa Khan ◽  
Reza Tafreshi ◽  
Matthew Franchek ◽  
Karolos Grigoriadis
Keyword(s):  
Numerical Model ◽  
Pressure Drop ◽  
Relative Error ◽  
Two Phase Flow ◽  
Mechanistic Model ◽  
Gas Mixture ◽  
Phase Flow ◽  
Two Phase ◽  
Pressure Drops ◽  
Phase Liquid

Abstract Pressure drop estimation across orifices for two-phase liquid-gas flow is essential to size valves and pipelines and decrease the probability of unsafe consequences or high costs in petroleum, chemical, and nuclear industries. While numerically modeling flow across orifices is a complex task, it can assess the effect of numerous orifice designs and operation parameters. In this paper, two-phase flow across orifices has been numerically modeled to investigate the effect of different fluid combinations and orifice geometries on pressure drop. The orifice is assumed to be located in a pipe with fully-developed upstream and downstream flow. Two liquid-gas fluid combinations, namely water-air, and gasoil liquid-gas mixture were investigated for different orifice to pipe area ratios ranging from 0.01 to 1 for the superficial velocity of 10 m/s. Volume of Fluid multiphase flow model along with k-epsilon turbulence model were used to estimate the pressure distribution of liquid-gas mixture along the pipe. The numerical model was validated for water-air with mean relative error less than 10.5%. As expected, a decrease in orifice to pipe area ratio resulted in larger pressure drops due to an increase in the contraction coefficients of the orifice assembly. It was also found that water-air had larger pressure drops relative to gasoil mixture due to larger vortex formation downstream of orifices. In parallel, a mechanistic model to directly estimate the local two-phase pressure drop across orifices was developed. The gas void fraction was predicted using a correlation by Woldesemayat and Ghajar, and applied to separated two-phase flow undergoing contraction and expansion due to an orifice. The model results were validated for different orifices and velocities, with the overall relative error of less than 40%, which is acceptable due to the uncertainties associated with measuring experimental pressure drop. Comparison of the developed numerical and mechanistic model showed that the numerical model is able to achieve a higher accuracy, while the mechanistic model requires minimal computation.

Numerical Simulation of the Flow Field for Rotor Ventilation System of Large-Scale Nuclear Power Turbo-Generator

2012 ◽  
Vol 152-154 ◽  
pp. 1498-1504 ◽  
Author(s):  
Xiao Hu Zhang ◽  
Lei Hu ◽  
Jian Hua Yuan ◽  
Yi Chao Yuan
Keyword(s):  
Flow Field ◽  
Nuclear Power ◽  
Large Scale ◽  
Ventilation System ◽  
Flow Distribution ◽  
Basic Unit ◽  
Turbo Generator ◽  
Key Issues ◽  
Computational Fluid Dynamics Cfd ◽  
And Performance

The nuclear power turbo-generator with large capacity is a basic unit of nuclear power plant, while the cooling technology becomes one of the key issues which affect its design and operation deeply. Axial-radial ventilation structure for rotor is commonly used in large nuclear power generator. In this article, according to the basic principles of computational fluid dynamics (CFD), ventilation’s structure and performance is analyzed, 3D flow model is also established. After the boundary conditions are determined, the numerical calculation and analysis is finished. And then, the rules of flow distribution is obtained, the flow field and the static pressure character of the gap is also computed, which could be very important to the ventilation system of the whole generator.

Optimization of Thermal Stability of Atrium Based on Computational Modeling

2016 ◽  
Vol 861 ◽  
pp. 353-360
Author(s):  
Aleš Rubina ◽  
Pavel Uher ◽  
Petr Blasinski
Keyword(s):  
Thermal Stability ◽  
Air Conditioning ◽  
Computer Modelling ◽  
Ventilation System ◽  
Air Conditioning System ◽  
Indoor Space ◽  
Central Air Conditioning ◽  
And Performance ◽  
Thermal Stability Of ◽  
Occupied Zone

The article deals with analysis of the heat balance and temperature microclimate of indoor space of a four-storey building atrium. With regard to the anticipated thermal loads in all functionally connected rooms, investor made a request to verify the thermal stability of the atrium before the implementation stage. Atrium and adjacent rooms are a geometrically complicated inner space which cannot be solved by analytical methods to ensure the required temperature conditions in occupied zone. This led to the creation of a mathematical model of the atrium with the current project solution. The result of the simulation of the existing solutions is that there is not complied desired air temperature in the occupied zone. For this reason, it was developed optimization of existing variant. Optimization was performed in steps as changing temperature of the central air conditioning system, changing number of units and performance of local refrigeration air conditioning. The conclusion of this paper is to evaluate the thermal profiles of temperature stratification in the atrium area and request the required cooling performance of the ventilation system. The article attempts to use computer modelling as a tool for the placement and performance design of ventilation equipment.

scholarly journals RESEARCH OF OPERATIONAL AND DYNAMIC PROPERTIES OF RUBBER FOR PRODUCTS WORKING IN SEA WATER

2020 ◽  
Vol 63 (11) ◽  
pp. 96-102
Author(s):  
Evgeniy N. Egorov ◽  
Nikolay I. Kol'tsov ◽  
Nikolay F. Ushmarin ◽  
Sergey I. Sandalov
Keyword(s):  
Sea Water ◽  
Dynamic Properties ◽  
Physical And Mechanical Properties ◽  
Standard Samples ◽  
Rubber Mixture ◽  
The Third ◽  
Industrial Oil ◽  
And Performance ◽  
Type Studies ◽  
Modifying Additive

The article studies the effect of trans-polynorbornene, general and special-purpose rubbers and fillers on the vulcanization characteristics of a rubber mixture, physical, mechanical, operational and dynamic properties of vulcanizates based on butadiene methylstyrene caoutchouc. The investigated model rubber mixture included SKMS-30ARK rubber, sulfur, 2,2'-dibenzthiazole disulfide, guanide F, zinc white, stearic acid, phenyl-2-naphthalamine, N-isopropyl-N'-phenyl-para-phenylenediamine, carbon blacks of grades P 514 and N 220, shungite powder and other ingredients. The rubber mixture was produced on laboratory rolls LB 320 160/160. The first (basic) version of the rubber mixture contained industrial oil I-12A as a softener. The second version of the mixture contained a modifying additive based on trans-polynorbornene and industrial oil I-12A. The third, fourth and fifth versions were prepared on the basis of a combination of rubbers SKMS-30ARK, SKN-4065 and BK-1675, including a modifying additive, as well as polyisobutylene P-118 and sevilen 11808-340. The vulcanization characteristics of the rubber mixture were studied on an MDR 3000 Basic rheometer at 150 °C for 30 min. To determine the physical and mechanical properties of rubber, standard samples of all variants of the rubber mixture were vulcanized at a temperature of 143 °C for 30 min in a vulcanization press of the P-V-100-3RT-2-PCD type. Studies of the physical, mechanical, operational and dynamic properties of rubber were carried out in accordance with the existing standards for the rubber industry. It is shown that vulcanizates containing a modifying additive have lower values of conventional tensile strength, hardness and tear resistance compared to vulcanizate of the base version of the rubber mixture and are characterized by increased dynamic and performance properties. Rubber containing a combination of butadiene-nitrile, butadiene-methylstyrene caoutchoucs and butyl caoutchouc, 10.0 mass parts sevilen 11808-340, 20.0 mass parts of trans-polynorbornene composed of in the modifying additive and 55.0 mass parts of carbon black P 324, possesses improved physical, mechanical and dynamic properties, as well as high resistance in sea water.

In-Mine Experimental Investigation of Temperature Rise and Development of a Validated Thermal Simulation Model of a Mobile Refuge Alternative

2015 ◽  
Author(s):  
Lincan Yan ◽  
David Yantek ◽  
Pete Bissert ◽  
Mark Klein
Keyword(s):  
Simulation Model ◽  
Air Temperature ◽  
Occupational Safety ◽  
Ventilation System ◽  
Thermal Simulation ◽  
Mine Safety ◽  
Test Results ◽  
Health Administration ◽  
Safety Research ◽  
Safety And Health

Mine Safety and Health Administration (MSHA) regulations require underground coal mines to use refuge alternatives (RAs) to provide a breathable air environment for 96 hrs. One of the main concerns with the use of mobile RAs is the heat and humidity buildup inside the RA. The accumulation of heat and humidity can result in miners suffering heat stress or even death. To investigate this issue, the National Institute for Occupational Safety and Health (NIOSH) conducted testing on a training ten-person, tent-type, RA in its Safety Research Coal Mine (SRCM) in a test area that was isolated from the mine ventilation system. The test results using sensible and latent heat showed that the average measured air temperature within the RA increased by 20.6°F (11.4°C) and the relative humidity approached 90 %RH. The test results were used to benchmark a thermal simulation model of the tested RA. The validated thermal simulation model predicted the average air temperature inside the RA, at the end of 96 hours, to within 1°F (0.6°C) of the measured average air temperature.

EFFECTS OF VENTILATION SETUPS ON AIR FLOW VELOCITY AND TEMPERATURE FIELDS IN BUS PASSENGER COMPARTMENT

2015 ◽  
Vol 77 (30) ◽  
Author(s):  
Noor Emilia Ahmad Shafie ◽  
Haslinda Mohamed Kamar ◽  
Nazri Kamsah
Keyword(s):  
Flow Velocity ◽  
Air Temperature ◽  
Numerical Study ◽  
Air Flow ◽  
Ventilation System ◽  
Temperature Fields ◽  
Passenger Compartment ◽  
Three Dimensional Model ◽  
Air Flow Velocity ◽  
Ventilation Setup

A bus compartment requires a good ventilation system to provide sufficient fresh air and a uniform air flow to passengers. This article presents a numerical study using CFD method to investigate the effects of using different ventilation setups on the air flow velocity and temperature distributions inside a passenger bus. Fluent software was used to develop a simplified three-dimensional model of a quarter section of a bus passenger compartment. Turbulent flow simulation was carried out based on a standard k-epsilon model to predict the distributions of air temperature and velocity inside the passenger compartment. The effects of two ventilation setups, namely mixing and displacement ventilations on the air temperature and air flow velocity distribution were also examined. Results of CFD simulations show that the displacement ventilation setup results in more uniform distribution of air flow velocity and air temperature inside the bus passenger compartment.

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