EXPERIMENTAL METHODS OF ASSESSING THE EFFICIENCY OF USE OF SMOKE AND HEAT REMOVAL

2020 ◽  
Vol 1 (2) ◽  
pp. 22-28
Author(s):  
S Semichaevskiy ◽  
V Prisyazhnuk ◽  
M Yakimenko ◽  
M Osadchuk ◽  
O Kurtov ◽  
...  
Keyword(s):  
Operating Time ◽  
Research Work ◽  
Experimental Studies ◽  
Heat Removal ◽  
Heat Extraction ◽  
Rescue Work ◽  
Temperature Reduction ◽  
Reduction Coefficient ◽  
Functional Layout

The results of the experimental studies on the determination of the smoke reduction coefficient and the temperature reduction coefficient during the implementation of three variants of gas-air environment normalization in the test box are presented, namely during the creation of a smoky and high-temperature environment and subsequent self-reduction of the smoke time. smoke and heat removal by injection of air and by simultaneous supply of air and sprayed at the water jet to the test box using portable portable smoke and heat removal. A large number of firefighting cases are associated with the hazardous effects on the personnel of hazardous fire factors. In particular, the effects of high temperatures and smoke greatly complicate rescue work and firefighting. An important tactical way to reduce such an impact on the personnel of the fire and rescue units is to control the flue streams of the fire by means of portable means of smoke and heat removal, which are functionally intended for local increase of air pressure by injection of air into the area of ​​work of personnel or removal of products from the mountains. fire conditions for normalization of temperature and air environment. At present, there are almost no portable means of smoke and heat removal in the fire-fighting units of the State Emergency Service of Ukraine. Considering that in the period from 2014 to 2018 during the firefighting and elimination of the consequences of emergencies in Ukraine, there was a tendency to increase the number of used units of gas and fire protection service from fires from 5802 to 7804 and increase their operating time from 1704 h to 2544 h. the need for widespread use of fire and rescue units and portable means of smoke and heat removal. n order to assist in solving this problem, a functional layout of a portable smoke and heat extraction type was created at the Ukrainian Research Institute of Civil Protection within the framework of the research work "Smoke and Heat Removal Means". According to the developed methodology, the experts of the institute conducted experimental studies to determine the smoke reduction coefficient and the temperature reduction coefficient in the fire room during the use of such means. The results of the experimental studies are presented in the appropriate graphs.

EXPERIMENTAL AND NUMERICAL INVESTIGATION ON MANUFACTURING METHODS OF POWDER METALLURGY COMPONENTS WITH INTEGRATED INFORMATION STORAGE

2011 ◽  
Vol 10 (01) ◽  
pp. 11-20
Author(s):  
BERND-ARNO BEHRENS ◽  
NAJMEH VAHED ◽  
EDIN GASTAN ◽  
FABIAN LANGE
Keyword(s):  
Research Work ◽  
Experimental Studies ◽  
Information Storage ◽  
Research Centre ◽  
Specific Data ◽  
Data Carrier ◽  
Foreign Materials ◽  
The Impact ◽  
Sintering Processes

This paper presents a research work within Collaborative Research Centre 653 "Gentelligent Components in Their Lifecycle." The term "gentelligent" refers to the genetic and intelligent character of these components. Specific data are inherently saved in the components, which are used during its lifecycle for the means of identification, processing, and reproduction. The present study aims at the development of a method to manufacture and utilize gentelligent sintered parts. As data carrier, foreign materials shaped in fonts, logos, or codes are embedded in the powder material proceeded by pressing and sintering processes. The foreign material can be applied in forms of particles or compound powder. The information read-out is based on radiographic methods. The objectives of the investigations are the determination of the process parameters of each method and the impact of the integrated foreign materials on the mechanical properties of the component. The experimental studies are supported by numerical simulations.

Manufacturing Method of PM Components with Integrated Information Storage

2010 ◽  
Vol 44-47 ◽  
pp. 915-919 ◽  
Author(s):  
Bernd Arno Behrens ◽  
Najmeh Vahed ◽  
Edin Gastan ◽  
Fabian Lange
Keyword(s):  
Research Work ◽  
Experimental Studies ◽  
Information Storage ◽  
Research Centre ◽  
Specific Data ◽  
Manufacturing Method ◽  
Foreign Materials ◽  
The Impact ◽  
Sintering Processes

This paper presents a research work within Collaborative Research Centre 653 “Gentelligent Components in Their Lifecycle”. The term “gentelligent” refers to the genetic and intelligent character of these components. Specific data are inherently saved in the components which are used during its lifecycle for the means of identification, processing and reproduction. The presented study aims for the development of a method to manufacture and utilize gentelligent sintered parts. As data carrier, foreign materials shaped in fonts, logos or codes, are embedded in the powder material proceeded by pressing and sintering processes. The foreign material can be applied in forms of particles or compound powder. The information read-out is based on radiographic methods. The objectives of the investigations are the determination of the process parameters of each method and the impact of the integrated foreign materials on the mechanical properties of the component. The experimental studies are supported by numerical simulations.

Heat Transfer Studies in Ejector-induced Downflow Bubble Column

2016 ◽  
Vol 14 (5) ◽  
pp. 955-964
Author(s):  
Rohit B. Meshram ◽  
Gautam Kundu ◽  
Dibyendu Mukherjee
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Liquid Velocity ◽  
Bubble Column ◽  
Research Work ◽  
Experimental Studies ◽  
Heat Removal ◽  
Axial Position ◽  
The Heat Transfer Coefficient

Abstract Temperature control in bubble columns is of great importance, since chemical reactions in many of the chemical, pharmaceutical, fertilizer, etc. industries are usually accompanied by heat supply or heat removal operations. In the present research work, the heat transfer coefficient of a two-phase co-current vertical downflow bubble column (i.d. 0.05 m×1.6 m height) was evaluated. Experimental studies were carried out to calculate the heat transfer coefficient for operating temperature ranges from 60 °C to 90 °C. The effects of the superficial gas velocity (4.25×10–3 to 9.58×10–3 m/s), liquid velocity (8.50×10–2 to 16.98×10–2 m/s), gas holdup, and axial position were investigated. Empirical correlation was developed, based on a multiple regression analysis to calculate a heat transfer coefficient as a function of dimensionless numbers, including the Reynolds number, the Prandtl number, and the Froude number.

Improvement Of Curvilinear Diagrams Of Concrete Deformation

2019 ◽  
pp. 99-104
Keyword(s):  
Reinforced Concrete ◽  
Peak Load ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
Significant Difference ◽  
Deformation Diagrams

Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.

INFLUENCE OF HEAT TREATMENT OF MOUNTAIN MASSIVE ON TEMPERATURE MODE OF GEOTHERMAL CIRCULATION SYSTEM

2018 ◽  
pp. 44-50
Author(s):  
Yu. P. Morozov
Keyword(s):  
Heat Transfer ◽  
Operating Time ◽  
Fluid Motion ◽  
Coolant Temperature ◽  
Circulation System ◽  
Thermal Processes ◽  
Temperature Mode ◽  
Heat Influx ◽  
Stationary Heat Transfer

Based on the solution of the problem of non-stationary heat transfer during fluid motion in underground permeable layers, dependence was obtained to determine the operating time of the geothermal circulation system in the regime of constant and falling temperatures. It has been established that for a thickness of the layer H <4 m, the influence of heat influxes at = 0.99 and = 0.5 is practically the same, but for a thickness of the layer H> 5 m, the influence of heat inflows depends significantly on temperature. At a thickness of the permeable formation H> 20 m, the heat transfer at = 0.99 has virtually no effect on the thermal processes in the permeable formation, but at = 0.5 the heat influx, depending on the speed of movement, can be from 50 to 90%. Only at H> 50 m, the effect of heat influx significantly decreases and amounts, depending on the filtration rate, from 50 to 10%. The thermal effect of the rock mass with its thickness of more than 10 m, the distance between the discharge circuit and operation, as well as the speed of the coolant have almost no effect on the determination of the operating time of the GCS in constant temperature mode. During operation of the GCS at a dimensionless coolant temperature = 0.5, the velocity of the coolant is significant. With an increase in the speed of the coolant in two times, the error changes by 1.5 times.

Energetic properties of peat saturated with petroleum products

2020 ◽  
Vol 13 (2) ◽  
pp. 105-109
Author(s):  
E. S. Dremicheva
Keyword(s):  
Crude Oil ◽  
Diesel Fuel ◽  
Energy Use ◽  
Experimental Studies ◽  
Calorific Value ◽  
Petroleum Products ◽  
Ash Content ◽  
Motor Oil ◽  
Initial Sample

This paper presents a method of sorption using peat for elimination of emergency spills of crude oil and petroleum products and the possibility of energy use of oil-saturated peat. The results of assessment of the sorbent capacity of peat are presented, with waste motor oil and diesel fuel chosen as petroleum products. Natural peat has been found to possess sorption properties in relation to petroleum products. The sorbent capacity of peat can be observed from the first minutes of contact with motor oil and diesel fuel, and significantly depends on their viscosity. For the evaluation of thermal properties of peat saturated with petroleum products, experimental studies have been conducted on determination of moisture and ash content of as-fired fuel. It is shown that adsorbed oil increases the moisture and ash content of peat in comparison with the initial sample. Therefore, when intended for energy use, peat saturated with petroleum products is to be subjected to additional drying. Simulation of net calorific value has been performed based on the calorific values of peat and petroleum products with different ratios of petroleum product content in peat and for a saturated peat sample. The obtained results are compared with those of experiments conducted in a calorimetric bomb and recalculated for net calorific value. A satisfactory discrepancy is obtained, which amounts to about 12%. Options have been considered providing for combustion of saturated peat as fuel (burnt per se and combined with a solid fuel) and processing it to produce liquid, gaseous and solid fuels. Peat can be used to solve environmental problems of elimination of emergency spills of crude oil and petroleum products and as an additional resource in solving the problem of finding affordable energy.

EXPERIMENTAL STUDIES OF REINFORCED CONCRETE STRUCTURES WITH CROSS-SHAPED SPATIAL CRACK UNDER TORSION WITH BENDING

2020 ◽  
Vol 92 (6) ◽  
pp. 13-25
Author(s):  
Vl.I. KOLCHUNOV ◽  
◽  
A.I. DEMYANOV ◽  
M.M. MIHAILOV ◽  
◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Experimental Determination ◽  
Calculation Method ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Design Parameters ◽  
Reinforced Concrete Structures ◽  
Experimental Scheme

The article offers a method and program for experimental studies of reinforced concrete structures with cross-shaped spatial crack under torsion with bending, the main purpose of which is to check the design assumptions and experimental determination of the design parameters of the proposed calculation method. The conducted experimental studies provide an opportunity to test the proposed calculation apparatus and clarify the regularities for determining deflections, angles of rotation of extreme sections, and stresses in the compressed zone of concrete. For analysis, the article presents a typical experimental scheme for the formation and development of cracks in the form of a sweep, as well as characteristic graphs of the dependence of the angles of rotation of end sections.

Preliminary Studies on the Determination of FLD for Single Point Incremental Sheet Metal Forming

2012 ◽  
Vol 504-506 ◽  
pp. 863-868 ◽  
Author(s):  
Miklos Tisza ◽  
Péter Zoltán Kovács ◽  
Zsolt Lukács
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
New Technologies ◽  
Single Point ◽  
Research Work ◽  
Dimensional Accuracy ◽  
Forming Limit ◽  
Incremental Sheet Metal Forming

Development of new technologies and processes for small batch and prototype production of sheet metal components has a very important role in the recent years. The reason is the quick and efficient response to the market demands. For this reasons new manufacturing concepts have to be developed in order to enable a fast and reliable production of complex components and parts without investing in special forming machines. The need for flexible forming processes has been accelerated during the last 15 years, and by these developments the technology reaches new extensions. Incremental sheet metal forming (ISMF) may be regarded as one of the promising developments for these purposes. A comprehensive research work is in progress at the University of Miskolc (Hungary) to study the effect of important process parameters with particular emphasis on the shape and dimensional accuracy of the products and particularly on the formability limitations of the process. In this paper, some results concerning the determination of forming limit diagrams for single point incremental sheet metal forming will be described.

Determination of Heat Input in Tungsten Inert Gas and Laser Welding of Type Optim 960 QC Structural Steel Using Adams’ Equation for 2-D Heat Distribution

2017 ◽  
Vol 750 ◽  
pp. 45-52
Author(s):  
Sveto Cvetkovski
Keyword(s):  
Laser Welding ◽  
Heat Input ◽  
Arc Welding ◽  
Research Work ◽  
Laser Beam Welding ◽  
Peak Temperature ◽  
Efficiency Coefficient ◽  
Zone Recrystallization ◽  
Welding Processes

The heat input during conventional arc welding processes can be readily calculated knowing the power taken from the power source. The efficiency coefficient can be taken from the appropriate literature standards. Here, the intention of the performed research work was to develop a procedure for determination of heat input in arc and laser welding processes implementing Adams equation - modified Rykalin equation for two dimensional heat distributions (2-D). To realize this idea, it is necessary to determine two characteristic temperatures points in the HAZ with known peak temperature, and to determine distance between them. Implementing measured values for distance in Adams’ equation, heat input in arc welding can be directly determined in arc welded joints.In laser beam welding, the absorption of the beam in the metal is not known, so that the welding heat input cannot be calculated directly, and direct implementation of Adam’s equation is not possible i.e. absorption coefficient has to be determined first, and after that calculation of heat input is possible.The peak temperatures corresponding to specific microstructures can be obtained by performing welding simulation, by the Gleeble 1500 simulator in our case. As one of the peak temperatures, the melting temperature can be used corresponding to the fusion line, so that at least one characteristic peak temperature such as coarse grain zone, fine grin zone, intercritical zone, recrystallization, has to be determined by the simulation.Performed research showed that obtained values for heat input using Adam’s equation correspond pretty well with standard equation for heat input in arc welding.

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