Cleaning Air Streams from Fine Particles in Paint Booths

2021 ◽  
Vol 25 (12) ◽  
pp. 10-14
Author(s):  
R.Ya. Bikkulov ◽  
O.S. Dmitrieva ◽  
A.V. Dmitriev ◽  
G.R. Badretdinova
Keyword(s):  
Flow Regime ◽  
Centrifugal Force ◽  
Fine Particles ◽  
Separation Zone ◽  
Small Diameter ◽  
Separation Device ◽  
Rectangular Shape ◽  
High Speeds ◽  
Dispersed Particles ◽  
Air Streams

To solve the problem of increasing the efficiency of cleaning the exhaust air of painting chambers from fine particles, a separation device with elements of a square and rectangular shape has been developed and described by the principles of its operation. A method for calculating the design dimensions of the developed separation device is presented. Different versions of the height of the separation zone are considered, depending on the size of dispersed particles. It is shown that the device is able to capture particles smaller than 10 microns with an efficiency close to 100 %, provided they adhere to the walls. The peculiarity of the design of the separation device is that a set of small-diameter vortices is created, in which the flow regime is close to laminar, and to achieve large values of centrifugal force, it is not necessary to create high speeds in the crevices.

scholarly journals Separation of Fine Particles from Gas in Paint-Spraying Booths

2021 ◽  
Vol 346 ◽  
pp. 03070
Author(s):  
Rustem Ya. Bikkulov ◽  
Andrey V. Dmitriev ◽  
Vadim E. Zinurov ◽  
Guzel R. Badretdinova
Keyword(s):  
Gas Flow ◽  
Fine Particles ◽  
Solid Particles ◽  
Dust Particles ◽  
Technological Parameters ◽  
Separation Device ◽  
Dispersed Particles ◽  
Quality Of Products ◽  
The Impact

Nowadays, at production facilities with paint-spraying booths that use paint and varnish materials to cover the surfaces of product, the problem of gas flow contamination with finely dispersed solid particles of dust and rubbish, which negatively affect the quality of products, is increasingly being raised. In order to minimize the content of solid particles in the gas flow, coarse and fine filters are installed in the paint-spraying booths, which prevent dust particles from entering the surface of products. However, the existing purification devices have a number of disadvantages that affect the efficiency of collecting finely dispersed particles from the gas flow with a size of 0.5-5 microns. The authors of article developed a square separator to increase the efficiency of collecting finely dispersed particles from gas flows in the paint-spraying booths. The installation of proposed separation device in the paint-spraying booths affects not only the quality of collecting solid particles, but also increases the service life of fine and coarse filters In the course of numerical studies, the results of impact of structural and technological parameters, namely, the impact of inlet rate and scale of separation device on the efficiency of collecting solid particles from the gas flow, were obtained.

Non-Intrusive Optical Validation of Two-Phase Flow Regimes in a Small Diameter Tube

2014 ◽  
Author(s):  
Darin J. Sharar ◽  
Arthur E. Bergles ◽  
Nicholas R. Jankowski ◽  
Avram Bar-Cohen
Keyword(s):  
Film Thickness ◽  
Flow Regime ◽  
Two Phase Flow ◽  
Small Diameter ◽  
Flow Regimes ◽  
Phase Flow ◽  
Two Phase ◽  
Traditional Use ◽  
Adiabatic Flow ◽  
Flow Pattern Identification

A non-intrusive optical method for two-phase flow pattern identification was developed to validate flow regime maps for two-phase adiabatic flow in a small diameter tube. Empirical measurements of film thickness have been shown to provide objective identification of the dominant two-phase flow regimes, representing a significant improvement over the traditional use of exclusively visual and verbal descriptions. Use of this technique has shown the Taitel-Dukler, Ullmann-Brauner, and Wojtan et al. phenomenological flow regime mapping methodologies to be applicable, with varying accuracy, to small diameter two-phase flow.

Studying the Effect of Fine Particles of Tungsten Carbide on the Macro-Structure, Hardness and Microhardness of Gradient Steel Billets

2020 ◽  
Vol 986 ◽  
pp. 3-8
Author(s):  
Andrey N. Anikeev ◽  
Ilia V. Chumanov ◽  
Vadim Sedukhin
Keyword(s):  
Tungsten Carbide ◽  
Fine Particles ◽  
Centrifugal Casting ◽  
High Hardness ◽  
Chemical Compositions ◽  
Steel Sheets ◽  
Dispersed Particles ◽  
Steel Castings ◽  
Scientists And Engineers ◽  
Single Material

Creating a gradient of properties in a single material is challenging for scientists and engineers. For this purpose, such methods are used as: welding of steels of different chemical compositions, joint rolling of steel sheets, sealing and surfacing of various kinds. All of these methods have a big disadvantage: under load, the material is destroyed in the weakest place - the place where the layers join. In this article, the authors proposed to obtain a gradient of properties in steel castings due to the introduction of dispersed particles of tungsten carbide into the crystallizing melt during centrifugal casting. The particles introduced serve as crystallization centers, accelerate the crystallization process and increase certain types of mechanical properties (hardness, microhardness, tensile strength). In addition, the particles of tungsten carbide have high hardness; therefore, in the structure of the workpieces they serve as reinforcing elements that strengthen the structure. The uneven distribution of particles in the preform being formed is possible for two reasons: tungsten carbide has a density greater than the melt, and besides, centrifugal force acts on them. The article describes the experiment and its results on the production of metal preforms with a gradient of properties. The introduced particles significantly influenced the macro-structure of the prepared castings. The article also presents the results of a study of the effect of particles on the hardness and micro-hardness of the resulting blanks.

scholarly journals A HIGH SPEED VACUUM CENTRIFUGE SUITABLE FOR THE STUDY OF FILTERABLE VIRUSES

1936 ◽  
Vol 64 (4) ◽  
pp. 503-528 ◽  
Author(s):  
Johannes H. Bauer ◽  
Edward G. Pickels
Keyword(s):  
Centrifugal Force ◽  
Yellow Fever ◽  
High Speed ◽  
Yellow Fever Virus ◽  
High Vacuum ◽  
Fever Virus ◽  
Compressed Air ◽  
Frictional Heat ◽  
High Speeds ◽  
Very High

1. A high speed centrifuge is described in which the speed is limited only by the strength of the material of which the rotor is made. It carries sixteen tubes, each of which conveniently accommodates 7 cc. of fluid. 2. The centrifuge operates in a very high vacuum and therefore requires only a small amount of driving energy. The arrangement has been found to eliminate the possibility of producing injurious frictional heat. 3. The rotating parts are supported by anair-bearing and are driven by compressed air. 4. The centrifuge has been successfully operated at a speed of 30,000 revolutions per minute, representing a maximum centrifugal force in the fluid of 95,000 times gravity. 5 Celluloid tubes used for centrifugation of fluid at high speeds are described. 6. Experiments are described in which good sedimentation of the yellow fever virus was obtained.

Two-Phase Flow Regime Transitions in Microchannel Tubes: The Effect of Hydraulic Diameter

2000 ◽  
Author(s):  
John W. Coleman ◽  
Srinivas Garimella
Keyword(s):  
Flow Regime ◽  
Mass Flux ◽  
Two Phase Flow ◽  
Small Diameter ◽  
Flow Patterns ◽  
Hydraulic Diameter ◽  
Intermittent Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Mechanisms

Abstract An experimental investigation of two-phase flow mechanisms during condensation of refrigerant R134a in small diameter round and rectangular tubes was conducted. A 4.91 mm round tube, and four round tubes with hydraulic diameters ranging from 1 mm – 4 mm were studied to characterize the influence of tube miniaturization on the flow mechanisms. For each tube under consideration, flow mechanisms were recorded over the entire range of qualities 0 < x < 1, and for five different mass fluxes between 150 kg/m2-s and 750 kg/m2-s. Approximately 50 data points were recorded for each tube to obtain a comprehensive understanding of the effects of geometry, mass flux and quality on the phase-change flow mechanisms. The flow mechanisms were categorized into four different flow regimes: intermittent flow, wavy flow, annular flow, and dispersed flow. In addition, the large amount of data over a wide range of test conditions enabled the delineation of several different flow patterns within each flow regime, which provides a clearer understanding of the different modes of two-phase flow. Transition lines between the respective flow patterns and regimes on these maps were established based on the experimental data. It was found that the intermittent flow regime becomes larger as the tube hydraulic diameter is decreased. Also, the size of the wavy flow regime decreases for the small diameter tubes, and disappears completely for the 1 × 1 mm square tube. These maps and transition lines can be used to predict the flow pattern or regime that will be established for a given mass flux, quality and tube geometry.

A Numerical Investigation over the Cavitating Flow Regime of a 2D-Hydrofoil

2015 ◽  
Author(s):  
Luca Bonfiglio ◽  
Stefano Brizzolora
Keyword(s):  
Flow Regime ◽  
Leading Edge ◽  
Flow Speed ◽  
Cavitating Flow ◽  
Suction Surface ◽  
High Speeds ◽  
State Potential ◽  
America’S Cup ◽  
Sailing Boat ◽  
Stable Flow

The advances in sailing boat races have been greatly proven in the recent America’s Cup competition. Sailing boats have reached speeds above 40 knots with a simple concept: the wetted surface of the hull is minimized and the required displacement is obtained through a lifting force produced by submerged hydrofoils working at very high speeds. This is a well-known concept in naval architecture that has been exploited since the beginning of the 20th Century. Hydrofoils used in sailing boat races are yet not designed for cavitating flow, but major changes in the design will be needed in case speed increases above 50 knots. When highspeed crafts (including fast sailing boats) operate significantly above the planing threshold speed, the convenience of completely or partially supporting their weight by lifting hydrofoils is evident (Du Cane (1964)). A very low pressure field induced by high in flow speed triggers water vaporization at ambient temperature: cavitation cannot be avoided and foil shape has to be designed with the goal of maintaining a stable flow regime eventually com-promising the lift. When craft speed arise above 50 knots, the de-sign philosophy for the basic section of the lifting hydrofoil has to radically change and turn to super-cavitating hydrofoils (Auslaender [1962]) being the final goal addressed towards the delay and stabilization of the cavity shape over the hydrofoil surface. In super-cavitating regimes the suction surface of the hydrofoil is fully enveloped in the cavity which (typically) detaches at the leading edge of the foil and closes in the wake well aft the trailing edge. The pressure side of the hydrofoil is the only responsible for lift generation thus the main design target is represented by the shape of the foil surface. Several simplified theories assuming steady state potential flow (mentioned later in this introduction) were developed in the past to deal with this essential design problem.

scholarly journals Excitation of vertical coronal loop oscillations by impulsively driven flows

2018 ◽  
Vol 613 ◽  
pp. L3 ◽  
Author(s):  
P. Kohutova ◽  
E. Verwichte
Keyword(s):  
Kinetic Energy ◽  
Solar Corona ◽  
Centrifugal Force ◽  
Pressure Difference ◽  
Coronal Loop ◽  
Oscillatory Motion ◽  
Excitation Mechanism ◽  
Kink Mode ◽  
High Speeds ◽  
Mhd Simulations

Context. Flows of plasma along a coronal loop caused by the pressure difference between loop footpoints are common in the solar corona. Aims. We aim to investigate the possibility of excitation of loop oscillations by an impulsively driven flow triggered by an enhanced pressure in one of the loop footpoints. Methods. We carry out 2.5D magnetohydrodynamic (MHD) simulations of a coronal loop with an impulsively driven flow and investigate the properties and evolution of the resulting oscillatory motion of the loop. Results. The action of the centrifugal force associated with plasma moving at high speeds along the curved axis of the loop is found to excite the fundamental harmonic of a vertically polarised kink mode. We analyse the dependence of the resulting oscillations on the speed and kinetic energy of the flow. Conclusions. We find that flows with realistic speeds of less than 100 km s−1 are sufficient to excite oscillations with observable amplitudes. We therefore propose plasma flows as a possible excitation mechanism for observed transverse loop oscillations.

Sign in / Sign up

Export Citation Format

Share Document