Design of a new gas-dynamic stabilization system for a metal-cutting plasma torch

Abstract The analysis of the influence of various design solutions of the gas-dynamic stabilization system in plasma torches for cutting metals on the efficiency of equalizing the velocities of gas flows along the cross-section of the gas path is carried out. It is noted that the efficiency evaluation method developed by the authors should be based on the calculation of the uniformity of the gas flow velocity distribution over the cross-section of the gas-air path of the plasma torch. A vortex stabilization system using two swirlers is proposed. The effect of improving the reliability and quality of plasma cutting is shown. The results of the efficiency studies for the proposed system of gas-vortex stabilization in metal-cutting plasma torches are presented. The calculating results of equalization coefficients for the velocity distribution in different parts of the gas-dynamic stabilization system in the plasma torch are presented. Based on the results of the calculations, a constructive optimization of the gas-air path in the plasma torch was performed. The experimentally obtained advantages of the new upgraded plasma torch in terms of the gas-vortex stabilization efficiency are demonstrated. The effects of improved cutting quality and reduced nozzle wear in the new plasma torch are shown. This is due to the higher degree of the plasma arc stabilization in the new plasma torch, which leads to a decrease in its oscillations, and, consequently, to an increase in the efficiency of the cutting process.

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Development and research of new technologies for precision plasma cutting of metals

Ferrous Metallurgy Bulletin of Scientific Technical and Economic Information ◽

10.32339/0135-5910-2021-7-829-834 ◽

2021 ◽

Vol 77 (7) ◽

pp. 829-834

Author(s):

S. V. Anakhov ◽

Yu. A. Pykin ◽

A. V. Matushkin ◽

B. N. Guzanov

Keyword(s):

Plasma Torch ◽

Metal Cutting ◽

New Technologies ◽

Arc Discharge ◽

Experimental Studies ◽

Carbon Steels ◽

Plasma Cutting ◽

Medium Thickness ◽

Plasma Torches ◽

Gas Dynamic

Plasma torches of Russian origin concede to import metal-cutting plasma facilities by several parameters, in particular energy efficiency, quality of cut, degree of automation. To increase efficiency and safety of domestic electro-plasma technologies itь is necessary to perfect methods of analysis of known design solutions to provide new developments. The results of the plasma torches design widely used in metallurgical and machine-building technologies for air-plasma cutting of metals presented. It was noted that productivity, cutting quality and reliability of plasma equipment should be chosen as the main criteria of efficiency for plasma cutting technology. It was shown that special attention should be paid to improving the gas-vortex stabilizing method for the plasma forming gas, which ensures the efficiency of both the plasma torch and the plasma cutting process as a whole. Results of studies of a complex system for arranging the flow of plasma-forming gas through the channels of the gas-air path in the plasma torch and the subsequent creation of new systems for stabilizing the arc discharge of metal cutting DC plasma torches with high technological capabilities presented. The study was carried out by the methods of numerical simulation of gas-dynamic and thermo-physical processes for various designs of plasma torches. Optimized designs of plasma torches with various variants of gas-vortex stabilization systems were elaborated. A series of elaborated torches, which includes a single-stream plasma torches ПМВР-5 for precision cutting of medium thickness metals, as well as two-stream plasma torches ПМВР-9 for cutting metals of small and medium thicknesses presented. The last plasma torches use the technology of narrow-jet or compressed plasma and have no domestic analogues. A methodology of metal-cutting plasma torches designing by gas-dynamic, thermo-physical and acoustic criteria was elaborated. The results of experimental studies showed that the use of new ПМВР-5 plasma torches allows to obtain precision cuts corresponding to the 1st and 2nd quality classes according to GOST 14792-80 on steels of the 09Г2С type of medium thickness. It was also shown that the use of new plasma torches makes it possible to perform precision finishing plasma cutting on low-carbon steels of medium thickness (without additional mechanical processing of the cutting edge) in the production technologies of welded joints.

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Influence of plasma torch design on cutting quality during precision air-plasma cutting of metal

Izvestiya Ferrous Metallurgy ◽

10.17073/0368-0797-2020-2-155-162 ◽

2020 ◽

Vol 63 (2) ◽

pp. 155-162

Author(s):

S. V. Anakhov ◽

B. N. Guzanov ◽

A. V. Matushkin ◽

N. B. Pugacheva ◽

Ya. A. Pykin

Keyword(s):

Plasma Torch ◽

Dynamic Stabilization ◽

Quality Analysis ◽

Metallographic Analysis ◽

Plasma Cutting ◽

Plasma Arc ◽

09G2s Steel ◽

Plasma Torches ◽

Gas Dynamic

Optical interferometry and metallographic analysis were used to study structure of cutting seams obtained after 09G2S steel cutting by PMVR-5 plasma torch. These plasma torches have a number of design features in the system of gas-dynamic stabilization of plasma arc. It is shown that application of new plasma torch allows obtaining higher quality of cutting 09G2S steel of medium thickness with high productivity and lower energy costs. Metallographic analysis has shown that qualitative composition of the cut surface structure is almost the same, so priority criteria for comparative quality analysis are parameters of surface microgeometry. Evaluation of this parameter shows high quality of cutting almost along the entire length of a cut, since the influence of technological features of plasma arc cut into the metal affects at a distance of less than 0.3 mm from the edge of the sheet. The use of additional methods of gas-dynamic stabilization in PMVR -5.2 plasma torch (feed symmetry with a double swirl system of plasma-forming gas) allows to achieve additional advantages in terms of surface quality compared to PMVR -5.1. A number of features that affects quality of cut when cutting metals of different thicknesses for welding, is noted depending on the angle of inclination of plasma torch during cutting. Estimates of the surface layer hardness indicate minimal deviations from the requirements of GAZPROM Standard 2-2.4-083 (instructions on welding technologies in the construction and repair of field and main gas pipelines), which allows further use of cutting seams obtained by studied plasma torches for welding without removing zones of thermal influence. Thus, application of new plasma torches makes possible precision finishing plasma cutting of metals, including production of welded joints.

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Gas-dynamic aspects of new metal-cutting plasmatron design

Science intensive technologies in mechanical engineering ◽

10.30987/2223-4608-2021-5-7-13 ◽

2021 ◽

Vol 2021 (5) ◽

pp. 7-13

Author(s):

Sergey Anakhov ◽

Anatoliy Matushkin ◽

Yuriy Pykin

Keyword(s):

Flow Rate ◽

Gas Flow ◽

Metal Cutting ◽

Dynamic Stabilization ◽

Plasma Cutting ◽

Gas Flow Rate ◽

Gas Dynamic ◽

Design Solutions ◽

The Impact

The analysis of the impact of different design solutions for the system of plasmatron gas-dynamic stabilization for metal-cutting upon effectiveness of gas flow rate balance according to the section of a gas path is carried out. A system of turbulent stabilization, using two swirlers is offered. The effect of plasma cutting reliability and quality is shown.

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About Raising of the Gas Vortex Stabilization Efficiency in Plasma Torch for Metal Cutting

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.284.218 ◽

2018 ◽

Vol 284 ◽

pp. 218-223

Author(s):

A.V. Matushkin ◽

Yu.A. Pyckin ◽

S.V. Anakhov ◽

I.Y. Matushkina

Keyword(s):

Plasma Torch ◽

Metal Cutting ◽

Gas Distribution ◽

Gas Dynamic ◽

Distribution Uniformity ◽

Dynamic Filters ◽

The One

Influence of gas distribution uniformity in the channels of air-gas paths on efficiency and quality of metals cutting is noted for plasmatrons of various updating. It is shown, that application of gas-dynamic filters promotes efficiency and quality of plasmatrons with the one-line scheme of air-gas pathswork. The technique for estimation of gas distribution uniformity in the channels of metal-cutting plasmatron is presented.

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A practical evaluation method of seismic stresses developed in the cross section of shield tunnels.

Doboku Gakkai Ronbunshu ◽

10.2208/jscej.1991.437_193 ◽

1991 ◽

pp. 193-202

Author(s):

Yukio SHIBA ◽

Susumu OKAMOTO

Keyword(s):

Cross Section ◽

Evaluation Method ◽

Practical Evaluation ◽

The Cross

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On the distribution of velocity in a viscous fluid over the cross-section of a pipe, and on the action at the critical velocity

Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character ◽

10.1098/rspa.1905.0021 ◽

1905 ◽

Vol 76 (509) ◽

pp. 205-216 ◽

Cited By ~ 6

Keyword(s):

Viscous Fluid ◽

Velocity Distribution ◽

Critical Velocity ◽

Cross Section ◽

Viscous Fluids ◽

Stream Line ◽

The Subject ◽

The Cross ◽

The Stability ◽

Lord Kelvin

1. Introduction .—An expression for the velocity at which stream-line motion breaks down in cylindrical pipes has been obtained by Osborne Reynolds, and together with many others he has measured the fall of pressure occurring in different lengths. Lord Kelvin, Lord Rayleigh, and Reynolds have investigated the stability of different kinds of flow for viscous and non-viscous fluids, but how nearly the theoretical conditions of velocity distribution actually occur has not hitherto formed the subject of research. Experiments have often been made on the variation of mean linear velocities in the eddying state, but when the motion is irrotational, these are too low to admit of accurate measurement by any method so far employed. The objects of the present paper are to determine these velocities, to investigate the change which takes place at the critical velocity, and to find the relation between the velocity and the pressure to which it gives rise in a “ Pitot ” gauge of the form used.

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Gas dynamic generator of the annular intensity distribution in the cross section of a laser beam

Journal of Applied Spectroscopy ◽

10.1007/bf02606572 ◽

1995 ◽

Vol 62 (1) ◽

pp. 91-93

Author(s):

B. B. Vilenchits ◽

A. A. Zhdanovskii ◽

D. S. Umreiko

Keyword(s):

Laser Beam ◽

Cross Section ◽

Intensity Distribution ◽

Gas Dynamic ◽

The Cross ◽

Dynamic Generator

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A New Approach to the Demonstration of Oxidase-Localization Using Tannic Acid Or Catechin

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100073933 ◽

1973 ◽

Vol 31 ◽

pp. 698-699

Author(s):

V. Mizuhira ◽

Y. Futaesaku

Keyword(s):

Cross Section ◽

Tannic Acid ◽

Elastic Fiber ◽

The Other ◽

New Approach ◽

Tissue Block ◽

Active Reaction ◽

The Cross

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.

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Energy Distribution in Electron Beams

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100096096 ◽

1972 ◽

Vol 30 ◽

pp. 568-569

Author(s):

Tamotsu Ohno

Keyword(s):

Electron Beam ◽

Energy Distribution ◽

Cross Section ◽

Integral Curve ◽

Electron Beams ◽

Electron Gun ◽

Angular Divergence ◽

Apparent Increase ◽

Integral Width ◽

The Cross

The energy distribution in an electron; beam from an electron gun provided with a biased Wehnelt cylinder was measured by a retarding potential analyser. All the measurements were carried out with a beam of small angular divergence (<3xl0-4 rad) to eliminate the apparent increase of energy width as pointed out by Ichinokawa.The cross section of the beam from a gun with a tungsten hairpin cathode varies as shown in Fig.1a with the bias voltage Vg. The central part of the beam was analysed. An example of the integral curve as well as the energy spectrum is shown in Fig.2. The integral width of the spectrum ΔEi varies with Vg as shown in Fig.1b The width ΔEi is smaller than the Maxwellian width near the cut-off. As |Vg| is decreased, ΔEi increases beyond the Maxwellian width, reaches a maximum and then decreases. Note that the cross section of the beam enlarges with decreasing |Vg|.

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