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6value-based approach // Science and Education a New 12. Construction extension to the PMBOK®
Dimension, Economics. Humanities and Social guide. Project Management Institute, Inc. 2016. — 215 Sciences. VIII(40), Issue 232, 2020 - PP. 36-40. p. available at: http:// http://seanewdim.com/232.html
THE ANALYSIS OF CONDITIONS FOR SEPARATION OF LIQUID METAL DROPS FROM ELECTRODE ENDS AT ARC METALLIZATION WITHIN THE CONDITIONS OF A PULSATING
SPRAY FLOW EXPOSURE
Zakharova I.
Asst. Prof.
Royanov V.
Prof.
Serenko. A.
Prof.
Pryazovskyi State Technical University
Abstract
The main problem that arises when parts are restored by the arc metallization method is to improve the quality of coatings by reducing the negative impact of oxygen in the spraying airflow. To reduce the oxidizing effect of air-spraying flow on the liquid metal of electrodes the method of arc metallization utilizing the pulsating spraying flow, obtained by introducing an additional element - a valve of the pulsator into the spray system of electroarc metallizer, was previously introduced.
The nature of forces acting on the liquid metal of electrodes at melting by an electric arc without consideration of spraying flow is reviewed.
Taking into account the findings presented in the works of V.I. Dyatlov, B.E. Paton a diagram of liquid metal formation on the cathode and anode depending on the parameters of the electric arc mode without considering the impact of the spraying flow is presented.
Under the impact of a pulsating spraying flow, a drop of molten metal of the electrodes will turn into a half-ellipsoid shape. The impact and distribution of forces acting on a drop of such shape and conditions of separation of a drop from the electrode ends are important.
Analytical calculation of forces acting on a drop of semi-ellipsoid form during arc metallization with a pulsating spraying flow was carried out in this paper.
Keywords: spraying flow, aerodynamic force, surface tension force, spherical drop, semi-ellipsoid drop.
Articulation of issue. analysis of forces acting on a drop under the impact of pulsating airflow during arc metallization, conditions of drop separation from the electrode surface considering the airflow pulsation.
Analysis of recent publications. Some researches of scientists are focused on studying the processes of formation of liquid metal drops [6,7], but they mainly consider the drops of spherical shape and the force of aerodynamic resistance acting on them due to the airflow, or drops in " tongue" shape, which have a high probability of fragmentation and transition into spherical form.
Objective of the study. To perform an analytical calculation of forces acting on a drop of semi-ellipsoidal shape during arc metallization with pulsating spraying flow.
Statement of basic materials. In order to clarify the basic laws of electrode melting at electrode arc metallization with a pulsating spraying airflow [1,2,4,5], a mathematical model of the electrode melting process at the pulsating effect of the spraying airflow using the Mathcad software was proposed. The basic simulation scheme is presented in Fig. 1.
Analytical calculation of forces acting on a drop of ellipsoidal or spherical shape during arc metallization by a pulsating spraying flow.
Fig.1. Scheme of action of the main forces on a drop of ellipsoidal shape Fa - aerodynamic force; Fst - surface tension force; Fem - electromagnetic force, a,b,c - ellipsoid semiaxes.
The mass of molten metal of one electrode, the mass and volume of the liquid drop during an impulse and pause, considering the spraying losses, a burn-out loss is determined from the following expression:
me = Al' Fe -Y-
where me - molten electrode mass Al - electrode melting zone length Fe - cross-sectional area of the electrode Y - metal density, g/cm3
Then the mass of a drop of liquid metal is equal to:
md = an ■ me
where md - drop mass
an= 0,92- metal meltdown factor considering spraying losses, a burn-out, etc.
^=^
The volume of liquid metal drop equals
T'd
Yi
where Vd - drop volume
y- liquid metal density, yi = 7,0 •lO3, Kr/M3
Geometric dimensions of ellipsoid halves a,b, depend on electrode diameter and angle ae. The size of the third half-axis can be determined through the volume of the molten electrode respectively:
de
a = e
2 sin (ae )
b = ^.
2
1,5 V
d
c = — ta • b
where ae - electrode tilt angle
Let's determine the size of the volume-equivalent diameter of a spherical drop formed during the pulse and pause period:
dd =
6me
n-Yi
Let's determine the value of forces acting on a drop of liquid metal. The force of gravity: Fg=mg, H. To find the surface tension force acting in the opposite direction of the airflow, it is necessary to know the length of the conditional perimeter of the drop "sitting" on the electrode for the ellipsoidal Lel and spherical shapes
a — b
. then
4 =
a + b
L
el
n
( a + b )
( 64 - 3? )
( 64 -)
where Lel - the length of the conditional drop perimeter, in the case when Fst = CJ • Lei
—2
C = 12 • 10 H/m - surface tension coefficient
Taking into account the obtained expressions, we specify the scheme of forces for the case of formation of a semi-ellipsoid drop of liquid metal.
semi-ellipsoid drop
spherical drop
Fig. 2. Clarified scheme of forces during the formation of semi-ellipsoid and spherical liquid metal drops.
Determine the formation of a semi-ellipsoid and spherical drop of liquid metal for pulsating flow at the contact angle 0<n/2 and 0>n/2
We set the static contact angle for a spherical drop
6 = 40 -
n 180
, rad.
To find the perimeter of the circle contour of a drop spot, let's specify the dimensions shown in the picture
hd = 0,5dd (1 - cos(<9)), bd = 0,5dd • sin(6)
Spot contour circle perimeter: La = (t • de ) if 2bd ) de
L( = (ft • 2bd ) otherwise.
The force of surface tension is determined by the following expressions F( = 7 • L Let's determine the cross-sectional area of a drop Sc, which is subject to high-speed airflow
s, = ^ (ß - sin (ß )),
M2
2
where ßx = 2a COS
1
h
\
d
0,5d.
d
■ center angle for the drop circle
V ' d J
Let's determine the value and nature of aerodynamic force action for drops: Fa (t ) = Cd " Sc " Wld(,) - for a spherical drop
Fa (t) = Cd • Se • (w—^) ) - for a semi-ellipsoid drop
where Cd- drop resistance coefficient, Cj= 0,5
S = — ft • c • b e 2
On the basis of the equations above we obtain graphs of aerodynamic force and surface tension force for drops.
Fig .3 Comparison of aerodynamic (Fa) and surface tension forces (Fa) for drops.
As a result of program calculations, we obtain graphs of surface tension and aerodynamic force actions for a semi-ellipsoid drop of liquid metal.
Let's determine the value and nature of electromagnetic force action for spherical and semi-ellipsoid drops. Let's determine the density of welding current in the electrode and the drop spot:
I
I =
wd
7i • a • b
■ the density of welding current in the electrode,
I
le =
wd
~2 - the density of welding current in the drop spot
V 2 J
F = A ■ I
1 em A wd
1 + 2,3 ■ log
V A y y
where A=0,00510~5
Let's analyze the conditions of liquid metal drop tear-off from the electrode end for the case (conditionally) of surface tension and aerodynamic force interaction (without considering the electrodynamic force).
It is generally believed that the condition of a spherical or semi-ellipsoid drop being torn off from the electrode under the action of only the impulse airflow is fulfilled if the aerodynamic force (at any point in time) is greater than the surface tension force holding the drop.
The resulting force for a spherical drop is determined by the expression Frez (t) = Fa (t) — Fa
Based on the results of the program calculations we determine the value and nature of the resulting force for drops of spherical and semi-ellipsoidal shape in Fig.
Fig.4 Value and nature of the resulting force for the drops
To ensure separation of liquid metal, the ratio of the maximum at possible specific values of these forces is as follows:
F
—— = 10,104 - for a spherical drop
F
j
F„
F
= 56,44 - for a semi-ellipsoidal drop
j
The obtained ratios were considered at the development of pulsator and selection of parameters of arc metallization mode with pulsating spraying flow.
Summary
The conducted analytical research shows that even for very short (in terms of duration) impulses of the spraying flow the liquid metal drops are torn off from the electrode ends when the aerodynamic and electromagnetic forces exceed the level of surface tension force and have impulse character (that confirms the results of research given earlier in sections).
Ratios of maximum aerodynamic force to surface tension force causing separation of liquid metal from electrode ends at pulsating spraying flow are established:
F
—a = 10,104 - for a spherical drop
F<r
F
—a = 56,44 - for a semi-ellipsoidal drop
Fo
References
1. Iryna Zakharova The effect of a pulsating spraying jet on the volume of air that comes in contact with metal electrodes during arc metallization // Technium: Romanian Journal of Applied Sciences and Technology
2. Zakharova I.Development of equipment for arc metallization with pulsating spraying airflow to improve the technological properties of the coating// The scientific heritage (Budapest, Hungary) No 49 (2020)
3. Vyacheslav Royanov, Irina Zakharova, Mykyta Kriuchkov, Valeriy Chigarev Investigation of factors, determining dispersity of coating particlesat arc sputtering with pulsating spraying stream //world science, № 6(58), Vol.1, June 2020
4. Zakharova I.V. Teoretychni doslidzhennya ta praktychna rozrobka protsesu duhovoho napylennya z pul'suyuchym rozpylyuval'nym potokom povitrya z
metoyu pidvyshchennya yakosti pokryttiv / I.V Zakharova, V.O Royanov., O.M Serenko. // Innovative Technologies and Scientific Solutions for Industries Suchasnyy stan naukovykh doslidzhen' ta tekhnolohiy v promyslovosti - №1 (11) - 2020 - str.114-121.
5. Zakharova I Obgruntuvannya konstruktyvnyy osoblyvostey pul'satora dlya zabezpechennya pul'suyu-choho rozpylyuval'noho potoku povitrya pry duhoviy metalizatsiyi. / I. Zakharova, V Royanov., // «Tekhnolohichni nauky ta tekhnolohiyi», m. Cher-nihiv, -№1(19) - 2020 - str.72-78
6. Dyatlov V.Y. Elementy teoryy perenosa elek-trodnoho metalla pry elektroduhovoy svarke// novye problemy svarochnoy tekhnyky: sb.st. Kyev: Tekhnyka, 1964 S.167-182.
7.Paton B.E., Leskov H.Y. Tekhnolohyya elektry-cheskoy svarky metallov y splavov plavlenyem 1974 M.: Mashynostroenye
ХАРАКТЕРИСТИКА ОСУЩЕСТВЛЯЕМЫХ ГЕОЛОГО-ТЕХНИЧЕСКИХ МЕРОПРИЯТИЙ И РАССМОТРЕНИЕ ПОКАЗАТЕЛЕЙ ПРОЕКТНЫХ РЕШЕНИЙ ОБЪЕКТОВ РАЗРАБОТКИ НА
МЕСТОРОЖДЕНИИ
Куангалиев З.А.
Атырауский университет нефти и газа. Казахстан
Курсина М.М.
Атырауский университет нефти и газа. Казахстан
Дюсен Д.
Атырауский Филиал ТОО «КМГ ИНЖИНИРИНГ». Казахстан
Жакупов А. С. магистрант Шайхы Б.С.
магистрант
CHARACTERISTICS OF ONGOING GEOLOGICAL AND TECHNICAL MEASURES AND CONSIDERATION OF INDICATORS OF DESIGN SOLUTIONS FOR DEVELOPMENT OBJECTS IN
THE FIELD
Kuangaliev Z.
Atyrau University of oil and gas. Kazakhstan
Kursina M.
Atyrau University of oil and gas. Kazakhstan
Dyusen D.
Atyrau Branch of KMG ENGINEERING LLP. Kazakhstan
Zhakupov A. magistrant Shaikhy B.
magistrant
Аннотация
Статья направлена на получения промышленного притока нефти из интервала верхнеюрских отложений, месторождение разрабатывается на естественном режиме без поддержания пластового давления. Добыча нефти осуществляется фонтанным и механизированным способами. В четырех скважинах ведется совместная эксплуатация двух горизонтов. Отказ от бурения некоторых проектных скважин обусловлен сложным геологическим строением месторождения и его неполной изученностью. Определены характеристики энергетического состояния продуктивных залежей и контроля за разработкой в скважинах месторождения
Abstract
The article is aimed at obtaining an industrial inflow of oil from the upper Jurassic deposits, the field is developed in a natural mode without maintaining reservoir pressure. Oil production is carried out by fountain and mechanized methods. In the four wells conducted a joint operation of the two horizons. The refusal to drill some project wells is due to the complex geological structure of the field and its incomplete study. The characteristics of the energy state of productive deposits and control over development in the wells of the field are determined.
