CC BY
33
Сельское хозяйство
УДК. 631.563.8
MODEL OF DISTRIBUTING LIQUID PRESERVATIVES IN A VEGETABLE MASS I.M. Kurochkin1, Yu.Ye. Glaskov1, A.V. Milovanov1, N.L. Nikulshina2
Departments: «Mechanization of agricultural production» (1),
«Foreign Languages» (2), TSTU
Represented by a member of the Editorial Board Professor V.I. Konovalov
Key words: concentration; non-uniformity; preservative.
Abstract: The paper deals with the way of laying the feeds in by means of their ensilaging with the devised mobile unit being used. The principles of operation of this unit as well as the techniques for determining the depth of penetration and concentration of the preservatives in a silage mass are described. The advantages of application of the proposed unit are discussed.
One of the most important goals of feed production are to provide cattle breeding with high-grade feeds, to lay them in timely and qualitatively as well as to conserve their nutrients. These goals can be achieved by applying liquid preservatives while laying juicy vegetable feeds in. There are many ways of adding preservatives to the vegetable mass, which can be classified according to the type of the preservatives, the place of adding, the manner of adding, etc.
One of the perspective technologies of laying a silage in, with liquid preservatives being added to it, is that according to which the preservative is to be added to the vegetable mass directly when the mass is moved and tamped down in a trench by a tractor. In this case the amount of the preservatives being put in corresponds to the mass of the given portion. This technology is carried out by means of the unit the main elements of which are: feeders, pumps, pumps-feeders, injectors, etc.
The deficiencies of the present equipment are known to be insufficient uniformity of distributing the preservative in the unit of volume (portion) of feed, metal consumption, complexities arising when dose of the preservative is changed.
To solve this problem we have designed the unit which enables to improve the quality of feed being laid in Fig. 1 [2].
On the pendulous tractor frame there is gripping device 1 with injectors 2 connected through pressure pipeline 15 with pump 14 and container for preservatives 13. A feeder consists of adjusting hydraulic cylinder 7 and controlling hydraulic cylinder 11. The working inner area of the adjusting hydraulic cylinder 7 is connected with the inner area of the hydraulic cylinder 3 of the pendulous tractor frame. Piston 8 of the adjusting hydraulic cylinder 7 is spring-loaded by spring 6. There is stop 9 on the rod of piston 8. The controlling hydraulic cylinder 11 is designed in the form of a cylinder with two cavities separated from a central hole by a partition. One of the cavities of the controlling cylinder 11 is provided with piston 12 on the spring-loaded rod of which there is switch 10 of the electrical circuit which controls pump operation. This cavity is open to pressure pipeline 15 through valve 5. The other cavity of the
controlling hydraulic cylinder 11 communicates with tank for preservative 13 through a fitting pipe at the one end and with pressure pipeline 15 through another fitting pipe at the other end. The cavity is provided with elastic membrane 4 which locks the entrance from the pressure pipeline 15.
The equipment operates in the following way. Gripping device 1 (Fig. 1) takes a portion of vegetable mass introducing injectors 2 into it. With the help of hydraulic cylinder 3 the pendulous frame with gripping device 1 is raised. The hydraulic pressure in the working cavity of hydraulic cylinder 3 which corresponds to the mass of the vegetable feed portion is transferred into the working cavity of the adjusting hydraulic cylinder 7. Spring-loaded piston 8 moves until the efforts of the spring compression and hydraulic pressure are balanced. Meanwhile the rod of piston 8 with stop 9 comes out of contact with switch 10 making the electrical circuit of the pump drive be ready. By turning on an electrical switch located in the tractor cabin the electrical circuit controlling the operation of pump 14 is closed and feeding the preservative through pressure pipeline 15 and injectors 2 into vegetable mass starts. The preservative moving inside pressure pipeline 15 gets through valve 5 into the cavity of controlling hydraulic cylinder 11 and simultaneously affects membrane 4 which covers the hole between the two cavities of controlling hydraulic cylinder 11. Under the pressure of the preservative piston 12 goes up. Pushbutton switch 10 located on the spring-loaded piston rod 12 reaches stop 9 and breaks the electrical circuit controlling pump operation 14. Feeding the preservative is stopped. Pressure in pipeline 15 falls and membrane 4 opens the hole between the two cavities of hydraulic cylinder 11. The preservative residing in hydraulic cylinder 11 being affected by the spring of piston 12 and by chute flows down into the tank for preservative 13. Piston 12 returns to its lower dead point. After unloading the mass and resetting pressure in the working cavity of hydraulic cylinder 3 piston 8 of adjusting hydraulic cylinder 7 goes down until stop 9 comes into contact with switch 10.
One of the main functions of an injection device consisting of a number of tubular injectors is to provide uniform distribution of preservative solution in the feed mass.
The desired parameters will be the following: the interval of mounting injectors on the mobile frame, the diameter of holes and the interval of their placing on the injectors.
These parameters are affected by many factors, such as pressure provided by pump, physical-mechanical properties of injectors movement in the feed mass.
The critical points in determining design-mode parameters are the depth of
penetration of preservatives into the feed mass and the diameter of preservative spray cone.
Taking into consideration the above mentioned factors, the purpose of the research was to define the concentration of the preservative at different points of spray cone. The solution of the stated problem was realized in two stages:
1. Specification of the boundaries of preservative spreading of the supposed unit.
2. Determination of the ways of spreading liquid preservative and its concentration within the cone.
To study the distribution of liquid preservative in the bulk of vegetable feed a process of penetration of the preservative flow into the feed mass was modeled.
Axial velocity of outflow into the fluid of high density in comparison with the density of gas for axis symmetric flow is defined according to formula [3]
0,48v0
v = —-----^ , (1)
^ + 0,145
d
where vx - velocity in the cross-section being studied at the distance x from the mouth of a nozzle, m/s; x - distance from the nozzle mouth up to the point being studied, m; a
- coefficient of turbulence, characterizing the intensity of mixing of flow with fluid; v0
- velocity of outflow from the nozzle mouth, m/s; d - diameter of a nozzle mouth, m.
Changing a preservative mass in the elementary volume V per unit of time is defined by:
dm = p(vjds -V2 ds), (2)
where p - density of preservative, kg/m3; vu v2 - flow velocities at the entrance and exit accordingly; ds - an area of cross-section elementary volume dV, perpendicular to the velocity of spreading the flow.
Changing the concentration at the point being studied is defined according to formula
dc = dm/dV ■ dt. (3)
Taking in account that dV = dsdx, we get the dependence of the velocity of changing preservative concentration per elementary time
dc/dt = dm/dsdx. (4)
Considering (2) and (4) the expression will be the following
dc/dt = - pdv/dx. (5)
Taking the derivative of velocity (1) on coordinate x
, 0,48vo —
—=—(6)
dx i \
ax i ax '
— + 0,145
d
and having substituted the received value into formula (5), we get
dc 0,48v0 a
d> di —1+0,145 ^ 2
(7)
Integrating (7) on t, taking into consideration the initial conditions, we get volumetric concentration C [kg/m3] on torch axis as function of time and distance from a nozzle
c = a ' 2 t. (8)
d {d + 0,145
Expressing v0 through P and making some transformations, we get:
0,48m»/2Pp ■ at
c = ; p X2. (9)
d (d + 0,145
Suppose the lines of equal concentration of preservative be described by the conchoid Nikomed equation (3)
y2 = (r - x) x2A, (10)
where parameter A is defined by the angle of preservative spray close to injector
tga = lim y / x = limJ(r - x)x 2 A / x2 =4rA. (11)
x^0 x^0 ’
After having made the corresponding transformations parameter A is defined by the expression
A = tg2a/r. (12)
The volume of the entire torch (Fig. 4) into which the preservative penetrates under pressure is defined by formula
V =nj y 2 dx. (13)
After substitution of equation (13) in formula (10) and a number of transformations equation (13) will take the form
r
V =nj(r - x)x2Adx. (14)
0
Formula (14) having been integrated takes the form
V = n A r 4/12. (15)
To carry out further research the area of torch light was divided into n equal in
volume sections (Fig. 2), the boundaries of each section being defined by the equation:
= ^(xi-1 )4 +
12V
-¡AT- (16)
where Vn - volume of nth fraction of torch light Vn = V/n.
It is supposed accurately enough that concentration of preservative in volume Vn is equal to the concentration on torchlight axis at the distance xt from the nozzle mouth.
Since liquid part of silage is a solution of a weak base, then on adding weak acid the calculation of pH is performed according to formula [4]:
pH = lg(CsU/C ) + pHa, (17)
Fig.2 Scheme of spreading the preservative in the mass for weak acid pHa is defined
р Ha =- lg#^
where Ka - a constant of acid dissociation.
The main reaction for silage until processed is
pHsil = - ig(10 ~14Ц к silCsil)
(18)
(19)
where Ksil - an average constant of ion dissociation in silage; Csil - ion concentration in silage:
Csil = (10pHsll-14)2/Ks1i.
(20)
By substituting (20) into (17) the acidity of mass in a given area is defined by formula
(iopH -14)2
pH=-lg/^c+igv ;, (2i)
KsilC
where Ksil - generalized constant of dissociation of chemical substances in a vegetable mass.
Having substituted expression (9) into formula (21), we get
Ka0,48^72PP •at , (10PH’-14)
р H = - lg
- lg-
ax+0,14512 d
d ' 1 ax . _1 j
d + 0,145 I d
(22)
The coefficient of non-uniformity of preservative distribution in the volume of vegetable mass is defined by formula [5] :
K =
)/Z(PHi -PHav)V(«1 -1)
PHa
(23)
where nx - a number of tests; pHav - average acidity; pH,- - acidity in i t point.
On the basis of theoretical research we constructed a graph of changes in the non-uniformity of distributing liquid preservative (K) depending on the diameter of the hole (d).
From the dependence (Fig. 3) we can conclude that the diameter recommended for the device varies from
1 to 3 mm. Under such a diameter the non uniformity of distributing preservatives ranges from 8 to 9 %.
Theoretical calculations have been confirmed by the experimental research.
Fig. 3 Graph of changes in the non-uniformity of preservative distribution
Acknowledgements
The authors would like to thank N.L. Nikulshina for her help in translating the paper into the English language.
References
1. Fedoseev P.N., Gundorov V.V., Sokolov A.V. The use of chemicals in laying in of feeds. - M., 1988. - 172 p.
2. Patent № 2061387 of Russian Federation. - MKH A23K 3/03. - Unit for putting preservatives into vegetable mass.
3. Abramovich G.N. Theory of Turbulent Jets. - M., 1960. - 780 p.
4. Vasiliev V.P. Analytical Chemistry. - M., 1989. - V. 1. - 320 p.
МОДЕЛИРОВАНИЕ ПРОЦЕССА РАСПРОСТРАНЕНИЯ СТРУИ ЖИДКОГО КОНСЕРВАНТА В МАССЕ РАСТИТЕЛЬНОГО КОРМА
И.М. Курочкин1, Ю.Е. Глазков1, А.В. Милованов1, Н.Л. Никульшина2
Кафедры: «Механизация сельского хозяйства» (1),
«Иностранные языки» (2), ТГТУ
Ключевые слова: консервант; концентрация; неоднородность.
Аннотация: Изложен способ заготовки кормов путем их силосования с применением мобильного агрегата, а также описан принцип работы данного агрегата, приведена методика определения глубины проникновения и концентрации консервирующего препарата в объеме силосной массы. Описаны преимущества применения предложенного агрегата.
2
3
4
5
а. мм
Modellierung des Prozesses des Strahlvertriebes des flüssigen Konservierungsmittels in der Masse des Pflanzenfutters
Zusammenfassung: Es ist die Weise der Futtererfassung mittels ihrer Silierung mit der Anwendung des Mobilaggregates dargelegt. Es ist das Arbeitsprinzip des gegebenen Aggregates beschrieben. Es ist die Methodik der Bestimmung der Tiefe der Durchdringung und der Konzentration des Konservierungspräparates im Umfang der Silomasse angeführt. Es sind die Vorteile der Anwendung des angebotenen Aggregates beschrieben.
Modélage du processus de la répartition du jet du conservant liquide dans la masse du fourrage
Résumé: On propose le moyen de la conservation du fourrage par son ensilage à l’aide de l’agrégat mobile et l’on décrit le principe du fonctionnement de cet agrégat. On cite les méthodes de la définition de la profondeur du passage et de la concentration du produit conservant dans le volume de la masse de silo. On décrit les performances de l’application de l’agrégat proposé.
