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1s
d ) https://dx.doi.org/10.36522/2181-9637-2023-6-4 UDC: 677.051.164.6:67.05(045)(575.1)
OPTIMAL DISTRIBUTION OF THE PROCESSED WOOL MASS IN SQUEEZING ROLLERS TO ENSURE BETTER PROCESS EFFICIENCY
Tuguzbaeva Robiya Berdimuratovna,
Assistant, e-mail: trobiya89@mail.ru;
Khakimov Sherkul Shergazievich,
Doctor of Technical Sciences, Professor, ORCID: 0000-0002-1933-1948, e-mail: lionandlion9@mail.ru
Tashkent Institute of Textile and Light Industry
Introduction
The device for squeezing of wool in a wool-washing barge relates to primary its processing and will be used in wool-washing barges for squeezing the wool from the washing solution.
Squeezing rollers installed after each washing bark are designed to remove washing solution from the wool when moving to the next bark. The squeezing rollers help wash the wool, since contaminants are removed from the wool along with the squeezed washing solution.
The main disadvantage of existing squeezing rolls is their low squeezing efficiency, which leads to the need for repeated sequential washing of the material in several docked sections of the barge. Poor spinning capacity of repeated washing still does not achieve required cleanliness of the wool.
Insufficient squeezing efficiency is caused by limited pressure force of the upper roller, which can be raised, as well as by pressing of the squeezing shaft on the firmly fixed lower squeezing shaft. Moreover, the low spin efficiency can be explained by the fact that spinning runs only in the spot of the smallest gap between the shafts, that is, in a limited space (Bakhadirov, 2010).
Abstract. The article discusses a squeezing device in a wool washing machine that helps resist low squeezing efficiency, providing high-quality washing. The analysis presents roller mechanisms, which ensure a higher level of wool purity and an optimal squeezing process. Findings, presented graphically, show the distribution of the mass of processed wool as it passes through a pair of shafts. The geometry of the layer of wool compressed in testing affects the movement of a liquid within it, the distribution of pressure across the width of the layer, the conditions of capture, and its movement within the rollers. A water-saving washing machine, comprising a washing barge, a running rake, an unloader, an output conveyor, and electric motors, has been experimentally designed. The article discusses the issue of washing the wool. The process of collecting wool from a liquid medium and unloading it for the next stage of washing was subject to analysis. The review of findings from experimental tests showed that the suggested barge washing machine leaves fewer impurities and less fat compared to the existing washing unit.
Keywords: wool, bark, scuffing, primary processing, wool washing unit, impurities, fat, squeezing mechanism. catcher-unloader, cleaning solution, rake, sickle-shaped arms.
ИШЛОВ БЕРИЛАЁТГАН ЖУН МАССАСИНИНГ
ВАЛЛИ СИКУВЧИ МОСЛАМАДА ТАКСИМЛАНИШИНИ МУКОБИЛЛАШТИРИШ ХИСОБИГА СИКИШ САМАРАДОРЛИГИНИ ОШИРИШ
Тугузбаева Робия Бердимуратовна,
ассистент;
Хакимов Шеркул Шергазиевич,
техника фанлари доктори, профессор
Тошкент ту^имачилик ва енгил саноат институти
Аннотация. Мацолада жун ювиш цозонида сифатли ювиш ва юцори сициш самарадорлигини таъминлайдиган сицувчи мослама куриб чицилган. Тахлиллар шуни курсатдики, валли механизмлар ёрдамида жун тозалигининг юцори фоизига эришилади, шунингдек, сициш жараёни муцобиллашади. График шаклда ишлов берилаётган жун массасининг бир жуфт валлардан утаётгандаги тацсимланиши курсатилган. Тадцицот натижасида жун сицилган цатламининг геометрияси, унинг суюцликдаги харакати, цатламнинг кенглиги буйлаб босимнинг тацсимланиши, тутилиш шартлари ва унинг валлардаги харакатига таъсир цилиши аницланди. Ювиш цозонлари, харакатланувчи паншахалар, тушириш механизми, чицарувчи транспортер ва электродвигателлардан ибо-рат сувни тежайдиган экспериментал ювиш машинаси яратилди. Мацолада жунни ювиш муаммоси мухокама цилинган. Суюцликдан жунни олиш ва кейинги ювиш цозонига тушириш буйича тахлил утказилди. Тавсия этилган машинада ювилган жун таркибидаги ифлос аралашмалар ва ёглар мавжуд ювиш машинасида ювилган жунга нисбатан камайиши тадциц этилди.
Калит сузлар: жун, ювиш цозони, дастлабки ишлов бериш, жун ювиш агрегати, ифлос аралашмалар, ёг, сициш механизми, олувчи-туширувчи, ювиш суюцлиги, паншаха.
ОПТИМИЗАЦИЯ РАСПРЕДЕЛЕНИЯ МАССЫ ОБРАБАТЫВАЕМОЙ ШЕРСТИ В ОТЖИМНЫХ ВАЛКОВЫХ УСТРОЙСТВАХ ДЛЯ ПОВЫШЕНИЯ ЭФФЕКТИВНОСТИ ПРОЦЕССА
Тугузбаева Робия Бердимуратовна,
ассистент;
Хакимов Шеркул Шергазиевич,
доктор технических наук, профессор
Ташкентский институт текстильной и лёгкой промышленности
Аннотация. В статье рассмотрено устройство, обеспечивающее качественную мойку и высокую эффективность отжима в баке для мойки шерсти. Проанализирована работа валковых механизмов, при помощи которых осуществляется высокий процент очистки шерсти и оптимизация процесса
Roller mechanisms have become widespread owing to their simple design, continuous technological process of wool treatment , and combination of several functions. The variety of operations performed by roller mechanisms has not yet made it possible to develop a unified system for their design, which is explained by different technological tasks and phenomena taking place in the contact zone of the shafts. Since the existing classification does not consider a functional purpose of the roller mechanisms and related phenomena in the contact area, it has become relevant to investigate and systematize their interaction with processed wool.
Each point on the surface of the processed wool, at a given point at a time, corresponds to the speed of its movement and contact stresses, determined in the magnitude and direction, which together form a vector field. Creation of stress and velocity fields on the contact surface of the shafts with a given nominal value and permissible deviation, is considered as a required prerequisite for the mechanism to perform a certain function.
For compression mechanisms, the main is the normal stress field, and the intensity of the impact is determined by duration of the load and a maximum stress on the contact caused by compression of the shafts (Gorbunova, et al., 1981).
For many mechanisms, these conditions are considered as sufficient. The main objective of designing the roller mechanisms is to ensure the above listed prerequisites, which require to know the fields and their influence on the mechanism's performance of specified functions, as well as the characteristics of the fields that most influence the function performed. When combining several functional purposes of a mechanism, the fields have to meet the requirements of each function (Khakimov & Tuguzbaeva, 2021) at a time.
Materials and methods
Since the magnitude of stresses and speeds at different times at different points of
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contact vary, to fully characterize the fields, in addition to the nominal value, it is becoming important to know deviations of speeds and stresses that disrupt the technological procedure of wool treatment thus reducing the quality of the products. In compressive roller mechanisms (squeezing, deforming), the normal stress field is realized through deformation of processed wool.
It is a transverse deformation of the processed wool that determines moisture removal in roller devices:
AW = k • AH
Where, AW - the amount of moisture removed;
k - coefficient of proportionality, depending on the surface density of the wool;
AH - transverse deformation of the wool layer
Experimental studies (Uz Patent No. FAP56406, 2022) of the dependence of deformations of the treated layer and the effect of moisture removal from it on the magnitude of the load in compressive roller mechanisms can be represented by generalized graphs in fig: 1 a, b.
In longitudinal-traction mechanisms, when the growth of deformation of the wool layer under the influence of load stops, the tangential stresses, which determine the traction force, continue to grow. As a result,
отжима. Она представлена в графическом виде, демонстрирующем распределение массы обрабатываемой шерсти при прохождении её через пару валов. В процессе испытания установлено, что геометрия сжимаемого слоя шерсти влияет на характер движения в нём жидкости, распределение давления по ширине слоя, условия захвата и движение её в валах. Создана водосберегающая экспериментальная моечная машина, состоящая из бака для мойки, прогонных граблей, выгружателя, выводящего транспортёра и электродвигателей. В статье рассматривается проблема промывки шерсти. Проведено исследование процесса улавливания шерсти из жидкой среды и выгрузки её на следующий этап промывки. При испытаниях было определено, что в предлагаемой машине по сравнению с существующими наблюдается уменьшение сорных примесей и жира.
Ключевые слова: шерсть, бак для мойки, трепание, первичная обработка, шерсте-моечный агрегат, сорные примеси, жир, отжимной механизм, уловитель-выгружатель, моющий раствор, грабли.
the relationship between the load in the roller mechanism and the traction force (Fig. 1, c) is linear.
The stress state on the contact surfaces of the shafts can be determined by the magnitude of the load Q on the side of the clamping device, the intensity of its distribution q along the length of the shafts, the average np or the maximum n stress on the contact (Uz Patent
max ^
No. FAP56406, 2022).
ЛИ
AW
a Q 6 Q e Q
Fig. 1. Dependence of parameters, AW and F on the load on the mechanism shafts
The relationship between these quantities can be characterized by graphs (Fig. 2). Calculation of the effect of the roller
mechanism for any of these functions can differ only in the exponent that determines steepness of the curves.
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Fig. 2. Dependence of parameters q, n and
n on load
max
An interesting characteristic of the treatment process in a roller device is a distribution of the mass of processed wool as it passes through a pair of shafts. It resembles geometric shapes of the wool processed in the shafts. When processing the wool, the mass per unit area is called floor density, loading density or specific loading. Mathematically, this value can be represented as follows:
dM
m = — = j(x,y)
Where, dM - is the mass of fibrous wool located on the area dS;
x,y - coordinates of the point at which the specific load is determined.
The thickness of the wool layer at any point on the shafts is equal to:
m 1 .
8 = — a S = —j(x, v) Q <3
Here Q is the density of the fibrous material in the layer under consideration.
Different shapes of the wool layer can be described by different coordinate functions (let us assume that the X axis coincides with the direction of movement of the wool, the Y axis is parallel to the axes of the shafts). A continuous fibrous layer is described by a continuous function, a discrete layer and a layer with sharp changes in thickness are described by a discontinuous one.
The geometry of the compressible layer of wool affects the nature of movement of the liquid in it, the distribution of pressure across the width of the layer, the conditions of capture and its movement in the shafts.
When rolling one of the shafts of the pair against the other, resistance arises, which is taken into account by introducing a moment of rolling friction, that has a direction opposite to the other of the angular velocity. The rolling resistance depends on curvature of contacting surfaces, magnitude of the pressing force, mechanical properties of materials of contacting shafts and wool loading density (Khakimov, Tuguzbaeva, & Ismoilov, 2022), (Khakimov & Tuguzbaeva).
In the contact area of the shafts, local deformation occurs, making a contact area of a certain width.
For materials with properties of elasticity, viscosity and plasticity, the pattern of stress distribution in dynamics differs from the static one in that it is asymmetrical relative to the line of the centers of the shafts and is shifted towards the entrance of the material into their tip
The resultant of normal stresses is shifted in the same direction by an amount called the 'rolling friction coefficient'. This value determines the moment of resistance to rolling to a greater extent when processing fibrous materials. Energy consumption for the rolling process is also determined by tangential elasticity of the body materials, sliding on contact surfaces, adhesion phenomena, etc.
The process of rolling of one shaft on another can be compared with rolling of a wheel on a plane, which is featured by five possible types of loading from the action of active force factors (M - driving and braking moments, P - force applied to the shaft axis, 7 - load on the shaft from the clamping mechanism) (Tuguzbaeva & Khakimov, 2015).
In processing of a layer of wool on the module shafts, the intensity of the workload q is determined from the following relation
Q
q = b
where Q - the total load in a pair of shafts;
b - working length of the shaft.
The forces of interaction between the shafts and the processed material on their
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s
contact surfaces are the resultant from contact stresses - normal and tangential. With absolutely rigid shafts and a uniform distribution of the mass of a processed material in the direction of their axial line, the stress state will be identical along the entire length of the shafts, and the load intensity will be constant q = const.
This phenomenon is seen under the condition of using shafts of increased rigidity and when processing a layer of a uniform thickness. In reality, the shafts always bend, which leads to an uneven distribution of the load intensity along the axis of the shaft, even when processing a material that is absolutely uniform in thickness (for example, thin fabric in a straightened state). If the layer of the processed material is uneven in thickness, the intensity of the load will be distributed along the generatrix of the shaft according to a law that copies the distribution of the mass of the material in the layer q= const.
The main task of the force analysis of roller squeezing devices is to determine forces that act on their links in the operating mode. The force analysis enables retrieving information required for opting the parameters of parts, calculating their strength and rigidity, determining friction losses and the power required for the operation of the mechanism (Tuguzbaeva & Khakimov, 2021). Typically, force analysis is carried out using kinetostatic methods that is, taking into account the inertial forces applied to the links of the mechanism. However, due to the stationary operation of roller mechanisms and the good balance of their links, in most cases it is advisable to use only static methods for this purpose (Tuguzbaeva, Khakimov, & Akhmedova, 2022).
Two main combinations of kinematic connections of moving links are possible: a) both shafts of the pair are drive, that is, connected by a rigid kinematic connection with the drive; the processed material is set in motion by frictional forces on the surfaces contacting with the shafts; b) one shaft of the pair (drive), the material being processed,
and the second shaft (non-drive) receive movement due to friction forces on the contact surfaces;
Operation of the squeezing machines in practice has shown that the result of wool dehydration depends on the following factors: intensity of the distributed load in the tip of the module, diameters of the squeezing rollers, hardness and thickness of the elastic coating, which determine the width of the contact area of the shafts, conditions for removing the squeezed liquid from the tip, its temperature and viscosity, processing speed, type and properties of the canvas, finishing condition.
Research findings
The technological process of the primary treatment of wool is expected to ensure preservation of all valuable natural properties of the material. Deviations from the technological process or its incorrect choice lead to undesirable changes in the properties of wool as well as to losses of wool fiber both in primary wool processing factories and during further works at wool processing enterprises.
The bulk of contaminants are removed during the washing process, carried out on a wool washing machine, which represents the main part of the wool washing unit (Khakimov & Tuguzbaeva, 2021).
On all wool washing machines, when replacing contaminated solutions, the most contaminated solutions of the first and second barges are discharged into the sewer. Solutions of the third and fourth tanks, which are not too contaminated and contain unused detergents, are pumped into the first and second tanks. To do this, all the barges are connected to each other by pipes and are equipped with a steam jet pump.
The analysis of the design of existing wool washing units showed that these machines have very high level of water consumption and overall dimensions are chosen with high productivity.
Establishing of wool processing enterprises in the regions requires operation of small-sized and water-saving wool washing units. To carry out
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these tasks, a scientific and educational base has been created on the basis of the Department of Technological Machines and Apparatuses, engaged in the wool washing unit development process.
An experimental water-saving washing machine comprising a washing barge 1; running rakes 2, 3, 4; unloader 5; output conveyor 6; electric motors 7, has been designed.
Fig. 3. Experimental wool washing machine
Comparative experimental studies were carried out in view to investigate technological and design parameters of the proposed washing machine. The review shows that the proposed barge washing machine, compared with the existing one, retains fewer impurities and less fat. The productivity reached 100 kg/hour. The amount of water consumed by the proposed machine made 1.2 m3 per barge. Provided that processing lines are equipped with such wool washing units, washing of wool in remote areas will be possible using less water resources.
Further deep processing will be carried out in regional centers, which will enable opening new job places.
As a result of washing, fatty substances and other impurities are removed from the fibrous material.
Washing of wool and fibrous waste is implemented by means of washing machines and units, the main part of which are wool-washing barges, equipped with a drum for immersing wool in the washing solution, double rakes for moving wool and a mechanism for unloading wool from the barge.
To capture fibrous sticky materials from a liquid medium, for example, wool from
wastewater, consisting of a welded grate, from which the wool is removed by hand, periodically (Khakimov & Ismoyilov, 2019).
Review of the research findings
Some machines for washing the wool use a belt-type catcher, consisting of a welded frame, a conveyor belt formed with two rubberized belts, fastened together by transverse metal strips that go around the driving and driven drums. A nylon mesh is attached to the conveyor belt, which traps wool fibers and other contaminants.
Unloading of the collected wool from the mesh cloth is carried out using rubber cavities, which throw the fibers from the mesh onto the discharge conveyor. A catcher is also known as a piece, the movable mesh sheet of which is replaced by a stationary perforated sheet. To unload the collected fiber, a scraper conveyor made of two endless chains mounted on drive sprockets, is used. Rubber strips are attached to the chains on transverse metal bars, acting as scrapers that throw the fiber onto the discharge conveyor (Tuguzbaeva & Khakimov, 2022).
Currently, many wool washing machines use a catcher-unloader, having three combs, freely lying in the bearings of two triads. Crescent-shaped levers are being firmly fixed to the
S
comb axes. The triads, in turn, are mounted on a shaft to which rotational motion is imparted. The combs have slightly curved teeth for better fiber grip and retention (Fig. 4). When the combs move, the crescent-shaped arms rest against the roller, roll along it and take a stable position required for capturing the fiber from the solution and placing it on the discharge conveyor. This device is mainly used in wool-washing barges (Khakimov & Tuguzbaeva).
1 - comb, 2 - triple, 3 - lever, 4 - wheel. Fig. 4. Catcher-unloader
The main disadvantage of the above types of devices and the methods in which they are implemented is that fiber collection reaches only 60-70 %. Moreover, their components have low level of reliability (Khakimov, Tuguzbaeva, & Ismoilov, 2022).
After the unloader, the percentage of wool squeezing to remove washing liquid is not high. Therefore, the passage of liquid from one bath to another does not ensure effective washing of wool.
Conclusions
Based on the analysis, the following can be noted:
Labor-intensive replacement of drive elements, which often fail due to contact with aggressive environments, leads to downtime, use of additional material and extra costs (Khakimov & Tuguzbaeva, 2021).
Elimination of these shortcomings, i.e. increasing the efficiency of collecting and unloading fiber from the washing medium, reliability of the device and improving the working conditions of operating personnel is regarded as a sought-after task of the scientific research.
REFERENCES
1. Bakhadirov, G. (2010). Mechanics of the squeezing roller pair. (Uzbekistan). Tashkent: Fan.
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5. Khakimov, S., & Tuguzbaeva, R. (2021). Preparation of raw wool in Uzbekistan. Journal of Technical Research, 4(1).
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10. Tuguzbaeva, R., & Khakimov, S. (2021). Study of unloading wool from a washing liquid medium. Proceedings of the Conference "Innovative potential for the development of society: The view of young scientists", (pp. 314-316).
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Reviewer: Olimov A., Candidate of Technical Sciences, Docent of the Department "Natural Fibers and Fabric Processing", Jizzakh Polytechnic institute.
