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29
d2s ( ■
of the form S =-= F {t, s ,s). After solving equation of numerical
dt2 1
methods we obtain charts (Figure 3)
(Kv -Sf) ■ sin(2 -n-fafa)
d2
S = — = K
dt2 mp
Kv •(©• R)2
m
+ 2 • o- S + g • sin(o • t + 4>0)
—r - g • cos(o • t + 0J r
dX = _ (K *-Q-sin(. dt2 m
dt2 m
whereK — the coefficient of friction between the cotton and the
mp
drum pegs;
K — coefficient proportionality;
and ^ — the angle of the capture and dumping of cotton groves drum;
® — peg drum speed, s"1; m — cotton weight, kg; R — peg drum of radius, m;
d2 y dt2 ' d2 y dt2 '
(Kv-s;2)-cos(fa)
(Kv -SK2)-cos(2■ n-fa)
(3)
(4)
g — acceleration of gravity, m/s 2;
t — time s;
Conclusion
On the basis of the analysis of the research results it is found that, for effective work drum feeder, which provides its trapping ability of soft contaminants and uniform supply of cotton to the working chamber a given performance, one must reduce irregular rotation peg drum by optimizing the elastic-dissipative parameters transmission.
References:
1.
2.
Rakhmanov HK Development of a rationaltechnology distribution of raw cotton in its storage: Dis ...Cand. tech. Sciences - Tashkent, - 1996. - P. 107.
Dzhuraev A. Modeling the dynamics of machine units ginning machines - Tashkent: Fan, - 1984. - 128 p.
3. Juraev A. Dynamics working mechanisms of cotton processing machines. - Tashkent: Fan, - 1987. - 168 p.
4. Turanov H. T. Swing and loading of composite shafts drum some tyape of cotton machines - Tashkent: Fan, - 1982. - 165 p.
5. Rakhmonov H. K. Nagruzhennost screw shaft cotton supply distributor in their storage//Problems Textiles - Tashkent, - 2009. - № 1.
DOI: http://dx.doi.org/10.20534/ESR-17-1.2-230-232
Rakhmanov Hayridin Kodirovich, Doctor of Technical Sciences, Professor Bukhara technological engineering Institute, Uzbekistan
E-mail: raxmon@mail.ru Rajabov Ozod Isroilovich, Assistant of the Department of "Technologier and eduipment" Jomardova Dilafruz Qahramonovna, Assistant of the Department of "Technologier and eduipment"
Sayfullayev Sayyor,
Assistant of the Department of "Technologier and eduipment"
Muzrobov Suxrob,
Assistant of the Department of "Technologier and eduipment"
Investigation of methods of preparation of cotton and its components for storage
Abstract: This article discusses the regulation of the process of technical preparation of seeds to send oil mills. Regulations is applicable technical measures for the preservation of quality of seeds on the cotton oil mills. There is expressed the most important physical-mechanical properties of microhardness peel. The results of theoretical study on heat and mass transfer in order to analyze the possibility of an intensification of the uniformity of the heating and drying of raw cotton components.
Keywords: Cotton fibers, polyester, moisture, seeds, oil, drum dryer, peel, core, micro-hardness, heat treatment.
As everyone knows that cotton is the most useful products in the world. It is breathable, hypoallergenic, soft to touch, comfortable for body, rather warm, absorbs moisture, easily bleached, not electrified. Sometimes as an addition it is added an artificial fibers, such as polyester or lycra [1; 4].
Four species (Gossypium arboreum, Gossypium barbadense, Gossypium herbaceum, Gossypium hirsutum)of cotton began in-
dependently used for textile production. In general, since the be" ginning of the XX century took place in employment drop in the cotton industry due to the development of mechanization. Today, cotton remains as one of major export goods in many countries (Table 1) and a large part of the annual cotton harvest is long staple cotton [2].
Investigation of methods of preparation of cotton and its components for storage
Table 1. - Top 10 Cotton Producing Countries (in metric tonnes)
Rank Country 2010 2012 2014
1 China 5,970,000 6,281,000 6,532,000
2 India 5,683,000 6,071,000 6,423,000
3 United States 3,941,700 3,412,550 3,553,000
4 Pakistan 1,869,000 2,312,000 2,308,000
5 Brazil 973,449 1,673,337 1,524,103
6 Uzbekistan 1,136,120 983,400 849,000
7 Turkey 816,705 754,600 697,000
8 Australia 386,800 473,497 501,000
9 Turkmenistan 230,000 295,000 210,000
10 Mexico 225,000 195,000 198,000
Source: Statistical data of top cotton producers.
Including cotton in Uzbekistan is an export crop and one of the main strategic resources of the country and the main source of hard currency for the country. Uzbekistan is the sixth largest producer of cotton in the world and the fourth largest exporter of fiber, which is 5 percent of the world production of cotton fiber. Uzbekistan exports about one million tons of cotton fiber per year. In order to preserve the natural quality of the produced fiber it is necessary to comply with certain technical regulations and the conditions of storage, which is the main key.
Experience shows that a significant portion of the cotton produced in the ginning factories, has high humidity. In accordance with the process regulated cotton temporarily stored before being processed mainly at the sites. The fibers and seeds are subjected to additional moisture due to rainfall. Such seeds and fiber, respectively, require a change in processing conditions of storage and processing in oil and fat, and textile mills.
Excessive moisture content and trash cause disturbances in the process of their processing. It should be noted that the measures applied to preserve the natural qualities of technical seeds and fibers and cotton oil mills are ineffective. It is known that the raw cotton is subjected to humid drying DCR ginning factories to processing at its humidity was within 8-9%. However, in most cases, the seeds go high humidity, because the residence time of raw cotton is limited to a drying drum and the seeds are dried because they are not uniform in their structure and are composed of three main components: fiber, peel and seed core. The chemical composition of the components is different and therefore different humidity their
Figure 1. Temperature dependence of (a) and
properties. With the change in the humidity of cotton seeds and change its physical and mechanical properties which depend on the process of processing the material and properties of the resulting products [3].
Importance and the physic- mechanical characteristics iscon-sidered hardness of peel. During processing under the influence of mechanical stress seed peel is damaged seed, thereby forming a skin with a fiber and broken seed. The degree of damage depends more on the strength of the peel of seeds, which in turn is interconnected with its humidity. Therefore, to determine the influence of these factors on seed quality parameters studied in laboratory species in cotton seeds and S-6524, and Bukhgara-6 and humidity 7-15%. When humidity is 7.8% microhardness of seeds for breeding.C-6524 and Bukhara-6 were respectively is 205.8 and 191.7 N/mm2. With an increase of seed moisture content to 12% microhardness decreased to 132.5 and 128.2 N/mm2. At that time, with the growth, humidity of 12% to 15% microhardness decreased by only 14 N/mm2. The weakest section of the seed capable of destruction and the formation of defects is oval part. Therefore, the processing of seeds with moisture content below 7.0% broken seed increases above 9.0% increases skin with fiber. It was assumed that by controlling the temperature conditions can not create favorable conditions that will reduce the extent of the damage and provide a uniform and intensive removal of moisture from the surface of the cotton component. To determine the temperature and moisture on the surface along which heat transfer occurs in contact with other surfaces, contact unsteady equations were used heat-change satisfying conditions and selection of heat absorption of moisture when passing through these surfaces. Assuming that is outer and inner surface temperature as well as humidity and the same, it is possible to write the following equation [4].
T = TJt) = T + (T - T )Q(t), u2 = uH - (uH - uk)W(t). (1)
Moisture on the surface of the skin and core seeds are calculated according to the formulas
U20 = u1(rl,t) = uh - (uA - uk )W (t) , (2)
U0 = Uh - (uh - Uk )PnX(T) ,
T0 — Initial values of temperature and moisture-or some components (eg, air) of raw cotton.
p, Pj — the density of the skin, the air layer and the core c ci — peel and core the heat capacity Tk, T and T — respectively given skin temperature, air gap and seed kernel
W
humidity (b) 1 - fibers, 2 - peel, cores 3 times
According to the results of numerical and experimental studies obtained of temperature and humidity of the cotton fiber, peel and seed core of (Fig.1) time. They show that the temperature differential between the fibers and the peel and seed kernel after 30 seconds is 47 0C and 59 0C, a moisture gradient in this case is 1.6% and 9.6%.
These results suggest reviewing the application of the high temperature for drying cotton and difficulties to ensure uniformity deletion of moisture from the cotton component
Further studies have shown that the storage of moist seed is higher than 10% without preventive measures, leading them to self-warming. The intensity of this process depends on the humidity and ambient temperature. Thus, the humidity in the seeds starts self-warming 12-15% on the third day, above 20% — in the second.
When stored cotton seeds with a moisture content of 14.7% of its oil content has changed — the data on the first day I grade 22.4% after 7 days, in 21.6% at 21 days and 18.2% in 35 hours 17.3%.
Increased humidity and weed seed technology led to the creation of favorable conditions for the development of fungus end biological processes, which leads to a qualitative change and reducing their oil content.
To prevent these processes proposed treatment of cotton
seeds in various ways: chemical, thermal, biochemical, electrical, etc. Each of the methods has its own characteristics, advantages and disadvantages. However, given storage cotton seed process is difficult to apply in industry.
One of the main ways to prevent the process of destruction of cotton seeds is heat treatment using heat and mass transfer and hydrodynamic processes. This method can be used in the processing of cotton seeds before storage or an intensification of technological processes of its processing.
Analysis of the known conditions and methods for the preparation of cotton seeds to the processing and storage has shown that it is possible to prevent the self-warming, and change their natural properties.
The basis of the study of self-warming process is settled down not only humidity factor of cotton seeds, but also biochemical and biological processes, which are recorded by changing the speed of germination and seed oil.
Сonclusion: Based on the above analysis and research to develop and offer new ways of preparing cotton seeds for storage using the heat and mass transfer, hydrodynamic processes are new technologies.
References:
1. Rakhmanov KH. K. "Development of effective structures and methods of preparation of the system of calculation, loading and storage of cotton in the module",: Dis ...Doc. The. n. Sciences. - Tashkent, - 2012.
2. Statistical data of top cotton producers.
3. Rakhmanov H. K. The theoretical study of stress-strain state of free-bulk raw cotton layer to a limited extent. "Mechanical problems". Uzbekistan journal. - 2005. - 46 p.
4. Rakhmanov KH. K. Primary treatment of textile raw materials textbooks. - Bukhara: - Mullif - 2014.
DOI: http://dx.doi.org/10.20534/ESR-17-1.2-232-235
Rakhmatov Orifzhon, Gulistan State University (Republic of Uzbekistan), PhD of technical sciences, Assoc. Prof, chair Technology processing of agricultural production E-mail: ax-stajyor@mail.ru
Optimization of chamber tunnel typed thermal solar fuel — drying installation with oscillating mode
Abstract: A two-chamber convective typed drying installation with two forms of energy supply — electricity and solar radiation are developed. As the test results showed, heat savings in the process of drying the agricultural products based on proposed diagram amounted 27-28%.
Keywords: installation, solar radiation, agricultural products, drying, drying medium, chamber, oscillations, heat, convections, optimization.
Introduction. Processing of agricultural products requires a certain power expenditures. Drying of the following highly humid and sugar containing products are considered as the most energy-consuming drying process that made from: Grapes, melons, figs, pears, apples, etc. In effort to produce 1 kg of a dried product there should be removed a moisture in amount from 4.2 to 8.5 kg, based on calculation when it is calculated referring to heat this may range from 10,000 to 21,500 kJ. Performance coefficient of many drying assemblies used in the vegetable — drying industry, does not exceed 55% [1, 15-20].
This data shows the acute necessity in improving the energy efficiency of drying assemblies by using of the best achievements of the state-of-the-art technology and processing methods, the possi-
bility of heat recovery exhausted drying medium and optimization of drying modes (conditions).
The modern theory of optimal process control allows you to select several criteria to optimizing drying proceedings, but at the same time it should be noted that the optimization of operating modes of the drying installation for a particular type ofproduct margins its use in drying other types ofvegetable raw materials. Therefore, it is necessary the transition from optimization to the efficient and operating conditions, expanding the range and sphere of these drying assemblies.
Increasing the energy efficiency of dryers may be obtained by means of effective using the processed heat transfer having a large enthalpy that conditions the feasibility of its usage as a secondary energy source.
