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The results of testing of perforating metal trusses units to many times repeated loading
Fig. 4. Dependences of change of diameter division drum from a variation of factor of a friction of fibres about a tooth drum,
where: 1 - w = 750 s_1; 2 - w = 650 s-1; 3 - w = 550 s
On fig. 4 laws increases division drum from a variation of factor of a friction between fibres and before are presented diameter a side of teeth's drum which have linear laws.
The factor of a friction of fibres about a tooth surface division drum depends basically on properties of a fibre, its humidity, contact, weight of fibres on a surface of a forward side of a tooth and angular speed taking into account values of its fluctuations.
With the account of the above-stated the factor of a friction of fibres about a forward surface ofa tooth division drum changes in limits 0.25.. .0.35. Increase of force of a friction of fibres about a forward surface of a tooth барабанчика positively influences process of capture and extraction of fibres of a submitted tape process of digitization of fibres is intensified. From schedules it is visible, that with increase in
factor of a friction from 0.27 to 0.33 diameter drum increases from 6.48-10-2 m. to 8.2640-2 m. at a = 750s, and at c = 550s-, diameter drum increases from 4.41T0-2 m. to 6.2440-2 m. This results from the fact that, the more weight of fibres angular speed and size of its fluctuations, the is more than pressure ofa fibre upon a forward surface of a tooth of a drum and the more force of a friction. For maintenance of the demanded diameter division drum in repartitions (6.5...7.5)T0-2 m. for maintenance of linear speed of movement of fibres in repartitions 9.27.4.5 km/s the friction factor should be 0.26.0.32.
Conclusion
Use new division drum with an elastic element and recommended parametres improves process of spinning and quality of a received yarn.
1. 2.
3.
4.
5.
References:
Roglen V., Boushek A., etc. Without spinning. - M.: Easy and food are industrial, 1981.
Pavlov J. V. and others. The theory of processes, technology and the equipment of spinning of a clap and chemical fibres. - Ivanov, 2000. Djuraev A. Dj., Zhumanijyazov K. Z., DJumabaev G. Division drum the pneumomechanical spinning car. A floor. On delivery of patent Rep. Uzb. № 4814 from 07.04.2016 under the demand № FAP 20150001.
Djuraev A. Dj., Zhumanijyazov K. Z., DJumabaev G. Novaja an effective design division drum the pneumomechanical spinning car. Materials PHnK Actual problems innovation technologies in the conditions of integration of a science, formation and manufacture. -Tashkent. - Volume 2. -P. 177-179.
Yuldashev J. Improvement of quality of a pneumomechanical yarn with use it is a lot of calling sets. Diss. A Cand. Tech. Sci. -Tashkent, 2011.
Mamajanov Rustam Rahimjanovich, Director of Development and Science, Institute of Joint-stock «Uztyajpromproekt» E-mail: r_mamajanov@mail.ru
The results of testing of perforating metal trusses units to many times repeated loading
Abstract: The article presents the results of the test pieces of flat knots perforating metal truss railway bridges with differenced connected elements. As a result, the dependences for determining the carrying capacity of elements perforating farms and their residual life, taking into account available manufacturing defects.
Keywords: truss, components, test pieces, shear deformation, re-loading.
Many years of experience in the construction and operation the geometric dimensions of the elements, unacceptable gaps (dif-of metal bridges with perforating farms shows that in the process ferences) in the connecting member, what raises the need for on of manufacture, transportation and installation of superstructures impact assessment studies of deviations to the operational reliability may occur deviations from the project — discrepancy between of superstructures.
Section 10. Technical sciences
In [1; 2] shows the results of testing of experimental nodes fragments perforating metal truss railway bridges under static loading, and set the quantitative effect of the initial defects of manufacturing and installation work on node connections. The study of such joints of trusses is of great practical value under many times repeated loading.
Flat fragments with differences connected elements up to 4.5 mm. in the laboratory of the company "NIPPONSTEEL" were tested.Totally was manufactured 6 samples with differences of connected elements — 0, 3 and 4 mm.
Tests were carried out by employees ofthe company Saubaku Nippon Steel Engineering Co. Ltd and Joint-stock "O'zog'irsanoatloyiha".
2,0
The author participated in the processing of the experimental results and the preparation of opinions.
Measurements of shear strain during loading were recorded without stopping the pulsating load Electrical load cells. The detailed methodology of measurement of deformations is given in [1].
Options of repeatedly re-loading fragments were chosen by close to the actual operating conditions. The maximum value of the stress of tensile stress omax wereassumed about at 0.8...0.9 of the voltage corresponding to the beginning of an overall shift, and the minimum value was equal to omin within 0.3.0.4 of this voltage. The frequency of the application cycle — 800 repeated loadings per minute. The minimum number of loading cycles — 2 • 106 cycles.
1.5
I
1.0
0.5
à
k;* ►bit k / i • i
t * ► ^xj >
tor^^ c -- 1 \ ^ ) ^___ Ï
0,23
0.5
N/N.
0,75
1.0
O - Connection of elements without drop; A - Connection element with a difference of 3.0 mm; • - Connection element with a difference of 4.0 mm;
Fig. 1. The dependence of the shear deformations increase with repeated loading
On the fig. 1 were listed results of tests of experimental pieces.
As can be seen from the Figure the increase in the differential growth of connected elements increases the shear deformations. The fragments without fluctuations in the compounds after Ntxp = 2 • 106 load cycles accumulation of shear deformation was about 0.6 times from the level of the beginning of a general shift, ie connection works in the elastic region. When differential elements are 4.0 mm of accumulation of strain out of the elastic region and moved into the plastic zone.
Over the limit shift A accepted starting point of a general shift Ar , established based on the results of static tests [3; 4].
These changes depending on shear deformations under repeated loading multiple-fitted by the least squares method:
/ \ N
A = A
a + b-
N
(1)
ixp J
where, a = 0.2; b = 0.4 + 5/3.5;
5 — the magnitude of fluctuations in the connected elements, mm.
Proposed dependence satisfactorily describes the experimental results, the correlation coefficient calculated in the usual manner (the mathematical statistics) is in the range p = 0.72. The reliability coefficient of correlation to check the condition of the normal distribution of the random variables:
A = A
a + b
N N
(1)
exp J
I p\_ 0.72
a„ 0.196
p
= 3.67.
When the probability of P = 0.95 value t = 1.96 [5], as -P— = 3.67 > t = 1.96, the resulting dependence is significant.
The resulting dependence of growth shifts of connected elements in the joints nodes through metal trusses in the process many times — reloading can be used in the future to assess the carrying capacity of elements of farms and their residual life, taking into account these changes.
Installation of the IR dryer of raw cotton
References:
1. Mamajanov R. R. Testing of field nodes metal trusses//Problems of Mechanics. - 2012. - № 2. - P. 66-69.
2. Mamajanov R. R. The results of the test superstructures through farms//Herald of TARI. - 2012. - № 1-2. - P. 89-95.
3. Vaynblat B. M. High-strength bolts in the construction ofbridges. - M.: Transport, 1971. - 166 p.
4. Klyukin A. J., Sheikin A. A. Experimental validation of the mathematical models of friction connections. Scientific Bulletin ofVoronej State Architecture and Construction University//Construction and architecture. - 2010. - № 3. - S. 93-98.
5. Lujin O. V. Probabilistic methods of analysis of structures. - M.: Stroyizdat, 1983. - 94 p.
Rakhmatov Gulomjon Rahmonberdievich, Ferghana State University, senior researcher E-mail: gulomjon.rahmatov@mail.ru
Installation of the IR dryer of raw cotton
Abstract: The research offers the method of drying of raw cotton with pulsed IR radiation. Pulsed IR radiation is produced by functional ceramics of special preparation. Developed installation differentiates with energy savings and doesn't demand expenditure of hydrocarbon fuels.
Keywords: raw cotton, IR dryer, functional ceramics, radiant.
The process of drying wet materials is not only thermal, but also the process. Technical and energy parameters of the existing technologies of drying of agricultural products remains at the level of the 70s and the achievements to date using energy-intensive and expensive equipment.
In the present report indicated prospects of IR pulses in systems for drying agricultural products distinguished by their high operational parameters, low production costs and material consumption.
In recent years, it managed to develop a technology for functional ceramics, transforming primary energy pulsed infrared (IR) radiation and their widespread use in various fields of national economy [1, 472].
All materials were dried divided into three types: a capillary porous body, the body and colloidal colloidal capillary porous body. It is considered that the best effect in the drying process can be achieved in cases where the maximum light minimally absorbed by water and the base material. If we speak of thin layers of the objects, all substantially reduced to ensure that they do not overheat and retain their basic properties, it is also desirable to reduce power consumption and time [2, 69-73]. Not least take ease of use and reliability of the devices. In thin layers ofpoorly problem manifests solvent diffusion from the interior of the product to be dried. When it comes to thick layers, this problem comes in the first place, since she is the slowest step of the drying process and the total rate will be determined by it. The vacuum drying, vacuum it helps to speed up this step. But they are complex structures and high costs, as well as the practical difficulties of operating such systems.
The easiest solution to the problem — is to use pulses of high density at a low average power. Assume that the depth ofpenetration of the power P IR is for example 2 mm. If we will provide a pulse of radiation density 100 times greater, in order to obtain the same energy density within the product at the same extinction coefficient (specific penetration particular wavelength of radiation per unit thickness), the radiation penetration depth will increase approximately by the same factor. To ensure that the product is not spoiled due to overheating, we need approximately 100 pulse durations not give any energy. Characteristically, it is now possible to significantly increase the average power as the energy is distributed not only on the target surface of the product, but also by volume. Furthermore, since the diffusion of solvent from the inner layer greatly increased, it is unnecessary to capture energy and the product cools. When observed under pulsed, to select
the optimal wavelength infrared radiation and correctly calculate the gas dynamics, the product can be heated when it is actually heated, below the ambient temperature. In light of the foregoing ceramics was developed, transforming the primary continuous radiation source in pulsed infrared radiation [3, 74-77; 4, 69-73].
Why Choose infrared is clear — this is an area of water absorption. At first glance it seems that the more the power of the pulses, the better and more efficient will be the drying process. In reality it is not so. The reason is that if the pulses are too powerful, they are too far and most of the energy is lost, is not absorbed by the product. If you go back to the version that we saw when the pulse power exceeds the average 100 times the penetration depth for the same given level of illumination to be about 500 mm. The thickness of the product is only 100-200 mm. At the same time a large part of the energy Un-absorbed lost. Theoretically, this thickness should be increased in the pulse power (30-60) 2 = (15-30) time [5, 1].
For drying the raw cotton used as emitters quartz tube 10 mm in diameter on the surface of which ceramic coated with pulverized grain size of 40-60 microns, which was placed Nichrome spiral. The thickness of the ceramic layer was about 20-40 microns. Studies ceramic radiation spectrum caused by the filament by radiation, showed that the spectrum contains pulses ceramic IR wavelength ~ 16 microns and a duration of about 10 microseconds. Radiators 1000 mm. long attached to the individual blocks are connected in series pairs and connects the power supply 220 (Fig. 1).
Fig. 1. Transmitter unit: 1 - 010 emitters of quartz tube; 2 - connection voltage
In order to use the installation in the factory, we have developed plant for drying cotton column type (Fig. 2).
