Динамика машинных агрегатов пильного джина с семяотводящим устройством и конденсора с пульсирующим потоком

Аннотация

Topicality and demand of the subject of dissertation. One of the key problems of complex measures of anti-crisis program, worked out under the guidance of the President of the Republic of Uzbekistan Islam Karimov, is - «...In the first turn, further acceleration of modernization, technical and technological re-equipment of enterprises, wide-range implementation of modem flexible technologies. This, first of all, concerns basic fields of economy branches, export-oriented and localized productions. The problem is set - to accelerate the programs of modernization, technical and technological re-equipment of production, conversion to international quality standards; this will allow to provide for solid position in both foreign and domestic market Conversion to market economy arises in Uzbekistan one of the most important problems - to increasing a competitiveness of cotton product. Necessary condition of its solution is considerably improving the condition of salable product of fiber with optimal quality characteristics; fiber being the basic product of cotton-cleaning industry. So, technical re-equipment, provision of modem engineering and technology, development of mobile, operating and meeting market requirements competitive production - arc the most important strategic problems of cotton-cleaning industry by resolution of the Cabinet of Ministers of third of april 2007 year №70 «On the program of modernization and reconstruction of ginneries in the period 2007-2011». In existing production lines the halt of any machine of the line leads to downtime of the whole complex or to operating the parallclly installed equipment with increased load. The first case is accompanied with free-running operation of coupled equipment (at short-term downtime) or with additional time necessary to clean coupled machines and startup of the complex after the halt. In the second case while operating with increased (above-standard) workload, the quality of cotton product becomes poor and resource-saving of technological machines is lower. All of these testify to reasonability of carrying out investigations on the development of machine units which meet requirements in productivity of machine configuration in terms of compatibility, dimensions and, finally, resource and energy saving. Competitiveness of output product in market conditions is determined by its quality and cost, specified first of all by expenditures on its manufacturing. In manufacturing of a fiber lowering the production expenses in cotton plants may be achieved due to increase in efficiency, regular work of saw gins and cleaning effect of a condenser. Stability of operation of saw gins and condensers mainly depends on uniform feeding of cotton; here the importance of a feeder is very high. Improvement of existing saw gins and condensers, from the point of view of productivity increase and cleaning effect together with the least energy-consumption on the basis of known technical solutions, has practically exhausted all its possibilities; so the search of the means should be done on the basis of principally new unconventional technical solutions. Here arises a necessity to work out a feeder which will provide loosening, cotton cleaning before ginning and its uniform feeding into working chamber with specified production capacity and provision of required quality of fiber. To fulfill compatibility of machine units of a feeder and working chamber of saw gin in dimensions and production capacity it is necessary to work out a new structure of working chamber. So, development of dynamics of machine units of the processes of uniform feeding, ginning and cleaning of fiber in condenser with minimal energy-consumption presents an urgent problem; this thesis is devoted to the solution of this problem. Purpose of reseach is a development on the basis of studies of the dynamics of machine units of new structures of saw gin and condenser, which satisfy requirements of productivity, compatibility and energy-consumption and conservation, meeting the requirements in cotton fiber quality. Scientific novelty of dissertational reasearch consists in the following: two-drum pin feeder, working chamber of saw gin with seed retractor device and consenscr with pulse air stream; methods and program software of calculation of dynamic processes, occuring in structures of machines of saw ginning have been worked out (675, 2354, IAP 02992, IAP 04037, FAP 00536, FAP 00589); the regularities of changes of quality characteristics of fiber, seed and productivity of saw gin and fiber condenser in relation to characteristics of seed retractor pipe and pulsator have been revealed, allowing to rationally choose the modes and parameters of machines for cotton cleaning and ginning; the regularities of changes in roller loading of 156-saw cylinder, seed retractor pipe and screw have been determined, as well as their cutoff rotation frequencies with account of technological resistance in working organs of gin, which allow to choose its dynamic and structural parameters; mathematical model of machine units “feeder - saw gin - fiber condenser” has been worked out; it provides less energy-consumption and cost price of cotton fiber in processing of cotton. Conclusion On the basis of carried out theoretical and experimental study on elaboration of new generation of machines of primary processing of cotton the following conclusions and recommendations were formed: 1. Analytical review of literature and study of machine operation in cottonprocessing industry allow to reveal that according to existing technologic regulations scientific grounds and structures of working machines were developed. But the problem of efficiency increase of the system «cotton cleaning - saw ginning and fiber cleaning in condenser» as machine units insuring significant increase in productivity under least power consumption per the unit of product remains an actual one. Directions of investigations on development of new feeder -cleaner with uniform feeding of cotton into saw gin of working chamber with additional retraction of seed and fiber condenser with inclusion of pulse air stream into technologic cycle were determined. 2. Structure of gin feeder with two successive pin drums and gauze surfaces, covering them, was substantiated; design-technological scheme of operation, dynamic and mathematical models were worked out; differential equations of motion of machine unit of a feeder were drawn. With Gauss-Zaydel method on criterion of the longest pass of cotton along gauze surface and experiments conducted on laboratory-stand device some rational parameters of a feeder. Worked out algorithm and design program allow to recommend the drive. 3. By mathematical simulation of the motion of cotton segments and seeds in working chamber of saw gin it was stated that an assessment of operation productivity may be conducted on the basis of study of regularities of changes of their tangential velocities. Gin structure with reduced step of location of saw disks on the shaft and working chamber with seed retractor device, which consists of hollow rotating cylinder pipe with longitudinal slits and screw, located inside the pipe, was worked out. Rational geometric and kinematic parameters were established. 4. Dynamic and mathematical models of machine unit of saw gin with seed retractor device were built, different characteristics of the system «engine - executive machine» were analyzed. Calculations show that to provide uniform rotation of saw gin, elastic dissipative parameters of a drive. 5. On the basis of the Method of finite elements in the form of displacements, the methods of determination of force, strength factors and critical velocities of working shaft of cotton-processing machines were developed and recommended for engineering calculations. On the example of calculations of new gin 5DP-156 with seed retractor device, design studies in assessment of strength of the shaft of saw cylinder, seed retractor pipe and screw were carried out and it was stated that recommended parameters meet requirements of strength of similar structures. 6. On the basis of the method of linear programming some production resources of machines were calculated; they allow to decrease power consumption and hence to provide resource-saving due to optimal number of machines of different technologic purpose under the best quality characteristics of fiber in length 33,71mm, and output 33,92%. Using the method of planning of full-factor experiment of 2n type CKP experimental studies of assessment of productivity of worked out two-drum pin feeder together with saw gin were conducted and nine equations of regression to determine productivity of operation of a feeder and gin, fiber length, dirt in raw cotton, fiber output and so on were drawn at three levels of saw gin extensions and frequency of rotation of seed retractor pipe; optimal parameters of the latter were calculated as respectively X]=5l,97»52mm and *2=388,4 min1» 400 min’1. Here productivity of feeder in cotton reaches 7000 kg/hour, and saw gin in fiber - 2242 kg/hour, fiber length is 33,71mm. 7. Calculations on estimation of efficiency of application of a gin with seed retractor device in production line of processing of poorly cleaned growth of mediumstaple cotton, show 1,1 kWt or 2,9% decrease in specific energy-content per unit of product (fiber) in comparison with industrial gin - 5DP-130, with experimental industrial gin - DPZ-180 - 0,9 kWt or 2,7% decrease and with the best foreign sample -«Continental eagle» 10,92 kWt or 28,7% decrease. At rational composition of technological succession from transfer conveyor of cotton to bend transporter for fiber bales on one program of processing of 30000 ton of raw cotton per year, power consumption decreases from 480,5 down to 407,7 kWt due to increase in productivity from 12% to 50%, and economic benefit is 96,5 mln.soum. 8. Design-technological scheme and design program of motion of fiber ball on the surface of gauze drum were worked out, rational values of frequency of rotation of shutters of pulsator - 370 min , suction force of fiber - Рвтах=0,245 H and ratio of areas of shutters and pipeline - 0,7 of fiber condenser with pulse air stream were determined. Here minimal mass part of defects and dirt admixture in fiber were revealed at total relative velocity S’=l 1,87 m/s. Worked out algorithm and design program of the dynamics of machine unit of fiber condenser K.VVB with pulse air stream allow to recommend the moments of inertia - 35=0,003056; 36=0,05915 kg-m2; drive stiffness - C/=66,0275; C2=147,63; Сз=113,204; C4=13,518 Hm/rad, which ensure minimal power consumption and non-uniformity of rotation of gauze drum. As a result an additional cleaning effect (13%) is reached. So, scientific grounds of the solution of the problem of development of machine units of two-drum feeder, saw gin with seed retractor device and fiber condenser with pulse air stream arc considered in the thesis; their implementation would contribute greatly into modernization of the branch of processing of raw cotton and would increase the competitiveness of the product of cotton-cleaning production.