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Karandashev Konstantin

Theme of master's work:

Investigation of the kinematics, the calculation of energy-power parameters and design of the manipulator for maintenance of cluster ladle gates equalizer type at the converter shop of OJSC "MMK im. Ilic"

Scientific adviser: Eronko Sergey

The abstract on a theme of final work

Introduction

        The basic direction of development of steel-smelting manufacture in modern conditions is working out of progressive technologies and the new equipment, providing metal products improvement of quality. The special role is thus taken away to the final stages of process of reception of cast preparation or an ingot - extramodular processing and pour the steels, closely interconnected among themselves.

        The technology pour metal is constantly improved. Technical progress in area pour steels for last two decades was characterised by wide introduction of cars of continuous moulding of preparations, and also application instead of traditional lock devices of more reliable in work for a ladle the shutters which have provided successful development of the majority of ways of extraoven processing of a steel.

        Now practically at all metallurgical enterprises of the country for the dosed out release of a steel from a ladle in ñapacity for metal are used sliding shutter and works on the equipment by them not only the basic, but also intermediate ladles MCMP are already conducted. At the branch enterprises are maintained about ten designs of the shutters, different by drive type, way of assemblage and the mechanism clamp a mobile fire-resistant plate. [1,ñ.3]

        Being based on the previous operating experience and the analysis of principal causes of refusals of the given devices, the basic requirements present to shutters pour steels a ladle are formulated:

1. The reliable pressing of a mobile fire-resistant plate excluding pass of a liquid steel;

2. High wear resistance of rubbing metal parts;

3. Absence deformation details at influence of heats;

4. Sufficient for overcoming of peak loadings capacity and reliability of work of a drive in extreme conditions;

5. Low cost of manufacturing;

6. Simplicity of service.

The work purpose

        The purpose given magistracy works is kinematics research, calculation of power power parametres and designing of a cassette shutter balance type for ðàçëèâêè steels in conditions at the converter Open Society shops "ÌÌÊ it. Of Ilyich". Researches will be is spent on real model shutter for a ladle. Also the estimation technic - economic efficiency of the offered design will be given.

Theme urgency...

        Systems of the sliding shutters used for dosed out release of a steel from for flood and intermediate ladles, demand the further perfection as technical and economic indicators of processes of reception of ingots appreciably depend on efficiency of their work and cast it is continuous preparations.[1]

The review of researches on a theme in DonNTU

        The Donetsk technical university together with Makeevsky metallurgical industrial complex develops a shutter design balance the type supplied with an electromechanical drive (fig. 1). The shutter includes the top and bottom fire-resistant plates established in steel holders. The holder of a mobile plate leans against the rollers typed in a separator and placed in directing grooves of two balance weights. Balance weights are fixed on the G-shaped levers connected with a holder of the top plate with the help áîëòîâûõ of couplers, and suppose the big deformations of system (about 0,1 mm on loading ton) that allows to compensate discrepancies of assemblage. G-shaped levers, thus, carry out a role of elastic elements with which help it is possible to lower requirements to accuracy of installation of fire-resistant plates in metal holders.

Drawing 1 – The shutter balance type:

        Industrial application of a shutter of this type within 10 years in martin shops of Makeevsky metallurgical industrial complex and metal works of A.K.Serova on 250 and 100-ton ladles spilling a steel allows to estimate its advantages which are reduced to the following:

1. It is reduced deformation shutter elements at heating that has allowed to replace heat resisting steels the average maintenance of carbon (type of a steel 45) for manufacturing of all details;

2. Uniform distribution of loading on a contact surface of plates is provided, and equally effective is directed on a channel axis spilling a steel a glass that completely excludes necessity of the control of parallelism of a fire-resistant plate and directing mobile holders in the course of assemblage;

3. The admissible warp of a surface of a fire-resistant plate and directing, corresponding to effort increase in clamping bolts from nominal to maximum (from 50 to 150 êN), makes 3,7 mm for all length of a plate that much more actual, received at pressing plates in a mobile holder at shutter assemblage;

4. Necessity íàïëàâêè is eliminated and polishings of basic surfaces, are excluded teases of surfaces of a friction and their deterioration is reduced.

        Thanks to the specified features the shutter possesses raised reliability (the quantity emergency ðàçëèâîê makes 0,3-0,4 % that in 2-3 times is less a than average index for shutters of other designs). [1, with. 48-50]

        The shutter on which researches will be carried out in the given work, has a vertical variant of disclosing (Draw. 2).

Drawing 2 – Variants disclosing The shutter balance type:

        Short duration of the period of melt of a steel in the converters functioning in a complex with installations a ladle-furnace and high-speed MNLZ, providing moulding of preparations by long series, has demanded reduction of duration of preparation for work spill devices. It became possible with working out sliding the shutters of the cassette type allowing essentially to raise route turnover of ladles at the expense of possibility of replacement of the fulfilled complete set of fire-resistant products without removal of a shutter from a ladle and its sending in sliding a workshop. At creation such system of flood of a steel considered that circumstance that because of increase in duration of a finding metal ðàñïëàâà in a ladle in case of performance in it of technological operations on to lower acidity, and to refinement there are considerable deformations of details of the shutter, caused by their heating. Therefore basic knots of a mobile part of a shutter should not only provide indemnification of these deformations, and and keep reliable contact of working surfaces of the fire-resistant plates, excluding backlash occurrence between them even in case of action wedge increases the force arising during destruction by a mobile plate of a metal crust, often formed on walls channel of release of a steel

        At creation of cassette shutters of new generation authors have chosen the modern conceptual approach based on realisation of a principle of rationality of projected mechanical system, assuming reduction to a minimum in the kinematic scheme spill devices (Draw. 3) superfluous (passive) communications. [3]

Drawing 3 – Cassette shutter balance type (a) and its components (b):

        It have reached thanks to application balance and hinge systems of pressing of a mobile holder and to its placing on two linear roller bearing that has provided self-installation of the bottom fire-resistant plate concerning top and loading decrease on a drive. Easings of negative influence of thermal influence on working capacity of mechanical system bucket have achieved a shutter by means of application of a semifixed mode of pressing of fire-resistant plates by means of two screws and the special levers supposing considerable elastic deformations. In need of replacement of the fulfilled complete set of fire-resistant products it is necessary to weaken an inhaling of two screws and to turn a mobile part of a shutter on 90 hailstones, concerning the top holder, providing with that an easy approach to ceramic parts spill the devices, fixed in its metal holders by means of elements with a carving. After complete set change refractory shutter assemblage carry out in return sequence, supervising with the help dynamometric a key the demanded moment of an inhaling of two screws, making 100 N*m.[4, 5]

        Results of industrial approbation balance a shutter with bolts pressing of plates (draw. 4) have proved the accepted technical decisions, allowed to use for manufacturing spill the device a constructional steel instead of heat resisting and by that considerably to lower its cost, and also to simplify service and operation.[6]

Drawing 4 – Cassette shutter balance type in the industry

        Efficiency of use sliding systems appreciably depends from reliable and non-failure operation of the drive which is carrying out moving of a fire-resistant element, locking the channel for steel release of a ladle or the melting unit. Therefore the drive should correspond to a technological level of a sliding shutter and to satisfy to a number of requirements (compactness; capacity, sufficient for overcoming of peak loadings; reliability of work in extreme conditions; accuracy of regulation of a stream of the liquid steel, allowing to automate management of work; possibility of duplication in case of emergency power cutoff).

        As it is known, sliding shutters can be completed by a drive of hydraulic, pneumatic or electromechanical type. Each type has the merits and demerits shown in higher or a smaller measure depending on a number of factors, therefore at a choice of the scheme of a drive the preference is given to that which most answers working conditions of concrete steel-smelting shop.

        The electromechanical drive has no alternative in case of application of rotary shutters. Thus it includes the electric motor lowering a reducer and a low-speed tooth gearing which can be with direct teeths or conic. In shutters with forward moving of the fire-resistant plate blocking the final channel spill of a ladle, a mechanical drive apply much less often in comparison with the hydraulic. It contains the electric motor lowering a reducer in the structure, combine with the mechanism, reformative a rotary motion of a low-speed shaft of a reducer in forward which is informed a mobile holder spill devices.[3]

        Traditionally all updatings of shutters of a design of DonNtU with progress of a fire-resistant plate were completed with the electromechanical drive which general view is shown on draw. 5. Thus the reducer on a ladle is mounted permanently, and the electric motor establish only for a while spill and attach by means of a screw clip.[3]

Drawing 5 – the General view (a) and the placing scheme on a ladle (b) an electromechanical drive sliding a shutter:

        Thanks to electric motor possibilities to overcome short-term overloads, and also crank mechanism to develop in final positions of force, in tens times exceeding nominal, the electromechanical drive allows to carry out moving of a mobile plate even in case of metal hardening in the channel for steel release

Drawing 6 - Visualization of work of the mechanism of a cassette shutter balance type

        Thus the effort shift a mobile holder with the bottom fire-resistant plate for the specified variant of support sliding devices is defined from expressions:

        where è - sliding friction factors between working surfaces of fire-resistant plates and between a pin and a roller accordingly;

            f - friction factor êà÷åíèÿ;

            D è d - diameter of a roller and its pin accordingly;

            Ð - force of pressing of plates.

        In emergencies the drive allows to open and close a shutter manually. The special ratchet device which in case of need put on the free end of a high-speed shaft of a reducer is for this purpose applied and with its help provide system functioning in a manual mode, moving with the lowered speed a mobile plate from one extreme position to another.

        The mechanical drive is simple in manufacturing, equally reliably works in the conditions of low and heats, possesses in comparison with hydraulic and pneumatic higher autonomy as a food of its electric motor carry out from a network spills the crane.[7]

Conclusion

        In further, after designing and carrying out of researches of kinematics of a shutter, after calculation power power parametres and reception results of bench tests sliding systems, the estimation technic - economic efficiency of the offered system will be made.

        Thus, researches sliding systems spent in given üagistracy to work will serve the further development and introduction in practice of the highly effective equipment used in steel-smelting manufacture for realisation of progressive technologies, providing improvement of quality of let out metal products and decrease in expenses for its manufacturing.[3]