Figure 1 – Schemes drobe-metnyh installations with rolgangolly conveyor RATIOJET Series.
Faculty of mechanics and engineering
Speciality: Computer control of hydravlic and pneumatic systems
The work purpose is a research of a hydro-pulse method of clearing a metal rolling mill scale from.
Research problems:
1) accumulation and processing of the information on scale formation on a hire surface;
2) search and processing of data on methods of removal of scale;
3) the review of existing devices for scale removal;
4) recommendations about application of a hydropulse way of clearing.
Now in an iron and steel industry there is the major problem of manufacture of qualitative rolling production. In the basic way for which account high quality of hire is provided, it is considered effective removal of scale from a surface of metal of hire. Scale is formed on cast preparations as a result of interaction at heating of a surface of production with oxygen of environment.
At present there are many various ways of removal of scale and a design of mechanisms for their realisation, but they possess essential lacks. Thus for today especially a vital topic of research and working out of new methods of removal of scale which will allow to increase their efficiency and it is essential to lower expenses.
Research of a hydropulse way of clearing of metal rolling from scale.
Now there is a considerable quantity of various technologies of clearing of a surface of hire.
Scale removal is made chemical, mechanical, hydraulic and other ways.
Mechanical ways of clearing concern it pesko-jet, drobe-peskostrujnyj, drobe-metnyj, hydro-abrasive, abrasive and iglo-milling.
Drobe-jet and especially pesko-jet pneumatic clearing of moulding in the modern foundry is applied in rare instances or not applied.
Company "SciTeeX" — the leading manufacturer drobe-myotnogo the equipment in the world. Design bureau SciTeeX RME GMBH in (Germany), in the world centre of working out of drobe-jet technics develops the equipment according to last achievement in area drobe-myotnoj processings. Manufacturer SciTeeX Sp.z.o.o. (Poland) it is equipped by the most advanced equipment and technologies for manufacturing and drobe-myotnogo the equipment and delivery to the markets of all world [1].
The hydroabrasive way of clearing consists that from the installation tank on a cleared surface of a product through a nozzle under the pressure of compressed air the stream of a mix of quartz sand and waters (pulp) goes. As an abrasive material quartz sand, a ground granite and slag can serve [2].
One of the basic lacks of a method is a necessity of compressed air with giving 240 m3/hour and pressure 0,6 МPа, that is necessity of the compressor or a shop network.
There are some designs of the hydroabrasive installations, different systems of mixture of an abrasive material with water and givings of a working mix to a nozzle.
For abrasive clearing of hire in metallurgy use plainly-grinding, circular grinding, bestsentrovo-grinding, modular, lentochno-grinding, abrazivno-detachable, manual pendant and stationary machine tools [3].
Scale removal is carried out on iglo-milling installations. Iglo-milling process represents cutting from a surface of metal of oxides and scale end faces of elastic-mobile delays [4].
Iglo-millings in metallurgy it is applied for removal of scale from a surface of large high-quality hire from carbonaceous and the is low-alloyed steels.
Hydraulic removal of scale. At separate metallurgical industrial complexes, in system gidro-sbiva pressure of water to 18 МPа is used. These systems gidro-sbiva do not provide creation of a necessary high-speed pressure of a stream of the water, capable effectively to clear sheets of scale.
Over creation of more effective and less power-intensive systems gidro-sbiva scales work many foreign firms [5].
The German firm "Woma – Apparatenbau and Co GmBH" offers system gidro-sbiva with working pressure 20,0-50,0 МPа and the reduced expense of water at the expense of application of a rotating per capita beam. The beam is supplied by the nozzles, allowing to make repeated water streams.
Considerable advantage of a hydropulse method of clearing of hire in comparison with other methods of clearing is a smaller power consumption.
Creation of the generator of pulse streams (GPS) [6] became result of long-term work of employees of Donetsk national technical university in the field of working out of hydropulse devices. The generator of pulse streams provides transformation few-account (to 0,0015 m3/c) a stationary stream of a working liquid of a high pressure (to 32,0 МPа) in pulse the raised instant expenses (to 0,025 m3/s) same pressure. Capacity of a stream in a water shot power consumption of the pump makes nearby 500-700 kVt, thus that of 55 kw. The big capacity of a stream provides considerable destroying ability of a stream.
Advantages of a hydropulse method:
1) universality (possibility to process a surface of difficult geometrical forms);
2) preservation of the form and a roughness of a processed surface;
3) low power inputs;
4) ecological compatibility of a method;
5) work on a closed cycle;
6) explosion safety.
I have carried out the analysis of existing methods of clearing of hire from scale, have revealed their merits and demerits. I have proved efficiency of application of a hydropulse way of clearing.
Research prospect - calculation of rational parametres of a hydropulse method of destruction of scale.
At present work is in a working out stage. Work end results can differ from presented on a site.