Cleaning of concentrated emulsion sewage of electric-weld pipe lines

Existing processes of cleaning emulsion sewage are based on either physicochemical technology with application of complex of reagents – nonorganic electrolytes and organic flocculants, resulting in obtaining highly-mineralized purified water, which cannot be used for technical water supply, or based on complicated technologies of electrocoagulation and ultrafiltration. This required elaboration of a new technology and equipment for cleaning concentrated emulsion sewage, in particular, those containing emulsol of Wedolit EP-5 grade, used for hydro-mechanical expanders of electric-weld pipe lines. The technology stipulates a successive introduction of a reagent – suspension of alumo-silicate based hard-phased sorbent and solution of flocculant of cation type Praestol-650ВС – into emulsion sewage, their mixing with emulsion water in a definite mode, sedimental differentiation of the formed phases in a precipitator-flocculator “ЭП ОФ”, gravitation concentration and dewatering of the obtained sediment at vacuumfilter. The dewatered sediment can be utilized in cement industry and metallurgy. It was shown that application of the hard-phase sorbent does not result in an increase of mineralization of purified water and enables to use it for technical purposes. The group of companies “ECO-PROJECT”, Ekaterinburg, accomplished a project for Chelyabinsk pipe-rolling plant, elaboration and manufacturing of equipment, as well as commissioning and start-up of the equipment. The elaborated technical solutions in the process of equipment running showed a high efficiency and can be used as a base for creation of facilities of any productivity for cleaning multi-type emulsion sewage at enterprises of various industries.

Experimental Study of Features of Thin-Walled Pipes Sizing in the Line of a Pipe Rolling Plant with an Automatic Mill

The aim of the study is to establish the actual level of working loads on the roll drive line of the sizing mill installed as part of the PRP-220 with an automatic mill, when switching to the production of steel pipes from increased strength group. The study is based on a complex experimental and theoretical analysis. After the processing of the results of experimental studies a comparison of the most loaded sizing route for a thin-walled pipe with a diameter of 244.5 mm and a wall thickness of 8.9 mm (D/S = 27.5) made of steel of strength group “D” was made with the route for a pipe with a diameter of 177.8 mm and a wall thickness of 9.2 mm (D/S = 19.3) from steel of strength group “E”. Graphs of the observed processes are presented, as well as calculated predictive values of sizing of thin-walled pipes for steel of strength group “E”, obtained on the basis of an experimental-theoretical analysis of the growth of flow stress. Recommendations have been given for improving the equipment of the PRP-220 sizing mill for the production of pipes with increased diameters from steels of increased strength groups.

EZTM experience in designing and manufacturing of rolling mill main drive gearboxes

The experience of the Electrostal Heavy Machinery Plant (EZTM) in designing and production of special gearboxes and gear stands for main drive of various rolling mills is summed up. The specifics of section and ball-rolling mills, piercing and reduction mills, mills for cold rolling of tubes and mills for the production of reinforcing bars are considered. It was shown that at designing of special gearboxes for the main drives of rolling mills, the designer, taking into account the parameters of the mill, must build a cyclogram of their loading, which depends both on the range of rolled products and on the variability of loads within the rolling cycle of one billet. In the Designing Department of EZTM, the strength calculation of gears of different types is carried out in the REDUK 4.3 software package, which allows performing strength calculations of gears taking into account the expected loading cyclogram. At the same time, the program provides the initial data for calculating the shafts and bearings, i.e, the forces in engagement and the rotational speed of each of the shafts for the first stage of the cyclogram. The geometrical parameters of the gears are optimized according to the criterion of contact and flexural strength, both between the stages and within each of them.The load sequence diagram depends both on the range of rolled products, and variable loadings in a rolling cycle of a workpiece. Geometric parameters of gears are optimized by contact and bending equal strength, as between the stages as within each of them. Carburizing, hardening and grinding of teeth are provided and secured technologically. Currently, the gearboxes manufactured by the plant are successfully operated at many metallurgical enterprises, both in Russia and abroad. Among them, the gearboxes of main drive of the piercing mill of the Seversk Pipe Plant, the mills for cold rolling of tubes in the USA and China, the section mills at the Yartsevo Casting and Rolling Plant, the reduction mill at the Dnepropetrovsk Metallurgical Plant, etc.

The Calculating Method of Thinning Pipes Ends before Rolling in the Reduction Mill

In this article it is discussed one of the main directions of improving the rolling tubes technology on a pipe-rolling plant with a continuous mill, in order to reduce the pipe-ends cut. A method for preliminary end sections thinning modes, calculating during rolling on a continuous mill, to compensate for wall subsequent thickening in the reduction mill, has been developed. Method distinctive feature is the calculation of end thickening volume, which must be reduced by a specified quantity when end sections rolled. The sequence of technological calculations is given. The results of pipe reduction computer simulation by regular rolling modes, and modes calculated by the proposed method, are represented The analysis of the simulation results showed the possibility of thickened ends length reducing of at least 10%.

The dynamics of the centreing mechanism of piercing mill mandrel of the pipe-rolling plant

The paper presents the results of the vibrodiagnostics of a centering machine mechanism for holding piercing mill mandrel N1 of the pipe-rolling plant (PRP) 350. In the paper, it is established that vibration acceleration of a bearing roller lever of the centering machine mechanism for holding piercing mill mandrel during milling of an Æ282х50 mm shell, steel 20 reaches 5…12 m/s2, and of the upper roller’s vibration frequency is 33.3 Hz. The paper presents the results of the thickness measuring of the Æ282х50 shell, steel 20 after using the piercing mill N1 350. The results shows the distinctive influence of the dynamics of the milling holding mechanism rod. The system is put forth for calculating the energy-power parameters during the realization of the technical process for making shells of the required specifications in a piercing mill. The paper establishes the value of the milling axial resistance to the flow of the milled metal (taking the calibration values into account). The paper presents a refined system for making a dynamic model for the piercing bill milling holding mechanism rod with the milling calibration parameters taken fully included. A differential equation for the milling rod movement is made, specifically for the dynamic model of the PRP piercing mill mechanical system. The dynamic values of the mechanical system are refined, which is used as a starting point for solving the tasks dealing with the analysis of the PRP piercing mill milling rod’s vibroactivity state. In order to decrease rod vibroactivity levels, the paper recommends choosing rational milling calibration and to set the shell milling modes using mechanical system dynamics modelling during the corresponding stages of the design of technological processes. The paper pro-poses a scheme for modernization of the PRP 350 piercing bill exit side by switching the centering machine rod system holding bridges gear to proportional hydraulics. Keywords: piercing mill, vibration diagnostics, thickness measurement, piercing, sleeve; difference in wall thickness, energy-power parameters, calibration, mandrel, vibroactivity, dynamics, mandrel retention mechanism.

Study on Thermal Operation and Design of Ring Furnace of the Pipe Rolling Plant

High productivity of rolling and pipe rolling mills, good quality of finished metal products is possible to provide in the presence of powerful heating furnaces, well heating the metal with minimal oxidation and decarburization. Such conditions are provided by ring furnaces which are widely used for heating the preparations at rolling of pipes, wheels and bands of the railway rolling stock. The purpose of the heat – receiving structure of the metal, providing a set of physical and working properties, or impart to these materials the ductility required for subsequent machining. The article deals with the design and thermal performance of the ring furnace operating at ChelPipe’s Pipe Rolling Plant No.2. The problems arising during the operation of the thermal unit are analyzed. The paper describes the calculation of heating of metal and heat balance of the ring furnace. In the course of the analysis of the results of design studies, the shortcomings of the existing heat recovery system are revealed and measures for the reconstruction of the furnace to reduce fuel consumption and increase productivity (replacement of the existing brick lining with fibrous, the use of regenerative burners, the use of non-water-cooled partitions, etc.) are proposed. The paper analyzes the design and thermal performance of the ring furnace for heating of pipe billets before rolling. It shows a heat balance of the ring heating furnace and provides measures for furnace reconstruction aimed at reduction in fuel consumption and increase in efficiency: replacement of the existing lining with fiber lining, use of regenerative burners, application of non-water cooled walls.