Analysis of technical options for the reconstruction of the recycling water system of the electric steelmaking shop of a metallurgical plant

Summary

Process options for the scheduled reconstruction of off-line treatment facilities for the recycling water system of the electric steelmaking shop of a metallurgical plant were analyzed. The reconstruction is being carried out in conjunction with and parallel to the upgrade of the shop without interrupting the operation. The objective of the reconstruction is to improve the quality of the effluent to meet the current technical requirements; increase the flow rate from 1,500 to 2,000 m³/h; and provide for an efficient dewatering and disposal of the sludge generated during the water treatment process. A complicating factor is the lack of available space at the water treatment site surrounded by the existing facilities. Possible options and approaches to upgrading an existing facility based on the advanced Russian and international technologies are analyzed. It is shown that the ECO-PROJECT Group technology based on enhanced single-stage chemical treatment of recycled water in EP OF settling-flocculating tanks and gravity dewatering of sludge in OKUD units, offers a significant advantage in achieving these goals with account of the territorial constraints, operational, time, and economic factors. The presented approaches to solving these problems can find practical and systematic application while looking for a feasible option for reconstructing industrial water supply systems at various industrial enterprises.

Key words

reconstruction , recycling water system , steelmaking shop , EP OF settling and flocculating tank , OKUD apparatus for sludge dewatering , ECO-PROJECT Engineering Company

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UDC 628.179.2

Koutcherenko D. I., Koutcherenko А. D.

Optimal control of recycling water systems

Summary

Method of recycling water system diagnostics that allows decomposing the process of deposit and incrustation agglomerate formation into subprocesses of separate component formation is suggested. The algorithm of selecting optimal directing effects for each component was developed using representative controllable heat exchangers. Tried and tested optimal control modes are transferred to system-wide equipment to minimize material resources and time consumption. With an account for the developments, the basic provisions of the complex network optimal operation theory, and the specific features of the recycling water systems the method of controlling these systems aiming at prevention of progressive deposit and incrustation formation is suggested.

Key words

recycling water system , efficiency criterion , heat-exchange surface , heat transfer coefficient , optimal directing effects

DOI 10.35776/VST.2022.06.02
UDC 628.335.1

Galkin Iurii, Ermakov Denis, Obadin Dmitrii

Development of the technology and results of commissioning the recycling water system of a continuous pipe-rolling plant

Summary

«ECO-PROJECT» Research and Development Company, LLC has developed an innovative technology of recycling water supply for continuous pipe-rolling plants (CPRU) at ironworks. While using traditional, conceptually similar technologies, including coagulation-flocculation, thin-lamellar sedimentation, clarifying filtration and operation in a wastewater free mode, the concentration of suspended solids (iron scale) and mineral oils in the prepared recycling water is several times higher than that regulated by the CPRU manufacturers. The reason is the high concentration of soluble phosphates in the processed recycling water that are stabilizers of disperse systems coming from the rolling process and concentrating during recycling. The low efficiency of sedimentation results in the colmatage of the filtering media of the clarification filters, their decommissioning, forced blowing of up to 30% or more of contaminated recycling water into the industrial storm sewer, and overspending massively more of makeup natural water. The high concentration of mineral oils and abrasiveness of the solid phase of the generated sludge result in the colmatage of the filter press membranes, generation of heavily contaminated centrate that is difficult to clean, and wear of the centrifuges. The developed technology provides for: the removal of phosphates from 5% of the initial recycling water by adding lime milk, CO2 recarbonization of flue gases and clarification; elimination of unreasonable discharge of spent phosphate-containing process lubricant into the recycling water; single-stage coagulation-flocculation treatment of all the feed water in highly efficient sedimentation tanks-flocculators of the EP OF type; gravity chemical-free dewatering in structurally simple OKUD type units. The package of process solutions provides for preparing recycling water of standard quality and eliminating the discharge into the environment; processing scale-oil-containing sludge with a moisture content of 30% for the utilization in metallurgy; reducing the dimensions of the water treatment plants, operating and capital costs. The technology was implemented in the CPRU recycling water supply system of one of the pipe factories with reaching all the design target values.

Key words

recycling water system , ironworks , continuous pipe-rolling plant , coagulation-flocculation treatment , scale-oil-containing sludge

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UDC 66.045.53

Merentsov N. A., Lebedev V. N., Persidskii A. V., Golovanchikov A. B., Kashirin S. E., Kashirina Iu. A.

Heat-mass-exchange packing for evaporative cooling with a developed drip irrigation mode (to be discussed)

Summary

A new heat-mass-exchange packing supporting an intensive drip flow mode for evaporative cooling of water in the water recycling systems of industrial enterprises is presented. The data of an experimental study in the field of hydrodynamics of a new cascade heat-mass-exchange packing supporting intensive drip flow mode are given. The characteristics of the packing device are given in comparison with packings that have received wide industrial application. A classification technique for processing experimental data for heat-mass-exchange packings as a criterion dependence of the modified Reynolds criterion on the hydraulic resistance coefficient is presented. The technique provides for a shot time test of packing materials for their industrial use. Heat-mass-exchange packings focused on the process of evaporative cooling of recycling water will extend over a certain range on the graph λ = f(Rem). An algorithm for calculating the main geometrical and process parameters of a small-sized sectional fan-type cooling tower with intensive drip flow modes for cooling industrial recycling water is presented. The prospect of using the developed heat-mass-exchange packings in the form of a module for disinfecting recycling water in the electric field is noted. This will ensure the constancy of the surface properties of the packing elements and the maintenance of the initial hydrodynamic characteristics, as well as will allow partial preventing the biofilm from overgrowing microorganisms of all heat exchange surfaces of the process equipment.

Key words

recycling water system , hydraulic resistance , hydrodynamic mode , heat exchange packing , retaining ability , small-sized cooling tower

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