New nanocomposites for deep water deoxygenation

New metal-polymer nanocomposites for deep water deoxygenation have been obtained and studied. A macro- and monoporous sulphocation exchanger with a nanometer pore size was used as the polymer matrix, and the metal was nanodispersed copper deposited in the pores of the matrix. A specific feature of the studied nanocomposites is their sodium ionic form, which eliminates the possibility of the formation of soluble copper oxidation products. The established linear dependence of the copper capacity on the number of cycles of ion-exchange saturation - chemical deposition shows that the process of metal deposition into the pores of the matrix does not have significant obstacles during 10 cycles and contributes to the production of high-capacity samples.The high efficiency and duration of the life cycle of high-capacity copper ion exchanger nanocomposites have been shown. Experimental studies of water deoxygenation in column-type apparatus with a nanocomposite nozzle were confirmed by a theoretical analysis of the process dynamics. Experimental data and theoretical calculations showed the deep level of water deoxygenation had practically unchanged values of pH and electrical conductivity. Residual oxygen can be controlled and does not exceed 3 μg/l (ppb).The hygienic and economic substantiation of the expediency of using the obtained nanocomposites is provided. The necessity of using modern nanocomposite metal-polymer materials for deep water deoxygenation circulating in technological systems was analysed. When using this innovation, the metal components of the distribution facilities will be protected from corrosion and, therefore, the hygienic requirements for the water quality of centralised drinking water supply systems will be ensured. Deep chemical water deoxygenation using copper ion-exchange polymer nanocomposites in sodium formallows solving the problem of the corrosion resistance of metals, ensuring that water meets hygienic requirements on a large scale.The competitive advantage of the considered water deoxygenation system in comparison with the known systems is the rejection of the use of precious metals-catalysts (palladium, platinum), pure hydrogen, and complex design solutions. The proposed new nanocomposite installation for water deoxygenation is characterised by its ease of use and can be built into a filter system for water purification.SWOT analysis of the advantages and disadvantages of the proposed method of water deoxygenation showed that its main advantages are the high oxygen capacity of the nanocomposite, low residual oxygen content (3 ppb (μg/l)) in the water, and ease of operation of the deoxygenator. Calculations of the economic efficiency of the nanocomposite have been carried out. The breakeven point is reached when producing only ~100 l of nanocomposite and a volume of sales ~1,600,000 roubles, above which a profit can be obtained. The payback period for an investment of ~15,000,000 roubles is rather short and will not exceed 2 years.

Electron beam welding of rectangular copper wires applied in electrical drives

The so-called hairpin winding technology, which is specially tailored to electrical traction components, deploys rectangular plug-in copper wires in the stator. The fusion welding of the adjacent wire ends is associated with challenges due to the high thermal conductivity as well as the porosity formation of the copper. During this study, the electron beam (EB) welding of electrolytic tough pitch (ETP) and oxygen-free electronic grade (OFE) copper connectors was investigated. Subsequently, the specimens underwent X-ray computed tomography (CT) and metallographic examinations to characterize the joints. It was discovered that the residual oxygen content of the base material is responsible for the pore formation. With only a very low level of oxygen content in the copper, a porosity- and spatter-free welding can be reproducibly realized using the robust EB welding technology, especially for copper materials. By optimizing the parameters accordingly, joints exhibiting a low level of porosity were achieved even in the case of the alloy containing a high amount of residual oxygen. Beyond this, detailed analyses in terms of pore distribution were carried out and a good correlation between technological parameters and welding results was determined.

The influence of water filtration rate on the efficiency of its oxidization on iron-containing redoxite

Experimet to determine the effectiveness of iron-containing redoxites on the efficiency of water deoxidation. In the course of the study, the dependence of the efficiency of water deoxidation on the filtration rate was determined. The filtration rate was varied in the range from 5 to 25 mph. The residual oxygen content and the dissolved iron content in the water were determined. It was shown that with increasing filtration rate within these limits, the residual oxygen concentration increases from 0.1-0.2 mg/dm3 to 0.9-1.0 mg/dm3. The residual oxygen content depends not only on the filtration rate but also on the reaction of the medium. An increase in the residual oxygen concentration with increasing pH of the medium from 6.7 to 10.0. Residual iron content depends little on both the filtration rate and the reaction medium and in all cases did not exceed 0.2 mg / dm3. In this work, the dissolution of iron in general was determined by preliminary preparation for the work of iron-containing redoxite. When used in the installation scheme, in addition to the column with iron-containing redoxite, also columns with cation exchange resin KU-2-8 in Na-form, almost complete removal of iron ions from the water and natriation softening of tap water was noted. In the case of sodium-cationized water, the extraction of iron from water will be observed for a long time, given the low concentration of iron ions in the water and the high capacity of the cation exchange resin in iron ions. In addition, sorbed iron (II) ions on the cation exchange resin are oxidized by oxygen residues to iron (III). The latter, at elevated pH, are hydrolyzed, which is the reason for the restoration of capacity and cation exchange resin by divalent iron cations. In the case when after the column with iron-containing redoxite used anion exchange resin AB-17-8 in sulfite form, complete extraction of oxygen from water was achieved. Given that the oxygen concentration in water with the use of iron-containing composite decreased by 10-40 times, the load on the anion exchange redox will decrease proportionally, which means that the duration of the anion exchange redox filter cycle will increase in the same proportion. The use of iron in the second stage of the anion exchange resin in the SO32- form remained unchanged, but complete oxygen extraction was achieved. The option is quite promising for implementation.

High-efficiency catalytic reduction of residual oxygen for purification of carbon dioxide streams from high-pressure oxy-combustion systems

Cobalt–manganese composite catalysts in a reverse-flow fixed-bed reactor showed excellent activity and selectivity for reduction of residual O2 for CO2 purification from pressurized oxy-combustion flue gases.