UDC 621.929
Grigor’eva Anastasiia, Abiev Rufat
Study of the suspending process with the use of a conical mixer through the example of the process of sulfuric acid neutralization at Sviatogor JSC
Summary
The process of suspending solid particles in a liquid by means of mechanical mixing is considered. A technique for the selection of mixing devices with account of the geometry of the mixer has been developed and described. The methodology is based on the semi-empirical Zwietering model, supplemented in the course of additional studies by Ayranchi and Kresta. Various modes of the suspending process have been studied. On the basis of theoretical relationships, a conical mixer with a special blade geometry was developed and tested in laboratory conditions resulting in a highly efficient suspending process. The empirical suspending coefficient of Zwietering and Ayranchi–Kresta was calculated resulting in the possibility to calculate the required parameters of the mixer on a scale of industrial reactors. The efficiency of the new mixing device was proved during industrial tests in a chemical reactor for quenching sulfuric acid with lime milk. Owing to the use of a conical mixer the reaction rate was reduced from 60 to 38 minutes with a 40% reduction in electricity consumption. It is proved that a sufficient condition for the enhancement of the neutralization process will be eliminating the sedimentation of the suspended sludge to the bottom of the reactor, i.e. the suspending process in the bottom part shall be enhanced.
Key words
sulfuric acid , conical mixer , mixing , suspending , neutralization
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UDC 628.16.066.1:628.164-92
DOI 10.35776/VST.2023.08.01
Bobinkin V. V., Vukolov Oleg, Gizzatullin Artur, Kasatochkin A. S., Kostylev Evgenii, Larionov S. Iu., Oliunin Sergei, Panteleev Aleksei, Riabchikov Boris, Savochkin Andrei, Shilov Mikhail
Industrial horizontal intensified clarifier for water
softening/decarbonization by liming
Summary
Chemical softening methods have been widely used in the water treatment practice. As shown in the previous review, the chemistry of the process has remained unchanged over the past 100 years; however, the instrumentation of the process has changed. This equates to significantly increase the capacity and efficiency of the devices. Research work has been carried out on designing domestic intensified apparatus for softening/decarbonization of water by liming; and their introduction into industrial practice has started. Studies of the developed version of the multi-chamber horizontal clarifier with liming of Aquafloc type were carried out. The boundary parameters of the process of water liming with coagulation with iron salts were determined. It was established that the improved mixing, acceleration of chemical reactions and recirculation of carbonate sludge (seed) provide for the optimization of the sedimentation process to reduce the coagulant consumption and significantly improve the sludge characteristics. Essential advantages of the clarifier are as follows: smaller dimensions and metal consumption compared to classical clarifiers, as well as a short time to reach the operating mode. Thereby, an Aquafloc clarifier can be delivered to the site ready assembled, ready-to-use and with anti-corrosion protection that significantly reduces the time and cost of assembling at the facility. The concentration of dry matter in sludge reaches 8%. In comparison with the existing VTI-630 clarifiers, Aquafloc clarifier showed similar results in terms of chemical parameters and the best in terms of the concentration of suspended solids. In terms of water consumption for own needs, the clarifier turned out to be at the level of VTI apparatus that have a total blowdown volume of 2–4%.
Key words
coagulation , suspended layer , hardness , enhanced treatment , water , mixing , chemical water softening , liming , horizontal clarifier
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UDC 628.16.066.1:628.164-92
DOI 10.35776/VST.2023.03.03
Savochkin Andrei, Kasatochkin A. S., Panteleev Aleksei, Riabchikov Boris, Larionov S. Iu., Gizzatullin Artur
Designing horizontal clarifiers and studying the efficiency of the water liming process
Summary
Chemical softening methods have been widely used in water treatment. As shown in the previous review, the chemistry of the process has remained unchanged for the past 100 years; however, the instrumentation has changed. This provides for increasing significantly the capacity of the devices and their efficiency. Mediana-Filter R&P JSC carried out research on the development of domestic intensified devices. The studies were carried out in a small-scale laboratory three-chambered horizontal clarifier with a lamellar settling tank and in a pilot clarifier with a variable chamber volume. The optimal procedure of introducing chemicals, the minimum and optimal residence time of water in the clarifier chambers have been determined. The achieved rate of the upward flow in the zone of clarification in the boundary conditions was 25 m/h. The data obtained was taken as a basis ground for designing industrial apparatuses.
Key words
suspended layer , hardness , water , mixing , chemical water softening , liming , horizontal clarifier
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UDC 628.16.066.1:628.164-92
DOI 10.35776/VST.2023.01.04
Riabchikov Boris, Panteleev Aleksei, Larionov S. Iu., Savochkin Andrei, Shilov Mikhail, Kasatochkin A. S.
Current state of the development of installations for water softening/decarbonization by liming (a review)
Summary
Chemical softening methods have been widely used in water treatment to reduce hardness and decarbonize water. The chemistry of the process has remained unchanged for the last 100 years, however, the instrumentation and some nuances of the technology are changing, i. e., the use of devices (lamellar blocks) for stabilizing flow and improving sludge settling, the use of flocculants and introduction of sludge formation centers (recirculation of activated sludge, microsand), etc. A separate method is the adoption of horizontal multi-chamber apparatus with mechanical mixing. This method provides for increasing significantly the capacity and efficiency of the apparatus. Modern ways of development of such apparatus and technologies in the Russian Federation and overseas are considered.
Key words
suspended layer , hardness , water , mixing , chemical water softening , liming , installations
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