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

The further text is accessible on a paid subscription.
For authorisation enter the login/password.
Or subscribe

REFERENCES

1. Braginskii L. N., Begachev V. I., Barabash V. M. Peremeshivanie v zhidkilh sredakh [Mixing in liquid environment. Leningrad, Khimiia Publ., 1984, 336 p.].
2. Prokudina E. V., Tropnikov D. L., Karataeva A. V., Shukshina O. V. [Neutralization of technical sulfuric acid with natural limestone at Sviatogor JSC]. Gornyi Informatsionno-Analiticheskii Biulleten’ (Scientific and Technical Journal), 2016, no. 8, pp. 340–345. (In Russian).
3. Abiev R. Sh., Grigor’eva A. N. [Pat. 2683078, RF. MPC B01F 7/18, B01F 7/26. Mixing device]. Izobreteniia. Poleznye Modeli, 2019, no. 9. (In Russian).
4. Lin F. Y., Shao S. EKATO handbook of mixing technology. Schopfheim: Wear, 1991, v. 143, pp. 231–240. Strenk F. Peremeshivanie i apparaty s meshalkami [Mixing and apparatus with mixers. Translated from Polish under the editorship of Shchupliak L. E. Leningrad, Khimiia Publ., 1975, 384 p.].
5. Planovskii A. N., Nikolaev P. I. Protsessy i apparaty khimicheskoi i neftekhimicheskoi tekhnologii [Processes and apparatus of chemical and petroleum technology. Moscow, Khimiia Publ., 1987, 496 p.].
6. Dytnerskii Iu. I. Protsessy i apparaty khimicheskoi tekhnologii: uchebnik dlia vuzov [Processes and apparatus of chemical technology: a textbook for universities. Moscow, Khimiia Publ., 2002, 400 p.].
7. Zwietering Т. N. Suspending of solid particles in liquid by agitators. Chemical Engineering Science, 1958, v. 8, is. 3–4, pp. 244–253.
8. Nur Syafiqah Janurin, Choe Earn Choong, Zauyah Zamzam, Shaliza Ibrahim. 16th European Conference on Mixing – Mixing 16 «Suspension Characteristics of Fine Particles at High Loadings in Flat and Dished Base Tanks», Toulouse, France, 2016.
9. Baldi G., Conti R., Alaria E. Complete suspension of particles in mechanically agitated vessels. Chemical Engineering Science, 1978, no. 33, pp. 21–25.
10. Ayranci I., Kresta S. M. Critical analysis of Zwietering correlation for solids suspension in stirred tanks. Chemical Engineering Research and Design, 2014, no. 92, pp. 413–422.
11. Rieger Ditl. Suspension of solid particles. Chemical Engineering Science, 1994, no. 49, pp. 2219–2227. Grigor’eva A. N., Abiev R. Sh. [Influence of the geometry of the mixing device on the diameter of air bubbles during mixing in the gas-liquid system]. Khimicheskaia Promyshlennost’ Segodnia, 2019, no. 5, pp. 18–22. (In Russian).
12. Grigor’eva A. N., Abiev R. Sh. [Comparative analysis of the influence of the geometric shape of the impellers of mixing devices on the suspending efficiency in the liquid – solid system]. Izvestiia SPbGTI (TU), 2018, no. 45, pp. 94–97. (In Russian).