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Model studies of the parameters of the blade-free fan operation in the gas pump systems of steelmaking shops

Introduction

As you know, human production activity, starting with the development of minerals and ending with the production of finished products, is accompanied by dust and gas formation processes that have a negative impact on the environmental situation in industrial zones and adjacent areas of compact population, as well as on the purity of the air inside shop buildings near functioning technological equipment. Therefore, reducing the volume of emissions into the atmosphere, reaching tens of tons per day in regions with developed mining and metallurgical industries, as well as improving the working conditions of personnel by reducing the content of harmful inclusions in the workplace, are urgent tasks that require the development of new highly effective methods of evacuation of gas and dust emissions and the creation of equipment for their implementation [1].

The results of the literature review and patent search conducted indicate that in the Republic and abroad in recent years, theoretical and experimental research has been intensified related to the creation of fan systems that cause the directional movement of gas flows without the use of impellers with blades or blades attached to them. We are talking about so-called jet fans that initiate the movement of a gaseous medium by transferring the energy of air jets that flow under excessive pressure from one or more nozzles [2-5].

Relevance of the topic of master's work

An example of a successful practical implementation of a system with an inkjet device is a fan proposed in 2009 by an Englishman James Dyson and protected by several patents [6, 7]. Structurally, the specified fan is made in the form of a hollow ring with a longitudinal section similar to the profile of an aircraft wing, and also having on its inner surface a slot located along the entire length with a width of 0.5-5 mm. The air supplied by a turbine or compressor to the ring cavity is forced out at high speed through the gap and smoothly wraps around the internal aerodynamic profile, creating a rarefaction area in the center, so that the air mass is drawn in from the periphery and merges with the primary flow, forming a jet that is pushed forward and increases the volume of air at the outlet several times.

The advantages of the Dyson fan are its safety, due to the absence of external rotating elements that excite the gas flow, as well as providing more flow at the same power in comparison with mechanical fans. Its significant drawback is that in the manufacture of an annular nozzle, the cross section of which is similar to the profile of an aircraft wing, it is very difficult to withstand strict dimensional tolerances, and if even minor damage is received, the system is not subject to repair. In this regard, a fan was developed and patented, in which the nozzle part of the gas flow excitation unit is formed from a set of hollow segments having an internal surface contour similar to the shape of the longitudinal section of the hollow ring of the Dyson fan. These elements are placed in a circle on the mandrel, and their cavities are communicated by means of curved tubes with an air distribution chamber having the shape of a torus. At the same time, a flow swirler is installed at the inlet of the nozzle part, including hollow segments with an internal curved surface, fixed sequentially along the circumference on the carrier bracket and communicating their cavities with the help of tubes with a second torus-like air distribution chamber [8]. As shown by the results of previous experimental studies, the proposed fan can be used in systems for evacuation of gas and dust emissions from the working zones of steelmaking units [9, 10] and ventilation of quarries [11].

Thus, the development of highly efficient devices from the point of view of energy consumption is an extremely important urgent task in the conditions of fierce competition in the domestic and foreign markets.

Research goals and objectives

The purpose of this study is to test experimentally in laboratory conditions the efficiency of the proposed jet fan in the local gas pump system in comparison with widely used axial and radial fans.

To achieve this goal, you must solve the following tasks:

– develop a special methodology for laboratory studies of the efficiency of the blade-free fan in comparison with devices of standard designs;

– to identify criteria of comparison;

– analyze the qualitative and quantitative results of empirical research, draw conclusions and make recommendations.

Conclusions

Developments aimed at creating high-performance devices are relevant, priority and promising, since they allow us to produce a competitive product with a high added value.

The proposed system is more universal in comparison with well-known domestic and foreign analogues, since it allows for the localization and evacuation of stationary and non-stationary gas-dust formations from sources, which favorably affects the sanitary and hygienic working conditions.

It is empirically established that the proposed design of the jet fan is not inferior to axial and radial type fans in terms of efficiency in the local gas pump system and can be used when removing explosive and flammable gas-dust mixtures from the working area.

When writing this essay, the master's thesis has not yet been completed. Final completion: may 2020. The full text of the work and materials on the topic can be obtained from the author or his supervisor after the specified date.

References

  1. Боровицкий А.А., Угорова С.В., Тарасенко В.И. Современная промышленная вентиляция. Владимир: Издательство Владимирского государственного университета, 2011. – 59 с.
  2. Wahl T.L. Hydraulic performance of Coanda effect screens // Journal of Hydraulic Engineering, 2001. – Vol. 127. – Issue 6. – P. 480-488.
  3. Miozzi M., Lalli F., Romano G.F. Experimental investigation of a free-surface turbulent jet with Coanda effect // Expereriments in Fluids, 2010. – Vol. 49. – Issue l. – P. 341-353.
  4. Dragan V. A nev mathematical model for high thickness Coanda effect wall jets // Review of the Air Force Academy, 2013. – Issue 1 (23). – P. 23-28.
  5. Tony L., Wahl T.L. New testing of Coanda-effect screen capacities // This paper prepared for poster presentation at: Hydro Vision International 2013 July 23-26. Denver, CO, 2013. – 14 p.
  6. Патент 2458254 РФ, МПК F04D25/08. Вентилятор/П.Д. Гэммак, Ф. Николас, К.Д. Симмондз; заявл. 10.10.2011, опубл. 10.08.2012. Бюл. № 22.
  7. Патент 2484383 РФ, МПК F24F1/02. Вентилятор/Ф. Николас, К. Симмондз; заявл. 27.01.2013, опубл. 10.06.2013. Бюл. № 16.
  8. Патент 2630443 РФ, МПК F24F7/00, F04D25/00, F04D29/00. Узел безлопастного вентилятора для эвакуации газопылевых выбросов из промышленных агрегатов/Е.Н. Смирнов, С.П. Еронько, М.Ю. Ткачев [и др.]; заявл. 23.05.2016, опубл. 07.09.2017. Бюл. № 25.
  9. Еронько С.П., Ткачев М.Ю., Стародубцев Б.И. Моделирование газоотсоса от плавильных агрегатов с использованием безлопастных вентиляторов // Вестник Института гражданской защиты Донбасса, 2015. – Вып. 3 (3). – С. 15-19.
  10. Еронько С.П., Ткачев М.Ю., Стародубцев Б.И. Моделирование работы модернизированной системы газоотсоса кислородного конвертера с вращающимся корпусом // Вестник Донецкого национального технического университета, 2017. – № 4 (10). – С. 3-12.
  11. Еронько С.П. [и др.] Разработка конструкции и модельные исследования новой вентиляторной системы проветривания карьеров // Черная металлургия: Бюл. ин-та Черметинформация, 2018. – № 1. – С. 26-32.