Inclined wave-reflective visor to reduce the height of the protective wall of the "glass in а glass" tank
Authors:   Academy of State Fire Service of EMERCOM of Russia, Bui Quang Thien , Shvyrkov Sergey Alexandrovich ,   Academy of State Fire Service of EMERCOM of Russia, Vorobyev Vladimir Viktorovich ,   Academy of State Fire Service of EMERCOM of Russia, Panasevich Lyudmila Tikhonovna ,   Academy of State Fire Service of EMERCOM of Russia
Published: December 2022

Introduction. The prospects for the construction of tanks with a protective wall of the "glass in a glass" type are due to the possibility of their use with increased safety requirements, in particular, when designing near residential areas or water areas. However, previous studies on the retention of fluid flow by a protective wall during the destruction of the internal reservoir have shown that in order to completely retain it, the wall height must be at least 10 % higher than the original liquid level in this tank. It is obvious that the construction of such high protective walls is economically impractical, while conditions can be created for the formation of zones of explosive concentrations both in its inter-wall space and behind the protective wall. In this regard, studies on an effective way to reduce the height by protecting the wall at the maximum level of filling the internal tank with a flammable liquid are relevant. In particular, it is proposed to consider the possibility of arranging on the protective wall an inclined wave-reflective visor facing the wall of the main tank. Goals and objectives. Experimentally prove the possibility of reducing the height of the protective wall of tanks with a protective wall of the "glass in a glass" type by arranging inclined wave-reflective visor on it. Obtain an empirical formula for finding the minimum height of the protective wall depending on the geometric parameters of the main tank, the interwall distance and the outbound length of the wave-reflecting visor. Methods. In the process of research, the methods of similarity theory and hydraulic laboratory modeling, physical experiment, observation, comparison, finding an empirical dependence based on mathematical processing of experimental data, description, generalization were used. Results and their discussion. It has been experimentally proven that the arrangement on the protective wall of inclined wave-reflective visor is an effective method aimed at reducing the height of the protective wall to or below the maximum level of flammable liquid in the main tank. An empirical dependence is obtained to find the optimal ratio between the outbound length of the wave-reflective visor and the inter-wall distance for the main tanks with a protective wall of the "glass in a glass" type, the nominal volume from 700 to 30000 m3. Conclusion. The proposed method of reducing the height of the protective wall and empirical dependence can be the basis for the development of the relevant provisions of the regulatory document on ensuring fire safety of tanks with a protective wall of the "glass in a glass" type, as well as used by design organizations to find optimal solutions for the design and placement of the types of tanks in question at production facilities. Keywords: "glass in a glass" tank, destruction, protective wall, inclined wave-reflective visor, laboratory modeling.