Experimental investigations of the influence of the structural elements of sprinklers on the expansion rate of air-mechanical foam
DOI:
https://doi.org/10.33408/2519-237X.2017.1-2.167Keywords:
automatic firefighting installations, air-mechanical foam, preaeration, foam expansion rate, sprinklers, Venturi principle, deflector, fire-extinguishing efficiencyAbstract
Purpose. Differentiation of constructive foam-forming factors, namely the ejector and the sprinkler deflector, influencing the expansion rate of the obtained air-mechanical foam in automatic firefighting installations.
Methods. Conducting an experimental study of the process of formation of low expansion air-mechanical foam with sprinklers of various designs.
Findings. The design of the sprinkler ejector with a cylindrical flowing path performs a preaeration of the extinguishing agent by only 12 % less efficient than the ejector made on the Venturi principle. It was found that the mechanical disintegration of the foaming solution flow on the sprinkler deflector has the greatest effect on increasing the expansion rate of the air-mechanical foam (the expansion rate increases by an average of 158 % in various sprinkler designs in the presence of the deflector). It is determined that as the distance of the element is increased, which ensures the splitting of the jet of the foaming solution, the expansion rate of the foam is increased. Thus, when the disintegration element of the flow (the bottom of the measuring container) was installed at a distance of about 50 cm from the deflector, the expansion rate increased by an average of 161 % compared to the values obtained when this element was installed at a distance of 3-4 diameters of the deflector of the sprinkler.
Application field of research. The obtained results of experimental study can be used to improve the efficiency of firefighting with sprinklers in foam automatic firefighting installations.
Conclusions. The effectiveness of preaeration of the extinguishing agent has been confirmed. The effect of individual structural elements of modern sprinklers on the expansion rate of air-mechanical foam is established. It is determined that the greatest contribution to the increase of expansion rate is brought by the desintegration of the flow of the foaming solution on the sprinkler deflector. Consequently, by modeling the surface of the deflector, the way it is fastened and positioned, it is possible to achieve values of the foam expansion rate K = 10–15 even without the effect of preaeration. To determine the influence of the geometry of the deflector, the method of its fastening and positioning with respect to the sprinkler, additional theoretical and experimental studies are required.
References
Sprinkler Reliability. Information file. BAFSA, available at: http://www.bafsa.org.uk/pdfs/publications/9/00000109.pdf (accessed : March 07, 2017). (eng)
John R. Hall. JR. NFPA USA. U.S. Experience with sprinklers and other automatic fire extinguishing equipment [Text]. 2013. P. 81. (eng)
Razvitiye sprinklernykh pozharnykh sistem. Istoriya i tendentsii [Development of sprinkler fire systems. History and trends]. Journal «Santekhnika». 2011. No. 1. Pp. 58-61. (rus)
Sobur’ S.V. Ustanovki pozharotusheniya avtomaticheskie : uchebno-spravochnoye posobie [Automatic firefighting installations. Tutorial]. Moscow : PozhKniga, 2014. 320 p. (rus)
Pavlyukov S.Yu. Orositel’ avtomaticheskoy ustanovki pennogo pozharotusheniya s predvaritel’noy aeratsiey ognetushashchey rabochey sredy [Sprinkler of the foam automatic firefighting installations with pre-aeration of extinguishing working substance]. PhD diss. Minsk, 2016. 160 p. (rus)
National standard of the Republic of Belarus. Penoobrazovateli dlya tusheniya pozharov. Obshchie tekhnicheskie trebovaniya i metody ispytaniy [Foaming agents for firefighting. General technical requirements and test methods]. STB GOST R 50588-99. Minsk : Gosstandart Respubliki Belarus’, 1999. 18 p. (rus)
Kucher V.M., Merkulov V.A., Zhukov V.V., Kucher V.N., Ponimasov V.M. Izuchenie protsessov tusheniya plameni nefteproduktov nizkokratnymi penami [Study of the processes of extinguishing the flame of petroleum products with low expansion foams]. Pozharotusheniye : Sb. nauch. tr. Moscow : VNIIPO, 1984. Pp. 29-37. (rus)
Bezrodnyy I.F., Reutt V.Ch. Razrushenie peny na poverkhnosti goryuchey zhidkosti [Foam destruction on the surface of a combustible liquid]. Issledovaniya v oblasti obespecheniya pozharnoy bezopasnosti na predpriyatiyakh aviatsionnoy promyshlennosti. Moscow : MAI, 1983. Pp. 25-29. (rus)
Bezrodnyy I.F. Bobkov A.S. Razrushenie vozdushno-mekhanicheskoy peny v fakele plameni [Destruction of air-mechanical foam in a flame]. Pozharnaya tekhnika i tushenie pozharov : Sb. tr. Moscow : VNIIPO MVD SSSR, 1982. Pp. 70-73. (rus)
Lebedev S.Yu. Vliyanie temperatury rastvoriteley na razrushenie pen [The effect of solvent temperature on the destruction of foams]. Pozharotushenie: Sb. nauchn. tr. Moscow : VNIIPO, 1985. Pp. 51-54. (rus)
Sharovarnikov A.F Issledovanie kinetiki razrusheniya pen vodorastvorimymi smesyami [Investigation of kinetics of destruction of foams by water-soluble mixtures]. Sredstva i sposoby pozharotusheniya: Sb. tr. Moscow : VNIIPO, 1980. Pp. 8-14. (rus)
Meshman L.M., Tsarichenko S.G., Bylinkin V.A. Orositeli vodyanykh i pennykh avtomaticheskikh ustanovok pozharotusheniya [Sprinklers for water and foam automatic firefighting installations]. Moscow : VNIIPO, 2002. 315 p. (rus)
Kachanov I.V., Kulebyakin V.V., Pavlyukov S.Yu. O vliyanii predvaritel'nogo gazonasyshcheniya penoobrazuyushchego rastvora na kharakteristiki peny, generiruyemoy v avtomaticheskikh ustanovkakh pozharotusheniya [On the effect of the preliminary gas saturation of the foaming solution on the characteristics of the foam generated in automatic firefighting installations]. Vestnik Komandno-inzhenernogo instituta MChS Respubliki Belarus'. 2015. No. 2 (22). Pp. 52-61. (rus)
Karpenchuk I.V., Polevoda I.I., Kachanov I.V., Pavlyukov S.Yu., Volchek Ya.S., Palubets S.M. Orositel' s predvaritel'noy aeratsiey ognetushashchego rastvora [Sprinkler with pre-aeration of the extinguishing solution]. Pat. 10277 Resp. Belarus’, MPK (2006.01) A 62S 31/00. Zayavitel’ KII MChS. № u 20140830. Zayavl. 10.01.14. Opubl. 02.06.14. National center of the intellectual property. 2014. No. 5. 175 p. (rus)
Kamlyuk A.N. [et al.]. Eksperimental'nye issledovaniya opytnykh obraztsov vodopennogo nasadka [Experimental studies of prototypes of water-foam nozzle]. Vestnik Komandno-inzhenernogo instituta MChS Respubliki Belarus’. 2015. No. 2 (22). Pp. 61-68. (rus)
Pryamye izmereniya s mnogokratnymi nablyudeniyami. Metody obrabotki rezul'tatov nablyudeniy. Osnovnye polozheniya [Direct measurements with multiple observations. Methods for processing the results of observations. Basic provisions]. GOST 8.207–76. Enter 01.01.77. Moscow : Izd-vo standartov, 1976. 9 p. (Gosudarstvennaya sistema obespecheniya edinstva izmereniy). (rus)
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