Experimental determination of the rational geometrical parameters of the sprinkler frame arms and deflector on the expansion rate and stability of foam

Abstract

The results of experimental studies on determination of the effect of the deflector-type sprinkler geometric parameters on the air-mechanical foam formation process are presented in the article. A collapsible sprinkler was developed for the experiment. The elements of the collapsible sprinkler which allow creating its various configurations in a fairly wide range of geometric parameters were made from polylactide (PLA-plastic) with the help of 3D printing. The dependencies of the air-mechanical foam expansion rate and stability on the sprinkler holder length, as well as the external diameter, the taper angle and the ledges height of the sprinkler sprayer were established. The ranges of optimal values along the holder length L = 45÷55 mm and the sprayer ledges height h = 1÷3 mm of the sprinkler for generation of foam with the greatest expansion rate and stability were determined, as well as the ranges of values of these parameters at which the change in the quality characteristics does not occur (L = 90÷150 mm, h = 5÷15 mm). A decrease in the foam quality characteristics with an increase in the sprayer taper angle of the sprinkler was established. Approximate dependencies of the foam expansion rate and stability on the sprayer taper angle of the sprinkler in the range α = 30÷135° were obtained. In addition, it is determined that an increase in the sprayer external diameter in the range from 20 mm to 100 mm results in a gradual deterioration in the foam qua lity. The results of the conducted researches will allow optimizing geometrical parameters of existing designs of deflector-type sprinklers with the aim to increase their fire extinguishing efficiency.

An Overview of the Main Trends in the Creation of Biodegradable Polymer Materials

“…e industrial synthesis of high-molecular weight polylactide (100,000) is currently carried out by polymerization of lactide. Initially, an oligomer is obtained, then it is cyclized into lactide, and deep purification is carried out and polymerized with opening of the lactide ring [118][119][120].…”

“…Despite the fact that the raw materials for this polymer are much more expensive than conventional packaging materials, such as polyethylene and polystyrene, the costs at the end of the service life may be lower. Biodegradation of polylactide depends on temperature, the presence of low-molecular weight impurities, and traces of the catalyst [118][119][120][121].…”