Abstract:

One of the richest groups of dangerous substances in terms of their physical state are gases. For their specific properties (compression, expansion, diffusion) are an important part of engineering practice. Description of the real behavior of gaseous mixtures is difficult. Currently, the preferred explanation of the behavior of gases is through computer simulation models. But for the purposes of real gas behavior, appropriate form of presentation is demonstration experiment. A demonstration experiment is a good didactic tool in teaching technical subjects. As part of science education in environmental and technical fields, provides an opportunity for presentation and interpretation of physical and chemical processes. The paper deals with the presentation of a demonstration experiment for the purpose of gas mixtures dangerous issue. For purposes of explanation creation of homogeneous gaseous mixtures can be selected demonstration experiment called the cup-burner test. The test is also used for research purposes of flammable mixtures (combustible file) and the creation of a homogeneous diffusion flame. For experimental samples were used propane, butane and heptane in a mixture of air and oxygen. Cup-burner test is also used for demonstration purposes of gaseous mixtures fire. Traces different extinguishing gases: carbon dioxide, nitrogen, argon and nitrogen mixture and selected chemical gaseous mixture called halon alternatives (halons soft mixture with carbon dioxide or nitrogen). The result of demonstration experiments is the tracking creation of diffusion flames and their change due to changes in gas supply (real attempt to air or oxygen). While watching extinguishing gas is monitored gradually extinguish the flame. Those experiments are visualized on a CD. Implementation of the experiment are obtained limited values as a flash point of flammable gas mixtures and the minimum concentration of fire extinguishing gases, which are used for fire protection purposes.

Keywords:

Dangerous substances, demonstration experiment, burning, extinguishing.