Vliv počáteční teploty a tlaku na výbuchové parametry prachovzdušných směsí

Abstract

Dissertation deals with the determination of parameters of explosion (lower explosion limit, the maximum explosion pressure and maximum rate of explosion pressure rise) dust-air mixtures in non-standard initial conditions, which are within the scope of this work meant to increase the initial temperature and altered the initial pressure (vacuum and overpressure). Issue of the determination of explosive parameters address by a group of standards CSN EN 14 034 - Determination of explosion characteristics of dust clouds. Procedures based on these standards define the procedure to follow when determining the explosion characteristics of dust under standard laboratory conditions (initial temperature ti = 20 ° C and an initial pressure pi = 1 bar). In practice, however, flammable dust can occur in an environment that does not correspond to standard laboratory conditions. It may be an elevated temperature e.g. during drying or other technological processes or altered pressure conditions, whether it is a reduced pressure (vacuum) or elevated pressure (overpressure), which may occur for example by pneumatic transport. Dissertation is focused on draft calculation tool on the basis of which can be estimated explosion characteristics of dust clouds at elevated temperatures or altered the initial pressure. These parameters can serve as information for the experimental validation of explosion characteristics of dust or as additional information in the design of explosion safety measures so that they function reliably and responded well to dust explosion parameters affected by the initial conditions. As part of this work is also elaborate the methodology for establishing explosion characteristics of dust under elevated temperature and altered pressure in the test device with the designation "Explosion autoclave VA - 250".