Karol Balog

Moment of Lignocellulosic Materials Ignition Defined by Critical Mass Flow Rate

On the base of experimental observations of mass loss rate in dependance of time in isothermal condition in circulating air atmosphere was determined the moment of lignocellulosic materials ignition. Experiment was performed in an electrically heated hot-air furnace according to ISO 871 standard (Setchkin furnace) in conjunction with precision scales. Experiment was performed with ignition source. The ignition source was kanthal wire. Experiment was performed at one temperature, three positions of samples in the oven and various air-flow speeds. Pure cellulose as a model compound was impregnated by water solution of KHCO3 and (NH4)2HPO4.

A Comparison of the Behaviour of Spruce Wood and Polyolefins during the Test on the Cone Calorimeter

This article deals with comparison of the behaviour of spruce wood and polyolefins (polyethylene PE and polypropylene PP) during the test on the cone calorimeter. Samples were tested on the cone calorimeter at heat flux of 20 and 40 kW/m2. An evaluation of the behaviour of examined materials was based on the determination of the maximum and the average heat release rate, yield of carbon monoxide (CO), and relative comparison of tendency to fire propagation in a flashover phase. The tendency of materials to fire propagation in the flashover phase was evaluated based on the Pearson ́s correlation, the Spearman ́s correlation and the Kendall ́s correlation coefficient of HRR-CO and CO2-CO. Spruce wood showed better properties in comparison with PE and PP in all evaluated parameters (the maximum and the average heat release rate, the yield of CO, and also the resistance to fire propagation in the flashover phase. Additionally, spruce wood showed significantly lower sensitivity of dependence of the maximum and also the average heat release rate on external heat flux.

The Environmental Impacts of Fire-Fighting Foams

The Environmental Impacts of Fire-Fighting Foams Extinguishing foams are commonly used for extinguishing the fire of flammable liquids, whereby their insulating, choking and quenching effects are exploited. The purpose of the paper is to consider and compare the foams currently used in fire departments, regarding mainly their high extinguishing effect (capability of faster aborted burning on the large surface at low foam consumption), but also their impact on the environment in each stage of their life cycle.

Activation Energy of Pure and Impregnated Lignocellulosic Materials Obtained by Isothermal Method

On the base of experimental observations of mass loss rate in dependence of temperature in isothermal condition in circulating air atmosphere was determined the activation energy of lignocellulosic materials degradation without and with retardants. Experiment was performed in an electrically heated hot-air furnace according to ISO 871 standard (Setchkin furnace) in conjunction with precision scales. Degradation of lignocellulosic materials was performed at various temperatures and various air-flow speeds. Pure cellulose as a model compound was impregnated by water solution of KHCO3 and (NH4)2HPO4.

Ignition Temperature of Dust Layer and Dust Clouds of Wood Pellets

Abstract In the production, transport, storage and use of wood pellets forming a flammable and explosive dust. To assess the fire risk of wood pellets was determined ignition temperature of dust layers and dust clouds. We used two commercially produced pellets from wood waste and wood and studied the dependence of ignition temperature on the thickness of dust layer and also observed the ignition temperature dependence of dust clouds from the weight and pressure of air in combustion chamber.

Biodiesel Production from Waste Cooking Oil in Laboratory Scale

Biodiesel is a product from the transesterification of alcohol and vegetable oils and animal fats. Biodiesel is a greener alternative to petroleum diesel. In this study was biodiesel produce from waste sunflower cooking oil. The quality of biodiesel which was purified for two steps was evaluated and compared with sample of biodiesel produced in company MEROCO. The transesterification of waste cooking oil was successfully but biodiesel after first purification wasnt carefully washed. We recommend using plenty of water for purification, approximately 30 % of the biodiesel volume. Washing of the biodiesel was found to be necessary for a better quality biodiesel and the effects were associated with the removal of residual by-products like excess alcohol, excess catalysts, soap and glycerine.

Study of Thermal Degradation of Polymers

This article deals with measurements of selected waste polymers in the combustion process. The technology of controlled burning occupies an important position in the process of waste disposal. Therefore it is necessary to assess the behaviour of materials in the process of thermal degradation by fire characteristics. An experiment was conducted in accordance with standard STN ISO 871: 2010 Plastics. Determination of ignition temperature using a hot-air furnace. There were studied a mass loss rate of the samples in their degradation and also monitored some products of combustion.

Monitoring of Thermal Degradation of Fireproof Coating

Under the fire conditions, the resistance of cable distribution is required for a fixed period, depending on the intended use of the cable. To increase the fire resistance of cables a fireproof coating may be applied. Article deal with the behavior of the fireproof coating during elevated temperature. Concretely, the aim is monitored a coating weight change under the conditions of dynamically increasing temperature and with or without using air-flow. It is also monitored the change in weight, depending on the isothermal temperatures in dynamic air atmosphere.

Fire Risk of Halogen-Free Electrical Cable

Abstract This paper deals with the fire risk of a selected halogen-free electrical cable. The research was objected to a three-core power electric cable for a fixed installation CHKE J3x1.5 (cross section of each copper core was 1.5 mm2) with a declared class of reaction to fire B2ca, s1, d1, a1. The electrical cable was manufactured and supplied by VUKI, a. s., Slovakia. The fire risk of the electric cable was evaluated based on the heat release rate, total heat release, smoke release rate, total smoke release and effective heat of combustion. These parameters were measured using a cone calorimeter at 50 kW m−2 (specimens and cone emitter were placed horizontally during the test). The measured electrical cable showed a maximum heat release rate of nearly 150 kW m−2, a maximum average heat emission rate of almost 100 kW m−2, a total heat release of almost 130 MJ m−2, a maximum smoke release rate of almost 2.5 s−1, a total smoke release of more than 800 m2 m−2, an effective heat of combustion (cable as a whole) of nearly 9 MJ kg−1 and an effective heat of emission (polymeric parts of the cable) of 26.5 MJ kg−1.

Thermal Properties of Lignocellulose Pellets

Abstract This article deals with the characterization of biomass pellets using Differential Scanning Calorimetry. We used three types of industrially produced and commercially available pellets as samples: wood pellets containing grass, wood pellet containing bark and wood pellets without bark. Each of the samples were examined using the DSC method. Based on the measurements in atmosphere of air and nitrogen temperature, the changes caused by thermal degradation of various kinds of test fuels were observed. Subsequently, limits of exothermic processes, reaction enthalpy changes and the temperature at which exothermic reactions reached peaks were determined.