The Relation between Burning Time and Burning Energy of HTPB - Based Composite Propellant

This paper represented a result of several visions of chemical phenomenon and several extractions and extrapolations of experimental works which included a relationship between energy related to a chemical process and the relevant time which is required to achieve this process, but it must be taken into account that those mentioned experimental works hadn’t aimed substantially to study and state this relationship neither implicitly nor explicitly, but the results of those works have been exploited for another field after being compared with the relevant thermodynamic calculations. The selected case study for this paper was the relation between the burning time of Hydroxyl terminated poly butadiene propellant ( HTPB) and the caloric value of this material. The results reflected some relationship between the burning time and the change of the system energy during the burning process.

Experimental study on examining the fire load of a small compartment

In Hungary a lot of people live in condominiums or in block of flats where fire often occurs despite of precise design and effective fire protection arrangements. This means a hazard for the people living there, for the building constructions and also for the environment. A deeper knowledge of the burning process and examining the negative effects of fire load on building constructions with scientific methods are actual questions nowadays. In order to get to know the phenomena more accurately, fire spread in a bedroom was modeled and numerical simulation was carried out, which is presented in this paper in detail. These experiences may help increasing the fire safety and preventing fires in apartments. The simulations were carried out considering the characteristics of the Hungarian architecture.

Decomposition of Crystalline Limestones during the Burning Process

The decomposition of limestone during the firing process is mainly based on the decarbonation of CaCO3. In the case of crystalline limestone, it is the decomposition of calcite crystals. In this study, different limestone properties on the course of decarbonation are studied. Therefore, the samples are determined from a geological and physicochemical point of view (geological age and origin, total porosity, limestone category, chemical analyses and insoluble residue). After thorough identification of the samples, various analyses focused on limestone and lime microstructure are performed, such as SEM image analysis or lime reactivity. For these analyses, the samples are burned at different temperatures. The decrepitation amount of limestones during burning process is determined.

Analysis of Application of Plasma Ignition in Closed Vessel Tests

This paper presents the results of a comparative investigation into the effects of the ignition method on the ballistic properties of three types of propellants: a single-base propellant, a double-base propellant and a low vulnerability (LOVA) propellant, as determined via closed vessel tests (CVT). Conventional gunpowder ignition and plasma jet ignition methods were used. The influence of the ignition method on the values of the propellant characteristics obtained in CVT was analysed. It was found that the method of ignition has an influence on the values of propellant characteristics, determined in CVT. An analysis of the experimental form functions showed that plasma ignition is not a solution to the problems inherent to the process of determining the ballistic properties of propellants in which the burning process deviates from the geometric burning law.

Design and Simulation of Pottery Kiln

Pottery industry is one of the small-scale industries in India. Most rural potters depend upontraditional pottery kilns for burning process by firewood or coconut husk. In order to producehigh quality pottery products better burning process is needed. The purpose of the project isto thermal analysis of burning process in a traditional furnace in order to achieve uniformtemperature inside the kiln and decrease the fuel consumption through better distribution of input heat. The traditional kilns are bonfire kilns, which involve open firing inshallow pit. These kilns suffer higher fuel consumption, poor ware strength andextensive breakage. Smokes produced during firing will serious health problems topottery workers and their family. There is lack of thermal studies on bonfire kilns. Accounting the demerits of traditional one is led to development of downdraught kiln. The thermal studies in performance of downdraught kiln by varying different parameters practically expensive and almost impossible. For this reason, the downdraught kiln is modeled and simulated on the computer by using the numerical method. By changing different parameter of the kiln like change in firewall height, Chimney height and roof geometry in simulation, substantial improvement in the performance of the kiln was detected. This modification is suggesting for the new design of improved pottery kiln.

Between spatial domain and grammatical meaning: The semantic content of English telic particles

The purpose of this article is to demonstrate that English spatial particles which have grammaticalised into telic aspectualisers are not devoid of the image schematic content, which motivates their use in specific contexts. Because aspectual meaning, including telicity, is compositional in nature, which means that it frequently results from the interaction of several linguistic features, it is vital to single out those predicates in which the telicity effect can be attributed solely to the particle, not any other elements of the construction. This can be implemented by adopting the scalar approach, which shows that telicity is entailed by the particle exclusively in a predicate containing an incremental theme verb. Accordingly, the incremental theme verb burn and its five telic particles (up, down, out, off and away) constitute the subject of investigation. The analysis demonstrates that each particle encodes telicity in terms of reaching the GOAL in the SOURCE-PATH-GOAL schema. Conceptual differences in encoding the termination of the burning process result from topological properties of the path construed by each particle under study.

Analisa Konveksi Paksa (Pemaksaan Udara Masuk) pada Proses Pembakaran Briket Ampas Sagu

In previous studies, the initial process of burning briquettes still takes a long time, i.e. app 15-20 minutes. In normal briquette burning, a flame comes out from the briquette hole surface. The purpose of this research is to find a solution to accelerate the burning process and then the solution to use this process easily. The main objective of this research is to examine the amount of heat generated from the briquettes burning process with the number of holes as much as 10, 12, and 14, and to measure the time of initial briquette burning until the first time the flame came out on the briquettes surface. The basic ingredients of briquettes used in this study were sago waste. The tools used are a moisture meter to measure the water content, an infrared thermometer, a temperature measuring instrument, a Stopwatch to measure time, a digital anemometer to measure the airflow speed. From this study, the results obtained indicate that the combustion process in a forced air convection conditions, resulting in the rate of heat transfer as follows: a). For using the 10 holes briquettes, the heat transfer rate is about 8.51 watts, b). In the burning of 12 holes briquettes, the resulting heat transfer rate is about 16.57 watts, c). While on the 14 holes briquettes burning, the rate of heat transfer is about 20.43 watts. When heat energy is applied to boil 5 liters of water, with a 10-hole briquette, the water boils within 23.54 minutes. When using 12 holes briquettes, the water boils in 21.31 minutes, and in the use of 14 holes briquettes, the water boils in 20.21 minutes. It is concluded that the shortest time to boil 5 liters of water is when using briquettes with 14 holes, which boils in 23.34 minutes. These results indicate that forced convection can speed up the briquette burning process and produce a fairly high temperature.

Numerical Simulation of the Burning Process in a King-Size Cigarette Based on Experimentally Derived Reaction Kinetics

Summary A comprehensive two-dimensional (2D) mathematical model has been proposed to simulate the burning process of a king-size cigarette. The characteristics of this model are including: 1) the use of kinetic models for the evaporation of water, the pyrolysis of tobacco and the oxidation of char, 2) the application of mathematical relationships between the release amounts of certain products (i.e., “tar” and CO) and different reaction variables (i.e., temperatures and oxygen concentrations), 3) the introduction of mass, heat and momentum transports, 4) the consideration of filtration effects of the cigarette filter on “tar”. These characteristics were expressed in a set of coupled equations that can be solved numerically by FLUENT. The information about the char density field, temperature field, flow velocity field, “tar” and CO density fields and the filtration efficiency could be obtained from the model. This model was validated by comparing the predictions with experimental data on puff number, the temperatures at specific locations, the filtration efficiency and the yields of “tar” and CO under different puff intensities. The calculated results show a good agreement with the experimental data. The predicted puff number was 7.3, and the experimental puff number was 6.8. The standard root mean square error (NRMSE) between the experimental and the predicted temperatures at specific locations is < 18%. The predicted filtration efficiency for “tar” was 46.1%, and the experimentally determined filtration efficiency for nicotine was 44.5%. The maximum relative deviations of the yields of “tar” and CO under different puff intensities were 8.9% and 10.6%, respectively.