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  • Author: Peciar Peter x
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Abstract

To assess the energy intensity of particulate materials mixing, it is necessary to know the state of stress in the particulate material in front of mixing elements. The theoretical background of this process results from the theory of the equilibrium limit of the particulate material, and this state may by described by Mohr’s circle theory and the Novosad model. Based on the above assumptions, it is possible to derive the pressure distribution along the blade height, but only for an infinitely long blade. A measuring system implemented on the homogenizer blade was constructed to examine the effects of the distribution of the mixed material on the mixing element along its length.

Abstract

Selective adjustment of the properties of particular material agglomeration has its inherent place in the chemical, food, but especially in the pharmaceutical, industry. The requirement to produce an agglomerate with desired particle size at a given strength is often formulated. To create the targeted product, it is necessary to know the process parameters affecting the preparation of its features. This paper deals with survey distribution characteristics and compressibility changes of an agglomerate in dependence on the duration of the granulation process through the usage of the most modern devices working with particulate materials. The investigated product will be prepared for coating granulating disc designed at the Institute of Process Engineering, Faculty of Mechanical Engineering, Slovak University of Technology in Bratislava.

Abstract

The aim of this work is to investigate a heat performance of a Multi-Layered Oscillating Heat Pipes Heat Exchanger (ML-OHPHE) for the application of heat recovery in heating, ventilation and air conditioning systems (HVAC systems). The heat exchanger is investigated experimentally under different conditions of heat loads and filling ratios. The experimental data results are compared to the data obtained from Honeywell’s UniSim® Design Suite software. In the end the NTU analysis of the ML-OHPHE is done and a value of overall heat transfer coefficient is calculated. The results of the experiments indicate that the ML-OHPHE could serve as a completely passive heat transfer device in the application of heat recovery in HVAC systems.

Abstract

This paper focuses on the characterization of the tabletting process and analysis one of the most common pharmaceutical excipients MCC Avicel PH102 by Heckel, Kawakita, Cooper-Eaton and Adams compaction equations. Experimental material was determined by measuring its parameters as particle size distribution, angle of wall friction and flow properties and for more detailed characteristics of the material particles, microscopy images of the powder before and after compressing were created.

Abstract

The paper is focused on an analysis of the most frequently used compaction equations for powdered materials such as Heckel equation, Kawakita equation and Cooper-Eaton equation. Compacting powdered materials is accompanied by various mechanisms of densification dependent on the properties of the compressed material, which makes the equation more satisfactory for a certain group of materials and for another groups less so, or makes the equation completely unsuitable. To determine the suitability of the equation experimental measurements have to be implemented on an instrumented laboratory press. Then these obtained data are approximated by the specific compaction equation and use the regression analysis to determine the parameters describing the required material or physical properties of the compressed material.

Abstract

The aim of this study was to investigate the usage of Dynamic Image Analysis for determination of size, shape and distribution of granules of microcrystalline cellulose, created by high shear granulation. A series of experiments was carried out to analyse the effect of process parameters on a created granule morphology. The amount of the granulation liquid and speed of the impeller have a significant effect on the median size granule value, the sphericity, the granule distribution width, but also on the granulation process yield.

Abstract

Calcium carbonate in the form of finely ground limestone is a material that has found its application in a wide range of industries, in the chemical, rubber, agricultural, and paper industries, is used for desulfurization of boilers and other. In civil engineering, ground limestone is used for the production of building materials, plaster and mortar mixtures, as a filler in concrete mixtures, in road construction, and as an essential component of mastic asphalt. This paper deals with examining the modification of the properties of finely ground limestone by the tumbling agglomeration method. It has been shown that the components of concrete with a round grain have a positive effect on the pumping of concrete in comparison with an elongated grain or the rough surface of crushed stone. The experiments will be carried out on a granulation plate using a variety of granulation liquid. The agglomerates and their properties were compared with untreated finely ground limestone, with a focus on detecting changes in compressibility, density and particle size. The output of this paper is a description and graphical representation of the changes in the properties of ground limestone before and after the agglomeration process.