Sirvi Autor "Vaculik, P." järgi
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Kirje Comparison of power consumption of a two-roll mill and a disc mill(2018) Smejtkova, A.; Vaculik, P.Grinding or milling is often used process, for example in the production of feed, grinding of malt in beer production, grinding of cereals on flour, etc. In order to optimize the energy intensity of the whole production process, it is necessary to know the energy consumption of individual processes. The grinding of malt influences the mashing process, the drawing-off and the boiling yield. Correct grain grinding makes the endosperm available for enzyme and physicochemical reactions during wort production. Husks affect the drawing-off process. Two-, four- or six-roll mills, in some cases a hammer mill or disc mill, are most commonly used for grinding of malt. Power consumption was monitored when light, Munich, caramel and coloring malt were grinding. A two-roll mill and a disc mill with engine speeds of 1,500 rpm and 2,800 rpm were used for grinding. The gap between the mill rollers and the mill disks was set to 0.4 mm. The fineness of the grinding was evaluated for all types of malt on all used equipment. The energy intensity of the grinding was correlated on 1.0 kg of malt and then compared.Kirje Determination of the tension limit forces of a barley malt and a malt crush in correlation with a load size(2018) Hromasova, M.; Vagova, A.; Linda, M.; Vaculik, P.This article deals with determination of selected parameters of barley malt (whole grain and crushed grain). The barley malt is besides water, hops and brewer's yeast, one of the basic ingredients necessary for the production of traditional Czech pilsner type of beer. The aim of this research is to determine limit force and internal friction angle with depending on the size of the load. The assessed malt crush was produced using a 2-roller malt mill. The 2-roller malt mill is based on the principle of grinding the material in a milling gap between two milling rollers, which is a very commonly used production of the malt crush. By determining the tension limits of the barley malt and the malt crush in correlation with the load, we can obtain very important parameters that inform us of the bulk material behavior, particularly with respect to the storage method (storage shape, height of the stored material layer, and the removal method from the storage, etc.), and to the transport (route gradient, transport speed, etc.). The determination of the tension limits has a direct link with cohesion of the bulk material and thereby contributes to establishing of the basic parameters of the bulk material, such as - the friction angle. The measurement for the angle of internal friction determination were performed on a prototype device. The principle of measurement on a mobile prototype devices is, the upper square chamber slides down the lower square chamber. Barley malt (whole grain and crushed grain) were loaded from 100 g to 5,000 g. The results of measuring were statistically analyzed with software Statistica 12.Kirje Energy consumption of milking pump controlled by frequency convertor during milking cycle(2018) Vaculik, P.; Prikry, M.; Bradna, J.; Libich, L.The article deals with selected parameters affecting the energy consumption of a vacuum pump in a milking system during the whole milking cycle in variants with and without regulation by a frequency convertor. When put into practice, the latest research of creation, control and stabilization of vacuum in milking devices allows dairy farmers to obtain a vacuum system that ensures maximum stability of milking pressure, which is a basic requirement affecting the health of dairy cows. The choice of vacuum system prioritizes in particular high performance, maximum operational reliability, minimum maintenance, long service life, environmental friendliness and economy. The vacuum pump was a Roots vacuum pump with a rotary piston which is typical for this use. Use of a frequency convertor significantly affected the efficiency of this pump for control of vacuum pressure level and pump performance by varying the rotation frequency according to the actual airflow requirement. Using this control system, only as much vacuum pressure is produced as necessary. By measurement of an experimental setup, it was found that the average power requirement of a setup with a control valve was 3.8 kW compared to 1.7 kW in the case of the variant with frequency convertor. Measurements and calculations have shown that this system is capable of saving more than 50% of electric energy.Kirje Evaluation of nutritional and physical values of pellets based on pea and lupine with added yeast in chickens fattening(2017) Chladek, L.; Plachy, V.; Vaculik, P.; Brany, P.The article is focused on the development of the new type of broiler chicken feed, based on pea (Pisum sativum L.) and blue lupine (Lupinus angustifolius L), enriched with used dried brewer´s yeast. This composition eliminates use of soybean meal (PES) that was yet a traditional component in chicken feed. The main reason for its elimination was the using of genetically modified varieties of soybean and its relatively high price around 0.5 €uro kg-1 in Czech Republic. For milling of pea or blue lupine was used vertical (hammer) mill type Taurus, supplied by company TAURUS, for drying of used brewer´s yeast had been used drier Memmert UFE 800, final dry matter of the yeast was 88%. For pellets production were used two devices, press type JGE 120-6110 and Testmer. For the determination of physical properties of manufactured pellets (the weight of 1,000 pieces, bulk density, abrasiveness and pellet durability index PDI) were used following laboratory devices, Pellet Tester Holmen NHP and Testmer 200. Experimental activities had shown that the best results were reached using pellets manufactured on base blue lupine enriched by dried brewer´s yeast (6%).Kirje The measurement of energy consumption during milling different cereals using the sieve analyses(2018) Chladek, L.; Vaculik, P.; Vagova, A.This paper deals with the measurement of energy consumption required for disintegration of different cereals depending on the desired fineness of obtained grist. The energy consumption necessary for milling was compared with the results of a sieve analysi s before and after the disintegration process. The obtained results were compared with energy expended during the disintegration of cereals and were analysed to determine the coefficients of the ratio of fineness of milling/energy consumption. They was fou nd to have good conformity. Special attention was paid to the RRSB distribution for determination of statistic average particle size and specific area of malt grist. Specific area of grist particles from different cereals was determined by calculation of t he limited area and x axis in diagrams, this effort is necessary for optimisation of the disintegration process with impact on the quality of final food.