Kažimírová V., Opáth R. (2016): Biomass combustion emissions. Res. Agr. Eng., 62 (Special Issue): S61-S65.The paper deals with gaseous emissions generated in biomass combustion in water boilers. It provides results of analyses of gaseous emissions and boiler efficiency in combustion of branches of apple trees from spring pruning, spruce cuttings and corn cobs obtained from kernel harvest. Measurements were done in laboratory conditions. Average CO emission values observed in combustion were from 334.7 to 650.18 mg/m 3 and average NO x emission values were low, between 50.1 and 157.2 mg/m 3 . Boiler efficiency in applewood combustion was lower -this was caused by its higher moisture.

Kažimírová V., Brestovi T., Opáth R., 2013. Selected properties of agricultural biomass. Res. Agr. Eng., 59 (Special Issue): S60-S64.Th e presented contribution deals with the quantifi cation of moisture, combustible matter content, ash content and higher heating value of the selected types of biomass used for the heat production by direct combustion. Th e moisture, combustible matter, and ash contents were determined by gravimetric analysis in accordance with the established standards. Th e average moisture of the materials examined varied from 4.35 to 9.17%; the combustible matter content in the original samples ranged from 79.46 to 93.51%; the ash content ranged from 2.14 to 11.28%. Higher heating values of the examined types of biomass varied from 14,996 to 17,641 kJ/kg. Th e main contribution of the thesis is the acquisition of values usable in subsequent theoretical and practical eff orts to increase the effi ciency of the heat production by direct combustion of biomass. Th e results are useable in biomass boiler design and in identifying suitable conditions for combustion, including the service parameters of biomass boilers.Keywords: gravimetry; dry mass; combustible matter; ash; higher heating value Combustion is one of the possible biomass uses, resulting in the production of heat utilisable for the household heating, heating of industrial and agricultural structures, and as processing heat. Th e products of combustion are combustion gases, solid combustion products, and heat.Th e goal of this paper is to determine the proportions of combustible matter and ash in the dry mass and the higher heating value of several materials produced in agriculture and landscape design that could be used as biofuels utilised in energy production by their direct combustion.Th e dry mass of solid fuels consists of ash and combustible matter. Th e energy content of a fuel is not characterised by the content of combustible matter in that fuel because each fuel has a diff erent higher heating value depending on its chemical composition. Th e amount of ash produced by combustion of a certain type of fuel can be estimated by means of the known composition of the dry mass of this fuel. MATERIAL AND METHODSFuel samples that were subjected to analysis (wheat screenings, hay, cane, Japanese knotweed, and poppy screenings) belong to a wide group of the agricultural waste biomass and biomass obtained from the landscape maintenance. Th e other examined sample was wheat not used for feeding purposes.Measuring of moisture and percentages of combustible matter, and ash. A muffl e furnace Nabetherm L9/11 /SW (Nabertherm GmbH, Lilienthal, Germany) ( Fig. 1) with the heating device Vol. 59, 2013 (Special Issue): S60-S64 Res. Agr. Eng.

The proposed research paper analyses power consumption in grinding rolls of a flour mill. The observed mill has 15 grinding passages. The hourly efficiency of grinding roll on the first passage is 3,006.72 kg/h. The specific power consumption of individual grinding rolls ranges from 4.955 to 24.26 kWh/t. The thesis also contains results of research of grinding effects on grist. The greatest effect on grist was observed on the first grinding passage, where particle size after grinding was only 12% of the original grain size, as determined by sieve analysis. On the second through fifth passage, it was 85 to 96% (or 78 to 85% with shelling) of the original size. It was discovered during scouring that, in some cases, the sieve size of particles after grinding increased from 101 to 104% of the original size. This is due to shear force causing trituration of grist.