Henryk Otwinowski

Modeling the Multi-Stage Classification in a Fluidized Bed Jet Mill

The research and modeling the classification effects in a fluidized bed opposed jet mill are presented. Particle distribution is the result of the interaction between two stages of classification in this mill: gravity classification above the bed, and centrifugal classification in a mill classifier. The objective of the study is to develop a model of multi-stage classification and apply in to the process in question. The universal algorithm of constructing the matrix model of arbitrary complex classification circuit is proposed and the example of its application to modeling the classification in the mill is presented. The experimental identification of the model parameters was carried out.

Oxy-fuel Combustion of Wheat Straw Pellets in a Lab-Scale Fluidized Bed Combustor

This paper presents an experimental study on agro biomass pellets combustion in a circulating fluidized bed (CFB) under three oxy-fuel conditions (21%O2/79%CO2, 30%O2/70%CO2 and 40%O2/60%CO2) and air–fuel condition. The combustion of wheat straw pellets was conducted at a temperature of 850 °C in a 12 kW lab-scale CFB combustor. The main objective of this study was to investigate the combustion behaviour of wheat straw, in terms of particle temperature profiles, ignition time, volatiles combustion time and burnout time. The results of the tests show that the composition of the oxidizing atmosphere highly influences the combustion process of biomass fuels. Replacing N2 in the combustion environment by CO2 caused slight delay in the combustion of wheat straw pellets. The combustion process in O2/CO2 mixtures at 30 and 40% O2 is faster and shorter than that at lower O2 concentrations.

Use of Solar Installations as a Way to Reduce Low Emissions

The paper presents the application of solar heating installation as an element contributing to the production of heat in a traditional coal heating plant. To reduce emissions from furnaces of individual households, it is advisable to opt out of this type of heating and, where possible, to connect to a central heating system fed from a heating plant. In this way, the fragmented heat generation, where control of the combustion process is ineffective, will be replaced by central heat generation where the local community’s nuisance is limited and the combustion process is controlled. In addition, the use of solar installations reduces the amount of coal burned and thus reduces harmful emissions. Renewable energy sources are characterized by the randomness of their use. It is often the case that potential uses (wind, sun) do not coincide with the time of energy demand. A solar installation working as a auxiliary element of coal boilers seems to be a good way to address the above mentioned deficiency of renewable energy.