Jarosław Frączek

Impact of Selected Properties of Raw Material on Quality Features of Granular Fertilizers Obtained from Digestates and ASH Mixtures

Abstract The paper presents the results of research, the objective of which was to determine the impact of particle size distribution and density of digestates and ash on density and tensile strength of granular fertilizer obtained from mixtures of these substrates. Particle size distribution, absolute density, envelope density and porosity of substrates were determined. Granular fertilizers were made of clean substrates and their mixtures. Envelope density of the obtained granulates was within 0.81 - 1.88 g⋅cm-3. The determined compaction degree was within 3.65 - 10.12. While, the compaction index IS of granulates made of mixtures was within 0.5 - 0.55 and was lower in comparison to IS of granulates from digestates (0.6) and ash (0.76).

Present trends in research on application of artificial neural networks in agricultural engineering

Abstract The objective of the paper was to carry out a bibliometric quantitative analysis of publications concerning the application of artificial neural networks in the research area - agriculture and a bibliometric quantitative analysis and subject analysis with regard to agricultural engineering. A number of scientific publications devoted to the ANN found in the data base of the Web of Science - in documents published to 2015 was a basis for the quantitative analysis. Research on the use of artificial neural networks in the research area - agriculture is extending systematically. Moreover, a rapidly growing number of citations prove a continuous increase in the scientists’ interest in possibilities of the ANN applications. The quantitative analysis of scientific publications in 5 selected scientific journals and thematically related to agricultural engineering (indexed in the Web of Science) allowed a statement that 236 scientific articles from 1996- 2015 were related to the ANN application. The biggest number of publications was reported in Computers and Electronics in Agriculture - 118 articles. In 2011-2015 there was a growing trend in dynamics of publishing of scientific papers devoted to the ANN application to agricultural engineering. Thus, we may assume that the research related to application of the artificial neural networks to agricultural engineering will be continued and their scope and number will be still growing. The thematic analysis of the most often quoted publications from 2011-2015 in the journal Computers and Electronics in Agriculture, proved that they concern both the issues related to the classification problem as well as to modelling processes and systems. We should suppose that the subjects related to modelling of drying processes and application of neural networks for image analysis will grow dynamically in the following years.

Application of artificial neural networks in modelling the contact area of grain seeds

Abstract The objective of the research was to create a model which defines the relation between a fundamental contact area of a seed and the pressure force, water content in a seed and its geometrical dimensions with application of artificial neural networks (SSN). Computer program Statistica Neural Networks v. 6.0. was used for formation of a neural model. Tests were carried out on Roma wheat seed and Dańkowskie Złote rye with six various water contents: 0.11 0.15 0.19 0.23 0.28 0.33 (kg·kg-1 dry mass). Caryopses were loaded with eight values of compression force - from 41 N to 230 N. Multiplicity of iterations was 5. Seed material was moistened to obtain a specific water content. Each seed was loaded with compression force with respectively growing values: 41N, 68N, 95N, 122N, 149N, 176N, 203N and 230N. A four-layer network of Perceptron type with 10 neurons in the first and 8 neurons in the second hidden layer was selected as a model which the best defines the contact area of grain seeds loaded with axial force at various moisture levels. This network has 4 inputs (water content, pressure force, thickness and length of caryopses) and one output (elementary contact area of rye and wheat seeds). Comparison of the neural model with empirical formulas obtained from nonlinear estimation proved a considerable higher precision of the first one.

Analysis of Impact Of Biomass Added to RDF Oversize Fraction on Properties of Briquettes

Abstract The impact of biomass addition to the RDF oversize fraction on quality parameters obtained from this blend of briquettes produced under semi-industrial conditions was analysed. For the purposes related to the experiment four RDF mixtures with fragmented biomass of common willow Salix viminalis L., differing only with percentage participation of base elements, were prepared. The briquetting process was performed with the use of a semi-industrial briquetting machine at the determined compaction pressure of 47 MPa and a diameter of a sleeve (and a briquette at the same time) of 50 mm. Selected quality parameters of produced briquettes were determined, i.e. density, mechanical strength DU and compression strength. The best parameters were obtained for briquettes produced from the blend with a 50% share of willow (ρ=843.9 kg · m-3, DU=86.1%, Rc=0.46 MPa). The lowest parameters were in case of briquettes without biomass addition. Statistical analysis of research results indicates that biomass additions to RDF significantly affect the improvement of quality parameters of the obtained briquettes.

Agglomeration of Ash-Based Fertilizer Mixtures from Biomass Combustion and Digestate

The production of fertilizers based on high quality waste materials is a highly important problem in environmental protection, mainly due to the protection of natural mineral resources. In addition, the combination of organic and mineral raw materials makes these fertilizers innovative in the fertilizer economy. As the research material unique mixtures of mineral and organic substances mixture were used. The main components were ash from biomass combustion power plant in the Polaniec and the digestate from a biogas plant located in Piekoszow. Sulfur and phosphorite were used as components to enhance the fertilizer value of the tested prototype blends (variant A). There were also blends supplemented with urea (variant B) to add nitrogen to composition. During the tests the energy consumption of the granulation process was determined and the quality of the obtained granules was determined by specifying envelope density, bulk density and mechanical durability.

Conceptual Design of the RDF Granulation Line

The paper presents a concept of a technological line for the production of granulated fuel from RDF. The main assumption of the line is the complexity of processing a raw RDF with very variable input parameters (morphological and granulometric composition, proportion and type of impurities as well as variable moisture content) to a pellet with high quality parameters (specific density, mechanical durability). Based on an analysis of the raw material characteristics and preliminary research on the RDF granulation process, design guidelines and assumptions were proposed. This allowed to develop a block diagram including all technological operations which must be used to process raw material. For each operation a technical solution was proposed which best fulfills the stated assumptions. A vacuum transport system of raw material has been proposed to reduce the amount of fly dust generated during the production process. This system is equipped with a central filter from which the dust is driven for re-granulation. Such system, reduces production of waste byproducts. As the pelletizing unit, a developed by the authors pelletizer with modified dye was proposed. Thanks to this solution, the granulation process will proceed in the temperature about 100 °C. Beside recommended moisture content and fineness of the raw material, high temperature helps ensure the predetermined quality of pellets.

Analysis of MSW Potential in Terms of Processing into Granulated Fuels for Power Generation

Due to its morphological composition which includes mostly combustible material (plastics, paper, textiles, etc.), municipal solid waste is potentially a valuable raw material for use in power generation. On the other hand, content of incombustible fraction (glass, metal, rocks, etc.) reduces its value, particularly when solid municipal waste must be processed into the form of granulate as in case of co-combustion with coal in pulverized-fuel or fluidized-bed boilers. The process of granulation reduces also the costs of logistics processes such as transport, storage and handling. That is why the research carried out in the framework of “EkoRDF—an innovative manufacturing technology of alternative fuel from municipal waste for power and heating plants—a key component of the Polish waste management system” financed by Polish Centre for Research and Development (GEKON Programme) aimed at determining the MSW potential not only in terms of use in power generation, but mainly from the point of view of technologies of converting the waste into granulated fuels for power generation units. The test material comprised oversize and undersize fractions of municipal solid waste obtained from four sources (sorting plants). The morphological and grain-size analyses were carried out, and the parameters important from the point of view of power generation were determined (moisture content, calorific value, volatile matter content, ash content). The impact of those parameters on key stages of RDF production from waste (drying, comminution and granulation) were analysed. The analysis led to determination of acceptable raw material parameters for use in production of fuel granulates dedicated to burning in power generation units.

Methodological Aspects of Conceptual Design of an Agricultural Machine by The Case of a Tunnel Spraying Machine

Abstract The article presents the procedure of determination of a structural form of an agricultural machine which encompasses methodological aspects of design related to the division of the basic objective function into member functions, multi-variant solutions and synthesis of astructural form (a virtual prototype of an agricultural machine). The suggested course of proceeding was presented by the case of a design of a tunnel spraying machine. This example reflects well and includes the specificity of the design object in the form of an agricultural machine with specific technical and agro-technical requirements. Attention was paid to the aspects related to methodology of selection of fractional solutions based on previously defined criteria.

Analysis of Mechanical Dewatering of Digestate

Abstract Technology of processing of agricultural raw material and production residues from agri-food industry often requires their dewatering. Digestate is one of such materials i.e. the mass remaining after the bio-gasification process, which has great hydration (above 85%). The objective of the research was to know the impact of dewatering on the change of water content in digestate from biogas in Piekoszów. A mechanical dewatering process was carried out and reflected the conditions of operation of screw presses for dewatering of plant raw materials, whose screen internal diameter is 160 mm. Knowing the impact of pressure on the dynamics of raw material moisture decrease will allow modelling of the operation of industrial devices with similar operation parameters. Thus, a research on the dewatering process with the use of pressure within 0.58-2.91 MPa and slotted screens with meshes size of 0.1; 0.2 and 0.3 mm were carried out. The analysis of the obtained results indicates that an effective process of dewatering of the investigated digestate takes place at the working pressure to 1.74 MPa regardless the applied screen. Further increase of pressure does not cause a significant decrease of moisture in the investigated material.