Jarosław Frączek, Karolina Słomka-Polonis, Krzysztof Mudryk, Marek Wróbel and Krzysztof Dziedzic
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.
Krzysztof Mudryk, Jarosław Frączek, Marcin Jewiarz, Marek Wróbel and Krzysztof Dziedzic
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.
Sławomir Kurpaska, Hubert Latała and Dariusz Baran
The paper presents the results of analysis which enable determination of the value of the pressure losses coefficients which occurred during air suction and flow through a perforated pipe. Knowledge on them is indispensable for determination of regularity of air suction along the considered pipe. Exiting the basic energy equation, firstly a local coefficient of pressure losses was determined and then the form of the relation for its determination in the function of independent variables was found out. In the second stage, the value of pressure losses caused by mutual crossing of two streams (axial stream and stream sucked by the side surface of a pipe) was determined. Also, for this coefficient, the form of the correlation equation including power relation between the independent variables was emphasised. The calculated values of the discussed coefficients from determined forms of correlation equations are satisfactorily compliant with the calculated values from the experiments which were carried out.
In recent years systemic changes in waste management have affected searching and implementation of solutions that increase waste recovery including those intended for recycle. The article presents a predicted amount of municipal waste intended for recovery based on their selected streams. For the needs of a conceptual solution the area was determined, which was operated by the mentioned installation. The paper uses the indicators of waste accumulation: mass, volume, bulk density and irregularity of their collection in 2011-2013 for determination of the sorting plant efficiency. Elements of the installation, which should enable optimization of the waste recovery process optimization, were selected. Moreover, frames of technological efficiency of the suggested solution were defined. The aim of the paper was an attempt to select parameters of a municipal waste sorting plant with location under conditions of Stary Sącz city.
Jarosław Frączek, Sławomir Francik, Zbigniew Ślipek and Adrian Knapczyk
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.
Przemysław Kobel, Leszek Romański, Jerzy Bieniek, Przemysław Bukowski and Agnieszka Martynowicz
In order to support the designing process and selection of subassemblies of an installation, specialist application programs are created. Selected applications were compared in the paper through their use for designing hypothetical solar collector systems for a single family house with a varied number of household members. With the use of particular applications, calculations for the same input assumptions were made. Results obtained with the use of a traditional calculation method were a reference point. Applications were compared on account of the type and amount of input parameters which may be introduced, type and number of determined values and their value. Based on the obtained results usefulness and scope of use of an application were assessed.
Dissipation hypothesis of energy under cyclic loads conditions was used to characterize the behavior of berry fruit. The possibility of dissipation of energy as a result of plastic deformations (Dawidenkow hypothesis) or visco-elastic deformations (Voigt hypothesis) was considered. Tests of hysteresis of whole fruit squeezed among two rigid plates for various levels of load and with various speeds of deformation of samples for two directions of load application were conducted for verification of the usefulness of both hypotheses. The strength tests were preceded by the test of hysteresis, the mass and the geometry of fruit were determined additionally as well as conventional density and moisture was counted. A mutual relation of average values of the coefficients of elasticity EC was accepted as the measure of dissipation of energy as a result of changes in the angle of inclination of the curve in the springy return phase. Voigt hypothesis was confirmed as useful within the range of small speeds of deformation and lack of usefulness of the Dawidenkow hypothesis was proved.
A condition of obtaining compost with proper sanitary parameters is achieving the organic recycling process temperature which exceeds 7°C. The objective of the paper was to determine the temperature course in the compost tank for organic recycling of dead poultry in relation to the applied structure forming material. Wheat, oat, barley, rapeseed and corn straw were used as a structure-forming material. A measuring system was equipped with a probe with a temperature sensor with precision of ±0.15°C, transducer and data recorder. Results were prepared with the use of the analysis of variance at the level of significance of α=0.05. Statistically significant differences of the temperature value in the thermophille phase of the composting process between combinations of the experiment were indicated. In all investigated combinations of the experiment, achievement (or exceeding) the temperature value of 70°C of the compost mass was reported.
The objective of the paper was to present straw pellets production technology and to determine their production costs. The paper presents also the cost structure and economic effectiveness of pellets production. Tests were carried out in EKO-BIOMASA company which produces pellets. It is located in Biechów in Świętokrzyskie Voivodeship. Unit costs of pellets production were: 310.20 PLN ∙ t-1 for option 1, 285.40 PLN ∙ t-1 for option 2 and 278.90 PLN ∙ t-1 for option 3. The most favourable was option 3 when the pellet production was carried out on the technology line in the 3-shift system day and night. In all three variants of pellet production, the highest costs were in case of electric energy. Its participation in the cost structure in relation to the option was within 42% (option 3) and 38% (option 1). The obtained indicator of economic effectiveness for all the investigated options was higher than one.
In this study the influence of selected factors, such as duration of water sorption resulting from the process of reducing sugars elution from semi-finished products, temperature of sorbed water, frying temperature and size of the studied objects (thickness of slices), on the total fat content in dry mass of the obtained products was analyzed. The study was conducted on Innovator cultivar. The scope of the study encompassed 5, 10, 15, 20 min water sorption linked to the process of reducing sugars elution. A control study was also conducted on samples without the process of reducing sugars elution. Temperature of sorbed water was 20 and 40°C; temperature of slice frying was 140 and 180°C; the size of the studied objects, in the experiment limited by the thickness of slices, was 4 and 9 mm. Determination of the total fat content in the products was conducted using the Soxhlet method. The greatest amount of fat in dry weight was contained in the products from samples in which sugars were not eluted, when the process was conducted for a short period of time (several minutes) or when elution continued for the longest period of time, approx. 20 min. The smallest amount of fat was contained in the products from samples in which the immersion in water was conducted for 10-15 min. Thicker slices absorb smaller amounts of fat. Increase of temperature of sorbed water in the process of extracting sugars from semi-finished products results in the increase of the total fat content in dry weight of products.