Development of Harvesting Machines for Willow Small-Sizes Plantations in East-Central Europe

The production of plant biomass in small farms within the Central and Eastern European countries requires the application of agricultural machines adjusted to the scale of production. In the article, new machines for small-sized plantations of energy crops have been presented. Furthermore, the results of strength analysis of three-point linkage mower frame are presented by finite element method. The advantage of the proposed solutions is their simple construction, which is connected with low production cost and simple machine operation. The energy-crop harvesting machines are especially intended for small biomass producers in East-Central Europe, and the purchase of professional machines is financially inaccessible. The proposed machines are mounted in front or at the back of a typical farm tractor and the chipping units are power-take-off driven. The numerical simulation was carried out using finite element method to study the structural strength of a mower frame. All machine designs proposed by the Rzeszow University of Technology are legally protected by patents and utility models. The presented agricultural solutions have been worked out by authors and a part of them is still being developed in cooperation with biomass producers

DETERMINATION OF EFFECTIVE PROPERTIES OF FIBER-REINFORCED COMPOSITE LAMINATES

The determination of effective mechanical properties of multi-layer composite is presented in this paper. Computations based on finite element method predicting properties of inhomogeneous materials require solving huge tasks. More effective is Mori-Tanaka approach, typical for micromechanics problems. For regularly distributed fibers closed-forms for effective composite material properties are possible to derive. The results of homogenization are used in strength analysis of the composite pressure vessel

Bending Moment and Cross-Section Deformation of a Box Profile

In the process of plastic bending of thin-walled profiles, there is a significant deformation of the cross-section, which has a very significant impact on the course and effects of the shaping process construction products. In this paper, the experimental, analytical as well as numerical analyses of the box profile bending process enabled to establish the relationships determining the dependence of the cross-sectional form and bending moment on the bending curvature. The following paper discusses pure bending moment and the cross-sectional deformation of 21.5×21.5×1.8 mm and 25×25×2.5 mm square tubes made of the 6060 aluminium alloy. Satisfactory agreement of the experimental results and numerical calculations was obtained for the values of horizontal and vertical wall deflection, as well as for the experimental, calculated and numerical bending moment characteristics

Wpływ kondycjonowania osadów ściekowych popiołem ze spalania biomasy na ich charakterystykę reologiczną

This study presents the rheological properties of sewage sludge after conditioning with the application of biomass ash. The impact of sewage sludge pre-treatment on its viscosity, flow curves and thixotropy was investigated. The increase of shear stress and the decrease of viscosity were observed with the increase of shear rate. Obtained results were compared with raw sewage sludge and the sludge after modification by means of polyelectrolyte in the dosage of 1.5 g‧(kg d.m.)-1. The findings proved that samples of raw and conditioned sewage sludge had thixotropic characteristics. The correlation between moisture content and capillary suction time reduction as well as selected rheological parameters were also determined. On the basis of the obtained results it was stated that the Ostwald de Vaele model best fits the experimental data.Artykuł przedstawia wyniki badań dotyczących wpływu kondycjonowania osadów ściekowych z użyciem popiołów ze spalania biomasy na ich charakterystykę reologiczną. Zbadano lepkość oraz właściwości tiksotropowe osadów po ich kondycjonowaniu. Odnotowano wzrost naprężeń stycznych wraz ze wzrostem prędkości ścinania. Uzyskane rezultaty porównano z wynikami badań dla surowego osadu, jak i dla osadu kondycjonowanego z użyciem polielektrolitu w dawce 1,5 g(kg s.m.)-1. Stwierdzono również, że próbki kondycjonowanych osadów ściekowych wykazują właściwości tiksotropowe. Wyznaczono również zależności pomiędzy uwodnieniem, czasem ssania kapilarnego oraz wybranymi parametrami reologicznymi osadów. Na podstawie uzyskanych rezultatów stwierdzono, że najlepsze dopasowanie wykazuje model Ostwalda de Vaele

Cross-Section Deformation and Bending Moment of a Steel Square Tubular Section

When bending thin-walled profiles, significant distortion of the cross-section occurs, which has a significant impact on the course of the bending moment characteristics and on the value of allowable bending curvatures. This paper presents the results of experimental and numerical modeling of the box profile bending process, which was carried out in order to determine the dependence of the cross-sectional shape and bending moment of bending curvature. Extensive numerical calculations were used to model the process of shaping a square pipe from a circular tube and to model the bending process, especially when taking into account the effects of such a deformation path. The pure bending moment characteristics and the deformation of the cross-section were performed for a 25 × 25 × 2 mm square tube made of S235JR structural steel. The innovative approach for determining the parameters of cold bending square tubes pertained to considering the stress state in the preserved material in individual areas of their cross-section. The results of numerical modeling—after considering the history of deformation (i.e., the process of forming a square pipe from a pipe with a circular cross-section)—gave a satisfactory agreement with the results of experimental tests, both in terms of the degree of pipe wall deflection and the characteristics of the bending moment

The application of biomass ashes in sewage sludge management – a SWOT analysis

Biomass plays an important role amongst renewable energy sources and for this reason, it is sometimes called as “future fuel”. According to different statistics, the share of biomass in renewable energy production is in excess of 50% and rising. The main disadvantage of biomass combustion in power plants is the production of combustion by-products, namely fly and bottom ash. In line with the sustainable development and waste hierarchy, biomass combustion by-products should be managed in different sectors of economy. Due to the specific properties, biomass ash might be applied as an effective reagent in sewage sludge management. This article shows the SWOT analysis (strengths, weaknesses, opportunities and threats) associated with the use of biomass combustion by-products in sewage sludge treatment. The presented analysis could constitute the initial stage in implementation of new method in a big way in treatment plants

The application of biomass ashes for improvement of sewage sludge dewatering

In compliance with the requirements of the EU climate and energy package (3 × 20 %), the biomass consumption in energetic industry is systematically growing. As a consequence, a large amount of ashes is produced which requires the management in line with law and ecology. Stringent requirements concerning the chemical composition of ashes prevent the biomass ash from being used in building construction. Specific physicochemical properties of ashes allow for their application in sewage sludge treatment. This paper presents the results of conditioning using ashes from willow combustion in sewage sludge dewatering. The findings could provide a new approach on sewage sludge and biomass ashes utilization

Ecological and Economic Aspects of the Application of Sewage Sludge in Energetic Plant Plantations - A Swot Analysis

Sewage sludge management in Poland is a relatively new field of waste management called “in statu nascendi”, the standards of which have not been recognized yet. It also requires the implementation of new solutions in the field of sewage sludge. So far, the most popular method of sewage sludge utilization has been landfill disposal. In line with the restriction placed on landfill waste with a calorific value above 6 MJ/kg introduced on 1 January 2016, agricultural use and thermal methods are particularly applied. Municipal sewage sludge may be successfully used in the cultivation of energetic plant plantations. The aforementioned waste could be treated as an alternative to traditional mineral fertilizers, which in turn might successfully provide valuable nutrients for plants. This paper illustrates the SWOT analysis (Strengths, Weaknesses, Opportunities, and Threats) associated with the use of sewage sludge from Świlcza-Kamyszyn WTTP (Podkarpackie Province, Poland) for agricultural purposes. This analysis could be useful in evaluating the utility of sewage sludge in perennial plant plantations in order to determine the appropriate waste management strategies

METHOD OF FERTILIZATION OF ENERGY WILLOW PLANTATION USING SEWAGE SLUDGE

Sewage sludge deriving from biofiltrationof municipal waste abound in soil processed organic substances and mineral fertilization components which may be used for fertil-ization of energy willow plantations. In the article the potential of natural utilization of sewage sludge and the patented device for injection dosage of sludge has been pre-sented. The device enables putting into soil mineral and organic fertilizers with loose consistency and their immediate covering by soil in order to reduce unpleasant smell and limit loss of volatile components of fertilizer