Research on herbaceous plants compaction in container stores using vibrating compactors

Direct-action and indirect-action vibrators for compaction of silage in container stores were built for experimental trials. Experimental results indicated that during vibrating compaction the grass layer was compacted intensely for 5-10 min. Therefore, vibrators of this type are suggested for compacting grass layers with thicknesses of 0.5-0.6 m. The determination of comparative pressure as a function of vibration frequency showed that the most effective frequency was 43.96 Hz during the direct-action vibrator compaction of grass. This relationship was determined experimentally by measuring the pressure caused by the vibrator and the effective power while compacting the grass mass in a container. The pressure increase coefficient varied over a wide range of 1.5-6.8. It was established that a centrifugal indirect-action vibrator works well to compact chopped maize (a bulk density of up to 730 kg m-3 was achieved) and works to some extent for mixtures of Caucasian goat’s rue (Galegaorientalis Lam.) and red clover (Trifoliumpratense L.). This vibrator is not suitable for compacting either pure red clover or pure Caucasian goat’s rue because the compacted densities were only 260-350 and 225-280 kg/m3, respectively. Similar studies were performed using a direct-action vibrator, and similar fodder compaction results were obtained. These vibratory silage compaction methods can be recommended for small farms. Vibrating devices are useful on herbaceous plants with large stems (e.g., maize) and are somewhat useful for mixtures including such herbaceous plants when compacting in stores

Silage production technology using grass thickening vibratory method

The article presents silage production technology using vibratory method. The objective of this research was to quantify the selected theoretical model by comparison to experimental results and to determine more reasonable calculations methods for practical issues. Based on the classical theory of mechanical oscillations a numerical analysis of silages thickening by vibrator was developed. Using the developed numerical model, the vibrator operational characteristics were obtained. Numerical and experimental investigation was performed using a direct-action vibrator to compact chopped maize. A comparison between the experimental and numerical results is presented. The results can be used to determine technical characteristics of the vibrator for silage thickening dynamics. The obtained system parameters can be used to prepare technical tasks for selection of vibratory silages thickening equipment

Investigation of physical-mechanical properties of short rotation energy plants

The plant biomass (wood, straw, energy crops) is one of the most important renewable energy sources in Lithuania and Europe. As renewable energy sources can be grown in short rotation e-nergy crops - willows and black poplars. When geometric indicators, it can be said that the willows thicker the more the fruits dry weight equal to 895,67±11,5 kg m-3. Similar results is of black pop-lar - 879,05 ± 20,93 kg m-3. Cutting the stems with screw cutter found that the largest chopped fraction accumulates on the screen when the screen hole diameter of 8 and 16 years old. The lar-gest fraction of the set when the willow stems are thicker Gl.1 - GL.2 75.77 % and 62.18 %. The evaluation of poplar, the largest fractional composition determined when the stems are thinner at the screen hole diameter of 8 mm fraction is equal to 66.72 % and 71.76 %Vytauto Didžiojo universitetasŽemės ūkio akademij

Netradicinių žolinių augalų nuėmimo ir paruošimo biokurui technologinis-techninis įvertinimas : [techninė galimybių studija]

Vytauto Didžiojo universitetasŽemės ūkio akademij

Investigation into the physical characteristics of the biofuel derived from the medium rotation energy crops

Timber is predominant resource of the biomass used for the purposes of energy production. Recently, plantations of medium rotation trees of hybrid species have been increasingly cultivated in order to produce timber to be used as a bio-fuel. Coppice plantations are cultivated on the basis of intense techniques in order to achieve accelerated wood production or any other production rela-ted to woody crops. Plant growth period of long rotation trees amounts for nearly 30–60 years, whereas that of medium rotation trees of hybrid species – only 15–20 years. Physical characteristics of chaffs of the following medium rotation energy plants have been determined: Quaking aspen (Populus Tremula), Robinia and the wild cherry tree (Pseudoacacia). The main fraction of the timber chipped using Pezzolato drum chipper has been comprised of the 8-16 mm sized particles. The ash content of medium rotation energy plants was found to be low: amounted from 1.87 % (of the wild cherry tree) to 2.4 % (of Robinia), whereas calorific values of the plants under investigation were found to be rather high: amounting for approx. 18.7 MJ/kg. These are close to calorific values of birch which is considered to be the main benchmark or refe-rence in LithuaniaVytauto Didžiojo universitetasŽemės ūkio akademij

Evaluation of energy plants chaff moisture variation in the store

Straipsnyje pateiktas ekologiškam kurui naudojamų gluosnių stiebų pjaustinio drėgnio kitimo įvertinimas laikymo metu trijose saugyklose pučiant skirtingą oro kiekį. Pateikta gluosnių stiebų pjaustinio drėgnio kitimo nustatymo metodika, pateikti bei aptarti eksperimentinių tyrimų rezultatai. Gluosnių stiebų pjaustinio laikymo ir džiovinimo natūraliu aplinkos oru saugyklose eksperimentiniams tyrimams atlikti naudoti pašarų kombaino Maral 125 smulkintuvu susmulkinti vienų metų augimo gluosnių stiebai. Nustatyta, kad stiebų pjaustinys atskirose saugyklų sekcijose džiūvo nevienodai, pasluoksniui iš apačios į viršų. Intensyviausiai džiūvo pirmojoje saugykloje sukrautas pjaustinys, ventiliuojamas pučiant pilną oro kiekį 1300±20 m3/(t h): pirmoje ir ketvirtoje sekcijose pjaustinio drėgnis sumažėjo atitinkamai iki 16,9 ir 43,0 . Mažesnis drėgnio kitimo intensyvumas buvo antrojoje saugykloje, kurioje pjaustinys buvo ventiliuojamas pučiant dvigubai mažesnį oro kiekį. Pjaustinys blogiausiai džiūvo trečioje saugykloje, kurioje nebuvo naudojama aktyvioji ventiliacija. Šioje saugykloje, visuose sluoksniuose buvo pastebėtas pjaustinio masės kaitimas bei pelėsių atsiradimas. Transportuojant bei kraunant supelijusį gluosnių pjaustinį, pelėsių sporos patenka į aplinkos orą ir gali sukelti saugyklose dirbančių žmonių kvėpavimo takų susirgimus. Taip pat deginant supelijusį kurą gaunama kenksmingų medžiagų emisija į aplinkos orą. Dėl to drėgno gluosnių stiebų pjaustinio laikyti saugyklose neventiliuojant nerekomenduojamaThe article provides evaluation of willow stems, used for ecological fuel, moisture content variation using different content of blowing air in three stores. There is methodology for willow stems carving humidity variation testing, there are results of experimental tests and there analysis too. For experimental investigation of the storage of willow stems carving and the drying in the stores by natural ambient air the forage combine Maral 125 shredder shredded one year growth of willow stems were used. It was founded that the mast carving individual storage sections dried not uniformly, substratum from the bottom to up. The carving in first store dried the most intensively, when ventilating with full blowing air quantity 1300±20 m3/(t h): humidity of chaff in the first and fourth sections decreased 19,6% and 43,0% respectively. Less intensity of the mass variation was in the second store, where the carving was ventilated blowing half the quantity of air. The carving dried worst in the third store, where active ventilation has not been used. In this store, heating of the mass and the must was observed in all layers of the carving. When transporting and handling moldy willow carving, mold spores can get into the air and can lead to respiratory diseases of people working in stores. Burning of moldy fuel leads to emissions of harmful substances into the ambient air. There fore it is not recommended to store wet willow stems without ventilationVytauto Didžiojo universitetasŽemės ūkio akademij

Profesorius habil. dr. Ramūnas Lionginas Bareišis

Vytauto Didžiojo universitetasŽemės ūkio akademij

ENGINEERING FOR RURAL DEVELOPMENT INFLUENCE OF PLANT OIL USE FOR FUEL SUPPLY AND HYDRAULIC SYSTEMS OF TRACTOR ENGINE

Abstract. Plant oils were tested instead of the mineral ones to minimize the quantity of the imported oils and nature pollution. The oils for hydraulic systems were produced from Žet-net variety rape seeds by cold pressing with the screw press. The rapeseed oil was thermally processed (in the temperature reaching 260±5 ºC, processing duration -1 hour) and catalysts were added -25 % of cupric oxide. The rapeseed oil was stabilized by adding local plant admixtures. The viscosity of rapeseed oil used in hydraulic systems of agricultural machinery was 0.917 g·cm -3 , the relative viscosity at 50 °C was 3.3 E r , the alkaline number was 0.6 mg KOH·g -1 , and the quantity of sulphur was 0.002 %. The test duration was 180 hours. The oil characteristics during the test practically remained unchanged, the hydraulic system maintained stability and worked without jerking. No oil foaming was noticed. The pressure in the hydraulic system during the tests was 12.0-12.8 MPa, oil temperature at the nominal loading did not exceed 43 ºC. The influence of rapeseed and linseed oil on high pressure hoses and polyethylene tubes used in the hydraulic system in relation to oil temperature was tested. This test lasted for 3500 hours. The largest change in the diameter of the rubber hoses was noticed when they were kept in rapeseed oil at the temperature of 75 ºC -it amounted to 18.6 % (in linseed oil -11.8 %), the surface hardness decreased by 36.4 % (in linseed oil -44.6 %). Neither kind of oil, nor the temperature had any influence on the PVC tubes. Key words: plant oil, hydraulic system, mineral oil. Introduction Plant oils made from rapeseed, sunflower, linseed and other oilseed crops can successfully replace the mineral oils used in agricultural and forestry machinery. Their use for lubrication in chain machinery and use for filling hydraulic systems of tractors is gaining larger importance in practice The studies conducted by German researches showed that during a three week period only 30 % of mineral oil from the ground surface has been decomposed, when over the same period of time about 95 % of rapeseed oil has been decomposed The goal of this paper is to evaluate the possibility of plant oil (rapeseed and linseed) use for hydraulic systems as well as to determine the potential adverse effects for rubber and plastic parts of hydraulic systems

Maize and grass mixture silage compaction with centrifugal direct-action vibrator

The efficiency of silage compaction of the chopped mass of maize and grass mixtures by means of centrifugal direct-action vibrators was experimentally evaluated in the reported study. The results indicate that the layer of grass plant chaff undergoes intensive compaction for the duration of 5-10 min. The dependences of the density variation of maize and grass plant mixture mass on compaction duration were determined. After 20 min of maize compaction, both silage layers of 510 kg m-3 density (the density of the dry matter – 143 kg m-3) were achieved. Moreover, while mixture of maize and fodder goat's rue (3:1) was compacted, a high mixture density was reached as well. After 10 min of compaction, 474 kg m-3 (166 kg m-3 DM) density was obtained. Analysis of silage quality indicates that maize mixtures (fodder goat's rue (3:1) and maize - red clover (1:1) silage), which were compacted with centrifugal direct-action vibrator, meet the requirements for the high quality silage