Experimental determination of the wear resistance of devices used for cutting the stalks of agricultural plants

The paper presents researches on the wear resistance of the blades integrated in the combine cutter for the harvesting of agricultural plants. The wear of the combine cutters causes production losses at harvesting both during operation and stopping machines to change the blades. Experimental determination of wear was made for blades on cutting attachment of three types of combines studied. The parameters determined in the wear study were the hardness, mass and roughness of both the new blades and the blades used for 100 hours of harvest operation. The analysis of the data on the degree of wear of the blades both quantitatively by determining the mass and qualitatively by studying the roughness of the used surfaces under identical conditions of operation, presents differential losses for the three combines that correlate with the blade hardness

Research on the influence of geometry of cutting device on harvesters during the cutting process

The paper presents a study of the influence of the constructive parameters of the blades on the cutting machines from the harvesters during the cutting process.The research focuses on the angle of sharpening of the cutting edges of the blades and the angle of inclination of the stalk during the cutting process. The blades used in the experiment have smooth and jagged cutting edges with a usual angle of 20° and modified angles of 10° and 15°. The tests were carried out using maize stalks (Zea mays) with tilt angles of 45° and 90°. The diagrams of variation of force, displacement and mechanical work during the cutting of maize stalks are presented and discussed

Studies on the Physical Changes in Corn Seeds during Hybrid Drying (Convection and Microwave)

Hybrid seed drying technology, based on convection and microwave drying, is a modern method, and the research on the physical changes in cereal seed resulting from hybrid drying is still in its infancy. The aim of the present paper is to study the uniformity of the drying process by examining the physical changes occurring in corn seeds. An innovative drying equipment, combining convective and microwave drying, was used to dry corn seeds (variety DKC5068). The convective drying was performed during the pneumatic transport of the seeds, using hot air at a maximum temperature of 50 °C; the microwave-based drying was performed using 2.45 GHz microwaves. Thus, the seeds were volumetrically heated at a temperature which does not exceed 44 °C. The physical changes in corn seeds were measured in terms of moisture, volume, cracking and color. The results regarding the moisture and volume changes in the seeds during the drying process proved that moist seeds are more homogeneous than dry seeds. The change in volume also changed the stiffness of the seeds, which showed greater homogeneity after drying compared to wet seeds. Hybrid drying led to an average shrinkage of 8.76% compared with the original seed volume, while the percentage of seeds showing cracks after drying increased by 22%. Generally, the drying process also led to color changes, but in the case of hybrid drying the results were inconclusive. Hybrid drying of corn seeds requires a shorter time and does not significantly influence physical characteristics, compared to other drying technologies

Researches regarding the effect of air flow rate for the recycling of pesticides administered with spraying machine TARAL 200 PITON TURBE-ER

The growth technologies for orchards and vineyards include a large number of treatments for disease and pest control. Without these treatments the production can be reduced by up to 35% or even totally compromised. The pesticides used for performing phytosanitary treatments are toxic substances that can pollute air, water and soil. In addition to their effect on diseases and pests, the pesticides reaching the soil extend their action over microorganisms, leading to quantitative and qualitative changes in both the edaphical population structure and the physiological activities. In the same time the pesticides fallen on the ground can be transferred, without undergoing significant alterations, into plants, fruits, animals and finally humans, causing various diseases. Pest and disease control using phytosanitary treatments is performed by the means of specialized machines, specially designed for this purpose. The treatments are effective when the size of the dispersed droplets is in the range of tens of micrometers, in order to cover as much of the surface of the leaf system as possible. The pneumatic transportation of the droplets is accompanied by the drift phenomenon, which causes a significant amount of toxic substances to land on the soil. One solution to counteract the effect of drift is to recycle the substance that is not retained by plants. Considering this principle a recycling equipment for vineyards was designed and built; the device prevents soil pollution with the substance which is not retained on the surface of the vineyard leaves. The spraying machine was equipped with air entrainment nozzles, which prevent droplets drift due to the fact that large droplets, filled with air bubbles, are transported towards the leaves. The droplets then break easily when coming into contact with the leaves, thus leading to a better covering of the surface. During the experimental tests the effect of the air flow rate over the recycling process was studied; the TARAL 200 PITON TURBO-ER spraying machine, equipped with an axial fan, was used

Heat conductivity of some food products: theoretical models and practical measurements

Thermo-physical properties are necessary for the design and prediction of heat transfer operation during handling, processing, canning, and distribution of foods. Thermal conductivity is defined as the ability of a material to conduct heat. There are steady-state and transient-state methods for measurement of thermal conductivity. The most commonly used transient methods are the thermal conductivity probe method, transient hot wire method, modified Fitch method, point heat source method, and comparative method. In this paper the modified Fitch method was used in order to measure thermal conductivity; the results were compared with the one predicted by some heat conductivity models: series model, parallel model, the weighted geometric mean method. Experimental tests and calculations were applied to the following food items: dry salami (salam uscat CrisTim); Transylvanian salami (salam ardelenesc); rustic sausage (parizer ţărănesc Caroli). The experimental tests were performed immediately after the products were purchased and then repeated after they were stored for one week, at 6°C. The results show that the series model adequately describes the heat conductivity for dry salami and rustic sausage, while the weighted geometric mean model is more appropriate Transylvanian salami, which has the lowest water content and the highest fat content

Research on the operation of an innovative equipment hybrid drying

The study of the operating parameters of an innovative equipment hybrid drying for cereal seeds is important for drying technology. An optimal operation of the hybrid dryer model requires the monitoring of essential technological parameters such as the velocity, temperature and humidity of the drying agent at the entrance to the dryer, as well as the temperature plus humidity of the drying agent at its exit. The energy consumption of the hybrid drying equipment is also monitored. Equipping the hybrid dryer with sensors to track these technological parameters is important, and knowing the accuracy of their measurement both in stationary and non-stationary regimes, leads to the evaluation of the degree of variability of the acquired numerical data. An important role in the evaluation of the technological parameters of the installation is also given by the mounting position of the sensors in the hybrid drying installation. The innovative equipment hybrid drying has both a convective pre-drying component and a final drying component through high frequency currents (microwaves). In the convective drying component, the cold air is heated in a heating battery with electrical resistances to a maximum of 44.9°C at an average dryer air inlet velocity of 16.54 m/s. In the final part of the drying plant, after passing through the microwave component, the maximum temperature reaches 39.3°C. The average energy consumed in idle operation of the hybrid dryer is 1.52 kWh

Research on the physical changes of cereal seeds dried in the innovative equipment hybrid drying

Hybrid drying of cereal seeds is a modern drying method. Over time, more research has been carried out in the field of grain drying, moving from convective drying as the commonly used method, to hybrid drying that combines the convective phenomenon with that of thermal conduction or radiation. Current technology offers the possibility of using hybrid methods of drying cereal seeds, which have the advantage of lower energy consumption and shorter drying time compared to the convective drying method. The paper proposes the analysis of the physical changes that occur after the hybrid drying of cereal seeds. The research was carried out by drying cereal seeds on an innovative hybrid drying facility that uses both convection and microwaves. In this sense, the physical changes that occur in corn seeds were studied, through determinations of humidity, changes in color, dimension, as well as changes related to the mechanical resistance of the seeds. The maximum drying temperatures inside the dryer were between 48 and 50 °C, obtained at a maximum microwave power of 2400 W, and a drying time of 3 seconds

Influence of the wetting process in the conventional system on the qualitative indices of wheat for milling

The wheat conditioning determines a series of transformations of the mechano-structural and biochemical properties of the grains. Proper wetting of the wheat grain on the outside succeeds in the peeling process in removing the upper layers of its coating without water entering the endosperm, so that in the end high quality flours will be obtained. In this study, two influencing factors were followed: the temperature in the grain mass and the rest time of grains after wetting, finally obtaining a multifactorial experience with 72 experimental variants. The experiments, performed in the present paper, revealed a close connection between the rest time of grains and their humidity after the hydrothermal treatment. Also, the three temperature ranges (10°C - 15°C, 15°C - 20°C and 20°C - 25°C) of the cereal mass for which the study was performed, had a direct influence on the water speed penetration from the outside of the grains to the inside. By establishing individually, the optimal conditioning recipe for each batch of wheat with different characteristics, the wetting period is significantly reduced in the technological process of preparing wheat grains for milling

The improvement of a traction model for agricultural tire–soil interaction

The goodness-of-fit analysis performed over the results provided by a model presented in a previous paper proved that the theoretical data were very well correlated with the experimental data with regard to the traction force (with Pearson coefficient r2 over 0.9); however, the model was less accurate in predicting traction efficiency, with r2 = 0.203. In order improve the model and obtain a better fit between the theoretical and experimental data (especially for the traction efficiency), the model was updated and modified by taking into account the geometry of the tire cross section, which was considered to be a deformable ellipse. Due to the deformable cross section, the minor axis of the tire–ground contact super ellipse decreased compared with the previous model (from 0.367 m to 0.222 m), while the major axis increased (from 0.530 m to 0.534 m). As a result, different data for the traction force and traction efficiency were obtained. The effect of the wheel travel reduction (wheel slip) over the tire–soil shear area was also investigated, and the hypothesis of a constant shear area (independent of wheel slip) provided the most accurate results. The goodness-of-fit analysis performed using the data predicted by the modified model showed that the Pearson coefficient increased significantly with regard to the traction efficiency (from 0.203 to 0.838), while it decreased by only 2.7% with regard to the data for the traction force, still preserving a high value (r2 = 0.896)

Researches regarding the optimization of the opperating process of wheat debranning for grinding

Debranning is an operation which removes parts or the entire outer layer of wheat seeds, resulting in the removal of dust particles adhering to the surface of the grain and it also clears the wheat kernels hair. The debranning operation of cereals has a large influence on the grinding work process, on the content of minerals of the flour, on germs separation and broken kernels content; for these reasons the purpose of this paper is to optimize the constructive and functional parameters of the wheat debranning installation, namely to maximize the technological work process. In order to achieve the objective of this paper, a test rig was designed and built in order to study and optimize the operating process for wheat kernels debranning; the technological line consists of: horizontal debranning machine with frusto active bodies made of Eureka type braided wire and an aspiration system. In order to study the influence of debranning operation on the quality indices of wheat seeds, several structural and functional parameters of the machine were varied and the variations of the following indices were observed: broken kernels content, ash content and the amount of peeled coating. As a result of the laboratory investigations it was found that the percentage of broken grains, the ash content and the amount of peeled coating varies with the rotor speed and the distance between the two frusto jackets. The percentage of broken grains is directly proportional to the inner jacket speed and inversely proportional to the distance between the two conical drums made of braided wire. The experimental tests showed that the percentage of ash was affected by the rotor speed and the distance between the two drums of the debranning machine. Corroborating the results regarding the content of broken grains, percentage of ash and the amount of peeledcoating led us to the conclusion that the optimum operating regime of the machine was obtained when the distance between the tapered drums was d = 10 mm, the rotor speed was 150 rev/min and 250 rev/min respectively