Food Chilling Methods and CFD Analysis of a Refrigeration Cabinet as a Case Study

This chapter presents the most significant facts about food chilling. For food chilling, the chilling medium in mechanically cooled chillers may be air, water or another secondary cooling agent (slurry ice), or metal surfaces (heat exchangers). Ice chilling is also presented. CFD simulation is applied to a vertical display cabinet with four shelves. In order to evaluate the temperature gradient, the following stages are taken into account: preprocessing—geometry set-up and design of the discretization scheme; processing—introduction of the boundary conditions and calculation; and post-processing—visualization of the velocity and temperature fields

Equipments for reducing soil pollution with pesticides for pest and disease control in vineyards

Phytosanitary treatments are used for pest and disease control in vineyards; specialized machines and equipments are used for performing the treatments. Most of the equipments use the principle of hydraulic or/and pneumatic spraying of chemical solutions. In the process of spaying a certain part of the solution (especially at the first treatments) is lost and flows to the ground, thus leading to the chemical pollution of soil. In order to diminish this effect a special equipment was designed and constructed; its aim is to collect the droplets that do not reach the leaves. The equipment comprises two vertical panels, which are retractable and can be positioned on either side of the vineyard rows; the panels collect the chemical solution that was not retained by the plantation foliage. The recovered solution is then sent back into the tank of the spraying machine. Tests were performed in order to evaluate the efficiency of the equipment, aiming to establish the dependency between the solution retrieval rate and the position of the panels. For these tests the machine was equipped with flow meters for measuring the total amount of liquid drawn from the tank and the amount of liquid recovered by the means of the vertical panels

Studies regarding energy consumption variation and drying time for corn seed in laboratory conditions

The drying process for grain seeds ensures optimal conditions for storage and stops microbiological processes. In order to improve the drying process of corn seeds an was installation designed and built, aiming for the dehydration of cereal seeds in laboratory conditions. The purpose of this study was to determine the optimal operating parameters of the drying process in order to maximize the technological effect, namely to minimize the drying time and the energy consumption. To achieve this goal, corn seeds with humidities between 16-25% were subjected successively to be dried, in three adjoining cells with 50 mm thickness each. During the research the structural and functional parameters for the dehydration rig were modified, namely the velocity and temperature of the drying agent, until the corn moisture reached 14%, aiming to assess their influence over the duration and energy consumption per product unit. The experimental research displayed variations between 0.006 and 0.03 kWh/kg for energy consumption, and between 2 and 150 minutes for the drying time. A total number of 80 experimental variants were studied during the research, the lowest values of the drying time being recorded at a speed of the drying agent of 2.5 m/s with a temperature of 80 °C and the minimum values of energy consumption at the speed of 2 m/s with a temperature of 80 oC. The research proved that the functional and technical parameters have a major influence over the process duration and energy consumption

Studies on quantitative meat productions of Kabir poultry

The research aimed at evaluating the quantitative production of meat (the yield at slaughter, the weight of the cut regions and the weight of the edible organs) in birds of the Kabir breed (10 males and 10 females) slaughtered at the age of 50 days. The fresh slaughter yield was 68.51% in males and 68.12% in females, with an average of 68.31%; after refrigeration the yield, the average value obtained for the two sexes was 67.62% (67.72% in males and 67.51% in females). Regarding the proportion of the cut parts, the average values obtained for the two sexes were 20.22% for the chest (21.02% for males and 19.41% for females), 24.86% for whole legs (25.92% for males and 23.80% for females), 11.28% for wings (11.47% for males and 11.09% for females) and 43.65% for back (41.59% - male and 45.70% female). The average weights determined for the internal organs were 36.32g in males and 31.83 g in females in the case of liver, 8.31 g in males and 6.34 g in females in that of hearts and respectively, of 31.98 g-males and 29.16 g-females in the case of gizzard. In conclusion, it can be stated that the birds of the Kabir breed slaughtered at the age of 50 realize a satisfactory production of meat, both in terms of the yield at slaughter and the weight of the anatomical regions

Preliminary tests regarding the operating conditions and modeling of the energy consumption for a domestic refrigerator

Energy saving and resources and environment preservation are key factors for the sustainable development of our society and hence domestic appliances are also targeted for energy efficiency improvements. Because refrigerators are the largest energy consuming appliances in households due to their widespread use and continuous operation there is a need for rigorous investigations regarding the energy consumption and efficiency of these devices. In the present paper the results of experimental tests are presented; in order to predict the energy consumption of the appliance in different operating conditions (ambient temperature, load and door openings) a simplified model was developed, based on the experimental data. A statistical analysis of the model was then performed in order to evaluate the goodness-of-fit between the model and the experimental data. The tests were performed in different days (starting at 7 a.m. each day) between may, 2015, and september, 2015. As the aim was to obtain results for two different ambient temperatures (250C and 300C) there was a selection of the results in order to achieve this goal; for the selected tests the actual mean environmental temperatures were: 25.080C and 30.040C respectively. The Multi linear regression method was used in order to develop the energy consumption model. The results confirmed that refrigerator load and ambient temperature have a significant effect on the energy consumption, when there was no door opening during the test period; when door openings were taken into account the significance of the above-mentioned factors was diminished

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)

Spatial prediction of soil qualitative variables using logistic regression and fuzzy techniques. Study region: Dobrovăţ basin (Central Moldavian Plateau)

The present study attempts to test the performance of two statistical approaches, namely the binary logistic regression and fuzzy techniques for spatial prediction of soil types. The study area is Dobrovăţ basin, located in NE Romania, within the Central Moldavian Plateau. The input parameters are the digital elevation model, slope, topographic wetness index, mean annual temperatures and precipitations. The logistic regression approach proved successful in estimating the spatial probabilities of Aluviosols, Chernozems, Preluvosols and Luvosols and generally failed in predicting the locations of Phaeozems. The fuzzy approach, implemented through SoLIM software, proved successful in predicting the occurrences of Aluviosols and Luvisols. On the whole, both methods managed to assign the same soil type as in the soil survey map for 55-56% of the basin. Though it is clear that the approaches need to be further improved, they do present, in the authors opinion, potential for the purpose of predicting soil qualitative variable