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

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

Researches regarding the aggresiveness of the active parts over the soil

Researches aiming to establish the effect of the active parts of the agricultural units over the soil’s physical degradation were developed; several variants regarding the machinery used for soil tillage, for maize growth, were taken into account (including hoeing). For each variant the bulk density and soil penetration resistance were measured, as well as the average weighted diameter and the water stability of the soil el

Impact of agricultures of traffic over phisical of mechanical properties of soil in over crop yield

Anthropic soil compaction is a consequence of exaggerated traffic due to soil works, transport activities etc. In order to evaluate how the soil physical properties and the crop yield are affected by the traffic of the agricultural units soil compaction was evaluated for the autumn wheat. For each variant the bulk density and soil penetration resistance were measured, as well as the average weighted diameter and the hydric stability of the soil elements; the crop yield was also evaluated. Based on the experimental results the best variant was established, taking into account soil compaction

Research on the influence of air speed on the kinetics green malt drying

In breweries its know that malt is made from barley blank, and is a natural product rich in enzymes and vitamins. In order to optimize the work for drying green malt has been investigated in laboratory conditions. The malt subjected to drying was achieved using Jacobsen germination table. Research on dryng malt were made in the laboratory with a vertical air drying with a drying agent, heated air. The main goal in this work was to monitor the work process for drying green malt moisture of 46.31 % and a thickness of 1 cm. Dehydration was carried out at different speeds of the drying agent in order to observe how and when the evaporation of water. We have used four samples of malt obtained under the same conditions from the same batch of barley with the same parameters of final moisture, but which has been dried in the same diagram of temperatures but at different speeds of the drying agent (warm air). The speed of drying agent was 1.1 m/s, 1.5 m/s, 2.1 m/s and 2.5 m/s. The air temperature in the dryer was between 44 oC and 80oC. The time consumed for drying of each of the four samples was the same for each. It should be mentioned that all the four samples of malt had the same mass and the same parameters (moisture content W = 46.31) and temperature (21 °C) at the beginning of the drying. The results obtained at the end of the drying process shows different values of the humidity in the final malt, very close to the value of the air velocity at 1.1 m/s and 1.5 m/s. It should be mentioned that the lowest moisture content is obtained if the speed experience hot air was 2.5 m/s. The conclusion is that the drying agent used at the same temperature but with a higher circulation rate (in this case 2.5 m / s) to facilitate the evaporation of large quantities of wate

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

Researches regarding the design and achievement of a fertilization machine in aggregate with a motoculture for greenhouses and solariums

The experiments were focused on the design and execution of the equipment for the administration of solid chemical fertilizers within the disciplines of Mechanization of the Ion Ionescu de la Brad University of Agricultural Sciences and Veterinary Medicine in Iasi. The determination of uniformity administration of solid chemical fertilizers was achieved using the gravitational method. Experience have shown that the equipment satisfies the qualitative requirements and qualities of fertilizer uniformity using a high precision method for determining the distribution of the fertilizer

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