Energy and Exergy Analyses of Rice Drying in a Novel Electric Stationary Bed Grain-Drying System with Internal Circulation of the Drying Medium

In our study, we developed a system to reduce both energy consumption and pollutant discharge during the drying process. We present a new technology, a stationary bed grain-drying test device based on the internal circulation of the drying medium (ICODM). A rice-drying experiment was carried out inside of it, and the influences of air temperature (AT) and air velocity (AV) on the energy and exergy efficiencies (EEE) as well as the improvement potential rate (IPR) and the sustainability index (SI) of the rice-drying process were studied. The following conclusions were obtained: when the rice was dried at a temperature of below 55 °C and an AV across the grain layer of 0.5 m/s, the average EEE during the drying process was 48.27–72.17% and 40.27–71.07%, respectively, demonstrating an increasing trend as the drying medium temperature increased. When the rice was dried using an AV across the grain layer in the range of 0.33–0.5 m/s and a temperature of 40 °C, the two values were 39.79–73.9% and 49.66–71.04%, respectively, demonstrating a decreasing trend as the drying medium flow velocity increased. IPR and SI were 4.1–8.5 J/s and 1.9–2.7, respectively, at a drying temperature of 30–55 °C and an AV of 0.33–0.5 m/s. These conclusions can provide helpful guidance for the optimization and control of the rice-drying process in terms of saving energy.

Development of the technology of production of cheese ‘Suluguni’ for farms

The aim of the research is the development of a technology for the production of ‘Suluguni’ cheese for farms from milk of cows. Investigations of the chemical composition and physicochemical properties of cows’ milk were carried out using by ultrasonic method. It was found that the mass fraction of protein in milk is 3.19±0.02%, fat is from 4.32±0.06% to 5.07±0.08%. For the production of cheese, milk was standardized. The protein content in normalized milk is 3.37±0.02%, fat - 2.84±0.03%. The ratio of the mass fraction of protein and fat in normalized milk was 1.00:1.19. It was found that the milk of cows meets the requirements for raw materials for the production of cheese. We have developed a technology for the production of brine cheese ‘Suluguni’, which consists of the following operations: receiving milk, preparing milk for making cheese, fermenting, curdling and processing the curd, setting grain, drying, cheddaring, melting, forming a cheese head, salting, storing, transportation and sale of products. Cheese meets the requirements for organoleptic, physicochemical and microbiological indicators. The research results make it possible to recommend to farms the technology for the production of ‘Suluguni’ cheese with cheddaring and thermomechanical processing of the cheese mass.

Development of technological scheme of microwave - units for grain drying

In the agriculture of Ukraine, a variety of drying installations are used, the design of which should ensure uniform heating and drying of grain, while at the same time allowing to control the temperature and humidity in the grain mass. The choice of an appropriate dryer can significantly improve the quality of dried grain, increase production profitability, increase production, reduce drying costs, and reduce energy costs. Currently, the most common drying method is convective, the disadvantages of existing convective grain dryers are low efficiency, low specific moisture removal, uneven drying, high costs of the drying agent, high energy consumption. The purpose of the study is to develop a drying plant designed for high throughput. The use of grain drying technology using microwave electromagnetic fields provides a number of significant advantages over conventional dryers that use only a thermal agent. Grain drying technology using microwave electromagnetic fields can be used in combined dryers. The technological scheme of the drying installation is developed, which is based on the principle of microwave heating, which allows to intensify the external and internal transfer during drying. In the developed scheme the drying process takes place in three working zones. In the first zone, heating is carried out by irradiation with an electromagnetic field in the microwave range of seeds to a certain temperature, the second - the aging of the seeds, where moisture is released in the inter-grain space. In the third zone, the layer is blown by air flow with the organization of fluidization. The main design and mode parameters using the software environment "Flowvision" are determined. Key words: grain, microwave oven, dryers, installation, electromagnetic field

Calculation of the components of the temperature measurement error by a resistance thermocouple of an installed unbalanced bridge

The article has devoted to solving an urgent problem related to the determination and calculation of the components of the temperature measurement error. A grain drying machine had selected as the object of research, in which the temperature of the grain at the exit from the machine is measured with the help of a Cu50 resistance thermocouple installed in an unbalanced bridge. It had found that the scale of the measuring device, calibrated in degrees Celsius, will have a nonlinearity error, which increases towards the end of the measurement range. For the Cu50 resistance thermocouple installed in the grain drying machine, when measuring the temperature in the range of 0 … 100 °C in absolute terms, the nonlinearity error was 0.3 mA, in relative terms - 4.4 %, which is quite large. The measurement error has calculated with a tolerance for the nominal resistance of the thermistor ± 0.1 Ohm, which in the given form was 0.5%. The resulting value indicates that this component will have an insignificant effect on the total measurement error. The measurement error due to the supply voltage drop by 0.2 V in relative form was 4.2 %. Thus, the voltage drops when using an unbalanced bridge will have a significant effect on the measurement result.

Bronze Age Funerary and Later Prehistoric Activity at Badminston Farm, Fawley, Hampshire

Archaeological excavations were undertaken by Southern Archaeological Services Ltd. between 1999 and 2010 at Badminston Farm, Fawley, on the eastern edge of the New Forest, adjacent to Southampton Water. The excavations identified evidence of near- continuous human activity from the early prehistoric period to the present day. Mesolithic activity was followed by Early Bronze Age pits, containing 'placed' flint assemblages. Evidence of Bronze Age funerary activity included deflated barrows/ring ditches, and associated cremations. Late Bronze Age ceramics were absent but a hoard of 68 Armorican-type socketed axes may have been a votive offering marking the 'ancestral' barrow which would have been visible here. Other Bronze Age evidence included two burnt mounds and an ill-defined structure possibly associated with weaving. Iron Age activity was represented by a number of pits containing domestic pottery, while Late Iron Age and Romano-British ditches may have formed part of an enclosure. A significant assemblage of non-local worked stone attests to long distance exchange, and the possibility of a nearby farmstead. Medieval activity was represented by pits, ditches and stakeholes, with some evidence of an enclosure or structure associated with grain drying. Later land divisions and a WWII radio communication station dominated more recent use of the site.

FEATURES OF TEMPERATURE REGIME IN A CONTACT TYPE UNIT WHEN DRYING SMALL SEED CROPS

When creati ng modern eff ecti ve complex technical systems that realize the processes of thermal impact on bulk agricultural materials with the required quality and at a high energy level, it is important to know the conditi ons of heat and moisture transfer. The target functi on of our research was scienti fi c substanti ati on of the main thermophysical parameters of the studied process of thermal eff ect on the drying product as a whole, as well as identi fi cati on of the eff ect of the created temperature regime of the drying unit on the temperature gradient when heati ng the treated seeds, and, ulti mately, on the effi ciency of the enti re process. In case of contact drying of small-seeded crops, both external heat and moisture exchange processes are carried out - from the surface of the treated seeds to the external environment, and internal - the migrati on of heat and moisture inside the seeds. The main quanti tati ve factor that most fully describes the mechanism of moisture transfer is the Bio criterion (Bim). This criterion establishes a relati on between such parameters of the contact drying process as the intensity of moisture exchange on the surface of the processed grain and its moisture conducti vity. The descripti on of the process is reduced to solving an internal problem for the moisture contained in the processed grain, when considering the latt er as a colloidal body, Bim = 0.16. In this case, the removal of moisture with its transformati on into steam directly depends on the energy consumpti on for the heat treatment process. The driving force of this process is the temperature gradient arising from thermal acti on. Studies have established that the kineti c coeffi cient, which most fully describes this phenomenon, is the thermal and moisture conducti vity coeffi cient or the thermal gradient coeffi cient δ. This parameter characterizes the moisture content change in the processed grain at a temperature gradient equal to one degree Celsius. In order to confi rm the above theoreti cal dependencies, experimental studies were carried out to identi fy the features of contact thermal eff ects on various small-seed crops. Based on the results of the studies, it was revealed that the following operati ng parameters have the greatest infl uence on temperature regime during grain drying in the developed contact type grain dryer: the temperature of the heati ng surface and the rotati on frequency of the transporti ng working body. In this study, the rotati on frequency of the transporti ng working body was changed from 30 min-1 to 110 min-1, and the temperature of the heati ng surface - in the range from 40 ºС to 100 ºС. It was revealed that the temperature gradient of grain heati ng in the developed installati on for grain drying at appropriate drying modes is 9 ... 12 ºС and does not signifi cantly depend on the type of processed seeds. When improving the operati ng parameters of the drying process of seeds of one crop, it is possible to operate the developed grain dryer without loss of quality during heat treatment of small seeds of other crops.