Assessing a dryer state using the parameters of a spent drying agent

This paper concerns with heterogeneous modeling of deep-bed grain dryers based on two-phase model by taking into account coupled heat and mass transfer within grains. This model also consider axial mass and heat dispersion in the fluid phase. The dynamic two-phase equations are solved numerically by finite difference with alternating direction implicit method algorithm, and then applied to simulate humidity and temperature profile of drying gas across dryers together with moisture content and temperature of grains. The capabilities of these models were compared with experimental data obtained from available literatures, under drying conditions such as temperature and absolute humidity of drying gas and moisture content of grains. The simulation results show that the dynamic of corn drying within the bed is well predicted by the two-phase model.

Maize is one of the most important economic crops in the world. The integrity of maize grains directly affects the economic value of the maize as a main commodity that depends on the percentage of grains broken (POGB) in mechanized harvesting. Decreasing grain processing breakage is key to achieving mechanical harvesting with high quality. It is difficult to ensure a low POGB, because it depends on different maize varieties, their moisture contents, threshing devices and harvester working speeds. In this paper, the effects of these factors on the POGB are investigated when the working speed of the harvester is 1.0 m·s−1, 1.5 m·s−1 and 2.0 m·s−1, respectively. The different threshing forms, including tangential-axial-flow (TAF), axial-flow with nail-tooth (AFN), axial-flow with rasp bar in big space (AFRBBS) and axial-flow with rasp bar in small space (AFRBSS), are summarized. The POGB of TAF was 5.4% and it was the lowest of four threshing devices when the working speed of the harvester was 1.0 m·s−1, which was suitable to thresh maize at a low working speed. Maize Demeiya No. 1 (DMYN1), XianDa205 (XD205), Demeiya No. 3 (DMYN3) and Hayu189 (HY189) were harvested at different harvester working speeds, and the POGB of maize DMYN1 was the lowest among the four maize varieties. The POGB increased with increases in the working speed of the harvester and the moisture content of the maize grains. The POGB reached a minimum value of 3.5% when maize XD205 with the lowest moisture content was harvested. The results can provide a reference for choosing the maize variety, its moisture content, the threshing device and the working speed of the harvester for decreasing grain processing breakage.

A method of determining the moisture content of bulk wheat grain

Abstract. Using the right equilibrium moisture content (EMC) relationship is critical for implementing successful aeration strategies and for determining the safe storage moisture content of grains and oilseeds. The oil content of sunflower seeds substantially affects the moisture equilibrium relationship, implying that a specific set of model parameters for each oil content range should be obtained. To overcome this practical limitation, the Enhanced Halsey model was developed incorporating a new parameter (D) to characterize the effect of oil content on the original Modified Halsey model. The constants A, B, C, and D of the model were obtained for a wide range of temperatures, moisture and oil contents. The simplicity of the Enhanced Halsey model and the possibility of adapting EMC as a function of oil content make the Enhanced Halsey model valuable for engineering applications (e.g., aeration controllers) and for predicting the safe storage moisture content of seeds with different oil contents, such as sunflower. Keywords: Composition, Grain, Isotherms, Oilseed, Relative humidity, Sorption, Storage quality.

The article deals with the problems of controlling the moisture content of grain and products of their industrial processing in industrial conditions, describes various electrical systems, a dielcometric method for measuring the humidity of various classes of products, and the construction of moisture control devices on its basis, and also analyzes the measuring transducer, as well as the measuring schemes of the humidity control devices under consideration. A sample of an emocostal moisture meter for determining the dielectric constant of grain products, both in laboratory and production conditions, and its metrological characteristics are shown, as well as a number of factors are noted, the dielectric constant for grain, which considers the temperature, material, which makes it possible to assess the degree and nature of the influence of each factor on the total error of measuring it. Humidity. The obtained results are relevant in the development of moisture control devices for such specific twerk and bulk materials of the agro-industrial complex, grain, and products of their processing. KeywordsGrainHumidityControlDeviceTransducerHigh-frequencyMeasurement

One of the most perspective directions of intensification of heat and mass transfer in the processes of drying plant materials and increasing the energy efficiency of drying plants is the application of a vibration field for mixing grain material while moving in the drying chamber. The analysis of existing vibration installations has revealed that the most promising is the usage of vibratory grinding chambers with spatial circulation of material for the implementation of grain heat treatment, in particular drying. As a result, it is proposed to use the proven element base of a vibratory mill as a working body of which grinding chambers with spatial circulation of the load are used. The article presents the structural and technological scheme of a vibratory thermal drying unit, the structural parameters of the unit, and a mathematical description of the grain drying process. The obtained differential equations constitute a mathematical model of the nonstationary process of continuous drying of grain material and determine the change in time, parameters of grain and steam-gas mixture at the outlet of the grain drying chamber. The constructed mathematical model of the drying process makes it possible to determine the modes of heating and dehydration of grain material during circulation in a vibrating chamber with a conductive energy supply and partial vacuuming of the chamber, to expand the technological capabilities of the "vibrating mill" type installations. The graphical dependences of the temperature and moisture content of grain over time, the data for which were determined experimentally, are presented when a monolayer of grain of mass m is heated on a heating surface of area F at a stabilized surface temperature θn. In this work, the kinetics of drying and heating of grain were obtained, which were used to calculate the parameters of the vibrothermal drying unit. Also, using the results of the experiments, the performance indicators of the vibration dryer created on the basis of the grinding chamber of the vibrating mill were determined.

Günümüzde tahılların nem içeriğini belirlemede elde taşınabilen birçok farklı tip portatif nem ölçüm cihazlarının piyasada yaygın bir şekilde kullanıldığı görülmektedir. Bu cihazların doğruluk ve hassasiyetlerinin belirlenmesi ve bu değişkenler üzerindeki etkili faktörlerin araştırılması, cihazların kalibrasyonu ve performanslarının artırılmasına önemli oranda katkı sağlayacaktır. Bu çalışmada, Türkiye piyasasında yaygın olarak kullanılan bazı tahıl nem ölçüm cihazlarının, tane mısırın farklı nem ölçüm aralıklarındaki doğruluk ve hassaslık dereceleri araştırılmıştır. Bu amaçla, üç farklı ticari nem ölçüm cihazı (KETT PM-450 Dökmeli, Wile-55 Sıkmalı, Pfeuffer HE Lite Kırmalı) tane mısırın farklı nem içeriği aralıklarında (%11-12, %16-17, %19-22, %23-25, %27-29 ve %30-31y.a.) denenmiştir. Bu ölçüm cihazlarından elde edilen verilerin doğruluk ve hassaslık dereceleri, referans fırın yöntemi kullanılarak test edilmiştir. Çalışma sonuçları, tane mısırın farklı nem içeriği seviyelerinde aletlerin doğruluk ve hassasiyet derecelerinin farklı olduğunu göstermiştir. Tane mısırın %11-31 nem içeriği aralığındaki yapılan ölçümlerde PM 450 cihazının ölçüm değerleri ile referans fırın ölçüm değerleri arasındaki en düşük fark, başka bir ifadeyle cihaz ölçümlerinin en doğru olduğu ürün nem içeriği aralığı % 21-23 (y.a.) olarak belirlenirken, Wile 55 ölçüm cihazının ölçümlerinin en doğru olduğu ürün nem içeriği aralığı % 14-15 (y.a.) ve Pfeuffer HE Lite Kırmalı nem ölçüm cihazında %11-12 olarak belirlenmiştir.

This article describes the use of weather data collected over several years for the development of strategies for planning and management of in-store grain drying operations. China was chosen for this study due to the size of its grain industry and the climatic diversity of the country. In-store drying is well established throughout China and the strategies chosen are determined by weather conditions prevailing in various regions of the country. Seven agro-climatic regions were identified, characterized by climatic conditions leading to particular storage practices. These regions include the Qingzang Plateau, Inner Mongolia Xinjiang, Northeast China, Northern China, Central China, Southwest China, and Southern China. In-store drying, combining drying and storage operations, reduces moisture content of grain from 18 to 14% (wb). It uses higher air flow rates than aeration. Weather data including temperature and relative humidity from the main storage regions in China were analyzed using computer simulations of in-store drying of three major cereal crops, namely, wheat, maize, and paddy rice. The findings from this study, related to equipment requirements and strategies to be used, provide a valuable tool for optimization of operations in the grain industry. The concepts developed could be applied in any grain-growing region in the world.

Mycotoxins are secondary metabolites of fungi that are toxic to humans and animals when consumed in contaminated food and feed.The Rwandan climate conditions like steady temperature and sufficient rainfall favor the growth of fungi leading to high probability of mycotoxins contamination.Mycotoxins get into maize throughout the value chain from the field to processed products.Maize is promoted in Rwanda under the Crop Intensification Program (CIP), for nutrition and food security.The aim of the study was to evaluate mycotoxins (Aflatoxin and fumonisin) levels in maize and assess awareness and factors associated with mycotoxin contamination in Rwanda.Maize samples (227 kg) from season B 2019 were collected in 15 Districts in five provinces of Rwanda after an interview with a representative of the household or cooperative using a structured questionnaire.The samples were analyzed for aflatoxin and fumonisin using Reveal Q+ and AccuScan Gold Reader.From the interview, most of the respondents were not aware about aflatoxin (59.7 %) and 99 % did not know the effect of mycotoxins on human health.The average of aflatoxin contamination in surveyed districts was 6.69±13 μg/kg.In general, 90.4 % of samples scored below the limit of aflatoxin level regulated in East Africa/Kenya regulation standards (10 μg/kg).The levels of aflatoxin ranged between 0 and 100.9 μg/kg.The means aflatoxin levels within districts ranged between 1.36±0.5 μg/kg and 13.75±25 μg/kg.Among 9.6 % of the samples containing aflatoxins above the EU and Kenyan regulations standard limit, 5.7 % were above the US standards of 20 μg/kg.Within clusters, the level of aflatoxin more than 10 μg/kg was 5 %, 7 % and 18 % for stores, household and market samples, respectively.From the study, as mechanical damage of grains, moisture content of grains and the temperature of the store house increased, Aflatoxin level also increased.Fumonisin analyzed in maize ranged from 0 to 2.3 μg/g and only one sample from market showed a slightly higher level of fumonisin than the EU and US limit of 2 μg/g.More effort for aflatoxin mitigation is needed at the market level.Farmers need to be aware and taught how they can improve their agricultural system and more knowledge on mycotoxin control is needed.The results point to appropriate measures to recommend for control of mycotoxins in Rwanda and awareness creation.

Barley: Effect of airflow reversal on fixed bed drying

The applications of computer vision system and tomographic radar imaging for assessing physical properties of food

A Comparative study was carried out to observe the response of Maize crop by using wastewater from shrimp processing industries at Rupsha Upazila under Khulna district during 2011-12. In the experiment, soil and water quality parameters were determined to sketch out the effect of growth and yield of Maize crop of the experimental area. The nutrient contents of water were analyzed for measuring pH, EC, salinity, sodium adsorption ratio (SAR), soluble sodium percentage (SSP), Hardness and some major ionic concentrations. For industrial wastewater, the average pH was 8.12 which reflected alkaline in nature. The values of SAR, SSP and Hardness were 4.28, 71.24 to 81.847 percent and 298.8 mg L-1 and for soil, the pH, EC and other major ionic concentration were determined and the value of wastewater irrigated soils was shown higher than the value of freshwater irrigated soils except magnesium. Loading of soil was not much higher except Na. For plant response, Plant height was significantly different from fresh water irrigation as well as leaf response was shown on average same results and moisture content of grain has indicated that yield was harvested at right time with yield response was moderately good in compare with fresh water. If proper management can be implemented for recycling this wastewater, then this wastewater can be used for sustainable production of maize crops.

The authors deal with the problem of mite infestation of stored grain in Czechoslovakia, where more than 10% of the grain is infested by Acarus siro L. and Glycyphagus destructor (Schr.). The methods of mite control hitherto used (fumigants CH3Br, HCN, and ALP) were poor and of short duration. Accordingly, the authors investigated the possibility of biological control using the predacious mite Cheyletus eruditus (Schr.). Some observations showed spontaneous biological control, culminating in the complete eradication of the grain mites. The investigation covered eight grain storages. Details are given of the characteristic course of observations in one grain store, and the results of seven other stores are summarized. In three other stores was studied the influence of cleanliness and moisture contents of grain on the development of mites. The authors found that the mites multiplied on uncleaned wheat (16% moisture content), on cleaned wheat (16% moisture content), and on dry, uncleaned wheat (14% moisture content) in the ratio of 100:10:1.Further details are given about two semioperational trials following the introduction of the predacious mite Cheyletus eruditus (Schr.). These trials were generally successful with the complete eradication of harmful mites.The authors report successful results on the introduction of the predacious mite into uninfested grain destined for long-term storage. They discuss 28 experiments with its artificial introduction (25 successful in biological control) and the course of an operational trial which showed good results as well. Experiences and results from semioperational and operational trials form the basis of a set of technological principles as a guide to practice. It is recommended that the predacious mite be collected from natural biotopes where complete eradication of harmful mites has already been completed. For successful results, the authors recommend artificial introduction in spring or autumn (temperature 5–10 °C) on the surface of grain in the proportion 1:100 to 1:1000 (Cheyletus eruditus Schr.: Acarus siro L. + Glycyphagus destructor Schr.).

Introduction . The widespread use of polyethylene sleeves worldwide has led to their application in various sectors of the national economy. For example, in the agro-industrial complex, polyethylene sleeves are an integral part of the modern method of storing crop products in the field. During the practical application of this storage method in Russia, farmers encountered various problems during their operation, including one of the main ones, namely a violation of the sleeves' tightness. Materials and Methods. The study focused on a non-stationary method of storing crop products in polyethylene bags (silo bags). The research methods included field observations conducted in the Central Federal District during the 2015–2023 agricultural seasons. Surveys of sites for the placement of grain-filled polyethylene bags were conducted over a nine-month period (summer, fall, and winter). Parameters studied included the moisture content of crop products and the degree of damage to the silo bags. Result s. A classification of processes for depressurizing polyethylene bags containing grain during storage is proposed (authorized and unauthorized). The main causes of unauthorized depressurization of silo bags have been identified: improper operation of silo bags at the production site; and the harmful effects of rodents and birds. It has been found that the baseline moisture content of the commercial product influences unauthorized depressurization of silo bags, as their greatest degree of storage damage was detected in grain with moisture contents up to 13.0%. It was established that the cause of grain moisture changes during storage is depressurization of polyethylene bags. Moreover, the nature of the depressurization affects the rate of increase in the grain's moisture content. The nature of damage to silo bags and polyethylene sleeve housings was determined, and the degree of damage (I-III) was established. Conclusions . The results of long-term field observations allowed us to identify the main causes of unauthorized depressurization of silo bags during storage of plant products. It was found that season and relative humidity influence changes in the overall moisture content of grain during storage. It was found that if unauthorized depressurization occurred in summer or winter, when precipitation is lowest, the change in grain moisture content is insignificant.

The present work makes use of experimental data for real part of microwave complex permittivity of spring oats (Avena sativa L.) at 2.45 GHz and 24 °C as a function of moisture content, as extracted from the literature. These permittivity data were individually converted to those for solid materials using seven independent mixture equations for effective permittivity of random media. Moisture dependent quadratic models for complex permittivity of spring oats (Avena sativa L.), as developed by the present group, were used to evaluate the dielectric loss factor of spring oats kernels. Using these data, seven density—independent permittivity functions were evaluated and plotted as a function of moisture content of the samples. Second and third order polynomial regression equations were used for curve fittings with these data and their performances are reported. Coefficients of determination (r2) approaching unity (∼ 0.95–0.9999) and very small Standard Deviation (SD) ∼0.001–8.87 show good acceptability for these models. The regularity in the nature of these variations revealed the usefulness of the density—independent permittivity functions as indicators/calibrators of moisture content of spring oats kernels. Keeping in view the fact that moisture content of grains and seeds is an important factor determining quality and affecting the storage, transportation, and milling of grains and seeds, the work has the potentiality of its practical applications.