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This study aimed to evaluate the effect of solar drying on the physical, chemical, and sensory properties of lemongrass grown in Antioquia, Colombia. Two single‐factor experimental designs were used. The first one, evaluated the drying method: dryer with solar collector and ventilation cycle programmer (D2), African Drying Bed (ADB), and Traditional Drying (TD); with load of 7 kg/m2. The second experimental design evaluated different loads (7 kg/m2 and 10 kg/m2) in dryers D2 and D1. The following analysis were performed: drying time, moisture content, color, volatile compounds, and sensory. Drying times were 26.3 h for D2 and 30.2 h for D1. The drying time was higher in ADB and TD. There were no significant differences in a* for the samples D2 (−2.23) and D1 (−1.41), which had a lower loss of green color, indicating a lesser degradation of chlorophyll against ADB and TD. Geranial and neral were found in a higher amount, isogeranial and β‐myrcene were also identified. D2 and D1 presented a higher aromatic intensity with overall quality of 7.1 and 6.9, respectively (0–10 scale). With the use of the dryers inside the greenhouse, drying times were reduced, generating a product with better characteristics in color and sensory attributes. Practical applications: Almost all the seasoning and infusion industries in Colombia import the spices used as raw material in their products, even though with inferior quality from the sensory point of view, however, complying with other commercial criteria. The cost of dehydrated lemongrass imported in Colombia is higher when compared to other imported spices. Lemongrass grown in Antioquia, Colombia, presents some drawbacks in its postharvest processes, which makes its commercialization difficult at the national and international level. The results from this research show that using dryers with solar collector, fan, and ventilation cycle control; located inside the greenhouse solar dryer; it is possible to better control the drying process, obtaining competitive products at the industrial level, which could economically help producing families. Moreover, the times for drying are decreased and a product that meets the quality standards required by the industry in generated, overcoming those obtained from the traditional drying methods currently used. [ABSTRACT FROM AUTHOR]

Relevance. The article describes zones with one or another predominant type of melioration depending on the territorial location of the reclaimed lands, a brief classification of channels is given according to design features, cross-sectional shape, throughput capacity and technical and operational characteristics. Channels are the main elements of reclamation systems. Ensuring high-quality operation of channels with the required bandwidth guarantees the efficient operation of the entire reclamation system. Characteristic canal deformations that occur during operation are given, as well as factors affecting the throughput of canals, such as the appearance of sediment, silting and grass vegetation, the growth of shrubs and small trees. The article presents sewer cleaning machines used on canals of reclamation systems during cleaning and restoration work, describes their design features for cleaning canals of various types and cross sections. Canal cleaners are described, which, according to the mode of operation, are both intermittent and continuous machines, which most effectively and efficiently clean the bottom and slopes of channels of various reclamation systems. The article also provides an explanation of the increase in the efficiency of canal cleaning and the subsequent high-quality work of the reclamation system in the case of using various complexes of sewer cleaning machines, including a variety of machines with different working bodies, sizes and quantities. The choice of the number of machines is directly related to technical and economic indicators: the use of a large number of machines may not be economically feasible, and the use of a minimum number of machines will not provide the re-quired cleaning. Thus, it is important to choose the optimal number of machines of various sizes that form a separate complex.

Methods such as landfilling, incineration, and aerobic composting of waste are not suitable methods for their management because the production of greenhouse gases and the accumulation of vermin and high cost and the need for a lot of space are the problems of using these methods. The purpose of this study is to select a suitable method with the lowest energy consumption and maximum efficiency in the use of waste. For this purpose, a dryer was designed and fabricated for vegetable and food waste. The most suitable method of waste drying, the method of moving the mass using a helix, was selected. In this food waste dryer, to prevent energy loss, the tank of the device was made of double walls, and ceramic insulation was used between the two walls, and the perforated tank inside the device will cause uniform drying by spreading heat to all parts of the waste. Hot air from the tank outlet was also used. The results of the calculators showed that about 69,000 kJ of energy is needed to remove about 30 kg of moisture from the waste. This high capacity will be able to be used in small and large restaurants and kitchens and for livestock consumption. [ABSTRACT FROM AUTHOR]

Introduction. Dehydration of heat-sensitive and easily oxidized food products require particular temperatures. Exposure to ultrasonic vibrations is an alternative dehydration method that presupposes moderate thermal treatment. The research objective was to identify the optimal range of sound pressure and to design a small-volume dryer. Study objects and methods. The study featured two novel ultrasonic potato dryers at t = 60 ± 1°C and a drying agent flow rate of 0.50 ± 0.03 m/s. Results and discussion. The analysis of the drying curves revealed a period of constant flow rate at a low ultrasonic exposure and its absence at a high level of exposure of ≥ 160 dB, which indicated the start of the ultrasonic dispersion process of liquid from the potato surface. The dispersion occurred due to cavitation spraying of liquid without phase transition, which significantly reduced energy consumption. As the sound pressure increased in the range from 150 to 165 dB, the drying speed increased up to 26% by 5 dB. The optimal range of the sound pressure was 160–165 dB, which optimally combined energy consumption and drying time. The research resulted in two 6 kg horizontal and vertical drum dryers that provided even ultrasonic exposure during drying. Conclusion. The convective ultrasonic potato drum dryers reduced the drying time by 44–47%.

Various drying techniques have been operated to determine the energy requirements for drying mint leaves. The investigates were approved with different air-drying temperature of 30, 40 and 50 °C at different air velocity of 1.0, 1.5 and 2.5 m/s in hot-air dryer. The infrared and hybrid dryers were performed at different infrared intensity 1000, 2000 and 4000 W/m2 with same conditions of air velocity and temperature of convection drying. Under hot air convection, the energy consumption reduced significantly by increasing the air temperature while increases with rise in velocity. While the energy consummation decreased by increasing the infrared intensity using hybrid and infrared dryer but rise air velocity increased the energy. The minimum SEC was verified 2.6 MJ/kg with air temperature of 50 °C and at intensity 4000 W/m2, while maximum SEC 19.7 MJ/kg was observed at 30 °C and 1000 W/m2 under air velocity 1 m/s. The lower SEC of 2.6 MJ/kg was noted applying the hybrid dryer, which was 92.1 and 49.4% lesser than infrared and hot-air dryers, respectively. The optimum condition was conducted to 1.0 m/s, 50 °C, and 4000 W/m2 under hybrid dryer for efficient drying of mint.

The article presents aspects related to energy potential of the shredded biomass from agricultural secondary production, coming from maintenance operations to cutting trees and vines and an original solution of dryer with vibrating fluidized bed with continuous operation equipped with adjustments of the transit time of biomass in the dryer. Also, it was analysed the dynamic behaviour of the biomass tray as well as of a biomass particle for the variant of vibrating fluidized bed. [ABSTRACT FROM AUTHOR]

The article addresses the drying of cellulosic vegetable waste from fruit growing, and viticulture in an infrared tunnel dryer with conveyor belt. Data are presented regarding the average mass resulting from cutting, energy efficiency, calculation of drying speed and drying rate. Also, are presented some of the results of the dryer test according to the test methodology. [ABSTRACT FROM AUTHOR]

It is necessary to dry the inner surface of the pipeline before gas delivery starts. This requirement may vary depending on the product and the use, but can also be categorized as preventing internal corrosion in pipelines and meeting the desired moisture properties in the product being transported. During drying, it is aimed to remove water and foreign substances in the liquid or steam inside the pipe. In this study, it is suggested that "Gas cooled with heat recovery, heatless adsorption combined compressed air dryer", which is developed for drying natural gas pipelines, to be used. In account of the deficiencies in the existing systems, a useful combined pressurized air dryer model has been designed with the necessary improvements. While being designed, it has been aimed for this model to be energy-efficient and long-lasting, also it has been aimed for it to reduce the drying time of the line, as some of the first priorities.

Featured Application: This document is aimed at the agricultural sector to assess the energy consumption and problems associated with drying equipment used to dry rice and corn. Drying is considered one of the industrial processes that requires more energy than other processes, being a topic of much interest to the agricultural sector, especially the evaluation of energy consumption for rice and corn dryers. To meet this goal, an overview survey matrix and protocols for temperature measurements of dryers were developed. The study evaluated 49 rice dryers and 14 yellow corn dryers. As a result, it was determined that the oversizing of the fan/extractor and the dryer engine generates a high energy consumption, added to the lack of insulation in the heat ducts. Therefore, the drying productivity index is very low in dryers using liquefied petroleum gas (LPG) being 0.14 dollar/quintal for rice and 0.27 dollar/quintal for corn and using biomass reaches 1.4 dollars/quintal. In relation to energy losses, these account for more than 55%. Inadequate energy management in drying processes directly influences the marketing chain of products, the losses of which are caused by fluctuations in the price of rice and corn on the domestic market, with the agricultural sector having to generate an energy efficiency plan. [ABSTRACT FROM AUTHOR]

The objective of this study was to identify the incidence of the local thermal conductivity of a fluid in a tray dryer by means of CFD simulation. In the experimental part, identical pieces of mandarin epicarp (Citrus reticulata) were dried at 40 °C at two air inlet velocities (3.5 m/s and 5.5 m/s). For the simulations, equations of energy, continuity and momentum were used, which were solved with ANSYS software (Student v.19.2). The simulations showed spatial variations in the eddy viscosity and thermal conductivity of the air generated in the dryer, where higher experimental moisture values correspond to lower values of the eddy viscosity (<0.0001 P×s) and thermal conductivity (<0.45 W/m²×K). Therefore, this study proposes that in the design of tray dryers, the drying kinetics should be reported in values of the effective thermal conductivity, which must be homogeneous to ensure homogeneity in the product. [ABSTRACT FROM AUTHOR]

Drying is considered one of the industrial processes that requires more energy than other processes, being a topic of much interest to the agricultural sector, especially the evaluation of energy consumption for rice and corn dryers. To meet this goal, an overview survey matrix and protocols for temperature measurements of dryers were developed. The study evaluated 49 rice dryers and 14 yellow corn dryers. As a result, it was determined that the oversizing of the fan/extractor and the dryer engine generates a high energy consumption, added to the lack of insulation in the heat ducts. Therefore, the drying productivity index is very low in dryers using liquefied petroleum gas (LPG) being 0.14 dollar/quintal for rice and 0.27 dollar/quintal for corn and using biomass reaches 1.4 dollars/quintal. In relation to energy losses, these account for more than 55%. Inadequate energy management in drying processes directly influences the marketing chain of products, the losses of which are caused by fluctuations in the price of rice and corn on the domestic market, with the agricultural sector having to generate an energy efficiency plan.

Air heating by heat recovery using air-to-air heat exchangers (AHX) and heat pumps (HP) was analyzed for a typical spray dryer with inlet ambient air heated to 200 °C and exhaust air with dry bulb of 76 °C and dewpoint of 38.5 °C. The HP design is a tradeoff between greater heat recovery and lower COP as evaporation temperature decreases. With an evaporation temperature of 25–30 °C, it was possible to provide up to about 40% of the air heating load with more than 20% lower energy cost. The transcritical cycle, with dehumidification of exhaust air at a constant temperature and inlet air heating in the supercritical region, is thermodynamically well-matched to the drying process. The ideal critical temperature is between 70 °C and 110 °C, so a trade-off between efficiency, cost and safety may be needed with respect to refrigerant choice. Refrigerants R134a looks most promising while R32 and R290 also have good energy efficiency but are flammable. Economically for the typical spray dryer in New Zealand, only use of an AHX is attractive but is limited to about 20% of the air heating. Combining with an R134a HP to get higher heat recovery than an AHX alone would only be attractive if HP capital costs could be reduced significantly to less than about NZ$300 kW −1 heating capacity. [ABSTRACT FROM AUTHOR]

Cheeses are analyzed as vacuum drying objects. An experimental vacuum drier and its elements are schematized. The operating principle of the experimental setup is described. Moisture is demonstrated to be among the most important components of cheese. The physicochemical composition of cheeses is considered. The forms and energy of moisture binding in cheese are discussed. The hygroscopic and thermophysical properties of cheeses are reported. The kinetics of the vacuum drying of cheeses has been investigated. The vacuum drying of cheeses includes two stages: the drying rate is constant at the first stage and decreases at the second stage. The temperature curves of cheeses have been plotted in the temperature–moisture weight fraction coordinates. Drying curves in the heat load–time, temperature–time, and moisture weight fraction–time coordinates have been obtained and analyzed for various cheeses. Cheese drying rate curves have been constructed by graphical differentiation. The maximum cheese drying rates have been determined. Equilibrium moisture content values for cheese drying have been found. The cheese shrinkage ratio has been correlated with the thickness of the cheese bed being dried and with the shape and size of cheese pieces. Cheese shrinkage at both stages of vacuum drying proceeds uniformly. Raising the drying temperature above the prescribed temperature reduces the shrinkage ratio.