Process intensification in Desalination operation in mesoscale systems

Development of desalination technologies has been identified as vital to fulfilling future water demand. Directional solvent extraction is one of the promising membrane-less seawater desalination method. Membrane based desalination technologies incur a higher cost and are subjected to fouling after certain period of time of operation and needs regular maintenance and monitoring. It is believed that, overcoming these drawbacks is possible by working in the millimeter scale through the incorporation of pulsatile flow and air damper. This work presents a theoretical approach designed for a certain nominal length of an air damper, placed on the top of the extraction column, with the flow in the desalination unit being semi pulsatile combined with secondary pulsation generated due to air suspension during solvent extraction applied for desalination operation. Henceforth a theoretical approach based on the above stated parameters, it is found theoretically that with increase in flow pulsation amplitude and frequency the extracted salt concentration in solvent increases. The application of infra red radiation in preheating section with the help of a infrared heating device is the crucial part of DSE process, cooling is planned to achieve via a heat exchanger or atmospheric cooling. The total exergy and energy calculations will be conducted to see the energy requirement for the process. It is planned to calculate the salt separation efficiency of sea water (on the basis of WHO guidelines) to fresh water, alongwith flow rate and processing time.

Deep bed drying performance on paddy using hybrid infrared-solar dryer

Hybrid infrared-solar dryer has a potential for drying fruits, vegetables, and grains such as paddy. This study aims to assess the performance of hybrid infrared-solar dryer on paddy in different of deep layer. Three different infrared heaters were used with a power of 25 W, 50 W, and 100 W. The hybrid infrared-solar dryer equipped with sensors placed in an open space so that sunlight can reach the drying chamber. The paddy samples were dried in different of deep layer (2 cm, 4 cm, 6 cm) until it reaches a moisture content of 14%. The input sensors in the drying chamber such as temperature, humidity, and moisture content were recorded using microcontroller and stored in Microsoft Excel® using the Parallax Data Acquisition tool. The algorithm was developed in order to control the heater from the input of temperature and humidity sensors by adjusting turn on/off relay. The study confirmed that the infrared heating power of 100 W is recommended for paddy drying if the ambient temperature is unfavourable (temperature less than 30°C). In general, the hybrid infrared-solar dryer with a power of 25 W-100 W has a potential to dry paddy quickly at a thickness of 2 cm-6 cm with a time range of 90-150 minutes.

Desiccation of hemp seeds by high temperature micronization

In several cases, it is necessary to use heat treatment of cereal products to reduce moisture, inactivate some enzymes, increase storability and processing efficiency. One of the methods for heat treatment is high-temperature micronization — heating in a flow of infrared radiation. The method is convenient in the conditions of small and medium-sized enterprises. The aim of the study was to obtain the factual material regarding heating and desiccation of hemp seeds when heating in the flow of infrared radiation and modeling of the heating and desiccation processes. The experimental dependences of a seed temperature and moisture on heating time at different regimes of infrared heat treatment were obtained. Mathematical models were proposed for changes in a seed temperature as a function of time and moisture content depending on a seed temperature and the initial moisture. The desiccation models were based on simplified solutions of the system of differentiated equations of heat and mass transfer obtained by academician V. A. Lykov and his students. Model coefficients were identified by the results of the experiments. Analysis of the obtained coefficients shows that it is possible to use one coefficient in the examined models without a significant loss of the prognostic accuracy. The proposed models describe the experimental data quite well upon constant conditions of infrared heating of hemp seeds (irradiance and temperature in the treatment zone). However, heating conditions significantly affect the time dependence of the relative moisture (W/W0) and temperature increment ΔT(t). At the same time, it follows from the processing results and available experimental data that the character of the dependence W(ΔT) is determined by the initial moisture and is stable (that is, weakly depends on heating conditions).

Optimization of Infrared Heating Conditions for Precooked Cowpea Production Using Response Surface Methodology

The infrared heating of preconditioned cowpea improves its utilization and potential application in food systems. This study investigated the effect of optimizing preconditioning and infrared heating parameters of temperature and time on cooking characteristics of precooked cowpeas using response surface methodology (RSM). The moisture level (32–57%), infrared heating temperature (114–185 °C), and time of processing the seeds (2–18 min) were optimized using a randomized central composite design to achieve optimal characteristics for bulk density and water absorption. A second-order polynomial regression model was fitted to the obtained data, and the fitted model was used to compute the multi-response optimum processing conditions, which were the moisture of 45%, the heating temperature of 185 °C, and time of 5 min. Precooked cowpea seeds from optimized conditions had a 19% increase in pectin solubility. The total phenolic and total flavonoid contents were significantly reduced through complexation of the seeds’ phenolic compounds with other macromolecules but nonetheless exhibited antioxidant properties capable of scavenging free radicals. There was also a significant reduction in phytate and oxalates by 24% and 42%, respectively, which was due to the heat causing the inactivation of these antinutrients. The obtained optimized conditions are adequate in the production of precooked cowpea seeds with improved quality.