From this study, the performance associated with an ohmic concentration system was analyzed depending on the second legislation of thermodynamics. The effect of sodium content (0-2% w/w), voltage gradient (5-11 V/cm) and electrode type (316L Saint, Al, and Br) were evaluated around the exergy elements. Nowadays the necessity for newest technologies in the area of food thermal processing with low strength consumption, high energy efficiency, and preservation the foodstuffs quality is growing. Ohmic heating is among the alternatives and latest technology in foodstuff thermal processing whereby the electrical amount of resistance of the meals itself builds heat as electrical current passes through it (Sakr and Liu, 2014). The huge benefits of the ohmic heating approach are the speedy and consistent heating procedure, improving product quality, lessening of energy consumption and keeping the cost of the task (Sakr and Liu, 2014, Farahnaky ain al., 2012, Moreno ou al., 2012). The previous analyze also expressed that Ohmic heating might be a promising approach in the juice industry particularly in the evaporation/concentration of fruit juice method. The process of making juice completely focus by regular vacuum warming needs cardio and capital (Nargesi, 2011). Most of the energy processes and heating equipment have low energy effectiveness.
Therefore , it is important for research workers and technical engineers to increase the thermal efficiency of heating systems employing engineering studies. Exergy analysis is a useful tool for considering the enthusiastic performance of an ohmic attention system intended for the production of tomato insert. The use of the exergy analysis can easily overcome the limitations of energy examination which concentrates only within the quantity of energy, and therefore becomes even more meaningful. Exergy analysis established of the strength quality mold during energy transfer and conversion (Prommas et al., 2012).
Also, Exergy can be described as more easily understood thermodynamic property than entropy to represent irreversibilities in sophisticated systems (Nanaki and Koroneos, 2017, Hammond and Winnett, 2009). From your second regulation of thermodynamics, exergy will help identify the irreversibilities linked to the energy flow as well as its conversion. Strength is defined as the ideal possible beneficial work a system may deliver because it undergoes a reversible process from your initial point out to the express of their environment, the dead state (Akbulut and Durmu, 2010, Prommas et al., 2012). The exergy method is a particularly useful tool in handling energy planning and decision-making for sustainable expansion.
Exergy analysis of the ohmic heating system of liquid food presents a novel method of performance analysis of ohmic systems, which may be specifically used in the industrial implementation of such systems. Bozkurt and Icier (2010) performed the exergy analysis of ohmic cooking food of ground beef in an ohmic water heater, and reported that the strength and exergy efficiency ideals for ohmic cooking procedure at the volt quality gradients among 20 and 40 V/cm were inside the range of zero. 69″0. 91% and 63. 2″89. 2%, respectively. Darvishi et approach. (2015) researched only volt quality gradient influence on thermodynamic facets of ohmic tomato juice concentration and their benefits revealed the values of energy and exergy efficiencies elevated with increasing voltage lean.
Choice of the suitable electrode in ohmic warming systems is among the important guidelines that need to be deemed. Undesirable electrochemical reactions at the interface the electrode and solution, and corrosion may well affect the effectiveness of the ohmic heating system and this can be avoided by opting for electrodes having a suitable materials (Adetunji et al., 2016, Alvarez et al., 2012, Assiry, 2003, Zell ainsi que al., 2009). The generated heat and efficiency values of the ohmic heating system will be dependent on the conductive nature of the materials to be highly processed and the power field power. Many analysts by adding salt to items increased the electrical conductivity and superior the warming performance and quality with the final product (Icier and Ilicali, 2006, Assiry ainsi que al. 2003, Zell et al., 2009, Marra ainsi que al., 2009, Icier et al., 2006). Assiry ou al. (2010) reported that the electrical conductivity increased with increasing dissolved ionic in solution since the electrical current is passed by the ions in the solution. A lot of researchers researched assessed the effect of electrodes type and salt content material regarding corrosion of electrodes, heating level, electrical conductivity, and top quality of final merchandise. But , ohmic heating software has not recently been studied from the point of view of the second law of thermodynamics (exergy analysis).
However, the research such as Darvishi et ing. (2015), Cokgezme et approach. (2017) and Bozkurt and Icier (2010) have only examined the effect of ac electricity gradient on exergy elements. In the literature review, it isn’t found any kind of studies about the effect of electrode type and salt content within the energetic functionality of the ohmic concentration system. Thus, the actual aim of this study was going to study the effect of salt content, form of metal electrode and voltage gradient around the energetic overall performance of the ohmic concentration program as the first work. Materials and methods Tomato fruits (Early Urbana111 Va. ) had been purchased by a local market, in Sanandaj, Kurdistan, Iran. After cleansing of tomato samples, the skin of tomato plants peeled utilizing a hot-cold water method. Peeled tomatoes had been processed in a plain mixer/juicer to produce recently tomato juice. Tomato drink was strained using a cleaner filter for the splitting up of seeds. Juice trials were stored at 20. 5 C during tests in order to slow up the respiration, physiological and chemical substance changes. The standard moisture content material of the tomato samples was as 9. 53 0. 12-15 (dry basis), as dependant upon the range at 1031 C pertaining to 24 they would (Hosainpour et al., 2014). Fig. you shows the static ohmic heating system.
The ohmic heating unit consisted of a cylindrical Teflon cell (50 mm internal diameter, 12 mm wall structure thickness, one hundred and fifty mm length), two detachable electrodes (three types: 316L St, Approach and Br) with a 95 mm gap between them and 2 millimeter thickness, a power analyzer (DW-6090, Lutron, Taiwan), two k- type thermocouples with Teflon lined (connected to digital thermometers), a voltage regulating transformer (1 kW, 0″320 Sixth is v, 50 Hz, MST ” 3, Toyo, Japan), and a computer. Kind of metal electrode (316L Street, Br, and AL) picked based on studies of Torkian et ‘s. (2017), Adetunji et ing. (2016), Alvarez et al. (2012), Zell et ‘s., (2011). Properties of electrodes and ohmic cell are presented in Table 1 . Three openings with diameters of 1 logistik and 12 mm had been created on the surface of the cell for insert of thermocouples and exit of vapor within the cell, respectively.
To prevent the flow from the juice via cell as a result of rapid drink boiling (from 10 mm hole), we used a column snare on the top surface area of the ohmic cell (Torkian et ing., 2015) because shown in Fig. 1 ) Variation of the mass sample recorded with a digital harmony (AD GF 600, Japan) with 0. 01 g accuracy which is placed under the ohmic cellular as displayed in Fig. 1 . About 100 g ( 0. 5) of fresh tomato juice with 20 C initial temperature was added through the column trap in the ohmic cell (cell is totally filled). Heating process was carried out before the final wetness content come to 2 . 43%0. 02 (dry basis) by making use of different concentration 50, 75, 90 and 110 Versus (as five, 7, 9 and 14 V/cm ac electricity gradient) for 50 Hertz frequency (Torkian et ‘s., 2017, Hosainpour et ing., 2014). It content with the tomato substance samples diverse in the range of 0. six to installment payments on your 5% (w/w) for several production corporations (Sobowale ain al., 2012).
According to the Fda, the maximum sodium content of tomato insert is 2% (w/w). Two levels of salt concentration you: 100 g/g (ratio of salt/tomato) and 2: 100 g/g (as 1 and 2% w/w) were furnished by the salt (NaCl) and results compared without salt sample as a control sample. Sodium added to tomato samples during the process by mixer/juicer in order to be uniformly distributed through the tomato drink. After each test, the electrodes had been rinsed utilizing a brush and distilled normal water. Voltage, current, mass and temperature data were measured during heating system and exceeded this information towards the computer which has a data logger.
According to the heating system control volume (Fig. 2), the exergy balance pertaining to the ohmic system was expressed as follows (Darvishi ou al., 2015): The rate of exergy transfer due to evaporation in the heating control volume was (Nanaki and Koroneos, 2017, Sarker et al., 2015): The specific exergy of the input or perhaps final product was computed using Eq. (3) stated as follows (Prommas et ‘s., 2010): The exergy efficiency was worked out using Eq. (4) explained as follows (Darvishi et approach., 2015): Exergy loss depends upon Eq. (5): The specific exergy consumption was determined using the following equation: Furthermore, the next equation was applied to get the dynamic improvement potential of ohmic concentration system (Icier ainsi que al., 2010, Cokgezme et al., 2017).
Statistical technique All of the info are expressed as suggest and common deviation beliefs from 3 replicate measurements for different heating system conditions. The ANOVA and Duncan check were used to analyze the result of salt content, volts gradient and electrode type on chosen properties on the 5% significance level (p=0. 05). The statistical analysis was performed by using software SPSS Sixth is v. 18. Also, the software Stand Curve 3D IMAGES, V4 was used to conspiring 3D perspective of the romance of guidelines and removal of regression equations. Results and dialogue The specific exergy required for the ohmic concentration of tomato juice can be shown in Fig. a few.
For all electrodes, exergy consumption decreased considerably (p<, zero. 05) since the volt quality gradient and salt content increased. This is because of the dramatic reduction in the concentration-time with an increase in voltage gradient and salt articles. The electrolytic content increases with the sodium concentration which will increases the electrical conductivity. Therefore the heat creating rate elevated inside the sample (Duguay et al., 2016, Icier and Ilicali, june 2006, Sarkis ou al., 2013, Darvishi ainsi que al., 2015). However , exergy consumption of Al electrode is higher than 316L Saint and Br electrodes under different attentiveness processes (p0. 05) additionally heating condition. The minimal specific exergy consumption of 316L Saint and Br electrodes was obtained installment payments on your 73 (MJ/kg water evp) and installment payments on your 85 (MJ/kg water evp), respectively, in high voltage gradient (11 V/cm). Fig. 5 demonstrated that the exergy effectiveness increased with increasing of voltage gradient and sodium content (p<, 0. 05). This outcome indicates that heating and water evaporation rates inside the sample had been quicker with higher salt content and voltage lean. Because the passing current through the sample was higher and this increased the heat generation charge in the test and consequently exergy efficiency increased significantly (p<, zero. 05).
Just like see in Fig. 5, the exergy efficiency of 316L St (10. 12-17. 63%) and Br (9. 84-16. 73%) electrodes is usually higher than the exergy performance of the ‘s electrode (8. 41-15. 17%). A similar pattern has been seen by Bozkurt and Icier (2010) in the ohmic preparing food process of gound beef, and Darvishi et ‘s. (2015) in the ohmic attention of tomato juice. They reported that the lower finalizing time and higher homogeneous heating system reduced the exergy failures or equivalently entropy technology, which supposed the increase inside the energetic effectiveness of the program. In order to calculate the suggest amount of exergy productivity at the wanted level of the variables, a variation of exergy efficiency was correlated as follows: Values of exergy loss for different heat conditions will be presented in Table installment payments on your The specific exergy loss beliefs varied among 2 . 25 and 4. 42 (MJ/kg water evp) for 316L St electrode, 2 . 39 and 5. 04 (MJ/kg water evp) for Bayerischer rundfunk electrode, installment payments on your 75 and 5. 11 (MJ/kg drinking water evp) intended for Al electrode, and significantly decreased since the voltage gradient and salt content increased (p<, 0. 05).
The treatment time was longer below low sodium content and voltage lean levels consequently entering exergy to the heating cell was increased. For that reason, exergy loss increased with decreasing salt content and voltage lean. From a thermodynamic standpoint, the exergy loss improved when the heat boundary with the heating system is higher than the ambient heat (Darvishi ainsi que al., 2015, Corzo ou al., 2008). Thus, elimination of heat transfer across the border of the program could decrease the exergy reduction. It is not suggested using from the aluminum metal as a great electrode pertaining to ohmic concentration/evaporation processes due to the higher exergy consumption and lower exergy efficiency as compared with 316L St and Br electrodes at the same heating conditions.
Determine (5) demonstrates that the IP increased with increasing of voltage lean and salt content. Actually the IP is the maximum useful exergy which can be assimilated from the exergy loss and increased the exergy performance of procedure by applying a few changes in the first system just like isolation of cell wall, selection of suitable electrode, and applied the power out of cell by simply water steam for preheating of clean product. The IP of control examples varied among 2 . 37 ” a few. 64 (MJ/kg water evp) for Br electrode, installment payments on your 89 ” 3. 75 (MJ/kg drinking water evp) intended for 316L Street electrode, and 2 . 94 ” some. 68 (MJ/kg water evp) for Approach electrode. When these values at 2% w/w salt content varied between 1 ) 99 ” 2 . 81 (MJ/kg water evp), 1 . 86 ” 2 . sixty-eight (MJ/kg drinking water evp), and 2 . 39 ” a few. 98 (MJ/kg water evp) for Br, 316L Saint, and Ing electrodes, correspondingly. Also, the IP values of 316L St and Br electrodes are less than that identified for ‘s electrode exact same heating conditions.
Maximum improvement potential could be assessed and structural inefficiencies become noticeable, which might bring about interests in process innovative developments. The effect of salt content material, electrode type, and volts gradient examined on exergy aspects of ohmic tomato insert production, and found as: Energy efficiency improved with increasing salt articles and voltage gradient. Applied of Approach electrode improved the exergy consumption than Br and 316L Saint electrodes. There is not any significant difference among exegy facets of Br and 316L Saint electrodes. Exergy loss substantially decreased with increasing volt quality gradient and salt content (p<, 0. 05). The minimum improvement potential was obtained 1 ) 86 MJ/kg water in 2% (w/w) and 14 V/cm to get 316L Street electrode.
