The characterization of suspension/emulsion sprays plays a decisive role in many industrial processes. A good example of such a process is the drying of a milk spray to produce milk powder, where the process efficienc...The characterization of suspension/emulsion sprays plays a decisive role in many industrial processes. A good example of such a process is the drying of a milk spray to produce milk powder, where the process efficiency and product quality is typically controlled by atomization parameters like flow rate, pressure, etc.. However, these parameters influence directly the droplet size and droplet velocity distributions in a spray, so that optimizing a spray drying process often involves adjusting the spray to a desired droplet size and droplet velocity distribution. This requires a measurement technique capable of characterizing in real time, the droplets in a suspension/emulsion spray. To achieve this aim, we present developments to the well-known time-shift technique for spray measurements.展开更多
This paper focuses on the drying characteristic of anchovy fish （Anchovia engraulidae）. It is necessary to understand the drying behavior, quality of the products and time required to optimize the energy consumption...This paper focuses on the drying characteristic of anchovy fish （Anchovia engraulidae）. It is necessary to understand the drying behavior, quality of the products and time required to optimize the energy consumption of the process. The optimum velocity and temperature of drying air for good quality dried anchovy fish was determined. In average, the fish are 7 cm in length and 3.0-3.5 g in mass. Although some research on fish drying has been done, the study of drying of anchovy fish and its characteristic has not been well reported. The fish to be dried were arranged on 15 × 15 cm2 tray in the drying chamber of 17 × 30 cm2. The hot air of 40 -70 ℃ was delivered parallel to the tray with the velocity of 0.6 and 0.9 m s-1. It is found that thermal conductivity （k） and specific heat （cp） of anchovy fish are function of the moisture content （MC）. The higher moisture content results in higher thermal conductivity and specific heat. Critical water content is also found in this experiment as well as the optimum drying condition. Drying rate period of anchovy fish will change from the constant drying rate period to the falling drying rate period when critical moisture content is about 48.8%-50.3% （wet basis）. At these experiments, there is no case-hardening, even at temperature of 70 ℃. To achieve the optimum result, the drying process should be implemented in three steps, drying process at 70 ℃ for 150 min followed by drying at 50℃ for 100 min, and finally drying at 40℃ till achieving equilibrium moisture content. This research will contribute to improvement of drying method to achieve good quality of dried fish.展开更多
This paper considers the combination of hydrothermal degradation （HTD） and superheated steam （SHS） drying in disposal and processing of degradable organic wastes in municipal solid wastes （MSW）. In SHS drying, a...This paper considers the combination of hydrothermal degradation （HTD） and superheated steam （SHS） drying in disposal and processing of degradable organic wastes in municipal solid wastes （MSW）. In SHS drying, a fraction of dryer thermal energy input can be recovered and used to satisfy the heat requirement in maintaining the HTD operating temperature. Both energy and exergy analysis are applied to the combined process. The analysis covers ranges of dryer inlet temperatures of 202.38-234.19~C and feed water content of 32.5-65%. Thermal energy analysis shows that the combination of HTD and SHS drying can achieve thermal energy self-sufficiency （TES） by manipulating process variables. The exergy analysis indicates the location, type, and magnitude of the exergy losses during the whole process by applying the second law of thermodynamics.展开更多
OBJECTIVE： To study the effects of the drying processing in terms operational parameters on the bio- active constituents of six YuanzhJ （Radix Palygalae） samples across China. METHODS： Six Yuanzhi （Radix Palygala...OBJECTIVE： To study the effects of the drying processing in terms operational parameters on the bio- active constituents of six YuanzhJ （Radix Palygalae） samples across China. METHODS： Six Yuanzhi （Radix Palygalae） samples were investigated using thermogravimetry analysis. The heating courses were set in two ways： the temperature-programmed process from room temperature to 150℃ ,and the constant-temperature course at 50℃, 70℃ and 90℃. RESULTS： The peak temperature of six Yuanzhi （Radix Palygalae） samples ranged from 78℃ to 88℃. The mass loss rate of Yuanzhi （Radix Palygalae） alcohol-soluble extract was significantly increased when heated at 90℃. Four types of bioactive ingredients were detected in volatile oils of Yuanzhi （Radix Palygalae） sample from Shanxi province by Gas Chromatography-mass spectrometry analysis. Fourier Transform Infrared Spectroscopy results showed that the drying temperature exerted a great influence on types and amount of ingredients of Yuanzhi （Radix Palygalae）. The kinetic study showed that the constant-temperature drying process of Yuanzhi Radix Palygalae） samples could be well de- scribed by the Page Model, especially for the drying process at 50~C, in which R2 and SD values were more than 0.98 and less than 0.04, respectively.The drying constant k of three Yuanzhi （Radix Palygalae） samples from Shanxi, Gansu and Shaanxi provinces in China was corresponding to the Arrhenius equation, and their activation energies were 28.07, 2.5.38 and 21.48 kJ/mol, respectively. CONCLUSION： The drying process of Yuanzhi （Radix Palygalae） was very important for bioactive ingredients improvement in Yuanzhi （Radix Palygalae）. Temperature was a thermodynamic property significantly affecting the process.展开更多
文摘The characterization of suspension/emulsion sprays plays a decisive role in many industrial processes. A good example of such a process is the drying of a milk spray to produce milk powder, where the process efficiency and product quality is typically controlled by atomization parameters like flow rate, pressure, etc.. However, these parameters influence directly the droplet size and droplet velocity distributions in a spray, so that optimizing a spray drying process often involves adjusting the spray to a desired droplet size and droplet velocity distribution. This requires a measurement technique capable of characterizing in real time, the droplets in a suspension/emulsion spray. To achieve this aim, we present developments to the well-known time-shift technique for spray measurements.
文摘This paper focuses on the drying characteristic of anchovy fish （Anchovia engraulidae）. It is necessary to understand the drying behavior, quality of the products and time required to optimize the energy consumption of the process. The optimum velocity and temperature of drying air for good quality dried anchovy fish was determined. In average, the fish are 7 cm in length and 3.0-3.5 g in mass. Although some research on fish drying has been done, the study of drying of anchovy fish and its characteristic has not been well reported. The fish to be dried were arranged on 15 × 15 cm2 tray in the drying chamber of 17 × 30 cm2. The hot air of 40 -70 ℃ was delivered parallel to the tray with the velocity of 0.6 and 0.9 m s-1. It is found that thermal conductivity （k） and specific heat （cp） of anchovy fish are function of the moisture content （MC）. The higher moisture content results in higher thermal conductivity and specific heat. Critical water content is also found in this experiment as well as the optimum drying condition. Drying rate period of anchovy fish will change from the constant drying rate period to the falling drying rate period when critical moisture content is about 48.8%-50.3% （wet basis）. At these experiments, there is no case-hardening, even at temperature of 70 ℃. To achieve the optimum result, the drying process should be implemented in three steps, drying process at 70 ℃ for 150 min followed by drying at 50℃ for 100 min, and finally drying at 40℃ till achieving equilibrium moisture content. This research will contribute to improvement of drying method to achieve good quality of dried fish.
文摘This paper considers the combination of hydrothermal degradation （HTD） and superheated steam （SHS） drying in disposal and processing of degradable organic wastes in municipal solid wastes （MSW）. In SHS drying, a fraction of dryer thermal energy input can be recovered and used to satisfy the heat requirement in maintaining the HTD operating temperature. Both energy and exergy analysis are applied to the combined process. The analysis covers ranges of dryer inlet temperatures of 202.38-234.19~C and feed water content of 32.5-65%. Thermal energy analysis shows that the combination of HTD and SHS drying can achieve thermal energy self-sufficiency （TES） by manipulating process variables. The exergy analysis indicates the location, type, and magnitude of the exergy losses during the whole process by applying the second law of thermodynamics.
基金Supported by the National Science and Technology Support Program of the Ministry of Science and Technology of the People's Republic of China (No.2011BAI07B05)Shanxi Science and Technology Tackling Fund (No.20100311090,20130313015-2)Department of Health of Shanxi province Tackling Fund (No.200834)
文摘OBJECTIVE： To study the effects of the drying processing in terms operational parameters on the bio- active constituents of six YuanzhJ （Radix Palygalae） samples across China. METHODS： Six Yuanzhi （Radix Palygalae） samples were investigated using thermogravimetry analysis. The heating courses were set in two ways： the temperature-programmed process from room temperature to 150℃ ,and the constant-temperature course at 50℃, 70℃ and 90℃. RESULTS： The peak temperature of six Yuanzhi （Radix Palygalae） samples ranged from 78℃ to 88℃. The mass loss rate of Yuanzhi （Radix Palygalae） alcohol-soluble extract was significantly increased when heated at 90℃. Four types of bioactive ingredients were detected in volatile oils of Yuanzhi （Radix Palygalae） sample from Shanxi province by Gas Chromatography-mass spectrometry analysis. Fourier Transform Infrared Spectroscopy results showed that the drying temperature exerted a great influence on types and amount of ingredients of Yuanzhi （Radix Palygalae）. The kinetic study showed that the constant-temperature drying process of Yuanzhi Radix Palygalae） samples could be well de- scribed by the Page Model, especially for the drying process at 50~C, in which R2 and SD values were more than 0.98 and less than 0.04, respectively.The drying constant k of three Yuanzhi （Radix Palygalae） samples from Shanxi, Gansu and Shaanxi provinces in China was corresponding to the Arrhenius equation, and their activation energies were 28.07, 2.5.38 and 21.48 kJ/mol, respectively. CONCLUSION： The drying process of Yuanzhi （Radix Palygalae） was very important for bioactive ingredients improvement in Yuanzhi （Radix Palygalae）. Temperature was a thermodynamic property significantly affecting the process.
