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Effects of Sulphurization Duration of Doses and Cold Storage on SO2 Content of Dried Apricot Fruits of cv. ‘Hacihaliloglu’  [cached]
Kadir OZTURK,Ramazan KONAK,Bulent OZTURK,Salih ATAY
Notulae Botanicae Horti Agrobotanici Cluj-Napoca , 2011,
Abstract: The study was carried out between 2004 and 2005 years in Malatya Fruit Research Institute. The fumigation of 1600, 1800 or 2000 g SO2 were applied for 6, 8, 10, 12 and 24 hr after harvest on dried ‘Hacihaliloglu’ apricot fruits. The loss of SO2, product moisture (%), product temperature, acidity (%), pH and the colour of the apricot fruits were determined after the drying processes on the wooden trays following the SO2 fumigation and during storage periods. The results showed that the average level of the SO2 in the dried apricots was found as 2000 ppm after fumigation as requirement of European regulations. Dried apricot fruits had 2174 ppm of SO2 in 2004 and 1586 ppm of SO2 in 2005 at the beginning of storage and these amounts were decreased to 1284 and 1091 ppm at the end of 12 months of storage in normal atmospheric conditions. The loss of SO2 amount in dried apricots was found to be directly proportional with the initial quantity of SO2. When the level of SO2 in dried apricots was decreased to 1500 ppm, the quality of the product was also decreased and the colour of dried apricots are darkened. As a result of this study, can be recommended that the dried apricots including 2000 ppm SO2 should be marketed after 6 months of storage.
Osmotic Drying of Apricot (Prunus armeniaca) in Sucrose Solution
Ivan Pavkov,Ljiljana Babi?,Mirko Babi?,Milivoj Radoj?in
Agriculturae Conspectus Scientificus (ACS) , 2009,
Abstract: Osmotic drying is a process of partial removal of water by submersing fruits in sucrose solution. The goal of this paper is to examine kinetic features of osmotic drying of apricot halves in sucrose solution. For osmotic drying of apricot halves in a thick immovable layer, a planned experiment was conducted. Experimental results were used to create an empirical model of osmotic drying kinetics which expresses the influence of analyzed experiment factors on water loss (WL). The experiment factors were temperature of osmotic solution, varied at two levels, 35 °C and 60 °C, and sucrose concentration varied at two levels, 50 °Bx and 65 °Bx. Using regression analysis of experimental data for water loss (WL) at statistical probability of 99 %, parameters of empirical model and correlation coefficient were calculated for the proposed mathematical model. Experimental results were approximated using the derived equation. Conformance of experimental results with the empirical model was evaluated using correlation coefficient (R). Correlation coefficient calculated for the proposed model was high, R = 0.976. It indicates fi ne agreement between experimental and model values for water loss.
Delaying Apricot (cv. Shahroudi) Flower Induction by Growth Regulators Application
E. Ganji Moghadam,A. Mokhtarian
Journal of Applied Sciences , 2006,
Abstract: Control flowering time in apricot trees is very important where spring frost damage is of high risk. Application of plant growth regulators during autumn has been suggested for controlling bloom date. This experiment was conducted during 2000-2001 to examine the effects of application of different concentrations of ethephon and gibberellic acid (0, 50, 100, 200 and 300 mg L-1) at the end of August, September and October) to delay flowering in apricot Shahroudi cultivar. A factorial experiment was laid out in Completely Randomized Block Design with 3 replications. Compared to the control results showed, 100 mg L-1 of ethephon applied at the end of October delayed full bloom approximately 3 days (2000) and 7 days (2001). Gibberellic acid applied at 300 mg L-1 at the end of August delayed full bloom about 5 days (2000) and at the end of September, l0 days (2001). During both year`s gibberellic acid and ethephon applied at the higher concentrations resulted lower percentages of flower opening and fruit set.
Application of pulse combustion technology in spray drying process
Zbicinski, I.;Smucerowicz, I.;Strumillo, C.;Crowe, C.;
Brazilian Journal of Chemical Engineering , 2000, DOI: 10.1590/S0104-66322000000400009
Abstract: the paper presents development of valved pulse combustor designed for application in drying process and drying tests performed in a specially built installation. laser technique was applied to investigate the flow field and structure of dispersed phase during pulse combustion spray drying process. pda technique was used to determine initial atomization parameters as well as particle size distribution, velocity of the particles, mass concentration of liquid phase in the cross section of spray stream, etc., in the drying chamber during drying tests. water was used to estimate the level of evaporation and 5 and 10% solutions of sodium chloride to carry out drying tests. the computational fluid dynamics technique was used to perform theoretical predictions of time-dependent velocity, temperature distribution and particle trajectories in the drying chamber. satisfactory agreement between calculations and experimental results was found in certain regions of the drying chamber.
Application of pulse combustion technology in spray drying process  [cached]
Zbicinski I.,Smucerowicz I.,Strumillo C.,Crowe C.
Brazilian Journal of Chemical Engineering , 2000,
Abstract: The paper presents development of valved pulse combustor designed for application in drying process and drying tests performed in a specially built installation. Laser technique was applied to investigate the flow field and structure of dispersed phase during pulse combustion spray drying process. PDA technique was used to determine initial atomization parameters as well as particle size distribution, velocity of the particles, mass concentration of liquid phase in the cross section of spray stream, etc., in the drying chamber during drying tests. Water was used to estimate the level of evaporation and 5 and 10% solutions of sodium chloride to carry out drying tests. The Computational Fluid Dynamics technique was used to perform theoretical predictions of time-dependent velocity, temperature distribution and particle trajectories in the drying chamber. Satisfactory agreement between calculations and experimental results was found in certain regions of the drying chamber.
KINETICS OF APRICOT THIN LAYER DRYING IN A MIXED AND INDIRECT MODE SOLAR DRYER  [cached]
Ghatrehsamani S.H., Dadashzadeh M. And Zomorodian A.
International Journal of Agriculture Sciences , 2012,
Abstract: This paper presents mathematical modeling of a thin layer solar drying process of apricots. A forced convection mixed and indirect mode cabinet solar dryer (total collector surface area of 4m2 and total tray surface area of 0.7m2) was employed. Each experiment started from 9:00 to18:00 on sunny days in summer. The experiments were conducted at three air flow temperatures of 40, 50 and 60 oC with three air flow rates of 8.7, 6.3 and 3.8 m/s respectively for each indirect and mixed mode dryer types. The solar intensity was measured and recorded from 420 to 1000 W/m2 during the course of experiments. In order to select the most appropriate drying model equation in each mode of drying, 10 different models were examined using the thin layer drying experimental data. The results of curve fitting were validated by comparing the proper statistical coefficients namely: r, χ 2, RMSE using non-linear regression analysis. According to the results, two-term drying model could satisfactorily describes the solar thin layer drying behavior of apricots with correlation coefficient (r) of 0.999 for both types of solar drying with χ2=3.374*10-3, RMSE=4.33*10-2 for the mixed-mode and χ 2=1.243*10-4, RMSE=8.64*10-3 for the indirect mode respectively. The effect of drying operating conditions (air temperature and velocity) on the model constants and coefficients were also investigated using multiple regression analysis.
OPTIMIZING AIRFLOW REVERSALS FOR KILN DRYING OF SOFTWOOD TIMBER BY APPLYING MATHEMATICAL MODELS
Pang,Shusheng;
Maderas. Ciencia y tecnología , 2004, DOI: 10.4067/S0718-221X2004000200001
Abstract: after experimental validation of a kiln-wide drying model, a single board drying model and a stress model for kiln drying of softwood timber, these models are integrated and used to investigate benefits of airflow reversals in smoothing moisture content distribution and in reducing drying stresses for commercial kiln drying. in the current study, a high temperature drying schedule (db/wb of 120/70°c and air velocity of 5 m/s) was simulated and 5 strategies for airflow reversal were evaluated. these strategies are: airflow reversal every hour; airflow reversal every 2 hours; airflow reversal every 3 hours and airflow reversal after 2 and 10 hours of drying. the results are compared to ?control? in which airflow is unidirectional (no reversal). it has been found that, for the moisture content distribution, the first reversal is critical and frequencies of subsequent flow reversals can be varied depending on the drying temperature used. however, more frequent airflow reversal has benefits in reducing drying stresses. these findings are consistent with observations in commercial kiln drying of softwood lumber
OPTIMIZING AIRFLOW REVERSALS FOR KILN DRYING OF SOFTWOOD TIMBER BY APPLYING MATHEMATICAL MODELS
Shusheng Pang
MADERAS : Ciencia y Tecnología , 2004,
Abstract: After experimental validation of a kiln-wide drying model, a single board drying model and a stress model for kiln drying of softwood timber, these models are integrated and used to investigate benefits of airflow reversals in smoothing moisture content distribution and in reducing drying stresses for commercial kiln drying. In the current study, a high temperature drying schedule (DB/WB of 120/70°C and air velocity of 5 m/s) was simulated and 5 strategies for airflow reversal were evaluated. These strategies are: airflow reversal every hour; airflow reversal every 2 hours; airflow reversal every 3 hours and airflow reversal after 2 and 10 hours of drying. The results are compared to ‘Control’ in which airflow is unidirectional (no reversal). It has been found that, for the moisture content distribution, the first reversal is critical and frequencies of subsequent flow reversals can be varied depending on the drying temperature used. However, more frequent airflow reversal has benefits in reducing drying stresses. These findings are consistent with observations in commercial kiln drying of softwood lumber
Application of High Power Ultrasound in Drying of Fruits and Vegetables
Re?ek Jambrak, A,Lelas, V.,Herceg, Z.,Badanjak, M.
Kemija u Industriji , 2010,
Abstract: Ultrasound is a sound frequency in the range between 18 and 100 kHz that is above hearing of the human ear. High power ultrasound means application of intensities higher than 1 W cm–2 (usually in the range between I=10–1000Wcm–2). High power and low frequency ultrasound (f = 20 to 100 kHz) is considered as “power ultrasound” because its application causes cavitation and is applied in the food industry. High power ultrasound is applied for degassing of liquid food, for induction of oxidation/reduction reactions, for extraction of enzymes and proteins, for inactivation of enzymes and induction of nucleation for crystallization. Ultrasound is anticipating heat transfer; it is used for emulsifying, sterilization, extraction, degassing, filtrating, drying and induction of oxidation. Conventional hot air drying is a very energy- and cost-intensive process. Drying is a simultaneous operation of heat and mass exchange that is followed by phase changes. Application of different pretreatments, like osmotic dehydration, ultrasound and ultrasound assisted osmotic dehydration has shown different effects on fruits and vegetables. When the high intensity acoustic energy is passing through solid material, it causes several fast and successive compressions and rarefactions with speeds that depend on the frequency applied. Thus, material is exposed to a series of exchangeable squeezing and relaxations, very like continuous squeezing and releasing of the sponge. This mechanism known as "rectified diffusion" is very important in acoustic drying and migration of water. Application of ultrasound as a pretreatment has shown great influence on reducing afterward hot air drying thereby reducing total drying time. It is also shown that pretreatment before drying facilitates better mass transfer and water diffusivity than osmotic dehydration. Quality of the product after drying is better because ultrasound pretreatment is applied at room temperature thus reducing deteriorating alterations and nutritive loss of compounds in fruits and vegetables.In this paper, the basic theory of ultrasound has been described. In the figures, the range of sound by frequency is described, as is the amplitude of ultrasound and its effect on the material also l, the wavelength and attenuation coefficient have been explained. The most common usage of power ultrasound as probe type of high intensity ultrasound set system with piezoelectric transducer have been introduced as a system for ultrasound drying. When the ultrasound wave passes through material the basic effect occurs. It is called cavitation a
Dynamics of SO2 absorption by sewage sludge during drying
接触式污泥干化过程中SO2吸收率的动态变化

WENG Huanxin,FENG Xi,SU Minhu,ZHANG Jinjun,MA Xuewen,
翁焕新
,冯曦,苏闽华,章金骏,马学文

环境科学学报 , 2010,
Abstract: Using the actual operating parameters of a contact-type sludge drying process, a simulation was conducted to study the dynamics of absorption of suffur dioxide (SO_2) from flue gas by sewage sludge during drying. The factors and causes leading to changes in the absorption rate were analyzed. The results show that the SO_2 absorptian rate decreased with increasing temperature and airflow. At 80℃, the SO_2 absorption rates of sludge with moisture contents of 55% and 75% , were 16.0% and 25.0% respectively. These rates were reduced to 6.0% and 7.0% , respectively, at 160℃. Absorption of SO2 by sludge occurs when SO_2 gas diffuses from the gas phase to the gas-liquid interlace, so elevating the drying temperature and increasing the airflow accelerate the evaporation of sludge water, thus hampering the process and causing the SO_2 absorption rate to drop. Increase of the SO_2 concentration in the flue gas had no obvious effect on SO_2 absorption rate. After absorption of SO_2 , the pH of the sludge dropped, indicating that acidic reactions had occurred. Infrared analysis of the sludge shows that absorption of SO2 by sludge is a chemical absorption process.
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