Drying Model of Paste Materials in Fluidized Bed with Inert Particles and Immersed Heating Tubes

2011 ◽  
Vol 412 ◽  
pp. 463-468
Author(s):  
Bi Qiang Yao ◽  
Xue Jun Zhu
Keyword(s):  
Fluidized Bed ◽  
High Viscosity ◽  
Water Evaporation ◽  
Low Dissipation ◽  
Inert Particles ◽  
Drying Technology ◽  
Drying Properties ◽  
Drying Conditions ◽  
Drying Efficiency ◽  
Equipment Size

The mechanism of drying paste materials was investigated in a fluidized bed with inert particles and inner heats. A mathematical model is proposed to predict the specific water evaporation. The drying properties of dryer can be predicted based on the correlation equations. The drying of paste CaCO3materials was industrial-mode experimentally carried out in a fluidized bed with inert particles and immersed heating tubes. The paste material was spray droplet in sizes range of 200~400μm with pressure nozzles or air-blast nozzles, and spray to the surface of inert particles, and the feasible drying conditions were researched. The feasible drying parameters, operation parameters and equipment parameters were researched. The results show that this drying technology can be enhanced the heat transfer and the paste materials of high viscosity can be effectively distributed into the fluidized bed, well distributed temperature in beds, large elasticity of operation, the low energy consumption. The new drying equipment has high drying capacity, small equipment size. The results can provide important meaning on theory and instructing practice for developing the new drying technology with high drying efficiency and low dissipation of energy.

scholarly journals Drying of suspension and pastes in fluidized bed of inert particles

2000 ◽  
Vol 65 (12) ◽  
pp. 963-974 ◽  
Author(s):  
Zeljko Grbavcic ◽  
Zorana Arsenijevic ◽  
Radmila Garic-Grulovic
Keyword(s):  
Pure Water ◽  
Operating Conditions ◽  
Raw Material ◽  
Water Evaporation ◽  
Large Temperature ◽  
Attractive Alternative ◽  
Mechanical Agitation ◽  
Inert Particles ◽  
Fluid Bed ◽  
Drying Efficiency

A fluid bed dryer with inert particles was used for the drying of suspensions and pastes. The effects of the operating conditions on the dryer throughput and on the product quality were investigated. Experiments were performed in a cylindrical column 215 mm in diameter and 1200 mm in height with 0.925 mm diameter glass spheres as the fluidizing media. Cineb fungicide, copper hydroxide and pure water were used as the feed material. With respect to the main efficiency criteria, i.e., specific water evaporation rate, specific heat consumption and specific air consumption, a fluid bed dryer with inert particles represents a very attractive alternative to other drying technologies. A high drying efficiency results from the large contact area and from the large temperature difference between the inlet and outlet air. A rapid mixing of the particles, due to aggregative fluidization and mechanical agitation, leads to nearly isothermal conditions throughout the bed. In our experiments, suspensions and very dense pastes were successfully treated. Suspension and product hold-up in the bed varies between 6 and 8 % by mass and a product with the same particle size as the raw material is obtained.

scholarly journals Performances of continuous dryer with inert medium fluidized bed

2008 ◽  
Vol 62 (1) ◽  
pp. 13-24
Author(s):  
Zorana Arsenijevic ◽  
Zeljko Grbavcic ◽  
Radmila Garic-Grulovic
Keyword(s):  
Specific Heat ◽  
Fluidized Bed ◽  
Temperature Difference ◽  
Evaporation Rate ◽  
Operating Conditions ◽  
Heat Consumption ◽  
Water Evaporation ◽  
Isothermal Conditions ◽  
Inert Particles ◽  
Fluid Bed

A fluid bed dryer with inert particles represents a very attractive alternative to other drying technologies according to the main efficiency criteria, i.e. specific water evaporation rate, specific heat consumption and speci?fic air consumption. A high drying efficiency results from the large con?tact area and from the large temperature difference between the inlet and outlet air. A rapid mixing of the particles leads to nearly isothermal conditions throughout the bed. A fluid bed dryer with inert particles was used for drying of slurries. Experiments were performed in a cylindrical column 215 mm in diameter with glass spheres as inert particles. In this paper, results of drying experi?ments with slurries of Zineb fungicide, copper hydroxide, calcium carbo?nate and pure water used as the feed material are presented. In our fluidized bed we successfully dried a number of other materials such as: fungicides and pesticides (Ziram, Propineb, Mangozeb, copper oxy-chloride, copper oxy-sulphate, Bordeaux mixture), other inorganic compounds (calcium sulphate, cobalt carbonate, electrolytic copper, sodium chloride), and a complex compound (organo-bentonite). The effects of operating conditions on dryer throughput and product quality were investigated. Main performance criteria, i.e. specific water evaporation rate, specific heat consumption and specific air consumption, were quantified. Temperature profile along the bed was mapped, and nearly isothermal conditions were found due to thorough mixing of the particles. Analysis of drying and energy efficiencies as a function of inlet and outlet air temperature difference was performed for deeper insight in dryer behavior and for optimizing dryer design and operation from an energy point of view. A simple mathematical model based on an overall heat balance predicts the dryer performance quite well. The industrial prototype with fluid bed of 0.8 m in diameter and capacity 650 kg of evaporated moisture per hour was realized on the basis of presented investigations on pilot unit. The most important results are 50% decrease in energy consumption and no-additional grinding of dried product in comparison with old tunnel drying technology.

scholarly journals High efficiency disperse dryer - an innovative process for drying of solutions, suspensions and pastes in a fluidized bed of inert particles

2019 ◽  
Vol 73 (4) ◽  
pp. 213-222
Author(s):  
Mihal Djuris ◽  
Tatjana Kaludjerovic-Radoicic ◽  
Darko Jacimovski ◽  
Zorana Arsenijevic
Keyword(s):  
Fluidized Bed ◽  
High Efficiency ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Performance Criteria ◽  
Water Evaporation ◽  
Fluidized Bed Dryer ◽  
Glass Spheres ◽  
Innovative Process ◽  
Inert Particles

In this paper, an innovative fluidized bed dryer with inert particles is presented. The system can be used for drying of solutions, suspensions and pastes in order to obtain a powdered product. The experiments were performed in a pilot-scale dryer with a cylindrical column 0.215 m in diameter and 1.2 mm height, with glass spheres as inert particles. The material used for drying was CuSO4 solution. The effects of operating conditions on the dryer throughput and product quality were investigated. Main performance criteria, i.e. specific water evaporation rate, specific heat consumption and specific air consumption, were quantified. Nearly isothermal conditions were found due to thorough mixing of the particles. The energy efficiency of the dryer was also assessed. Simple heat and mass balances predicted the dryer performance quite well.

scholarly journals Effect of Spray Dryer Scale Size on the Properties of Dried Beetroot Juice

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6700
Author(s):  
Jolanta Gawałek
Keyword(s):  
Spray Drying ◽  
Industrial Process ◽  
Laboratory Scale ◽  
Industrial Scale ◽  
Process Conditions ◽  
Spray Dryer ◽  
Beetroot Juice ◽  
Centrifugal Atomization ◽  
Drying Conditions ◽  
Drying Efficiency

Experiments detailing the spray drying of fruit and vegetable juices are necessary at the experimental scale in order to determine the optimum drying conditions and to select the most appropriate carriers and solution formulations for drying on the industrial scale. In this study, the spray-drying process of beetroot juice concentrate on a maltodextrin carrier was analyzed at different dryer scales: mini-laboratory (ML), semi-technical (ST), small industrial (SI), and large industrial (LI). Selected physicochemical properties of the beetroot powders that were obtained (size and microstructure of the powder particles, loose and tapped bulk density, powder flowability, moisture, water activity, violet betalain, and polyphenol content) and their drying efficiencies were determined. Spray drying with the same process parameters but at a larger scale makes it possible to obtain beetroot powders with a larger particle size, better flowability, a color that is more shifted towards red and blue, and a higher retention of violet betalain pigments and polyphenols. As the size of the spray dryer increases, the efficiency of the process expressed in powder yield also increases. To obtain a drying efficiency >90% on an industrial scale, process conditions should be selected to obtain an efficiency of a min. of 50% at the laboratory scale or 80% at the semi-technical scale. Designing the industrial process for spray dryers with a centrifugal atomization system is definitely more effective at the semi-technical scale with the same atomization system than it is at laboratory scale with a two-fluid nozzle.

scholarly journals Influence of drying conditions on the acacia gum particle growth in fluidized bed agglomeration: in-line monitoring of particle size

2018 ◽  
Author(s):  
Juliana G Rosa ◽  
R. F. Nascimento ◽  
K. Andreola ◽  
O. P. Taranto
Keyword(s):  
Particle Size ◽  
Fluidized Bed ◽  
Particle Growth ◽  
Spatial Filter ◽  
Important Food ◽  
Process Yield ◽  
Size Monitoring ◽  
Acacia Gum ◽  
Bed Agglomeration ◽  
Drying Conditions

Acacia gum is an important food emulsifier that presents poor instant properties which can be improved by fluidized bed agglomeration. This study investigated the influence of drying conditions on particle growth kinetics using an in-line particle size monitoring by spatial filter velocimetry. The drying conditions varied according to the binder flow rate and the fluidizing air temperature. The particle growth kinectis showed drying conditions dependence. At mild drying conditions the growth rate and the process yield were higher. The in-line particle size monitoring was useful to observe the influence of the drying conditions on the growth kinetics.Keywords: fluidized bed agglomeration; acacia gum; particle growth kinectis; in-line monitoring.  

scholarly journals Wheat Germ Drying with Different Time-Temperature Combinations in a Fluidized Bed Dryer

Processes ◽  
2018 ◽  
Vol 6 (12) ◽  
pp. 245 ◽  
Author(s):  
Der-Sheng Chan ◽  
Meng-I Kuo
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Fluidized Bed ◽  
Wheat Germ ◽  
Dynamic Equilibrium ◽  
Cooling Stage ◽  
Fluidized Bed Dryer ◽  
Drying Condition ◽  
Drying Conditions ◽  
The Mathematical Model

The development of an effective drying performance of the fluidized bed dryer (FBD) is crucial to reduce drying costs. The objective of this study was to investigate the drying performance of wheat germ (WG) with different time-temperature combinations in the FBD. The WG was dried at different set temperatures of 80, 100 and 120 °C. The moisture content (MC) and water activity (WA) of WG were measured. A mathematical model was proposed to develop an optimal drying condition. The changes in the MC of WG during drying in the FBD could be divided into the decreased period, the dynamic equilibrium period and the increased period. The product temperature of 45 °C and WA of 0.3 of WG drying could be attained by different time-temperature combinations. The mathematical model, which was developed in conjunction with different time-temperature combinations, could predict the dehydration time and the condensation time of WG for optimization the drying conditions. The WG dehydration at the heating stage and the WG condensation at the cooling stage could also be evaluated by the dehydration flux and the condensation flux, respectively. The optimal drying performance of WG exists in a compromise between promoting dehydration and reducing condensation. Information obtained from the analysis of dehydration flux and condensation flux with experimental data and simulation gave the guidelines for performing an effective drying of WG in the FBD.

Experiments on Hot-Air and Infrared Drying Characteristics of LiCoO2 Cathode Coating for Lithium-Ion Battery

2020 ◽  
Vol 1003 ◽  
pp. 260-267
Author(s):  
Xian Feng Wu ◽  
Xu Jia Li ◽  
Xin Zhi Bei
Keyword(s):  
Lithium Ion Battery ◽  
Radiation Power ◽  
Influencing Factor ◽  
Lithium Ion ◽  
Drying Time ◽  
Infrared Drying ◽  
Hot Air ◽  
Constant Rate ◽  
Drying Conditions ◽  
Drying Efficiency

Based on the drying technology principle of lithium-ion battery cathode coating, the variation law of dry base moisture content and drying rate in the process of hot-air drying and infrared drying was studied. The experimental results show that the cathode coating of lithium-ion battery dried under hot-air and infrared conditions can be divided into three stages: increasing-rate, constant-rate, and falling-rate. The constant-rate stage is the main drying stage, accounting for more than 50% of the weight loss, the falling-rate stage is the main energy consumption stage, accounting for more than 50% of the time. Under the condition of hot-air, the change level of airspeed is the main influencing factor of the drying process, and the drying time can be reduced by about 35% for each 0.7 m/s increase in airspeed. Under infrared conditions, the change level of radiation power is the main influencing factor of the drying process, and the drying time can be reduced by about 34.1% for every 100W of power increase. The optimal drying conditions under hot-air conditions are: air temperature 90 °C, airspeed 2.3 m/s; the optimal drying conditions under infrared conditions are: radiation distance 13 cm, radiation power 200 W. By comparing the best conditions of hot-air and infrared, it can be known that the drying efficiency is higher in the infrared condition and the drying duration is 160 s, but the energy utilization rate in the falling-rate stage in the infrared condition is lower than that in the hot-air condition. Therefore, when infrared drying enters the falling-rate stage, it can be supplemented by hot-air drying to further improve the drying efficiency.

Drying of Slurries in Fluidized Bed of Inert Particles

2004 ◽  
Vol 22 (8) ◽  
pp. 1793-1812 ◽  
Author(s):  
Zeljko B. Grbavcic ◽  
Zorana Lj Arsenijevic ◽  
Radmila V. Garic-Grulovic
Keyword(s):  
Fluidized Bed ◽  
Inert Particles
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