Fluidized Bed Agglomeration Research Articles

Effect of Calcium Addition on Fluidized Bed Agglomeration Caused by Potassium Phosphates

Effect of Calcium Addition on Fluidized Bed Agglomeration Caused by Potassium Phosphates

Employing a multi-resonance microwave sensor for in-line moisture monitoring of fluidized bed agglomeration

Amorphous substances are relatively common in food industry and their characteristics depend highly on the moisture content. Process parameters are adjusted based on online measurements to control the product quality of the agglomerates. This leads to two major challenges: precise moisture content measurements of amorphous particles at (i) different temperatures and for (ii) a wide moisture content range.In this study two workflows (inline fluidized bed and conditioned fixed bed) calibration of microwave sensors are compared and it is shown that for fluidized beds inline calibration is necessary to achieve accurate moisture measurements. The application of the novel microwave sensor MW 4200 working at resonance frequencies of 2.3 and 5.6 GHz is described. The temperature influence on the measurement is investigated with measurements of a fixed particle bed. Rapid, reliable in-process moisture control at a wide range of moisture contents and temperatures for agglomeration in fluidized beds, with a mean relative accuracy of 82 %, is achieved. This technology improves productivity and precision in industrial operations, minimizes waste and optimizes energy usage.

Influence of multi-factor interactions on particle growth during top-spray fluidized bed agglomeration

Considering the strong dependence of agglomerate characteristics on various operating parameters, this study employs the control variable methodology (CVM) and response surface methodology (RSM) to investigate the influence of multi-factor interactions on particle growth during top-spray fluidized bed agglomeration. First, CVM is conducted to assess the effects of individual operating parameters on the agglomerate properties, such as mean particle size, relative width, and sphericity. Then, the interactive relationship between these input variables and the quality attributes of the process is investigated using RSM. The results show that the mean particle size increases with the increase of binder viscosity and spray rate, while it decreases with the increase of fluidization gas velocity and inlet gas temperature. The relative width of the particle size distribution increases with the spray rate, binder viscosity, and fluidization gas velocity, and hardly changes with the inlet gas temperature. The mean particle size is more sensitive to the binder spray rate at a lower level of fluidization gas velocity or a higher level of inlet gas temperature. The fluidization gas velocity corresponding to the maximum D50 changes when the binder viscosity and binder spray rate are at different levels.

Improvement of powder properties of milk protein isolate by fluidised bed agglomeration with guar gum binder

A goal of this study was to investigate the influence of fluidised bed agglomeration process with guar gum (GG) binder (0–0.3%) on the physical and rheological properties of agglomerated milk protein isolate (MPI). Larger and more porous particles were formed by the agglomeration process, resulting in an improvement in powder flowability, wettability and solubility. The agglomerate with 0.1% GG binder exhibited higher viscoelastic properties than other agglomerates, with viscoelastic moduli values decreasing as the binder concentration increased (0.1–0.3%). The findings demonstrate that the agglomeration process with GG improved the powder characteristics of MPI and influenced its rheological properties.

Alkali desorption from ilmenite oxygen carrier particles used in biomass combustion

Oxygen-carrying fluidized bed materials are increasingly used in novel technologies for carbon capture and storage, and to improve the efficiency of fuel conversion processes. Potassium- and sodium-containing compounds are released during biomass combustion and may have both negative and positive effects on conversion processes. Ilmenite is an important oxygen carrier material with the ability to capture alkali in the form of titanates. This is a desirable property since it may reduce detrimental alkali effects including fouling, corrosion, and fluidized bed agglomeration. This study investigates the interactions of alkali-containing compounds with ilmenite particles previously used in an industrial scale (115 MWth) oxygen carrier aided combustion system. The ilmenite samples were exposed to temperatures up to 1000 °C under inert and oxidizing conditions while the alkali release kinetics were characterized using online alkali monitoring. Alkali desorption occurs between 630 and 800 °C, which is attributed to loosely bound alkali at or near the surface of the particles. Extensive alkali release is observed above 900 °C and proceeds during extended time periods at 1000 °C. The release above 900 °C is more pronounced under oxidizing conditions and approximately 9.1 and 3.2 wt% of the alkali content is emitted from the ilmenite samples in high and low oxygen activity, respectively. Detailed material analyses using scanning electron microscopy with energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy were conducted before and after temperature treatment, which revealed that the concentrations of potassium, sodium and chlorine decrease at the outermost surface of the ilmenite particles during temperature treatment, and Cl is depleted to a deeper level in oxidizing conditions compared to inert. The implications for ilmenite-ash interactions, oxygen carrier aided combustion and chemical looping systems are discussed.

Optimization of product characteristics of porous carbon agglomerates using a design of experiments in fluidized bed agglomeration

Spraying parameters during particle agglomeration processes can affect the agglomeration kinetics and particle growth. This study was conducted to better understand the influence of the spraying parameters in a fluidized bed wet agglomeration process, and the influence on the stability characteristics of carbon tablets. A formulation based on fine carbon and peroxide powder, as well as carboxymethyl cellulose as a binder, was used to produce agglomerates in a first production step. Thereafter in a second production step carbon tablets with a high porosity were molded for the customer goods industry. The optimization of the compressive strength of these carbon tablets was the goal of the trials. Carbon agglomerates were produced with a laboratory scale granulator called “ProCell” and were compressed with a five-cavity mechanical press. The screening of the agglomeration process parameters and their influence on the agglomerates quality, as well as the performance characteristics of the carbon tablets, were investigated using a multilevel factorial design. The experimental runs were done by varying atomized air pressure and feed rate of the fluid. This was determined by the design model. The findings of the statistical trials showed that low atomized air pressure and a low feed rate lead to a higher tablet compressive strength.

The effect of the fluidized bed agglomeration process on the powder properties of black carrot juice powders

AbstractThis study aims to apply fluidized bed agglomeration process performed at 60°C and 1.6 m/s as air temperature and velocity, to improve the powder properties of the black carrot juice powders obtained by spray drying at the inlet and outlet air temperatures of 160 and 100°C, respectively. The binders maltodextrin, gum arabic, whey protein isolate and water were added to the powders at 1:0.1, and 1:0.2 powder/binder solution (BS) ratios. The agglomerates have higher moisture content (11.35%–12.88%, wet basis) and water activity (0.256–0.379) values than the powders (9.18 ± 0.03% and 0.25 ± 0.00, respectively). While the angle of repose value of black carrot juice agglomerates decreased compared to powders, the porosity values (54.17%–66.87%) and the hygroscopic properties were improved. The friability values for the agglomerates were 37.21%–77.04%. The agglomeration process improved the microstructure, glass transition temperature and particle size distribution as determined with scanning electron microscope, differential scanning calorimeter, and laser diffraction method analysis.Practical applicationsBlack carrot is a vegetable with high nutritional value and its consumption is limited to a certain season. For this reason, the production of the powders of vegetable juices and having the agglomerated form of them, an important improvement will be achieved in the production of healthy and easy to use foods for children and adults. Fluidized bed agglomeration which is a novel application is important in the creation of easy‐to‐use meals. Black carrot juice powders could be successfully agglomerated with some different binders in fluidized beds. Powder properties of agglomerates containing water were as good as the binder agents.

Optimization of fluidized bed agglomeration process for developing a blackberry powder mixture

The research objective was to experimentally optimize the fluidized bed agglomeration process of an agglomerated blackberry powder mixture (ABPM) using the response surface methodology. As a raw material, a powdered mixture of blackberry from Castile (Rubus glaucus Benth) obtained by spray drying (SD) was used. In the evaluation of the agglomeration process, the response surface methodology was applied using a central design with a face-centered composition (α = 1), considering the independent variables: fluidisation air inlet temperature (T) (50–70 °C), the binder solution atomization air pressure (P) (1–2 bar) and process time (t) (20–35 min); and the dependent variable: moisture content (Xw), solubility (S), wettability (We), apparent density (ρa), total phenols (TP), radical scavenging (ABTS·+ and DPPH· methods), anthocyanins (Ant) (cyanidin-3-glucoside (C3G)), ellagic acid (EA) and vitamin C (Vit. C). In general, the ABPM exhibited higher porosity and particle size, which generated changes in S, We and ρa, and a better rehydration capacity of the ABPM. The optimal process conditions (T = 70 °C, P = 1.7 bar and t = 21.7 min) defined the most favourable attributes of the ABPM (Xw = 9.7 ± 0.1%, S = 74.9 ± 4.9%, We = 13.7 ± 3.6 min, ρa = 0.312 ± 0.009 g/mL, TP = 4084.6 ± 30.6 mg AGE/100g dry base (db), ABTS·+ = 4511.4 ± 124.5 mg TE/100 g db, DPPH· = 4182.7 ± 66.4 mg TE/100 g db, Ant = 213.6 ± 15.9 mg C3G/100 g db, EA = 1878.2 ± 45.9 mg/100 g db and Vit. C = 29.8 ± 7.4 mg/100 g db. The agglomeration process improved the instantaneous properties and the flow behaviour of the ABPM. Additionally, it offers significant nutritional value with potential use as an instant drink and raw material for the food industry.

The Evolution of Variance and Entropy of the Granule Size Distribution in Fluidized Bed Agglomeration

The evolution of the variance and entropy of granule size in the fluidized bed agglomeration process using two different aggregation kernels is examined. The first is a constant kernel (aggregation is independent of both time and granule size) and permits the most unconstrained agglomeration process that can occur where granules in any size class (up to a maximum size) can be formed at any point in time. This gives the fastest and largest increase in the variance and entropy of the resulting granule size distribution. The second kernel is a mechanistic kernel including a granule growth-limiting mechanism, in this case implemented by the consideration that not all collisions result in coalescence. This markedly changes the evolution of the variance and entropy of the distribution and reduces both significantly. Quantifying the entropy of the distribution provides another perspective on the change in the size distribution in an agglomeration process. It is shown that entropy can provide a better measure of size evolution than variance in that it represents the changing shape of the distribution more closely.

Statistical Investigation of Rotary Fluidized Bed Agglomeration Process with Tangential Spray and In-Line Particle Size Measurement for PAT Process Control

A statistical design of experiments for a rotary fluidized bed agglomeration process is performed to improve both the knowledge of the process and the influence of the process parameters. Agglomerates of a pharmaceutical formulation are manufactured in a laboratory fluidized bed rotor apparatus with a tangential spray nozzle. Particle size is measured in-line over the entire agglomeration process with a spatial filter velocimetry probe installed directly in the process chamber and off-line with dynamic image analysis for comparison. The influence of the process parameters spray rate, spray pressure, rotor speed, and process air temperature on the fluidized bed is investigated using a central composite design. In-line measurement of particle size is possible over the entire rotor process. Spray pressure, spray rate, square of process air temperature, and some interactions proved to be statistically significant. Particle size measured with spatial filter velocimetry and dynamic image analysis indicates good agreement and a similar trend. The successful application of particle size measurement in a fluidized bed rotor agglomeration at a laboratory scale using spatial filter velocimetry to improve process control and reduce the risk of failed batches serves as the basis for transferring to a production scale.

Particle Agglomeration and Properties of Pregelatinized Potato Starch Powder

Pregelatinized starches are used as thickeners in many instant food products. The unique properties of pregelatinized starches, such as their dispersibility in water and high viscosity, are generally desirable for instant food products. However, powdered starches cannot be easily dispersed in cold water due to clumping. The most reliable method to solve this problem is particle size enlargement by an agglomeration technique that causes a structural change in the starch. In this study, pregelatinized potato starch powder (PPSP) was agglomerated in a fluidized bed agglomerator, after which the physical, structural, and rheological properties of the PPSP agglomerated with different maltodextrin (MD) binder concentrations were investigated. The powder solubility and flowability (CI and HR) of all the agglomerated PPSPs were improved, and the particle size (D50) tended to increase as the MD concentration increased, except for the control (0% MD) and the 40% MD. The changes in the particle size of the agglomerated PPSPs were consistent with the SEM image analysis. The magnitudes of the gel strength and viscoelastic moduli (G' and G″) of the agglomerated PPSPs with 10% MD were higher than those of the control due to the more stable structure formed by better intermolecular interaction in the starch and MD during the agglomeration process. Therefore, our results indicated that the fluidized bed agglomeration process and the MD addition as a binder solution greatly influence the physical, structural, and rheological properties of PPSP.

Effect of Fluidized Bed Agglomeration on Rheological and Physical Properties of Soy Protein-Enriched Milk Powder for Dietary Supplementation in Sarcopenia.

Recently, many elderly people in Korea have been consuming protein-enriched milk powders for dietary supplementation in sarcopenia. In general, protein powders are manufactured using a spray dryer, and their fine particles result in poor instant properties. Fluidized bed agglomeration (FBA) is an effective method for improving the physical properties of protein powders via particle granulation, such as flowability and wettability. Therefore, the effects of FBA on the rheological and physical properties of isolated soy protein (ISP)-enriched skim milk powder (SMP) were investigated in this study. The size of ISP-enriched SMP particles was significantly increased by FBA, leading to changes in the Carr index and Hausner ratio from fair flowability and intermediate cohesiveness to good flowability and low cohesiveness, respectively. The wettability of the granulated particles was also improved by FBA, and they exhibited a shorter wetting time below 10 s. However, a slight color change was observed after the FBA process. These findings contribute to the production of protein-enriched food powders with improved properties.

Fluidised bed agglomeration of strawberry powder mix obtained for spray drying

BACKGROUND: The microencapsulation process using spray drying (SD) represents an effective alternative in protecting the active components present in strawberries. However, microcapsules of strawberry powder mixtures present problems of instantanisation and flowability; an aspect that can be solved by agglomeration of the particles. OBJECTIVE: The aim of this study was to evaluate the influence of the fluidised bed agglomeration process on the flow, instantaneity and antioxidant properties of strawberry powder obtained by SD. METHODS: The response surface methodology (RSM) was used with a centred composite central design (α=1), considering the factors: fluidisation air temperature (50-70°C), time (30-50 min) and atomisation air pressure of the binder agent (1-2 bar). RESULTS: An increase in particle size was observed in the agglomeration process; the agglomerated particles showed a decrease in wetting time, the agglomerates of strawberry powder mixtures presented excellent instantanisation and fluidity, solving the problems identified in the microcapsules obtained by SD. CONCLUSIONS: Although the moisture and aw levels were increased in the agglomeration process, the values are within the microbiological and physicochemical food safety range; moreover, there was no effect on the phenol content and antioxidant capacity. The experimental optimisation achieved desirability of 68.4%, the optimum conditions being 70°C, 30 min and 1 bar.

Agglomeration of Spray-Dried Milk Powder in a Spray Fluidized Bed: A Morphological Modeling

The type of solid substrate plays a critical role in determining the kinetics of the spray fluidized bed (SFB) agglomeration process. In the case of porous (also soft) primary particles (PPs), droplet aging is due to imbibition and drying. The surface properties of the substrate also change due to imbibition. The focus of the present work is to simulate the agglomeration of the spray-dried milk powder using the Monte Carlo (MC) method coupled with a drying-imbibition model. In order to extract the morphology of the formed agglomerates, an aggregation model is employed. Further, this aggregation model is employed to predict the number of positions on the PPs (later agglomerates) for droplet deposition; previously, the ‘concept of positions’ was used. The transient growth of different milk powders (whole and skim) is depicted using the enhanced MC model. The enhancement in the droplet deposition model had a prominent influence on the overall kinetics of agglomeration. As expected, this enhanced MC model predicted that the agglomeration rate of skim milk powder is higher than that of whole milk powder.

Co-processed tablet excipient composition, its preparationand use: US10071059 B2: patent spotlight.

Co-processing involves the incorporation of one excipients into the particle structure of other excipients to overcome the deficiencies of each excipients. The current patent describes the co-processing of microcrystalline cellulose and mannitol via fluid bed agglomeration with an aim to limit the use of lubricant in tablet composition. The co-processed excipients blend was compared with the physical blend of excipients and characterized for scanning electron microscopy, disintegration and hardness. The average particle size of co-processed excipients was less than 0.55mm, characterized by large individual lactose-coated particles whereas, the physical blend particles are uncoated and irregular in shape. Tablets made from both physical blend and co-processed excipients were compared. As per the hardness and disintegration studies, with increase in mixing time of excipients both hardness and disintegration time decreases.

Improved Flowability and Wettability of Whey Protein-Fortified Skim Milk Powder via Fluidized Bed Agglomeration.

Recently, protein-fortified milk powders are being widely consumed in Korea to prevent sarcopenia, and the demand for high-protein food powders is continuously increasing in the Korean market. However, spray-dried milk proteins have poor flowability and wettability owing to their fine particle sizes and high inter-particle cohesive forces. Fluidized bed agglomeration is widely used to improve the instant properties of food powders. This study investigated the effect of fluidized bed agglomeration on whey protein isolate (WPI)-fortified skim milk powder (SMP) at different SMP/WPI ratios. The fluidized bed process increased the particle size distribution, and agglomerated particles with grape-like structures were observed in the SEM images. As the size increased, the Carr index (CI) and Hausner ratio (HR) values of the agglomerated WPI-fortified SMP particles exhibited excellent flowability (CI: <15) and low cohesiveness (HR: <1.2). In addition, agglomerated WPI-fortified SMP particles exhibited the faster wetting time than the instant criterion (<20 s). As a result, the rheological and physical properties of the WPI-fortified SMP particles were effectively improved by fluidized bed agglomeration. However, the fluidized bed agglomeration process led to a slight change in the color properties. The CIE L* decreased, and the CIE b* increased because of the Maillard reaction. The apparent viscosity (ηa,10) and consistency index (K) values of the rehydrated solutions (60 g/180 mL water) increased with the increasing WPI ratio. These results may be useful for formulating protein-fortified milk powder with better instant properties.

Optimization of fluidized bed agglomeration process of a pineapple powder mixture using a binder solution of ginger extract and vitamin C

The aim of this research was to optimize fluidized bed agglomeration process of a pineapple powder mixture using a binder solution of ginger extract and vitamin C. The process was evaluated using a central composite design and analyzed using the response surface methodology. The independent variables were considered: fluidization air inlet temperature (50–70 °C), process time (30–50 min), and atomization pressure of binder solution (1–2 bar). The experimental optimization of multiple responses (desirability 74%) defined the independent variables as fluidization air inlet temperature 70 °C, process time 43.7 min, and atomization pressure of binder solution 1.3 bar. The dependent variables were: moisture (4.7 ± 0.1%), solubility (80.2 ± 2.2%), hygroscopicity (20.3 ± 1.8%), wettability (17.8 ± 0.6 s), Carr Index (10.7 ± 1.9%), Hausner ratio (1.12 ± 0.02), total polyphenols (310.1 ± 4.3 mg GAE/100gdb), total flavonoids (202.9 ± 7,2 mg QE/100gdb), ABTS (198.8 ± 12.1 mg TE/100gdb), DPPH (239.25 ± 9,0 mg TE/100gdb), vitamin C (179.2 ± 4.3 mg AA/100gdb) and β-carotene (544.4 ± 8.9 μg/100gdb). The agglomerated pineapple powder mixture presented better flow and instantaneous properties than the pineapple powder mixture obtained by spray drying. In addition, the product retains levels of active components that guarantee an important source of antioxidants.

Impact of the agglomeration process on the flow, reconstitution, and antioxidant properties of an Andean berry powder mix

BACKGROUND: There is consumer interest in berries due to their nutritional properties, especially biologically active compounds. Spray drying technologies improve products stability and shelf life, and the agglomeration process subsequently enhances powder instantaneousness and flow properties. OBJECTIVE: The aim was to evaluate the effect of the fluidized bed agglomeration process on flow, reconstitution, and antioxidant properties of cape gooseberry, strawberry, and blackberry powder mix obtained by spray drying and a water and vitamin C binding solution. METHODS: A face-centered central composite design with 15 experiments was used; independent variables were fluidization temperature (T), binder solution atomization pressure (P), and process time (t), while dependent variables were moisture, solubility, wettability, particle size, antioxidant capacity, total phenols, Vit. C, β-carotenes (β-car), and total anthocyanins. RESULTS: The best process conditions from experimental optimization were T = 70 °C, P = 1.1 bar, and t = 29.1 min. This agglomerated product had low moisture values, good solubility, and 0.5 min wettability; the values for Vit. C = 246.4±3.4 mg/100 g db, β-car = 4.0±0.5 mg/100 g db, and total anthocyanins = 230.7±3.0 mg C3G/100 g db were noteworthy. CONCLUSIONS: An agglomerate berry-based powder product was obtained with 100% Vit. C RDA (Recommended Dietary Allowances) and 15% vitamin A RDA. Flow and instantaneousness properties of the agglomerated powder also significantly improved with the applied process.

Improvements in the Physical Properties of Agglomerated Milk Protein Isolate/Skim Milk Powder Mixtures Via Fluidized Bed Agglomeration

Protein-enriched dairy powder is widely consumed to promote muscle synthesis. Recently, in Korea, elderly people have also begun consuming protein powder products to prevent muscle loss. However, these protein-enriched powders have poor flowability and hydration properties because of the fine particles of spray-dried milk protein powder. Therefore, in this study, the fluidized bed agglomeration process was used to solve these problems. The rheological and physical properties of milk protein isolate (MPI)/skim milk powder (SMP) mixtures were effectively improved via fluidized bed agglomeration. The particle size of the MPI/SMP mixtures significantly increased from 35.7–58 μm to 118–136 μm, the flowability level improved from fair (21.4–26.3) to good (15.7–16.3), and the cohesiveness level changed from intermediate (1.27–1.36) to low (1.18–1.19) after fluidized bed agglomeration. In addition, the wetting time of the agglomerated MPI/SMP mixtures was effectively reduced to 4.67–58.3 s by fluidized bed agglomeration. These findings may be useful for manufacturing protein-enriched dairy powders with good instant properties.

Early Detection of Agglomeration in Fluidized Beds by Means of Frequency Analysis of Pressure Fluctuations

For description of the fluidization state of fluidized beds, both time-domain and frequency-domain analyses of high-frequency pressure fluctuations are established approaches. Common methods for the detection of agglomeration or defluidization in fluidized beds use the variance or the standard deviation of the pressure signal or the maximum in its frequency spectrum. These methods are used, for example, in biomass combustion or gasification. However, these approaches lack the reliability for applications as an early agglomeration warning system in industrial applications. To address this issue, the present study introduces a robust methodology by means of extracting a characteristic frequency from the power spectral density of the pressure signal. A comparison of our developed approach with the commonly used frequency maximum and standard deviation for predicting the onset of agglomeration in laboratory experiments shows promising sensitivity on agglomeration formation. In order to evaluate the general applicability of this method on an industrial scale, this work investigates dependencies of possible influences, such as gas velocity, sand quantity, and temperature, on the characteristic frequency. The results indicate that the characteristic frequency can be a promising and robust method for the early detection of the onset of agglomeration in industrial plants.