Particle Moisture Content Research Articles

Prediction model of moisture content in spray drying of ceramic slurry based on IMFO-BPNN

The final particle moisture content of ceramic slurry spray drying affects the processing, product quality, and process energy consumption. While the real-time moisture content determination is very difficult for spray drying process due to nonlinear, severe lag, interference factors, and complexity of the systems, the high temperature, high humidity drying environment and short drying process. In current work, an improved moth optimization (IMFO) algorithm combined with backpropagation neural network (BPNN) was proposed to predict the moisture content of ceramic slurry particles during spray drying. The performance of the model is trained and tested. Results demonstrate that IMFO has better convergence ability and speed compared to other algorithms such as particle swarm optimization (PSO) and gravitational search algorithm (GSA). The IMFO-BPNN model achieves a MAE of 0.0293, RMSE of 0.0383, and R2 value of 0.9113, outperforming the prediction performance of BPNN and MFO-BPNN models. The absolute error rate of the IMFO-BPNN model (0–5%) is lower compared to BPNN (5–10%) and MFO-BPNN model (>10%), showcasing superior accuracy in predicting moisture content. This mathematical model established in the study provides an efficient, accurate, and nondestructive method for predicting the drying endpoint of ceramic slurry spray drying.

A non-contact solid particle moisture sensor based on near-infrared spectroscopy technology

The detection of moisture content in solid particles has important applications in fields such as biological research, coal mine production, and medicine. This article develops a non-contact solid particle moisture sensor (NcSPMS). NcSPMS uses the multi-light source detection method based on the principle of diffuse reflection absorption to detect the moisture content of solid particles with different particle sizes, distributions and colors. Firstly, the stacked LED light source structure (SLED-LSS) was designed to achieve illumination of LED light source for measurement (M-LED) and the LED light source for reference (R-LED) at the same position and exit angle, eliminating the influence of irregular particle size and distribution on diffuse reflected light intensity. Secondly, the stacked LED array light source structure (SLEDA-LSS) was designed to improve the detection light intensity and enable NcSPMS to detect the moisture content of solid particles of different colors. Thirdly, modulated light technology is used for the transmission of moisture content information. Two modulation frequencies were set to modulate the measurement light source and reference light source, and different intensities of square wave currents were determined to drive the M-LED and R-LED to improve detection accuracy. Fourthly, the FFT-KF data processing method was designed to effectively extract the information of diffuse reflection measurement light intensity. Finally, the function expression of moisture content was obtained through cubic fitting, and the detection of moisture content by NcSPMS was achieved. In order to verify the effectiveness of NcSPMS, the NcSPMS control system was designed. The experimental results show that compared with SLED-LSS, SLEDA-LSS improves measurement accuracy; the different current pairs driving M-LED and R-LED affect the measurement accuracy of NcSPMS; NcSPMS can detect the moisture content of white, yellow, green, red, and black sand particles, with the detection range of 0.10–11.00 %. The relative uncertainty obtained by applying NcSPMS to the detection of nickel ore particles is 4.37 %.

Enzyme-induced Carbonate Precipitation (EICP) Combined with Lignin to Improve the Unconfined Compression Strength (USC) of Shanghai Clay

In order to improve the mechanical properties of high moisture content and low strength of clay particles in Shanghai, the effects of different lignin content on the unconfined compressive strength of EICP-lignin-cured clay were studied by using the method of lignin combined with EICP technology to strengthen the clay by lignin combined with EICP technology. The experimental results showed that EICP-lignin could enhance the unconfined compressive strength of Shanghai clay. With the increase of lignin content, the unconfined compressive strength of clay first increased and then decreased, and there was an optimal content value. The optimal lignin content is 8%.

Modeling of multiphase heat and mass transport and drying behavior of potash particles in a packed bed: Experiments and simulation

The drying behavior of potash particles was experimentally investigated in a convective packed bed dryer under different operating conditions, including inlet gas temperature of 40 °C, 50 °C, and 60 °C, moisture content of 2.8 wt%, and superficial gas velocity of 0.3 m/s. When the temperature increased from 40 °C to 50 °C and then to 60 °C, the drying time decreased from 930 s to 870 s and then to 720 s, respectively. The thermal conductivity and specific heat capacity of potash particles as a function of moisture content and porosity of the packed bed was determined at a 95 % confidence interval to have R2 values of 0.94 and 0.91, respectively. During drying of potash particles, solid bridges form, and the whole bed behaves like a porous medium with void spaces that expand. In this work, a conjugate heat and mass transfer model was developed for batch packed bed drying of wet potash particles. Computational fluid dynamics was used to simulate the momentum, mass, and energy transport in a porous medium based on the physical properties of potash particles. The model successfully correlated the experimental particle moisture content versus time with average absolute deviation percentage values of 14.8, 3.2, and 14.7 for the inlet gas temperatures of 40 °C, 50 °C, and 60 °C, respectively.

Kinetics of simultaneous recovering of Au and Ag from CTs by chloridizing volatilization methods

Cyanide tailings (CTs), which amount to hundreds of millions of tons and pose significant a danger to the environment's ecology, are regarded as hazardous waste. This study suggests an efficient and environmentally favorable method for the recovery of gold and silver from CTs. The influence of calcium chloride dosage, silicon dioxide dosage, pellet moisture content, roasting temperature, and roasting duration on chloridizing volatilization of Au and Ag was investigated. The simultaneous recovery of gold and silver from cyanide tailings via heating with chlorination was also investigated. It was found that the calcium chloride dosage and temperature increase the chloridizing volatilization rates, while the silicon dioxide dosage and particle moisture content decrease it. The inter-diffusion through the gangue layer served as the rate-limiting phase in the chloridizing volatilization kinetics, which was based on the shrinking core model. The apparent activation energies (Ea) of 24.01 kJ•mol-1 (Au) and 24.62 kJ•mol-1 (Ag) are in agreement with this result. The orders of reaction corresponding to various values of temperature, moisture content, silicon dioxide, and calcium chloride dosages were also computed. Semi-empirical equations can be used to describe the rate of reaction in diffusion-controlled processes.

Harnessing the Thermal Potentials of Bitter Kola Tree Using Thermo- Gravimetric Analysis (TGA) Method

This research focused on harnessing the thermal potentials of the bitter kola tree relying on the information determined by the Thermo-gravimetric Analyzer. Today the world is facing some critical problems such as: high fuel prices, climatic changes, and air pollution. Higher Heating Value (HHV) is one of the most important properties of fuels which explains the higher energy content and determines the efficient use of biomass and fossil fuels. This research work aimed to conduct thermo-gravimetric analysis on Bitter kola tree energy crop. The materials for the research was acquired from a nearby farmland and further dried under sunlight for a period of four weeks before being dried further in the oven at regulated constant temperature, it was pulverized and further analyzed to determine the moisture content, ash content, crude fat, crude protein and crude fibre. From the experimental results, it was revealed that the moisture content of bitter kola tree particles was very high (44.37) compared to mangrove (22.75). The volatile matter was very low (43.47) compared to mangrove (55.65). These facts are responsible for the low combustion characteristics of bitter kola tree. This project work will educates anyone who chooses to venture into biomass generation of energy with energy crops to know the exact crop sample with the highest heating value for increased coefficient of performance and efficiency of the steam or turbine engines to be used for generating electricity.

Modeling the inactivation kinetics of lactic acid bacteria in a spray dryer

Changes in the viability of probiotic cells during spray drying were tracked, by developing an inactivation model of Lactobacillus rhamnosus GG (LGG) and coupling the model to the drying kinetics of spray drying using Computational Fluid Dynamics simulation. Six inactivation models in the Arrhenius-equation form were developed using single droplet drying experiments with average drying rates of 0.011–0.044 kg/kg/s; all gave reliable goodness-of-fit. In simulating spray drying process, the predicted moisture content of LGG-containing particles well followed experimental trends. However, only inactivation model 6, which incorporated droplet temperature, moisture content, rate of temperature change, and drying rate, accurately predicted the survival of LGG. Models 1–5 that incorporated fewer kinetics parameters with higher activation energy values underestimated the degree of inactivation. The findings highlighted the crucial effects of the rates of temperature and moisture content change on the inactivation of probiotics during rapid drying with average drying rates of 0.31–0.81 kg/kg/s.

Investigation of wetting and drying process in a spout-fluid bed using acoustic sensor and electrical capacitance tomography

To investigate complex gas-solids flow characteristics of a spout-fluid bed with bafflers in wetting and drying process, a non-intrusive measurement technique combining pressure, acoustic transmitters and an electrical capacitance tomography (ECT) sensor is proposed in this paper. The proposed approach can collect acoustic and pressure signals and realize visualization in three flow regions separated by two bafflers synchronously. By ECT images and power spectrum and wavelet analysis of the pressure drop signals, two typical flow state transitions in the wetting and drying process can be identified. The result analysis based on acoustic transmitter indicates that the particle–wall collision frequency band is narrow and the particle–particle collision frequency band is wide. A key recurrence quantization parameter of acoustic signal, Laminarity, increases with the decrease of particle flowability. The parameter of Laminarity combined with the capacitance signal related to the particle moisture content can effectively reflect the wetting rate and provide an accurate monitoring of de-fluidization process in the bed.

Моделирование процесса cушки вторичного сырья в технологической линии производства активированного угля

Mathematical modeling of the convective drying process for the activated carbon production line, which is an effective and inexpensive adsorbent, is presented. At the Department of Wood Materials Processing of Kazan National Research Technological University (KNITU), a pyrogenetic processing unit for secondary raw materials into activated carbon was developed. An important stage in the preparation of raw materials for thermal processing is its drying, which reduces the energy costs of heating the material. To identify the optimal technological parameters of the convective drying process, numerical mathematical modeling of changes in the moisture content and temperature of wood particles was carried out by solving a system of heat and mass transfer equations recorded for an infinite plate. Dynamic curves of temperature and humidity of the material have been obtained, which will allow us to recommend technological parameters for the installation. The approbation of the mathematical.

Moisture content characterization method of wet particles of brown rice based on discrete element simulation

The moisture content of brown rice wet particles was characterized based on discrete element simulation. Firstly, the angle of repose under different moisture content was determined by physical experiment, and the regression equation of moisture content and angle of repose was established, R2 = 0.9718. Then, the mathematical model between the angle of repose and the key discrete element parameters was established by discrete element simulation experiments, R2 = 0.9938. Finally, a mathematical model between moisture content and key discrete element parameters was established, and the maximum relative error of simulated angle of repose and physical angle of repose was verified to be 3.09%. The results show that the constructed wet grain discrete element parameter model of brown rice can be used for simulation research, which has guiding significance for the design of brown rice processing device.

CFD Simulation and Experimental Study on a Thermal Energy Storage–Updraft Solid Waste Gasification Device

A thermal energy storage–updraft gasification device is a type of reactor that should be considered for use in solid waste gasification research that can save energy. However, the operating parameters and internal flow field during its operation remain unclear. In this study, a numerical model of the thermal energy storage–solid waste gasification device based on the computational fluid dynamics dense discrete phase model (CFD-DDPM) which had almost never been used before was established, and an innovative method that causes particles to be piled to simulate the gasification process was proposed according to the updraft fixed bed gasification characteristics; meanwhile, solid waste gasification experiments were conducted on the device. This study focused on the influence of moisture content and excess air coefficient on the gasification process of solid waste particles, and the velocity, pressure, temperature, and species distribution of the internal flow field of the device were analyzed. Simulation results showed that the higher the moisture content of particles, the greater the amplitude of changes in the internal physical field of the device. The fluid pressure drop is around 25 Pa–75 Pa for different working conditions. The combustible species of the gas of moist particles raise slightly with the increase in excess air coefficient, while the dry particles have the opposite effect. Compared with other gasification devices of the same type, the hydrogen production of this device is about 2–3 times higher. Our findings could facilitate the analysis, predict the operation status, and provide a theoretical basis for the improvement of this device.

Microencapsulated propolis in chewing gum production

Propolis is a resin with high antibacterial and antioxidant properties that honey bees (Apis mellifera L.) gather and then harmonize through their metabolic secretions. Propolis is beneficial to dental health because it contains antibacterial activity against the Streptococcus mutans, which causes tooth decay. The aim of this study is to use microencapculated propolis extract (MPE) in chewing gum formulation for the first time, in order to protect propolis from environmental effects during production and to ensure controlled release in mouth. Spray drying method was applied where maltodextrin acted as coating material. The particle structure of MPE was investigated by scanning electron microscope. The encapsulation efficiency was determined as 62.19%. The hygroscopicity and moisture content of the MPE particles was found as 31.50% and 7.98% respectively. The DPPH scavenging ability, total flavonoid and total phenolic content of the MPE appeared lower than propolis extract. The total flavonoid content of MPE was calculated as 29.06 mg/kg and total phenolic content as 89.17 mg/kg. In vitro antimicrobial activity against Streptococcus mutans of 9% MPE containing gum samples was measured highest with 4.20 mm zone diameter. Hunter b* value increased with increasing MPE concentration. The final MPE incorporated chewing gum appear to be highly functional.
 Keywords: Propolis; Spray drying; Chewing gum; Functional food

Effects of moisture on soot generation and ignition of coal particle: Investigation and evaluation with OH-planar laser induced fluorescence

Coal with a high moisture content is increasingly being utilized in power generation. However, the influence of moisture on coal ignition and soot generation characteristics remains unclear. Understanding the effect of moisture on coal ignition and soot generation characteristics is important for improving energy efficiency in coal utilization. The characteristics of soot generation and ignition of lignite coal including different contents of moisture (0%, 5%, 10%, 15%) were studied with Planar Laser Induced Fluorescence of OH radicals (OH-PLIF) on a novel concentrating photothermal platform. The results showed that the ignition delay time (tign) of coal and observed soot generation during volatile combustion by the observation of flame luminosity both increased as the moisture content of the coal particles increased from 0% to 15%. The observed increase in tign corresponded to the decreased OH intensity during the ignition. Similarly, the increased generation of soot during volatile combustion corresponded to the increased OH intensity resulting from increased moisture content in the coal. Before ignition, the steam surrounding the coal particle inhibits the release of volatiles. Thus, the formation of fuel molecules (RH) is reduced. Simultaneously, the inhibitory effect of moisture on RH leads to a decrease in H atoms, which further results in a decline in OH radical concentration resulting from the reaction H + O2→OH + O. The combined effect of reduced RH and OH concentrations inhibits ignition for coals containing moisture. During volatile combustion, although OH is commonly acknowledged as the primary oxidant for soot, the increase in OH facilitates gasification reactions, thereby promoting the massive release of volatiles. These volatiles, through processes such as nucleation reactions, contribute to the formation of an increased amount of soot, consequently resulting in an elevated formation of soot in coal with higher moisture content.

Unanswered questions on the airborne transmission of COVID-19.

The online version contains supplementary material available at 10.1007/s10311-022-01557-z.

Prediction of principal stresses due to external load in sans mass considering its mechanical characteristics

Introduction. A part of the methods for designing earthworks and foundations is based on solutions for predicting the stress state of soils under the action of an external load, which do not take into account the structural features of the material. This is in conflict with current studies, which indicate that changes in the moisture content, density, and shape of material particles entail changes in the mechanism of stress state formation. According to some research, when the type of soil, moisture content and density of the mass change, both its mechanical characteristics and the stress state change, which requires consideration in the design of earthworks and building foundations.The method of research. To study the stress state arising in sandy soil with different mechanical characteristics, experimental studies were carried out to determine the pressures in sand of different density and moisture under the action of an external load from a round stamp with an area of 500 cm2. To do this, at a depth of 5, 15, 25, 40 cm along the axis of a round stamp in an array of sand of medium size, mesdoses were set, after which the pressures were measured when the load was applied. For each value of density and moisture created during the experiment, the mechanical characteristics of the sandy soil were determined.Results. The analysis of the existing dependencies for predicting the maximum principal stresses showed that the Kandaurov and Frohlich’s solutions are the only ones that give a connection between the formation of the stress state and mechanical characteristics and allow predicting the minimum principal stresses. The influence of the mechanical characteristics of sandy soil (the angle of internal friction and the modulus of elasticity at different density and humidity) on the Frohlich’s parameter and the distribution capacity coefficient of the medium of the Kandaurov’s solution was established.Conclusion. The analysis of the results of experimental studies made it possible to derive dependencies for predicting the maximum principal stresses of sandy soil at points located at different depths along the axis of a loaded round stamp. The proposed dependencies are a modification of Kandaurov and Frohlich’s solutions, which take into account the relationship between the mechanical characteristics of sandy soil and the parameters of the distribution capacity of the medium.

Sifat Fisika dan Mekanika Papan Partikel Berbahan Limbah Industri PT. Aldi Mandomai Mebel

This research aims to determine the effect of particle sizes (10 mesh, 20 mesh, and 30 mesh) on the physical and mechanical properties of particleboards made from industry waste of PT. Aldi Mandomai Furniture, based on JIS A 5903: 2003 Standard. . Particleboards size were 30 x30x1,5 cm, density 0,5 g/cm3. Moisture content particles at 5%, particles glued with urea-formaldehyde adhesives, weight 10%, hot press pressured with temperature 110 ± 20C for 15 minutes, pressure 25 kg/ cm2. Furthermore, particleboards must be conditioned for ± 14 days/ 2 weeks. Particleboards were cut into sample test according to the size in the JIS A 5903:2003 standard. Research design used Completely Random Design with one factor. Data analyzed using analysis of variance, if data was significant must to do areal difference test. The observed to particle size with 3 levels are 10 mesh, 20 mesh, and 30 mesh. The results of physical properties were Density ( a.v. 0,46 – 0,49 g/cm³), Moisture Content (a.v. 12,22 – 14,05%), Water Absorption (a.v 129,79 – 167,03%), and Thickness Swelling (a.v 11,43 – 22,08%). The results of mechanical properties were internal bonding (0,0075 - 0,0204 N/mm2), Modulus of Elasticity (a.v. 5,91 – 25,32 N/mm2), Modulus of Rupture (a.v 0,52 – 1,52 N/mm2 ), and Screw Holding (a.v. 29,42 – 104,60 N). Particleboards made from furniture industry waste with particle size 10 mesh was significantly to physical properties, except density and fulfill JIS A 5903:2003, while the mechanical properties of particleboard are not fulfill the standard.

Modeling resilient modulus of subgrade soils using LSSVM optimized with swarm intelligence algorithms

Resilient modulus (Mr) of subgrade soils is one of the crucial inputs in pavement structural design methods. However, the spatial variability of soil properties and the nature of test protocols, the laboratory determination of Mr has become inexpedient. This paper aims to design an accurate soft computing technique for the prediction of Mr of subgrade soils using the hybrid least square support vector machine (LSSVM) approaches. Six swarm intelligence algorithms, namely particle swarm optimization (PSO), grey wolf optimizer (GWO), symbiotic organisms search (SOS), salp swarm algorithm (SSA), slime mould algorithm (SMA), and Harris hawks optimization (HHO) have been applied and compared to optimize the LSSVM parameters. For this purpose, a literature dataset (891 datasets) of different types of soils has been used to design and evaluate the proposed models. The input variables in all of the proposed models included confining stress, deviator stress, unconfined compressive strength, degree of soil saturation, soil moisture content, optimum moisture content, plasticity index, liquid limit, and percent of soil particles (P #200). The accuracy of the proposed models was assessed by comparing the predicted with the observed of Mr values with respect to different statistical analyses, i.e., root means square error (RMSE) and determination coefficient (R2). For modeling the Mr of subgrade soils, percent passing No. 200 sieve, optimum moisture content, and unconfined compressive strength were found to be the most significant variables. It is observed that the performance of LSSVM-GWO, LSSVM-SOS, and LSSVM-SSA outperforms other models in predicting accurate values of Mr. The (RMSE and R2) of the LSSVM-GWO, LSSVM-SSA, and LSSVM-SOS are (6.79 MPa and 0.940), (6.78 MPa and 0.940), and (6.72 MPa and 0.942), respectively, and hence, LSSVM-SOS can be used for high estimating accuracy of Mr of subgrade soils.

Influence of Relative Humidity on the Characteristics of Filter Cake Using Particle Flow Code Simulation

To study the effect of air humidity on particle filtration performance, the Particle Flow Code (PFC) calculation program was used to numerically simulate the formation process of filter cake. The effects of relative air humidity on the deposition morphology, porosity and filtration resistance characteristics of the filter cake were revealed. The results show that relative humidity (RH) is mainly reflected in the density and surface viscosity of the particles. It was found that the higher the relative humidity, the higher the particle moisture content, the greater the density, and the greater the surface viscosity. With an increase in the particle density or with a decrease in the viscosity, the bridging phenomenon of particle deposition became more obvious; the dendritic deposition phenomenon became weaker; and, therefore, the filter cake structure became denser; the porosity decreased; and the total filtration resistance increased. As the humidity changed, the actual density and viscosity of the particles changed simultaneously with different degrees, which caused different variation trends of the filter cake characteristics. Three different types of particles, DM828 (Starch), PVA1788 (Polyvinyl Alcohol) and Polyacrylamide (Polyacrylic acid), were selected for comparison. For the studied PVA1788 and Polyacrylamide particles, with an increase in relative humidity, the porosity of the filter cake increased monotonously, while the total filtration resistance decreased monotonously. For DM828 particles, the cake porosity first decreased and then increased, and the total filtration resistance first increased and then decreased, with an inflection point at 30% RH. By combining these results with existing reports, three kinds of variations of the filtration performance with humidity could be determined: (1) as the humidity increased, the filtration resistance first increased and then decreased; (2) the filtration resistance decreased; and (3) the filtration resistance increased.

Production and evaluation of particleboards made of coconut fibers, pine, and eucalyptus using bicomponent polyurethane-castor oil resin

This research examined the influence of the compositions between coconut fiber (Cocos nucifera) and wood particles (Pinus taeda L. and Eucalyptus saligna) on physico-mechanical properties of homogeneous particleboards. The exploratory study was carried out under Tukey’s contrast test of means, at 5% significance level, with the following compositions: 100% coconut fiber (F100 P0 E0); 50% coconut fiber, 25% pine particles, and 25% eucalyptus particles (F50 P25 E25); and 50% of pine particles and 50% of eucalyptus particles (F0 P50 E50), with particle moisture content between 0% to 2% and 10%, in mass, of polyurethane-castor oil (PU-Castor) resin. Three panels were produced for each composition. The physico-mechanical properties such as density, moisture content, swelling in thickness after 24 h of immersion in water, perpendicular tensile strength, static bending strength, and modulus of elasticity were evaluated using standard methods. The results obtained indicated the potential for using coconut fiber for the production of homogeneous particleboards in view of the minimum criteria required by the normative documents, with emphasis on the physical property of swelling after 24 hours, which obtained a statistically equivalent average relative to the treatment that contained only wood particles.

CFD–DEM simulation of wet granular-fluid flows and heat transfer in an integral multi-jet spout-fluidized bed

The hydrodynamic and heat transfer characteristics of dry and wet particles in quasi-two-dimensional integral multi-jet spout-fluidized bed (IMJSFB) and conventional spouted bed (CSB) were numerically studied using Computational Fluid Dynamics-Discrete Element Method (CFD-DEM), where the effect of wet content of particles is realized by introducing the liquid bridge force. In addition, the agglomeration, particle mixing, circulation, collision and heat transfer of IMJSFB and CSB under different moisture content were quantitatively studied. It is found that with the increase of gas velocity, the circulation capacity of particles in both spouted beds increases first and then decreases, and particle circulation characteristics of IMJSFB are obviously better than those of CSB. The appropriate moisture content of particles is beneficial to enhance the heat transfer effect, and compared with CSB, IMJSSFB has more obvious advantages in dealing with wet particles. This study has important significance for the mixing and heat transfer of class D wet particles, which is less studied in fluidization technology, and provides theoretical and technical reference for the actual design and operation of spouted bed.