Pellet Parameters Research Articles

Data Acquisition and Diagnostic System for Prototype of PANDA Pellet Target

In the PANDA experiment of the FAIR project, it is proposed to use internal targets based on the hydrogen isotopes that provide a monodisperse regime of flow generation of solid spherical pellets with the diameter from 15–40 µm with the frequency from several tens of to several hundred kilohertz. The process for generating the pellets in such facilities includes the cooling, liquefying, and disintegration into drops of the liquid hydrogen jet directed vertically downwards; freezing of the jet when expiring with acceleration into vacuum; and its transport through the vacuum path into the region of interaction with the antiproton beam. For the effective control of the systems of the setup and for the adjustment of generation of pellets, an automatization and control system is developed combining the devices for measurement and control of pellet parameters (temperature, pressure, hydrogen flow, and piezoelectric generator frequency) and the optical diagnostics in a unified computational network. For data exchange between the devices, the TCP/IP Sockets and Modbus TCP protocols are used.

Methodology for quickly determining the quality of pellets

A methodology for quickly and easy determination the quality of pellets offered on the market is developed on the basis of "theory of graphs". The pellet quality assessment is performed in two ways - by direct control (non-destructive measurements) and by combustion. The following pellets parameters are determined at the direct control stage: friability, homogeneity, presence of dark stains and moisture content. The experimental measurement of following parameters of the combustion process is carried out at the stage of pellet burning assessment under real conditions: temperature in the combustion chamber, time for complete combustion of the pellets and the amount of ash after pellets combustion. The calorific value of the tested pellets is determined on the basis of the experimentally obtained parameters of the combustion process. The the obtained parameters values are statistically processed according to the described in the paper equations at the next stage. Then the results for the investigated pellet parameters are compared with the normative values. The proposed methodology could be calibrated by experimental determining the calorific value of investigated pellets by a calorimeter. Practical application of this methodology is that by not so complicated measurements and calculations the required amount of pellets for heating a building with a certain energy consumption for heating season could be determined.

Study of the Influence of the Intrinsic Parameters of Charcoal Pellets and Relative Humidity on Compressive Strength and Moisture Adsorption

In this study, charcoal fines mixed with wheat starch or arabic gum were used to produce pellets. Moisture adsorption increased greatly by increasing relative humidity. Moisture adsorption depends also on the binder type used. All charcoal pellets had compressive strength above 1.0 MPa and their moisture adsorption reached 3% to 12% depending on relative humidity conditions. In authors' experiment field, statistical analysis showed that binder type and the rate of binder had more significant effects on compressive strength. The moisture adsorption was more influenced by relative humidity and binder type.

Three dimensional thermal conduction of randomly packed beds of porous cylindrical ceria pellets immersed in carbon dioxide with effects of deviations of pellet porosities and sizes

Structures of randomly packed beds of cylindrical shape porous pellets composed of tiny ceria (CeO2) particles with wide ranges of pellet porosities and number density probabilities are generated by an improved controllable structure generation scheme (CSGS) including deviations of both pellet porosities and sizes. Three dimensional (3D) mesoscopic scale thermal conduction through the structures immersed in carbon dioxide (CO2) gas is simulated by a parallel non-dimensional lattice Boltzmann method (P-NDLBM). Effective thermal conductivity (ETC) in each direction and 3D temperature distributions with effects of pellet number density probabilities, porosities, and deviations are illustrated. Although the pellet number density probability and pellet porosity are equivalently important for changing of macroscopic global porosity, they have different effects on temperature distribution patterns and the overall ETC. A new form of ETC correlation related to the pellet number density probability and pellet porosity is proposed. The present ETC correlation based on the two pellet parameters shows a slight improvement comparing to conventional forms based on the macroscopic global porosity.

Application of Aluminum Oxide Nanoparticles in Aspergillus terreus Cultivations: Evaluating the Effects on Lovastatin Production and Fungal Morphology.

Aluminum oxide nanoparticles were supplemented to Aspergillus terreus ATCC 20542 precultures and the outcomes of the process were evaluated relative to the results of microparticle-enhanced and standard cultivations. The selected morphological parameters of fungal pellets (projected area, elongation, convexity, and shape factor) were monitored throughout the experiment, together with biomass, lactose, and lovastatin concentration. The qualitative and quantitative chemical analysis was performed with the use of liquid chromatography coupled with high resolution mass spectrometry. The results of the study indicated that the application of nanoparticles was indeed associated with morphological consequences, most notably the decreased pellet size. However, it turned out that the term “nanoparticle-enhanced cultivation” could not be used in the context of lovastatin production, as no marked increase of product titer was observed in nanoparticle-influenced variants relative to standard and microparticle-enhanced cultivation. In addition, the concentration of biomass in the nanoparticle-influenced runs was relatively low. Comparative analysis of total ion chromatograms revealed the presence of a molecule of unknown structure that could be detected solely in broths from standard and microparticle-containing cultures. This study represents the first evaluation of nanoparticles as the tools of morphological engineering aimed at enhanced lovastatin biosynthesis in A. terreus cultures.

Design and test bench operation results of a solid hydrogen pellet injector developed for SST-1 tokamak

A single barrel pellet injection system is developed for pellet injection related studies targeting SST-1 tokamak plasma. Conventional pipe gun concept is adopted for designing the injector. The hydrogen ice is formed in-situ in the gun barrel, and a high pressure light propellant gas is used to dislocate the pellet from the freezing zone and accelerate it to higher speed. This system uses a cryogen free, closed loop compact cryocooler, which provides ease of handling and operational reliability to the pellet freezing process. Pellet parameters such as size and speed are considered by using the density limit and neutral gas shielding (NGS) model based calculations, respectively. The designed size and speed (Vp) of the pellet is fixed at (1.6 mm length [ℓ] × 1.8 mm diameter [φ]) and Vp < 800 m/s, respectively. A programmable logic controller (PLC) based control system and a graphical user interface (GUI) is developed and installed to operate the injector remotely. This paper presents the design and test results of the injector such as pellet freezing capability, effect of temperature gradient along the barrel on pellet formation process and its speed control with propellant pressure.

Final design of the JT-60SA pellet launching system for simultaneous density and ELM control

The key mission of the new tokamak JT-60SA is to conduct exploitations in view of ITER and to resolve key physics and engineering issues for DEMO. Its pellet launching system was designed to cover according requirements by providing a powerful and flexible tool for the control of density profile and ELM frequency. Modelling showed inboard launch is mandatory in order to achieve high fuelling efficiency, by analysing the potential pellet fuelling impact in all relevant plasma scenarios the optimized set of pellet parameters for fulfilling all the tasks requirements was elaborated. Accordingly, the systems layout had to be adapted for pellet injection via a guiding tube from the vessel inboard side. Currently, efforts are under way in order to elaborate the most appropriate solution yielding minimised pellet transfer losses and a maximum transfer speed yet compatible with boundary conditions imposed by the vessel already under construction. The feasibility of a mechanical centrifuge as pellet acceleration unit was studied. This approach would guarantee the precise pellet launch speed as needed to enable the best adaptation to the guiding tube transfer capabilities and accurate control of pellet frequency and particle flux as arriving in the plasma. While the appropriateness of the centrifuge principle has been already proven by several devices, the proposed version possesses a novel design employing several accelerator arms. Such, operation at heighten rates and with a more refined adjustment of pellet flux and frequency could be achieved. Moreover, it allows hosting several sources delivering different pellets and their simultaneous actuation. The appropriate control unit is designed to merge pellets from different sources to form a sequence for the simultaneous control of different basic plasma parameters as e.g. density and ELM frequency. This flexibility can also allow including additional applications, like isotope fraction control or radiative power exhaust by using compound pellets. At present, the detailed engineering of all major components is in progress, finally aiming to provide specifications and get ready to prepare the procurement process.

Multiple response optimisation of processing and formulation parameters of pH sensitive sustained release pellets of capecitabine for targeting colon

Purpose: To optimise the Eudragit/Surelease®-coated pH-sensitive pellets for controlled and target drug delivery to the colon tissue and to avoid frequent high dosing and associated side effects which restrict its use in the colorectal-cancer therapy.Methods: The pellets were prepared using extrusion-spheronisation technique. Box–Behnken and 32 full factorial designs were applied to optimise the process parameters [extruder sieve size, spheroniser-speed, and spheroniser-time] and the coating levels [%w/v of Eudragit S100/Eudragit-L100 and Surelease®], respectively, to achieve the smooth optimised size pellets with sustained drug delivery without prior drug release in upper gastrointestinal tract (GIT).Results: The design proposed the optimised batch by selecting independent variables at; extruder sieve size (X1 = 1 mm), spheroniser speed (X2 = 900 revolutions per minute, rpm), and spheroniser time (X3 = 15 min) to achieve pellet size of 0.96 mm, aspect ratio of 0.98, and roundness 97.42%. The 16%w/v coating strength of Surelease® and 13%w/v coating strength of Eudragit showed pH-dependent sustained release up to 22.35 h (t99%). The organ distribution study showed the absence of the drug in the upper part of GIT tissue and the presence of high level of capecitabine in the caecum and colon tissue. Thus, the presence of Eudragit coat prevent the release of drug in stomach and the inner Surelease® coat showed sustained drug release in the colon tissue.Conclusion: The study demonstrates the potential of optimised Eudragit/Surelease®-coated capecitabine-pellets for effective colon-targeted delivery system to avoid frequent high dosing and associated systemic side effects of drug.

Structural concrete using expanded clay aggregate: a review

Objectives: The research in relation to the use of Expansive Clay Aggregate (ECA) to produce structural light weight concrete is summarized in this paper. Methods/Analysis: The manuscript discussed about the constituent parameters of the aggregate such as physical and chemical properties of clay aggregate, the pelletization parameters such as angle of inclination, rotation speed, and duration of pelletization process and its influence on the aggregate properties. The physical and mechanical properties of the ECA were also briefed. Findings: The review of literatures show that the specific gravity of these aggregate was 16–46% less than that of the normal weight aggregates and possess higher water absorption. The fresh and mechanical properties of the concrete produced with Expansive clay Aggregate concrete were also summarized. Expansive Clay aggregate concretes have the 28-day compressive strengths in the range of 23–60 MPa, with densities in the range of 1290–2044 kg/m3. The durability properties of the Expansive Clay aggregate concretes indicate that the performance is satisfactory for structural applications. Novelty/Improvement: The review indicates that Expansive clay aggregate is one of the potential materials for the development of structural concrete. Keywords: Durability, Expansive Clay Aggregate, Light Weight Concrete, Structural Concrete

Modeling the UO2 ex-AUC pellet process and predicting the fuel rod temperature distribution under steady-state operating condition

Modeling uranium dioxide pellet process from ammonium uranyl carbonate - derived uranium dioxide powder (UO2 ex-AUC powder) and predicting fuel rod temperature distribution were reported in the paper. Response surface methodology (RSM) and FRAPCON-4.0 code were used to model the process and to predict the fuel rod temperature under steady-state operating condition. Fuel rod design of AP-1000 designed by Westinghouse Electric Corporation, in these the pellet fabrication parameters are from the study, were input data for the code. The predictive data were suggested the relationship between the fabrication parameters of UO2 pellets and their temperature image in nuclear reactor.

Biomass as a major component of pellets

The article describes the quality parameters of the selected elements of biomass as a potential ecological biofuel. Several selected elements of a type of biomass were tested to determine the calorific value, humidity, content of sulfur and amount of ash produced in burning process. The concept of biomass and the legal aspects of its combustion are described. The research of biomass samples revealed that they may be turned into a high-energy, ecologically solid biofuel. Production of biofuel from the tested biomass does not require any additional binders. Studies have shown that the tested material can also act as a component of composite pellets. The quality parameters of such pellets can be determined with the composite calculator that is described in this article. The article also describes the technical aspects of the pellet production line, which should be applied to produce good-quality pellets from the tested types of biomass.

Pilot scale evaluation of fuel pellets production from garden waste biomass

Pelletization of garden waste, without additional binder, was investigated to produce high quality fuel pellets for energy utilization. The influence of pelletization parameters viz. feedstock moisture content (5, 15, 25, and 35%), milling size (25.4 and 6.25mm) and die size (12 and 15mm) on pellet quality and pelletization process was studied. The results showed that the studied parameters had significant effect on pellet quality. A reduction in average durability value (95.0% to 92.5%) was observed when moisture content of garden waste increased from 5% to 15%. Appropriate regression models were also developed for each quality attribute by using multiple linear regressions. Eventually, a feedstock moisture content of 5±1%, milling size of 6.35mm and die size of 15mm were found to offer standard quality pellets with optimum throughput capacity. Scanning electron microscopy image analysis showed a closer agglomeration of biomass particles when feed materials were pelletized at low moisture content. The equilibrium moisture content due to adsorption for garden waste pellet was found to be 14.6% which was quite low as compared to other feedstocks. Furthermore, we deduced from the combustion test that garden waste pellets may be conveniently used in a residential cookstove. In a nutshell, pelletization of garden waste biomass has been demonstrated at pilot scale in this study.

Co-pelletization of sewage sludge and agricultural wastes

This paper concerns the process of production and properties of pellets based on biomass wastes. Co-pelletization was performed for sewage sludge from municipal wastewater treatment plant and other biomass material such as animal and olive wastes.The aim of the present study was to identify the key factors affecting on the sewage sludge and agricultural residues co-pelletization processes conditions. The impact of raw material type, pellet length, moisture content and particle size on the physical properties was investigated. The technic and technological aspects of co-pelletization were discussed in detail.The physical parameters of pellets, i.e.: drop strength, absorbability and water resistance were determined. Among others, also energy parameters: low and high heat value, content of ash and volatiles were presented.Results showed the range of raw materials moisture, which is necessary to obtain good quality biofuels and also ratio of sewage sludge in pelletizing materials.The analysis of the energetic properties has indicated that the pellet generated on the basis of the sewage sludge and another biomass materials can be applied in the processes of co-combustion with coal. Those biofuels are characterised with properties making them suitable for use in thermal processes and enabling their transport and storage.

Combined effects of torrefaction and pelletization parameters on the quality of pellets produced from torrefied biomass

A combined torrefaction and pelletization study was performed at industrially relevant settings using a factorial design. First, wood chips of Scots pine were torrefied at high temperatures (291–315°C) and short residence times (6–12min), facilitating high throughput in a continuous pilot-scale torrefaction process. Then the torrefied materials were pelletized, also in pilot-scale, using varying moisture contents (MCs) (10–14%), sieve sizes (4–6mm), and press channel lengths (PCLs) (25 and 30mm), in all 19 batches, each of 400kg. The resulting so called black pellets exhibited bulk densities of 558–725kgm−3, durabilities of 46.3–86.5%, and fines contents of 3.8–85.8%.Through multiple linear regression modelling of all 11 responses, it was found that the parameter with the greatest influence on the responses was the torrefaction temperature, followed by torrefaction time, MC, and PCL. Longer PCL and higher MC resulted in higher pellet quality, with less fines and greater bulk density and durability. Furthermore, a low torrefaction degree decreased the amount of power required for pelletization. The energy required to grind pellets into a powder (<0.5mm) decreased with increasing torrefaction degree as expected, but also with decreasing MC before pelletizing. Pyrolysis-GC/MS analysis of thermal degradation products from the pellets revealed correlations with the torrefaction temperature and time, but no correlations with the pelletization process.These results are useful for mapping chemical changes in torrefied materials and identifying complementary torrefaction and pelletization settings. Specifically of interest is adjustment of PCLs at low intervals to better match friction properties of torrefied materials.

Injection barrel with a tapered structure for a low speed and small size cryogenic hydrogen pellet in medium-sized plasma fusion devices.

An injection barrel was designed and fabricated for a small size 0.8 mm cryogenic pellet with a low speed of 200-300 m/s in medium-sized plasma fusion devices. Pellet injection with pneumatic acceleration was examined using a conventional in situ technique. A tapered structure was applied in the downstream side of the injection barrel to satisfy the requirement of pellet speed reduction by expansion of the propellant gas. Shadowgraph and light gate measurements show that the intact pellets have speeds of 260 ± 30 m/s and a typical size of 1.1-1.2 mm. The pellet ablation code based on a neutral gas shielding model shows that the penetration depth of the measured pellet parameters does not cross the plasma center, even in medium-sized plasma devices such as the Heliotron J helical device. The injection barrel with a tapered structure developed in this study is feasible for low speed pellet injection.

Optimize preparation parameters of colon-specific pellets of Angelica Sinensis Radix supercritical fluid extraction with response surface analysis methodology

To prepare pellets of supercritical fluid extraction (SFE) of Angelica Sinensis Radix by using the ionic crosslinking method, and the drug loading and encapsulation efficiency were used as the index to investigate the multiple factors which may impact the drug loading and encapsulation efficiency. Box-Behnken design and response surface analysis method were then taken to optimize the prescription of pellets and study the coating technology. Through the study on the release of pellets in vitro, an optimal coating technology and prescription of colon-specific pellets of Angelica Sinensis Radix SFE were selected and their colon targeting was evaluated. The optimal preparation parameters of pellets were determined as follows： 3% pectin; 4∶1 for pectin/lecithin; 4∶5 for pectin/SFE of Angelica Sinensis Radix; 4% zinc acetate solution as crosslinking agent, blending temperature 35 ℃, crosslinking temperature 35 ℃, crosslinking time 30 min; coating technology： coating material Eudragit FS 30D, 1.5% triethyl citrate and polyoxyethylene sorbitan monooleate（tween-80）, 1.2% monostearin and 15% coating weight gained. The colon-specific pellets of Angelica Sinensis Radix SFE prepared with optimized conditions were almost not released in simulated gastric fluid in 2 h, released less than 20% in simulated intestine fluid in 4 h, and released more than 90% in simulated colon fluid in 6 h, indicating that the colon-specific pellets of Angelica Sinensis Radix SFE had an excellent colon targeting property.

Selecting key parameters of the green pellets and lightweight ceramic proppants for enhanced shale gas exploitation

Ceramic proppants are classified as propping agents commonly used for the shale gas industry. Fractures created in shale deposits due to high fluid pressure (hydraulic fracturing) have to be propped allowing unconventional gas migration to a borehole. Ceramic granules located in the newly created fissures act as a prop so that the shale gas can flow up the well. It occurs if the proppants can resist the huge forces of the closing fractures at high temperature. Due to these strict geological conditions and processing requirements the proppants have to be characterized by proper physico- mechanical properties. The aim of this research was to study, compare and select the ceramic proppants characterized by the most appropriate parameters. The investigation relates to the industrial granules obtained by the mechanical granulation method and afterwards sintered which were confronted and analyzed. Utility of the proppants was estimated basing on bulk density and roundness coefficient. Structure, morphology and chemical composition of the samples were determined by the Scanning Electron Microscopy (SEM) with Energy Dispersive Spectroscopy (EDS). The sintered proppants were also characterized with X-Ray Tomography, turbidity and solubility in acid additionally. The crucial parameter as mechanical strength was established during the propping samples subjection to the crush tests. The obtained outcomes prove that chemical composition, pores distribution, grain size and mechanical strength influence the integrity of created fractures and therefore the extraction of the unconventional gas out of the well.

The investigation of particle flow mechanisms of bulk materials in dustiness testers

ABSTRACTThe generation of dust occurs in many bulk materials handling applications, including during free-fall, material impact on conveyor transfers, or impact with other materials. Dust has potentially serious consequences to the surrounding environment as well as workers and nearby communities. Companies need to identify and quantify the dust being generated so they can find ways to reduce or eliminate this dust generation. Dustiness testers are one method which can be used to quantify dust generation. This paper investigates the experimental material flow and the subsequent discrete element method (DEM) simulation in the rotating drums of two dustiness testers: the European Standard dustiness tester and the Australian Standard dustiness tester. Preliminary comparisons of the rotating drum designs were undertaken using particle/bulk parameters of polyethylene pellets, a granular “non-dusty” material to investigate the flow behavior, to provide a reference base to compare equivalent simulations and subsequent analysis. A calibrated DEM material model for polyethylene pellets was generated via experimental comparison. Investigations of the rotational speed, volume, and initial loading location of product sample have been performed. The motion of particles in the simulated rotating drums has been compared to visual observation from experimental testing.

Semi-continuous feeding and gasification of alfalfa and wheat straw pellets in a lab-scale fluidized bed reactor

Small scale air-blown fluidized bed gasification of alfalfa and wheat straw pellets were conducted for semi-continuous solid feeding and range of operating conditions varied due to the modifications in equivalence ratio (ER) (0.20–0.35) achieved both by varying solid and air input. Alfalfa pellets displayed an improvement in several gasification variables such as gas lower heating value (∼4.1MJ/Nm3), specific gas yield (1.66Nm3/kg), cold gas efficiency (∼42%) and carbon conversion efficiency (∼72%) as ER maximized to 0.35 which was found optimum for this feedstock for the present course of experiments. Gasification parameters of wheat straw pellets on the other hand were characterized by a great degree of variation as the ER progressively increased. The optimum performance of this biomass was likely to achieve at ER=0.30 when gas lower heating value and cold gas efficiency maximized to ∼4MJ/Nm3 and ∼37% respectively. Moreover, a substantial drop in tar yield (58.7g/Nm3) at this ER was also indicative to the optimal thermal conversion at this point of operation. Overall, both the feedstocks presented promising alternatives for utilization into the small-scale fluidized bed gasification which is increasingly emerging as a sustainable solution towards processing lignocellulosic biomass.

Ultrasonic vibration-assisted pelleting for cellulosic biofuels manufacturing: A study on in-pellet temperatures

Cellulosic biofuels have been proposed to replace part of traditional liquid transportation fuels. Cellulosic biomass is the feedstock in cellulosic biofuel manufacturing. Costs associated with collection and transportation of cellulosic biomass account for more than 80 percent of the feedstock cost [1]. By processing cellulosic biomass into pellets, energy density and handling efficiency of cellulosic feedstock can be improved, resulting in reduction of transportation and handling costs. Ultrasonic vibration-assisted (UV-A) pelleting is one of important pelleting process which can make high quality pellets efficiently. The literature on UV-A pelleting covers studies about effects of input process parameters on pellet density, durability, sugar yield, charring, and pelleting force, but has little information about pelleting temperature. This paper presents an experimental investigation on effects of input variables on pelleting temperature. The pelleting temperatures at the different locations of a pellet were measured during pelleting using metal wire-typed thermocouples. Several pelleting parameters were varied to study their effects on pelleting temperature. Results obtained will be helpful in understanding why pelleting parameters affect pellet quality (density and durability), charring, and sugar yield.