Thermal Processing Systems Research Articles

ГЕЛИОПИРОЛИЗНАЯ УСТАНОВКА ДЛЯ ПОЛУЧЕНИЯ АЛЬТЕРНАТИВНЫХ ТОПЛИВ ИЗ БИОМАССЫ И ОРГАНИЧЕСКИХ ОТХОДОВ СЕЛЬСКОГО ХОЗЯЙСТВА

The analysis of scientific research has been carried out, which presents technologies for processing biomass and agricultural organic waste based on solar energy, providing alternative fuels for solving energy saving problems of autonomous consumers. (Research purpose) The research purpose is developing and substantiating the main parameters of a heliopyrolysis plant with a parabolic solar concentrator for producing alternative fuels from biomass to meet the domestic needs of rural homes and farms. (Materials and methods) Analyzed the thermal and technological schemes of existing pyrolysis plants, thermal biomass processing systems and their energy intensity. A technological scheme of a heliopyrolysis plant with a parabolic solar concentrator has been developed. Based on the developed technological scheme, the design of an experimental heliopyrolysis installation with a parabolic solar concentrator was created. A methodology for conducting experimental studies on pyrolysis of biomass and organic waste using concentrated solar energy has been developed. (Results and discussion) Based on the results of experiments, it was shown that as a result of pyrolysis of 1 kilogram of rubber waste loaded into the reactor of the installation, 20 percent of liquid and 35 percent of gaseous fuels were obtained, 34 percent of coal, 10 percent of liquid and 56 percent of gaseous fuels were obtained from the same amount of chicken manure, 55 percent of liquid and 45 percent of gaseous fuel, from plant waste (cotton stalks) - 34 percent of coal, 26 percent of liquid and 40 percent of gaseous fuel. (Conclusions). It was found based on the results of the scientific research carried out and the technical and economic calculations carried out that the use of a parabolic solar concentrator in pyrolysis installations made it possible to increase the energy efficiency of the installation by 10-12 percent. It was determined that within one year, having processed 1.0 ton of biomass using a heliopyrolysis unit with a parabolic solar concentrator, it is possible to obtain 300-350 cubic meters of gaseous fuel, 350-400 kilograms of pyrolysis liquid, 200-300 kilograms of charcoal.

Effects of Pulsed Electric Fields and Ultrasound Processing on Proteins and Enzymes: A Review

There is increasing demand among consumers for food products free of chemical preservatives, minimally processed and have fresh-like natural flavors. To meet these growing demands, the industries and researchers are finding alternative processing methods, which involve nonthermal methods to obtain a quality product that meets the consumer demands and adheres to the food safety protocols. In the past two decades’ various research groups have developed a wide range of nonthermal processing methods, of which few have shown potential in replacing the traditional thermal processing systems. Among all the methods, ultrasonication (US) and pulsed electric field (PEF) seem to be the most effective in attaining desirable food products. Several researchers have shown that these methods significantly affect various major and minor nutritional components present in food, including proteins and enzymes. In this review, we are going to discuss the effect of nonthermal methods on proteins, including enzymes. This review comprises results from the latest studies conducted from all over the world, which would help the research community and industry investigate the future pathway for nonthermal processing methods, especially in preserving the nutritional safety and integrity of the food.

Energy and exergy analysis of induction-assisted batch processing in food production: a case study—strawberry jam production

Traditional and additive free conservation techniques for long shelf life of fruits can be counted as drying and canning or processing to jam–marmalade. Conventional systems consume fuel or electricity to produce required energy with low efficiency due to losses and irreversibilities through heat transfer. For strawberry jam production, heat is applied as a batch system by vacuum-jacketed agitated vessel with a water or heating oil (heat transfer fluid—HTF), which is heated by electricity inside the jacket. In this study, energy and exergy efficiencies of conventional jacketed vessels and inductive heater were compared theoretically for jam processing. It is found that water and HTF used systems works with 82.27% and 93.38% energy efficiencies, respectively, while inductive processing system works with 95.00% efficiency. In terms of irreversibilities, the inductive system generates 79.90 kJ K−1 entropy, while other systems generate 674.19 kJ K−1 for HTF system and 753.90 kJ K−1 for the water system. It is determined that the batch system with induction heater needs less energy and exergy input than conventional electrical heater systems to provide the same desired output. Direct heating by induction heater has several benefits at thermal food processing systems as strawberry jam production by lowering energy and exergy losses.

Slow Mode-Based Control Method for Multi-Point Temperature Control System

In recent years, thermal processing systems with integrated temperature control have been increasingly needed to achieve high quality and high performance. In this paper, responding to the growing demands for proper transient response and to provide more accurate temperature controls, a novel slow-mode-based control (SMBC) method is proposed for multi-point temperature control systems. In the proposed method, the temperature differences and the transient response of all points can be controlled and improved by making the output of the fast modes follow that of the slow mode. Both simulations and experiments were carried out, and the results were compared to conventional control methods in order to verify the effectiveness of the proposed method.

Unsteady free convective heat transfer in third-grade fluid flow from an isothermal vertical plate: A thermodynamic analysis

The current study investigates theoretically and numerically the entropy generation in time-dependent free-convective third-grade viscoelastic fluid convection flow from a vertical plate. The nondimensional conservation equations for mass, momentum and energy are solved using a Crank–Nicolson finite difference method with suitable boundary conditions. Expressions for known values of flow-variables coefficients are also derived for the wall heat transfer and skin friction and numerically evaluated. The effect of Grashof number, Prandtl number, group parameter (product of dimensionless temperature difference and Brinkman number) and third-grade parameter on entropy heat generation is analyzed and shown graphically. Bejan line distributions are also presented for the influence of several control parameters. The computations reveal that with increasing third-grade parameter, the entropy generation decreases and Bejan number increases. Also, the comparison graph shows that contour lines for third-grade fluid vary considerably from the Newtonian fluid. The study is relevant to non-Newtonian thermal materials processing systems.

Модель комплексного управления рисками при обеспечении ресурсо- и энергосбережения процессов на примере сложных теплотехнологических систем

Under the conditions of constantly growing complexity of the processes used in technological systems, the main risk management tasks cannot be solved by using the traditional methods implying exact representation of problem situations. This is because such tasks are characterized by a large number of parameters, uncertainty and data ambiguity. The external environmental conditions for such systems are characterized by instability and uncertainty, which are caused, on the one hand, by high variability of the external environment and, on the other hand, by uniqueness of the emerging problem situations. The problem is formulated, and a cascade-composition integrated risk management model in setting up resource and energy saving processes is proposed taking complex thermal processing systems (CTPS) as an example. The proposed model is based on a fuzzy approach and on fuzzy model hybridization and integration methods. The need for comprehensively managing the risks in setting up resource and energy saving processes in a CTPS is primarily stemming from the requirement of keeping the violation risks within the acceptable level. It should be noted that the acceptable level of risk can be established not only for violation of technological processes in a CTPS as a whole, but also for all stages and for individual technological processes. The proposed cascade-composition model includes fuzzy models for carrying out a component-wise analysis of the technological processes in the CTPS, for estimating the resource and energy efficiency of technological processes, and for assessing the risks in setting up resource and energy savings. The article describes an approach to solving the problem of integrated risk management in setting up resource and energy saving processes in the CTPS using the proposed model. The approach implies specification of different combinations of control parameters at each stage for all technological processes with taking into account all constraints imposed on these processes, and modeling and determining the combinations of control parameters that will make it possible to improve the resource and energy efficiency of technological processes in the CTPS while keeping the violation risks within the acceptable level. The article presents the experimental results of integrated risk management in setting up resource and energy savings using the proposed model and approach taking as an example the process of drying phosphate pellets in the calcining conveyor machine. The obtained results are supposed to be used for integrated risk management in setting up resource and energy saving for various processes in CTPSs.

Non‐thermal technologies and its current and future application in the food industry: a review

SummaryIn recent years, consumers have been demanding convenient and healthy foods which have ‘fresh‐like’ characteristics while still being safe and a long shelf‐life. These requirements are hard to achieve using existing traditional thermal food processing technologies and the innovative new food process and preservation technologies based on thermal processing systems are needed. However, non‐thermal technologies in food processing do not generate high temperature and use short treatment times. This means that the nutritional components of foodstuffs are better retained, and the sensory properties of foods are less changed compared with traditional thermal processing. The aim of this review was to present non‐thermal technologies applications and its mechanism in food industry in recently, and to explore the potential application prospects of combining non‐thermal treatments applied in food industry because it not only could overcomes the drawback of single technology, but also can enhances the processing efficiency at lower treatment intensity.

Gasification reactivity and synergistic effect of conventional and microwave pyrolysis derived algae chars in CO2 atmosphere

This research focuses on the isothermal and non-isothermal CO2 gasification of an algal (Chlorella) char prepared via two different thermal processing systems, i.e. conventional and microwave-assisted pyrolysis. It was found that chars prepared via microwave irradiation showed higher CO2 gasification reactivity than that of chars prepared via the conventional method. Meanwhile, the activation energy of microwave char was found to be 127.89 kJ/mol, which was 46.3 kJ/mol lower than that of conventional char, indicating improved reactivity of microwave char. The systematic characterisation of both conventional and microwave chars shows that the higher reactivity of microwave char could be attributed to its large BET surface area, low crystalline index and high active sites. In addition, it was found that microwave heating contributed to high reactivity of chars through generating large amount of primary char, the formation of hot spot and high specific surface area and pore volume. Results of co-gasification under isothermal conditions revealed the existence of greater synergistic effects between coal char and microwave algae char than those of coal char and conventional algae char. Furthermore, based on the relative Rs (average gasification rate), a novel index proposed to quantify the interactions in co-gasification process, Australian coal char/microwave assisted char blend experienced 10% higher interactions compared to Australian coal char/conventional assisted char blend.

Research on the Architecture and Behavior Model of High-Speed Channel for Thermal Image Processing

The architecture description and behavior model from top-level to bottom-level with Architecture Description Language (ADL) have been put forward, as well as the infrared thermal image processing systems designed by author. The module of infrared high-speed channel is set up by means of Unified Modeling Language, Finite State Machine and Petri net, and their simulation results of logic synthesis with Hardware Description Language for digital video codec, Horizontal/Vertical, field/line synchronization and FIFO buffer are presented.

Linear Parameter-varying Approach for Modeling and Control of Rapid Thermal Processes

In the present paper, a new approach is presented to model and control single wafer rapid thermal processing (RTP) systems. In the past decade, RTP has achieved acceptance as the mainstream technology for semiconductor manufacturing. Thermal processing is one of the most efficient ways to control the phase-structure properties. Moreover, the time duration of RTP systems reduces the so-called thermal budget significantly compared to the traditional methods. RTP implementation is based on the use of light from heating lamps to provide a heat flux. This process is highly nonlinear due to the radiative heat transfer and material properties. By invoking the first principles-based models, we develop in this paper a linear parameter-varying (LPV) model to directly account for the nonlinearities within the system. The model is then discretized into a high-order LPV model; thereafter, principal component analysis (PCA) method is utilized to reduce the number of LPV model’s scheduling variables, followed by the use of proper orthogonal decomposition (POD) for model order reduction. Using the reduced order model, we then design a gain-scheduled controller to satisfy an induced L2 gain performance for tracking of a temperature profile and show improvement over other controller design methods suggested in the literature.

Heat transfer phenomena during thermal processing of liquid particulate mixtures—A review

ABSTRACTDuring the past few decades, food industry has explored various novel thermal and non-thermal processing technologies to minimize the associated high-quality loss involved in conventional thermal processing. Among these are the novel agitation systems that permit forced convention in canned particulate fluids to improve heat transfer, reduce process time, and minimize heat damage to processed products. These include traditional rotary agitation systems involving end-over-end, axial, or biaxial rotation of cans and the more recent reciprocating (lateral) agitation. The invention of thermal processing systems with induced container agitation has made heat transfer studies more difficult due to problems in tracking the particle temperatures due to their dynamic motion during processing and complexities resulting from the effects of forced convection currents within the container. This has prompted active research on modeling and characterization of heat transfer phenomena in such systems. This review brings to perspective, the current status on thermal processing of particulate foods, within the constraints of lethality requirements from safety view point, and discusses available techniques of data collection, heat transfer coefficient evaluation, and the critical processing parameters that affect these heat transfer coefficients, especially under agitation processing conditions.

Dielectric properties of bentonite water pastes used for stable loads in microwave thermal processing systems

The dielectric properties of bentonite water pastes relevant to microwave thermal processing were measured over 300–3000MHz and 22–120°C. Effects of bentonite content (7.5–25%, wb), salt (NaCl) content (0.3–1.2%, wb), vegetable oil content (5–15%, wb) and sucrose content (30%, wb) on dielectric properties were investigated. Regression equations were developed to reveal the influences of temperature and different ingredients on the dielectric properties of bentonite pastes at 915 and 2450MHz. Results illustrated that dielectric properties of bentonite pastes could be adjusted with different ingredients to match those of a wide range of food materials with similar response to increasing temperature. Vegetable oil and salt were good additives to reduce dielectric constant and increase loss factor, respectively. Adding sucrose reduced both dielectric constant and loss factor. Derived from the regression equations, the influence factor of each ingredient was calculated to reveal its influence on the changing rate of dielectric properties with increasing temperature. The bentonite pastes can be formulated with stable dielectric properties and be used as dummy loads for evaluating performance of industrial microwave assisted thermal processing systems.

Evaluation of the differences of process variables in vertical and horizontal configurations of High Pressure Thermal (HPT) processing systems through numerical modelling

High Pressure Thermal (HPT) processing of foods is a preservation technology which satisfies consumer demand for high-quality products. Numerical modelling can be used to predict locally specified temperature profiles arising during HPT processing, which is very important in order to ensure microbiological food safety and quality. To date all of the models developed and published on prediction of temperature and flow distribution are based on, to the best of our knowledge, vertically oriented HPT units. However, because of the increase of horizontal units in industry, and the lack of published work on horizontal models, it was seen important to bridge this research gap in order to advance the technology further. In this work a horizontal model was developed by adapting a previously validated vertical one. It was shown that the temperature performance and uniformity is different for the two configurations, indicating that the research conducted on vertical systems is not directly transferable to horizontal systems in HPT processing.

Safety of the Surrogate Microorganism Enterococcus faecium NRRL B-2354 for Use in Thermal Process Validation

Enterococcus faecium NRRL B-2354 is a surrogate microorganism used in place of pathogens for validation of thermal processing technologies and systems. We evaluated the safety of strain NRRL B-2354 based on its genomic and functional characteristics. The genome of E. faecium NRRL B-2354 was sequenced and found to comprise a 2,635,572-bp chromosome and a 214,319-bp megaplasmid. A total of 2,639 coding sequences were identified, including 45 genes unique to this strain. Hierarchical clustering of the NRRL B-2354 genome with 126 other E. faecium genomes as well as pbp5 locus comparisons and multilocus sequence typing (MLST) showed that the genotype of this strain is most similar to commensal, or community-associated, strains of this species. E. faecium NRRL B-2354 lacks antibiotic resistance genes, and both NRRL B-2354 and its clonal relative ATCC 8459 are sensitive to clinically relevant antibiotics. This organism also lacks, or contains nonfunctional copies of, enterococcal virulence genes including acm, cyl, the ebp operon, esp, gelE, hyl, IS16, and associated phenotypes. It does contain scm, sagA, efaA, and pilA, although either these genes were not expressed or their roles in enterococcal virulence are not well understood. Compared with the clinical strains TX0082 and 1,231,502, E. faecium NRRL B-2354 was more resistant to acidic conditions (pH 2.4) and high temperatures (60°C) and was able to grow in 8% ethanol. These findings support the continued use of E. faecium NRRL B-2354 in thermal process validation of food products.

Multisensorial Self-learning Systems for Quality Monitoring of Carbon Fiber Composites in Aircraft Production

Currently in the aerospace industry is a change from the traditional nest production towards an automated mass production, which requires the fulfillment of very high demands on precision and availability of the new technologies. In a research cooperation between industrial companies and research institutions skills were developed for an automated production of carbon fib er composite parts for aircraft industries.A major challenge of the project was the enormous demands on the quality and the necessary evidence. While in automotive industries quality control will normally be carried out by samples, in the aircraft industry a 100%-monitoring is necessary to assure the safety of the aircraft and to reduce financial risks for the involved enterprises.The manufacturing process of assembling the wing-cover components made of carbon fiber composite – titanium/aluminum structures consists primarily of the operations of drilling, reaming, removal of temporary rivets and placing the final rivets. With about 5,000 rivets the correct and flawless insertion of the holes is extremely important.Therefore a core area of the project was the line quality monitoring of a damage-free drilling of carbon-fiber composites. This included the automated measurement of all holes with respect to diameter, roundness and chamfer angle, but also the identification of possible delamination between layers of carbon fiber composites.Since the potential defects are not detectable using a single physical system, a platform for an open-system combination of various physical processes such as thermal imaging sensors, image processing and laser scanning systems was developed. In this way it is possible to compensate the disadvantages of the individual systems through the added properties of the corresponding systems.Via the developed system, the relevant features can be extracted from the raw data and fed into a generic rating classification system and a learning process. The addition of other sensor systems, such as eddy current or ultrasonic sensors, is possible at any time.The solution is based on a tripartite division of the data processing: data recording from almost any data acquisition system, data preprocessing for extracting the relevant features from the raw data and the classification system that performs the mapping of the data for the predefined and learned classes. As mathematical basis matrix operations, methods of exploratory data analysis (i.e. component analysis) and different classification methods (MLDA, MLP) are used.The paper shows the mathematical and technical procedures, explains the experimental conditions and shows the obtained results in detail.

Carbon Dioxide Balance and Cost Analysis for Different Solid Waste Management Scenarios

In order to determine the optimal final destination of municipal solid waste, it is necessary to consider both monetary costs and environmental externalities, such as carbon balance and GHG production, as well as the local availability of waste-processing industrial infrastructure. In order to develop a strategy for the selection of the optimal waste management system, in the present work we consider a specific city located in Piedmont (northern Italy). The volume of municipal solid waste produced in the city is about 540,000 ton/year. To determine the best method for management and disposal of this volume, we considered three different scenarios, using the best available technologies. The scenarios included the use of both thermal processing systems (incineration and gasification plants) and other systems (mechanical separation plants, anaerobic digestion plants). The scenarios were analyzed and compared, considering environmental, construction and operating costs, in order to develop a model for making an objective comparison. The results of the analysis for this specific case revealed that direct combustion in an incineration plant delivered the best outcome for both environmental impacts and economic convenience. More generally, the comparison methodology for the scenarios can be a useful approach for determining the best solution for waste management planning for a specific locality.

Nonlinear control strategy for thermal budget in spike rapid thermal processing systems based on Wiener model

ABSTRACTThe spike‐shaped temperature profile in thermal treatments is widely used in semiconductor manufacturing for providing precise thermal budget. This thermal budget control issue gets more crucial as the technology node progressively shrinks. Therefore, rapid thermal processing (RTP) with spike‐shaped temperature profile, such as spike annealing, has the ability to meet this requirement. With its exceptionally stringent performance requirements (e.g. high temperature ramp‐up/down rate and high temperature uniformity), temperature control in RTP systems is a challenging task. Our previous work proposed a methodology of control system design which can precisely target the thermal budget indices. The major problem in that work is that a linear model of the RTP system is assumed, but the dynamics of RTP system is, in fact, nonlinear in nature. In this study, we extend the previous work by considering the nonlinearity of the RTP system. First, a nonlinear Wiener model, instead of linear model, is used to represent the RTP system. For this purpose, a simple noniterative algorithm for the identification of Wiener model is proposed. Then, a simple nonlinear control strategy based on the Wiener model is developed for providing precise thermal budget. Simulation results have shown that the proposed method performs well in spike RTP systems. © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.

Enhancement of the electrical characteristics of MOS capacitors by reducing the organic content of H2O-diluted Spin-On-Glass based oxides

Abstract In this work, the physical, chemical and electrical properties of Metal-Oxide-Semiconductor (MOS) capacitors with Spin-On-Glass (SOG)-based thin films as gate dielectric have been investigated. Experiments of SOG diluted with two different solvents (2-propanol and deionized water) were done in order to reduce the viscosity of the SOG solution so that thinner films (down to ∼20 nm) could be obtained and their general characteristics compared. Thin films of SOG were deposited on silicon by the sol–gel technique and they were thermally annealed using conventional oxidation furnace and Rapid Thermal Processing (RTP) systems within N 2 ambient after deposition. SOG dilution using non-organic solvents like deionized water and further annealing (at relatively high temperatures ≥450 °C) are important processes intended to reduce the organic content of the films. Fourier-Transform Infrared (FTIR) Spectroscopy results have shown that water-diluted SOG films have a significant reduction in their organic content after increasing annealing temperature and/or dilution percentage when compared to those of undiluted SOG films. Both current–voltage ( I – V ) and capacitance–voltage ( C – V ) measurements show better electrical characteristics for SOG-films diluted in deionized water compared to those diluted in 2-propanol (which is an organic solvent). The electrical characteristics of H 2 O-diluted SOG thin films are very similar to those obtained from high quality thermal oxides so that their application as gate dielectrics in MOS devices is promising. Finally, it has been demonstrated that by reducing the organic content of SOG-based thin films, it is possible to obtain MOS devices with better electrical properties.

Simulation of pattern effect induced by millisecond annealing used in advanced metal-oxide-semiconductor technologies

The submelt millisecond annealing process was introduced in the context of complementary metal-oxide semiconductor technology downscaling to enhance the activation of dopants. However, circuit designs can produce nonuniform local radiative and thermal dispersion properties at the front side of a wafer. Nonuniformities lead to local variations in annealing temperature and, therefore, to variability in device electrical properties and performance. This so-called pattern effect, well known in the context of lamp-based rapid thermal processing systems, is investigated here by simulation of the annealing process on the millisecond time scale. The multiphysics simulation models both optical and thermal properties. Real design inputs were imported from layout files and a finite element method simulation was used to compute transient temperature fields during the process. The absorptivities of a variety of periodic patterned structures were investigated by optical modeling. The radiative and thermal properties of the devices were mapped at the circuit scale. Finally, a three-dimensional thermal simulation was performed to evaluate the intradie thermal dispersions, which were found to be as large as 45°C in the real system.

Efficient Signal Transport Model for Remote Thermometry in Full-Scale Thermal Processing Systems

The rapid thermal processing of semiconductor devices is very temperature sensitive and requires precise temperature measurement. Light pipe radiation thermometers are widely used for temperature control during manufacturing by industry, and there is concern about errors associated with light pipe measurements. Modeling in simplified systems has helped in understanding the signal transport process in light pipes and errors associated with measurements in the past. Considering the small sensor area compared to the size of the semiconductor wafer and the remaining system components, modeling of the complete system has not been done due to the computational demand. A reverse Monte Carlo model can be used efficiently to model the signal transported to the photodetector in conjunction with a thermal model of the system to better characterize the system. The proposed method is demonstrated in a full-scale instrumented system with a light pipe thermometer, and the results are compared against previously published measurements from the system.