Oven Systems Research Articles

Effect of microwave and oven roasting on chemical composition, bioactive properties, phenolic compounds and fatty acid compositions of sunflower seed and oils

AbstractIn this study, the effects of microwave (540, 720 and 900 W) and oven (120, 150 and 230°C) roasting techniques on the total phenolics, flavonoids, antioxidant capacity, polyphenolic and fatty acid results of sunflower seed and oils were investigated. Total phenol (except oven 150°C), flavonoid (except oven 120°C) contents and antioxidant activity values of sunflower seeds and oils subjected to oven and microwave heat treatment decreased compared to the control. Total phenolic, total flavonoids and antioxidant activities were higher in MRS oil than ORS oil. Individual phenolic constituent in both seed and oil samples from ORS and MRS showed significant (p < 0.05) changes to the control (non‐roasted seed and its oil). A general increase in the phenolic components of seeds and oils was observed with oven and microwave roasting compared to the control. Oleic acid values (%) of the oil extracted from seeds roasted in oven and microwave systems were recorded to be between 23.76 (120°C) and 29.41% (150°C) to 24.32 (540 W) and 26.10% (720 W), respectively. Linoleic acid values of the oils obtained from seeds roasted in oven and microwave systems varied to be between 57.01 (150°C) and 65.89% (120°C) to 60.70 (720 W) and 65.26% (540 W), respectively. As a result of the applied heat treatment, while the linoleic acid values of the oil samples decreased, an increase was observed in the palmitic, stearic and oleic acid values of the oil.

A novel hierarchical temperature control method of an electric oven and its experimental evaluation

PurposeOvens are semi-industrial multipurpose equipment that are used to provide a desired temperature for specific chemical processes. Temperature regulation in the presence of different type of disturbances and dealing with nonlinear dynamics with large dead time (up to a few minutes) are some undesirable factors that have to be considered in the controller design procedure of the oven systems. Due to these factors, the classical PID controller tuned using Cohen-Coon or Ziegler–Nichol’s tuning methods often fails to meet satisfactory closed-loop performance.Design/methodology/approachIn this paper, to deal with the limitations on the oven system due to the undesirable factors, a hierarchical automaton-guided form controller has been designed. The proposed controller includes several discrete PI controllers, each of which operates locally in the defined operating regions whose separation idea is specific to this paper. Based on the idea proposed in the separation of regions, the controller’s coefficients tuning rules are extracted prior to any determination. Then, a supervisor controller has assumed the task of switching between local controllers. In the next step, by considering a conceptual model for the oven system and using a candidate Lyapunov function, the stability conditions of closed-loop system are discussed and the necessary conditions for the asymptotic stability are derived. The proposed controller is practically implemented with the help of the Arduino Nano platform.FindingsUsing several experiments, the superiority of the proposed hierarchical controller in terms of performance and energy consumption has been demonstrated.Originality/valueThe proposed hierarchical controller has been implemented practically and an acceptable closed-loop performance has been achieved. To illustrate the efficiency of the proposed method, the closed-loop stability of this method is shown using the Lyapunov theory.

A real-time cost optimization of two-section oven system with discrete gradient extremum seeking control: An experimental study in iron and steel industry

The heavy industry plants are focused on finding ways to minimize energy costs, which is one of the most significant costs of production. In this paper, a case study on a real oven system used in a steel strip production line is performed. Oven systems consume different types of energy simultaneously. Therefore, energy cost optimization is a good case study for the oven systems. The real oven system studied in the present study consists of two sections with eight heating zones. A natural gas burner and a recirculation fan with a power of 45 kW are installed in each zone for continuous heating of steel strips. We improved Discrete Gradient Extremum Seeking Control (DGESC) in the oven system without changing the oven structure and its built-in burner controller and optimized the fan speeds so that the total cost of the heating process is minimized. The improved DGESC was evaluated during steel strip production with the constraints related to the oven safety, measurement device characteristics, and delays for stabilization. The measure of energy consumption was obtained from the oven automated software and compared with the consumption when using the oven manufacturer’s recommended settings. At the end of the production, the improved DGESC strategy showed that the same output can be produced with less cost at different operating speeds of the fans. In particular, the total cost of the electrical energy and natural gas was reduced by 3.44% when using 78% of fan speed instead of using 70% recommended by the manufacturer. The promising results of the improved DGESC can be further enhanced by upgrading the oven system for individual measurements.

Evaluation of baking performance by means of mid-infrared imaging

The present work aims to validate mid-infrared imaging as a promising method for evaluating oven systems. Therefore, a novel approach by analyzing mid-infrared radiation patterns captured by a thermal camera and subsequent image processing was developed. A thermal camera was adapted to two different oven systems: a standard electric deck oven and a novel gas-fired baking oven with integrated volumetric ceramic burners (VCBs). The baked goods were analyzed and key indicators describing the final product quality were determined. Specific volume, surface browning and mid-infrared image processing demonstrated a comparable performance of both oven systems. Furthermore, the determined surface heat homogeneity of the items to be baked was 0.65 ± 0.05 (–) for the electronic oven and 0.70 ± 0.03 (–) for the VCB oven. The proposed approach proved its fundamental qualification for comparing and evaluating different oven systems.

Reliability Testing and Stress Measurement of QFN Packages Encapsulated by an Open-Ended Microwave Curing System

In this paper, the influence of microwave curing on the reliability of a representative electronic package is examined by reliability testing and measurement of residual stresses. A LM358 voltage regulator die was mounted to an open quad flat no-leads (QFN) package for reliability testing. For the stress measurement, a specifically designed stress measurement die was mounted to the QFN package. The chips were encapsulated with Hysol EO1080 thermosetting polymer material. Curing was performed using an open-ended microwave oven system equipped with in situ temperature control. Three different temperature profiles for microwave curing were selected according to the requested degree of cure and chemical composition of the cured material. A convection cure profile was selected for the control group samples. Temperature cycle tests and highly accelerated stress tests (HAST) were performed on a total number of 80 chips. Ninety-five QFN packages with stress measurement chips were also manufactured. The increased lifetime expectancy of the microwave-cured packaged chips was experimentally demonstrated and measured between the 62% and 149% increased lifetime expectancies after temperature cycle test (TCT), and between 63% and 331% after a HAST and TCT compared to conventionally cured packages. The analysis of specifically designed stress test chips showed significantly lower residual stresses ranging from 26 to 58.3 MPa within the microwave-cured packages compared to conventionally cured packaged chips, which displayed residual stresses ranging from 54 to 80.5 MPa. Therefore, this paper provides additional confidence in the industrial relevance of the microwave curing system and its advantages compared to the traditional convection oven systems.

상업용 대형 가스오븐 시스템의 최적 설계

본 연구는 국내 상업용 대형 가스오븐 시스템 개발을 목표로 연소기의 연소조건에 대한 수치해석 및 실험을 통해 적정 당량비를 결정한 후 공급열량(20,000 kcal)에 적합한 열교환기를 설계하고 대류 팬 제어방법을 검토하여 상업용 대형 가스오븐 시스템 설계 및 최적운전조건을 도출하는 것이다. 실험결과 당량비는 0.82가 가장 적절하였고 오븐 내부 중앙지점의 온도가 <TEX>$200^{\circ}C$</TEX>까지 도달하는데 걸리는 시간은 대류 팬의 회전방향이 반시계방향일 때 시계방향 보다 단축되었다. 또한 오븐 내부의 온도를 균일하게 유지하기 위해서는 대류 팬 제동장치가 필요하였다. 오븐 내부의 승온구간과 온도유지구간 동안 배출되는 배기가스의 열량을 통해 시스템 효율을 비교한 결과 전열면적이 큰 열교환기를 설치한 시스템의 효율이 높게 나타났다. This research was conducted for the optimal design of large commercial gas oven system. Equivalent ratio was determined through a numerical analysis and experiments on the combustion condition of the combustor. After reviewing the supply capacity of burner(20,000 kcal) and control method of convection fan, two types of heat exchangers designed. In order to maintain a uniform temperature inside the oven is required convection fan braking system. The center temperature in the oven rises more rapidly when the convectional fan is rotated in the counterclockwise direction than the counter-clockwise direction. And The efficiency of the system by installing a large heat transfer area was higher.

English

Microwave oven system is an indispensable electric appliance in modern kitchen that heats, bakes or cooks the food by exposing it with electromagnetic radiation. This paper discusses the application potential for development of electric oven systems for enhanced functionality and more user friendliness.

Gold Ball Wire Bonding with Heated Tool for Automotive Microelectronics

Microelectronics used in automotive applications have grown considerably in the last few years with more high tech electronics controlling more functions in automobiles. In an effort to have more precise control and to reduce vehicle weight manufacturers are integrating more functions into smaller packages. Many of these packages are embedded in molded plastic. This causes challenges when it comes to wirebonding these devices. They often cannot be heated to traditional Gold Ball Thermosonic wirebonding temperatures of 120 – 150C. However, using a heated capillary to bond the parts which remain at room temperature simplifies the process considerably. Alternatives such as pre-heating the parts in an oven and complex hot gas handler systems are not required. With a resistive wire coil heater surrounding a standard (or long capillary for deep access) sufficient heat can be provided to the wire bond site for a strong and reliable interconnect. The bonding surface can be any material used in gold ball bonding: aluminum bond pads on die, plated contacts, ceramic substrates or plated copper traces on PCBs. This paper will show that this heated tool process has been successfully utilized with 1mil Au wire and many of the standard die and substrate materials with little impact on process parameters.

Investigation of the validity of the kinetic plot method to predict the performance of coupled column systems operated at very high pressures under different thermal conditions

The present study investigates how strong the kinetic plot method is influenced by the changes in plate height, retention factor and apparent column permeability that arise under conditions of very high pressure. More precisely, the study investigates how well a set of performance measurements conducted on a single short column can be used to predict the performance of a long sequence of coupled columns. This has been investigated for the two practically most relevant thermal conditions, i.e., that of a forced-air oven and that of a still-air oven. Measuring column performance data for acetophenone and benzene on a series of coupled 3.5 μm columns that could be operated up to 1000 bar, it was found that the kinetic plot method provides accurate predictions of time versus efficiency for the still-air oven systems, over the entire range of investigated pressures and column lengths (up to 60 cm), provided k′ and K v0 are evaluated at the maximal pressure. For the forced-air oven which leads to worse performances than the still-air oven, the kinetic plot prediction is less accurate, partly because the thermal conditions (near-isothermal) tend to vary if the number of coupled columns increases. The fact that the thermal conditions of the column wall might vary with the column length is an additional complexity making very-high pressure separations less predictable and harder to interpret and model.

Development of an extended path length supersonic slit source for the study of highly corrosive environments

An extended slit nozzle source, whose dimensions exceed previous designs by more than an order of magnitude and which maintains its structural integrity at temperatures in excess of 1100 K, has been designed to create an extended path length zone for the study of the interaction-reaction of corrosive reactants at high concentration. We facilitate the interaction of an increased number density of reactants when an expanding sodium flux (Nax≥1021/cm2 s) sheath formed from the slit nozzle is intersected by comparable halogen atom fluxes. The construction of the large scale dual oven systems necessary to carry out such experiments using both pure and seeded alkali expansions is outlined with emphasis on the fabrication of the extended slit nozzle source. The operation of this alkali source is considered as it creates a long path length high concentration cooperative environment which might be used to monitor exciplex formation, to develop a visible chemical laser oscillator, or to study the long range interaction of excited electronic states. The optical train necessary to probe this high temperature corrosive environment is also outlined.

968. Oven, flo-coating and appropriate handling systems: E R Meyers,Proc Soc Vac Coaters Conf, 23–24 February 1965, Society of Vacuum Coaters, POB 3095, Cleveland 17, Ohio

968. Oven, flo-coating and appropriate handling systems: E R Meyers,Proc Soc Vac Coaters Conf, 23–24 February 1965, Society of Vacuum Coaters, POB 3095, Cleveland 17, Ohio