Selective heating and enhanced boiling in microwave heating of multicomponent (solid–liquid) foods

2019 ◽  
Vol 43 (2) ◽  
Author(s):  
Tushar Gulati ◽  
Ashim K. Datta ◽  
Mohsen Ranjbaran
2017 ◽  
Vol 6 (1) ◽  
Author(s):  
Xuefeng Liao ◽  
Guo Chen ◽  
Qianqian Liu ◽  
Jin Chen ◽  
Jinhui Peng

AbstractIn the present study, the moisture of high titanium slag was chosen as the research object. Taking advantage of selective heating of microwave and the specific inductive capacity of water, the drying experiment of high titanium slag using microwave heating have been carried out. The results revealed that the presence of moisture in the form of high titanium slag was adsorbed water, and the wet sample possesses excellent wave-adsorbing performance; the bed depth preferred was no larger than 10 mm, with moisture content at around 3%. The microwave drying process was divided into two stages: the constant-stage and the deceleration-stage. The optimum conditions were identified to be microwave power of 700 W, sample mass of 200 g, bed depth of 10 mm and drying time of 50 s. The dehydration extent can reach 90% and moisture content remains at 0.3% under the optimum conditions. The demonstration of microwave drying techniques can be applied effectively and efficiently into the treatment processing of drying of the raw materials of metallurgy and chemical industry with the theoretical and scientific basis.


2014 ◽  
Vol 88 ◽  
pp. 21-30
Author(s):  
Noboru Yoshikawa

Microwave heating was discovered more than 60 years ago. And nowadays, it became popular for the use as domestic ovens. Microwave has also been utilized for the industrial processes, such as drying and roasting. On the other hand, there have been many applications of microwave, being investigated for materials' processing and environmental technologies. They are attempted to take advantage of some specific characteristics in microwave heating, which differs from that of the conventional one. Rapid heating, internal heating, selective heating are the features to be taken into consideration. Moreover, so-called "non-thermal effect" is the additional feature in which researchers are particularly interested. In this article, it is intended to describe fundamental aspects in microwave heating and introduce some selected topics of research projects performed in our research group. They include researches on fabrication of some functional materials and on handling industrial wastes etc. In this article, it is also intended to interpret the phenomena observed in these applications from the fundamental view points of electromagnetic wave interaction with materials.


Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1922
Author(s):  
Aiyuan Ma ◽  
Xuemei Zheng ◽  
Lei Gao ◽  
Kangqiang Li ◽  
Mamdouh Omran ◽  
...  

Given the shortage of zinc resource, the low utilisation efficiency of secondary zinc resource, and the crucial problem that the synchronous dissolution of zinc from different mineral phases, an activation pretreatment method merged with calcium activation and microwave heating approach was proposed to enhance the zinc leaching from complex encapsulated zinc-containing metallurgical residues (ZMR). Results indicated that under the optimal pretreatment conditions, including microwave activation temperature of 400 °C, CaO addition of 25% and activation time of 20 min, the zinc leaching rate reached 91.67%, which was 3.9% higher than that by conventional roasting pretreatment. Meanwhile, microwave heating presents excellent treatment effects, manifested by the zinc leaching rates, all exceeding that of conventional roasting under the same conditions, while the process temperature is decreased by 200 °C. In addition, XRD and SEM-EDS analysis denoted that microwave calcification pretreatment can effectively promote the transformation of the refractory zinc minerals like Zn2SiO4 and ZnFe2O4 into the easily leachable zinc oxides. The distinctive selective heating characteristics of microwave heating strengthened the dissociation of mineral inclusion, and the generated cracks increased the interfacial reaction area and further enhancing the leaching reaction of zinc from ZMR.


RSC Advances ◽  
2014 ◽  
Vol 4 (31) ◽  
pp. 16172-16180 ◽  
Author(s):  
Kevin Adlington ◽  
Robert McSweeney ◽  
Georgios Dimitrakis ◽  
Samuel W. Kingman ◽  
John P. Robinson ◽  
...  

The formation of a CCTP active catalyst, which is promoted by adopting microwave heating and an “in situ” synthesis methodology.


2014 ◽  
Vol 564 ◽  
pp. 310-314 ◽  
Author(s):  
Mohd Roshdi Hassan ◽  
Babak Ganjeh

Microwave heating technology regarded as a highly time and energy efficient heating technique which recently has acquired attention in aerospace composite manufacturing. Capability of offering exceptional advantages including volumetric and selective heating makes the microwave heating attractive alternative over the conventional highly time and energy consuming autoclave processing. However due to the complexity of interaction mechanism of electromagnetic field and composite materials, applying microwave ovens on an industrial level requires comprehensive experimental and numerical investigation to determine and predict the materials behavior during the curing process. On laboratory scales great potentials of microwave heating in terms of time and energy saving have been proven through several studies, a concise review over these studies is presented in this paper.


1994 ◽  
pp. 707-709
Author(s):  
M. Kyereme ◽  
R. C. Anantheswaran

2014 ◽  
Vol 12 ◽  
pp. 21-28 ◽  
Author(s):  
O. Wiedenmann ◽  
R. Ramakrishnan ◽  
P. Saal ◽  
E. Kılıç ◽  
U. Siart ◽  
...  

Abstract. Microwave induced selective heating outmatches conventional mold heating by convective heat transfer in means of energy efficiency and cycle time. Moreover, it provides the opportunity of a local manipulation of solidification and cooling processes within the sand casting mold. In this paper, we investigate the suitability of different highly absorbing materials to indirectly heat up the mostly microwave transparent sand mold. The temperature-dependent permittivity of the involved materials is determined by resonator experiments and subsequently used to simulate the electromagnetic field and the thermodynamic response of the sand mold prior to a metal casting process. Experimental results are presented and compared with the outcome of the coupled electromagnetic-thermodynamic simulations and the influence of local microwave heating on the solidification and cooling of the cast is studied.


2020 ◽  
Vol 4 (12) ◽  
pp. 5927-5946
Author(s):  
Feiqiang Guo ◽  
Yichen Dong ◽  
Beile Tian ◽  
Shilin Du ◽  
Shuang Liang ◽  
...  

Microwave heating has the potential to promote gas production and tar removal during biomass pyrolysis or gasification based on its advantageous characteristics such as rapid heating and selective heating.


1990 ◽  
Vol 189 ◽  
Author(s):  
Steven J. Oda ◽  
Ibrahim S. Balbaa ◽  
Bruce T. Barber

ABSTRACTThis paper reviews the results from two relatively new microwave heating studies under development at Ontario Hydro's Research Division. The first study involves the development of a hybrid kiln to process advanced ceramics at high temperatures. Using a combination of resistive heating elements and microwave heating, this new device has been operated to show significant process advantages in terms of time and energy savings. A description of the hybrid kiln is presented together with the test results for calcining and sintering a variety of ceramic materials.The second investigation involves the use of microwave heating for the treatment of hazardous wastes. The selective heating ability of microwaves has been applied to reduce the environmental impact of wastes generated from industrial processes. An example is provided to illustrate the advantages and difficulties of applying this technology.


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