scholarly journals Improvement of a scraper heat exchanger for pre-heating plant-based raw materials before concentration

2020 ◽  
Vol 3 (11 (105)) ◽  
pp. 6-12
Author(s):  
Kateryna Kasabova ◽  
Sergei Sabadash ◽  
Valentyna Mohutova ◽  
Vadym Volokh ◽  
Anatolii Poliakov ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Raw Materials ◽  
Heating Plant

Temperature Transients in a Triple Heat Exchanger

1984 ◽  
Vol 198 (3) ◽  
pp. 145-154
Author(s):  
P C Chiu ◽  
E H K Fung
Keyword(s):  
Heat Exchanger ◽  
Nuclear Reactor ◽  
Reactor Power ◽  
Solar Heating ◽  
Inlet Temperature ◽  
Exchange Processes ◽  
Flow Experiments ◽  
Heating Plant ◽  
Reactor Power Plant ◽  
Secondary Fluid

A triple heat exchanger, so called because there are three heat exchange processes taking place in it, was built to simulate the system behaviour of a nuclear reactor power plant or a solar heating plant which is characterized by the two circulating loops of the fluid flow. Experiments were carried out to study the temperature transients under disturbances in secondary fluid inlet temperature and power output from immersion heaters. Numerical results were obtained from the weighted residual formulation of the proposed dynamic model and they were shown to be in general agreement with the two sets of experimental responses.

scholarly journals Optimization of Scraped Surface Heat Exchanger Process Parameters for Manufacture of Bottle Gourd Halwa

2019 ◽  
Author(s):  
Suresh Velpula ◽  
Bhadania AG ◽  
Pinto SV ◽  
Aravind T ◽  
Umapathy KS
Keyword(s):  
Heat Exchanger ◽  
Process Parameters ◽  
Raw Materials ◽  
Operating Cost ◽  
Surface Heat ◽  
Bottle Gourd ◽  
Sensory Characteristics ◽  
Batch Size ◽  
Scraped Surface Heat Exchanger ◽  
Surface Heat Exchanger

The present investigation has been aimed to study the effect of various process parameters of scraped surface heat exchanger (SSHE) on the sensory characteristics of fresh bottle gourd halwa. The horizontal SSHE designed and fabricated at the Institute was used to manufacture bottle gourd halwa. The freshly prepared bottle gourd halwa samples were analyzed for their sensory characteristics prepared at different scraper speed (R1, R2, R3 at 20, 30 and 40 rpm respectively), and operating steam pressure (G1, G2, G3 at 0.75, 1.0 and 1.5 kg/cm2 respectively) for varying batch size (B1, B2, B3 of 2, 3 and 4 kg respectively). A uniform quality product with respect to flavor, body and texture, color and appearance, and overall acceptability (sensory scoring) was obtained employing the combination of treatments G2B3S2 among the rest of combinations. Cost analysis of bottle gourd halwa prepared in SSHE under operating condition G2B3S2 was computed at `150.35; the raw materials cost and operating cost was `116.82 and `33.53, respectively.

Exergy and Thermoeconomic Analysis of a Solar Air Heating Plant

2014 ◽  
Author(s):  
Miguel A. Lozano ◽  
Carla Mancini ◽  
Luis M. Serra ◽  
Vittorio Verda
Keyword(s):  
Heat Exchanger ◽  
Solar Energy ◽  
Ambient Air ◽  
Solar Heating ◽  
Thermodynamic Efficiency ◽  
Water Tank ◽  
Water Storage Tank ◽  
Air Heating ◽  
Productive Structure ◽  
Heating Plant

The aim of this work is to present the energy, exergy and thermoeconomic analysis of a hypothetical solar air heating plant located in Zaragoza, Spain. The plant consists mainly of four parts: 1) a field of solar collectors, 2) a water tank storage, 3) a heat exchanger where heat energy is transferred from the collectors to the water storage tank, and 4) a water to air heater heat exchanger. Circulating pumps, pipes and fan have also been considered. In a previous work of the authors the design variables of the system were optimally determined from a conventional economic approach. In this paper, a productive structure for the plant has been proposed and energy losses and exergy destructions (or irreversibility) have been calculated. Energy and exergy efficiencies have also been determined for each of the components and the whole system. Moreover, the costs of internal flows have been dynamically calculated for the time period under consideration. The very specific features of solar heating systems: thermal energy storage as well as continuous variation of solar radiation and energy demand (seasonal and throughout the day) impose important difficulties, which in our opinion have not been deeply studied yet in current methodologies. The major conclusions are: i) energy, exergy and thermoeconomic analyses following a dynamic approach is very sensitive to the reference environment (ambient air temperature), ii) the same productive structure can and must be used for all of them, iii) solar energy should be considered as a high quality source and thermodynamic efficiency of solar heating plants is very low (2.5% in our case), and iv) a dynamic analysis of the process of cost formation through the different components reveals interesting and valuable information about the physics and economics of solar energy conversion systems.

scholarly journals The Construction of Oven Designed by Heat Exchanger in Drying Porang at SME Coco Prima

2019 ◽  
Vol 4 (2) ◽  
pp. 119-124
Author(s):  
Kerista Sebayang ◽  
Herli Ginting ◽  
Andriayani Andriayani ◽  
Agus Salim Harahap
Keyword(s):  
Heat Exchanger ◽  
Water Vapour ◽  
Raw Materials ◽  
Weather Conditions ◽  
Raw Material ◽  
Liquid Petroleum Gas ◽  
Medium Enterprise ◽  
Lower Temperature ◽  
Heat Exchanges ◽  
Reheating Process

The small-medium enterprise (SME) Coco Prima has been under nurtured of LPPM USU since 2018. Ever since, it has been improving its productivity and diversifying its productivity into drying products. Currently, this SME manages porang as one of new export commodity. The problem faced by partners is a large and fast drying methodology. Porang or iles-iles are rotten raw materials that only last for three days after harvesting due to the unpleasant odors resulted more than three days, and subsequently, they cannot be processed. Drying under sunlight requires to four days reaching about 70% degree of dryness. Due to unfavorable weather conditions, the raw material becomes sweaty and moldy and produces black colour and soft textures. Therefore, a 3x3x2 cubic meter of drying oven has been constructed along with shelves and heat exchanges supported by liquid petroleum gas (LPG) gas. The heat exchange is designed accordingly to provide lower temperature in the oven, so that the air pressure within it is more efficient and less heat is wasted during reheating process. The heating is sufficient by using LPG and fan 18’. The oven is consisted of two layers in which between the layers are given glass wool as a heat barrier to the environment. It is also designed with a small vent exactly on the middle of the top with the intention to flow water vapour out from the vent, while the cold air is touched by that water vapour in the oven, it converts downward on the heat exchanger repeatedly. From this applied system, 750 kg iles-iles was heated within two days with a tube-of-12 kg LPG gas.

Lightweight Mortar Containing High Amounts of Alternative Raw Materials with Increased Thermal Resistance

2018 ◽  
Vol 916 ◽  
pp. 190-194
Author(s):  
Tomáš Melichar ◽  
Jiří Bydžovský ◽  
Ámos Dufka
Keyword(s):  
Fly Ash ◽  
Raw Materials ◽  
Lightweight Aggregate ◽  
Strength Properties ◽  
Physical Chemical ◽  
Chemical Phase ◽  
Alternative Materials ◽  
The Matrix ◽  
Lightweight Mortar ◽  
Heating Plant

The paper researches lightweight mortars based on a high content of alternative materials. 25 – 30% heating plant slag was used in order to modify the matrix. Fly ash agloporite (a lightweight aggregate produced by self-combustion from fly ash) was used as an aggregate. Mortars were exposed to the temperatures up to 1,250° C. Two types of cooling were carried out at 1,000° C; controlled slow (in the furnace) and by shock (in water baths of approximate 18° C). Developed materials were further analyzed by various methods: monitoring changes in an observation furnace, physical–mechanical (to determine strength properties), physical-chemical (phase composition - XRD) and microstructural (SEM).

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

Microstructural characterization of laser-melted/roller-quenched dicalcium silicate

1988 ◽  
Vol 46 ◽  
pp. 582-583
Author(s):  
C. J. Chan ◽  
K. R. Venkatachari ◽  
W. M. Kriven ◽  
J. F. Young
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Shape Change ◽  
Microstructural Characterization ◽  
Particle Size Effect ◽  
Dicalcium Silicate ◽  
Laser Melting ◽  
Uniform Size ◽  
Cell Shape Change ◽  
Wide Range

Dicalcium silicate (Ca2SiO4) is a major component of Portland cement. It has also been investigated as a potential transformation toughener alternative to zirconia. It has five polymorphs: α, α'H, α'L, β and γ. Of interest is the β-to-γ transformation on cooling at about 490°C. This transformation, accompanied by a 12% volume increase and a 4.6° unit cell shape change, is analogous to the tetragonal-to-monoclinic transformation in zirconia. Due to the processing methods used, previous studies into the particle size effect were limited by a wide range of particle size distribution. In an attempt to obtain a more uniform size, a fast quench rate involving a laser-melting/roller-quenching technique was investigated.The laser-melting/roller-quenching experiment used precompacted bars of stoichiometric γ-Ca2SiO4 powder, which were synthesized from AR grade CaCO3 and SiO2xH2O. The raw materials were mixed by conventional ceramic processing techniques, and sintered at 1450°C. The dusted γ-Ca2SiO4 powder was uniaxially pressed into 0.4 cm x 0.4 cm x 4 cm bars under 34 MPa and cold isostatically pressed under 172 MPa. The γ-Ca2SiO4 bars were melted by a 10 KW-CO2 laser.

Crystallization of barium hexaferrite

1992 ◽  
Vol 50 (1) ◽  
pp. 362-363
Author(s):  
Chung-kook Lee ◽  
Yolande Berta ◽  
Robert F. Speyer
Keyword(s):  
Size Distribution ◽  
Raw Materials ◽  
Barium Hexaferrite ◽  
Recording Media ◽  
Magnetic Recording Media ◽  
Promising Candidate ◽  
Crystallization Method ◽  
Temperature Heat ◽  
High Density Magnetic Recording ◽  
Temperature Heat Treatment

Barium hexaferrite (BaFe12O19) is a promising candidate for high density magnetic recording media due to its superior magnetic properties. For particulate recording media, nano-sized single crystalline powders with a narrow size distribution are a primary application requirement. The glass-crystallization method is preferred because of the controllability of crystallization kinetics, hence, particle size and size distribution. A disadvantage of this method is the need to melt raw materials at high temperatures with non-reactive crucibles, e.g. platinum. However, in this work, we have shown that crystal growth of barium hexaferrite occurred during low temperature heat treatment of raw batches.

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