scholarly journals Achieving Control of Coating Process in your Foundry

2015 ◽  
Vol 15 (4) ◽  
pp. 110-114 ◽  
Author(s):  
G.L. Di Muoio ◽  
N.S. Tiedje

Abstract Achieving control of coating thickness in foundry moulds is needed in order to guarantee uniform properties of the mould but also to achieve control of drying time. Since drying time of water based coatings is heavily dependent on the amount of water present in the coating layer, a stable coating process is prerequisite for a stable drying process. In this study, we analyse the effect of different variables on the coating layer properties. We start by considering four critical variables identified in a previous study such as sand compaction, coating density, dipping time and gravity and then we add centre points to the original experimental plans to identify possible non-linear effects and variation in process stability. Finally, we investigate the relation between coating penetration (a variable that is relatively simple to measure in production) and other coating layer thickness properties (relevant for the drying process design). Correlations are found and equations are provided. In particular it is found that water thickness can be directly correlated to penetration with a simple linear equation and without the need to account for other variables.

2021 ◽  
Vol 161 ◽  
pp. 105770
Author(s):  
S. Madlmeir ◽  
T. Forgber ◽  
M. Trogrlic ◽  
D. Jajcevic ◽  
A. Kape ◽  
...  

2012 ◽  
Vol 2 (1) ◽  
pp. 14-20
Author(s):  
Yuwana Yuwana

Experiment on catfish drying employing ‘Teko Bersayap’ solar dryer was conducted. The result of the experiment indicated that the dryer was able to increase ambient temperature up to 44% and decrease ambient relative humidity up to 103%. Fish drying process followed equations : KAu = 74,94 e-0,03t for unsplitted fish and KAb = 79,25 e-0,09t for splitted fish, where KAu = moisture content of unsplitted fish (%), KAb = moisture content of splitted fish (%), t = drying time. Drying of unsplitted fish finished in 43.995 hours while drying of split fish completed in 15.29 hours. Splitting the fish increased 2,877 times drying rate.


2019 ◽  
pp. 28-34
Author(s):  
Margarita Castillo-Téllez ◽  
Beatriz Castillo-Téllez ◽  
Juan Carlos Ovando-Sierra ◽  
Luz María Hernández-Cruz

For millennia, humans have used hundreds of medicinal plants to treat diseases. Currently, many species with important characteristics are known to alleviate a wide range of health problems, mainly in rural areas, where the use of these resources is very high, even replacing scientific medicine almost completely. This paper presents the dehydration of medicinal plants that are grown in the State of Campeche through direct and indirect solar technologies in order to evaluate the influence of air flow and temperature on the color of the final product through the L* a* scale. b*, analyzing the activity of water and humidity during the drying process. The experimental results showed that the direct solar dryer with forced convection presents a little significant color change in a drying time of 400 min on average, guaranteeing the null bacterial proliferation and reaching a final humidity between 9 % and 11 %.


Horticulturae ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 40
Author(s):  
Vincenzo Alfeo ◽  
Diego Planeta ◽  
Salvatore Velotto ◽  
Rosa Palmeri ◽  
Aldo Todaro

Solar drying and convective oven drying of cherry tomatoes (Solanum lycopersicum) were compared. The changes in the chemical parameters of tomatoes and principal drying parameters were recorded during the drying process. Drying curves were fitted to several mathematical models, and the effects of air temperature during drying were evaluated by multiple regression analyses, comparing to previously reported models. Models for drying conditions indicated a final water content of 30% (semidry products) and 15% (dry products) was achieved, comparing sun-drying and convective oven drying at three different temperatures. After 26–28 h of sun drying, the tomato tissue had reached a moisture content of 15%. However, less drying time, about 10–11 h, was needed when starting with an initial moisture content of 92%. The tomato tissue had high ORAC and polyphenol content values after convective oven drying at 60 °C. The dried tomato samples had a satisfactory taste, color and antioxidant values.


Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 284
Author(s):  
Ebrahim Taghinezhad ◽  
Mohammad Kaveh ◽  
Antoni Szumny

Drying can prolong the shelf life of a product by reducing microbial activities while facilitating its transportation and storage by decreasing the product weight and volume. The quality factors of the drying process are among the important issues in the drying of food and agricultural products. In this study, the effects of several independent variables such as the temperature of the drying air (50, 60, and 70 °C) and the thickness of the samples (2, 4, and 6 mm) were studied on the response variables including the quality indices (color difference and shrinkage) and drying factors (drying time, effective moisture diffusivity coefficient, specific energy consumption (SEC), energy efficiency and dryer efficiency) of the turnip slices dried by a hybrid convective-infrared (HCIR) dryer. Before drying, the samples were treated by three pretreatments: microwave (360 W for 2.5 min), ultrasonic (at 30 °C for 10 min) and blanching (at 90 °C for 2 min). The statistical analyses of the data and optimization of the drying process were achieved by the response surface method (RSM) and the response variables were predicted by the adaptive neuro-fuzzy inference system (ANFIS) model. The results indicated that an increase in the dryer temperature and a decline in the thickness of the sample can enhance the evaporation rate of the samples which will decrease the drying time (40–20 min), SEC (from 168.98 to 21.57 MJ/kg), color difference (from 50.59 to 15.38) and shrinkage (from 67.84% to 24.28%) while increasing the effective moisture diffusivity coefficient (from 1.007 × 10−9 to 8.11 × 10−9 m2/s), energy efficiency (from 0.89% to 15.23%) and dryer efficiency (from 2.11% to 21.2%). Compared to ultrasonic and blanching, microwave pretreatment increased the energy and drying efficiency; while the variations in the color and shrinkage were the lowest in the ultrasonic pretreatment. The optimal condition involved the temperature of 70 °C and sample thickness of 2 mm with the desirability above 0.89. The ANFIS model also managed to predict the response variables with R2 > 0.96.


2013 ◽  
Vol 724-725 ◽  
pp. 296-299
Author(s):  
Chun Xiang Chen ◽  
Xiao Qian Ma ◽  
Xiao Cong Li ◽  
Wei Ping Qin

To find out an alternative of coal saving, a kind of microalgae, Chlorella vulgaris (C. vulgaris) which is widespread in fresh water was studied by digital blast drying system. The effect of the moisture content, drying thickness and temperature on the drying process of C. vulgaris were investigated. The results indicated that when the drying temperature is high, the moisture content is low and the material thickness is small, the drying time is short. The drying process of C.vulgaris can be divided into two stages, and the mass loss is mainly occurred in the second stage . The results will provide guidance for design of drying process and dryer of microalgae.


2010 ◽  
Vol 65 (21) ◽  
pp. 5716-5727 ◽  
Author(s):  
Sajal M. Patel ◽  
Swetaprovo Chaudhuri ◽  
Michael J. Pikal

2021 ◽  
Vol 1031 ◽  
pp. 67-74
Author(s):  
Alexey V. Ishkov ◽  
Vladimir N. Malikov ◽  
Alexander Shegolev

The paper describes the researches of the SHS process initiation in samples of powder mixtures of reagents intended for steel parts hardening with an excess of Al or B2O3 by a heat source. Mixtures of reagents with different weight ratios of components were used as samples. Thereat, the initiation of SHS process in thin layers was conducted with a coating layer thickness of no more than 6 mm for all tested compositions. The dependences of the combustion rate on various factors including particle size of powder materials and charge composition have been obtained. The main factors influencing the dependences of initiation (ignition) and combustion rate are established, and the degree of influence of these factors on the dependences is estimated. The obtained results made it possible to correct the composition of the base mixture reasonably in order to achieve the required combustion rate.


2015 ◽  
Vol 4 (1) ◽  
pp. 20-24 ◽  
Author(s):  
M. Djaeni ◽  
N. Asiah ◽  
S Suherman ◽  
A. Sutanto ◽  
A. Nurhasanah

Energy usage is crucial aspect on agriculture drying process. This step spends about 70% of total energy in post harvest treatment. The design of efficient dryer with renewable energy source is urgently required due to the limitation of fossil fuel energy. This work discusses the performance of air dehumidification using rice husk fuel as heat source for onion, and paddy drying. Unlike conventional dryer, the humidity of air during the drying was dehumidified by adsorbent. Hence, the driving force of drying can be  kept high.  As consequences, the drying time and energy usage can be reduced. Here, the research was conducted in two step: laboratory and pilot scale tests. Results showed that the lowering air humidity with rice husk fuel has improved the energy efficiency. At operational temperature 60oC, the heat efficiency of 75%  was achieved. 


2021 ◽  
Vol 17 (1) ◽  
pp. 70-77
Author(s):  
E. Е. Ulyanchenko ◽  
N. N. Vinevskaya

Cultivation and use of Virginia 202 broadleaf skeletal variety for the production of smoking tobacco has broad prospects. Problems of post-harvest processing of large leaves with a massive midrib consist in high energy costs with an artificial drying method or the provision of facilities for long-term natural drying. The aim of the research is to apply physical method of cutting the leaf midrib to intensify drying and to determine the effect of this technique on the quality indicators of raw materials. It has been found that the technique of cutting the midrib on the Virginia 202 variety contributes to a significant optimization of the drying process without reducing the quality of raw materials. The drying time of leaves with the combined method is reduced by 2,8 times, with the natural method – by 2,3 times, and the quality indicators of raw materials improve. Commercial quality is characterized by the yield of 1 commercial grade, for combined drying the yield of 1 grade has increased in comparison with the control sample by 27% and amounted to 86,5%, with natural drying – the increase in yield is 4%. Cutting the midrib increases the fiber yield by 3–5% and contributes to an increase in the volumetric-elastic properties of the fiber, providing an economical consumption of raw materials for the production of smoking articles, the consumption is 676,8–753,8 g/1000 pcs. The gustatory quality improves, raw materials with a cut midrib have optimal values of the ratio of carbohydrate-protein balance in the range of 1,08–1,5, the strength is preserved due to the lower consumption of nicotine during the shorter drying period, in comparison with drying the leaf without cutting the midrib. Cutting the midrib in Virginia 202 is cost effective.


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