Numerical Investigation of New Cooling Method for Clinker Flow in Opposite Direction with Airflow at Different Height Ratios

2021 ◽  
Vol 895 ◽  
pp. 157-176
Author(s):  
Nasr A. Jabbar ◽  
Ali Amer Alshammary ◽  
Ihsan Y. Hussain ◽  
Luay S. Alansari

Several parameters affect the properties of Portland cement and one of these parameters is the cooling rate of the clinker. If the effectiveness of the cooling method of the clinker increases, a good enhancement in the properties of Portland cement will be found. Depending on the new cooling method suggestion by Nasr et. al. [20], the counter pattern of air clinker flow was studied using (FLUENT 6.3.26). The dimensions of the cooling room in grate cooler, the constant mass flow rate of both clinker and air, different height ratios, and different clinker porosity were considered in this numerical work. The results show that the heat transfers in the first half of the cooling room (0 < X < 0.9 m) is larger than that in the second half (0.9 < X < 1.8 m), and this leads to an increase in the temperature of outlet air so can benefits from it in the heating of furnace. When the clinker and air are flowing in the counter direction, the cooling method is more beneficial when compared with that of parallel flow because the exiting clinker has a great rate of cooler and the air exits from the grate cooler is loaded with large thermal energy. Finally, it can design the best length of gate according to the required clinker temperature at the outlet side, and this results to reduce the cost of the cooling process according to the temperature distribution results at (0 < X > 1.8m) for different porosity and H.R values.

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1622
Author(s):  
Wipawee Tepnatim ◽  
Witchuda Daud ◽  
Pitiya Kamonpatana

The microwave oven has become a standard appliance to reheat or cook meals in households and convenience stores. However, the main problem of microwave heating is the non-uniform temperature distribution, which may affect food quality and health safety. A three-dimensional mathematical model was developed to simulate the temperature distribution of four ready-to-eat sausages in a plastic package in a stationary versus a rotating microwave oven, and the model was validated experimentally. COMSOL software was applied to predict sausage temperatures at different orientations for the stationary microwave model, whereas COMSOL and COMSOL in combination with MATLAB software were used for a rotating microwave model. A sausage orientation at 135° with the waveguide was similar to that using the rotating microwave model regarding uniform thermal and electric field distributions. Both rotating models provided good agreement between the predicted and actual values and had greater precision than the stationary model. In addition, the computational time using COMSOL in combination with MATLAB was reduced by 60% compared to COMSOL alone. Consequently, the models could assist food producers and associations in designing packaging materials to prevent leakage of the packaging compound, developing new products and applications to improve product heating uniformity, and reducing the cost and time of the research and development stage.


1980 ◽  
Vol 7 (2) ◽  
pp. 256-263 ◽  
Author(s):  
M. A. Ward ◽  
S. M. Khalil ◽  
B. W. Langan

As the cost of energy and hence the cost of producing Portland cement increase, the question arises as to whether we are obtaining optimum performance from the admixtures we use. As an example, data are presented indicating that a significant improvement in strength and shrinkage can be achieved by optimizing the sulfate content of the cement for given cement–admixture combinations. It is shown that the optimum SO3 is clearly a function of the initial temperature of the concrete, particularly during the first 24 h after casting, a characteristic of considerable importance in hot weather concreting and steam curing of concrete products. It is recommended that more attention be directed towards optimizing the effectiveness of chemical admixtures in both the ready-mixed concrete and precast concrete industries.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tawfeeq Abdullah Alkanhal

Purpose This paper aims to disperse the silicon dioxide in water (as the mono nanofluid [MN]) and then, carbon nanotube (CNT)-silica composite in water (as the hybrid nanofluid [HN]). Design/methodology/approach Nanofluids have gained lots of attention through the recent years. Due to their usage in the industries and also medical applications, they have high protentional to be studied in different aspects. The most common study for the nanofluids is to understand the heat transfer capacity for each material in each fluid. These material(s) or fluid(s) can be one (mono nanofluid) or more than one (hybrid nanofluid). Findings The mixture of two solids is to assess the unique properties of each material and also to decrease the cost of experiments. The heat transfers for both MN and HN were measured at volume fractions up to 1.0%, and temperatures up to 50°C. Also, the heat transfers were compared. By more CNT, thermal conductivity was enhanced about 17.39% (from 12.42% of MN to 29.81% of HN). Originality/value X-Ray diffraction and field emission scanning electron microscope (FESEM) were examined for mono solids and the composite. After the experimental study, for MN and HN, four novel correlations calculated.


2021 ◽  
Vol 1019 ◽  
pp. 205-210
Author(s):  
Deepika S. Singraur ◽  
Bhushan T. Patil ◽  
Vasim A. Shaikh

The cooling process is an essential aspect while designing for uniform heat transfer between the mold and the molded part. Improper design and placement of cooling channels result in non-uniform cooling and thus results in differential shrinkage and warpage on the final product. The installation of the channels yet plays a crucial role in the cooling of the part. Conforming channels that are placed at an optimum distance from the part to enhance the cooling process. In this paper, the performance parameters of straight drilled channels are compared with the conformal cooling channels for an electric alarm box. The analysis indicates that the conformal cooling method improved and enhanced the cooling process and reduced the defects like warpage and differential shrinkage by 25.5% and 28.0% respectively.


2014 ◽  
Vol 900 ◽  
pp. 647-650
Author(s):  
Yu Qing Zheng ◽  
Jing Yu Cui

The temperature distribution of the hot-rolled strip in the ROT cooling process was calculated and analyzed using ABAQUS in this paper. The complicated heat transfer coefficients of hot strip considering the position effects of top and bottom nozzles, and the non-uniform heat transfer situation along the width direction were defined by user subroutine. The simulation results were in good correlation with test results. It’s helpful for further analysis to improve the temperature distribution uniformity and the simulation accuracy for FE model, and guide the on-site production.


2015 ◽  
Vol 639 ◽  
pp. 205-212 ◽  
Author(s):  
Kenichiro Mori ◽  
Tomoyoshi Maeno ◽  
Takuya Suganami

Punching portions of the sheet are sandwiched between the ceramic billets during rapid resistance heating to prevent hardening of these portions. When the heating temperature is locally lower than that of the austenitic transformation, i.e. below 800 oC, this portion is not hardened without occurrence of martensitic transformation, and thus cold punching of hot-stamped parts becomes easy. The ceramic billets are made of alumina and the heat transfers to the billets. The temperature distribution just after resistance heating, the hardness distribution of the hot-stamped sheet, the cold punching load, the quality of the punched hole, etc. were measured. Hardening of punching portions was successfully prevented by sandwiching between the ceramic billets. The cold punching load for the local prevention of hardening was half of that without local prevention and the delayed fracture was also prevented, whereas the drop in hardness around the sheared edge became larger than that for laser cutting.


2010 ◽  
Vol 168-170 ◽  
pp. 1130-1135 ◽  
Author(s):  
Ji Ping Chen ◽  
Jian Qing Qian ◽  
Sheng Zhi Li

A three-dimensional thermo-mechanical coupled model of hot leveling and cooling processes of the steel plate has been conducted with MSC.Superform software. Four kinds of initial temperature distribution patterns have been determined according to literature. The effects of hot leveling and cooling processes on the transversal and longitudinal residual stresses of the steel plate have been analyzed. The results show that the initial temperature distribution patterns have significant influence on the residual stress of the plate. The more uniform temperature distribution patterns along the width of the plate, the smaller residual stress and also the smaller stress fluctuations. The cooling process has greater effect on the residual stress compared with the hot leveling process. The bigger the temperature gradient along the width of steel plate, the larger the residual stress and its fluctuation is. Through the FEM study, the value and direction of transversal and longitudinal residual stresses can be confirmed quantitatively at various positions along the width and length of plate, which can provide guidance to actual measurement of residual stress.


2018 ◽  
Vol 12 (1) ◽  
pp. 167-186 ◽  
Author(s):  
M. Kheradmand ◽  
Z. Abdollahnejad ◽  
F. Pacheco-Torgal

Background:Geopolymeric binders are especially indicated when reusing a wide diversity of wastes. This is an important feature, especially in the European context, in which a circular economy and future zero waste are targeted. Still, the cost of these materials, due to the use of high purity activators, prevents their commercialization as they are simply not competitive enough.Objective:The reduction in the amount of activators could be a cost-efficient solution if the associated decrease in the mechanical properties turned not to be excessive. This means that it is important to investigate the manner in which these additives can be used on their composition in order to compensate that mechanical reduction.Results and Conclusion:This paper discloses results concerning the mixed design of fly ash based geopolymeric mixtures using metakaolin, Portland cement (OPC) and calcium hydroxide as additives. Their influence on the mechanical properties, microstructure and cost-efficiency was studied. The results showed that the use of Portland cement as an additive leads to lower compressive strength. Results also show that geopolymers with different additives have different optimum Na2SiO3/NaOH ratios.


2016 ◽  
Vol 22 (3) ◽  
pp. 111-126
Author(s):  
Zygmimt Lipnicki ◽  
Haima Lechów ◽  
Kataizyna Pantoł

Abstract Ail analytical solution to the equation for cooling of a unit, in the interior of which heat is generated, is presented. For that reason, a simplified non-stationary model for determination of the temperature distribution within the unit, temperature of the contact between unit and a liquid layer, and the evaporating layer thickness in the function of time, is elaborated. A theoretical analysis of the external cooling of the unit, by considering the phenomenon of the liquid evaporation with the use of the Fourier and Poisson’s equations, is given. Both, stationary- and non-stationary description of the cooling are shown. The obtained results of simulation seems to be useful in designing the similar cooling systems. A calculation mode for a cooling systems equipped with the compressor heat pump, as an effective cooling method, is also performed.


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