scholarly journals Nonlinearity Analysis and Compensation of Measuring the Moisture Content of Green Sand Based on Capacitance Method

2012 ◽  
Author(s):  
SHI Dequan ◽  
GAO Guili
Keyword(s):  
Moisture Content ◽  
Green Sand ◽  
Capacitance Method

Nonlinear Rectification for Capacitance Method Measuring the Moisture of Green Sand Based on Functional Link Neural Network

2013 ◽  
Vol 380-384 ◽  
pp. 806-810
Author(s):  
De Quan Shi ◽  
Gui Li Gao ◽  
Jing Wei Dong ◽  
Li Hua Wang
Keyword(s):  
Neural Network ◽  
Moisture Content ◽  
Least Square Method ◽  
Least Square ◽  
Green Sand ◽  
Functional Link ◽  
Moisture Sensor ◽  
Single Output ◽  
Capacitance Method ◽  
Functional Link Neural Network

In order to solve the nonlinear output/input problem of the capacitance method measuring the moisture content of green sand, a nonlinear compensation is added into the measurement system and the neural network is used for nonlinear rectification. Based on introducing the principle of non-linear compensation, a functional link artificial network with multi-input and single-output is constructed. In the network, the output voltage of capacitance moisture sensor is taken as the input and the moisture content of green sand is taken as the output. The data samples obtained in laboratory are used to train the network, and the dynamic rectification model is got. The experimental results show that the maximum difference and relative error of the moisture content are ±0.09% and ±1.85% after nonlinear rectification by the functional link neural network, and it is significantly better than those of the least square method.

Testing for Green Compression Strength and Permeability Properties on the Tailing Sand Samples Gathered from Ex Tin Mines in Perak State, Malaysia

2012 ◽  
Vol 445 ◽  
pp. 859-864 ◽  
Author(s):  
A. Abdullah ◽  
Shamsuddin Sulaiman ◽  
B.T. Hang Tuah Baharudin ◽  
Mohd Khairol Anuar Ariffin ◽  
T.R. Vijayaram ◽  
...  
Keyword(s):  
Moisture Content ◽  
Compression Strength ◽  
Research Work ◽  
Vital Role ◽  
Sand Casting ◽  
Green Sand ◽  
Molding Sand ◽  
Testing Procedures ◽  
Work Samples ◽  
Optimum Working

Permeability and green compression strength are among the important mechanical properties and considered much in the sand casting mould preparation. These molding sand properties play a vital role in determining the optimum moisture content for making green sand casting mould. Tailing sand is the residue mineral from tin extraction, which contains between 94% and 99.5% silica and in abundance in Kinta Valley of state of Perak, Malaysia. In this research work, samples of tailing sands were gathered from four identified ex tin mines located at the Perak State, Malaysia. They were investigated by the standards and testing procedures prescribed by the American Foundrymen Society (AFS). Sand specimens of size Ø50 mm×50 mm in height from various sandwater ratios bonded with 4% clay were compacted on applying three ramming blows of 6666 g each by using a Ridsdale-Dietert metric standard rammer. The specimens were tested for green compression strength using Ridsdale-Dietert universal sand strength machine and permeability number with Ridsdale-Dietert permeability meter. Before the tests were conducted, the moisture content was measured using moisture analyzer. Samples with moisture content ranging from 3 to 3.5% were found to have optimum working range with effective green compression strength and permeability.

Analysis of Interfacial Heat Transfer Coefficient of Green Sand Mold Casting for Aluminum and Tin-Lead Alloys by Using a Lump Capacitance Method

2006 ◽  
Vol 129 (4) ◽  
pp. 595-600 ◽  
Author(s):  
Hsien-Chi Sun ◽  
Long-Sun Chao
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Casting Process ◽  
Sand Mold ◽  
Interfacial Heat Transfer Coefficient ◽  
Interfacial Heat Transfer ◽  
Green Sand ◽  
Air Gaps ◽  
Capacitance Method

During the casting process of green sand mold, air gaps will form between the metal and sand mold. The air gaps will make it difficult to analyze the heat transfer at the mold/metal interface. Generally, an interfacial heat transfer coefficient is employed to evaluate the heat flux transferred across the air gaps. Though the interfacial heat transfer coefficient is highly important, its value is not easily obtained by using the direct experimental or theoretical method. With temperature-measured data, some inverse methods can be used to predict the coefficient. However, the latent heat released and undercooling during the solidification of the molten metal and the moisture of the green sand mold complicate the associated temperature calculations. To overcome this difficulty, a lump capacitance method is proposed in this study to calculate the interfacial heat transfer coefficient for the casting process in green sand mold. Thermalcouples are utilized to measure the temperatures of sand mold and metal. The geometry of casting is cylindrical and the castings are A356 alloy and Sn-20 wt. % Pb alloy. With the predicted interfacial coefficients, the temperature field of the metal was solved numerically. Based on the solidification time, the numerical results are in good agreement with the experimental ones. This verified the feasibility of the proposed method and it can be applied in the future study or design of a casting process.

Identification of the Root Causes for Blowhole Defect in Castings Using Quantitative Risk Ishikawa Diagrams

2021 ◽  
pp. 1-26
Author(s):  
B. Chokkalingam ◽  
M. Priya ◽  
R. Immanual ◽  
B. Varun
Keyword(s):  
Moisture Content ◽  
Rejection Rate ◽  
Primary Objective ◽  
Risk Scores ◽  
Global Risk ◽  
Green Sand ◽  
Iron Transfer ◽  
Moulding Process ◽  
Root Cause ◽  
Major Defect

The primary objective of this work is to reduce blowhole defect occurring in a cast iron transfer box. The transfer box moulds were produced using green sand moulding process, and cores were made using CO2 process. It was found that the transfer box had a rejection rate as high as 60%, and it was mainly due to a blowhole on the top surface of the casting. The Ishikawa and risk Ishikawa diagrams were used to analyze this major defect. The risk Ishikawa diagram was constructed by assigning weights to the major and sub-causes due to which the defect occurs. Further, the probability of risk and its impact values were employed to compute risk scores for the main causes and also global risk. From the work carried out, it was found that that the moulds and the sands along with melting and pouring parameters were the major causes for this defect while damp chill, pouring delays and high moisture content in sand were identified as the root causes for the blowhole defect. The main root cause for the blowhole defect was pouring delay that eventually causes dampness in the chill pieces kept inside the moulds. The remedial measures of keeping the moisture content of the sand within 3.5% and pouring the moulds in the shift II within half an hour after closing them were implemented to eliminate it.

scholarly journals Effect of Moisture Content of Green Sand on The Casting Defects

2020 ◽  
Vol 2 (1) ◽  
pp. 1-6
Author(s):  
Nanang Qosim ◽  
AM Mufarrih ◽  
Ali Sai’in ◽  
A. Hanif Firdaus ◽  
Fina Andika F. A. ◽  
...  
Keyword(s):  
Moisture Content ◽  
Shrinkage Cavity ◽  
Casting Defects ◽  
Green Sand ◽  
Porosity Defects ◽  
Qualitative Observation ◽  
Effect Of Moisture ◽  
Shrinkage Cavities ◽  
Almost All

In this study, three percentages of moisture content on the green sand were benchmarked to be observed their effects on the casting defects. The metal used is scrap Al-Si with wt% of Al 59.7. The metal was melted in a furnace at 550 ºC then poured into sand molds and cooled for 24 hours before it can be removed, cleaned, and finished. There were prepared three specimens for each benchmark. Qualitative observation of defects was done by physical observations on the surface of the specimens. The observations show that on the moisture content of 2.5%, there is a defect in the form of porosity. Defects in the form of drops, misruns, blowholes, and shrinkage cavity are found on the benchmark 3.5%. The most severe defects are found on the benchmark 4.5% in the form of buckles and severe shrinkage cavities that are found in almost all specimens.

scholarly journals Comparison of the Capacitance Method and the Microwave Impulse Method for Determination of Moisture Profiles in Building Materials

10.14311/670 ◽  
2005 ◽  
Vol 45 (1) ◽  
Author(s):  
P. Tesárek ◽  
J. Pavlík ◽  
R. Černý
Keyword(s):  
Moisture Content ◽  
Building Materials ◽  
Basic Principles ◽  
Porous Building Materials ◽  
Calibration Process ◽  
Impulse Method ◽  
Measuring Methods ◽  
Capacitance Method ◽  
Moisture Profiles

A comparison of the capacitance method and the microwave impulse method for the determination of moisture profiles in three typical porous building materials is presented in this paper. The basic principles of the measuring methods are given. The calibration process is described in detail. On the basis of the measured results, it can be concluded that the capacitance method provides better accuracy in the range of lower moisture content than to the microwave impulse method, which is more accurate for the highest values of moisture content. 

Effect of binder and moisture content on compactibility and shear strength of river bed green sand mould

2020 ◽  
Author(s):  
Jatin Sadarang ◽  
Ramesh Kumar Nayak ◽  
Isham Panigrahi
Keyword(s):  
Shear Strength ◽  
Moisture Content ◽  
Green Sand ◽  
River Bed ◽  
Sand Mould

scholarly journals Mechanical Properties of Tin Tailing Sand-Clay Mixture from Batu Gajah, Perak, Malaysia for Making Greensand Casting Mould

2013 ◽  
Vol 773-774 ◽  
pp. 211-217 ◽  
Author(s):  
Azhar Abdullah ◽  
S. Sulaiman ◽  
B.T.H.T. Baharudin ◽  
M.K.A. Ariffin ◽  
N. Haliza
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Moisture Content ◽  
Compression Strength ◽  
Vital Role ◽  
Sand Casting ◽  
Green Sand ◽  
Test Pieces ◽  
Average Grain Size ◽  
Cylindrical Test

Tailing sand from ex-tin mine in Batu Gajah containing between 95.9 to 98.9% silica. In this research involved the process of, conducting the mechanical sieve grading to identify the size spread, plotting the grain size distribution and calculating the average grain size. Further on with the effects of controlled additions of clay (bentonite) and water and determining the working range on the mechanical properties. The investigation involved comparing the mechanical properties of the tailing sand to the requirement for foundry sand applications listed by Foseco Ferrous Foundrymans Handbook (Foseco). Permeability and green compression strength are the important mechanical properties and considered much in the sand casting mould preparation. These mechanical properties play a vital role in determining the allowable clay and moisture content for working range of tailing sand for making green sand casting mould. Experiments for this investigation were conducted according to American Foundrymen Society (AFS) standard of procedures. Cylindrical test pieces dimensioning of Ø50 mm×50 mm in height from various sandwater ratios bonded with 3.8%wt clay and then 7.4%wt clay, were compacted by applying three ramming blows of 6666 g each using Ridsdale-Dietert metric standard rammer. The specimens were tested for green compression strength using Ridsdale-Dietert universal sand strength machine and permeability number with Ridsdale-Dietert permeability meter. Before the tests were conducted, the moisture content was measured using moisture analyser. Tailing sand with allowable moisture content ranging from 3 to 3.5% (bonded with 3.8%wt clay) and 5.5 to 6% (bonded with 7.4%wt clay) were found to have optimum working range with effective green compression strength and permeability.

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