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Influence of cutting parameters on the performance of plough during hard rock cutting in coal mining

Palaniappan Sathish Kumar, Chinnasamy Moganapriya, Pal Samir Kumar, Rathanasamy Rajasekar

Journal of Sustainable Mining

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2023

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Vol. 22. iss. 3

185--194

EN

Coal ploughs have proved very successful on many faces in various parts of the world. Recently, there has been a general tendency in longwall working to increase the speed at which the machine progresses along the coal face. An increase in production rate demands enhances either due to depth of penetration or cutting speed. This, in turn, results in increasing power demand and also the force acting on an individual pick. To get maximum efficiency from a cutting machine, a number of parameters need to be investigated. The first and foremost thing of interest is naturally the pick geometry. The cutting force can be expected to depend mainly on the rack angle and clearance angle of the tool. The second parameter is the cutting depth, which when enhanced, increases the rate of advancement and, at the same time, results in enhanced cutting force. This results in large power demand and increases wear of picks. Thirdly, cutting speed, in which higher cutting speed will increase the production rate but at the same time is expected to enhance the power demand and the cutting force. This paper aims at investigating the cutting efficiency of the plough by simulating the coal cutting operation in the laboratory. The effect of three main parameters like pick geometry, cutting depth, and cutting speed, on cutting efficiency have been studied in detail. The cutting force elevates at a faster rate with an increase in depth at higher speeds. The percentage increase in force is nearly 20% for a speed increase of 20%.

2

Spinel zinc ferrite nanostructured thin-films for enhanced light-harvesting in polycrystalline solar cells

Shanmugam Arun Kumar, Rathanasamy Rajasekar, Kaliyannan Gobinath Velu, Nagarajan Nithyavathy, Palanisamy Manivasakan

Materials Science Poland

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2021

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Vol. 39, No. 1

24--32

EN

Spinel zinc ferrite (ZnFe2O4) nanocrystallites are applied as an anti-reflection coating (ARC) for the enhanced light harvesting in polycrystalline silicon solar cells (PCSSC) and its effect were studied. Spinel zinc ferrite nanocrystallites were prepared using precursors of zinc and ferric chloride by co-precipitation method. The morphological, optical, electrical characterizations are comprehensively used to establish the performance of spinel ZnFe2O4Nanostructured Thin Films (NTF) covered and uncovered PCSSC. Further, X-ray diffraction and fluorescence analysis have been performed to demonstrate the crystallographic patterns and elemental compositions of ZnFe2O4nanocrystallites. The developed spinel ZnFe2O4NTF on PCSSC shows the reduction in reflectivity (20.3%), improvement in light trapping efficiency (17.5%) and transmittance of the fabricated spinel ZnFe2O4 NTF was validated with optical and electrical observations.

3

Fabrication of a Novel Silver-Based Electrical Contact Composites and Assessment of Its Mechanical and Electrical Properties

Kumar Praveen S., Senthil S. M., Parameshwaran Rathinasamy, Rathanasamy Rajasekar

Archives of Metallurgy and Materials

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2021

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Vol. 66, iss. 4

1087--1094

EN

The electrical contactors play a crucial role in closing the circuit in many power distribution components like overhead lines, underground cables, circuit breakers, transformers, and control systems. The failure in these components mainly occurs due to the break-down of contactors due to the continuous opening and closing action of contacts. Silver (Ag)-based oxide contact materials are widely used in practice, among which silver tin oxide (AgSnO2) is most common. An attempt is made in increasing the performance of AgSnO2, by adding Tungsten Oxide (WO3) in various weight proportions, thus finding the optimal proportion of AgSnO2WO3 to have increased mechanical and electrical performances. All the composite samples are fabricated in-house using powder metallurgy process. The assessment of physical and electrical properties namely, density, hardness, porosity, and electrical conductivity, showed that 90%Ag-8.5%SnO2-1.5%WO3 composite yielded superior results. With help of morphological tests, wear characteristics are also investigated, which showed that 90%Ag-8.5%SnO2-1.5%WO2 composite has a wear coefficient of 0.000227 and a coefficient of friction of 0.174 at an optimized load of 10 N and sliding velocity of 0.5 mm/s.

4

Experimental analysis on the technical behavior of carbon black filled rubber blends’ rollers for rice husk removal application

Paramasivam Prabhakaran, Ranganathan Rajesh, Rathanasamy Rajasekar, Kaliyannan Gobinath Velu, Palaniappan Sathish Kumar, Pal Samir Kumar, Chinnasamy Moganapriya

Polimery

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2019

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T. 64, nr 1

50--55

EN

In rice husk removal processes, the rubber rollers are used to produce white rice kernels. Paddies are fed between two rubber rollers and the removal of husk takes place due to high friction generated between the paddy layer and outer surface of rubber rollers. Husk removal application involves rubber compounds with promising physico-mechanical properties. Small scale rice mills in Tamil Nadu, India face problems in periodic replacement of rubber rollers due to poor service life. Based on thesurvey, it was found that the rubber compounds with high hardness lead to efficient husk removal and at the same time cause break age of rice. Employing soft rubber eliminates the breakage of rice, but on the other hand the sharp corners of paddy damage the rubber. This research work focuses on the development of rubber compounds for effective rice husk removal application. Carbon black filled, pure and blends of natural rubber (NR), acrylonitrile butadiene rubber (NBR), and epoxidized natural rubber (ENR) are developed. Mechanical properties and lab scale rice husk separation studies are conducted for the developed rubber compounds. The ENR-NBR blends prove to be suitable materials for husk removal application.

PL

Usunięcie łusek z ziaren ryżu metodą walcowania pomiędzy rolkami wykonanymi z kauczuku napełnionego sadzą następuje w wyniku tarcia wytwarzanego między warstwą nasion ryżu a powierzchnią rolek. Do tego typu zastosowań potrzebne są mieszanki kauczukowe o specjalnych właściwościach fizyko-mechanicznych. Ze względu na niewielką trwałość dotychczas stosowanych materiałów gumowych, małe młyny ryżu w Tamil Nadu w Indiach borykają się z koniecznością okresowej ich wymiany. Na podstawie przeprowadzonych badań stwierdzono, że rolki wykonane z mieszanek kauczukowych o dużej twardości skutecznie usuwają łuski, ale niestety powodują jednocześnie pękanie ziaren ryżu. Z kolei zastosowanie mieszanek kauczukowych o mniejszej twardości ogranicza zjawisko pękania, ale ostre łuski uszkadzają rolki. Zbadano właściwości mechaniczne i efektywność w procesie separacji łuski ryżowej napełnionych sadzą wulkanizatów kauczuku naturalnego (NR), butadienowo-akrylonitrylowego (NBR), epoksydowanego kauczuku naturalnego (ENR) lub ich mieszanin. Wulkanizaty mieszaniny ENR-NBR okazały się najbardziej odpowiednimi materiałami na rolki do zastosowań w procesie usuwania łuski ryżowej.

5

Development of sol-gel derived gahnite anti-reflection coating for augmenting the power conversion efficiency of polycrystalline silicon solar cells

Kaliyannan Gobinath Velu, Palanisamy Senthil Velmurugan, Palanisamy Manivasakan, Subramanian Mohankumar, Paramasivam Prabhakaran, Rathanasamy Rajasekar

Materials Science Poland

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2019

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Vol. 37, No. 3

465--472

EN

The present research is focused on developing ZnAl2O4 (gahnite) spinel as an antireflection coating material for enhanced energy conversion of polycrystalline silicon solar cells (PSSC). ZnAl2O4 has been synthesized using dual precursors, namely aluminum nitrate nonahydrate and zinc nitrate hexahydrate in ethanol media. Diethanolamine has been used as a sol stabilizer in sol-gel process for ZnAl2O4 nanosheet fabrication. nanosheet was deposited layer-by-layer (LBL) on PSSC by spin coating method. The effect of ZnAl2O4 coating on the physical, electrical, optical properties and temperature distribution in PSSC was investigated. The synthesized antireflection coating (ARC) material bears gahnite (ZnAl2O4) spinel crystal structure composed of two dimensional (2D) nanosheets. An increase in layer thickness proves the LBL deposition of ARC on the PSSC substrate. The ZnAl2O4 2D nanosheet comprising ARC on the PSSC was tested and it exhibited a maximum of 93 % transmittance, short-circuit photocurrent of 42.364 mA/cm2 and maximum power conversion efficiency (PCE) 23.42 % at a low cell temperature (50.2 °C) for three-layer ARC, while the reference cell exhibited 33.518 mA/cm2, 15.74 % and 59.1 °C, respectively. Based on the results, ZnAl2O4 2D nanosheets have been proven as an appropriate ARC material for increasing the PCE of PSSC.