Volume 30, No. 3 (2024)

ASPECTS REGARDING THE STUDY OF HYDRAULIC AND MECHANICAL PARAMETERS OF A ”SPIDER CRANE” SYSTEM

NICUŞOR BAROIU(1*), VIOREL PĂUNOIU(1), VIRGIL GABRIEL TEODOR(1), GEORGIANA-ALEXANDRA MOROŞANU(1), RĂZVAN SEBASTIAN CRĂCIUN(1)

Since it is acknowledged that transport and lifting installations play an extremely important role in industry, construction, and the extractive field, as well as in the mechanization of loading-unloading works, the movement of equipment or materials, special attention is paid to the growth and diversification of such installations at the level of the most advanced technologies. The paper presents the operating principles and characteristics of a lifting and transport installation known as a ”Spider Crane”. This installation is considered a more cost-effective and efficient alternative to traditional cranes for works where lifting requirements are below certain limits and significant heights. Thus, an analysis of the hydraulic lifting system is carried out, based on the calculation of hydraulic fluid flows for the drive pumps, the specific speeds and forces of the hydraulic cylinders, a mechanical analysis of the clamping system with hook, as well as a finite element analysis of some mechanical and hydraulic components.

ANALYSIS OF CRANKSHAFT DEFECTS FROM AUTOMOBILE INTERNAL COMBUSTION ENGINES AND THEIR CLASSIFICATION

IVANOV IVAN HRISTOV(1,2*)

The following research investigates the main damages that the crankshafts from internal combustion engines may experience. Operational damage is associated with significant changes in shape, dimensions and mutual arrangement of their surfaces. Defects are classified as natural (primary) and consequential (secondary), and are caused by failures in other components that make up the engine.

AN EVALUATION OF YELLOW OLEANDER (THEVETIA PERUVIANA) SEED OIL AS A CUTTING LUBRICANT USING THE EXAMPLE OF MEDIUM CARBON STEEL FOR TURNING ON THE LATHE MACHINE

GUMA THOMAS NDYAR(1*), ALHASSAN ABDULLAHI(1)

The yellow oleander (YO) is a notable plant of great technological importance. It grows naturally and is grown agriculturally widely and abundantly in Nigeria and many other countries around the globe. The potential of using pure oil extract from YO seed as a more environmentally friendly alternative cutting lubricant to the conventionally and widely used soluble oil was investigated in terms of some basic physicochemical properties, work cooling, and surface finishing performance using, for example, medium-carbon steel as the workpiece in turning on the lathe machine. The kinematic viscosities, pH values, unsaturated oleic acid contents, free fatty acid contents, flash points, pour points, and chloride contents, as well as the cooling and surface finishing capabilities of the steel by the two oils, were experimentally evaluated. The Soxhlet technique was used to extract the YO seed oil. The evaluated kinematic viscosity at 100 oC, pH value, unsaturated oleic acid content, free fatty acid content, flash point, pour point, and chloride content of the YO seed oil through various ASTM and other standard methods were 21.13 cSt, 8.66, 31.23%, 0.91%, 191 oC, 1 oC, and 0.16%, respectively, while the respective values for soluble oil were 19.27 cSt, 6.51, 20.62%, 2.10%, 171 oC, 3.18 oC, and 0%. Comparative analyses of the YO seed oil and soluble oil values indicate a lower ability of YO seed oil to flow than soluble oil, an insignificant corrosivity difference between the two oils, better lubricity of YO seed oil than soluble oil, less tendency of YO seed oil to oxidize and become rancid than soluble oil, less proneness of YO seed oil to fire hazards than soluble oil, better suitability of YO seed oil for cold regions than soluble oil, and higher sterility and tendency towards increased emulsion life of YO seed oil. Turning experiments indicate that the two oils have similar cooling and surface finishing effects on medium-carbon steel. The overall information and analyses suggest that YO seed oil can be extracted sustainably in large quantities in many countries around the world, including Nigeria, and used effectively as a more environmentally friendly alternative lubricant to soluble oil in metal cutting operations such as turning medium-carbon steel on the lathe machine.

PARAMETRIC STATISTICAL SIGNIFICANCE OF LEAD (II) IONS ADSORPTION BY RICE HUSK IN AQUEOUS SOLUTIONS

BABATOPE OLUFEMI(1*), SALAUDEEN HUSSEIN(1), ALABI HABEEB(1)

Batch experiments were performed to determine how Pb (II) ion adsorption was affected by contact time, adsorbent dosage, temperature, and pH. Adsorption increased with higher adsorbent doses and decreased with higher adsorbate doses. Time speeds up the adsorption process, with pH 6 and 650 °C showing the highest levels of adsorption. The Langmuir and Dubinin-Radushkevic isotherm models best fitted the sorption data, with R2 values of 0.995 and 0.9956 and standard errors of regression of 1.8209 and 0.0298, respectively. The pseudo-first order kinetic model best captured the kinetics. Analysis of Variance (ANOVA) and the Bonferroni-Holm Posthoc significance test showed that the adsorption was statistically and parametrically justified.

REGRESSION ANALYSIS OF FACTORS AFFECTING ZINC RECOVERY IN ROTARY KILNS

DIDEM OZCAN(1), KURSAT MUSTAFA KARAOGLAN(2), MEHMET CELIK(3*)

With the rapid increase in global industrialization, the demand for zinc constantly increases while primary zinc resources gradually decrease. This situation makes the recovery of zinc from secondary sources a strategic priority from a circular economic perspective. Electric arc furnace (EAF) dust, an essential iron and steel industry waste, is a valuable secondary resource due to its high zinc content. Therefore, zinc recovery is an attractive option, given its low production cost. This study conducted an experimental analysis of the zinc recovery process from EAF dust in rotary kilns. Operational data obtained from an industrial-scale plant were used. The data set included EAF dust amount, iron content in EAF dust, lime content, coal used, slag amount, and zinc grade in slag. Multiple Linear Regression (MLR) analysis was applied to determine the relationships between the parameters. The MLR analysis calculated the multiple correlation coefficient (R) as 0.661876, and statistically significant relationships were determined between process parameters and slag formation. The findings provide a systematic and innovative approach for optimizing process parameters and controlling slag formation in industrial-scale zinc recovery processes. The analysis results indicated that raw material quantities and iron content in EAF dust significantly affect slag formation, contributing to zinc recovery efficiency and waste minimization. The developed model allows the systematic understanding and control of the effects of process parameters on slag formation while also providing a solid basis for future optimization studies.

THE ORIGIN AND TREND OF ORANGE WINES

SCLIFOS ALIONA(1*), COVACI ECATERINA(1)

The present paper examines the genesis and trend of orange wines, as well as the potential of the local market to integrate this type of wine and the role of sustainability and durability in strengthening the creation of biodynamic wines. The research focused on the investigation of the local white grape variety Viorica from the Purcari area, examining the grapes, the procedures used to get the raw material wine intended for the production of Orange wine, and wines from the 2020 and 2022 harvests. After getting the wine raw material, the organoleptic properties were analyzed and the key parameters were evaluated, which revealed that they correspond to the documents in force.