This study examines the impact of cutting regimes on determining cutting resistance in the processing of polypropylene (PP) using the CNC lathe EMCO F5. The rationale for this research stems from ...polypropylene’s rarity among thermoplastics in possessing structural stability, allowing for its comparison to metals and practical application in products replacing metal parts. Leveraging its favorable mechanical properties, polypropylene finds utility in producing parts subject to dynamic loads, boasting high resistance to impact loads—particularly undesirable in machining. An advantageous characteristic of polypropylene is its affordability, rendering it an economical choice across numerous applications. Despite these merits, polypropylene’s exploration in cutting processing remains limited, underscoring the novelty of this research endeavor. The main method for determining cutting resistance involves measuring electric current strength during processing. This direct measurement, facilitated by input cutting regime parameters, is recorded by the PLC controller, with the current value extracted from the machine tool’s ammeter. The experimental approach entails varying cutting regime parameters—cutting speed (v), feed rate (s), and depth of cut (a)—across minimum and maximum values, recognized as pivotal factors influencing cutting force development and the attainment of the desired machined surface quality.
The folowing article considers the process of determining the working temperature of the workpiece in the cutting zone when machining the machine plastic on the lathe. Maintenance of the processing ...temperature of the workpiece in the limits of less than 100 °C is possible with the application and programming of the fuzzy logic controller (FLC) for the required processing conditions.
Programming is established for three inputs and one output and the experimental results refer to generating the value of the acceptable temperature value for the polytetrafluoroethylene (PTFE) processed material, better known as teflon.
Fuzzy logic controller adaptation based on Mamdani rules in this paper is supposed to regulate the number of revolutions of the main CNC machine spindle so that the workpiece temperature could be kept below 100 °C without using a coolant to avoid chemical reactions between the coolant and the base material.
The input parameters for the fuzzy controller are the temperature of the machined material, feed speed and depth of cut and the output is the number of revolutions of the main spindle. Acceptable temperature of the workpiece ranges between ∼20 °C and 100 °C, of the feed speed between 0,05 and 0,089 mm/rev and of depth of cut between 1 and 5 mm.
The paper gives an example of a biogas plant used for electricity and heat production. First, the role and importance of the biogas plant is presented, then an overview of the raw materials used for ...biogas production is given, a project of the biogas plant with constituent elements is given, as well as a description of the technological process and elements of the biogas plant. The calculation of biogas consumption for the needs of the power plant of 0.999 MW has also been performed.
In this paper the analysis and description of the operation of the Premix station for dosing the substrate into existing digesters whose location is in the system of the device for processing of ...liquid waste are described. Apart from the capacity and other entry parameters, the necessary diameter of the pipeline with the length of the section for supplying the devices of the PreMix system is calculated, as it is given in the appropriate tables, the connection of the existing equipment and digesters is presented. The appropriate dependence of the volume flow, the velocity of circulation and power at constant pressure as well as the dependence of the volume flow, pressure and power at constant velocity of circulation are presented by diagrams.
In the petrochemical industry, an industrial pyrolysis furnace is a complicated piece of equipment that functions as both a reactor and high-pressure steam generator. During service, hard deposits of ...carbon (coke) build up on the inner wall of the tube, reducing heat transfer and restricting the flow of the hydrocarbon feedstocks. In this paper, an overview of coke formation, the impact of coke formation, and the methods by which coke formation can be prevented, as well as methods that can be successful in decoking of pyrolysis furnaces, is presented.
This paper will give details of described methods for the laboratory on the examination of biomass energy pellets after they have been through the pressing and cooling process of pressed material. ...These methods are based on previous experiments collected through the literature. The fundamentals of these experiments are examinations of shape and dimensions, moisture content, bulk density, fine particle content, pellet attrition, ash content, and calorific value of energy pellets as they pass throughout the burning process. The examination results will contain a range of data that was gathered. It will contain evidence of physical characteristics of biomass energy pellets. A comparison of characteristics was performed on the basis of the existing literature and standards. After the comparison of the conducted examination, there will be an examination discussed with other sources or ideas formed by other international theorists. It was clear from the findings of the examination that parameters are acceptable, because the results were relatively similar. It is necessary to use the national standard for defining quality energy pellets and briquettes of biomass for the research. National standards regulate the methods for testing the quality of energy pellets and briquettes of biomass.
The paper presents a procedure for determining the optimal amount of thermal energy for the profitable operation of a biogas plant. The temperature at which anaerobic fermentation takes place ...shortens the time of fermentation and biogas production, but also the provision of higher temperatures requires a certain amount of thermal energy, whose consumption reduces the energy effects of the biogas production system. In this paper the results of the average outdoor temperature and the temperature of inlet mass in fermenter are shown by months, the thermal energy is calculated so as the heat losses of primary and secondary fermenter, and the total required thermal energy to heat the fermenter by months is determined. The required thermal energy for heating the fermenter is presented in percentages, on average 16 % in relation to the total produced thermal energy. Careful analysis determined that the temperature for most profitable anaerobic fermentation process (mesophilic temperature is 40.5 °C), so that the fermentation rate would be optimal with the use of minimum amount of thermal energy to heat the fermenter.
The paper analyzes the development opportunities of solar systems in the Republic of Serbia. Renewable energy sources and their energy potential, such as solar energy, should be considered in order ...to meet the needs of consumers. Solar energy can be considered the most modern renewable energy whose utility is still developing, and it is not represented as the utilization of hydro energy sources. Researches show that Serbia is a country with a high RES potential and that it has favorable conditions for production of electrical and heat energy from renewable sources. The aim of this paper is to present the possibilities of using solar energy in Serbia. Energy supply from renewable energy sources is a key factor for each country's strategy, because it directly contributes to reducing the negative effect on the environment.
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