Heating Element Research Articles

Investigating the impact of Trombe wall parameters on thermal performance and room temperature in the Iraqi climate

AbstractTrombe wall serves as an effective passive heating element, and its performance is heavily reliant on local climate conditions. This study involved both experimental and numerical analyses of a full‐scale test room equipped with a Trombe wall under Iraqi climate conditions. To facilitate this investigation, an experimental test room was constructed in Kirkuk city with dimensions of 4.0 m × 3.0 m × 2.75 m. In addition, a numerical simulation method based on computational fluid dynamics was developed and a computer code was created to investigate the performance of the system. The accuracy of the developed numerical approach was validated against experimental data collected from the test room. This analysis was conducted specifically for the period of February 17–18, which represents the coldest month of winter in the study area. The performance of the system was assessed with respect to various parameters; air gap width variations (2, 4, 6, and 10 cm), massive wall thickness ranging from 15 to 35 cm with 5 cm increments, channel width options (3, 5, 10, 15, and 20 cm), and vent heights ranging from 5 to 20 cm in 5 cm increments. Furthermore, an investigation of the impact of replacing the air in the air gap with inert gases, specifically argon, krypton, and a mixture of these gases with air was conducted, as well. The outcomes indicate that both the channel width and vent height do not have a significant impact on the system's performance. However, the width of the air gap has a modest effect on system performance, and the best performance was observed with a smaller gap width, specifically 2 cm. The most significant impact on room temperature is observed when the storage wall thickness is varied. In the case of wall thickness of 15 cm, there is a notably higher fluctuation in room temperature between the maximum and minimum values, reaching approximately 16°C. For a wall thickness of 35 cm, however, this fluctuation is significantly reduced to about 3°C. The system efficiency as determined after 24 h of operation period improved significantly when the air was replaced by an inert gases or a mixture of gases in the air gap. Compared to air, the increase in efficiency is about 14.8% for argon, 17.7% for krypton, and 20.6% for the mixture of gases.

Stability Analysis of the Rapid Heating Multilayer Structure Mold by the Contact Error and Thickness of Layers

Rapid heating of the mold surface is necessary for the high-gloss, high-productivity injection molding process. A rapid heating mold system that uses a carbon nanotube (CNT) as a heating element was investigated because of its structure. For CNT web film to be utilized in the injection molding process, heating must be applied inside the mold. That can cause poor contact at the contact area between the mold and the CNT heating element, leading to local temperature deviation and resistance changes that reduce the heating stability of the CNT surface element. Additionally, the multilayer structure of the CNT web film can cause heat-transfer performance variations due to the different layer thicknesses. To address these issues, an adjustable flush was constructed at the contact area between the electrode inside the mold and the insulator to analyze the heating behavior of the CNT heating element as a function of dimensional deviation. The thermal durability of the CNT web film was also evaluated by analyzing the Raman spectra and measuring resistance changes caused by local overheating. The film can withstand high temperatures, with a flush limit value of 0.3 mm. An optimization analysis was conducted to determine the ideal thicknesses of the multilayer CNT web film, insulator, and electrical insulator. Optimal layer thicknesses were found to be 10 μm, 5 mm, and 0.5 mm, respectively. The main variables of the rapid heating mold required for application to the injection process were identified and reflected in the mold design to suggest directions for commercialization.

A novel finite element model for thermally induced machining of Ti6Al4V

Titanium alloys, including Ti6Al4V, are considered hard to cut materials due to their low thermal conductivity, low elastic modules and high chemical reactivity. This leads to high cutting forces and high surface roughness. Thermal assisted machining is used to improve the machinability of Ti6Al4V. To improve the performance of thermal assisted machining, this study investigates how are the cutting force, cutting zones temperatures, chip morphology, shear plane angle and strain rate are affected by the cutting speed and the heating element characteristics during thermally assisted machining of Ti6Al4V. A 2D numerical model simulating orthogonal cutting process was created using ABAQUS/Explicit software. In this model, Johnson Cook constitutive model was used to describe the material behavior during cutting process. Also, Johnson Cook damage model was used to simulate chip separation mechanism. After the verification of the model by comparison with results found in the literature, a number of simulations were run at different levels of four factors: cutting speed (40, 60, 80, 100, 120 and 140 m/min), heat source temperature (200, 400 and 600 °C), heating source distance from the cutting tool (0.3, 0.6 and 0.9 mm) and heating source size/diameter (0.6, 0.8 and 1 mm). Taguchi L18 orthogonal mixed level design was used to plan for simulation runs using Minitab software. ANOVA analysis was used to investigate the significance of the four factors. The response table of means and the main effect of means are used to compare between the four factors and find their ranking. Based on 95% confidence Interval (CI), the results show that cutting speed has a significant effect on cutting force, strain rate, chip compression ratio, cutting tool nose temperature, cutting tool and chip temperature in the secondary deformation zone, average chip thickness at peaks and average chip thickness at valleys and average pitch. This conclusion is based on the P-values which are << 0.05 and the contribution which reaches 99.01%. Similarly, based on P-values (< 0.05) and contributions (up to 12.16%), the heating source temperature has a significant effect on average chip thickness at valleys, chip compression ratio and strain rate. The cutting speed has Rank 1 among the four factors affecting cutting force, cutting zones temperatures, chip morphology, shear plane angel and stain rate. The effect of instantaneous heating directly before cutting process is negligible compared to the effect of plastic deformation and fracture mechanism in the cutting zone.

Tilt Angle Effect on Natural Convection Heat Transfer from an Inclined Array of Square Cylinders

Natural convection heat transfer from an inclined array of square cross-section cylinders is experimentally studied. Three cylinders of side length D = 0.02 m and 1 m length are used to form the inclined array. Three-cylinder axis inclination angles to the horizontal of 30°, 45°, and 60° are considered. The cylinders are heated using an internal heating element of constant heat flux. Surface temperatures are measured along the three surfaces of each cylinder; upper, lower, and the front side at nine points spaced evenly by 10 cm. The local circumference average temperature is obtained at each point. Four center-to-center distances to side length S/D = 1.25, 1.75, 2.25, and 2.75 are used. Local Nusselt numbers and the modified Rayleigh numbers are obtained for each cylinder at each circumference averaged temperature point. Results show that the lower cylinder heat transfer is least affected by the array compared to that of its single one followed by the middle and the upper cylinder for all S/D and the inclination angles used. The Nusselt number is degraded from that of the single cylinder at a small S/D and that degradation decreases as the S/D increases for all angles. It is observed that the Nusselt number enhances at the small cylinder axis tilt angle of 30°, followed by 45°, and 60°, especially at high modified Rayleigh numbers. New novel general empirical correlations for Nusselt numbers are obtained for each S/D using the cylinder axis tilt angle, the modified Rayleigh numbers, and the cylinder number in the array as parameters. A new general correlation is obtained for the array using the modified Rayleigh number, S/D, the cylinder axis tilt angle, and the cylinder sequential order number as parameters. These new correlations will help any engineering applications using such a configuration of the array.

Additive manufacturing of ceramic multi-material heating and ignition elements for a sustainable space access

The continuous advancement in the space industry and in space access has opened the doors to greater global participation and exploration, with numerous nations, institutes and companies now actively engaged in space exploration. This expansion owes much to the progress in commercial space technologies, such as reusable launch vehicles and micro satellites, which have significantly reduced the overall costs associated with space missions, thereby enhancing space accessibility.Nevertheless, to foster further growth, it is necessary to look at further options of making space access more sustainable and cost-effective. For that, it is important to investigate and identify the cost drivers. An example is the use of traditional manufacturing techniques and materials, which come with inherent limitations, notably in terms of design flexibility and performance efficiency. This results in solutions that are not only time-consuming to manufacture but also not the most effective, making it a costly process.To address these challenges, increasing emphasis is being placed on utilising alternative manufacturing methods, such as additive manufacturing technologies combined with high-performance ceramic materials. This aims to reduce the overall number of manufacturing steps for producing a component and to optimise complex and functional parts reducing the overall costs of mass-produced or individually manufactured components, as evident in current studies.The primary objective of this study is to enhance space accessibility through the development, production and optimisation of electrically functional, all-ceramic and multi-material components (heating/ignition elements). For that, the AM technology “CerAM MMJ” in combination with high performance ceramic material are utilised and discussed. Subsequently, these components undergo electrical measurements and tests, and the resulting data is presented and analysed in the following sections.The findings aim to shed light on the current state of the art and whether the additively manufactured, fully ceramic and electrically functional components could represent a more cost-effective alternative to conventionally manufactured components in the future.

A fluorescence viewer for rapid molecular assay readout in space and low-resource terrestrial environments.

Fluorescence-based assays provide sensitive and adaptable methods for point of care testing, environmental monitoring, studies of protein abundance and activity, and a wide variety of additional applications. Currently, their utility in remote and low-resource environments is limited by the need for technically complicated or expensive instruments to read out fluorescence signal. Here we describe the Genes in Space Fluorescence Viewer (GiS Viewer), a portable, durable viewer for rapid molecular assay readout that can be used to visualize fluorescence in the red and green ranges. The GiS Viewer can be used to visualize any assay run in standard PCR tubes and contains a heating element. Results are visible by eye or can be imaged with a smartphone or tablet for downstream quantification. We demonstrate the capabilities of the GiS Viewer using two case studies-detection of SARS-CoV-2 RNA using RT-LAMP and quantification of drug-induced changes in gene expression via qRT-PCR on Earth and aboard the International Space Station. We show that the GiS Viewer provides a reliable method to visualize fluorescence in space without the need to return samples to Earth and can further be used to assess the results of RT-LAMP and qRT-PCR assays on Earth.

Innovative continuous heating-enhance solar still farm- A case study for irrigation in a pistachio orchard

Water scarcity is a global concern that has become one of the main problems for agricultural activities, especially in countries with arid and semi-arid climates like Iran. Sirjan city, a sweltering and arid city in Iran, is one of the locations where its economy mainly relies on pistachio orchards and other agricultural activities, which are highly affected by poor water quality and high TDS of wells. This city's climate, high solar irradiation, sunny sky, and the high requirement for distilled water for irrigation make utilizing solar power and solar-still desalination systems a reasonable choice. However, the low water production rate of conventional solar still systems prevents the use of this technology in field-scale projects and real agricultural activities. Therefore, we mixed solar still and solar power, to enhance the water production rate and provide water with proper TDS for a pistachio orchard in Sirjan City. In comparison to conventional solar still, the proposed continuous heating-enhanced solar still benefits from several improvements, including passing water through the grooved glass that leads to lowering the glass temperature, increasing water basing temperature by a heating element, polyurethane isolation of basin and capability of working during day and night. The mentioned improvements will lead to an increase in daily water production by 21% from 5.5 to 6.6, 24% from 5.5 to 6.8, 31% from 5.5 to 7.2, and 44% from 5.5 to 7.92 respectively. Therefore, utilizing all the mentioned approaches leads to a 120% increase in daily water production from 5.5 to 12.17 L and in comparison, to the conventional mechanisms, significantly reduces the required area for the system. The results showed that the proposed method is highly effective and could be used in real agricultural activities in arid and semi-arid climates.

Dynamics of changes in the temperature coefficient of electrical conductivity of distilled water in conductometric cells during heating and cooling

The problem of taking into account the influence of air on the properties of distilled water is considered, namely the lack of a single generally accepted method for calculating such an influence. The sensitivity of the structure of water to the influence of external factors is described and the possibility of recording and studying such factors by changes in the temperature coefficient of electrical conductivity of water is shown. The dependences of the temperature coefficient of electrical conductivity of distilled water on the rate of change in water temperature, the degree of filling of conductometric cells, as well as on the intensity of the exchange of carbon dioxide between water and air across their interface have been studied. It is noted that these metabolic processes are currently insufficiently studied. A hardware-software measuring complex has been developed and manufactured to study the temperature coefficient of electrical conductivity of water when its temperature changes within the range of 20–55 °C. The temperature coefficient of electrical conductivity of water in sealed conductometric cells was measured at different degrees of filling the cells with distilled water and the rate of heating and cooling of water. The degree of filling of the cells varied within the range of 10–100 %, the rate of change in water temperature varied within the range of 0.04–2.00 °C/min. With a constant heating and cooling time of 15 minutes in all experiments, the change in speed was achieved by changing the temperature of the heating element. The integral temperature coefficient of electrical conductivity is calculated based on the initial and final values of electrical conductivity and water temperature in each measurement cycle. The dependences of the temperature coefficient of electrical conductivity on the rate of change in water temperature at several constant degrees of cell filling were obtained. It has been shown that with a constant ratio of the volumes of water and air in the cell and an increase in the rate of heating of water, the temperature coefficient of electrical conductivity of water decreases by 19–22 %. It has been established that at a constant rate of water heating, with a decrease in the volume of water in the cell, the temperature coefficient of electrical conductivity of water decreases by 40–42 %. The results obtained can be used to quantify the dissociation coefficient of carbonic acid, the mobility of hydrogen ions, as well as the intensity of the gas exchange process under various external influences on water. Refinement of data on the electrical conductive properties of water and processes at the water/air interface is necessary for the development of models of atmospheric phenomena and climate change, as well as for the creation of sensors for weak changes in environmental parameters for the purposes of both environmental monitoring and medical diagnostics.

High-temperature planar heating elements using RuO2 nanosheets

Planar heating elements employ carbon nanotubes, graphene, and metals. However, the high-temperature (300–500 °C) applications of heating elements based on metallic and organic materials are limited because they oxidize at high temperatures. Oxide materials such as RuO2 are promising alternatives. The electrical conductivity of heating elements are strongly dependent on the aspect ratios of fillers; thus, RuO2 nanosheets are suitable fillers for high-temperature planar heating elements because RuO2 remains stable at high temperatures, and RuO2 nanosheets have high aspect ratios of over 1000, as the lateral sizes and thicknesses of the RuO2 nanosheets are 2∼5 μm and 1–3 nm, respectively. Consequently, the electrical conductivity of planar heating elements using RuO2 nanosheets as fillers is 940 times higher than that of heating elements using conventional granular RuO2 nanoparticles. Therefore, the RuO2 nanosheet-based heating elements will be suitable in various applications requiring high temperatures and high uniformity.

Characterization of the acoustic pressure waveforms in Rijke tubes with spatially varying heat sources and temperature distributions

In this work, we implement an asymptotic expansion technique that leverages a small perturbation parameter that arises in the context of one-dimensional tubes with open-open end point configurations and spatially varying heat sources. This approach, when paired with a spectral collocation eigensolver, enables us to produce accurate predictions of the pressure mode shapes and frequencies over a wide range of parameters. These include the temperature gain across the heat source, the heat source length and location, and the overall thermal profile. The latter is intended to reproduce different flow heating configurations that emulate Rijke tube characteristics. Specifically, this investigation begins by considering three piecewise representations of the heat source by juxtaposing constant–constant temperatures before and after a heating element whose temperature is prescribed locally using three analytical functions: linear, exponential, and power-law profiles. This is followed by a logistic distribution that can be globally applied to provide a uniformly valid, continuous, and differentiable thermal profile spanning the entire tube, including the heat source element. Our fundamental formulation relies on Green's functions and an integral formulation that enables us to extract all acoustic frequencies analytically. These are found to increase monotonically with successive elevations in the temperature gain across the heat source, retractions of the heat source, length reductions in the heat source, and smoothing of the temperature gain. Along similar lines, the pressure mode shapes are found to exhibit blunter and often linear variations for higher temperature gains, longer heat sources, and upstream displacements of the heat source toward the inlet.

VDM 40 B

Abstract VDM 40 B is an austenitic iron-nickel-chromium-silicon-lanthanum alloy that is suitable for heating elements. It is characterized by excellent oxidation resistance, high resistivity, good sag resistance, and superior mechanical properties at high temperatures in comparison to other heating element alloys. VDM 40 B is less expensive than 60Ni, the traditional material for heating elements. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on high temperature performance, corrosion resistance, and surface qualities as well as forming and heat treating. Filing Code: SS-1366. Producer or source: VDM Metals GmbH.

Energy-Technology Indicators of a Multi-Drum Electric Furnace for Firing Vermiculite Concentrates

The design and working process of a new electric drum furnace for heat treatment of vermiculite concentrates and conglomerates, as well as other bulk porous materials based on a silicate binder, are considered. The electric drum furnace is devoid of the disadvantages inherent in its predecessors – furnaces with a movable hearth platform: there are no oscillating elements, dynamic effects do not occur, and there is also no resonant mode of operation, since the working drums perform rotational motion with a constant angular velocity. Using the example of a six-drum furnace, the volumes of processed material located in the firing spaces are calculated, and the second and hourly productivity of the furnace (10 m3/h or 0.0029 m3/s) are determined. The temperature of the heating elements (1167 K) was calculated, the electric power of the furnace (95.2 kW) and the specific energy intensity of the firing process of vermiculite concentrate, with a dimension of 4 mm (0.004 m) from the raw materials of the Kovdorsky deposit – 44.2 MJ/m3, which makes the furnaces of the new design competitively capable, were determined.

Electrical and electrothermal characterization of silver-coated Vectran and Amberstrand yarns for wearable heating

The development and manufacturing of conductive fibers, yarns, and fabrics is increasing exponentially due to their multiple applications in wearable electronic textiles in sensors, actuators, data processing, communication, and energy storage. This paper investigated the electrical and electrothermal properties of Liberator 40 yarns and Amberstrand 166 conductive yarns for application in wearable heating textiles. The aim of the study was to find a flexible material for protective wearable resistive heating cloths in cold environments. The analytical results demonstrate that the Liberator 40 conductive yarn gave better heating performance than the Amberstrand 166 conductive yarn due to its electrothermal characteristics. In addition, Liberator 40 conductive yarn had higher long-term durability, washing resistance, and thermal stability than Amberstrand 166 conductive yarn. The average surface temperature of both the Liberator 40 and Amberstrand 166-based wearable heating fabrics was 40°C and 34.5°C at a 9 V DC power supply, respectively. Therefore, both the conductive yarns are suitable to be applied as resistive heating elements for localized wearable heating textiles.

Remaining Useful Life Estimation of MoSi2 Heating Element in a Pusher Kiln Process.

The critical challenge of estimating the Remaining Useful Life (RUL) of MoSi2 heating elements utilized in pusher kiln processes is to enhance operational efficiency and minimize downtime in industrial applications. MoSi2 heating elements are integral components in high-temperature environments, playing a pivotal role in achieving optimal thermal performance. However, prolonged exposure to extreme conditions leads to degradation, necessitating precise RUL predictions for proactive maintenance strategies. Since insufficient failure experience deals with Predictive Maintenance (PdM) in real-life scenarios, a Generative Adversarial Network (GAN) generates specific training data as failure experiences. The Remaining Useful Life (RUL) is the duration of the equipment's operation before repair or replacement, often measured in days, miles, or cycles. Machine learning models are trained using historical data encompassing various operational scenarios and degradation patterns. The RUL prediction model is determined through training, hyperparameter tuning, and comparisons based on the machine-learning model, such as Long Short-Term Memory (LSTM) or Support Vector Regression (SVR). As a result, SVR reflects the actual resistance variation, achieving the R-Square (R2) of 0.634, better than LSTM. From a safety perspective, SVR offers high prediction accuracy and sufficient time to schedule maintenance plans.

Optimization of Hot Gas Welding of Hybrid Thermoplastic-Thermoset Composites Using Taguchi Method

In this study, the influence of four different process parameters on hot gas welding of CF/epoxy fiber composites functionalized with a PA6 thermoplastic film is investigated. Additional experiments are carried out on specimens adorned with triangular beads of coupling material that are printed onto the plates, ensuring extra material within the joining zone. This approach offers a great advantage for compensating geometric tolerances. The parameters considered are common process parameters for regular two-step processes: Heating element temperature (THE), heating time (HT), welding force (F) and welding time (HTF). The design of experiments (DoE) is planned according to the Taguchi method. An orthogonal array is used to set up the experimental plan. Three factor levels of each welding parameter are considered. The test series are carried out with two sample variants. In the second sample variant, additional thermoplastic material is placed in the joining zone. The strength of the welded joints is investigated by tensile shear tests according to DIN EN 1465. The results show that the welding force has the greatest influence on the welding strength. Heating times of 20 s were found to be optimal. Within the first sample variant, a saturation behavior of the welding force can be observed at 500 N. Higher heating element temperatures (500 °C) and welding forces (1165 N) are advantageous using additional material. High welding temperatures result in a negative effect on the interdiffusivity of the polymer chains.

Implementation of the inverse problem for on-chip PCR diagnostics with rapid and precise thermal cycling

Microfluidic devices have emerged as a promising platform for point-of-care biological analysis, including PCR-based molecular diagnostics. However, the multi-layer characteristics of existing microfluidic chips introduce significant thermal inertia, resulting in temperature disparities between the PCR mixture and the heating element. This issue poses a substantial obstacle to the efficient and accurate deployment of point-of-care technology. Herein, a practical approach for accurate and fast PCR on microchips based on the inverse heat transfer problem (IHTP) is introduced and solved by incorporating computational fluid dynamics (CFD) simulations and the particle swarm optimization (PSO) algorithm. The methodology successfully resulted in a 46% reduction in PCR duration with less than 0.1 ℃ temperature discrepancy for our custom-built microfluidic device. The optimization performance was further evaluated by conducting biological tests at varying concentrations of the genetic sequence, and the standard curve of our optimized PCR system is presented. According to the standard curve of the system, using an optimized boundary temperature profile, the fabricated benchtop testing device performed COVID-19 molecular detection with 104% efficiency. The numerical approach can be extended to a variety of microfluidic devices and PCR temperature protocols, thereby enhancing the PCR diagnosis in microfluidic devices.

Thermal characteristics of multilayer sandwich Nomex honeycomb core composite with heating elements for railways wall panels

The composite material has been widely used in vehicle interiors, particularly in applications such as the wall-side panels of railways. The sandwich honeycomb composite, which combines two composite skins with a metal honeycomb, is the preferred structure in aerospace and railway applications due to its rigidity at minimal weight. As a functional composite material that provides heat flux to passengers, a multilayer sandwich Nomex honeycomb core composite with heating elements has been developed. In this design, the heating element is inserted into the inner composite material as a heat generation component, producing heat transferred to the other side of the panel. The thermal and structural behaviors of the sandwich composite with heating elements are orthotropic and require careful assessment to understand the material characteristics of the developed composite parts. In this study, conduction heat transfer in the functional honeycomb composite is simulated using the Finite Element Method (FEM) and validated with experimental results. The study proposes three steps to solve the problem: determining the heat-transfer parameters, simplifying the Nomex honeycomb core, and conducting a full-scale heat-transfer simulation. This research aids operating systems in controlling the heat generator input to prevent dangerous conditions. The results indicate that the simulation trends closely align with the experimental results.

Pizza Oven Processing of Organohalide Perovskites (POPOP): A Simple, Versatile and Efficient Vapor Deposition Method

AbstractHybrid vapor deposition is one of the most appealing processes for perovskite photovoltaics fabrication, thanks to its versatile nature. By using sequentially different vapor deposition processes tailored to the inorganic and organic perovskite precursors' peculiarities, this type of process gives access to the full potential of vapor deposition. While vapor deposition of metal halides is well understood and mastered, vapor deposition of organohalide species is much more delicate (degradation of vapors, high vapor pressure, setup‐specific constraints). Here, a novel close space sublimation system is reported and in‐depth insights on the conversion into perovskite of a metal halide template are provided. In this evolution of the process, the substrate coated with metal halide template and the organohalide source are loaded together in a dedicated holder, then transferred into a vacuum chamber on a heating element already at temperature setpoint. The system enables a simple, fast, low‐cost, and easy‐to‐reproduce organohalide vapor deposition process. The formation of the perovskite in situ and identification different conversion regimes are studied. Furthermore, the influence of the chemical environment and chamber design on the process are discussed. Compositional tuning and additive engineering in the process are processed and fabricate proof of concept photovoltaic devices reaching high fill factors of 80% and 17% power conversion efficiency for a bandgap of 1.63 eV.

Badania wpływu pola magnetycznego na proces tworzenia kamienia w urządzeniach termicznych

Water is used as working fluids in hydro and thermal power engineering, as well as in heat supply and cooling systems. In the process of heating water in water-heating boilers, scale forms due to the precipitation of crystals of mineral additives and mineral salts. Over time, the accumulation of scale with low thermal conductivity leads to a decrease in the internal diameter of the pipes. Consequently, the flow of liquid is hindered, the hydraulic resistance increases and the thermal conductivity of the device decreases. The scale layer is usually removed by acid washing of the internal heat exchange surfaces or mechanical washing. However, both methods involve the use of a substantial amount of chemicals and result in highly polluted wastewater. In addition, it significantly increases operating costs. The article uses statistical methods for processing experimental data, and generally accepted methods for conducting experiments to study the patterns of scale formation using control and measuring instruments and accurate methods for measuring technological parameters. The main purpose of the paper is to study the influence of a constant magnetic field on the formation of mineral salts deposits on the surface of walls of thermal appliances used in chemical, oil refining, and food processing industry. The influence of a constant magnetic field on the formation of scale on the surface of the walls of the heating element in a water heater has been established. According to the results of an experiment aimed at preventing the accumulation of mineral salt deposits on the surface of the heating element in a water heating boiler under the influence of a magnetic field, the amount of mineral salt precipitate deposited on such surface can be reduced up to 5.2 times. Consequently, the prevention of mineral scale formation is achieved, eliminating the need to use expensive chemicals. The stable operation of the devices contributes to enhanced thermal efficiency. Under the influence of a magnetic field, scale formation decreases on average by a factor of 5, as long as the water temperature does not exceed 70°C. However, if the temperature rises above 90°C, the scale formation rate gradually increases.

Pembuatan Konsep Alat Preparasi Material Cangkang Kapsul Lunak Menggunakan Metode Pahl &amp; Beitz

Softgel capsule is a capsule with soft shell texture and is used for fluid or semi-solid medicine substance. Research about softgel capsule in Politeknik Negeri Bandung uses a preparation device to mix the soft capsule shell ingredients. In its operation, this machine has several problems: ineffective method of loading and unloading of materials, unsuitable power for the mixing motor and heating element, and the control system still needs to be improved. Based on these problems, it is neccesary to reverse engineer the preparation device to get better design results so that the device can be operated more effectively. This study consists of three stages: planning, concept generation, and concept evaluation. At the planning stage, data is collected and compiled using the Quality Function Deployment (QFD) method to support the creation of requirement lists. In concept generation stage a design concept was created using the Pahl &amp; Beitz method which was then evaluated using the Pugh weighting method until the final concept was obtained. There are three subfunctions: (1) lifting mechanism, (2) control system, and (3) unloading mechanism. The results of this study are a design concept with rack &amp; pinion lifting mechanism, electrical control system, and sliding valve unloading mechanism.