Academic literature on the topic 'Vacuum evaporation method'

Jaggery is a solid unrefined, non- centrifugal cane sugar (NCS) with unique colour, flavor and aroma obtained from crushing of cane and evaporating of sugarcane juice. In this paper vacuum pan evaporation method were used sugarcane juice boiling at vacuum pressure (Vp : 500-700 mm of Hg), time (t:60-90 min) and temperature (T:100-1200 C). The quality attributes of jaggery developed from vacuum pan evaporator were investigated at different process variables. The developed jaggery were analyzed for physiochemical. Results showed that TSS (0 Brix) and Hardness (Hd) increased with increase in vacuum pressure and time, whereas moisture content percentage (%) and water activity (aw) decreased with increase in vacuum pressure and time at variable temperature of 1100 C. Fuzzy logic method was used to evaluate the sensory characteristic of prepared jaggery.

Abstract:Dealing with thallium-bearing materials by vacuum distillation under the condition of 400~700°Cand 10-60 Pa.Measured contents of Cd,Tl and Pb under these temperatures.Analzed relations between evaporation rate,residue duty of Cd with temperatures, and The relyations that between evaporation rate,evaporative duty of Tl and Pb with temperatures.Least square method is used to fit the relations and got that the most suitable temperature for evaporating Cd is 560°C;Analyzed the relations between the activity coefficients ratio of Cd-Tl system and Cd-Pb system and temperatures as well as mole fractions,also got fitted equations of them;Analyzed the relation between gas-liquid cotents of Cd-Tl,Cd-Pb systems and temperatures.It is valuable for extracting Tl,Pb with vacuum distillation.

Fokus penelitian ini adalah alat desalinasi air laut energi surya dengan sistem vakum alami. Salah satu bagian terpenting yang menentukan performansi alat ini adalah proses penguapan pada kondisi vakum di dalam evaporator. Para peneliti umumnya menggunakan cara analitik dengan persamaan-persamaan empirik untuk menentukan laju penguapan pada evaporator.Padapenelitian ini diusulkan menggunakan metode numerik dengan menggunakan perangkat lunak CFD untuk menjelaskan proses penguapan pada evaporator. Hasil numerik dan analitik akan dibandingkan dengan hasil eksperimen. Peralatan eksperimen sederhana telah dirancang bangun untuk mendapatkan hasil eksperimen dan melakukan validasi. Hasil simulasi menunjukkan metode numerik dengan menggunakan perangkat lunak CFD dapat menggambarkan proses penguapan pada evaporator dengan baik. Perbandingan hasil analitik dan numerik menunjukkan laju penguapan di evaporator dengan metode numerik lebih dekat dengan hasil eksperimen. Metode numerik sebaiknya digunakan untuk melakukan inovasi agar dihasilkan peningkatan performansi desalinasi surya sistem vakum alami. The focus of this research is solar energy seawater desalination with a natural vacuum system. One of the most important parts that determine the performance of this tool is the evaporation process under vacuum inside the evaporator. Researchers generally use analytical methods with empirical equations to determine the evaporation rate of the evaporator. This research proposed by using a numerical method with CFD software to explain the evaporation process on evaporator. Numerical and analytical results will be compared with the experimental results. A simple experimental tool has been designed to get experimental results and validate. The simulation results show that the numerical method using CFD software can properly describe the evaporation process in the evaporator. Comparison of analytic and numerical results shows the evaporation rate in the evaporator with numerical methods closer to the experimental results. Numerical methods must be used to innovate so that the performance of solar desalination results increases by using a natural vacuum system.

Honey that has a moisture content above 22% should be done moisture reduction process. reduction of water content is done so that honey does not undergo fermentation and has a longer shelf life. One of the ways that can be used to reduce water content in honey is evaporation. Evaporation is of converting some of the water content in the material into steam by utilizing temperatures close to the boiling point of water. However, the minor content of honey, such as the diastase enzyme, is very sensitive to high temperatures. Therefore, vacuum evaporation is used so that the process uses a lower temperature to minimize the damage to the diastase enzyme. The research method was carried out in 3 stages, namely sampling, evaporation process, and sample testing. The results of this study indicate that the process of vacuum evaporation and vacuum cooling can change the proximate content of cassava honey to comply with SNI.

In this work, thin films of lead iodide (PbI2) were deposited on glass substrates with different thicknesses by vacuum thermal evaporation method. The structural, chemical, electrical and optical characteristics of the thin films were studied. XRD analysis showed that lead iodide film is polycrystalline having hexagonal structure. A particle size was estimated by Williamson - Hall technique (13) nm and strain (4.90*10-3) are founded from the intercept with y-axis and slope for PbI2. The UV-VIS measurements illustrated that the lead iodide has a direct optical band gap and Urbach energy to be 0.677 eV2. Raman peaks are detected at 70, 96, 99.5, 188 and 202 cm-1 which corresponding to characteristic of PbI2 at (E21, A11, 2E11 and A1g). The FTIR spectrum of PbI2 thin film showed six bands at 1650, 1900, 3100, 3400, 3600 and 3800 cm-1. Mechanism of dc transport was also analyzed in the temperature range 315–395 K. Also the variation of reflectivity in the range near infrared is conductive generally attributed to thin film nature, where this film contain light scattering and large surface area, which enhance the optical absorption and hence, a low reflectivity is obtained.

Abstract Washing detergents in process wastewaters from fine chemical industry produce high Chemical Oxygen Demand (COD), which poses a serious environmental problem. Method has to be found, which follows the principles of circular economy so that the treated water can be recycled or reused. Heat pump vacuum evaporator is evaluated in order to reduce the Chemical Oxygen Demand of process wastewater with washing detergent content from initial 7500 mg O2/L to a lower value below the effluent limit , which is 1000 mg O2/L. Yield and COD rejection are determined for the evaluation of selected treatment. Experiments are investigated with LED Italia R150-v3 pilot apparatus. Different evaporation pressures were applied during measurements. It The highest removal or reduction of in the Chemical Oxygen Demand was reached certainly using the lowest possible pressure, which is 40 mbar.

Description de l'automatisation de la phase de la mise en vide d'un groupe a des pressions de l'ordre de 10**(-9) torr à partir d'un microordinateur et de nombreux circuits d'interface. Extension du projet global d'automatisation pour gérer toutes les phases du processus. Description de l'appareillage de mesures analogique ainsi que son interface avec le microordinateur

В даній роботі досліджувався вплив концентрації цинку x на оптичні властивості (спектри пропускання, відбивання та ін.) плівок твердого розчину ZnxCd1-xS, отриманих методом вакуумного випаровування у КЗО.

Соседова, К. Ю. Проєкт міні-заводу з виробництва сиру кисломолочного та сухої молочної сироватки потужністю 70 т переробленого молока за зміну : випускна кваліфікаційна робота : 181 «Харчові технології» / К. Ю. Соседова ; керівник роботи Ж. В. Замай ; НУ "Чернігівська політехніка", кафедра харчових технологій. – Чернігів, 2021. – 67 с.
В дипломному проекті на тему «Проект міні-заводу з виробництва сиру кисломолочного та сухої молочної сироватки потужністю 70 т переробленого молока за зміну» розглянуто і запропоновано технологію приготування сиру кисломолочного, сирків дитячих, сухої молочної сироватки і цукру-сирця. В розділах та підрозділах кваліфікаційної роботи наведено наступне: - у Вступі висвітлено проблеми молочноконсервної галузі, а також користь сиру та сироватки, наведено актуаальність проблеми використання сироватки, як побічної сировини; -у Технологічній частині роботи наведено розрахунок продуктів запроектованого асортименту із зазначенням схеми переробки сировини. Подано опис технологій продуктів, вибір та обґрунтування технологічних режимів виробництва; -у підрозділі Промислова санітарія на підприємстві розглянуто заходи для підтримання чистоти на підприємстві молочного виробництва, проаналізовано принцип HACCP. -у підрозділі Підбір технологічного обладнання було перевірено існуюче та додаткове технологічне обладнання для забезпечення необхідних потужностей та безперервності здійснення технологічних процесів, було оснащенно лінії більш якісним обладнанням; -у розділі Екологічна частина розглянуто причини, пов’язані із використанням безвідходних технологій за рахунок переробки вторинної молочної сировини, охороною природи та її ресурсів, наведено стан екології на підприємстві, вказано шляхи її поліпшення; -у розділі Охорона праці на підприємстві було небезпечних та шкідливих факторів на виробництві, а також шляхи усунення їх впливу на виробничий персонал. Проаналізовано заходи покращення стану охорони праці на підприємстві.
The diploma project on the topic "Project of a mini-plant for the production of sour milk cheese and whey powder with a capacity of 70 tons of processed milk per shift" considers and proposes the technology of making sour milk cheese, baby cheese, whey powder and raw sugar. The sections and subsections of the qualification work contain the following: - The Introduction highlights the problems of the dairy industry, as well as the benefits of cheese and whey, the relevance of the problem of using whey as a by-product; - in the Technological part of the work the calculation of the products of the designed assortment and serial assortment of serizarinog is given. The description of product technologies, choice and substantiation of technological modes of production is given; - in the subdivision of Industrial sanitation at the enterprise measures for maintenance of cleanliness at the enterprise of dairy production are considered, the principle of HACCP is analyzed. - in the subsection Selection of technological equipment the existing and additional technological equipment was checked to ensure the necessary capacities and continuity of technological processes, the lines were equipped with better equipment; - in the section Ecological part the reasons connected with use of waste-free technologies at the expense of processing of secondary dairy raw materials, protection of the nature and its resources are considered, the state of ecology at the enterprise is resulted, ways of its improvement are specified; -in the section of labor protection at the enterprise there were dangerous and harmful factors on the production of measures to improve the state of labor protection at the enterprise.

Recently, there has been a growing interest in semiconductor and semiconducting oxide nanowires for applications in electronics, energy conversion, energy storage and optoelectronic devices such as field effect transistors, solar cells, Li- ion batteries, gas sensors, light emitting diodes, field emission displays etc. Semiconductor and semiconducting oxide nanowires have been synthesized widely by different vapor transport methods. However, conditions like high growth temperature, low vacuum, carrier gases for the growth of nanowires, limit the applicability of the processes for the growth of nanowires on a large scale for different applications. In this thesis work, studies have been made on the growth of semiconductor and semiconducting oxide nanowires at a relatively lower substrate temperature (< 500 °C), in a high vacuum (1× 10-5 mbar), without employing any carrier gas, by electron beam and resistive thermal evaporation processes. The morphology, microstructure, and composition of the nanowires have been investigated using analytical techniques such as SEM, EDX, XRD, XPS, and TEM. The optical properties of the films such as reflectance, transmittance in the UV-visible and near IR region were studied using a spectrophotometer. Germanium nanowires were grown at a relatively lower substrate temperature of 380-450 °C on Si substrates by electron beam evaporation (EBE) process using a Au-assisted Vapor-Liquid-Solid mechanism. High purity Ge was evaporated in a high vacuum of 1× 10-5 mbar, and gold catalyst coated substrates maintained at a temperature of 380-450 °C resulted in the growth of germanium nanowires via Au-catalyzed VLS growth. The influence of deposition parameters such as the growth temperature, Ge evaporation rate, growth duration, and gold catalyst layer thickness has been investigated. The structural, morphological and compositional studies have shown that the grown nanowires were single-crystalline in nature and free from impurities. The growth mechanism of Germanium nanowires by EBE has been discussed. Studies were also made on Silicon nanowire growth with Indium and Bismuth as catalysts by electron beam evaporation. For the first time, silicon nanowires were grown with alternative catalysts by the e-beam evaporation method. The use of alternative catalysts such as Indium and Bismuth results in the decrease of nanowire growth temperature compared to Au catalyzed Si nanowire growth. The doping of the silicon nanowires is possible with an alternative catalyst. The second part of the thesis concerns the growth of oxide semiconductors such as SnO2, Sn doped Indium oxide (ITO) nanowires by the electron beam evaporation method. For the first time, SnO2 nanowires were grown with a Au-assisted VLS mechanism by the electron beam evaporation method at a low substrate temperature of 450 °C. SEM, XRD, XPS, TEM, EDS studies on the grown nanowires showed that they were single crystalline in nature and free of impurities. The influence of deposition parameters such as the growth temperature, oxygen partial pressure, evaporation rate of Sn, and the growth duration has been investigated. Studies were also done on the application of SnO2 nanowire films for UV light detection. ITO nanowires were grown via a self-catalytic VLS growth mechanism by electron beam evaporation without the use of any catalyst at a low substrate temperature of 250-400 °C. The influence of deposition parameters such as the growth temperature, oxygen partial pressure, evaporation rate of ITO, and growth duration has been investigated. Preliminary studies have been done on the application of ITO nanowire films for transparent conducting coatings as well as for antireflection coatings. The final part of the work is on the Au-assisted and self catalytic growth of SnO2 and In2O3 nanowires on Si substrates by resistive thermal evaporation. For the first time, SnO2 nanowires were grown with a Au-assisted VLS mechanism by the resistive thermal evaporation method at a low substrate temperature of 450 °C. SEM, XRD, XPS, TEM, and EDS studies on the grown nanowires showed that they were single crystalline in nature and free of impurities. Studies were also made on the application of SnO2 nanowire films for methanol sensing. The self-catalytic growth of SnO2 and In2O3 nanowires were deposited in high vacuum (5×10-5 mbar) by thermal evaporation using a modified evaporation source and a substrate arrangement. With this arrangement, branched SnO2 and In2O3 nanowires were grown on a Si substrate. The influence of deposition parameters such as the applied current to the evaporation boat, and oxygen partial pressure has been investigated. The growth mechanism behind the formation of the branched nanowires as well as nanowires has been explained on the basis of a self-catalytic vapor-liquid-solid growth mechanism. The highlight of this thesis work is employing e-beam evaporation and resistive thermal evaporation methods for nanowire growth at low substrate temperatures of ~ 300-500 °C. The grown nanowires were tested for applications such as gas sensing, transparent conducting coatings, UV light detection and antireflection coating etc. The thesis is divided into nine chapters and each of its content is briefly described below. Chapter 1 In this chapter, a brief introduction is given on nanomaterials and their applications. This chapter also gives an overview of the different techniques and different growth mechanisms used for nanowires growth. A brief overview of the applications of semiconductors and semiconductor oxide nanowires synthesized is also presented. Chapter 2 Different experimental techniques employed for the growth of Si, Ge, SnO2, In2O3, ITO nanowires have been described in detail in this chapter. Further, the details of the different techniques employed for the characterization of the grown nanowires were also presented. Chapter 3 In this chapter, studies on the growth of Germanium nanowires by electron beam evaporation (EBE) are given. The influence of deposition parameters such as growth temperature, evaporation rate of germanium, growth duration, and catalyst layer thickness was investigated. The morphology, structure, and composition of the nanowires were investigated by XRD, SEM, and TEM. The VLS growth mechanism has been discussed for the formation of the germanium nanowires by EBE using Au as a catalyst. Chapter 4 This chapter discusses the growth of Si nanowires with Indium and Bismuth as an alternate to Au-catalyst by electron beam evaporation. The influence of deposition parameters such as growth temperature, Si evaporation rate, growth duration, and catalyst layer thickness has been investigated. The grown nanowires were characterized using XRD, SEM, TEM and HRTEM. The Silicon nanowires growth mechanism has been discussed. Chapter 5 This chapter discusses the Au-catalyzed VLS growth of SnO2 nanowires by the electron beam evaporation method as well as Antimony doped SnO2 nanowires by co-evaporation method at a low substrate temperature of 450 °C. The grown nanowires were characterized using XRD, SEM, TEM, STEM, Elemental mapping, HRTEM, and XPS. The effect of deposition parameters such as oxygen partial pressure, growth temperature, catalyst layer thickness, evaporation rate of Sn, and the growth duration of nanowires were investigated. The SnO2 nanowires growth mechanism has been explained. Preliminary studies were made on the possible use of pure SnO2 and doped SnO2 nanowire films for UV light detection. SnO2 nanowire growth on different substrates such as stainless steel foil (SS), carbon nanosheets films, and graphene oxide films were studied. SnO2 nanowire growth on different substrates, especially SS foil will be useful for Li-ion battery applications. Chapter 6 This chapter discusses the self catalyzed VLS growth of Sn doped Indium oxide (ITO) nanowires by the electron beam evaporation method at a low temperature of 250-400 °C. The grown nanowires were characterized using XRD, SEM, TEM, STEM, HRTEM, and XPS. The effect of deposition parameters such as oxygen partial pressure, growth temperature, evaporation rate of ITO, and the growth duration of the nanowires were investigated. Preliminary studies were also made on the possible use of self-catalyzed ITO nanowire films for transparent conducting oxides and antireflection coatings. ITO nanowire growth on different and large area substrates such as stainless steel foil (SS), and Glass was done successfully. ITO nanowire growth on different substrates, especially large area glass substrates will be useful for optoelectronic devices. Chapter 7 In this chapter, studies on the growth of SnO2 nanowires by a cost-effective resistive thermal evaporation method at a relatively lower substrate temperature of 450 °C are presented. The grown nanowires were characterized using XRD, SEM, TEM, HRTEM, and XPS. Preliminary studies were done on the possible use of SnO2 nanowire films for methanol sensing. Chapter 8 This chapter discusses the self-catalytic growth of SnO2 and In2O3 nanowires by resistive thermal evaporation. The nanowires of SnO2 and In2O3 were grown at low temperatures by resistive thermal evaporation using a modified source and substrate arrangement. In this arrangement, branched SnO2 nanowires, and In2O3 nanowires growth was observed. The grown nanowires were characterized using XRD, SEM, TEM, HRTEM, and XPS. The possible growth mechanism for branched nanowires growth has been explained. Chapter 9 The significant results obtained in the present thesis work have been summarized in this chapter.

碩士
崑山科技大學
機械工程研究所
99
The study of this thesis is how to use the vacuum decay method to diagnose the evaporative system leak of motorcycles with the fuel injection system. When the engine is at idle, the vapor in the evaporative system is sucked by the intake manifold vacuum. If the parts in the system is broken, the vapor will leak out and pollute the air. In order to test whether the pipe of the system was broken or not, we can check the rate of vacuum decay by using the vacuum decay method. First, one vacuum sensor was installed in the pipe of the evaporative system near the fuel tank. One normally open solenoid valve was installed in canister inlet and another normally closed solenoid valve was installed in the feeder near the intake manifold. The vacuum in the intake manifold at idle was used to suck the vapor in the pipes, canister, and the fuel tank of the evaporation system. The rate of vacuum decay measured by the tank vacuum sensor can decide whether the evaporative system is broken or not. To avoid the engine instable or stall, the idle stability control must be equipped. The program of the fuel injection control and idle stability control was written by using the MatlabSimulink software. The PI feedback controller was to trim the injection period with the help of a wide-band O2 sensor. The opening of the idle air control valve was regulated to stabilize the idle at the same time. To imitate the evaporative system leak, the bronze tubes with 0.5 mm, 0.7 mm, 1 mm, and 1.5 mm aperture were installed in the evaporative system in experiments. The results of experiments prove the vacuum decay method can diagnose the aperture size of the tubes.

AbstractA rare mistake by Otto Stern led to a confusion between density and flux in his first measurement of a Maxwellian speed distribution. This error reveals the key role of speed itself in Stern’s development of “the method of molecular rays”. What if the gas-phase speed distributions are not Maxwellian to begin with? The molecular beam technique so beautifully advanced by Stern can also be used to explore the speed distribution of gases evaporating from liquid microjets, a tool developed by Manfred Faubel. We employ liquid water and alkane microjets containing dissolved helium atoms to monitor the speed of evaporating He atoms into vacuum. While most dissolved gases evaporate in Maxwellian speed distributions, the He evaporation flux is super-Maxwellian, with energies up to 70% higher than the flux-weighted average energy of 2 RTliq. The explanation of this high-energy evaporation involves two beautiful concepts in physical chemistry: detailed balancing between He atom evaporation and condensation (starting with gas-surface collisions) and the potential of mean force on the He atom (starting with He atoms just below the surface). We hope that these measurements continue to fulfill Stern’s dream of the “directness and simplicity of the molecular ray method.”

Evaporation is a process that involves the removal by vaporization of part of the solvent from a solution, with the objective being to concentrate the solution. In the evaporation of solutions containing biological compounds, the volatile solvent can be water or an organic solvent. Organic solvents are frequently used for antibiotics, steroids, and peptides. Often the solution is under a moderate vacuum, at pressures down to about 0.05 atm absolute [1], which is especially important for heat-sensitive biologicals where the temperature should be as low as possible to minimize degradation. The energy source for evaporation is usually steam at a low pressure, below 3 atm absolute [1]. Evaporation processes typically occur after the processes used for the removal of insolubles. They are often used to concentrate a solution just prior to the bioproduct being crystallized or precipitated. Evaporation can often be coupled with extraction: for example, a bioproduct is extracted from an aqueous stream with an organic solvent, and the extract is sent to an evaporator for concentration. In this chapter, the basic principles of evaporation are discussed, followed by a description of the most common types of evaporators for heat sensitive biological products and a discussion of scale-up and design methods. After completing this chapter, the reader should be able to do the following: • Explain the different types of resistances to heat transfer in an evaporator. • Take into account the boiling point elevation in heat transfer calculations for evaporators. • Calculate the heat transfer resistances and residence time for the concentration of a heat-sensitive bioproduct in a falling film evaporator. • Estimate the fouling factor in an evaporator. • Calculate the maximum allowable vapor velocity from an evaporator. • Select an appropriate type of evaporator to use based on the specific operational and product characteristics. • Size evaporators based on specific operating conditions and the expected overall heat transfer coefficient. The main principles to consider for evaporators are heat transfer and vapor-liquid separation. The theoretical basis of these principles will be discussed.

Abstract This chapter covers the practices and procedures used for shape casting metals and alloys. It begins with a review of the factors that influence solidification and contribute to the formation of casting defects. It then describes basic melting methods, including induction, cupola, crucible, and vacuum melting, and common casting techniques such as sand casting, plaster and shell casting, evaporative pattern casting, investment casting, permanent mold casting, cold and hot chamber die casting, squeeze casting, semisolid metal processing, and centrifugal casting.

Molecular dynamics simulations at liquid-vapor equilibrium condition and evaporation condition into vacuum were carried out to investigate the boundary condition for the kinetic theory of gases. The determination method for condensation coefficient α consistent with the kinetic theory is also proposed. It was found that α for argon at an equilibrium state is close to unity near the triple point temperature of the bulk liquid, and decreases gradually as the temperature rises. The velocity distribution of molecules evaporating into vacuum becomes nearly half-Maxwellian near the triple point temperature, and is deformed as the temperature rises.

In this study, the effect of film layer deposited on a metal surface by vacuum evaporation method on the RISA phenomenon was investigated from the view points of surface wettability and quenching velocity. Test rods were made of SUS304 with the outer diameter of 24mm and the length of 150mm. Four kinds of materials, i.e. titanium, zircaloy-II, germanium and silicon, were deposited separately on the half-circumference surface of a SUS304 rod with thickness of 200 nm. It was concluded that the RISA effect was observed on the film-coated surfaces after gamma-ray irradiation, which is similar to that on an oxide layer of SUS304 surface. It was also found that the quenching velocity on film-coated surfaces was much faster than that on an un-coated surface.