Vacuum Oil Research Articles

Single-stage NBI sampler for PM1 mass and five-stage NBI-NMCI sampler for PM1 mass distribution measurements

In recent years, concerns about the health and environmental risks associated with PM1 particles have increased. However, existing PM1 sampling instruments remain to be improved mainly because their PM1 inlets have particle loading and bounce issues. To address these challenges, PM1 inlets based on the Non-Bouncing Impactor (NBI) technique were developed. These inlets employ vacuum oil-wetted glass fiber filter (GFF) substrates to eliminate particle bounce and incorporate a daily vacuum oil injection to prevent particle loading. The 16.7 L/min PM1 NBI, modified from the PM2.5 M-WINS design with a reduced diameter of the single nozzle, was designed to adapt readily with current standard sampling and monitoring systems. The cut-size (Dpa50) of 0.99 ± 0.02 μm was determined by considering the effects of Reynold number and the ratio of jet-to-plate distance and nozzle diameter. Field tests comparing the 16.7 L/min PM1 NBI sampler to the 9-stage NCTU Micro-orifice Cascade Impactor (NMCI9) revealed small sampling biases, with a mean difference of +0.26 ± 2.28 μg/m3 for PM1 measurements when silicone oil-coated aluminum foil (AF) and GFF-AF were used in the NMCI9. The NBI with the oil-wetted GFF substrate effectively removed particles larger than 1.0 μm, resulting in more accurate PM1 mass concentration measurements. Additionally, the development of a 5-stage NMCI with the 30 L/min PM1 NBI as the first stage enabled detailed measurement of PM1 mass distribution in two modes, which was challenging when measuring the entire mass distribution of ambient aerosols. The distribution of size-dependent water-soluble inorganic ions in PM1 showed dominance of SO42− and NH4+ in PM1 compared to PM2.5. In summary, the PM1 NBI enhances accuracy for long-term atmospheric sampling by addressing particle loading and bounce, making it a more reliable standard sampling instrument.

Phlegmatization of TATP using a Vacuum Oil: Comparison with Diesel Oil and Demonstration of the Effect using a Large‐Scale Impact Tester

Phlegmatization of TATP using a Vacuum Oil: Comparison with Diesel Oil and Demonstration of the Effect using a Large‐Scale Impact Tester

Influence of Water Concentration on the Water/Vapor/ Oil Separation Process in a Vacuum Oil Filter: Modelling and Simulation

The vacuum oil filter (VOF) is widely applied in the oil-water emulsion demulsification separation due to the phase separation by using vacuum evaporation; however, the micro-dynamic characteristics of oil, water and vapor three phases and the influencing factors of separation efficiency are rarely studied. Therefore, the fluid flow and phase separation characteristics of water-in-oil emulsions were numerically analysed by ANSYS software. The demulsification conditions of water/oil emulsion were simulated by using the two-fluid model and the water evaporation model, and the turbulence effect was considered by using the Reynolds stress model. The results show that the established model could provide a convenient way to study the effects of the different water concentrations in oil; the turbulence intensity in VOF increases with the increase of water concentration in oil; The separation efficiency has been influenced by the inlet water concentration reaching values between 20.65-22.62% in the center axis, while 33.18-42.24% in the plate column; the vapor concentration ranged from 0 - 23.64% in the center axis, while 0 - 41.02% in the plate column. The relative volume fraction of water concentration decay tending with the water concentration increases, and the water concentration has a great influence on the separation efficiency.

Activation of carbon sorbents used in the hydrocracking process of vacuum oil distillation residue

Activation of carbon sorbents used in the hydrocracking process of vacuum oil distillation residue

Effect of a high-gradient magnetic field on particle concentration distribution in a magnetic fluid seal: Rivalry of the diffusion and magnetophoresis

In this paper, the unsteady process of particle concentration distribution in a magnetic fluid is studied. Diffusion and the effect of a high-gradient magnetic field in a magnetic fluid seal (MFS) are taken into consideration. It is crucial to take into account how particle mobility and diffusion coefficient vary on particle concentration in order to determine the possibility and time of the formation of a close packing of particles. The Carnaghan-Starling approximation was employed. It is demonstrated numerically that the geometry of the MFS, namely its gap width and pole base width, as well as the magnitude of the magnetic field strength under the pole tooth of the MFS, both influence the time of the formation of a close packing of particles. This period can be regarded as the MFS's uptime. Depending on the design of the working gap, the uptime seal for magnetic fluid based on vacuum oil may require between two weeks and six months. The uptime seal also becomes shorter when the carrier fluid's viscosity decreases.

Intelligent Control System of Vacuum Oil Filter Based on PLC

Intelligent Control System of Vacuum Oil Filter Based on PLC

Liquid Level Control System for Degassing Chamber of Vacuum Oil Filter Based on Fuzzy PID

This paper proposed a fuzzy PID control method to address the complexities associated with the inertia and nonlinear variations in liquid level control within the degassing chamber of vacuum oil filter. Tailored to meet practical control demands, a fuzzy control rule table was devised. This solution was simulated and applied in MATLAB/Simulink. The results indicated that, in comparison to classic PID, fuzzy PID exhibited faster adjustment speed and reduced overshoot, making it a more suitable option for vacuum oil filter applications.

Effects of Nickel Promotion on the Catalytic Performance of In Situ Synthesized Suspensions of Molybdenum Disulfide Nanoparticles

The study investigates the activity of in situ synthesized suspensions of nickel-promoted molybdenum disulfide particles in the hydroconversion of crude oil vacuum residues. The catalyst suspensions were prepared in situ from water-in-oil emulsions of aqueous solutions of precursors, specifically ammonium paramolybdate and nickel nitrate. The catalytic tests were carried out in a flow-type reactor at 430°C, WHSV 1 h–1, and 7 MPa hydrogen, with the Mo:Ni atomic ratio in the catalyst particles ranging from 1:0.022 to 1:1.43. The XRD of the toluene-insoluble solids (TIS) extracted from the hydrogenates identified sulfides such as MoS2, Ni3S4, and Ni3S2 in the dispersed catalyst. Increasing the nickel content in the catalyst favored its hydrogenation activity, which was indicated by an enhancement in the feed conversion, an increase in the content of paraffins and naphthenes, and a decrease in the sulfur content in the distillates and TIS derived from the hydrogenates. The conversion of high-molecular-weight feed components (resins, asphaltenes, and heavy aromatics) was enhanced as a result of the nickel promotion of the dispersed MoS2.

Use of Vacuum to Increase the Effectiveness of X-Ray Tube Maintenance

Each device requires redundancy, including the X-ray machine. In an X-ray machine, there is an important component as the location for the creation of X-rays, namely the X-ray tube. This tube needs routine maintenance to increase the tube's lifetime. In addition, maintenance that was originally done manually, with this device can be done automatically and more quickly. In addition, maintenance that was originally done manually can be done automatically and faster with this device. X-ray tube oil vacuum is used as an effective solution for the maintenance of an X-ray tube machine that lasts for days. This device comes with easy use, equipped with two buttons and a display. This device can increase the productivity of both the device and the technician itself. The application of the use of X-ray tube oil vacuum is intended for hospitals and health facilities that have active X-ray machines. This device has been able to be built. Based on the results, it has a 2.5% error for the measurement at minimum and maximum pressure and a 3% error at -15 KPa pressure. The volume of the X-ray tube fully filled is always the same for each measurement. It can be concluded that this device can be effective in time because it only takes minutes to fill the X-ray tube up to full. Still, many parts can be improved and developed, such as the size and the weight.

Retracted: High Efficiency Compound Vacuum Oil Gas Separation Technology Based on Integrated Oil Filter of Ultra-High Voltage Transformer

Retracted: High Efficiency Compound Vacuum Oil Gas Separation Technology Based on Integrated Oil Filter of Ultra-High Voltage Transformer

Comparison of the Particle Size Distribution and Vapor Phase of Electronic Nicotine Delivery Systems Using Two Impactors

Summary Electronic Nicotine Delivery Systems (ENDS) contain numerous volatile aerosol constituents (e.g., nicotine, propylene glycol, flavors, etc.). Past work clearly indicates the temporal and chemical dynamics of ENDS aerosol requires consideration of these volatile constituents when measuring the particle size distribution. An MSP-135-8 Mini MOUDI™ and Electrical Low Pressure Impactor (ELPI®+) were used to measure the particle size distribution of two JUUL ENDS products. Volatile chemicals were measured from each cascade impactor's exhaust airflow to assess their effect on collection efficiency. Similar mass median aerodynamic diameters were obtained for both ENDS products by both cascade impactors, however the geometric standard deviation from the ELPI®+ measurements were larger for both products than measurements using the Mini MOUDI™ impactor. Although the measured mass of volatile chemicals was greater in the exhaust from the Mini MOUDI™ impactor, a greater variety of volatile chemicals were found within the exhaust of the ELPI®+. The greater variety of volatile chemicals correlated with more room air sampling by the ELPI®+. The reduced amount of volatile chemicals measured in the exhaust of the ELPI®+ may be due to their collection by the vacuum oil used in the sintered collection plates of the ELPI®+. Accounting for the measured volatile chemicals improved the recovery efficiency of the Mini MOUDI™ impactor by 2.9–7.5% with the average recovery efficiency exceeding 82% for the two JUUL ENDS Products. In comparison, accounting for the measured volatile constituents increased the recovery efficiency of the ELPI®+ impactor by 0.4% or less, which did not narrow the recovery efficiency range, that based upon the estimated dilution, consistently exceeded the measured mass loss from both JUUL ENDS products.

Synthesis and properties of oil-filled polycaproamide

The effect of antifriction additives on the process of ε-caprolactam anionic polymerization and on the properties of the synthesized samples has been studied. Motor oil, vacuum oil, household lubricating oil and polymethyl-siloxane fluid were used as antifriction additives. It has been shown that the introduction of antifriction additives at the stage of synthesis of oil-filled polycaproamide reduces the rate of anionic polymerization of ε-caprolactam. The influence of oils on the complex of physico-mechanical, thermal and operational properties has also been studied. It was found that the use of oils at the synthesis stage helps to reduce the coefficient of friction of the samples compared with the control sample. The best effect is observed when using 5 7 wt.% of petroleum oils (a decrease of 50 66% compared to the control sample). The water absorption of oil-filled polycaproamide samples containing petroleum oils is also reduced (by 37% compared to the control sample). At the same time, there is a deterioration in the physical and mechanical properties and an increase in oil and petrol absorption.

Effect of oil pressing and packaging under oxygen-free conditions on yield, oxidative stability, antioxidant activity, and physicochemical characteristics of perilla oil

Perilla seeds for obtaining oils were pressed at vacuum levels of 101.33 (control) and 2.67 kPa using a specially designed vacuum container and packaging device. This work investigates the effect of the presence of oxygen on viscosity, oxidative stability, fatty acid composition, and volatile compounds during a 6-month storage. The acid and peroxide values for the control oil increased by 12.80 and 30.76 fold, respectively, but did not change over time for the perilla oil stored in vacuum. Eight volatile compounds related to oxidation were detected as the control oil became rancid. Some of these compounds were present in small amounts or not at all in the vacuum oil. In conclusion, our results show that oxygen-free pressed oil and packaging are excellent in preserving the physicochemical properties, and oxidative stability in perilla oils.

Comparative Study of Atmosphere Effect on Wood Torrefaction

Climate change, biomass utilization, and bioenergy recovery are among the biggest current global concerns. Wood is considered an environmentally benign material. Nevertheless, it must be processed for desired applications. Upon thermal treatment ranging from 180 °C to 280 °C, under low oxygen concentrations, wood becomes a material with improved dimensional stability, resistance to fungal attacks, grindability, hydrophobicity, and storage stability. Several strategies for wood treatment have been investigated over the course of the past decades, including the use of steam, nitrogen, smoke, vacuum, water, and hot oil. The goal of this work is to investigate the influence of pressure and atmosphere on the torrefaction of poplar. Through a systematic analysis of poplar wood samples treated under reduced pressures and different atmospheres, while keeping the same heating profile, it was possible to establish that changes observed for mass loss, color change, wood composition (via TGA/DTG analysis), functional groups (via FTIR), elemental analysis, and X-ray diffractograms relate directly to known reaction pathways occurring during torrefaction. Changes observed under reduced pressures have been associated with the relative concentration of oxygen in the reaction atmosphere and to the reduced diffusion times experienced by reactive by-products during the treatment. Conversely, extended diffusion times resulted in more significant changes for reactions carried out under N2, water vapor, and air.

Effects of vacuum oil quenching on distortion of 42CrMo Navy C-ring

To better analyse the process parameters effects on distortion, a multi-field coupling simulation of the 42CrMo Navy C-ring vacuum oil quenching process is performed using DEFORM software. The cooling curves of different processes are measured using a stainless-steel probe, and the heat transfer coefficients are calculated by solving the inverse heat conduction problem to accurately predict the transient temperature field. The numerical analysis results demonstrate that increasing the oil temperature rarely affects the distortion. Decreasing the agitation frequency from 50 to 10 Hz can reduce the distortion by 48%. The pressure above the quenching tank has the most effect on distortion, as increasing the pressure from 10 to 50,000 Pa increases the gap by 1.5 times.

High Efficiency Compound Vacuum Oil Gas Separation Technology Based on Integrated Oil Filter of Ultra-High Voltage Transformer

In order to improve the filtering effect of vacuum oil purifier, the author proposes the research and application of high-efficiency compound vacuum oil-gas separation technology based on electric ultra-high voltage transformer integrated oil purifier. The author studies under the condition of constant oil temperature and flow rate, the effect of vacuum degree on the filtering effect of transformer oil vacuum oil filter. Using the research results, a frequency conversion automatic vacuum oil filter is designed, which makes the processing process have the characteristics of simple operation, high degree of automation, and high work efficiency. The test results show that if the transformer oil processed by the variable frequency automatic vacuum oil purifier is new oil, its water content is less than 45 mg/kg and the gas content is less than 12%; when the breakdown voltage is greater than 25 kV, the transformer oil index can meet the following requirements after the equipment is filtered for one cycle: breakdown voltage ≥75 kV; water content ≤5 mg/kg; and gas content ≤0.1% (volume ratio). After one cycle (after 100 min), the variable frequency automatic (three-stage) vacuum oil filter can greatly shorten the time of transformer oil circulating and filtering. Conclusion. The designed frequency conversion automatic vacuum oil purifier is obviously better than other transformer oil vacuum oil purifiers.

Quality assessment of ready‐to‐eat Pacific saury (Cololabis saira) using microwave‐assisted thermal sterilisation combined with olive oil vacuum impregnation

SummaryAlthough microwave‐assisted thermal sterilisation (MATS) held great potential to sterilise ready‐to‐eat (RTE) products compared with traditional retort sterilisation, the quality improvement effect of MATS treatment on shelf‐stable RTE products has not been extensively studied. This study was performed to evaluate the efficacy and applicability of MATS combined with olive oil vacuum impregnation against lipid oxidation and microbial growth in RTE Pacific saury during storage. MATS combined with olive oil vacuum impregnation (MTSO) effectively reduced processing time (by 57%) compared to retort‐treated RTE Pacific saury at the same thermal lethality value. The lower cooking loss (6.19%) and colour damage indicated that MTSO enhanced water retention and the stability of tissue structure compared to retort‐treated group (9.88%) or no olive oil group (7.11%). Lipid oxidation and protein degradation were effectively inhibited in MATS groups compared to retort‐treated ones during storage; such effect was more effective in olive oil impregnated group. Likewise, microbial activity and electronic sensory evaluations showed that the shelf life of MTSO group was extended by 1 week compared to retort‐treated groups. Overall, MTSO had considerable industrial potential to yield RET Pacific saury and even RTE products with better quality attributes than retort‐treated ones.

Reducing environmental hazards in the elimination of oil spills through the use of sorption materials based on polyurethane foams containing waste from agricultural and polymer industries

The work is devoted to the development of a sorption material based on elastic polyurethane foam (PUF) containing waste from agricultural and polymer industries. The fillers were fruit shells of buckwheat grains, rice, acacia sawdust, fruit shells, rice straw, walnut shells and ground corn cobs, hardwood sawdust, polymeric waste of expanded polystyrene foam. Oil from the Romashkinskoye field (Tatarstan) was used as a pollutant. The optimal mass ratio of the components of the material A of the PPU component: B of the PPU component: filler = 1: 0.6: 0.16-0.72 (depending on the type of filler) has been determined. The best absorbing capacity of ∼ 13 g / g is possessed by a material based on polyurethane foam and rice straw. Sorption material for cleaning aquatic ecosystems has a high absorbing capacity not only for petroleum products (diesel fuel, industrial oil), but also for products of inorganic origin (vacuum oil). The sorption material is selective and has a higher absorption capacity with respect to oil than to water, the coefficient of selectivity of absorption is 0.4 for an exposure time of 120 min. The possibility of utilization of waste sorption material by the method of thermochemical degradation using a destructive agent based on PPU component A was investigated. The resulting destructate is a homogeneous liquid, easily combined with BND 60/90 bitumen with the formation of a homogeneous polymer-bitumen binder.

Thrust characteristics of compact high-voltage pulsed plasma thruster utilizing liquid propellant

In this work, we present the results on thrust performance of 0.5 kg sub-joule pulsed plasma thruster prototype based on a high-voltage transformer with magnetic storage capable of work at frequency of 400 Hz. The discharge unit is made of ferroelectric ceramics with an option for utilizing liquid propellant. In case of vacuum oil as a propellant, we obtained values of thrust of ~ 80 nN·s per discharge and 33 μN·s for 400 pulses in 1 second.

Dielectric Engineering Boosts the Efficiency of Carbon Nanotube Photodiodes.

Carbon nanotube (CNT) photodiodes are a promising system for high-efficiency photocurrent generation due to the strong Coulomb interactions that can drive carrier multiplication. If the Coulomb interactions are too strong, however, exciton formation can hamper photocurrent generation. Here, we explore, experimentally and theoretically, the effect of the environmental dielectric constant (εenv) on the photocurrent generation process in CNTs. We study individual ultraclean CNTs of known chiral index in a vacuum or dry nitrogen gas (εenv = 1) and oil (εenv = 2.15). The efficiency of photocurrent generation improves by more than an order of magnitude in oil. Two mechanisms explain this improvement. First, the refractive index of the environment optimizes the interference between incident and reflected light. Second, exciton binding energies are reduced in oil, changing the relaxation pathways of photoexcited carriers. We varied the axial electric field in the pn junction from 4 to 14 V/μm. Our measurements at high field indicate that autoionization of second-subband excitons can coexist with carrier multiplication. Dielectric screening makes this coexistence regime more accessible and allows us to reach photocurrent quantum yields greater than 100%.