Vacuum Pump Research Articles

Operation of 2 K cryogenic system with cold compressors for the SHINE test facility

The Shanghai high repetition rate X-ray free electron laser (XFEL) and extreme light facility (SHINE), a quasi-continuous wave hard XFEL facility, is currently under construction. In order to test all the superconducting components, assembled cryomodules and undulators, the SHINE test facility that consists of various test benches has been built. A superfluid cryoplant with 1 kW@2K was installed, commissioned, acceptance tested and turned into operation to support the cryogenic tests. The plant consists not only of a standard compressor system and cold box but also of a process vacuum system for 2 K operation. In the 2 K cryogenic system, three-stage cold compressors are firstly used to compress helium vapor at a mass flow of up to 50 g/s from 28 mbar to about 400 mbar. Afterwards, the sub-atmospheric helium is continually pressurize to the suction pressure of the warm compressors by five parallel process vacuum pumps. During the first eight months of 2 K operations, the tuning of the cold compressor regulation has been implemented to adapt the different static and dynamic heat loads. A helium pressure stability of superconducting cavities better than ±0.15 mbar at 31 mbar was achieved inside the vertical test bench with additional heating power of 160 W. In this paper, the pump down procedure and the operation results of cryogenic system at 2 K will be described.

Multi-objective Optimization of Injection Molding Process Based on One-Dimensional Convolutional Neural Network and the Non-dominated Sorting Genetic Algorithm II

<div>In the process of injection molding, the vacuum pump rear housing is prone to warping deformation and volume shrinkage, which affects its sealing performance. The main reason is the improper control of the injection process and the large flat structure of the vacuum pump rear housing, which does not meet its production and assembly requirements (the warpage deformation should be controlled within 1.1 mm and the volume shrinkage within 10%). To address this issue, this study initially utilized orthogonal experiments to obtain training samples and conducted a preliminary analysis using gray relational analysis. Subsequently, a predictive model was established based on a one-dimensional convolutional neural network (1D CNN). Input parameters from the injection molding process, including melt temperature, mold temperature, packing pressure, packing time, injection pressure, injection time, and cooling time, were used while warping deformation and volume shrinkage were considered as outputs. Global optimization was performed using the non-dominated sorting genetic algorithm II (NSGA-II), and the optimal combination of process parameters was evaluated using the criterion importance through intercriteria correlation—technique for order preference by similarity to ideal solution (CRITIC-TOPSIS). Moldflow analysis demonstrated that the obtained indicators outperformed the optimization results from orthogonal experiments, confirming the effectiveness of the injection molding process parameter optimization method based on 1D CNN-NSGA-II. In comparison to the pre-optimization results, product warping deformation decreased by 40.68%, and volume shrinkage reduced by 18.14%, and all of them meet the production requirements.</div>

HYKYHT: A versatile, affordable, and open-source 3D-printed liquid aspiration system

This paper aims to provide the details for making affordable single and multichannel liquid aspirators for wet labs. A liquid aspirator is a basic laboratory device that can cost several hundred Euros. We present a < €25 3D print solution that performs equally well in daily lab routines and is compatible with various vacuum sources, including an aquarium pump or household vacuum cleaner. Presently, commercial aspirators cost more than a decent entry-level 3D printer capable of producing all the parts listed in this manuscript. The models were designed with Tinkercad, with easy printing and minimal support in mind. The versatility and the ultra-low-cost solution we presented could ease the daily workflow of researchers in various research fields. Furthermore, it is valuable to high school or undergraduate student labs and community wet labs for science enthusiasts, where funding is generally limited.

Novel Natural Vacuum Membrane Distillation for water desalination: A combinational approach

Many methods have been proposed to produce fresh water utilizing solar and low-grade energy. The natural vacuum method is widely used despite its limitations in water production. The entry of non-condensable gases into the condenser reduces the amount of water production in the natural vacuum system. In addition, it requires a large evaporator surface to produce fresh water at a high rate. This research resolves these limitations for the first time by integrating the natural vacuum and membrane distillation methods, increasing the evaporation area in a small space, and creating a re-vacuum. Based on the results, the amount of water production for feed water with a salinity of 0.5 M, a flow rate of 60 L/h, and temperatures of 45, 65, and 85 °C reach 5.5, 18.5, and 45.9 m3/day for each square meter of the membrane by combining the methods above without creating a re-vacuum for 24-hour tests. Re-vacuum occurs in this novel system by pumping the saline water upward against the outlet valve and the existing membrane. When a re-vacuum occurs every 6 h, the amount of water production for feed water temperatures of 45, 65, and 85 °C increases approximately by 70 % for all feed water temperatures. However, energy consumption does not rise significantly due to employing a pump instead of a vacuum pump.

The benefits of performing temporomandibular joint arthrocentesis with catheters and a vacuum pump: A randomized control trial

This study aims to compare the effectiveness of two different techniques of double puncture arthrocentesis with and without the addition of catheters and a vacuum pump for management of temporomandibular joint (TMJ) disc displacement without reduction (DDWOR). A total of 48 patients with DDWOR were randomly and blindly allocated into two treatment groups (N = 24): Group 1, TMJ arthrocentesis with the addition of catheters and a vacuum pump to the second needle; Group 2, TMJ arthrocentesis without any addition device. The following variables were registered and compared between groups: patient's pain perception (visual analogue scale [VAS; 0–10]); maximal interincisal distance [MID; mm]; joint effusion (JE, presence or absence); facial edema (FE; presence or absence); and the operation duration (OP; minutes). Patients in Group 1 presented with significantly lower VAS scores (p < 0.001) and presence of FE (p = 0.03) in the post-operative period, also an increase in MID values (p = 0.026), and a reduction in JE (p = 0.022) after 3 months. Besides that, in this group, the procedure was performed significantly faster (p < 0.001). Performing arthrocentesis with the addition of a vacuum pump makes the procedure faster and yields better results in terms of pain, facial swelling, mouth opening and joint effusion.

Sediment-associated microplastics in Chilika lake, India: Highlighting their prevalence, polymer types, possible sources, and ecological risks

The primary objective of this research was to assess microplastics (MPs) in the sediments of Chilika lake. MPs were extracted from 22 sediment samples using the density separation method combined with vacuum pump filtration. A stereo-zoom microscope and Raman spectroscopy were employed to identify the sediment-associated MPs. The total MPs collected from all 22 sites was 440 ± 3.53 particles kg−1 wet sediments, with sizes ranging between 50 and 500 μm. In terms of morphology, fibers and fragments emerged as the dominant MP types, with counts of 210 ± 1.66 and 175 ± 1.76 particles kg−1 wet sediments, respectively. Raman spectroscopy verified the presence of various MP polymers in the sediments, predominantly HDPE (37 %), followed by PS (20 %), PET (18 %), PA (11 %), PP (7 %), and PC (7 %). A notable color variation was observed in MPs; black being the most prevalent (38.8 %), succeeded by blue (19.5 %), green (11.8 %), white (11.5 %), red (10.6 %), and transparent (7.5 %). ANOVA results indicated significant (p > 0.05) variations in MP abundance across the 22 sampling locations. However, principal component analysis (PCA) and multiple regression analysis indicated that water quality parameters did not significantly influence MP abundance, yet it was found that MP retention was higher in fine-grained sediments like clay and silt. The leading sources of MPs in Chilika lake were found to be aquafarming, trailed by river and sewage discharges, fishing activities, antifouling coatings and tourism. Additionally, the pollution load index (PLI) was employed to gauge the ecological risks, categorizing the lake under risk category 1, which implies a minimal level of MPs pollution. This research aims to serve as an early warning system for MPs pollution in productive brackish water habitats globally, including Chilika lake, guiding policymakers towards appropriate management strategies and preventive measures.

Аналіз конструкцій глушників вакуумних насосів

The substantiation of the structural and functional scheme of the muffler filter of the rotary vane vacuum pump, which has the ability to separate oil from air and collect it for further processing, has been completed. The proposed design, due to its design feature, provides sound suppression, reduces noise and has minimal resistance to the movement of the air flow in the middle of the muffler filter. The muffler filter is based on the fact that air, together with the oil that lubricates the vacuum pump nodes, enters the muffler filter through the inlet pipe at a speed of 11...16 m/s, which allows the most complete separation of oil from air. The trajectory of the movement of air in the muffler is described by a helical winding, and therefore, centrifugal force acts on the oil particles in a suspended state, as a result of which the oil particles are thrown to the sieve catcher, the oil is separated from the air and enters the interwall space of the housing and the sieve catcher, and flows down into the oil sump, from where it is drained using a tap. After that, it can be sent for processing, or, after cleaning, enter the pump lubrication system. The oil-free air continues to move over the surface of the screw winding, and due to the change in the pitch of the screw winding, the air decreases its speed, as a result of which the noise level decreases and oil content is cleaned more efficiently. Air passes to the top cover and enters the environment through the outlet pipe. The work establishes a relationship between the pump performance and the design parameters of the muffler filter. In production conditions, it was investigated that the separation of oil from air in the proposed muffler is 93-95%, and the amount of noise reduction is 15-22 dB. The use of a muffler filter implies a decrease in the productivity of the vacuum pump, which is about 1 m3/h, compared to the serial one - 1.28 m3/h. To introduce the muffler filter into production, it is advisable to use the relationship between the performance of the vacuum pump and the structural parameters of the muffler filter and to develop a division into standard sizes.

An investigative study on different magnetic ionic liquids to be used as a lubricant and sealant in a vacuum pump

The aim of this work is to explore the possibility of using a magnetic ionic liquid as both a lubricant and sealant in a vacuum pump. The current lubricant in use is due to become obsolete due to incoming legislation on fluorinated compounds. The long-term goal is to use a magnetic field to hold the novel lubricant in place to create a better seal and thus reduce pressure more effectively whilst also lubricating the necessary mechanical parts. This paper explores physical properties (contact angle, viscosity, coefficient of friction (COF) and magnetism) and chemical properties (thermal stability and chemical stability as deduced by X-ray photoelectron spectroscopy (XPS)) of three ionic liquids based on imidazolium cations with varying length of alkyl side chain and a tetrachloroferrate anion along with two control lubricants which are used currently in the field and based upon perfluoropolyether (PFPE). The work shows that the three magnetic ionic liquids possess a lower COF value than the two control lubricants when measured using a Bruker UMT TriboLab suggesting they may perform better in the real life vacuum pump. Upon analysis of the three ionic liquid samples after tribological testing using XPS, it was shown that the ionic liquid samples displayed minor differences in spectra suggesting good stability with no obvious decomposition or degradation of the sample.

ONE-DIMENSIONAL TRANSIENT MODEL OF FOOD PRODUCT TEMPERATURE AND WEIGHT LOSS EVOLUTION IN A VACUUM COOLER WITH MEMBRANE HUMIDIFICATION

A one-dimensional, transient model was developed to predict the temperature and weight loss evolution of a food product cooled using a vacuum cooling system with membrane humidification. The model included the following: (1) a sub-model based on the mass conservation of air and vapor inside the vacuum chamber; (2) a sub-model based on the coupled mass and heat transfer with inner vapor and heat generation; and (3) a sub-model based on the mass conservation of water vapor along the flow channels inside the humidifier. The vacuum chamber pressure was reduced from 1 atm to 2200 Pa using a vacuum pump with deflating speed of 500 m3/hr and condenser and membrane humidifier operating temperatures of 13&amp;deg;C and 60&amp;deg;C, respectively. A meat joint with a weight of 5.30 kg was cooled from an initial core temperature of 74&amp;deg;C to below 10&amp;deg;C. The conventional and modified models both cooled the food product to 10&amp;deg;C in 25 minutes. It was found out that increasing the chamber relative humidity reduced the surface water evaporation while the internal evaporation rate remained the same. Thus, the meat's moisture content, which was initially at 73.51&amp;#37;, was reduced to only 65.44&amp;#37;-an improvement from the conventional vacuum cooling system's 64.31&amp;#37;. This translated to product weight loss of only 10.98&amp;#37;, which represented significant progress compared to the conventional system's 12.51&amp;#37;. The simulation results indicated that employing humidification in a vacuum cooling system reduces the product total moisture loss while maintaining the rapid cooling rate.

МОДЕЛИРОВАНИЕ ПРОЦЕССОВ ВЛАГОПОГЛОЩЕНИЯ ДРЕВЕСИНЫ ПРИ ИЗМЕНЕНИИ ДАВЛЕНИИ СРЕДЫ

On the basis of differential equations of material balance in a hermetic chamber and heat and mass transfer in the object under study under given boundary conditions, a mathematical model describing technological processes occurring with changes in medium pressure has been developed. The methodology of experimental studies of the process of material saturation in a unit operating in a periodic mode at varying medium pressure is presented. Birch veneer is taken as a model material for experimental studies, the heat and mass transfer characteristics of which are widely known. The preparation of the experiment consisted in the production of samples of the saturated material, in the form of rectangular plates with dimensions of 30 * 90 mm and a thickness of 4 mm. The results of physical and mathematical modeling are reflected in the form of profiles of changes in moisture content and temperature along the cross section of the material during saturation. It is established that the active process of saturation of the veneer with moisture under changing medium pressure is observed during the first 15 minutes, and by this time the temperature in the center of the material exceeds 120 ° C. The results of mathematical modeling were obtained using the Visual Basic for Applications software environment. The discrepancy between the calculated and experimental data does not exceed 15%. The developed mathematical model of the process makes it possible, when the capacities of sources (steam generator) and drains (condenser and vacuum pump) vary, to recommend the modes of conducting the technological process or to select the capacities of the steam generator and pump in accordance with the required law of pressure change in the technological process. For physical modeling of the investigated process in the processing of wood raw materials, an experimental setup was created, on which experimental data confirming the adequacy of the developed model were obtained.

Research on longitudinal dynamics and design of RF parameters of synchrotron for XiPAF-upgrading project

Xi ’an 200 MeV Proton Application Facility (XiPAF) will be upgraded to proton and heavy ion synchrotron recently. In order to ensure the enough life of heavy ion beam, the synchrotron requires ultra-high vacuum, and the designed static vacuum is better than 5×10-10 Pa. In order to place enough vacuum pumps in the synchrotron, the circumference of the synchrotron was increased from 30.9 m to 39.96 m. The revolution frequency range of heavy ions is 0.49∼1.03 MHz. In order to reduce the engineering difficulty and improve the lower limit of frequency bandwidth requirement of the RF system, the harmonic of h=2 is used to capture and accelerate the heavy ions, and the frequency bandwidth range of the RF system is adjusted from 1∼6 MHz to 0.8∼5.0 MHz. In this paper, the longitudinal dynamics parameters of the upgraded synchrotron are designed, and the simulation calculation is carried out. Finally, the parameter requirements of the RF system are proposed.

Effects of combined vacuum and heat pump drying on drying characteristics and physicochemical properties of pineapple

Vacuum drying (VD) and heat pump drying (HPD) are widely used in the food industry. However, their application is limited due to low drying efficiency and the resultant poor quality of dried products. Additionally, varying drying durations in combined drying can markedly impact the physical and chemical properties as well as the nutritional content of the dried product. To achieve the highest quality dried products, VD + HPD was initially compared and identified as the most suitable drying method. This paper investigates the impact of the first stage drying duration on the physical characteristics (color, microstructure, texture, volume shrinkage rate (VSR), rehydration rate (RR)) and bioactive components (total phenolic content (TPC), total flavonoid content (TFC), Polysaccharides) of pineapple. The results indicated that VD + HPD necessitated lower energy consumption and markedly enhanced the physical properties of dried products. The brightness, rehydration rate (RR), color difference, volume shrinkage rate (VSR), and surface microstructure of pineapple dried by VD 5h + HPD 5.5h were all optimal. In comparison with other tested drying methods, the textural properties (hardness, chewiness, viscosity) and bioactive components (TPC, Polysaccharides) exhibited significant improvement. Overall, these results indicate that VD5h + HPD5.5h can be viewed as a valuable technology for improving the quality of dried pineapples.

Influence of voltage unsymmetry on energy characteristics of vacuum pump

Deviation and asymmetry of the voltage have the greatest impact on electric drives of production machines and mechanisms. Voltage asymmetry leads to losses that have an electromagnetic and technological component. Studies on the effect of voltage asymmetry on the technological characteristics of working machines and mechanisms have shown that their productivity decreases with voltage asymmetry. However, there are no studies on the influence of spring asymmetry on the energy characteristics of working machines. The purpose of the research is to determine the influence of voltage asymmetry on the power characteristics of vacuum pumps. With voltage asymmetry, constant and variable losses in an asynchronous electric motor change, which cause an increase in energy losses in an asynchronous electric drive. The energy assessment of the electric drive of the vacuum pump was carried out according to the specific consumption of electricity. The influence of voltage asymmetry on the power characteristics of vacuum pumps was studied. The dependence of the specific power consumption on the change in stiffness of the mechanical characteristics of the electric motor, which is caused by voltage asymmetry, is obtained. It was established that slippage and power loss increase with voltage asymmetry. As a result, the specific loss of electricity in the electric drive of vacuum pumps increases.

The Present Status and Progress of the CHMFL 40 T Hybrid Magnet

The development of new high magnetic field facilities in the Chinese High Magnet Field Laboratory (CHMFL) will soon be completed according to the present situation. For the construction of the 40 T hybrid magnet, which will be the highest magnetic field facility in China, great progress has been achieved so far, for example, the engineering design of the resistive insert composed of six Florida-Bitter-type coils has been completed and part of the Bitter disks has been punched in Shanghai, and significant R & D progress on the design and manufacture of the superconducting outsert has been made, and the other main components of the superconducting outsert, such as?cryostat, 80 K thermal shield, vacuum pumping units, busbars, a pair of 16 kA HTS leads, overpressure protection device and so on, have been manufactured. The recent development of the CHMFL 40 T hybrid magnet is introduced in detail.

Improving the operation process of a vane type vacuum pump for milking machines

Improving the operation process of a vane type vacuum pump for milking machines

Innovative Fabrication of Metal Alloy Structures via Laser-Induced Forward Transfer on Flexible Substrates.

Laser-induced forward transfer is a contactless, nozzle free process which enables accurate, precise and fast development of 3D structures. However, a number of shortcomings such as shockwave generation, poor adhesion to receiver substrates and uniform depositions limit LIFT to be utilized. Therefore, this research tends to put forward easy and effective solutions for successful mitigation of the LIFT limitations. Receiver surface modifications and low-pressure conditions are introduced through laser surface texturing (LST) and a vacuum pump. A number of textures and orientations are investigated for determining the optimal copper (Cu) deposition. Furthermore, utilization of the same laser system for LST enables the manufacturing process cost and time effective. In addition to Cu depositions, additive layers of silver (Ag) and platinum (Pt) are deposited. Finally, Ag and Pt micropillars are fabricated on their respective additive layers leading to formation of Cu-Ag and Cu-Pt alloys structure. Subsequently, electrical and material characterizations are made to validate for potential applications. Experimental evidence shows greater adhesion with electrical properties for LST-based LIFT in low pressure conditions. Finally, an energy analysis is performed based on theoretical and finite element methods (FEM) to gain greater insights into mechanics of the LIFT process.

A Case Study of Peat Ground Improvement by Vacuum Consolidation in Hokkaido, Japan

This paper presents the field performance of vacuum consolidation method on peat ground and some technical learning from the field trial. Peat is well known to be a soft soil which has particular characteristics, including extremely high compressibility and greatly low undrained shear strength. In case of an embankment building over peat ground, sliding failure and large settlement often occur due to the particular characteristics. For actual construction sites on peat ground, therefore, some kinds of ground improvement methods are commonly used. One of the methods is the vacuum consolidation method which can load vacuum pressure with the soft ground by vacuum pumps and prefabricated vertical drains to accelerate the consolidation and increases the strength of soft ground. Peat ground distributed widely in Hokkaido, the northernmost land of Japan. A full-scale trial construction of vacuum consolidation was conducted in a highway project over peat deposit in Hokkaido of Japan to reveal its performance. Although the undrained shear strength of peat ground at the trial construction site was approximately 10 kN/m2 and extremely low, a 10.7 m high embankment was successfully built in only 45 days. This experimental fact implies that the vacuum consolidation method has extremely high effects in improving the stability of peat ground. Based on a result of the trial construction, it also revealed that the increase of undrained shear strength of the peat ground using vacuum consolidation and the suitable spacing of prefabricated vertical drains for peat ground.

Development and evaluation of a vacuum impregnation system for enhancement of biochemical properties of food materials.

Vacuum impregnation is a novel methodology for adding various substances to porous foods. This study aimed to develop a cost effective automate system for vacuum impregnation of food materials to enhance their nutritional, functional and sensory properties dependingon the functionality of the impregnation solution. The developed vacuum impregnation system includes a vacuum chamber, vacuum pump and an automation setup for creating and maintaining vacuum conditions, feeding impregnated solutions to the samples and releasing vacuum. Fresh-cut spinach leaves were impregnated with ascorbic acid (AsA) and calcium chloride (Cacl2) (10% concentration) in the setup in order to test the effect of the process on some biochemical properties. Statistical analysis revealed significant effect of vacuum impregnation on the biochemical properties (total soluble solids, total phenolic content, flavonoid content and free radical scavenging activity) and color of spinach leaves during storage up to 4days. Impregnation process showed significant increase in the total phenolic and flavonoid content of the spinach leaves. Increment up to 78% in antioxidant activity was seen for the uncoated impregnated leaves as compared to 59% activity in untreated samples. Thus, products with desired parameters can be produced with this process with minimal impact on their properties at a lower cost and in a shorter time period.

Negative Pressure Wound Therapy in the Treatment of Sternal Infection after Cardiac Surgery: a Case Report and Literature Review

The aim. To assess the effectiveness of negative pressure wound therapy (NPWT) in the treatment of sternal infection following heart surgery.&#x0D; Materials and methods. During 2019-2022, six patients aged from 46 to 69 years underwent NPWT for sternal infection which occurred within 2 to 24 weeks after complete median sternotomy. For the purpose of temporary wound closure, standard dressing kits with sorption sponge were used. Negative pressure was created by electric vacuum pump with a constant vacuum mode at a range of -75 to -115 mm Hg and a duration of 4-5 days per session. In all cases determination of serum procalcitonin, bacteriological examination of wound discharge, computed tomography (CT) of the chest were performed in dynamics.&#x0D; Results. The study revealed that NPWT in all cases promoted wound cleansing, gradual closing of fistulas and non-grooving pockets, termination of inflammatory process, reduction of the wound cavity, thus accelerating complete wound healing. A significant reduction in the level of wound contamination was revealed after the first NPWT session (below the critical level of 103 CFU), compared to that before treatment (107-108 CFU). Normalization of the level of procalcitonin in the blood serum was determined by day 5-7 of NPWT. CT showed the signs of sternum stability and reduction of inflammatory process in surrounding tissues after treatment. Each treatment case required from 2 to 4 sessions. The duration of hospital stay ranged between 25 and 35 days. A treatment case of one of the 6 patients included in the study is described.&#x0D; Conclusions. NPWT has proven to have positive clinical effect in the local treatment of postoperative sternal infection and can be applied as an ultimate or a transitional option. Methodology of its clinical application needs further elaboration.

Comparative analysis of syringes versus pump devices in benchtop aspiration thrombectomy models: A systematic review and meta-analysis.

Although direct contact aspiration has emerged as one of the leading techniques for mechanical thrombectomy (MT), there is still ongoing debate about the aspiration/suction pump devices that can optimize recanalization rates. To address this gap, we conducted a meta-analysis comparing the aspiration efficacy of 60 ml syringe and pump devices in benchtop MT models. Systematic literature review was conducted using Medline, Embase, Web of Science, and Scopus in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Outcomes of interest included flow rate and vacuum pressure delivered by a 60 ml syringe and several aspiration pumps. We used a random effects model to calculate the mean difference (MD) with 95% confidence intervals (CIs) and a statistically significant difference was considered as a two-sided p-value of less than 0.05. We included six benchtop studies comparing 60 ml syringes and vacuum pumps. Our meta-analysis showed that there were no significant differences in vacuum pressure (MD:0.71inHg, 95% CI: [-0.81;2.23], p = 0.359) and flow rate (MD:0.27 mL/s, 95% CI: [-3,07; 3.61], p = 0.873) between 60 ml syringes and vacuum pumps groups. Our study demonstrated comparable performance in terms of vacuum pressure and flow rates between a 60 ml syringe and a heterogeneous combination of commercially available aspiration pumps.