#forevacuum

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Whitepaper: Leak Detection for Electric Vehicle Battery Production

  Electric vehicles are a decisive factor in reducing CO2 emissions in road traffic. They store the energy required for propulsion in batteries and an electric motor converts it into motion. If the batteries are charged with electricity from renewable energy sources, they even have a completely CO2-free energy balance. Today, lithium-ion batteries are used almost exclusively as accumulators. Vacuum technology is indispensable for their production. This white paper shows how test gas leak detection ensures quality The proper functioning, quality and safety of lithium-ion batteries, which are used as accumulators in electric vehicles, depends on their integrity and impermeability to external influences such as moisture ingress. For this reason, leak detection systems are used in battery production to check the batteries. Pfeiffer Vacuum supplies the necessary vacuum solutions from a single source. You can download the white paper as a PDF here: www.pfeiffer-vacuum.com   Read the full article

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In this way they extend the pressure range of other vacuum pump types or replace mass flow compressors like steam jet vacuum pumps, for example. Roots pumps are available with pumping speeds of up to 15.000 m³/h. Since Roots vacuum pumps are capable of producing only relatively small pressure differences in the medium and rough vacuum range, they are operated together with so-called backing or forevacuum pumps. Depending on the operating point, Roots vacuum pumps are combined, in consideration of the stages, in multi-stage units. Designing and properly rating multi-stage Roots vacuum pump stations in consideration of the ideal backing pump belongs to the main field of activity of the company Arpuma GmbH.

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Research of Hydrogen Absorption-Desorption by Ti-Al-Nb Alloy-Juniper Publishers

Authored by Kurbanbekov ShR                                                                          

Abstract

The paper presents kinetics of hydrogen sorption of Ti-23.5at%Al-21.5at%Nb alloys in isothermal conditions underthe temperature of 450, 500 and 550 °С. It was determined that maximum quantity of absorbed hydrogen is observed at material of sorbed alloy under the temperature of 550 °С. That presents approximately 0.289mass%. It had been found that hydrogen is released under the temperatures within 700 …790 °С. In addition, it was revealed that maximum release of hydrogen composes 85% of samples saturated under the temperature of 550 °С.

Keywords: Intermetallic compound; Absorption-desorption; Hydrogen; Plasticity; Crucible

    Introduction

As is known, to find a safe method for reversible hydrogen storage is currently one of the important issues in the field of hydrogen energetics. Storage of the hydrogen in various hydrides of metals and alloys is one of the advanced methods to solve this issue [1]. Application of alloys for hydrogen storage and its use depends on several tasks, which focused on increasing of sorption properties and cyclic stability of alloys. Ti-Al alloys are one of the efficient materials for storage of hydrogen [2,3]. Using of alloys to storage hydrogen and its use depends on several tasks, which are to increase the sorption properties and cyclic stability of alloys. Alloys based on Ti-Al are one of the most effective materials for hydrogen storage [2,3]. It is known that, additional introduction of niobium into the Ti-Al system significantly increases the plasticity of Ti3Al, intermetallic which can be explained by a decrease in the degree of ordering and decrease in the share of covalent bond [4]. Also, additional introduction of niobium into the Ti-Al system [5,6] leads to an increase in its absorption-desorption properties of hydrogen due to the formation of nanoscale phases having less dense packaging compared to the face centered close-packed lattice of Ti3Al.

The purpose of this paper is to determine the optimal absorption-desorption temperatures of hydrogen to the sample materials based on Ti-Al-Nb system and to study the changes in its structural-phase state.

    Materials and Methods of Research

Ti (99.9%), Nb (99.96%) and Al (99.98) powders were used as initial raw materials for producing Ti-Al-Nb-composite.

Technology of sparkplasma sintering (SPS-technology) of powder mixtures was used to create compact samples based on intermetallic Ti-Al-Nb system. Sintering of powder mixtures was conducted on a special facility Labox-1575. Research of hydrogen sorption kinetics by intermetallic compounds of Ti-23.5at%Al-21at%Nb system was conducted on an experimental facility VIKA [7] under the temperatures of 450, 500 and 550°С. The facility consists of a working chamber, pumping system and information-measuring system (IMS). Differential pumping system including forevacuum pump NVR-5DM with a nitrogen trap and two magnetic discharge pumps NORD-100 and NORD-250 was used to ensure the required pressure in the working chamber of the facility. Forevacuum pump is used to pre-pumping of gases from the working chamber after loading the sample into the crucible, magnetic discharge pump NORD-250 is used for pumping the working chamber and the measuring path in the annealing process after loading samples, the pump NORD-100 is used to create high vacuum in the chamber and the measuring part of the experimental facility during the experiment. The experiments consisted the following: Ti-23.5at%Al-21at. %Nb sample was loaded in a special ampoule device (AD). After loading of the sample, the high–temperature decontamination of AD cell with the samples was conducted for 30 minutes at a temperature of 800-850°C and a constant pumping of the AD volume by a turbomolecular pump were conducted. Then the body of the AD experimental cell was cooled down to the studied temperature (the temperature of hydrogen saturation) and spectrally pure hydrogen was injected with samples to a given pressure in the volume of AD. Further, pressure change in the AD volume with studied samples was recorded under the preset saturation temperature using a deformation pressure sensor. After that, the heating of ampoule device with samples was stopped, and the samples were cooled in the hydrogen atmosphere to room temperature. After 12 hours, samples were heated again to a preset saturation temperature and kept under this temperature shelf for 15-20 minutes, after which samples were cooled to room temperature, and remaining hydrogen was pumped from the volume of the ampoule device.

    Research Results and Discussion

The main criteria that determine the prospects of application of those or other materials for storing hydrogen, typically consider the amount of their sorption capacity, operating temperature and pressure, kinetics of the interaction [8]. Сurves of hydrogen sorption by Ti-23.5at.%Al-21at%Nb alloy under temperatures of 450, 500 and 550°C and a pressure of 41 Torr (Figure 1) were presented to compare processes of sorption isotherms. Figure shows that under the increase of temperature from 450°C to 550 °C, an increase in the rate of hydrogen sorption occurs and respectively, the change in pressure of the ampoule (Figure 1a) is observed. Figure 1b shows the mass fraction of hydrogen absorbed by the sorbent at temperatures of 450-550 °C.Figure 1b shows that there is an intensive absorption of hydrogen at a temperature of 550 °C, the proportion of hydrogen absorption reaches up to 0.289 mass.%. Probably, the interaction of Ti2AlNb phases with hydrogen occurs firstly, traces of which are present in the samples, thus the activation barrier of the reaction of the material main phases is decreased.

The ampoule device was annealed at a temperature of 900 °C for 30 minutes, before the experiment of desorption with an empty ampoule device. Argon was injected to one atmosphere after walls of the ampoule device cooled to a temperature of 20 °C in the volume of the ampoule device, then the ampoule device was closed, and the ampoule volume was pumped to a pressure of 10-4Torr, after which the ampoule device was tested for tightness using RGA-100 quadrupole mass spectrometer and the helium. Further, the desorption process of hydrogen by Ti- 23.5at%Al-21at%Nb alloy was conducted. The heating was from 20 to 790 °C.

In the result of conducted experiments, the dependence of the hydrogen pressure from the sample temperature at an increase up to 790 °C (Figure 2) was obtained. Results of the study of Ti-23.5at%Al-21at%Nb alloy desorption showed that hydrogen release was observed in the temperature range of 700 ... 790 °C. Maximum hydrogen content in the sample saturated at 550 °C was 0.289 mass.%. Figure 2b shows that the hydrogen release from a sample saturated at a temperature of 550 °C reaches up to 85%.The active yield of hydrogen is observed at a temperature of 750 °C.

The paper [9] presents the dependence of the desorption pressure for some systems, which shows that hydrides based on alloys of intermetallic compounds can be used to accumulate hydrogen in a fairly wide range of temperatures and pressures. The main factor limiting the rate of hydrogen release and absorption by the accumulator, in most practically important cases, is the heat and mass transfer in the layers of intermetallic particles, and not the sorption-desorption kinetics on individual particles [10].

The results of the study of hydrogen-adsorption properties showed, that the pressure of hydrogen desorption increases sharply at 500 °C. Thus, Ti-23.5at%Al-21at%Nb alloy is a high temperature getter. Results of the study of hydrogen desorption are presented in Table 1.

Thus, it was found that the rate of sorption/desorption of hydrogen depends on the heating temperature. It is also important to note that the orthorhombic phase of Ti2AlNb is a well hydrogen absorber. This is confirmed by the absorption of hydrogen at a sufficiently low pressure (about 45 Torr.), and can be explained by the acceleration of diffusion in the Ti-Al system by doped Nb.

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Ceramic coating deposition by electron beam evaporation

Publication date: 25 September 2017 Source:Surface and Coatings Technology, Volume 325 Author(s): E.M. Oks, A.V. Tyunkov, Yu.G. Yushkov, D.B. Zolotukhin We describe a new method for the deposition of protective ceramic-based coatings. The novelty of the method lies in the unique interaction of the electron beam with a dielectric target, in which ions in the beam-produced plasma neutralize the target surface charge build-up. This effect is brought about by the use of our novel forevacuum-pressure, plasma-cathode electron beam source, which can produce energetic, focused electron beams, with associated beam-produced plasmas, in the previously inaccessible pressure range of 1–100Pa. The work described here demonstrates the evaporation of aluminum oxide ceramic by electron beam bombardment and the subsequent deposition of an alumina coating. A significant increase in the microhardness of the ceramic-coated Ti substrate and a uniform depth-distribution of the elemental composition has been determined. The approach described here opens up new opportunities for the deposition of coatings in various fields of industry. Read more from Journal of Safety Research http://ift.tt/2t1k0t7

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New rotary vane vacuum pump offers energy savings by up to 25%

  The new R5 RA 0520 A The proven R5 RA from Busch now comes in an improved version with a completely redesigned interior. The new vacuum pump is – acc. to an information of the manufacturer – “25 % more energy efficient than its predecessor, thanks to the optimized compression ratio, pump stage dimensions, and oil discharge path.” It is also available with the company’s variable speed drive, that enables the pumping speed to be adapted to the exact requirements of any process. “As a result, additional energy savings of up to 50 % and a 20 % increase in pumping speed can be achieved. The accessory extends the supply voltage range supported by the vacuum pump, making it suitable for use in almost all countries around the world. This compact and cost-effective solution is also available as a retrofit.” “Compared to the previous generation, the R5 RA 0520 A has a 20 % smaller footprint, is 25 % lower in height, and the absence of external piping improves leak tightness. The compact and hygienic design features surfaces that repel water and dirt. The total number of spare parts has been reduced by 40 %, making maintenance fast and efficient, with all service-related parts located on one side. Heat emissions have also been decreased through an improved cooling system that combines optimal pump operating temperature with compact construction.” The new vacuum pump is made for continuous operation in the rough vacuum range with vacuum levels down to 0.1 hPa (mbar). The pumps are suitable for various applications in vacuum packaging, food and plastics processing, and many other industries. www.buschvacuum.com Read the full article

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Leybold launches Vacuum Calculation and Simulation Tools

  Pump Finder and Leycalc as a calculation tool are web-based tools, users can select and build their vacuum solutions online. The Pump Finder is designed to navigate vacuum users step-by-step to find the ideal pump for their application. Throughout the selection tool, pumps can be refined by entering values for chamber size, target pressure and pipe dimensions. There are two calculation options for modelling different vacuum applications: process flow and vacuum chamber pump down. A process gas flow is a continuous gas flow where the constant pressure is conveyed. A vacuum chamber pump down is an application where the chamber is pumped/evacuated to a specific target pressure. The result is a selection of vacuum pumps that meet the customer's requirements.

Leycalc can be used for detailed engineering of vacuum systems using the same powerful algorithms as Leybold’s application experts. The tool allows customers to calculate their vacuum systems fully independently and for complex scenarios, the experts offer their full support. "Previously, we had to adjust parameters such as chamber size, process gases, cycle times, pipe length and pressure values during the initial contact with the customer. With the help of the simulation software, the user can independently calculate configurations and get an initial idea of the vacuum performance," explains Dr. Tom Kammermeier, Global Application Manager, Industrial Vacuum. "In the past, there were often lengthy dialogues about such details," says Kammermeier. “Now users can perform their calculations independently – with the result that the entire process leads to a more targeted and faster selection of the right solutions for the application. We expect Leycalc to improve the contact quality with our customers." https://calc.leybold.com/en/lp Read the full article

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Technical paper: Vacuum technology in the chemical industry for producing Polyurethanes and Polyisocyanates

  The chemical industry is a supplier of indispensable raw materials for many industries. Not only the automotive and engineering industries, for example, but also the plastics, food, glass and building material industries rely on basic chemicals produced by the chemical industry. By far the most important role is played by polyurethane plastics or resins, which serve as the basis for foams or paints. These substances are employed in countless finished products that we use on a daily basis. Vacuum technology is indispensable for a large part of these applications. For the production of high-quality foams, it requires medium vacuum conditions up to 0.05 hPa Polyurethanes are compounds which are formed in a polyaddition reaction from multiple alcohols (di-, tri- or polyols) and polyisocyanates. Depending on the basic components used, thermosetting plastics, thermoplastics or elastomers are obtained which differ greatly in their properties and can accordingly be used in a large number of different end products. In the EU alone, more than 2 million tons of polyurethanes are produced annually; global demand rises on average by 5 % per year. Polyisocyanates are highly reactive organic compounds and act as crosslinkers for two-component polyurethane, from which coatings and foams are formed. The targeted curing of the substance at room temperature and the use of a special coating device, allow to customize the curing time for the application. For example, in a production plant, coatings only need to be mixed if needed immediately. Vacuum technology is enormously important for the polyisocyanate production. Following the actual production of the isocyanate, the highest possible concentration is ensured by means of a multi-stage distillation process. It requires fine vacuum conditions, i.e., absolute pressures in the range of 0.05 hPa.  ATEX certified vacuum solutions for the production of polyisocyanates TDI (2,4-toluene diisocyanate), which besides MDI (methylene diphenyl di-isocyanate) is the most widely-produced polyisocyanate in the world, is not only a very toxic liquid, but can also be used at higher temperatures to form flammable vapor- air mixtures. For this reason, the operators of the systems preferably use vacuum pumping stations which are certified in accordance with the ATEX Directive 2014/34/EU and which also meet particularly stringent requirements for tightness. In order to cover all aspects of quality and safety in the process operation, exact configuration according to the specific requirements of the respective application is necessary. In the first step, the respective gas volume flows are calculated on the basis of substance data and flows in the process. The results then serve as parameters for selecting the appropriate vacuum pumps. Important requirements include, besides safety, the durability and reliability of the vacuum technology used. Pfeiffer Vacuum offers complete ATEX-certified vacuum systems for the production of polyisocyanates. Most processes require a multi-stage construction of the vacuum system. The Pfeiffer Vacuum experts developed a six-stage system for a large German chemical company consisting of a five-stage Roots and a liquid ring vacuum pump. At different stages of the process, different gas inflows are taken into consideration. The system was created according to the customer’s specifications and fulfilled all individual parameters. CombiLine vacuum pumping stations To enable companies to create the vacuum conditions required in the various applications effectively and in a cost-optimized manner, Pfeiffer Vacuum offers customized solutions based on its comprehensive range of products. Especially with regard to applications in the chemical industry that require a pressure of less than 30 hPa, the Roots pumping stations from Pfeiffer Vacuum’s CombiLine WS have established as solutions. Depending on the required pumping speed and working pressure, different types and quantities of pumps can be installed in the individual pumping stages. Rotary vane, screw, liquid ring and gas-cooled Roots pumps are primarily available as backing pumps. Roots pumps are usually used for additional stages, which are available as air-cooled (standard) or gas recirculated versions and in various materials (e.g., spheroidal graphite cast iron or stainless steel). Specific coatings and coupling types are also available and can be combined for individual requirements. For applications in potentially explosive atmospheres, ATEX-certified 2G and 3G Roots pumps are available.

OktaLine ATEX Roots pump for use in potentially explosive environments ATEX-certified Roots pumps Thanks to their magnetic coupling, the OktaLine pumps are ATEX hermetically sealed. Their extremely low leakage rate of In addition to the advantages already mentioned, the magnetic coupling eliminates the shaft seals. Pumps with shaft seals can heat up due to lack of oil lubrication through friction and therefore represent a potential source of ignition. Experience from the field has shown that this condition – an empty oil tank for lubrication of the shaft seals – is very common. Furthermore, shaft seals are weak points in pressure surges and require regular maintenance.

Magnetic coupling of a Roots pump The OktaLine ATEX has long maintenance intervals resulting in lower maintenance costs. The magnetic coupling also reduces power consumption due to the virtually lossless transfer of the engine torque. As a result, the power consumption at the operating point can be reduced by up to 20 %. This is realized in comparison with other magnetically coupled pumps by a non-metallic containment shell, which has a significantly lower turbulent flow induction than, for example, magnetically-coupled liquid ring pumps. Air cooling also requires considerably less energy than water cooling, which significantly reduces operating costs. A non-blocked overflow valve makes pump replacement and operation very easy. In some cases, retro-fitting a frequency converter was not possible, especially in all applications where the ATEX-certified Roots pump should replace a previously used standard version. Moreover, if there are no additional pressure gauges, then starting the pump at a defined counter-pressure is not possible either. Standard pumps can easily be replaced by new ATEX pumps with its unblocked overflow valve. Neither frequency converters nor pressure monitoring devices need to be installed. Once again, the Roots pump can be started at the same time as the backing pump, so that the new overflow valve ensures not only safe operation but also shorter evacuation times. If the ATEX overflow valve is used in addition to a frequency converter, it ensures faultless operation even in the event of inverter failure. Frequency-controlled drives are suitable for increasing efficiency. This ensures that the system always works in optimum operating condition. Energy costs are saved – "vacuum on demand" becomes possible. Although it is now easier to replace older devices. Experience shows that even small changes made in the course of time in the process flow may necessitate a new consideration. One way of doing this is to optimize the gradation of the Roots pump and the backing pump, allowing better distribution of loads and temperatures. This results in an extension of the run-time. From conception to implementation, the experts at Pfeiffer Vacuum develop individual solutions together with customers from all different areas of the chemical industry. Read the full article