Super High Pressure Research Articles

Thermal Stress Distribution in Thick Wall Cylinder Under Thermal Shock

This paper presented the stress distribution in a thick walled cylinder under thermal shock. Dirac function was introduced to model thermal shock. An analytical solution of the temperature field was obtained by Laplace transform. Based on the temperature solution, the thermal stress response of the thick walled cylinder was solved. The time dependent variations of the temperature field—thermal stress field—were discussed, and the effect of cylinder radius ratio on the problem was given. The exploration in this paper will lay a theoretical reference to further study on the decrease in fatigue damage of the superhigh pressure tubular reactor under thermal shock.

Development of New Fields by Simple High-Pressure Equipment

Such as high pressure machine, it has image difficult to use and dangerous in generally, dose not gain in popularity. In particular over 100 MPa, that is the filed of super high-pressure, there were still many researches carried out on the super high-pressure, however there were few products that is commodification in the world. In this paper, developing machine is easy to use the super high-pressure and technology is utilized super high-pressure of the versatility, therefore commodification shows several possible of super high-pressure.

Design and research on a variable ballast system for deep-sea manned submersibles

Variable ballast systems are necessary for manned submersibles to adjust their buoyancy. In this paper, the design of a variable ballast system for a manned submersible is described. The variable ballast system uses a super high pressure hydraulic seawater system. A super high pressure seawater pump and a deep-sea brushless DC motor are used to pump seawater into or from the variable ballast tank, increasing or decreasing the weight of the manned submersible. A magnetostrictive linear displacement transducer can detect the seawater level in the variable ballast tank. Some seawater valves are used to control pumping direction and control on-off states. The design and testing procedure for the valves is described. Finally, the future development of variable ballast systems and seawater hydraulic systems is projected.

Research on Sintering Stability of Cubic Silicon Nitride Synthesized by Shock-wave

Silicon nitride ceramics was prepared by super-high pressure using theγ-Si_3N_4 powders synthesized by the shock-wave technique as raw materials and with Y_2O_3-Al_2O_3-La_2O_3 mixtures as additives at 5.7GPa from 1370K to 1670K.The stability,relative density,mechanical properties and microstructure of the compacts synthesized at different temperatures were investigated.The results show thatγ-Si_3N_4 is completely transformed toβ-Si_3N_4 at temperature from 1420K to 1670K,and partly transformed toβ-Si_3N_4 at 1370K.Micro-analysis indicates that the typical microstructure of sintered Si_3N_4 is mainly composed ofβ-Si_3N_4 rod crystals with disordered orientation and uniform microstructures.The relative density and Vickers hardness in the as-sintered (5.TGPa,1370K) samples are 98.83% and 21.09GPa,respectively.

Treating high-mercury-containing lamps using full-scale thermal desorption technology

The mercury content in high-mercury-containing lamps are always between 400 mg/kg and 200,000 mg/kg. This concentration is much higher than the 260 mg/kg lower boundary recommended for the thermal desorption process suggested by the US Resource Conservation and Recovery Act. According to a Taiwan EPA survey, about 4,833,000 cold cathode fluorescent lamps (CCFLs), 486,000 ultraviolet lamps and 25,000 super high pressure mercury lamps (SHPs) have been disposed of in the industrial waste treatment system, producing 80, 92 and 9 kg-mercury/year through domestic treatment, offshore treatment and air emissions, respectively. To deal with this problem we set up a full-scale thermal desorption process to treat and recover the mercury from SHPs, fluorescent tube tailpipes, fluorescent tubes containing mercury-fluorescent powder, and CCFLs containing mercury-fluorescent powder and monitor the use of different pre-heating temperatures and desorption times. The experimental results reveal that the average thermal desorption efficiency of SHPs and fluorescent tube tailpipe were both 99.95%, while the average thermal desorption efficiencies of fluorescent tubes containing mercury-fluorescent powder were between 97% and 99%. In addition, a thermal desorption efficiency of only 69.37–93.39% was obtained after treating the CCFLs containing mercury-fluorescent powder. These differences in thermal desorption efficiency might be due to the complexity of the mercury compounds contained in the lamps. In general, the thermal desorption efficiency of lamps containing mercury-complex compounds increased with higher temperatures.

超高圧加工技術で実現する新たな世界(食を支える技術,<メカライフ特集>食をつくる)

超高圧加工技術で実現する新たな世界(食を支える技術,<メカライフ特集>食をつくる)

超高圧水銀ランプの「ちらつき」抑制波形の検討

超高圧水銀ランプの「ちらつき」抑制波形の検討

Influence of Plural Loads on Rupture of the Sealed Parts in Super High Pressure Mercury Discharge Lamps

Influence of Plural Loads on Rupture of the Sealed Parts in Super High Pressure Mercury Discharge Lamps

Liquid Crystal Alignment on Rubbed Polyvinyl-Cinnamate with Overdose of UV Light

Liquid crystal (LC) alignment properties and the optical writing and erasing have been reported in the LC cell with rubbed Polyvinyl-Cinnamate (PVCi) alignment film. The azimuthal anchoring energy of the PVCi surface increased by the UV light exposure. The optical writing of twisted nematic (TN) orientation domains was demonstrated on the homogeneous orientation background in the LC cell with the UV dosage less than 2 J/cm2 from a super high pressure Hg lamp. The TN orientation changed to the homogeneous orientation again with the overdose of the UV light and the written image erased, if the LC material with the UV absorption around 313 nm of the line spectrum of the Hg lamp was used. On the other hand, when the LC without the UV light absorption was used, the LC alignment did not change and the written image was kept with the UV dosage more than 30 J/cm2.

The fate and management of high mercury-containing lamps from high technology industry

This study investigated the fate and management of high mercury-contained lamps, such as cold cathode fluorescent lamps (CCFLs), ultraviolet lamps (UV lamps), and super high pressure mercury lamps (SHPs), from high technology industries in Taiwan, using material flow analysis (MFA) method. Several organizations, such as Taiwan Environmental Protection Administration, Taiwan External Trade Development Council, the light sources manufactories, mercury-containing lamps importer, high technology industrial user, and waste mercury-containing lamps treatment facilities were interviewed in this study. According to this survey, the total mercury contained in CCFLs, UV lamps, and SHPs produced in Taiwan or imported from other countries was 886 kg in year 2004. Among the various lamps containing mercury, 57 kg mercury was exported as primary CCFLs, 7 kg mercury was wasted as defective CCFLs, and 820 kg mercury was used in the high technology industries, including 463 kg mercury contained in exported industrial products using CCFLs as components. On the contrary, only 59 kg of mercury was exported, including 57 kg in CCFLs and 2 kg in UV lamps. It reveals that 364 kg mercury was consumed in Taiwan during year 2004. In addition, 140 kg of the 364 kg mercury contained in lamps used by high technology industry was well treated through industrial waste treatment system. Among the waste mercury from high technology industry, 80 kg (57%), 53 kg (38%), and 7 kg (5%) of mercury were through domestic treatment, offshore treatment, and emission in air, respectively. Unfortunately, 224 kg waste mercury was not suitable treated, including 199 kg mercury contained in CCFL, which is a component of monitor for personal computer and liquid crystal display television, and 25 kg non-treated mercury. Thus, how to recover the mercury from the waste monitors is an important challenge of zero wastage policy in Taiwan.

Study on design of Huadian oil shale-fired circulating fluidized bed boiler

On the basis of the physical and chemical performance of Huadian oil shale and the design experience of Huadian 65 t/h oil shale-fired circulating fluidized bed (CFB) boiler operation, this paper introduces several main characteristics of oil shale, such as platy structure, high volatile and Ca/S content, and low ignition temperature, which are relevant to the design of CFB boiler, and analyses key design technologies of large-scale oil shale-fired circulating fluidized bed boiler. The design principles of large-scale oil shale-fired CFB boiler are suggested: (1) to adopt a II-shape configuration natural circulation mode with medium-temperature cyclone with downward gas exhaust, reliable antiwear technology and self-desulfurization technology; (2) to determine a circulating ratio of 6, hot state superficial air velocity of 5–6 m/s, combustion portion of about 0.5–0.6 in dense phase zone, and air velocity at the nozzle hole of air cap of 50–60 m/s; (3) to adopt an igniting system with hot gas generator below distributor plate and oil guns as auxiliary ignition device above distributor plate, and fluidized bed ash cooler retrieving the heat taken by hot slag. Lastly, the design scheme of 420 t/h superhigh pressure oil shale-fired CFB boiler is put forward and the general configuration and technical data are given at the end of this paper.

Development of a Continuous-Flow Reactor System for Conversion of Water-Soluble Organics in Supercritical Water under Superhigh Pressure

Development of a Continuous-Flow Reactor System for Conversion of Water-Soluble Organics in Supercritical Water under Superhigh Pressure

The Effect of Residual Stress on the Rupture of Sealed Parts in Super High Pressure Mercury Discharge Lamps

Super-high-pressure mercury discharge lamps have been used as UV light sources in the photolithography exposure process. It is well known that these lamps applied internal pressure is more than 1MPa and the outer bulb temperatures reach over 500°C. Thus, the safety for rupture of the lamps has been a very important issues in their design. In this study, the effects of the following two factors on the rupture characteristics of the sealed parts were investigated experimentally, (1) joule heating in the current operation, (2) heat conduction from the discharge. In addition, the finite element calculation (FEM) was carried out to investigate the stress distribution in the sealed parts. The experimental results showed that the rupture occurred in the cooling process when the maximum temperature of the sealed parts was more than 1200°C. The numerical results showed that the maximum value of the maximum principal stress σ1 occurred near the point where a rupture initiated in the experiments. In addition, the experimental results were in fairly good agreements with the FEM results. The authors proposed that the maximum temperature of the sealed parts should be less than 1000°C during operation to prevent the lamp rupture.

The study of AlN ceramics sintered at superhigh pressure with belt-type press technology

The effects of Y2O3 content, sintering time, sintering temperature, sintering pressure on thermal conductivity of AlN ceramics had been studied. X-ray diffraction (XRD), scanning electron microscope (SEM), laser conductometer and laser granularity dimension analysis measurer were respectively used to measure the phases, microstructure, thermal conductivity and particle size distribution of the samples. These studies reveal that the Y2O3 is an effective sintering addtive, and the best conditions of sintering are that the pressure is 5.15× 109 Pa, the temperature is 1700∘C and the sintering time is 115 min. Under these conditions, the sintered body has reasonable structure and its thermal conductivity is 200 w/(m⋅k).

A Study on the End Shape of the Sealed Parts of the Bulb Side in the Super High Pressure Discharge Lamps to Improve the Lamp Strength under Internal Pressure

Super high pressure mercury discharge lamps have been used as a UV and visible light sources for photolithography exposure process, such as patterning LCDs, PCBs and semiconductors. This study examines their rupture characteristics and discuss a guideline for designing a part of lamp between the end of bulb and the end of the sealed part under internal pressure. Finite-Element method (FEM) was employed to investigate the maximum principal stress σ1 distribution near the end of the sealed part. Furthermore, static water pressure tests were conducted to examine the strength characteristic of the bulbs. As the results, the rupture characteristics near the end of the sealed parts can be elucidated and the guideline for designing the end of the sealed parts were drawn up. Moreover, the relationships among the rupture pressure and the outer diameter D2 of the glass parts in the sealed parts and the length L1 near the end of the sealed parts were obtained for increasing the bulb strength. It was found that the strength near the end of the bulb was increased as the diameter D2 was decreased and the length L1 was increased. The rupture characteristics obtained by the numerical results were in fairly good agreements with those by the experiments.

Finite-Element Stress Analysis and Strength Evaluation of Super High Pressure Mercury Lamp Bulbs under Internal Pressure

Super high pressure mercury discharge lamps have been used as UV light sources for photolithography, such as patterning LCDs, PCBs and semiconductors. The bulbs of the lamps are generally made of silica glass. This study evaluates optimal shapes for various lamp bulbs under internal pressure employing the Finite Element Method (FEM). As the result, the optimal shape of the bulb was obtained and the relationship between the rupture stress and the bulb wall thickness t was clarified. The optimal shape of the bulb obtained is 0.7 ≤ D/L ≤ 0.85, where L is the total length of the bulb and D is the diameter. Static water pressure-tests were conducted in order to verify the numerical results. It was found that tendency between the numerical results and experiments were in fairly good agreement.

An Effect of Residual Stress on the Rupture Strength of Super High Pressure Mercury Discharge Lamp Bulbs

An Effect of Residual Stress on the Rupture Strength of Super High Pressure Mercury Discharge Lamp Bulbs

Bulk amorphous and nanocrystalline Fe [formula omitted]Zr [formula omitted]Nb [formula omitted]B [formula omitted] alloy by rapid consolidation at super-high pressure

Microstructure and soft magnetic properties of a bulk amorphous and nanocrystalline Fe 86 Zr 5.5 Nb 5.5 B 3 alloy prepared by rapid consolidation at a super-high pressure (at 1150 W at 5.5 GPa for 3 min) were investigated. The bulk alloy had a high relative density of 98.3% and high saturation magnetization of 120 emu/g. The size of the nanocrystalline α -Fe phase in the bulk samples was 10–16 nm. The relative density ρ r had a linear relation with the crystalline volume fraction V c in the bulk alloy: ρ r =0.6624+0.5616 V c . The preparing process used in this study makes it easy not only to generate the bulk alloy containing both amorphous and nanocrystalline phases but also to give good soft magnetic properties. And what is more important, there will be no longer restriction in the composition, size and shape of bulk alloys prepared by this process.

The characteristics of the sealed parts in super high pressure mercury discharge lamps under internal pressure

The characteristics of the sealed parts in super high pressure mercury discharge lamps under internal pressure

Influence of Plural Loads on Rupture of the Sealed Parts in Super High Pressure Mercury Discharge Lamps

Influence of Plural Loads on Rupture of the Sealed Parts in Super High Pressure Mercury Discharge Lamps