The classification, characteristics and current situation of aluminum melt hydrogen-removal methods and technologies have been summarized. The latest studies and research results of aluminum melt degassing technology ...The classification, characteristics and current situation of aluminum melt hydrogen-removal methods and technologies have been summarized. The latest studies and research results of aluminum melt degassing technology have been summed up. The tendency and prospect of aluminum degassing technology was discussed.展开更多
Examples of the mightiest energy releases by great earthquakes and volcanic eruptions and hypotheses providing explanations for them are analyzed along with the results of some recently pub- lished researches and visu...Examples of the mightiest energy releases by great earthquakes and volcanic eruptions and hypotheses providing explanations for them are analyzed along with the results of some recently pub- lished researches and visualizations. The emerging conclusions are that the mechanism of the strong earthquake is a chemical explosion; that volcanic eruption is a special type of earthquake wherein the hypocenter rises to the earth-surface; and that there is an association between the seismic-volcanic processes and mantle ＂fluids＂ and the lack of energy for mantle plumes. A conceptual system of hypoth- eses is put forward to explain the conservation of energy during Earth＇s accretion, its quasi-stable release by primordial H- and He-degassing and of the crucial role of the energy of degassing-eomprising- reactions in endogenic processes. Specific mechanisms and chemical processes are proposed for the gas-liquid mantle plumes melting through the solid mantle using heat-energy released in reactions of their metamorphic and chemical transformation under gradual decrease of pressure and temperature; volcanic gases are put forward as energy carriers. 3He performance as a unique measuring transformer correlative to the internal heat flow was used for calculation of energy release by degassing; it equals to 5.12 × 1020 J/yr, an amount of energy five-fold greater than the entire energy loss involved in earthquake and volcanic activity. The hypotheses proposed are objectively testable.展开更多
The effect of ultrasonic power and treatment time on degassing of Mg-6Zn-1Ca alloy was studied in this paper. The degassing effect was characterized by measuring densities of ingots. The results show that proper ultra...The effect of ultrasonic power and treatment time on degassing of Mg-6Zn-1Ca alloy was studied in this paper. The degassing effect was characterized by measuring densities of ingots. The results show that proper ultrasonic treatment can remove hydrogen from the melt of the Mg-6Zn-1Ca alloy. The ultrasonic degassing effect is closely related to the ultrasonic power density and treatment time. The degassing efficiency increases with an increase in ultrasonic power density when the melt is treated at 690 °C for 120 s, reaching its highest value at 1.2 W·cm-3. When the power density is 1.2 W·cm-3, with an increase in ultrasonic treatment time, the degassing efficiency increases at first, reaches its peak value at 120 s, then decreases as the ultrasonic treatment is further prolonged. In this experiment, the optimum degassing effect with an efficiency of 67.5 % is obtained by ultrasonic treatment with the power density of 1.2 W·cm-3 for 120 s. The maximum density of ingot can be increased from 1.8069 g·cm-3 to 1.8146 g·cm-3(increased by 0.43%).展开更多
In the process of semi-solid slurry preparation with direct ultrasonic vibration (UV) by dipping the horn into the melt, one of the questions is whether the gas content in the melt would be increased or not by the cav...In the process of semi-solid slurry preparation with direct ultrasonic vibration (UV) by dipping the horn into the melt, one of the questions is whether the gas content in the melt would be increased or not by the cavitation effect of ultrasonic vibration. By application of quantitative gas content measurement technique, this paper investigated the effect of the ultrasonic vibration on the gas content of both the melt and the semi-solid slurry of Al-Si alloys, and the variations of the gas contents in two kinds of aluminum alloys, i.e., A356 alloy and Al-20Si-2Cu-1Ni-0.6RE alloy (Al-20Si for short). The results show that ultrasonic vibration has an obvious degassing effect on the molten melt, especially on the semi-solid slurry of Al-Si alloy which is below the liquidus temperature by less than 20 ℃. The ultrasonic degassing efficiency of the A356 alloy decreases with the reduction of the initial gas content in the melt, and it is nearly unchanged for the Al-20Si alloy. The gas content of both alloys decreases when the ultrasonic vibration time is increased. The best vibration time for Al-20Si alloy at the liquid temperature of 710 ℃ and semi-solid temperature of 680 ℃ is 60 s and 90 s, respectively; and the degassing efficiency is 48% and 35%, respectively. The mechanism of ultrasonic degassing effect is discussed.展开更多
The effect of high intensity ultrasound based on the novel multi-frequency multimode modulated technology on the final density, porosity, mechanical and fatigue properties of an AlSi<sub>9</sub>Cu<sub&g...The effect of high intensity ultrasound based on the novel multi-frequency multimode modulated technology on the final density, porosity, mechanical and fatigue properties of an AlSi<sub>9</sub>Cu<sub>3</sub>(Fe) alloy after different processing time was studied. Reduced pressure test was used to evaluate the density of alloys. The tensile and fatigue tests were used to evaluate the static and dynamic properties for the different time of ultrasonic degassing, respectively. It is found that ultrasonic degassing is effective in reduction porosity as well as to improve the final density of castings. Furthermore, the experimental results suggest that the porosity level does not have a substantial influence on the static properties contrary to what is observed on fatigue properties.展开更多
The 2024 aluminum alloy was prepared with different ultrasonic processes.Effects of ultrasonic treatment parameters including ultrasonic power,treatment time,treatment temperature,and frequency resonance,as well as C_...The 2024 aluminum alloy was prepared with different ultrasonic processes.Effects of ultrasonic treatment parameters including ultrasonic power,treatment time,treatment temperature,and frequency resonance,as well as C_(2)Cl_(6) degasser on degassing of the 2024 aluminum alloy were investigated.Results indicate that increasing ultrasonic power at the same ultrasonic treatment time can improve the degassing effect.The optimum degassing efficiency can be obtained under the resonant ultrasound condition.With the combination of 1%C_(2)Cl_(6) addition and 150 W ultrasonic treatment for 40 s,the hydrogen content of the alloy is decreased by 52.9%.At the same time,the tensile strength and elongation are increased by 28.3%and 92.3%,respectively,and the yield strength is slightly increased by 6.7%.The degassing mechanism is also discussed.展开更多
In the degassing process of transformer oil with ultrasonic waves, decomposition of the oil was observed. Light hydrocarbons, including methane, ethane, ethylene, acetylene, propane etc, were found to be released con...In the degassing process of transformer oil with ultrasonic waves, decomposition of the oil was observed. Light hydrocarbons, including methane, ethane, ethylene, acetylene, propane etc, were found to be released continuously from the oil into headspace within a closed vial placed in an ultrasonic field. The gases came from decomposition of hydrocarbon molecules under cavitation effect.展开更多
In order to improve the plasticity of 4004 AI alloy and subsequently the productivity of 4004 AI foil, the research studied in detail the influence of the rotary impeller degassing process on the refining effect of 40...In order to improve the plasticity of 4004 AI alloy and subsequently the productivity of 4004 AI foil, the research studied in detail the influence of the rotary impeller degassing process on the refining effect of 4004 AI alloy, in which the impacts of four major parameters： gas flow, rotational speed, refining time, and stewing time, on degassing rate of 4004 AI alloy was systematically studied by using an orthogonal experiment methodology. Results show that the rotational speed has the greatest impact on the degassing of 4004 AI alloy, followed by gas flow and refining time; stewing time has the least impact. The optimum purification parameters obtained by current orthogonal analysis were： rotor speed of 500 r.min1, inert gas flow of 0.4 mL.h-1, refining time of 15 min, and stewing time of 6 min. Degassing rate using the optimum parameters reaches 68%. In addition~ the comparison experiments among C2CI6 refining, rotary impeller degassing, and combined treatment of C2CI6 refining and rotary impeller degassing for 4004 AI alloy were performed. The experimental data indicated that the combined treatment of C2CI6 refining and rotary impeller degassing has the best degassing effect. Degassing rate of C2CI6 refining, rotary impeller degassing and combined refining treatment is 39%, 69.1% and 76.9%, respectively. The mechanical properties of the specimen refined by rotary impeller degassing were higher than those by C2CI6 refining, but lower than those by combined refining treatment.展开更多
To lower the CO 2 risk for hydrocarbon exploration in the west continental shelf of Yinggehai basin, South China Sea, we do attempt not only to know the CO 2 origins, but also to make an understanding of the degassi...To lower the CO 2 risk for hydrocarbon exploration in the west continental shelf of Yinggehai basin, South China Sea, we do attempt not only to know the CO 2 origins, but also to make an understanding of the degassing processes from the mantle and crust. Based on the stable carbon isotope ratios of CO 2 alone, the organic and inorganic CO 2 can be successively distinguished, but the formation conditions and mixing processes for inorganic CO 2 are still not clear. The relationships between lg[R(= 3He/ 4He)/R a(=1.386×10 -6)] and CO 2 content (%), CO 2/ 3He and δ 13C CO 2 have been employed, respectively, to obtain that the CO 2 gases in the reservoirs can be classified into three categories: (1) organic CO 2 with very low contents but contaminated by mantle-derived helium; (2) inorganic CO 2 gases with lower to higher contents being mixtures of crustal CO 2 with mantle-derived CO 2, the mantle- contributed percentage being in the range of 0 %-27 %, and (3) mainly crust-derived inorganic CO 2 gases being characterized by high contents (more than 50 %) and indicating the crustal addition by metamorphism of rich-in carbon rocks in basement. Nevertheless, some CO 2/ 3He ratios of organic CO 2 fall into the range 10 8-10 10, which made us inquire whether the CO 2/ 3He=(1-10)×10 9 can be the unique signature of magmatic CO 2 or not. All the observation of plutonic activities, fluid inclusion measurements in gas reservoirs, pre-stack depth/time seismic sections and the satellite infrared remote photography taken from Yinggehai basin, South China Sea, during Chichi earthquake in Taiwan on September 21, 1999, supports that the degassing processes are in a discontinuous mode, which may be triggered by igneous intrusion or extrusion, or earthquakes. In the central diapir zone of the basin, at least 3 to 4 orders of discharge of across-formational thermal fluid flows through fractures can be determined in different scales. The mantle degassing process may have a strong effect on overpressured system forming and outgassing in crust. However, it is very difficult to estimate the transferring rates for a special fractured zone at a specific time interval.展开更多
The currently accepted theory of self-exciting dynamo generating magnetic field of the Earth and its shortage of energy is critically reviewed. Based on thermodynamic approach, a new hypothesis of the Earth’s magneti...The currently accepted theory of self-exciting dynamo generating magnetic field of the Earth and its shortage of energy is critically reviewed. Based on thermodynamic approach, a new hypothesis of the Earth’s magnetic field, created by thermo-electrochemical processes of the Earth’s degassing, gravitational differentiation and their energy, is proposed. The ion-exchange, extraction and solidification are sources of the ionic currents on solid core and lower mantle boundaries. These currents are carried by thermo-chemical flows, which create the primary exciting magnetic field. This field is amplified mostly by thermoelectricity generated by heat flow thus improving the heat and matter transport from the Earth’s core and lower mantle to surface. Migration of the solidification zones and inner core precession are the main causes of changes of the main magnetic field intensity and reversals of its polarity.展开更多
This article presents the evidence in support of the direct magma degassing as the principal mechanism of volatiles releasing into the hydrothermal fluids in the Okinawa Trough, as contrasted to the argument for the h...This article presents the evidence in support of the direct magma degassing as the principal mechanism of volatiles releasing into the hydrothermal fluids in the Okinawa Trough, as contrasted to the argument for the hydrothermal stripping of volatiles from the volcanic rocks.\ Laser Raman microprobe and stepped-heating techniques are employed to determine the compositions and contents of the volatiles in pumices in the middle Okinawa Trough. The results show that the volatiles are similar to the gases in the hydrothermal fluids and hydrothermal minerals in composition, the mean percent content of each component and variation trend. This indicates the direct influence of magma degassing on the hydrothermal fluids. In addition, the contents of volatiles in pumices are rather low and do not support the hydrothermal stripping as the main mechanism to enrich the fluids with gases. The results are consistent with the idea that the direct magma degassing is more important than hydrothermal stripping in supplying gases to the hydrothermal fluids in the Okinawa Trough.展开更多
:Reactivation of metasomatized mantle lithosphere may occur during continental extension,which is an important component of plate tectonics.The lower most part of the metasomatized domains in the subcontinental mantle...:Reactivation of metasomatized mantle lithosphere may occur during continental extension,which is an important component of plate tectonics.The lower most part of the metasomatized domains in the subcontinental mantle lithosphere can be locally enriched in CO2.Therefore,partial melting of these metasomatized domains may play a crucial role in the global carbon cycle.However,little is known about this process and up until now few numerical constraints are available.Here we address this knowledge gap and use a 2-D high resolution petrological-thermomechanical model to assess lithospheric rifting.CO2 degassing and melting.We test 4 lithospheric thicknesses:90,110,130 and 200 km with a 10 km thick metasomatized layer at the base using CO2 of 2 wt.%in the bulk composition.The carbonate enriched layer is stable below^3 GPa(>110 km)for a temperature of 1300℃;therefore,we only observe degassing patterns for lithospheric models that are 130 km and 200 km thick.The metasomatized layer for the 130 km thick lithosphere mostly comprises carbonatite melting,whereas in the 200 km thick scenario propagation of melt development from kimberlites to carbonatites occurs as the metasomatic mantle is exhumed during extension.The numerical models fit well into natural rifting zones of the European Cenozoic Rift System for young(shallow)and of the North Atlantic Rift for old(thick)lithosphere.展开更多
Degassing is very important for aluminum alloys especially for 7xxx series alloys. In the present study, a high shear technology was used to degas 7032 aluminum alloy in order to study its degassing efficiency. The ex...Degassing is very important for aluminum alloys especially for 7xxx series alloys. In the present study, a high shear technology was used to degas 7032 aluminum alloy in order to study its degassing efficiency. The experimental results showed that the high shear technology can significantly degas 7032 aluminum alloy. By applying intensive melt shearing and an Ar injection of 60 seconds, the density index, D,, was reduced from 13.25% to 0.28% and the hydrogen concentration was significantly i＇educed from 0.31 to 0.10 mL/100g AI. Compared with the conventional rotary degassing, high shear technology showed a much higher degassing efficiency, achieving a lower concentration of hydrogen in a shorter time. The water simulation experiment was used to study the mechanism of the high degassing efficiency. The small bubble size and the uniform distribution of Ar bubbles with the application of high shear technology are believed to be the main cause for the high degassing efficiency.展开更多
This paper conducts a comparative analysis of the anti-wetting properties and degassing performance of both homemade and commercial membranes.Additionally,it introduces a unique approach to hydrophobic modification of...This paper conducts a comparative analysis of the anti-wetting properties and degassing performance of both homemade and commercial membranes.Additionally,it introduces a unique approach to hydrophobic modification of high-flux membranes.The study involved the utilization of Hyflon AD40L for multiple coatings on the surface of polypropylene(PP)hollow fiber membranes.Several variables,including modification solution concentration,temperature,coating duration,number of coating cycles,polymer type,and the choice and concentration of the pore-blocking agent,were systematically investigated to establish the optimal modification process.Characterization of the modified membrane and degassing experiments revealed significant improvements.Specifically,the contact angle increased from 95.5°to 113.1°,while the trans-membrane differential pressure surged from 10.7 kPa to 154.6 kPa,marking a remarkable 14.4-fold enhancement.This enhancement is attributed to the improved antiwetting capabilities of the modified membrane.In the degassing experiments,the modified membrane-based module demonstrated an impressive 95.0%dissolved oxygen removal rate,with a corresponding mass transfer coefficient reaching 18.01×10^(-3)m·h^(-1).These results underscore the substantial potential of the Hyflon AD40 L/PP membrane for applications in membrane degassing.展开更多
The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process couM be determined by the results of theoretical calculation of motion of ...The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process couM be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets wouM solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results,展开更多
The paper studies CO2 degassing and controlling factors under the condition of contact metamorphism in the Shuangshan area, southern Tan-Lu fault belt and the method of calculating the amount of CO2 degassing. The res...The paper studies CO2 degassing and controlling factors under the condition of contact metamorphism in the Shuangshan area, southern Tan-Lu fault belt and the method of calculating the amount of CO2 degassing. The results show that the amount of CO2 degassing is controlled by the characteristics of the country rocks, including the thermal conductivity, penetrability, porosity and connectivity. Compositions, size and depth of intrusive rock also have an important influence on CO2 degassing, i.e., they generated numerous cracks in the country rocks, and thus allowed the easy flow and accumulation of fluids. The amount of CO2 flux in contact metamorphism is calculated quantitatively based on the metamorphic reaction and time-integrated fluid flux. The value （0.729- 2.446×10^4 mol/cm^2） of CO2 flux suggests that CO2 was provided mainly by the contact metamorphic reaction. The generation and releasing of CO2 are positively correlated with the degree of metamorphism, and XCO2 in fluids gradually increases from dolomite zone to calcite zone, but in the zone of grossular, fluid flux is the largest and XCO2 sharply decreases due to involvement of magmatic water. This study presents evidence that a large amount of industrial-scale CO2 can be produced during contact metamorphism. On the basis of theoretical and practical studies, a cone model has been proposed to response CO2 degassing for the contact metamorphism, and it can be used to explore CO2 accumulations beyond the oil-gas basins. This model can also be applied to the study of inorganic genesis of CO2 accumulations.展开更多
An effective vacuum melting technique based on the improved vacuum degassing technique was used to produce thick-walled seamless pipes of 9Cr-1Mo-V-Nb-N martensitic heat resistant steels in order to reduce the content...An effective vacuum melting technique based on the improved vacuum degassing technique was used to produce thick-walled seamless pipes of 9Cr-1Mo-V-Nb-N martensitic heat resistant steels in order to reduce the contents of harmful impurity such as oxygen, phosphorus. Then the pipe was heat treated by using optimized process technique. Both static and dynamic mechanical properties at room temperature and 566℃ were measured respectively and evaluated by means of comprehensive analysis of standard deviation and statistic test. The results show that the comprehensive mechanical properties of this pipe are much better than those of pipes untreated with the improved vacuum degassing technique and heat-treated by using original heat-treatment process and almost the same as those of imported P91 thick-walled seamless steel pipe.展开更多
Over the past decades,membrane-based separation processes have found numerous applications in various industries.Membrane contactor is an important part of the separation of dissolved gas in the early stage of gas det...Over the past decades,membrane-based separation processes have found numerous applications in various industries.Membrane contactor is an important part of the separation of dissolved gas in the early stage of gas detection.In this paper,to improve efficiency in the detection of the dissolved gas phase in seawater,a better flat membrane contactor is proposed to achieve efficient degassing,inspired by the way fish breathe underwater and the special structure of fish gills.The bioinspired flow channel structures in the flat membrane contactor are suggested along with the distribution of internal blood vessels in the gill platelet and the feature of the gill platelet surface.Using 3D printing,the special degassing devices are manufactured,and comparative analysis of relevant flow parameters is made using different flow channels,combined with the CFD simulation.The final result showed that the proposed flow channel in the degasser achieves a better degassing effect compared with conventional flow channel when the membrane contact area is limited,which can provide good conditions for subsequent gas detection.展开更多
This work was aimed to investigate the effect of helium degassing of cattle-manure-compost (CMC) based activated carbons on the adsorptive removal of copper ions from aqueous solution. Degassing temperatures were 500...This work was aimed to investigate the effect of helium degassing of cattle-manure-compost (CMC) based activated carbons on the adsorptive removal of copper ions from aqueous solution. Degassing temperatures were 500℃, 800℃ and 1000℃. Activated carbons were characterized according to surface chemistry and pore structures. Adsorption of copper ions was carried out using the conventional bottle-point technique to which the equilibrium data were correlated to Langmuir and Freundlich models. Results indicated that the uptake of copper ions could be well characterized by Langmuir model. It was found that the adsorption of copper ions decreased with significant decrease in surface area as a result of helium degassing at higher temperature. The increase of electron density on graphene layers offered higher affinity towards copper ions at lower equilibrium concentration. It was inferred that copper ions favorably adsorbed on mesopores at lower equilibrium concentration and switched to micropores at higher equilibrium concentration.展开更多
The warming of Antarctica observed in recent years is one of the consequences of deep degassing associated with the northward drift of the Earth’s core. Ascending streams of hydrogen and other gases move along the te...The warming of Antarctica observed in recent years is one of the consequences of deep degassing associated with the northward drift of the Earth’s core. Ascending streams of hydrogen and other gases move along the tectonic faults of the lithosphere. When they get into an oxidizing environment, there is an increase in the amount of water in the ocean and air, which is accompanied by a decrease in oxygen concentrations and the release of huge amounts of energy. The provisions of the proposed theory were tested using the method of mental critical experiment. The reality of atmospheric effects of subsurface degassing is confirmed by the facts of synchronous destruction of ozone in the stratosphere and an increase in the temperature of the surface air layer. These events usually coincide with releases of ozone-depleting and heat-generating hydrogen from the subsurface.展开更多
文摘The classification, characteristics and current situation of aluminum melt hydrogen-removal methods and technologies have been summarized. The latest studies and research results of aluminum melt degassing technology have been summed up. The tendency and prospect of aluminum degassing technology was discussed.
文摘Examples of the mightiest energy releases by great earthquakes and volcanic eruptions and hypotheses providing explanations for them are analyzed along with the results of some recently pub- lished researches and visualizations. The emerging conclusions are that the mechanism of the strong earthquake is a chemical explosion; that volcanic eruption is a special type of earthquake wherein the hypocenter rises to the earth-surface; and that there is an association between the seismic-volcanic processes and mantle ＂fluids＂ and the lack of energy for mantle plumes. A conceptual system of hypoth- eses is put forward to explain the conservation of energy during Earth＇s accretion, its quasi-stable release by primordial H- and He-degassing and of the crucial role of the energy of degassing-eomprising- reactions in endogenic processes. Specific mechanisms and chemical processes are proposed for the gas-liquid mantle plumes melting through the solid mantle using heat-energy released in reactions of their metamorphic and chemical transformation under gradual decrease of pressure and temperature; volcanic gases are put forward as energy carriers. 3He performance as a unique measuring transformer correlative to the internal heat flow was used for calculation of energy release by degassing; it equals to 5.12 × 1020 J/yr, an amount of energy five-fold greater than the entire energy loss involved in earthquake and volcanic activity. The hypotheses proposed are objectively testable.
基金supported by the Major State Basic Research Development Program of China(2013CB632203)the National Key Technology R&D Program of China(2012BAF09B01)+2 种基金the Liaoning Provincial Natural Science Foundation(Grant No.201202072)the Program for Liaoning Excellent Talents in University(Grant No.LJQ2012023)the Fundamental Research Foundation of Central Universities(N120509002 and N120309003)
文摘The effect of ultrasonic power and treatment time on degassing of Mg-6Zn-1Ca alloy was studied in this paper. The degassing effect was characterized by measuring densities of ingots. The results show that proper ultrasonic treatment can remove hydrogen from the melt of the Mg-6Zn-1Ca alloy. The ultrasonic degassing effect is closely related to the ultrasonic power density and treatment time. The degassing efficiency increases with an increase in ultrasonic power density when the melt is treated at 690 °C for 120 s, reaching its highest value at 1.2 W·cm-3. When the power density is 1.2 W·cm-3, with an increase in ultrasonic treatment time, the degassing efficiency increases at first, reaches its peak value at 120 s, then decreases as the ultrasonic treatment is further prolonged. In this experiment, the optimum degassing effect with an efficiency of 67.5 % is obtained by ultrasonic treatment with the power density of 1.2 W·cm-3 for 120 s. The maximum density of ingot can be increased from 1.8069 g·cm-3 to 1.8146 g·cm-3(increased by 0.43%).
基金supported by the National Natural Science Foundation of China (No. 50775086)the National Basic Research Program of China (973 Program, No. 2012CB619600)
文摘In the process of semi-solid slurry preparation with direct ultrasonic vibration (UV) by dipping the horn into the melt, one of the questions is whether the gas content in the melt would be increased or not by the cavitation effect of ultrasonic vibration. By application of quantitative gas content measurement technique, this paper investigated the effect of the ultrasonic vibration on the gas content of both the melt and the semi-solid slurry of Al-Si alloys, and the variations of the gas contents in two kinds of aluminum alloys, i.e., A356 alloy and Al-20Si-2Cu-1Ni-0.6RE alloy (Al-20Si for short). The results show that ultrasonic vibration has an obvious degassing effect on the molten melt, especially on the semi-solid slurry of Al-Si alloy which is below the liquidus temperature by less than 20 ℃. The ultrasonic degassing efficiency of the A356 alloy decreases with the reduction of the initial gas content in the melt, and it is nearly unchanged for the Al-20Si alloy. The gas content of both alloys decreases when the ultrasonic vibration time is increased. The best vibration time for Al-20Si alloy at the liquid temperature of 710 ℃ and semi-solid temperature of 680 ℃ is 60 s and 90 s, respectively; and the degassing efficiency is 48% and 35%, respectively. The mechanism of ultrasonic degassing effect is discussed.
基金supported by FEDER/COMPETE fundsnational funds through FCT-Portuguese Foundation for Science and Technology and was developed on the aim of the research project PTDC/EME-TME/119658/2010 and the Post-Doctoral grant SFRH/BPD/76680/2011
文摘The effect of high intensity ultrasound based on the novel multi-frequency multimode modulated technology on the final density, porosity, mechanical and fatigue properties of an AlSi<sub>9</sub>Cu<sub>3</sub>(Fe) alloy after different processing time was studied. Reduced pressure test was used to evaluate the density of alloys. The tensile and fatigue tests were used to evaluate the static and dynamic properties for the different time of ultrasonic degassing, respectively. It is found that ultrasonic degassing is effective in reduction porosity as well as to improve the final density of castings. Furthermore, the experimental results suggest that the porosity level does not have a substantial influence on the static properties contrary to what is observed on fatigue properties.
基金financially supported by the National Natural Science Foundation of China(Grant No.51901037)the China Post-doctoral Science Foundation(Grant No.2019M661122)+1 种基金the Liaoning Province Doctoral Research Startup Fund Project(Grant Nos.2019-BS-083,2019-BS-168)the Natural Science Foundation of Liaoning Province,China(Grant Nos.2019-ZD-0561,2019-ZD-0544)。
文摘The 2024 aluminum alloy was prepared with different ultrasonic processes.Effects of ultrasonic treatment parameters including ultrasonic power,treatment time,treatment temperature,and frequency resonance,as well as C_(2)Cl_(6) degasser on degassing of the 2024 aluminum alloy were investigated.Results indicate that increasing ultrasonic power at the same ultrasonic treatment time can improve the degassing effect.The optimum degassing efficiency can be obtained under the resonant ultrasound condition.With the combination of 1%C_(2)Cl_(6) addition and 150 W ultrasonic treatment for 40 s,the hydrogen content of the alloy is decreased by 52.9%.At the same time,the tensile strength and elongation are increased by 28.3%and 92.3%,respectively,and the yield strength is slightly increased by 6.7%.The degassing mechanism is also discussed.
文摘In the degassing process of transformer oil with ultrasonic waves, decomposition of the oil was observed. Light hydrocarbons, including methane, ethane, ethylene, acetylene, propane etc, were found to be released continuously from the oil into headspace within a closed vial placed in an ultrasonic field. The gases came from decomposition of hydrocarbon molecules under cavitation effect.
基金supported by the Heilongjiang Province Natural Science Foundation(ZD20081901)the Foundation of Heilongjiang Educational Committee(11541051)
文摘In order to improve the plasticity of 4004 AI alloy and subsequently the productivity of 4004 AI foil, the research studied in detail the influence of the rotary impeller degassing process on the refining effect of 4004 AI alloy, in which the impacts of four major parameters： gas flow, rotational speed, refining time, and stewing time, on degassing rate of 4004 AI alloy was systematically studied by using an orthogonal experiment methodology. Results show that the rotational speed has the greatest impact on the degassing of 4004 AI alloy, followed by gas flow and refining time; stewing time has the least impact. The optimum purification parameters obtained by current orthogonal analysis were： rotor speed of 500 r.min1, inert gas flow of 0.4 mL.h-1, refining time of 15 min, and stewing time of 6 min. Degassing rate using the optimum parameters reaches 68%. In addition~ the comparison experiments among C2CI6 refining, rotary impeller degassing, and combined treatment of C2CI6 refining and rotary impeller degassing for 4004 AI alloy were performed. The experimental data indicated that the combined treatment of C2CI6 refining and rotary impeller degassing has the best degassing effect. Degassing rate of C2CI6 refining, rotary impeller degassing and combined refining treatment is 39%, 69.1% and 76.9%, respectively. The mechanical properties of the specimen refined by rotary impeller degassing were higher than those by C2CI6 refining, but lower than those by combined refining treatment.
文摘To lower the CO 2 risk for hydrocarbon exploration in the west continental shelf of Yinggehai basin, South China Sea, we do attempt not only to know the CO 2 origins, but also to make an understanding of the degassing processes from the mantle and crust. Based on the stable carbon isotope ratios of CO 2 alone, the organic and inorganic CO 2 can be successively distinguished, but the formation conditions and mixing processes for inorganic CO 2 are still not clear. The relationships between lg[R(= 3He/ 4He)/R a(=1.386×10 -6)] and CO 2 content (%), CO 2/ 3He and δ 13C CO 2 have been employed, respectively, to obtain that the CO 2 gases in the reservoirs can be classified into three categories: (1) organic CO 2 with very low contents but contaminated by mantle-derived helium; (2) inorganic CO 2 gases with lower to higher contents being mixtures of crustal CO 2 with mantle-derived CO 2, the mantle- contributed percentage being in the range of 0 %-27 %, and (3) mainly crust-derived inorganic CO 2 gases being characterized by high contents (more than 50 %) and indicating the crustal addition by metamorphism of rich-in carbon rocks in basement. Nevertheless, some CO 2/ 3He ratios of organic CO 2 fall into the range 10 8-10 10, which made us inquire whether the CO 2/ 3He=(1-10)×10 9 can be the unique signature of magmatic CO 2 or not. All the observation of plutonic activities, fluid inclusion measurements in gas reservoirs, pre-stack depth/time seismic sections and the satellite infrared remote photography taken from Yinggehai basin, South China Sea, during Chichi earthquake in Taiwan on September 21, 1999, supports that the degassing processes are in a discontinuous mode, which may be triggered by igneous intrusion or extrusion, or earthquakes. In the central diapir zone of the basin, at least 3 to 4 orders of discharge of across-formational thermal fluid flows through fractures can be determined in different scales. The mantle degassing process may have a strong effect on overpressured system forming and outgassing in crust. However, it is very difficult to estimate the transferring rates for a special fractured zone at a specific time interval.
文摘The currently accepted theory of self-exciting dynamo generating magnetic field of the Earth and its shortage of energy is critically reviewed. Based on thermodynamic approach, a new hypothesis of the Earth’s magnetic field, created by thermo-electrochemical processes of the Earth’s degassing, gravitational differentiation and their energy, is proposed. The ion-exchange, extraction and solidification are sources of the ionic currents on solid core and lower mantle boundaries. These currents are carried by thermo-chemical flows, which create the primary exciting magnetic field. This field is amplified mostly by thermoelectricity generated by heat flow thus improving the heat and matter transport from the Earth’s core and lower mantle to surface. Migration of the solidification zones and inner core precession are the main causes of changes of the main magnetic field intensity and reversals of its polarity.
基金This work was supported by the Major State Basic Research Program(No.G2000078503)Shandong Natural Science Foundation(No.Y2000E06).
文摘This article presents the evidence in support of the direct magma degassing as the principal mechanism of volatiles releasing into the hydrothermal fluids in the Okinawa Trough, as contrasted to the argument for the hydrothermal stripping of volatiles from the volcanic rocks.\ Laser Raman microprobe and stepped-heating techniques are employed to determine the compositions and contents of the volatiles in pumices in the middle Okinawa Trough. The results show that the volatiles are similar to the gases in the hydrothermal fluids and hydrothermal minerals in composition, the mean percent content of each component and variation trend. This indicates the direct influence of magma degassing on the hydrothermal fluids. In addition, the contents of volatiles in pumices are rather low and do not support the hydrothermal stripping as the main mechanism to enrich the fluids with gases. The results are consistent with the idea that the direct magma degassing is more important than hydrothermal stripping in supplying gases to the hydrothermal fluids in the Okinawa Trough.
基金sponsored by ARC Centre of Excellence for Core toCrust Fluid Systemsprovided by the Pawsey Supercomputing Centre with funding from the Australian Government and the Government of Western Australia
文摘:Reactivation of metasomatized mantle lithosphere may occur during continental extension,which is an important component of plate tectonics.The lower most part of the metasomatized domains in the subcontinental mantle lithosphere can be locally enriched in CO2.Therefore,partial melting of these metasomatized domains may play a crucial role in the global carbon cycle.However,little is known about this process and up until now few numerical constraints are available.Here we address this knowledge gap and use a 2-D high resolution petrological-thermomechanical model to assess lithospheric rifting.CO2 degassing and melting.We test 4 lithospheric thicknesses:90,110,130 and 200 km with a 10 km thick metasomatized layer at the base using CO2 of 2 wt.%in the bulk composition.The carbonate enriched layer is stable below^3 GPa(>110 km)for a temperature of 1300℃;therefore,we only observe degassing patterns for lithospheric models that are 130 km and 200 km thick.The metasomatized layer for the 130 km thick lithosphere mostly comprises carbonatite melting,whereas in the 200 km thick scenario propagation of melt development from kimberlites to carbonatites occurs as the metasomatic mantle is exhumed during extension.The numerical models fit well into natural rifting zones of the European Cenozoic Rift System for young(shallow)and of the North Atlantic Rift for old(thick)lithosphere.
基金financially supported by the National Natural Science Foundation of China(51104043 and 51374067)the Outstanding Young Scholars Growth Plan in the Colleges and Universities of Liaoning Province(LJQ2014032)the National Basic Research Program of China(2012CB619506)
文摘Degassing is very important for aluminum alloys especially for 7xxx series alloys. In the present study, a high shear technology was used to degas 7032 aluminum alloy in order to study its degassing efficiency. The experimental results showed that the high shear technology can significantly degas 7032 aluminum alloy. By applying intensive melt shearing and an Ar injection of 60 seconds, the density index, D,, was reduced from 13.25% to 0.28% and the hydrogen concentration was significantly i＇educed from 0.31 to 0.10 mL/100g AI. Compared with the conventional rotary degassing, high shear technology showed a much higher degassing efficiency, achieving a lower concentration of hydrogen in a shorter time. The water simulation experiment was used to study the mechanism of the high degassing efficiency. The small bubble size and the uniform distribution of Ar bubbles with the application of high shear technology are believed to be the main cause for the high degassing efficiency.
基金financial support of the National Key Research and Development Program of China(2020YFC0862903)the National Natural Science Foundation of China(22078146)+2 种基金the Key Research and Development program of Jiangsu Province(BE2021022)the Materials-Oriented Chemical Engineering State Key Laboratory Program(KL19-04)the Natural Science Foundation of Jiangsu Province(BK20200091).
文摘This paper conducts a comparative analysis of the anti-wetting properties and degassing performance of both homemade and commercial membranes.Additionally,it introduces a unique approach to hydrophobic modification of high-flux membranes.The study involved the utilization of Hyflon AD40L for multiple coatings on the surface of polypropylene(PP)hollow fiber membranes.Several variables,including modification solution concentration,temperature,coating duration,number of coating cycles,polymer type,and the choice and concentration of the pore-blocking agent,were systematically investigated to establish the optimal modification process.Characterization of the modified membrane and degassing experiments revealed significant improvements.Specifically,the contact angle increased from 95.5°to 113.1°,while the trans-membrane differential pressure surged from 10.7 kPa to 154.6 kPa,marking a remarkable 14.4-fold enhancement.This enhancement is attributed to the improved antiwetting capabilities of the modified membrane.In the degassing experiments,the modified membrane-based module demonstrated an impressive 95.0%dissolved oxygen removal rate,with a corresponding mass transfer coefficient reaching 18.01×10^(-3)m·h^(-1).These results underscore the substantial potential of the Hyflon AD40 L/PP membrane for applications in membrane degassing.
文摘The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process couM be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets wouM solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results,
基金supported by grants from the Natural Science Foundation of China(grant Nos:40473021 and 40472074)the National Basic Research Program of China(grant No:2003CB214600).
文摘The paper studies CO2 degassing and controlling factors under the condition of contact metamorphism in the Shuangshan area, southern Tan-Lu fault belt and the method of calculating the amount of CO2 degassing. The results show that the amount of CO2 degassing is controlled by the characteristics of the country rocks, including the thermal conductivity, penetrability, porosity and connectivity. Compositions, size and depth of intrusive rock also have an important influence on CO2 degassing, i.e., they generated numerous cracks in the country rocks, and thus allowed the easy flow and accumulation of fluids. The amount of CO2 flux in contact metamorphism is calculated quantitatively based on the metamorphic reaction and time-integrated fluid flux. The value （0.729- 2.446×10^4 mol/cm^2） of CO2 flux suggests that CO2 was provided mainly by the contact metamorphic reaction. The generation and releasing of CO2 are positively correlated with the degree of metamorphism, and XCO2 in fluids gradually increases from dolomite zone to calcite zone, but in the zone of grossular, fluid flux is the largest and XCO2 sharply decreases due to involvement of magmatic water. This study presents evidence that a large amount of industrial-scale CO2 can be produced during contact metamorphism. On the basis of theoretical and practical studies, a cone model has been proposed to response CO2 degassing for the contact metamorphism, and it can be used to explore CO2 accumulations beyond the oil-gas basins. This model can also be applied to the study of inorganic genesis of CO2 accumulations.
文摘An effective vacuum melting technique based on the improved vacuum degassing technique was used to produce thick-walled seamless pipes of 9Cr-1Mo-V-Nb-N martensitic heat resistant steels in order to reduce the contents of harmful impurity such as oxygen, phosphorus. Then the pipe was heat treated by using optimized process technique. Both static and dynamic mechanical properties at room temperature and 566℃ were measured respectively and evaluated by means of comprehensive analysis of standard deviation and statistic test. The results show that the comprehensive mechanical properties of this pipe are much better than those of pipes untreated with the improved vacuum degassing technique and heat-treated by using original heat-treatment process and almost the same as those of imported P91 thick-walled seamless steel pipe.
基金funded by Science-Technology Development Plan Project of Jilin Province,20210203099SF,Zhiyong ChangScience and Technology Development Project of Jilin Province,20190303061SF,Yongming Yao13th Five-Year Plan Scientific Research Foundation of the Education Department of Jilin Province,JJKH20190190KJ,Zhiyong Chang.
文摘Over the past decades,membrane-based separation processes have found numerous applications in various industries.Membrane contactor is an important part of the separation of dissolved gas in the early stage of gas detection.In this paper,to improve efficiency in the detection of the dissolved gas phase in seawater,a better flat membrane contactor is proposed to achieve efficient degassing,inspired by the way fish breathe underwater and the special structure of fish gills.The bioinspired flow channel structures in the flat membrane contactor are suggested along with the distribution of internal blood vessels in the gill platelet and the feature of the gill platelet surface.Using 3D printing,the special degassing devices are manufactured,and comparative analysis of relevant flow parameters is made using different flow channels,combined with the CFD simulation.The final result showed that the proposed flow channel in the degasser achieves a better degassing effect compared with conventional flow channel when the membrane contact area is limited,which can provide good conditions for subsequent gas detection.
文摘This work was aimed to investigate the effect of helium degassing of cattle-manure-compost (CMC) based activated carbons on the adsorptive removal of copper ions from aqueous solution. Degassing temperatures were 500℃, 800℃ and 1000℃. Activated carbons were characterized according to surface chemistry and pore structures. Adsorption of copper ions was carried out using the conventional bottle-point technique to which the equilibrium data were correlated to Langmuir and Freundlich models. Results indicated that the uptake of copper ions could be well characterized by Langmuir model. It was found that the adsorption of copper ions decreased with significant decrease in surface area as a result of helium degassing at higher temperature. The increase of electron density on graphene layers offered higher affinity towards copper ions at lower equilibrium concentration. It was inferred that copper ions favorably adsorbed on mesopores at lower equilibrium concentration and switched to micropores at higher equilibrium concentration.
文摘The warming of Antarctica observed in recent years is one of the consequences of deep degassing associated with the northward drift of the Earth’s core. Ascending streams of hydrogen and other gases move along the tectonic faults of the lithosphere. When they get into an oxidizing environment, there is an increase in the amount of water in the ocean and air, which is accompanied by a decrease in oxygen concentrations and the release of huge amounts of energy. The provisions of the proposed theory were tested using the method of mental critical experiment. The reality of atmospheric effects of subsurface degassing is confirmed by the facts of synchronous destruction of ozone in the stratosphere and an increase in the temperature of the surface air layer. These events usually coincide with releases of ozone-depleting and heat-generating hydrogen from the subsurface.
