PYROLYSIS OF THE LOWER PARAFFINS: II. THE PRODUCTION OF OLEFINES IN BAFFLED QUARTZ TUBES

1933 ◽  
Vol 9 (2) ◽  
pp. 175-196 ◽  
Author(s):  
Adrien Cambron ◽  
Colin H. Bayley
Keyword(s):  
High Temperature ◽  
Turbulent Flow ◽  
Gas Flow ◽  
Side Reactions ◽  
Open Tube ◽  
High Degree ◽  
Quartz Tubes

The pyrolysis of the lower paraffins in externally heated quartz tubes has been studied under conditions of streamline and turbulent flow. It has been found possible to produce a high degree of turbulence in the flow of paraffin gases through tubes heated to a high temperature. It has been shown that when the pyrolysis is carried out under conditions of turbulent flow the yields of olefines obtained at a given temperature are greatly increased over those obtained in an open tube. It is further shown that under conditions of turbulent flow higher rates of conversion of the lower paraffins to olefines are possible since the temperatures at which side reactions begin to be noticeable are considerably higher under the above conditions than when the gas flow is streamline.

DISPERSED PHASE VELOCITY IN A HIGH-TEMPERATURE GAS FLOW

2019 ◽  
Vol 23 (4) ◽  
pp. 319-328
Author(s):  
Dmitry V. Nesterovich ◽  
Oleg G. Penyazkov ◽  
Yu. A. Stankevich ◽  
M. S. Tretyak ◽  
Vladimir V. Chuprasov ◽  
...  
Keyword(s):  
High Temperature ◽  
Phase Velocity ◽  
Gas Flow ◽  
Dispersed Phase ◽  
High Temperature Gas

Passive Auto-Focus Algorithm for Correcting Image Distortions Caused by Gas Flow in High-Temperature Measurements of Surface Phenomena

2012 ◽  
Vol 17 (4) ◽  
pp. 379-384 ◽  
Author(s):  
Krzysztof Strzecha ◽  
Tomasz Koszmider ◽  
Damian Zarębski ◽  
Wojciech Łobodziński
Keyword(s):  
High Temperature ◽  
Gas Flow ◽  
Temperature Measurements ◽  
Surface Phenomena ◽  
Auto Focus ◽  
High Temperature Measurements

Abstract In this paper, a case-study of the auto-focus algorithm for correcting image distortions caused by gas flow in high-temperature measurements of surface phenomena is presented. This article shows results of proposed algorithm and methods for increasing its accuracy.

REMANIT 4509

Alloy Digest ◽  
1995 ◽  
Vol 44 (9) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Exhaust System ◽  
Heat Treating ◽  
Exhaust Gas ◽  
Gas Purification ◽  
Temperature Performance ◽  
Scale Resistance ◽  
High Degree

Abstract REMANIT 4509 was developed specially for silencers and exhaust gas purification plants. Due to its composition, this steel exhibits scale resistance up to 950 C and a high degree of corrosion resistance to the gases occurring in the exhaust system. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-613. Producer or source: Thyssen Stahl AG.

PEERLESS LCT2

Alloy Digest ◽  
1963 ◽  
Vol 12 (11) ◽  
Keyword(s):  
Fracture Toughness ◽  
High Temperature ◽  
Elevated Temperatures ◽  
Heat Treating ◽  
High Heat ◽  
High Heat Resistance ◽  
Steel Company ◽  
Temperature Performance ◽  
Crucible Steel ◽  
High Degree

Abstract PEERLESS LCT2 is a hot work steel which possesses high heat resistance and a high degree of working hardness at elevated temperatures. This steel is best applied where hardness and resistance to abrasion are of more importance than toughness. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, and machining. Filing Code: TS-140. Producer or source: Crucible Steel Company of America.

Comparative Study of GaN Growth Process by MOVPE

1999 ◽  
Vol 572 ◽  
Author(s):  
Jingxi Sun ◽  
J. M. Redwing ◽  
T. F. Kuech
Keyword(s):  
High Temperature ◽  
Comparative Study ◽  
Gas Phase ◽  
Residence Time ◽  
Gas Flow ◽  
Flow Sheet ◽  
Flow Zone ◽  
High Quality ◽  
Phase Temperature ◽  
High Temperature Gas

ABSTRACTA comparative study of two different MOVPE reactors used for GaN growth is presented. Computational fluid dynamics (CFD) was used to determine common gas phase and fluid flow behaviors within these reactors. This paper focuses on the common thermal fluid features of these two MOVPE reactors with different geometries and operating pressures that can grow device-quality GaN-based materials. Our study clearly shows that several growth conditions must be achieved in order to grow high quality GaN materials. The high-temperature gas flow zone must be limited to a very thin flow sheet above the susceptor, while the bulk gas phase temperature must be very low to prevent extensive pre-deposition reactions. These conditions lead to higher growth rates and improved material quality. A certain range of gas flow velocity inside the high-temperature gas flow zone is also required in order to minimize the residence time and improve the growth uniformity. These conditions can be achieved by the use of either a novel reactor structure such as a two-flow approach or by specific flow conditions. The quantitative ranges of flow velocities, gas phase temperature, and residence time required in these reactors to achieve high quality material and uniform growth are given.

High Temperature Stability of MGCs Gas Turbine Components in Air and Combustion Gas Flow Environments

2004 ◽  
Author(s):  
Narihito Nakagawa ◽  
Hideki Ohtsubo ◽  
Kohji Shibata ◽  
Atsuyuki Mitani ◽  
Kazutoshi Shimizu ◽  
...  
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Gas Flow ◽  
Temperature Stability ◽  
High Temperature Strength ◽  
High Temperature Stability ◽  
Combustion Gas ◽  
Air Atmosphere ◽  
Low Nox Emission ◽  
Very High

Melt growth composites (MGCs) have a unique microstructure, in which continuous networks of single-crystal phases interpenetrate without grain boundaries. Therefore, the MGCs have excellent high-temperature strength characteristics, creep resistance, oxidation resistance and thermal stability in an air atmosphere at very high temperature. To achieve ultra-high thermal efficiency and low NOx emission for gas turbine systems, non-cooled turbine nozzle vanes and heat shield panels of combustor liners has been fabricated on an experimental basis. These components are thermally stable after heat treatment at 1700°C for 1000 hours in an air atmosphere. In addition, we have just started the exposure tests to evaluate the influence of combustion gas flow environment on MGCs.

scholarly journals High-temperature volcanic gas flow from the summit lava dome of Tarumai Volcano, Hokkaido, Japan

2013 ◽  
Vol 119 (7) ◽  
pp. V-VI
Author(s):  
Takeshi Hasegawa ◽  
Jun'ichi Miyamura ◽  
Yuji Fushiya ◽  
Yuji Takahashi
Keyword(s):  
High Temperature ◽  
Gas Flow ◽  
Lava Dome ◽  
Volcanic Gas

scholarly journals A crystallographic study of crystalline casts and pseudomorphs from the 3.5 Ga Dresser Formation, Pilbara Craton (Australia)

2018 ◽  
Vol 51 (4) ◽  
pp. 1050-1058 ◽  
Author(s):  
Fermin Otálora ◽  
A. Mazurier ◽  
J. M. Garcia-Ruiz ◽  
M. J. Van Kranendonk ◽  
E. Kotopoulou ◽  
...  
Keyword(s):  
High Temperature ◽  
Geological History ◽  
X Ray Diffraction ◽  
Mineral Phase ◽  
X Ray ◽  
Crystallographic Study ◽  
History Of ◽  
Degree Of Confidence ◽  
High Degree ◽  
Pilbara Craton

Crystallography has a long history of providing knowledge and methods for applications in other disciplines. The identification of minerals using X-ray diffraction is one of the most important contributions of crystallography to earth sciences. However, when the crystal itself has been dissolved, replaced or deeply modified during the geological history of the rocks, diffraction information is not available. Instead, the morphology of the crystal cast provides the only crystallographic information on the original mineral phase and the environment of crystal growth. This article reports an investigation of crystal pseudomorphs and crystal casts found in a carbonate-chert facies from the 3.48 Ga-old Dresser Formation (Pilbara Craton, Australia), considered to host some of the oldest remnants of life. A combination of X-ray microtomography, energy-dispersive X-ray spectroscopy and crystallographic methods has been used to reveal the original phases of these Archean pseudomorphs. It is found with a high degree of confidence that the original crystals forming in Archean times were hollow aragonite, the high-temperature polymorphs of calcium carbonate, rather than other possible alternatives such as gypsum (CaSO4·2H20) and nahcolite (NaHCO3). The methodology used is described in detail.

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