Stability of Smoke Layer Under Sprinkler Water Spray

2005 ◽  
Author(s):  
C. F. Zhang ◽  
R. Huo ◽  
Y. Z. Li ◽  
W. K. Chow
Keyword(s):  
Sprinkler System ◽  
Full Scale ◽  
Operating Pressure ◽  
Water Spray ◽  
Smoke Layer ◽  
The Stability

Stability of smoke layer induced by a fire will be studied in this paper. A series of full-scale burning tests were carried out to study the interaction of the hot smoke layer with a sprinkler water spray. A new rig was built to give a smoke layer. The results show that the stability of a smoke layer will be disturbed by the discharged water spray. The operating pressure of the sprinkler system is a key point. When the smoke layer lost its stability, the dragging force acting on the smoke layer was found to be less than the buoyancy.

Effect of Thermal Aging on Strain Capacity of X80 SAW Pipes

2012 ◽  
Author(s):  
Hidenori Shitamoto ◽  
Masahiko Hamada ◽  
Nobuaki Takahashi ◽  
Yuki Nishi
Keyword(s):  
Thermal Aging ◽  
Arc Welding ◽  
Submerged Arc Welding ◽  
Full Scale ◽  
Operating Pressure ◽  
Bending Tests ◽  
Strain Capacity ◽  
Submerged Arc ◽  
Pipe Bending

Application of API X80 grade line pipes has been promoted to increase the operating pressure. It is generally known that the deformability of submerged arc welding (SAW) pipes is decreased by increasing strength of the pipes. The assessment of the strain capacity of X80 SAW pipes is required for strain-based design (SBD). In the assessment of the strain capacity, one of the important issues is the effect of thermal aging during the anti-corrosion coating on the yielding phenomenon. In this study, full-scale pipe bending tests of X80 SAW pipes produced by UOE process were performed to evaluate the effect of thermal aging on the strain capacity.

scholarly journals Microbiota of anaerobic digesters in a full-scale wastewater treatment plant

2017 ◽  
Vol 43 (3) ◽  
pp. 53-60 ◽  
Author(s):  
Piotr Świątczak ◽  
Agnieszka Cydzik-Kwiatkowska ◽  
Paulina Rusanowska
Keyword(s):  
Microbial Community ◽  
Sewage Sludge ◽  
Methane Production ◽  
Treatment Plant ◽  
Full Scale ◽  
Successful Implementation ◽  
Anaerobic Digesters ◽  
Syntrophic Bacteria ◽  
The Stability ◽  
Microbial Groups

AbstractAnaerobic digestion is an important technology for the bio-based economy. The stability of the process is crucial for its successful implementation and depends on the structure and functional stability of the microbial community. In this study, the total microbial community was analyzed during mesophilic fermentation of sewage sludge in full-scale digesters.The digesters operated at 34–35°C, and a mixture of primary and excess sludge at a ratio of 2:1 was added to the digesters at 550 m3/d, for a sludge load of 0.054 m3/(m3·d). The amount and composition of biogas were determined. The microbial structure of the biomass from the digesters was investigated with use of next-generation sequencing.The percentage of methanogens in the biomass reached 21%, resulting in high quality biogas (over 61% methane content). The abundance of syntrophic bacteria was 4.47%, and stable methane production occurred at a Methanomicrobia to Synergistia ratio of 4.6:1.0. The two most numerous genera of methanogens (about 11% total) wereMethanosaetaandMethanolinea, indicating that, at the low substrate loading in the digester, the acetoclastic and hydrogenotrophic paths of methane production were equally important. The high abundance of the orderBacteroidetes, including the classCytophagia(11.6% of all sequences), indicated the high potential of the biomass for efficient degradation of lignocellulitic substances, and for degradation of protein and amino acids to acetate and ammonia.This study sheds light on the ecology of microbial groups that are involved in mesophilic fermentation in mature, stably-performing microbiota in full-scale reactors fed with sewage sludge under low substrate loading.

Experimental study on vertical rigid and flexible polyurethane fire suppression using water spray

2019 ◽  
pp. 089270571987918
Author(s):  
Hengze Zhao ◽  
Ye Li ◽  
Yipei Qi ◽  
Xuanmeng Dong ◽  
Yongming Zhang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Video Processing ◽  
Fire Suppression ◽  
Application Rate ◽  
Flame Height ◽  
Operating Pressure ◽  
Water Spray ◽  
Surface Cooling ◽  
Front Position ◽  
Flexible Polyurethane

A series of vertical fire suppression experiments on rigid polyurethane (RPU) and flexible polyurethane (FPU) with/without water spray were conducted in a standard chamber. A new video processing method was developed to determine the pyrolysis front position of wind-aided flame. Averaged flame height, carbon monoxide/hydrogen cyanide concentration, view factors, and extinguishing time were determined with operating pressure varying from 0.15 MPa to 0.4 MPa. The experimental study showed that water spray would suppress RPU/FPU fire mainly by fuel surface cooling. Furthermore, the perfect water spray pressure for RPU/FPU fire suppression was 0.3 MPa and the corresponding water application rate was 0.7511 mg/(cm2·s).

scholarly journals Nonlinear modeling and stability analysis of a pilot-operated valve-control hydraulic system

2018 ◽  
Vol 10 (11) ◽  
pp. 168781401881066 ◽  
Author(s):  
Wei Wei ◽  
Hongchao Jian ◽  
Qingdong Yan ◽  
Xiaomei Luo ◽  
Xuhong Wu
Keyword(s):  
Dynamic Model ◽  
Hydraulic System ◽  
Nonlinear Modeling ◽  
Orifice Diameter ◽  
Operating Pressure ◽  
Nonlinear Dynamic Model ◽  
System Parameters ◽  
Excited Vibration ◽  
The Stability ◽  
Valve Control

A nonlinear dynamic model is developed to analyze the stability of a pilot-operated valve-control hydraulic system. The dynamic model includes motion of the valve spool and fluid dynamics in the system. Characteristics such as pressure flow across the valve port and orifices, pressure, and flow rate in valve chambers are taken into consideration. Bifurcation analysis is proposed and examined by numerical simulation results when the feedback orifice diameter changes. The effects of different system parameters such as pilot-operating pressure, spring stiffness, and overlap of inlet port on the stability border of the system are studied by two-dimensional bifurcation analyses. The study identifies that bifurcation can occur in the system and lead to sustained self-excited vibration with parameters in certain region of the parameter space. It suggests that the vibration can be effectively predicted and prevented by selecting system parameters from the asymptotic stable parameter region.

Analysis, simulation, and implementation of a human-inspired pole climbing robot

Robotica ◽  
2011 ◽  
Vol 30 (2) ◽  
pp. 279-287 ◽  
Author(s):  
A. Sadeghi ◽  
H. Moradi ◽  
M. Nili Ahmadabadi
Keyword(s):  
Static Analysis ◽  
Full Scale ◽  
The Other ◽  
Light Weight ◽  
Simple Design ◽  
Climbing Robot ◽  
Full Size ◽  
Control Light ◽  
The Stability ◽  
Novel Design

SUMMARYIn this paper, we present the design, static analysis, simulation, and implementation of a novel design for a naturally stable climbing robot that has been inspired from human pole/tree climbers. The other benefits of this robot, besides being naturally stable, are its simple design, ease of control, light weight, simple mechanism, and fast climbing speed. The robot consists of three wheels, two free and one active wheel, which enable the robot to climb or descend poles. The free wheels are almost frictionless, while the active wheel has enough friction to be able to apply force on the pole for stable climbing or descending. The wheels are designed in V-shape such that the robot can compensate for misplacements eliminating possible detachment from poles. Although the robot can operate with a single free wheel, however, an extra free wheel is added to increase the stability and safety of the robot. In this paper, the static analysis of the robot is presented and the robot is simulated. Furthermore, the robot is actually implemented and successfully tested in two sizes, a small size and a big/full size. The full-scale prototype has been equipped with washing and inspection tools and tested washing actual street lights. The results show the unique characteristics of this robot that make it more stable if more weight is carried.

A full-scale stability experiment on a diaphragm wall trench

2000 ◽  
Vol 37 (2) ◽  
pp. 379-392 ◽  
Author(s):  
Jiin-Song Tsai ◽  
Lee-Der Jou ◽  
Hsii-Sheng Hsieh
Keyword(s):  
Full Scale ◽  
Failure Pattern ◽  
Diaphragm Wall ◽  
Lateral Deformation ◽  
Sandy Ground ◽  
Stability Experiment ◽  
Scale Field ◽  
Slurry Trench ◽  
Scale Experiment ◽  
The Stability

This paper presents the results of a full-scale field experiment on the stability of a slurry-filled diaphragm wall trench. The objective of this experiment was to observe the failure pattern of a slurry-supported trench excavated in sandy ground. Ground responses, including settlement and lateral deformation of the surrounding ground adjacent to the experimental trench, were carefully monitored during the experiment. The stability of the trench was examined by lowering the slurry level in stages. The trench was deliberately failed. Field observations indicated that the experimental trench failed in 2 h in a progressive sliding pattern that resulted in a near-hemispherical cave-in of the adjacent ground. In this paper, a failure mechanism of the trench is proposed and an analytical method is adopted to back-analyze the stability of the trench. The stability of the trench and the failure pattern can be accurately analyzed using the method of Tsai and Chang.Key words: full-scale experiment, field test, slurry trench, stability analysis.

Calculation of the stability of buried metal culverts full-scale experimental verification

1988 ◽  
Vol 6 (1) ◽  
pp. 65
Author(s):  
P. Habib ◽  
M.P. Luong ◽  
N.T. Long ◽  
G. Legeay ◽  
L. Baude
Keyword(s):  
Experimental Verification ◽  
Full Scale ◽  
The Stability

scholarly journals Full-Scale Fracture Propagation Experiments: A Recent Application and Future Use for the Pipeline Industry

2000 ◽  
Author(s):  
D. Michael Johnson ◽  
Peter S. Cumber ◽  
Norval Horner ◽  
Lorne Carlson ◽  
Robert Eiber
Keyword(s):  
Fracture Propagation ◽  
High Strength Steels ◽  
High Strength ◽  
Test Site ◽  
Full Scale ◽  
Operating Conditions ◽  
Test Facility ◽  
Operating Pressure ◽  
Experimental Facility ◽  
The Usa

A full scale fracture propagation test facility has been developed to validate the design, in terms of the ability of the material to avert a propagating fracture, of a major new pipeline to transport gas 1800 miles from British Columbia in Canada to Chicago in the USA. The pipeline, being built by Alliance Pipeline Ltd, will transport rich natural gas, i.e. gas with a higher than normal proportion of heavier hydrocarbons, at a maximum operating pressure of 12,000 kPa. This gas mixture and pressure combination imposes a more severe requirement on the pipe steel toughness than the traditional operating conditions of North American pipelines. As these conditions were outside the validated range of models, two full-scale experiments were conducted to prove the design. This paper will provide details of the construction of the 367m long experimental facility at the BG Technology Spadeadam test site along with the key data obtained from the experiments. Evaluation of this data showed that the test program had validated Alliance’s fracture control design. The decompression data obtained in the experiments will be compared against predictions from a new decompression model developed by BG Technology. The use of the experimental facility and the model to support future developments in the pipeline industry, particularly in relation to the use of high strength steels, will also be discussed.

Testing and Analysis of Steel Strip Reinforcement for Pipeline External Rehabilitation

2010 ◽  
Author(s):  
David J. Miles ◽  
Tim J. M. Bond ◽  
Raymond N. Burke ◽  
Ruben van Schalkwijk
Keyword(s):  
Steel Strip ◽  
New Technology ◽  
High Strength ◽  
Full Scale ◽  
Operating Conditions ◽  
Operating Pressure ◽  
Batch Tests ◽  
Girth Welds ◽  
The Individual ◽  
Pipeline Design

A new technology for external rehabilitation of pipelines, known as XHab™, has been developed. This method involves wrapping multiple layers of ultra-high strength steel strip (UHSS) in a helical form continuously over an extended length of pipeline using a dedicated forming and wrapping machine. The reinforcement afforded by the strip can be used to bring a defective section of pipe (e.g. externally corroded or dented) back to its original allowable operating conditions, or even to increase the allowable operating pressure if the desired operating conditions exceed the original pipeline design limits. This paper describes the full scale burst testing and analysis of defective pipes which have been repaired using the XHab process. The full scale test sections are 30″ × 0.5″ API 5L X52 DSAW pipe and include the following specimens: • Bare pipe with no defects; • Bare pipe with single machined defect; • Wrapped pipe with single machined defect and designed reinforcement; • Wrapped pipe with single machined defect and insufficient reinforcement; • Wrapped pipe with interacting defect array and designed reinforcement. The above full scale burst tests are supplemented by FEA models using ABAQUS. The material models for the steel pipe, UHSS strip, defect patch material and strip adhesive are based on measured data from the batch tests and tuned against the control burst test results. The structural behavior in the individual metallic and non-metallic elements can therefore be examined more closely, particularly in the region of the defect and where the wrapped strip crosses seam and girth welds.

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