scholarly journals Analisis Pengujian Dry Gas Seal Type 28AT Tandem untuk Meningkatkan Reliability Dry Gas Seal di Kompresor Setrifugal

2019 ◽  
Vol 13 (2) ◽  
pp. 73
Author(s):  
Nuradi Bin Raswin
Keyword(s):  
Dynamic Testing ◽  
Testing Procedure ◽  
Health Check ◽  
The Other ◽  
Maximum Speed ◽  
Severe Damage ◽  
Test Rig ◽  
Dry Gas Seal ◽  
Operation And Maintenance ◽  
Gas Seals

Dry gas seal testing is one of the stages in the repair and maintenance of dry gas seals because without testing dry gas seals will have fatal consequences, which can cause more severe damage to the compressor and repair of humans and the environment. In the operation and maintenance of centrifugal compressors, especially gas compressors, there is often damage to dry gas seals or even if they are not damaged dry gas seals must be kept in a health check so that they can be used optimally and their reliability can be improved. In conducting a health check or repairing dry gas seal, one of the determinants of success is through static and dynamic testing using the DGS test rig or the other. Therefore it is very important in testing this dry gas seal that the author tries to learn how to complete the tests that must be considered in the testing procedure. In this study it can be concluded that the maximum speed used reaches 11429 rpm, when compared to the procedure is 1 - 1,225 x rpm in the compressor then the rotation obtained according to the procedure is (1,225 x 10000 = 12250 rpm maximum), with conditions 11429 rpm already fulfilling standard and is still within tolerance of testing rounds.

Study on the Thermo-Hydrodynamic of a Dry Gas Seal in Helium Circulator for High Temperature Gas-Cooled Reactor

2011 ◽  
Author(s):  
Jianshu Lin ◽  
Hong Wang
Keyword(s):  
High Temperature ◽  
Film Flow ◽  
Three Dimensional ◽  
Maximum Temperature ◽  
Analysis Method ◽  
Dry Gas Seal ◽  
Safety Requirements ◽  
Simulation Results ◽  
Gas Seals ◽  
High Temperature Gas

A comprehensive analysis method is proposed to resolve the problem of simulating a complex thermo-flow with two kinds of distinct characteristic length in the dry gas seal, and a conjugated simulation of the complicated heat transfer and the gas film flow is carried out by using the commercial CFD software CFX. By using the proposed method, a three dimensional of velocity and pressure field in the gas film flow and the temperature distribution within the sealing rings are investigated for three kinds of film thickness, respectively. A comparison of thermo-hydrodynamics of the dry gas seals is conducted between the sealed gas of air and helium. The latter one is used in a helium circulator for High Temperature Gas-cooled Reactor (HTGR). From comparisons and discussions of a series of simulation results, it will be found that the comprehensive proposal is effective and simulation results are reasonable, and the maximum temperature rise in the dry gas seal is within the acceptable range of HTGR safety requirements.

scholarly journals Dynamic testing of below-knee prosthesis: Assembly and components

1987 ◽  
Vol 11 (3) ◽  
pp. 117-123 ◽  
Author(s):  
H. W. Wevers ◽  
J. P. Durance
Keyword(s):  
Failure Mechanism ◽  
Lower Limb ◽  
Structural Component ◽  
Dynamic Testing ◽  
Knee Prosthesis ◽  
Axial Loading ◽  
The Other ◽  
Normal Gait ◽  
Component Failures ◽  
Lower Limb Amputees

Prosthetic assemblies for lower limb amputees are highly engineered and consist of several components each with its own failure mechanism. This paper describes the dynamic testing of HDPE rotational moulded sockets in a specially designed machine which mimics normal gait. Thus the components are subjected to all main loadings occurring during a stride such as axial loading and A-P bending about the knee and ankle. Machine details as well as the other components of the system are described. SACH feet appear to be vulnerable by rapid wear and structural component failures at less than 100,000 cycles were observed. The sockets are much less vulnerable and stand up to simulated loading of 1350 N for approximately 400,000 cycles. Metal components such as the foot bolt may also fail in fatigue if not properly tightened. References to proposed ISO standards are also included.

The influence of 3-DOF film thickness disturbance on transient performance of typical spiral groove dry gas seals

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yuan Chen ◽  
Hao Shang ◽  
Xiaolu Li ◽  
Yuntang Li ◽  
Bingqing Wang ◽  
...  
Keyword(s):  
Film Thickness ◽  
Degrees Of Freedom ◽  
Thickness Distribution ◽  
Transient Performance ◽  
Spiral Groove ◽  
Double Row ◽  
Content Type ◽  
Dry Gas Seal ◽  
Sealing Performance ◽  
Gas Seals

Purpose The purpose of this paper is to investigate the influence rule and mechanism of three degrees of freedom film thickness disturbance on the transient performance of spiral groove, upstream pumping spiral groove dry gas seal (UP-SDGS) and double-row spiral groove dry gas seal (DR-SDGS). Design/methodology/approach The transient performance of spiral groove, UP-SDGS and DR-SDGS are obtained by solving the transient Reynolds equation under different axial and angular disturbance coefficients. The transient and steady performance of the above-mentioned DGSs are compared and analyzed. Findings The film thickness disturbance has a remarkable impact on the sealing performance of DGS with different structures and the calculation deviations of the leakage rate of the UP-DGS will increase significantly if the film thickness disturbance is ignored. The axial and angular disturbance jointly affect the film thickness distribution of DGS, but there is no significant interaction between them on the transient sealing performance. Originality/value The influence mechanism of axial disturbance and angular disturbance on the transient performance of typical SDGSs behavior has been explained by theory. Considering small and large disturbance, the interaction between axial disturbance and angular disturbance on the transient performance have been studied.

Reparations for Children and Youth

2016 ◽  
pp. 307-328
Author(s):  
Sinthya Rubio Escolar
Keyword(s):  
Transitional Justice ◽  
Armed Conflict ◽  
The Other ◽  
Children And Youth ◽  
Severe Damage ◽  
Violence Against Children ◽  
Other Hand ◽  
Political Project

Violence against children and youth in war causes severe damage to individuals, communities and societies. This chapter aims to demonstrate the importance of reparations for children and youth as a peacebuilding mechanism in the context of transitional justice. On one hand, the chapter seeks to address reparations for children and youth understood as a political project, with a transformative and participatory potential for rebuilding societies and healing the wounds of those who have been affected by armed conflict. On the other hand, the paper attempts to overcome the conception of children and youth as passive victims, providing them with agency to become engaged political members in building peaceful societies. Thus, reparations should position them as subjects of rights, giving them voice as contributors in peacebuilding processes.

A Technique for the Detection of Liquid Slip at a Load-Bearing, High Shear Contact

2005 ◽  
Author(s):  
J. H. Choo ◽  
H. A. Spikes ◽  
M. Ratoi ◽  
R. P. Glovnea ◽  
A. Forrest
Keyword(s):  
High Speed ◽  
Physical Phenomenon ◽  
Solid Surfaces ◽  
The Other ◽  
Plasma Cleaning ◽  
High Shear ◽  
Test Rig ◽  
Simple Liquids ◽  
New Type ◽  
O2 Plasma

This research aims to exploit the physical phenomenon of simple liquids slipping against very smooth solid surfaces, to create a new type of bearing where the lubricant slips against one surface but not the other. To demonstrate the feasibility of this idea, a special test rig capable of measuring milli-Newton forces has been employed to measure friction in high-speed, sliding contacts between a steel roller and sapphire window, lubricated by hexadecane. Sapphire was made either lyophobic by coating with a self-assembled silane monolayer, or lyophilic by O2-plasma cleaning. The roller was made lyophilic. A significant reduction in friction was achieved with lyophobic sapphire but not with lyophilic sapphire. This reduced friction is believed to result from lubricant slip against the lyophobic surface. One possible application of such a bearing will be in microsystems and devices.

scholarly journals Application of Thermoelectric Modules as Renewable Energy Sources

2018 ◽  
Vol 12 (3) ◽  
pp. 151-158
Author(s):  
Ivan Šumiga ◽  
Živko Kondić
Keyword(s):  
Current Flow ◽  
Renewable Energy Sources ◽  
The Other ◽  
Energy Sources ◽  
Experimental Measurements ◽  
Thermoelectric Generators ◽  
Thermoelectric Modules ◽  
Operation And Maintenance ◽  
Flow Through ◽  
Current Flows

Thermoelectric modules are used for heating or cooling if an electric current flows through them. If one side of such a module is heated and the other side is cooled, the outputs show a potential difference that creates the current flow through an enclosed circuit. The paper describes briefly the physical basis of the operation of semiconductor thermoelectric modules and their application for generating electricity as thermoelectric generators. The experimental measurements were made with different available modules of thermoelectric generators. The analysis of obtained results has provided the conclusions about the possibility of their application as sources of electricity. Although the efficiency of thermoelectric modules is still quite low, the latest research reveals the possibility of the use of materials that make modules more efficient. Considering the fact that they do not contain moving parts, they are characterized by reliable, long-lasting work and simple operation and maintenance.

Dynamic testing of a corrugated steel arch bridge

2008 ◽  
Vol 35 (3) ◽  
pp. 246-257 ◽  
Author(s):  
Zbigniew Manko ◽  
Damian Beben
Keyword(s):  
Vibration Frequency ◽  
Dynamic Load ◽  
Critical Speed ◽  
Dynamic Testing ◽  
The Other ◽  
Steel Plates ◽  
Highway Bridge ◽  
Dynamic Coefficients ◽  
Bridge Structures ◽  
Load Tests

The paper presents the results and conclusions of dynamic load tests that were conducted on a highway bridge over the Gimån River in Sweden made of Super Cor corrugated steel plates (CSP), the first bridge of this type in Scandinavia. The critical speed magnitudes, dynamic coefficients, velocity vibration, and vibration frequency are determined in the paper. Conclusions drawn from the tests can be most helpful in the assessment of the behaviour of this type of corrugated plate – soil bridge. In consideration of the application of this type of structure in the case of small-to-medium span bridges, the conclusions from this research cannot yet be generalized to all types of such solutions. The application details with respect to all types of such bridge structures would require additional analysis (field and model tests and calculations) on the other types of soil–steel bridges.

Influence of Gas Feeding Position on the Performance of Radial-Inflow Hydrostatic Gas Ultra-Short Journal Bearings

2016 ◽  
Author(s):  
Chao Nie ◽  
Xiaojun Yan ◽  
Xia Chen
Keyword(s):  
Rotational Speed ◽  
Cfd Simulation ◽  
Journal Bearing ◽  
Maximum Speed ◽  
Test Rig ◽  
Thrust Bearings ◽  
Axial Stability ◽  
Speed Measurement ◽  
Gas Leaks ◽  
Better Than

To investigate the influence of gas feeding position on the performance of radial-inflow hydrostatic gas ultra-short (with a L/D value as 0.1) journal bearing two rotor-bearing system test rigs with two different feeding positions (central feeding and bottom feeding) for the journal bearing were designed. A rotor measurement system with an original rotational speed measurement program is built. Rotation experiments to measure the maximum rotational speed of rotors under different inlet pressure of journal bearing were conducted. It was found that, the rotor supported by the central feeding journal bearing worked better, and achieved a maximum rotational speed of 40000 rpm, (83.74m/s for the tip speed). While the test rig with bottom feeding journal bearing could not function well. To verify the reasons behind the failure mentioned above, the flow condition in the journal clearance and the rotor bottom clearance was analyzed by the CFD simulation. It shows that most of the journal bearing gas “leaks” into the rotor bottom clearance in the bottom feeding bearing test rig, disarranging the axial stability of the rotor and the normal functioning of the thrust bearings. In conclusion, the central feeding radial-inflow journal bearing is better than the bottom feeding one, for the better operability and higher maximum speed. And an ideal feeding position is supposed to make the journal bearing does not influence the axial stability of the rotor and the functioning of the thrust bearings.

Sign in / Sign up

Export Citation Format

Share Document