Mathematical Modeling and Program Implementation of Gasdynamic Solution of Dry Gas Seals for Centrifugal Compressors

2020 ◽  
pp. 591-602
Author(s):  
Lyudmyla Rozova ◽  
Gennadii Martynenko
Keyword(s):  
Mathematical Modeling ◽  
Program Implementation ◽  
Centrifugal Compressors ◽  
Gas Seals

Experience in Full-Load Testing of Natural Gas Centrifugal Compressors for Rotordynamics Improvements

1997 ◽  
Vol 119 (4) ◽  
pp. 934-941 ◽  
Author(s):  
A. Gelin ◽  
J.-M. Pugnet ◽  
D. Bolusset ◽  
P. Friez
Keyword(s):  
Natural Gas ◽  
Stability Limit ◽  
Rotating Stall ◽  
Low Flow ◽  
Load Testing ◽  
Centrifugal Compressors ◽  
High Rotational Speed ◽  
Full Load ◽  
Load Tests ◽  
Gas Seals

During full-load shop tests under natural gas, two multistage centrifugal compressors exhibited subsynchronous vibrations. Both of them are low-flow, high-pressure, high rotational speed compressors, and are fitted with tilting pad bearings and dry gas seals. A rotating stall problem was first eliminated by a modification of the diffuser geometry. Then, aerodynamic excitations caused the rotors to operate at their stability limit, and high vibration levels were observed at the first natural frequency. A complete rotordynamics analysis was performed in order to model precisely all the fluid–structure interactions. Modifications of the rotor designs were implemented, consisting in optimizing conveniently the bearing pads, replacing the toothed labyrinth seals of the balance pistons by damping honeycomb seals, fitting them with improved shunt hole systems. In addition, the dry gas seals were found to have been damaged, due to thermal effects, and further modifications were implemented to eliminate this problem. Final full load tests demonstrated a satisfactory behavior of both centrifugal compressors.

Paper 5: The Development of Centrifugal Gas Compressors for Process Plant Duty

1969 ◽  
Vol 184 (18) ◽  
pp. 45-53
Author(s):  
H. F. Ibbott
Keyword(s):  
Detailed Analysis ◽  
Centrifugal Compressor ◽  
Operating Conditions ◽  
Design Features ◽  
Centrifugal Compressors ◽  
Compressor Rotor ◽  
Process Plant ◽  
Full Speed ◽  
Process Plants ◽  
Gas Seals

This paper describes the various types of centrifugal compressor used in process plants, and continues to discuss the more important components of these compressors and particular design features which are required to overcome some difficult operational problems. Items of particular interest include a discussion on the latest form of compressor rotor construction, the techniques required for balancing a rotor at full speed, and a detailed analysis of shaft gas seals and problems that can arise with gas seals under certain operating conditions. The paper also describes such special subjects related to process plant compressors as compressor selection and design by utilization of computers, methods of reducing time to produce compressor orders by discrete stockholdings; types of driver and shaft couplings used for these machines, and test facilities employed for centrifugal compressors which can be utilized to reduce commissioning periods at site.

Economic Justification of Mechanical Dry Seals for Centrifugal Compressors

2000 ◽  
Author(s):  
John Sears ◽  
Derek Hosking
Keyword(s):  
Cost Savings ◽  
Economic Benefits ◽  
Environmental Drivers ◽  
Centrifugal Compressors ◽  
Potential Cost ◽  
Dry Gas Seal ◽  
Economic Justification ◽  
Gas Seals ◽  
The Cost ◽  
Basic Philosophy

This paper discusses an approach to calculate the economic justification for using mechanical dry seals in centrifugal compressors. This evaluation is based on the full dry gas seal system cost compared to the associated operational and maintenance savings over standard oil seal systems. The economic evaluation is applicable for both the retrofit of existing equipment and for the installation into new equipment. However, the focus of this paper is on the cost savings with respect to the dry gas seal retrofits. Although the economic justifications are shown for centrifugal compressors in pipeline and refinery services, the same basic philosophy can be used to evaluate the economic justification of dry gas seals for compressors in other types of service. Different areas of potential cost savings and environmental drivers are discussed, including a method calculating the associated savings. In addition, an example calculation for a specific compressor is presented. It must be emphasized that the economic benefits and the associated costs are highly dependent on the type and size of compressor as well as the particular application.

Experience in Full Load Testing Natural Gas Centrifugal Compressors for Rotordynamics Improvements

1996 ◽  
Author(s):  
Alain Gelin ◽  
Jean-Marc Pugnet ◽  
Daniel Bolusset ◽  
Patrick Friez
Keyword(s):  
Natural Gas ◽  
Stability Limit ◽  
Rotating Stall ◽  
Low Flow ◽  
Load Testing ◽  
Centrifugal Compressors ◽  
High Rotational Speed ◽  
Full Load ◽  
Load Tests ◽  
Gas Seals

During full load shop tests under natural gas, two multistage centrifugal compressors exhibited subsynchronous vibrations. Both of them are low flow, high pressure, high rotational speed compressors, and are fitted with tilting pad bearings, and dry gas seals. A rotating stall problem was firstly eliminated by a modification of the diffuser geometry. Then, aerodynamic excitations caused the rotors to operate at their stability limit, and high vibration levels were observed at the first natural frequency. A complete rotordynamics analysis was performed in order to model precisely all the fluid-structure interactions. Modifications of the rotor designs were implemented, consisting in optimizing conveniently the bearing pads, replacing the toothed labyrinth seals of the balance pistons by damping honeycomb seals, fitting them with improved shunt hole systems. In addition, the dry gas seals were found to have been damaged, due to thermal effects, and further modifications were implemented to eliminate this problem. Final full load tests demonstrated a satisfactory behaviour of both centrifugal compressors.

Communication Disordered: Program Implementation in Long-Term Care

2016 ◽  
Vol 1 (15) ◽  
pp. 64-67
Author(s):  
George Barnes ◽  
Joseph Salemi
Keyword(s):  
Program Implementation ◽  
Long Term Care ◽  
Family Satisfaction ◽  
Regulatory Compliance ◽  
Care Staff ◽  
Term Care ◽  
Staff Members ◽  
Change Policy

The organizational structure of long-term care (LTC) facilities often removes the rehab department from the interdisciplinary work culture, inhibiting the speech-language pathologist's (SLP's) communication with the facility administration and limiting the SLP's influence when implementing clinical programs. The SLP then is unable to change policy or monitor the actions of the care staff. When the SLP asks staff members to follow protocols not yet accepted by facility policy, staff may be unable to respond due to confusing or conflicting protocol. The SLP needs to involve members of the facility administration in the policy-making process in order to create successful clinical programs. The SLP must overcome communication barriers by understanding the needs of the administration to explain how staff compliance with clinical goals improves quality of care, regulatory compliance, and patient-family satisfaction, and has the potential to enhance revenue for the facility. By taking this approach, the SLP has a greater opportunity to increase safety, independence, and quality of life for patients who otherwise may not receive access to the appropriate services.

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