Floating-Roof Tank Heel Reduction Options and Heel Turnover Emissions

1998 ◽  
Author(s):  
Terry A. Gallagher ◽  
Royce J. Laverman ◽  
Christian R. Desjardins
Keyword(s):  
Cross Contamination ◽  
Working Capacity ◽  
Operating Level ◽  
Valuable Product ◽  
Product Inventory ◽  
Minimum Operating

The net working capacity of floating roof tanks is the product inventory that is stored between the maximum and minimum operating levels of the floating roof. The product that remains in the tank when the floating roof is at its minimum operating level is residual inventory, referred to as the product heel. This trapped inventory is a valuable product asset that is not part of the tank net working capacity. This paper describes considerations that must be made when lowering the minimum operating level of floating roofs, both for new and retrofit tank applications, and presents methods of achieving these improvements. Some tank turnover operations require that the floating roof be landed and the tank drained dry. Tank turnover operations include those where it is important to avoid cross contamination of products. Recent studies have shown the importance of the emissions that occur during heel turnover operations. This paper describes a method for determining the heel turnover emissions and presents abatement options for controlling these emissions.

scholarly journals Beyond the implications of Grand Ethiopian Renaissance Dam filling policies

2021 ◽  
Vol 7 (3) ◽  
pp. 313-330
Author(s):  
Abay Yimere ◽  
◽  
Engdawork Assefa ◽  
Keyword(s):  
Time Series Data ◽  
Water Levels ◽  
Series Data ◽  
Future Climate Change ◽  
Policy Debate ◽  
International Treaty ◽  
Term Operation ◽  
Operating Level ◽  
Minimum Operating

<abstract> <p>The Grand Ethiopian Renaissance Dam (GERD) in Ethiopia and High Aswan Dam (HAD) in Egypt both operate on the Nile River, independent of a governing international treaty or agreement. As a result, the construction of the GERD, the Earth's eighth largest dam, ignited a furious debate among Ethiopia, Sudan, and Egypt on its filling policies and long-term operation. Ethiopia and Egypt's stance on the Nile River's water resources, combined with a nationalistic policy debate on the GERD's filling policies and long-term operation, has severely affected progress toward reaching agreeable terms before the first round of GERD filling was completed. These three countries continue to debate on the terms of agreement for the second round of GERD filling, scheduled to start by July 2021. We examined the GERD filling strategy for five- and six-year terms using time series data for the periods 1979–1987 and 1987–1992 to combine analyses for dry and wet seasons and investigate the potential impacts of filling the GERD above the downstream HAD using four HAD starting water levels. A model calibrated using MIKE Hydro results shows that during both five- and six-year terms of future GERD filling, Egypt would not need to invoke the HAD's minimum operating level. We pursued a narrative approach that appeals to both a technical and non-technical readership, and our results show the urgent need for cooperation at both policy and technical levels to mitigate and adapt to future climate change through the development of climate-proof agreements. Moreover, the results call for the riparian countries to move away from the current nationalistic policy debate approach and pursue a more cooperative, economically beneficial, and climate adaptive approach.</p> </abstract>

Design of a Practical Controller for a Commercial Scale Fossil Power Plant

1979 ◽  
Vol 101 (4) ◽  
pp. 284-289 ◽  
Author(s):  
Asok Ray ◽  
D. A. Berkowitz
Keyword(s):  
Rate Of Change ◽  
Normal Operation ◽  
Generation System ◽  
System A ◽  
Operating Level ◽  
Flash Tank ◽  
Load Rate ◽  
Power Generation System ◽  
Fossil Power Plant ◽  
Minimum Operating

To design an improved fuel controller for an operating, 386 MW(e), oil-fired power generation system, a mathematical model of the plant was developed from fundamental principles to predict thermal-hydraulic transients. This controller was successfully implemented in the actual plant by replacing a portion of the original control system. It was shown that the resulting minimum operating level of the system could be reduced from 220 MW (e) to flash tank level of 130 MW(e), and the customary load rate of change during normal operation improved from approximately 2 MW/min to 9 MW/min. Operation of the plant on automatic dispatch was subsequently demonstrated.

scholarly journals The Evaluation of Failure Structure Condition with Plaxis Program on the Poso I Hydropower Barrage

2021 ◽  
Vol 930 (1) ◽  
pp. 012097
Author(s):  
L Prasetyorini ◽  
E N Cahya ◽  
R D Lufira
Keyword(s):  
Safety Factor ◽  
Water Pressure ◽  
Hydropower Station ◽  
Flood Level ◽  
Operating Level ◽  
Sliding Stability ◽  
Downstream Section ◽  
Empty Condition ◽  
Central Sulawesi ◽  
Minimum Operating

Abstract The Poso I Hydropower Station is located on the Poso River, at the downstream section of the Poso Lake in Central Sulawesi Province. At the weir site, the catchment area is 1906.30 km2, and the structures are designed for a 50 year return period. Flood discharge is 1456.50 m3/s, with the mean annual release being 127.85 m3/s. The total supply water level is 510.50m, and the minimum operating level is 506.00 m. The model uses an undistorted model with a scale of 1 to 60. The barrage needs to be reviewed for failure factors that are likely to occur similar to those used in potential failures in the construction of dams in general. The study was considered in three conditions: empty barrage condition, average level, and flood level. With the piping calculation method, the barrage used Lane and Bligh method. While the calculation of barrage sliding stability used Finite Element Method with Plaxis 2D program simulation got the safety factor at the empty condition and flood level. It is caused by water pressure at flood level conditions that influence barrage stability. Safety factor value exceeded permits made. The Poso I Hydropower Station was safe.

Restorative dental treatment in times of COVID-19

2020 ◽  
Vol 68 ◽  
Author(s):  
Robson de Lima GOMES ◽  
Marlus da Silva PEDROSA ◽  
Claudio Heliomar Vicente da SILVA
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Dental Treatment ◽  
Close Contact ◽  
Cross Contamination ◽  
Clinical Protocols ◽  
Know How ◽  
Dental Procedures ◽  
Dental Staff ◽  
Dental Professional ◽  
Restrictive Measures

ABSTRACT Since the outbreak of the Coronavirus Disease 2019 (COVID-19), caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), numerous restrictive measures have been adopted by governments of different countries. The return to elective dental care in Brazil is a reality even during the COVID-19 pandemic. During restorative dental procedures, the dental professional requires close contact with the patient, being exposed to contaminated saliva and fluids. In addition, transmission of COVID-19 by the generation of aerosol produced by dental handipieces may be possible. Thus, the dental staff must know how to act during restorative dental procedures, putting into practice the correct clinical protocols to avoid cross-contamination and COVID-19 spread. The purpose of this article is to review the literature on the biosafety practices especially in the context of restorative dental procedures in times of COVID-19.

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