Ground Tanks Research Articles

A Study on the Characteristics of Electronic MagneticInterference(EMI) in Acoustic Emission Testing forCorrosion Detection of Ground Tank

The evaluation and comparison have been made for the EMI noise which was included in the signal from the sensors in the acoustic emission testing for the bottom plate of ground tank at full. The EMI signal has been classified into two types. One is the signal with very short AE count, and this signal possibly can be filtered by front end filter setting of the channel count with low level of 4 and high level of <TEX>$10^8$</TEX>. The other EMI signal occurred from CH 1, CH 3 and CH 10, and had high and constant duration with high energy and count (maximun duration > <TEX>$10^5\;{\mu}s$</TEX>), and has characteristic gradient of accumulation amplitude distribution. This signal should be removed in the AE signal evaluation by filtering, because this may affect to the total gradient.

Pupal-productivity surveys to identify the key container habitats ofAedes aegypti(L.) in Barranquilla, the principal seaport of Colombia

Surveys were conducted in three neighbourhoods of Barranquilla, the main seaport of Colombia, to identify, using counts of pupae in water containers during the wet and dry seasons, the most productive Aedes aegypti breeding sites. Overall, 3,433 premises were investigated in the wet season and 3,563 in the dry, representing, respectively, 82.3% and 84.6% of the total numbers of premises in the study areas. Despite a reasonably reliable supply of piped water, there were still some large storage containers for domestic water (cement ground tanks and plastic, metal and cement drums) in the area. Although such containers represented only 1.8%-16.3% of the total number of containers observed, they contributed 72.0%-78.2% and 65.0%-95.8% of the total Ae. aegypti pupal population in the three study neighbourhoods during the wet and dry seasons, respectively. In contrast, bottles represented 23.0%-88.9% of the total number of containers but produced no more than 0.1% of the total Ae aegypti pupal populations in these neighbourhoods. Other containers (tyres, vases, 'other discarded' and 'other used') generally produced only low numbers of pupae. In some settings, however, containers in the 'other discarded' category could contribute up to 19% of the total pupal population, and in one survey of one neighbourhood a single container in this category held 9.1% of all the pupae collected. These results, from a city where dengue fever is endemic, will help to focus local campaigns for Ae. aegypti source-reduction on the most productive categories of container.

石油タンク底板裏面の腐食管理と寿命予測

石油タンク底板裏面の腐食管理と寿命予測

Critical sizes of ground and underground horizontal cylindrical tanks

The paper deals with ground and underground horizontal cylindrical tanks supported at both ends. The ground tanks are loaded with internal hydrostatic pressure and small negative pressure. On the other hand, the underground tanks are located in water containing soil and loaded with external hydrostatic pressure. Critical states of both structures are determined based on solving the equation of stability of cylindrical shell. The problem so defined has been converted to calculation of critical thicknesses of walls for the family of circular cylindrical tanks of different capacities. Critical sizes of the structures have been determined as functions of dimensionless critical thickness and dimensionless tank length.

液体水素輸送・貯蔵技術の開発

The Japan hydrogen project, WE-NET (World Energy Network), has shown that high-density LH2 (liquid hydrogen) is the most promising medium for transporting and storing large-mass hydrogen efficiently and economically. In the future, large-mass liquid hydrogen storage technology for ground tanks and ocean tankers will be needed, and the commercial scale may be the same as existing LNG storage systems, which have a storage capacity of several hundreds of thousands of cubic meters. The conceptual designs of 200,000 m3 LH2 tankers and 50,000 m3 LH2 ground tanks were studied in WE-NET Phase I (1993-1998). This study has concluded that the optimized thermal insulation structure for a large storage tank should be developed. Therefore, in Phase II of WE-NET (1999-2002), we tested the thermal conductance and cryogenic compressive strengths of insulation materials in order to develop various insulation structures. Their conceptual designs were reviewed by analyzing experimental results. To realize the government target of introducing 50,000 fuel-cell vehicles by 2010 and 5 million vehicles by 2020, a hydrogen supply infrastructure must be constructed. Since LH2 is applicable for the hydrogen infrastructure, we have developed a high-performance LH2 container, a key component of the system. This paper describes the conceptual designs of LH2 tankers and LH2 ground tanks, elementary tests of various insulations, and also the LH2 infrastructure for fuel-cell vehicles.

Impact of environmental conditions on sub-surface storage tanks (part I)

The present investigation concentrates on the effects of environmental changes upon sub-surface storage tanks that are frequently used in the Niger Delta region and other parts of Nigeria for petroleum products. The research is part one of a long-term study that aims at the determination of corrosion rates of the under ground tanks within the Port Harcourt Municipality. Cast iron made storage tanks with gasoline fluid were buried under the soil at a depth of 4 m under various environment conditions. The simulated conditions include natural rain fail, temperature and acidic, alkaline and neutral soils. A control condition of neutral sea sand as base and filling materials were also investigated. After various exposure periods, the densities of the storage tanks, composition of soil, soil pH, corrosion rates and soil resistivities were determined. The experiments were repeated after every six months. Within the last three years, it has been observed that the corrosion rates of the tanks covered with cellophane materials were relatively less than those tanks that were buried directly within the soil except that of the control experiment. In addition the corrosion rates of tanks buried within the acidic environment were more than those buried within the alkaline and neutral soil conditions. Also, it was interestingly observed that the corrosion rates were generally and initially very rapid during the first year of the work, and decreased with time. Equally the water content of the soil was low. The soil resistivity increased relatively to the control sample site (G). (Journal of Applied Sciences & Environmental Management: 2002 6(2):79-84)

Study on Characteristics of Sea-shock Response of Floating Structure Considering the Reflection Characteristics of Earthquake Waves

The objective of present paper is to examine the characteristics of sea-shock responses of floating structures by using practical method (so call impedance method) considering the effect of seabed. In the present paper, the impedance method, which was considered the reflection characteristics of earthquake wave by using impedance ratio, was formulated and the characteristics of hydrodynamic forces by present method was compared with the results by the method of elastic sea ground and wave tank experiments and evaluation method of optimum impedance ratio was discussed.Furthermore, the characteristics for sea-shock response of floating structure were calculated by the impedance method with optimum impedance ratio and also these numerical results were discussed.

Development of transport and storage technologies for large mass liquid hydrogen

The Japan hydrogen project, WE-NET (World Energy Network), has shown that high-density LH2 (liquid hydrogen) is the most promising medium for transporting and storing large-mass hydrogen efficiently and economically. In the future, large-mass liquid hydrogen storage technology for ground tanks and ocean tankers will be needed, and the commercial scale may be the same as existing LNG storage systems, which have a storage capacity of several hundreds of thousands of cubic meters. The conceptual designs of 200,000 m3 LH2 tankers and 50,000 m3 LH2 ground tanks were studied in WE-NET Phase I (1993-1998). This study has concluded that the optimized thermal insulation structure for a large storage tank should be developed. Therefore, in Phase II of WE-NET (1999-2002), we tested the thermal conductance and cryogenic compressive strengths of insulation materials in order to develop various insulation structures. Their conceptual designs were reviewed by analyzing experimental results. To realize the government target of introducing 50,000 fuel-cell vehicles by 2010 and 5 million vehicles by 2020, a hydrogen supply infrastructure must be constructed. Since LH2 is applicable for the hydrogen infrastructure, we have developed a high-performance LH2 container, a key component of the system. This paper describes the conceptual designs of LH2 tankers and LH2 ground tanks, elementary tests of various insulations, and also the LH2 infrastructure for fuel-cell vehicles.

液体水素貯槽用断熱性能試験装置の開発

In the Japanese hydrogen project, World Energy Network (WE-NET) for realizing reusable clean energy systems using hydrogen, conceptual designs of large-mass liquid hydrogen storage systems for ground and transportation tanks have been studied. For completing such large storage systems, of which scales would reach to that of commercialized liquid natural gas (LNG) facilities, this study has concluded that thermal insulation structures satisfying large-tank requirements should be developed. In order to evaluate thermal performances of various devised insulation structures between 20 and 300K, we have developed a large experimental apparatus with a double-guarded flat plate boil-off calorimeter method. This apparatus can test various kinds of specimens with allowable dimensions; diameter 1.2m, up to thickness 0.3m, to provide the thermal data needed for designing a full-scale storage tank. This paper describes the abstract of the devised large-mass liquid hydrogen storage tank, the experimental errors of the experimental apparatus to be considered, and the results of the background and heater tests for evaluating its performance. The background test result showed that heat transfer to the measuring vessel was 0.1W, small enough to satisfy apparatus performance requirements.

A large experimental apparatus for measuring thermal conductance of LH2 storage tank insulations

In the Japanese hydrogen project, WE-NET (World Energy Net Work), the conceptual design of the large mass liquid hydrogen storage systems for ground tanks and transportation, whose scales would reach to that of commercialized LNG (liquid national gas), has been studied. This study has concluded that the thermal insulation for a mass storage tank, providing the excellent thermal performance with the optimized strength, should be developed. In order to evaluate thermal conductance of various devised insulations, we have manufactured a large-scale experimental apparatus. This apparatus, which adopts a double guarded flat plate boil-off calorimeter method, can provide the thermal data needed for designing a full-scale tank. It would be possible to test various kinds of specimens with allowable dimensions: diameter 120 cm, thickness up to 30 cm. In the case of a rigid specimen contacting bottom surfaces of liquid hydrogen vessels, the good flatness of their bottom plates is desirable to reduce the thermal resistance between vessels and a specimen surface. This paper describes the abstract of the developed apparatus, its structural design and also the experimental results for verifying its structural design.

Characterization And Potential Treatment of the Lindbergh Produced Sand

Abstract Experiments were carried out using a conventional flotation unit to study the feasibility of cleaning the sand produced from unconsolidated heavy oil formations. This study was undertaken to evaluate whether flotation treatment would produce a sand product that could be disposed of as clean fill. Results of the flotation tests indicate that more than 99% reduction in hydrocarbon and salt content could be achieved by treating the sand in a flotation unit. The addition of a surface active chemical (surfactant) enhanced the disengagement of hydrocarbon from the sand surfaces. The cleaning of the produced sand was achieved by using a sand-to-water ratio of 1:2 and a surfactant concentration of around 1,000 mg/kg of solid. Introduction Heavy oil production operation in Alberta generate large volumes of oil-waste material. Much of this waste is formation sand produced in conjunction with the heavy oil. The sand is lifted to the surface along with the produced fluids and collected in above ground tanks. In most operations, the oil and oil/water emulsion are subsequently hauled to a cleaning plant for separation, the sand is transferred to a central storage pad, and the free water is taken for disposal. Noreen Energy Resources Limited produces heavy oil in the Lindbergh field of northeastern Alberta from shallow and unconsolidated sandstone formations (e.g., Basal Mannville and Rex). Norcen's Lindbergh operations produce three oily-waste streams (clean sand, oily sand, and slop oil), characterized by their different levels of primary contaminants (e.g., oil and chloride). The three waste streams are characterized in Table 1. Despite the lower levels of contamination in the clean sand, the large volumes of this stream make it the most difficult of the three to dispose. The low level of contaminants in the clean sand stream is a result of the process used by Norcen to remove the sand from the production tank at individual wellsites. The production tank at each well is first drained of produced fluids (i.e., oil and water) and filled with hot fresh water. The fresh water and sand are agitated and removed from the tank using a stinger and vacuum truck. The use of heated fresh water reduces the chloride content of the sand to below 2,000 mg/kg and the oil content to approximately 1% (w/w). This clean sand is then hauled and stored on a centralized asphalt pad to await final disposal. The method currently employed to dispose of the clean-sand stream is by road-bed construction in the Lindbergh area. The government agencies responsible for waste disposal in the oil industry have recently indicated that this method will not be permitted over the long term because of the hydrocarbon, chloride, and possibly the BTEX (benzene, toluene, ethylbenzene, and xylene) content and that alternate solutions should be sought. Recently, Norcen has completed an in-depth study of the treatment and disposal alternatives that may be applicable to the clean sand waste stream. Consideration of numerous criteria including cost and long-term liability indicated that an on-site soil washing process may be an attractive method of reducing the contamination to a level that would make the sand suitable for use as clean fill.

Technical note: Improved cathodic protection under above ground tank with coating containing solid electrolyte

A new technique for controlling the external corrosion of above ground storage tank bottoms has been developed, based on the combined application of a special coating system and impressed current cathodic protection. It is characterised by a specially formulated paint which contains the solid electrolyte sodium β” (β)-alumina as an ionically conducting component. Because of the close proximity of the cathodically protected surface to the coating anode, the approach has significant advantages over conventional cathodic protection systems. The feasibility of the proposed technique has been verified both by laboratory tests and in practical applications.

Assessing the structural integrity and leak tightness of above ground tanks using acoustic emission technology

Assessing the structural integrity and leak tightness of above ground tanks using acoustic emission technology

Space construction results: The EASE/ACCESS flight experiment

This paper describes NASA ground and flight test activities in the development of in-space construction techniques for the assembly of Space-Station-sized structures. In November 1985, the first experiments on space construction using EVA astronauts were flown aboard the Space Shuttle, with spectacular and highly visible results. The EASE and ACCESS flight experiments are described and the ground and water tank test program and operations in-flight including instrumentation are presented, together with illustrations of assembly and disassembly of both the EASE and ACCESS experiments. The flight test results are presented and learning and productivity curves are discussed, with differences between free EVA vs EVA using foot restraints compared. Two weeks after the flights, the Space Station structural assembly technique was selected to be EVA astronaut assembly of the truss, based on the flight experiment results.

A MOBILE PLANT PROTOTYPE FOR THE RESTORATION OF POLLUTED BEACHES BY WASHING OILY SAND

ABSTRACT A research program was undertaken in 1980 with the support of the European Economic Community and the French Ministry of the Environment to develop a technique for treating beaches polluted by an oil spill, after the bulk of the oil has been removed from the surface of the sand by mechanical equipment. Final cleanup is often necessary, especially in the case of recreational beaches, when the oil remaining in the upper layer of sand—frequently in the range of 2 to 3 percent—in unacceptable. There is some controversy regarding the use of dispersants for this purpose. The basic principle of the technique is to wash oil-contaminated sand in transportable equipment which is operated either close to the polluted beach or at a centralized location, the washed sand then being returned to the beach or used for other purposes. The selected equipment and three different cleaning agents were tested in pilot trials carried out on sand polluted with heavy fuel oil. A plant prototype was set up and tested in 1985. It is composed mainly of a horizontally rotating wash drum associated with a screen, a hydrocyclone to separate the sand from the wash-water phase and a vibrating screen for sand dewatering. These three pieces of equipment are mounted on the bed of a semi-trailer along with two transfer pumps. Oil and sand fines are separated from the water, before recycling, in several ground tanks in which a flocculating agent may be added. The operating parameters of the process are discussed on the basis of trials carried out at a throughput of 18 metric tons of sand per hour, giving a washed sand with an average oil content of 0.2 percent in the case of moderate weathering.

Bacteriological Quality of Rainwater in Roof and Ground Catchment Systems in Botswana

ABSTRACT Bacteriological analyses were conducted on water samples from 13 roof tanks and 8 ground catchment tanks in Botswana in 1983. The results show that rainwater collected from corrugated iron roofs and stored in covered tanks is of high quality compared with traditional water sources and could provide a safe drinking water supply. The results for the ground catchment tanks, however, indicated that the water posed a serious health hazard. This is significant since several hundred ground tanks are already being used to provide water for other things besides human consumption. Since more ground tanks are planned both in Botswana and elsewhere in Africa the fencing of the catchment area and the use of simple sand and charcoal filters are recommended as the most practical means of insuring improved water quality in ground tanks.

Transplant Studies With Physa anatina Lea (Gastropoda) in Andrews County, Texas

Transplant studies and water analyses indicate that the absence of P. anatina in some stock ponds in the Southwest is due to unfavorable conditions rather than to failure of the snails to disperse. INTRODUCTION AND METHODS In portions of the southwestern United States there are numer- ous artificial stock ponds. In many cases the water supply for these ponds is derived from a subterranean well equipped with a windmill. Water is pumped into a metal or concrete open ground tank supplied with an overflow, allowing water to enter a dirt holding pond. Thus, there are two bodies of water, the tank and the pond, both of which are usually rather small. An average tank holds about 150 ft3 of water and a typical pond has a capacity seldom exceeding 20,000 ft3. Since there is a rather constant water supply, stock ponds of this type are permanent. Pennak (1958) emphasized the importance of these aquatic habitats as stepping stones enabling invertebrates to dis- perse with greater ease. Pennak further indicated that the biology of western stock ponds has been entirely neglected. From September, 1963, to September, 1964, a total of 49 such ponds were inspected in Andrews County, Texas. At least 20 were visited each month, with the exception of December, and all 49 were checked during November, March, and May. A total of 18 of the ponds were inhabited by Physa anatina Lea. Snails were found in both the tank and the pond at each of these locations. Since snails were not found in 31 of the ponds, an obvious ques- tion is whether the species is absent because it has not been trans- ported there or because the habitat is unsuitable for its establishment. All the ponds are located in mesquite pasture land having sandy soil, and from outward appearances the environments of all are similar. But since they are supplied by ground water, it is likely that the chemical characteristics vary considerably from pond to pond. To be uniform habitats, the water supply of each pond would have to be derived from the same underground strata or stream. Such is probably not the case since the ponds are spread over an area of about 625 square miles. To obtain information bearing on the problem, ten stock ponds that contained no snails were chosen for transplant studies. If the habitats were suitable, introduced snails would presumably thrive, suggesting that their previous absence from the ponds was due to a lack of dispersal. On the other hand, if the snails failed to survive, unfavorable habitats would be indicated, and natural introduction of the species would not be expected to result in its successful establish- 325

IPA-95 based resins shown superior for above ground tank linings these eight ways.

IPA-95 based resins shown superior for above ground tank linings these eight ways.