1、Designation: F 1778 97 (Reapproved 2002)Standard Guide forSelection of Skimmers for Oil-Spill Response1This standard is issued under the fixed designation F 1778; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last rev
2、ision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers considerations for selecting skimmersystems for the recovery of marine-oil spills. The purpose ofthis guide
3、 is to provide oil spill response planners, equipmentmanufacturers, users, and government agencies with a standardon the equipment selection process for the removal of oil fromthe marine environment.1.2 This guide does not address the compatibility of spill-control equipment with spill products. It
4、is the users respon-sibility to ensure that any equipment selected is compatiblewith anticipated products and conditions.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-p
5、riate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2F 625 Practice for Classifying Water Bodies for Spill Con-trol SystemsF 631 Guide for Collecting Skimmer Performance Data inControlled Environments3. T
6、erminology3.1 Definitions:3.1.1 encounter ratethe volume of oil per unit timeactively directed to the removal mechanism.(F 631)3.1.2 nameplate recovery ratethe maximum skimmingcapacity of a device under optimum conditions of oil type,slick conditions, and environmental conditions.3.1.3 oil recovery
7、ratethe volume of oil recovered by thedevice per unit time.(F 631)3.1.4 recovery effciencythe ratio, expressed as a percent-age, of the volume of oil recovered to the volume of total fluidsrecovered.(F 631)3.1.5 throughput effciencythe ratio, expressed as a per-centage, of the volume of oil recovere
8、d to the volume of oilencountered.(F 631)4. Significance and Use4.1 This guide is intended to facilitate the oil spill responseequipment selection process for local, regional, and nationalspill response teams. It is not intended to define rigid sets ofequipment standards.4.2 The effectiveness of the
9、 equipment chosen to combat anoil spill will depend on the oil type and environment(s)encountered, as well as other factors. This guide is intended tobe used by persons generally familiar with the practical aspectsof oil spill cleanup operations including on-scene responsecoordinators, planners, oil
10、 spill management teams, oil spillremoval organizations, and plan evaluators.4.3 Eleven general types of skimming systems are describedin this guide. Each description includes a summary of theoperating principle and a list of selection considerations.4.4 Selection considerations are included to guid
11、e the useron the selection of a particular skimmer type or category. Usersare cautioned that within each category there may be a widevariation in performance among various skimmers.4.5 When selecting a skimmer for use in extremely coldconditions, consideration should be given to the effect of icefor
12、ming on the skimmer, changes in buoyancy, possible restric-tion of inlets, and changes to hydraulic efficiency. Becausethere may be wide variations in skimmer performance atextreme temperatures, even within a given category, ambienttemperature is not included as a selection consideration.5. Skimmer
13、Selection Considerations5.1 Selecting a type of skimmer for a given applicationinvolves examining the skimmers likely performance againsta range of operational requirements. The following are recom-mended as a guide to this process, with the requirementsgrouped according to the operating environment
14、, the slickconditions, and skimmer performance criteria. Comments on1This guide is under the jurisdiction of ASTM Committee F20 on HazardousSubstances and Oil Spill Response and is the direct responsibility of SubcommitteeF20.12 on Removal.Current edition approved Oct. 10, 2002. Published February 2
15、003. Originallyapproved in 1997. Last previous edition approved in 1997 as F 1778 97.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary
16、page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.each of these operational requirements, specific to each skim-ming type, are given in Section 6.5.2 Operating Environment:5.2.1 Wave ConditionsDepending on the t
17、ype of skimmer,waves may affect both the oil-recovery rate and the oil-recovery efficiency. In general, most skimmers work best incalm conditions with decreases in recovery rate and efficiencyas waves increase; in particular most skimmers are greatlyaffected by short choppy waves. For each skimming
18、type,comments are given on the sensitivity to different waveenvironments. (Classification information for calm, protected,and open-water environments is given in Practice F 625.)5.2.1.1 Additional considerations for selecting skimmers forparticular wave conditions are that both the skimming devicean
19、d the required support platform are applicable to the intendedenvironment.5.2.2 CurrentsShould the operating environment of con-cern have significant water currents, this should be consideredin the selection process. Many skimmers will not operateeffectively in currents greater than 1 knot due to de
20、creases inthroughput efficiency. On the other hand, several skimmingprinciples such as the sorbent belt, brush, submersion plane,advancing weir, and boom skimmers rely on relative currentfor effective operation and are applicable in currents greaterthan 1 knot. Several skimmer types such as the oleo
21、philic brushand oleophilic rope mop are available as well, in configurationsthat allow them to operate effectively in high currents.5.2.2.1 Comments on performance in currents are restrictedto those directly related to the skimming device. If containmentbooms are used to collect or concentrate oil,
22、or both, forskimming, additional operating limitations related to contain-ment boom performance in currents may also apply.5.2.3 Water DepthsWater depths may be a concern forskimming operations in nearshore waters and when supportinga shoreline cleanup operation. It is important to note that anydraf
23、t limitations would apply to both the skimming device aswell as the required support vessel; certain skimmer types,although not requiring deep water for their skimming compo-nent, may require large support vessels for deployment andoperation.5.2.3.1 While many skimming types are available in a range
24、of sizes that may allow their operation in shallow waters,certain types are generally applicable to shallow water depthsand these are noted in the skimmer descriptions. Skimmertypes in this category include rope mop skimmers, vacuumsystems, air conveyors, some weir skimmers, and some sorbentbelt ski
25、mmers.5.3 Slick Conditions:5.3.1 Oil Type and ViscosityFew skimming principlesoperate with optimum effectiveness over a wide range of oilviscosities. For many skimmers, recovery rates will tend to beless than the reported maximum rates for oils that have a verylow viscosity, and for oils that have a
26、 very high viscosity, eitherinitially or as a result of weathering or emulsification, or both.On the other hand, several skimming principles such as brush,drum, and paddle-belt skimmers operate most effectively withmore viscous oils.5.3.1.1 Recommended viscosities for skimmer performancedata are giv
27、en in Guide F 631. These include: 200, 2000, and60 000 mm2/s. These values are referred to in the skimmerselection considerations as low, medium, and high viscosityoil.5.3.2 Slick ThicknessSlick thickness greatly affects therecovery rate of virtually all skimming principles, nameplaterecovery rates
28、only being achieved with thick slicks. Slickthickness also affects the recovery efficiency of most skimmers,in particular those employing suction or weir skimming prin-ciples. On the other hand, many skimmers can deal effectivelywith thin slicks by varying the operating parameters of thedevice (that
29、 is, for oleophilic devices, by reducing the speed ofthe oleophilic element, and by adjusting the weir settings forweir devices).5.3.2.1 In evaluating a skimming principle based on ex-pected slick thickness, consideration should be given towhether containment booms can be used to concentrate oil for
30、recovery.5.3.2.2 In the skimmer descriptions in Section 6, referenceis made to device performance in thin slicks, which is definedas continuous slicks less than 1 mm in thickness, or discon-tinuous patches of oil with an average thickness of less than 1mm.5.3.3 DebrisThe presence of debris presents
31、two concernsin a skimming operation: first; that debris may restrict flow tothe skimming head, and second, that debris may interferedirectly with the skimming component (that is, clogging orobstructing openings, impeding moving parts). Some skim-ming types, such as most oleophilic devices, are large
32、lyinsensitive to the presence of debris. Suction and air conveyordevices are generally tolerant of debris up to the size of thetransfer hoses used. Weir devices, in general, are susceptible toclogging with debris; however, many weir devices use integraltransfer pumps that can process a range of debr
33、is types. Whereapplicable, comments are made on debris tolerance or sensi-tivity in the selection considerations comments. It should benoted that these comments pertain to the general skimmingtype, and that certain skimmers within a given category mayinclude means of dealing with debris. Guidance fo
34、r a range ofdebris types respecting skimmer performance can be takenfrom Guide F 631, which lists a number of debris forms forskimmer testing.5.4 Performance Requirements:5.4.1 Recovery RateFor some applications the most im-portant performance criteria will be the product recovery rate.Although the
35、various skimming categories are available in arange of sizes and capacities, generalizations can be made onexpected recovery rates. In this guide, comments are made onexpected recovery rates only as they would apply to the variousskimming principles and not to particular devices. For ex-ample, weir
36、skimmers and boom skimmers are available withhigh nameplate recovery rates, limited only by the availablepumping capacity. On the other hand, oleophilic skimmers tendto have a fixed upper limit of recovery depending on the sizeof the oleophilic surface used (that is, surface area of discs,length and
37、 diameter of rope mop).F 1778 97 (2002)25.4.1.1 Although specific skimmer performance data are notincluded in this guide, users are reminded that a skimmersnameplate recovery rate should be used with caution as it maynot accurately reflect skimmer performance under varyingconditions of slick thickne
38、ss, slick viscosity, and environmen-tal parameters. Where possible, performance data based onfield use or experiments should be used, with reference to theslick and environmental conditions of particular concern to theuser.5.4.2 Recovery EffciencySelection of a skimmer based onthe expected recovery
39、efficiency may be particularly importantdepending upon the availability of storage, the availability ofsystems to separate free water from the recovered fluids, andthe permissibility of discharging decanted water at the recoverysite. The expected recovery efficiency will, for most skimmingcategories
40、, vary greatly depending on the thickness and vis-cosity of the slick and on the environmental conditions at thespill site.5.4.2.1 In general, skimmers using oleophilic principles canbe expected to have higher recovery efficiencies relative toskimmers using weir or suction principles. Among weir ski
41、m-mers, devices in the induced flow category can be expected tohave a high efficiency. As well, several skimming categoriesare typically configured with onboard gravity separation,which would enhance their overall efficiency. For skimmerswithout onboard separation, oil/water separation should becons
42、idered to maximize the use of available storage.5.4.3 Mode of ApplicationComments on the mode ofapplication include the ability to use in an advancing mode andthe applicability to use on a vessel-of-opportunity.5.4.3.1 Certain skimmer categories, such as oleophilic disc,rope mop, and some weir skimm
43、ers are not generally used inan advancing mode. Conversely, devices such as the boomskimmer, the fixed submersion plane, paddle belt, and oleo-philic brush skimmers require relative forward motion foreffective operation.5.4.3.2 Vessel-of-opportunity application will in many casesbe specific to a ski
44、mming device rather than a skimmingcategory. However for those skimming categories that aretypically used with vessels-of-opportunity, this is noted in theselection considerations.6. Description of Main Skimming Types6.1 The following describes the operating principles andkey selection consideration
45、s of eleven main types of skimmingsystems. In several instances, subcategories are used to de-scribe different configurations of a common operating prin-ciple.6.2 Boom Skimmers:6.2.1 DescriptionBoom skimmers include any device inwhich the skimmer is incorporated in the face of the contain-ment boom,
46、 regardless of the skimmer type. This system caninclude a single skimmer installed in the face of the boom, butin many examples of this concept there are several skimmersused. In most boom skimmers, weir-type skimmers are used.Boom skimmers provide a combined containment and recoverysystem.6.2.1.1 O
47、il spill containment boom is often attached to eachside of the mouth of a skimmer in order to increase the sweepwidth. Although such a system would be similar to a boomskimmer, it would not meet the definition of a boom skimmerbecause the skimmer in the system could be used apart fromthe boom. In a
48、boom skimmer, the skimmer is part of the boomand is not intended to be used by itself.6.2.2 Selection Considerations:6.2.2.1 Oil TypeApplicable to low and medium viscosityoils.6.2.2.2 Debris ToleranceDebris must be screened or re-moved from the skimmer opening.6.2.2.3 Wave ConditionsRecovery rate an
49、d efficiency de-graded by choppy waves.6.2.2.4 CurrentsMay be operated at currents greater thanone knot, at reduced recovery efficiency, by pumping at a highrate.6.2.2.5 Water DepthGenerally limited by towing vessels.6.2.2.6 Mode of ApplicationRequires relative forwardvelocity: may be operated in stationary mode if current present.6.2.2.7 OtherTypically designed for vessel-of-opportunity application.6.3 Brush Skimmers:6.3.1 DescriptionBrush skimmers are oleophilic skim-mers that pick up oil on the bristles of a brush. There are twomain configurations for
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1