1、Designation: F 1778 97 (Reapproved 2008)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 () 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 i
4、s the users respon-sibility to ensure that any equipment selected is compatiblewith anticipated products and conditions.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of the
5、safety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate 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 Classifyi
6、ng Water Bodies for Spill Con-trol SystemsF 631 Guide for Collecting Skimmer Performance Data inControlled Environments3. Terminology3.1 Definitions:3.1.1 encounter ratethe volume of oil per unit timeactively directed to the removal mechanism. F 6313.1.2 nameplate recovery ratethe maximum skimmingca
7、pacity of a device under optimum conditions of oil type,slick conditions, and environmental conditions.3.1.3 oil recovery ratethe volume of oil recovered by thedevice per unit time. F 6313.1.4 recovery effciencythe ratio, expressed as a percent-age, of the volume of oil recovered to the volume of to
8、tal fluidsrecovered. F 6313.1.5 throughput effciencythe ratio, expressed as a per-centage, of the volume of oil recovered to the volume of oilencountered. F 6314. Significance and Use4.1 This guide is intended to facilitate the oil spill responseequipment selection process for local, regional, and n
9、ationalspill response teams. It is not intended to define rigid sets ofequipment standards.4.2 The effectiveness of the 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 fa
10、miliar with the practical aspectsof oil spill cleanup operations including on-scene responsecoordinators, planners, oil 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 sum
11、mary of theoperating principle and a list of selection considerations.4.4 Selection considerations are included to guide 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.
12、4.5 When selecting a skimmer for use in extremely coldconditions, consideration should be given to the effect of iceforming 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
13、temperatures, even within a given category, ambienttemperature is not included as a selection consideration.5. Skimmer Selection Considerations5.1 Selecting a type of skimmer for a given applicationinvolves examining the skimmers likely performance againsta range of operational requirements. The fol
14、lowing are recom-mended as a guide to this process, with the requirementsgrouped according to the operating environment, 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
15、the direct responsibility of SubcommitteeF20.12 on Removal.Current edition approved Sept. 15, 2008. Published September 2008. Originallyapproved in 1997. Last previous edition approved in 2002 as F 1778 97 (2002).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Cu
16、stomer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary 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 require
17、ments, specific to each skim-ming type, are given in Section 6.5.2 Operating Environment:5.2.1 Wave ConditionsDepending on the type 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
18、 rate and efficiencyas waves increase; in particular most skimmers are greatlyaffected by short choppy waves. For each skimming type,comments are given on the sensitivity to different waveenvironments. (Classification information for calm, protected,and open-water environments is given in Practice F
19、 625.)5.2.1.1 Additional considerations for selecting skimmers forparticular wave conditions are that both the skimming deviceand the required support platform are applicable to the intendedenvironment.5.2.2 CurrentsShould the operating environment of con-cern have significant water currents, this s
20、hould be consideredin the selection process. Many skimmers will not operateeffectively in currents greater than 1 knot due to decreases inthroughput efficiency. On the other hand, several skimmingprinciples such as the sorbent belt, brush, submersion plane,advancing weir, and boom skimmers rely on r
21、elative currentfor effective operation and are applicable in currents greaterthan 1 knot. Several skimmer types such as the oleophilic 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 curre
22、nts are restrictedto those directly related to the skimming device. If containmentbooms are used to collect or concentrate oil, 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 f
23、orskimming operations in nearshore waters and when supportinga shoreline cleanup operation. It is important to note that anydraft 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 comp
24、o-nent, may require large support vessels for deployment andoperation.5.2.3.1 While many skimming types are available in a rangeof 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. Ski
25、mmertypes in this category include rope mop skimmers, vacuumsystems, air conveyors, some weir skimmers, and some sorbentbelt skimmers.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, rec
26、overy rates will tend to beless than the reported maximum rates for oils that have a verylow viscosity, and for oils that have a 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-
27、belt skimmers operate most effectively withmore viscous oils.5.3.1.1 Recommended viscosities for skimmer performancedata are given 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.
28、2 Slick ThicknessSlick thickness greatly affects therecovery rate of virtually all skimming principles, nameplaterecovery rates only being achieved with thick slicks. Slickthickness also affects the recovery efficiency of most skimmers,in particular those employing suction or weir skimming prin-cipl
29、es. On the other hand, many skimmers can deal effectivelywith thin slicks by varying the operating parameters of thedevice (that 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
30、based on ex-pected slick thickness, consideration should be given towhether containment booms can be used to concentrate oil forrecovery.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 thi
31、ckness, or discon-tinuous patches of oil with an average thickness of less than 1mm.5.3.3 DebrisThe presence of debris presents two concernsin a skimming operation: first; that debris may restrict flow tothe skimming head, and second, that debris may interferedirectly with the skimming component (th
32、at is, clogging orobstructing openings, impeding moving parts). Some skim-ming types, such as most oleophilic devices, are largelyinsensitive 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
33、, are susceptible toclogging with debris; however, many weir devices use integraltransfer pumps that can process a range of debris types. Whereapplicable, comments are made on debris tolerance or sensi-tivity in the selection considerations comments. It should benoted that these comments pertain to
34、the general skimmingtype, and that certain skimmers within a given category mayinclude means of dealing with debris. Guidance for 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
35、.4.1 Recovery RateFor some applications the most im-portant performance criteria will be the product recovery rate.Although the various skimming categories are available in arange of sizes and capacities, generalizations can be made onexpected recovery rates. In this guide, comments are made onexpec
36、ted recovery rates only as they would apply to the variousskimming principles and not to particular devices. For ex-ample, weir skimmers and boom skimmers are available withhigh nameplate recovery rates, limited only by the availablepumping capacity. On the other hand, oleophilic skimmers tendto hav
37、e a fixed upper limit of recovery depending on the sizeof the oleophilic surface used (that is, surface area of discs,length and diameter of rope mop).F 1778 97 (2008)25.4.1.1 Although specific skimmer performance data are notincluded in this guide, users are reminded that a skimmersnameplate recove
38、ry rate should be used with caution as it maynot accurately reflect skimmer performance under varyingconditions of slick thickness, slick viscosity, and environmen-tal parameters. Where possible, performance data based onfield use or experiments should be used, with reference to theslick and environ
39、mental conditions of particular concern to theuser.5.4.2 Recovery EffciencySelection of a skimmer based onthe expected recovery efficiency may be particularly importantdepending upon the availability of storage, the availability ofsystems to separate free water from the recovered fluids, andthe perm
40、issibility of discharging decanted water at the recoverysite. The expected recovery efficiency will, for most skimmingcategories, 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 pri
41、nciples canbe expected to have higher recovery efficiencies relative toskimmers using weir or suction principles. Among weir skim-mers, devices in the induced flow category can be expected tohave a high efficiency. As well, several skimming categoriesare typically configured with onboard gravity sep
42、aration,which would enhance their overall efficiency. For skimmerswithout onboard separation, oil/water separation should beconsidered 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 applicabi
43、lity to use on a vessel-of-opportunity.5.4.3.1 Certain skimmer categories, such as oleophilic disc,rope mop, and some weir skimmers 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
44、 relative forward motion foreffective operation.5.4.3.2 Vessel-of-opportunity application will in many casesbe specific to a skimming device rather than a skimmingcategory. However for those skimming categories that aretypically used with vessels-of-opportunity, this is noted in theselection conside
45、rations.6. Description of Main Skimming Types6.1 The following describes the operating principles andkey selection considerations 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 Skim
46、mers:6.2.1 DescriptionBoom skimmers include any device inwhich the skimmer is incorporated in the face of the contain-ment boom, 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 skimmersus
47、ed. In most boom skimmers, weir-type skimmers are used.Boom skimmers provide a combined containment and recoverysystem.6.2.1.1 Oil 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 boomskim
48、mer, it would not meet the definition of a boom skimmerbecause the skimmer in the system could be used apart fromthe boom. In a 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 viscosityo
49、ils.6.2.2.2 Debris ToleranceDebris must be screened or re-moved from the skimmer opening.6.2.2.3 Wave ConditionsRecovery rate and 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 Descr
